Catalytic Converter Or a 12-R CABOT ROAD Particulate Filter

US 2008O112865A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2008/0112865 A1 Alward et al. (43) Pub. Date: May 15, 2008

(54) NONWOVEN COMPOSITES AND RELATED Publication Classification PRODUCTS AND METHODS (51) Int. Cl. BOID 53/94 (2006.01) (75) Inventors: Gordon S. Alward, Del Mar, CA (US); Robert A. DiChiara, (52) U.S. Cl...... 423/212 Carlsbad, CA (US) (57) ABSTRACT The present invention in certain embodiments is directed to a Correspondence Address: catalytic Substrate Suitable for use in a number of applica GEO2 TECHNOLOGIES tions, including as a Substrate in a catalytic converter or a 12-R CABOT ROAD particulate filter. Another aspect of the present invention is a WOBURN, MA 01801 filtering Substrate Suitable for use in a number of applications, including as a Substrate in a particulate filter, Such as a diesel (73) Assignee: GEO2 TECHNOLOGIES, INC., particulate filter (DPF), or diesel particulate trap (DPT). The Woburn, MA (US) invention also provides an improved Substrate for removing and/or eliminating pollutants from the exhaust of combustion Appl. No.: 11/869,139 engines. The catalytic Substrate and filtering Substrate pro (21) vide, in certain embodiments, improvements in removing pollutants from an exhaust gas. The improvements include (22) Filed: Oct. 9, 2007 one or more of the following: faster light-off period, depth filtration of PM, less backpressure, lower probability of clog Related U.S. Application Data ging, ability to be placed in multiple locations in the exhaust (60) Division of application No. 10/833,298, filed on Apr. system including the manifold or the head itself, high prob 28, 2004, which is a continuation-in-part of applica ability of catalytic reaction, high conversion ratios of NOx, tion No. 10/281,179, filed on Oct. 28, 2002, now Pat. HC, and CO, a faster burnoff of PM, minimization of catalyst No. 6,946,013. material use, and the like.

Head Particulate Filter or Catalytic converter comprising Su E. of the invention positioned between engine head An xhaust manifold.

f Exhaust Exhaust flow Manifold

Catalytic converter or Particulate Filter Patent Application Publication May 15, 2008 Sheet 1 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 2 of 54 US 2008/O112865 A1

s Patent Application Publication May 15, 2008 Sheet 3 of 54 US 2008/O112865 A1 :

s s

O w CN Patent Application Publication May 15, 2008 Sheet 4 of 54 US 2008/O112865 A1

009

9.*£)|[[H (L’HVRHOI?Id) Patent Application Publication May 15, 2008 Sheet 5 of 54 US 2008/O112865 A1

r O O r O a r N S A

rS 2.

Patent Application Publication May 15, 2008 Sheet 7 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 8 of 54 US 2008/O112865 A1

O or \O Patent Application Publication May 15, 2008 Sheet 9 of 54 US 2008/O112865 A1

s O w N

s s Patent Application Publication May 15, 2008 Sheet 10 of 54 US 2008/O112865 A1

acces Patent Application Publication May 15, 2008 Sheet 11 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 12 of 54 US 2008/O112865 A1

O w O w

Patent Application Publication May 15, 2008 Sheet 13 of 54 US 2008/O112865 A1 s

:::::::::::::

t 3. : it. t h r

.. .*.*.*.*. s: .*.* r r h r .." : : . ww. :::::::::::::: r :::::: :::::: 3. Patent Application Publication May 15, 2008 Sheet 14 of 54 US 2008/O112865 A1

CN w O w s

Patent Application Publication May 15, 2008 Sheet 15 of 54 US 2008/O112865 A1 8

Patent Application Publication May 15, 2008 Sheet 16 of 54 US 2008/O112865 A1

O O w CN w w w w

Patent Application Publication May 15, 2008 Sheet 17 of 54 US 2008/O112865 A1

ZI"?INH

0ZZ| ZZZ| Patent Application Publication May 15, 2008 Sheet 18 of 54 US 2008/O112865 A1

É Patent Application Publication May 15, 2008 Sheet 19 of 54 US 2008/O112865 A1

5. Patent Application Publication May 15, 2008 Sheet 20 of 54 US 2008/O112865 A1

lf) er Or w

Patent Application Publication May 15, 2008 Sheet 24 of 54 US 2008/O112865 A1

S. 3.

S Patent Application Publication May 15, 2008 Sheet 25 of 54 US 2008/O112865 A1

s'sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss saxxx-x-xx-xx-x-xx-xx-xx-xxxxxx-x-xxxxxx-xx-xxxxxx-x-xxx-xx-xxxxx-x-xxxxxx-xxxx Axxxxx xxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxx xxxxxxx-xxxxxxxx xxxxxxx xxxxxx xxxxx-xxxxxxxxx xxxxx-x-xxxxxxxx xxxxxxx. xxxxxxxxx xxxx xxxxxxxxxxx xxxxxxxxx xxxx xxxxxxxxxxx xxxxxxxxx xxxx xxxxxxxxxxx xxxxxxxxx xxxx xxxxxxxxxxx xxxxxxxxxxx xxxx xxxxxx. Rsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssassal asssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss NYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY www.xxxx. awarxxx. xxxxxxxxxxxxxxxx xxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxx Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss ax, Raxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx asssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss syssesssssssssssssssssssssssssssssssssssssssssssssssssssssss. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Saxxxxxx-xx-xxxxxxxx-x-xxxxxxxx-xx-xxxxxxx-x-xxxxxxxx-xx-xxxxxxxx-x-xxxxxxxx-xx-xxxxxxx-x-xxxxxxxx xxxx. * sax - - - - XXX XXX s&K. SassasssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXV Sws XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXX XXX s&K. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXxxxxxxxxxxxxxxxx Sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss' SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSYsixxxx-x-xxx-x-xxx-xx-xx-xx-xxxx-x-xxx-xx-xxxxx-x-xxx-xx-xxxxx-xx NSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS SSXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX R Ssssssssssssssss SSSSS SSSSS SSSSS SSSSS SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS SSSSS SSSSS SS NSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS XxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Saaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSsssssssssssssssssssssssssssssssssssssssssssssssssssss asssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS *Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxasays assassy XXXYYXXXXXXXXXXXxxxxxxxxxxYxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxYxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-xxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-xx-xx-xxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx-xx-xx-xxxxxxxx xxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxx xxxxxxxx xxxxxxxxxxx xxxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxxxx xxxxx xxxxx xxxxxxxxxxxx xxxxxxx. swassssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss. t assassissssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss assssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss. an. Waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaas axxx xxxxxx. Saxxxxxxxxx-xxxx t xxxx. asssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Sxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx assssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssy. AXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX saxxxxxxx xxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxxxx xxxxxxxxxx xxxxx Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Ssssssssssssssssssssssssssssssssssssssssssssssssssssxxxxx-xx-xxx-xxx-xxx-xxx-xx-xxx-xx-xx-xx-xx-xx-xx-xx-xxx-xx-xxx-xxx-xx-xx-xxx-xx-xx-xxx-xx-xx-xxxx SSSSSSSSSSSSSSSSSSarassssssssarassssssssssssssssssssssssssssssssssssssssssssssssssssarass. NSXSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS S&xxx-xx-x-xxx-xx-x-xx-xx-xxx-x-xxx-xxx-xx-xx-xxx-x-xxx-xxx-xx-xx-xxx-x-xx-xx-xxx-xx-xx-xx-x-x Sixxx-xxxxxxxxxx-xxxxxxxxxx-x-xxxxxxxxxx-xxxxxxxxxx-x-xxxxxxxx-x-xxxxxxxx-xx-xxxxxxxxxx-xxxxxxxxxx-x-xxxxxxxxx, SsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS SsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS S. Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss KK-S-S-S-S-S-S-S-S-S-S-S-SS Sxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Sssssssssssssss ' '''''''''''''''''''''''''''' SSSSSS Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS SSXXXss-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-Xxx-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-s-

asssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX assasssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssissssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss *XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXsesssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Sasasaasaxxx. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxx SSXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX assassssssssssssssssssssssssssssssssssssssssssssssssssssssssss. ax an. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS axas. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS assasssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss. SRsssss xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx, Assasssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss Sixxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxxxx xxxxxxxxxx www.www.www.www.www.www.www. XXXXXXXXXXXXXXXXXXXXxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx axxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxsaxxxxxxxxxxxxx, : Patent Application Publication May 15, 2008 Sheet 26 of 54 US 2008/O112865 A1

s kassassas

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

vsk&s R

www.rssssssssswww.www.YYYYYYYYYYYYYYYYYYYYYYYYYYYY

Ssssssssssssssssssssssss 3.xxxxxxxxx,

xxxx-xx-xx-xx-xx-xx-xxxxxxxx:AAAAAAAAAAAAAAAAAAAMAAxxxx-xx-xx-xx-xx-xx-xxxxx ress

a------ryyyyyyyyyyyyyyyyyyyyyyyy

Sr...... ------.& ' '

errrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrar s s: A.

rrrrrrrr'sssssssssssssssssssssssssssssssssssss Patent Application Publication May 15, 2008 Sheet 27 of 54 US 2008/O112865 A1

CN r N C N w Patent Application Publication May 15, 2008 Sheet 28 of 54 US 2008/O112865 A1

8I"?INH

Patent Application Publication May 15, 2008 Sheet 29 of 54 US 2008/O112865 A1

\O O ON w

- f |- saa |pae«x ??&***************~~~~~~……………....*******«…,

SS&A 80S efSSBA 8S Patent Application Publication May 15, 2008 Sheet 30 of 54 US 2008/O112865 A1

NO S S s CN

O en d s

CN O O CN

s Patent Application Publication May 15, 2008 Sheet 31 of 54 US 2008/O112865 A1

: Patent Application Publication May 15, 2008 Sheet 32 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 33 of 54 US 2008/O112865 A1 : É

S. s

s Patent Application Publication May 15, 2008 Sheet 34 of 54 US 2008/O112865 A1

0||90 OOO‘000"|

ÇZ“?INH 000‘008000‘009000‘007 (uu/L)Á??ooleN30edSÁ?unoHseº 000°OOZ

OZHU eleO Patent Application Publication May 15, 2008 Sheet 35 of 54 US 2008/O112865 A1

JR3 ISS, Patent Application Publication May 15, 2008 Sheet 36 of 54 US 2008/O112865 A1

i O lf) w w l?) lf) f CN CN Patent Application Publication May 15, 2008 Sheet 37 of 54 US 2008/O112865 A1

s i

s Patent Application Publication May 15, 2008 Sheet 38 of 54 US 2008/O112865 A1

QLZ

LZBLZ“?IH0|| Patent Application Publication May 15, 2008 Sheet 39 of 54 US 2008/O112865 A1

Z9.InãIH •Žø.

Patent Application Publication May 15, 2008 Sheet 40 of 54 US 2008/O112865 A1

(uudis)æqeu?wol-iseºZN Patent Application Publication May 15, 2008 Sheet 41 of 54 US 2008/O112865 A1

r Patent Applicat US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 43 of 54 US 2008/O112865 A1

(£14/#9INo.No.T

ASHE),"SådE?IECI

OHL de Patent Application Publication May 15, 2008 Sheet 44 of 54 US 2008/O112865 A1

C NJ T ~] ~ -U © Q Patent Application Publication May 15, 2008 Sheet 45 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 46 of 54 US 2008/O112865 A1

OCHU) d2O

Patent Application Publication May 15, 2008 Sheet 49 of 54 US 2008/O112865 A1

SLSTV/HXEEINI3)NETEISEIICINILNEMINE/AOBHCHINI 89"?INH XO??****************

(IL-d/Luf) XON Patent Application Publication May 15, 2008 Sheet 50 of 54 US 2008/O112865 A1

You. a. -- ---

69"?INH

j:*13. UIO!]nq?J?SICIOZIS0?BIn0!!-IBAIIÐSðICI

(i. &lii Lice.e3 page. CN

Patent Application Publication May 15, 2008 Sheet 51 of 54 US 2008/O112865 A1

NOIJLVRIJLTIHHALCH?HCI **** Patent Application Publication

Patent Application Publication May 15, 2008 Sheet 53 of 54 US 2008/O112865 A1

Patent Application Publication May 15, 2008 Sheet 54 of 54 US 2008/O112865 A1

US 2008/01 12865 A1 May 15, 2008

NONWOVEN COMPOSITES AND RELATED Both kinds of pollutants can also be produced from non PRODUCTS AND METHODS engine sources, such as "off-gas' chemical reactions and evaporative emissions. CROSS-REFERENCE TO RELATED 0005 Air pollution can cause serious health problems for APPLICATIONS people and the environment. Ground-level oZone and air 0001. This application includes material which is subject borne particles are the two pollutants that pose one of the to copyright protection. The copyright owner has no objection greatest threats to human health in this country. Ozone (O), to the facsimile reproduction of the patent disclosure, as it can irritate the respiratory system, causing coughing, irrita appears in the United States Patent and Trademark Office files tion in the throat, and/or a burning sensation in the respiratory or records, but otherwise reserves all rights. This application airways. OZone contributes to the formation of Smog. OZone is a divisional application of U.S. patent application Ser. No. can also reduce lung function, causing feelings of chest tight 10/833.298 filed Apr. 28, 2004, which is a continuation-in ness, wheezing and shortness of breath, and can aggravate part of U.S. patent application Ser. No. 10/281,179, filed Oct. asthma. Particle pollution, is composed of microscopic Solids 28, 2002, each are herein incorporated by reference in its or liquid droplets that are Small enough to get deep into the respective entirety. lungs and cause serious health problems. When exposed to these Small particles, people may experience nose and throat irritation, lung damage and bronchitis, and can increase their BACKGROUND OF THE INVENTION risk of heart or lung disease. Short-term effects of air pollut Field of the Invention ants include irritation to the eyes, nose, and throat. Upper respiratory infections such as bronchitis and pneumonia may 0002. This invention relates to substrates useful for cata also result. Other symptoms can include headaches, nausea, lyzing particular reactions and for filtering particulate matter, and allergic reactions. Long-term health effects can include and to embodiments related thereto, such as but not limited to chronic respiratory disease, lung cancer, heart disease, and the treatment of emissions from internal combustion engines, even damage to the brain, nerves, liver, or kidneys. Continual and more specifically to catalyst/substrate combinations use exposure to air pollution affects the lungs of growing children ful in emissions control and related processes and to related and may aggravate or complicate medical conditions in the products and methods of manufacture. It is believed that elderly. embodiments of the invention described herein materially 0006 Medical conditions arising from air pollution can be enhances the quality of the environment of mankind by con very expensive. Healthcare costs, lost productivity in the tributing to the restoration or maintenance of one or more workplace, and human welfare impacts cost billions of dol basic life-sustaining natural elements, including air, water, lars each year. Understanding the health effects of pollution and/or soil. The invention and embodiments thereofare more and finding means to ameliorate, prevent, or eliminate pollu fully described below in the Brief Summary of the Invention tion would not only enhance the overall respiratory health of and Detailed Description sections. the population but would also decrease the substantial burden Exhaust, Industry, and Pollution and cost borne by the healthcare system. 0007 For all of these reasons, governments, environmen 0003 Engines produce much of the power and mechanical tal agencies, and various industries have committed to reduc work used across the globe. The internal combustion engine is ing the level of air pollution emitted from various sources. perhaps the most widespread device, as it is more efficient Government agencies are the principal bodies setting emis than an external combustion engine, such as those that existed sions standards and implementing regulations. In the Euro on old-fashioned trains and steamboats. With internal com pean Union (EU), regulations stem from European Commu bustion engines, combustion of the fuel takes place internally. nity legislation; individual countries enforce the regulations. Such engines produce motion and power used for any number For instance, most EU States have taxes on sources that pro of purposes. Examples include motor vehicles, locomotives, duce excessive air pollution. A recent development was the marine applications, recreational vehicles, tractors, construc Kyoto Protocol, which called for worldwide reductions in tion equipment, generators, power plants, manufacturing greenhouse gases. Many nations, including the EU, ratified facilities, and industrial equipment. Fuels used to powerinter the protocol. The EU, Japan, and U.S. have enacted some of nal combustion engines include, but are not limited to gaso the most stringent standards worldwide, but many other coun line, compressed gas, diesel, ethanol, and vegetable oil. Inher tries, including Argentina, Brazil, Mexico, Korea, Thailand, ent inefficiencies in engine mechanics and the fuels used to India, Singapore, and Australia, have all enacted regulations power the them result in emissions of various pollutants. on air pollution. In the U.S., there are many different groups Thus, while they are a great innovation and convenience, the that affect regulations in certain geographies, such as: State millions of engines used throughout the world today repre environmental agencies (e.g., California Air Resources Board sent a Substantial source of air pollution. (CARB)), national parks, forest agencies, and the Mine 0004. There are two main types of pollutants produced by Safety and Health Administration. Some states and metro internal combustion engines: particulate and nonparticulate. politan areas that have failed national ambient air quality Particulate pollution is generally small Solids and liquid par standards (NAAOS) have been designated as “non-attain ticles. Examples include carbonaceous soot and ash, dust, and ment areas” and implement standards of their own. CARB other related particles. Nonparticulate pollutants include has historically been one of the strictest agencies regulating gases and Small molecules, such as carbon monoxide, nitro air pollution in the U.S. The chief U.S. regulatory agency, gen oxides, Sulfur oxides, unburned hydrocarbons, and Vola however, is the Environmental Protection Agency (EPA). It tile organic compounds. Particulate pollutants can be filtered was created by the Nixon administration in the 1970 amend from the exhaust and, in certain situations, further burned off. ments to the Clean Air Act (CAA) of 1963. The Clean Air Act Nonparticulate pollutants are converted to nonpollutants. is the comprehensive Federal law that regulates air emissions US 2008/01 12865 A1 May 15, 2008

from area, stationary, and mobile sources. (See, e.g., 42 U.S. ing operations, as well as windblown dust. Some particles are C. SS7401 et seq. (1970) of the Clean Air Act). The Clean Air emitted directly from their sources, such as Smokestacks and Act has had five majoramendments, the most recent of which cars. In other cases, gases such as Sulfuroxide, SO, NOx, and was in 1990. The 1990 amendments to the Clean Air Act in VOC interact with other compounds in the air to form fine large part were intended to meet unaddressed or insufficiently particles. Their chemical and physical compositions vary addressed problems such as acid rain, ground-level oZone, depending on location, time of year, and weather. In 1997, the stratospheric oZone depletion, and air toxics. These amend EPA added two new PM-2.5 standards, set at 15 micrograms ments required the EPA to issue 175 new regulations, includ per cubic meter (LGA) and 65 ug/m, respectively, for the ing automotive emissions, gasoline reformation, uses of annual and 24-hour standards. oZone depleting chemicals, etc. 0008 Following the Clean Air Act legislation, the EPA set 0013 Sulfur dioxide can be formed when fuel containing regulations for pollutants that are or could be harmful to Sulfur (such as coal and oil) is burned, for example, during people. This set of “criteria pollutants’ includes: (1) ozone metal Smelting and other industrial processes. (O); (2) lead (Pb); (3) nitrogen dioxide (NO); (4) carbon 0014. The last criteria pollutant, lead, was historically pro monoxide (CO); (5) particulate matter (PM); and (6) sulfur duced from use of leaded fuel in automobiles. As a result of dioxide (SO). Each criteria pollutant is described in turn. regulatory efforts to reduce the content of Pb in gasoline, the 0009 Ground-level ozone (a primary constituent of Smog) contribution from the transportation sector has declined over continues to be a pollution problem in the U.S. Ozone is not the past decade. Today, metals processing is the major source emitted directly into the air but is formed by the reaction of of Pb emissions to the atmosphere. Volatile organic compounds (VOCs) or reactive organic gases 0015 The Clean Air Act requires to EPA and states to (ROGs) and nitrogen oxides (NOx) in the presence of heat develop plans to meet national ambient air quality standards and sunlight. VOCs/ROGs are emitted from a various sources for these six criteria pollutants. Outside of the six is a separate including burning fuels, and from solvents, petroleum pro list of 188 “toxic air pollutants.” Examples of toxic air pol cessing, and pesticides, which come from Sources Such as lutants include benzene, found in gasoline; perchloroethyl motor vehicles, chemical plants, refineries, factories, con ene, emitted from Some dry cleaning facilities; and methylene Sumer and commercial products, and other industrial sources. chloride, used as a solvent and paint Stripper by a number of Nitrogen oxides are emitted from motor vehicles, power industries. Some air toxics are released from natural Sources, plants, and other sources of combustion. OZone and the pre but most originate from anthropogenic sources, including cursor pollutants that cause ozone also can be carried miles both mobile sources (e.g., cars, trucks, and buses) and sta from their original sources by wind. In 1997, the EPA revised tionary Sources (e.g., factories, refineries, and power plants). the national ambient air quality standards for OZone by replac The CAA required the EPA to have a two-phased program for ing the 1-hour oZone 0.12 parts per million (ppm) standard these 188 pollutants. The first phase consists of identifying with a new 8-hour 0.08 ppm standard. the sources of toxic pollutants and developing technology 0010 Nitrogen dioxide (NO) is a reactive gas that can be based standards to significantly reduce them. The EPA deter formed by the oxidation of nitric oxide (NO). Nitrogen oxides mined a list of over 900 stationary sources, which resulted in (NOx), the term used to describe NO, NO, and other oxides new air toxics emissions standards, affecting many industrial of nitrogen, play a major role in the formation of ozone and Sources, including: chemical plants, oil refineries, aerospace Smog. The major sources of man-made NOx emissions manufacturers, and steel mills, as well as Smaller sources, include high-temperature combustion processes, such as Such as dry cleaners, commercial sterilizers, secondary lead those occurring in automobiles, heavy construction equip Smelters, and chromium electroplating facilities. The second ment, and power plants. Home heaters and gas stoves also phase consists of strategies and programs for evaluating the produce Substantial amounts of NO. remaining risks and ensuring that the overall program has 0011 Carbon monoxide (CO) is a colorless, odorless, and achieved substantial reductions; this phase is still in progress. poisonous gas that can be formed by incomplete combustion 0016 Internal combustion engines are directly affected by of carbon in fuels. Motor vehicle exhaust contributes about these regulations since they emit criteria pollutants. These 60% of CO emissions in the U.S. In cities, as much as 95% of engines run on two fuel. The most common types of fuel used CO emissions may come from automobile exhaust. Other are: gasoline and diesel. Each type of fuel contains complex Sources of CO emissions include industrial processes, non mixtures of hydrocarbon compounds as well as traces of transportation fuel combustion, and natural Sources such as many other materials, including Sulfur. Even when burned wildfires. completely, these fuels produce pollutants. Moreover, 0012 Particulate matter (PM) is a term used for a mixture because no engine is capable of “perfect” combustion, some of solid particles and liquid droplets found in the air. Some fuel is incompletely oxidized and therefore produces addi particles are large or dark enough to be seen as soot or Smoke. tional pollutants. Other types of fuel can also be used, for Others are so small they can be detected only with an electron example, ethanol mixtures, vegetable oils, and other fuels microscope. These particles, which come in a wide range of known in the art. sizes (“fine particles are less than 2.5 micrometers in diam 0017. In gasoline engines, in order to reduce emissions, eter and coarser particles are larger than 2.5 micrometers), modern car engines carefully control the amount of fuel they originate from many different stationary and mobile sources burn. They try to keep the air-to-fuel ratio very close to the as well as from natural sources. Fine particles (PM-2.5) result stoichiometric point, which is the calculated ideal ratio of air from fuel combustion from motor vehicles, power generation, to fuel. Theoretically, at this ratio, all of the fuel will be burned and industrial facilities, as well as from residential fireplaces using all of the oxygen in the air. The fuel mixture actually and wood stoves. Coarse particles (PM-10) are generally varies from the ideal ratio quite a bit during driving. Some emitted from sources such as vehicles traveling on unpaved times the mixture can be lean (e.g., an air-to-fuel ratio higher roads, materials handling equipment, and crushing and grind than the typical value of 14.7), and other times the mixture US 2008/01 12865 A1 May 15, 2008

can be rich (e.g., an air-to-fuel ratio lower than 14.7). These own characteristic differences from the U.S., but essentially deviations result in various air emissions. use the same types of equipment and restrict the same types of 0.018 Significant emissions of a gasoline car engine air pollutants. include: nitrogen gas (N) (air is 78% N); carbon dioxide 0022. The mobile, on-road engines, equipment, and (CO), a combustion product; and water vapor (H2O), another vehicles include, but are not limited to, passenger cars, pickup combustion product. These emissions are mostly benign to trucks, minivans, sport-utility vehicles (SUVs), buses, deliv ery trucks, semi-trucks, passenger vans, and two or three humans (although excess levels of atmospheric CO2 are wheeled motorcycles designed for on-road use. These mar believed to contribute to global warming). Gasoline engines, kets historically have lead the way in emissions control and however, also produce carbon monoxide, nitrogen oxides, continue to do so today by following regulations that dictate and unburned hydrocarbons, all of which are included in the lower levels of air pollutants. EPA's criteria pollutants (unburned hydrocarbons form part 0023 The car and truck markets are divided by weights. of the ozone formation mechanism, along with NOx). Those under 8,500 pounds Gross Vehicle Weight Rating 0019 Diesel engines also contribute to the criteria pollut (GVWR) are considered light duty vehicles. Vehicles ants. These engines use hydrocarbon fractions that auto-ig between 8,500 and 10,000 lbs GVWR that are designed for nite when compressed Sufficiently in the presence of oxygen. passenger transport are considered medium duty vehicles. In general, diesel combusting within a cylinder produce Vehicles over 8,500 lbs. GVWR that are not designed for greater amounts of particulate matter and the pollutants nitro personal use are labeled as heavy-duty vehicles. gen and sulfur oxides (NO, and SO, respectively) than does 0024 Passenger cars and light-duty vehicles were previ gasoline. Even so, diesel mixtures are generally lean, with ously regulated by vehicle weight and fuel type but will be relatively abundant amounts of oxygen present. Conse regulated in one group in future standards. Less than 1% of quently, the combustion of Smaller hydrocarbons is usually ~17 million new passenger cars and light-duty vehicles pro more complete, producing less carbon monoxide than gaso duced in the United States use diesel engines. Passenger cars line. Longer chain hydrocarbons are more difficult to burn and light-duty vehicles includes those made by manufactur completely and can result in the formation of particulate ers such as Ford, General Motors (GM). DaimlerChrysler, residues such as carbon “soot.” BMW, Honda, Hyundai, Daewoo, First Automobile Group, Toyota, Nissan, SAIC-Chevy and Subaru. 0020 Despite these drawbacks, fossil fuels are relatively 0025 Regulations on passenger cars and light-duty abundant, easy to handle, and economical. Thus, these fuels vehicles have existed for decades but have recently become will continue to represent a significant Source of mechanical much more stringent. The Tier 2 standards, phasing in from power and pollution for years to come. Moreover, the perva model year (MY) 2004-2009, require original equipment siveness of the internal combustion engine indicates how manufacturers (OEMs) to certify their fleet into certain “bins' fossil fuels will continue to be a necessary source of energy. of standards and to maintain a corporate average for NOX 0021. There are at least three markets of internal combus emissions. Vehicles under 6,000 lbs GVWR must be fully tion engines that produce air significant pollution: 1) mobile, compliant by 2007, those from 6,000-8,500 lbs and MDVs on-road engines, equipment, and vehicles 2) mobile, non must be compliant by 2009. Pollutants included in the stan road engines, equipment, and vehicles and 3) stationary or dards include: NOx, formaldehyde (HCHO), CO, PM, and "point” sources. In each of these markets, government agen non-methane organic gases. California has historically had cies and other organizations have dictated restrictions on tighter regulations than the EPA, and other states, including levels of air pollution. These restrictions have become New Jersey, New York, Vermont, Maine, and Massachusetts, increasingly stringent as the number of internal combustion have joined in California's even lower emissions levels for engines in use proliferates and more is learned about the harm new and used vehicles. Manufacturers who do not meet the caused by air pollution. The ever-tightening regulations have standards are essentially prohibited from producing their required industries to continuously research, develop, and vehicles in these markets, and are fined for ones discovered on invest in new emissions control technologies, from fuel for the market. In the aftermarket, states regulate cars and light mulations to engine redesign, to after treatment devices. duty vehicles emissions through inspection and maintenance These technologies vary in both effectiveness and cost but (I/M) programs. These programs are often created from state have become essential in order for companies to comply with implementation plans (SIPs) required in national ambient air regulations. No single emissions control technology has been quality (NAAO) non-attainment areas. Meeting both new able to remove all relevant pollutants, so multiple technolo vehicle and aftermarket standards requires the use of emis gies often have to be used together in order to enable a sion control technologies, often in parallel. particular type of vehicle or equipment to meet regulatory 0026. Historically, three-way catalytic converters have emission limits. These markets, their regulations, and the had widespread use in cars and light-duty Vehicles. Recent technologies on which they rely are described in the follow improvements in these converters (such as increased Sub ing paragraphs. The technologies, including their benefits and strate porosity, an optimized washcoat, reduced catalyst load drawbacks, are described in more detail following this sec ing, etc), have yielded incremental improvements in emis tion. While the sections focus on U.S. engines, equipment, sions control. To meet the newest set of U.S. regulations, and vehicles, other geographies have similar products and manufacturers will likely increase catalyst loading or the regulations. For instance, the EU has similar market sizes but number of substrates per vehicle. Cars in use that do not meet focuses more on selective catalytic reduction than exhaust gas inspection/maintenance standards have to replace the faulty recirculation as a diesel emission control technology, uses technology or purchase additional devices. Other emission catalytic converters in a greater percentage of its Small, off control devices include, but are not limited to, advanced injec road engines, and has a much larger percentage of diesel tion systems (such as injection timing, injection pressure, rate engines in light duty vehicles. Other geographies have their shaping, common rail injection, and electronic controls), US 2008/01 12865 A1 May 15, 2008 changed combustion chamber design (such as higher com electronic controls), pulse air systems, changed combustion pression ratios, piston geometry, and injector location), Vari chamber design (higher compression ratios, piston geometry, able valve timing, catalytic converters, and filters. and injector location), and use of catalytic converters. Limi 0027 Heavy-duty vehicles (HDV) include both private tations in motorcycles emissions control technologies are and commercial trucks and buses over 8,500 lbs GVWR. The different than those in light or heavy-duty vehicles. Motor vast majority of these engines run on diesel fuel; over 300,000 cycles focus more on the appearance, placement, and heat of are produced each year in the U.S. Manufacturers and engine aftertreatment devices, as there are fewer places to “hide' the Suppliers include, but are not limited to, Cummins, Caterpil device and the passenger is in much closer proximity to the lar, Detroit Diesel, GM, Mack/Volvo, International/Navistar, exothermic oxidation reaction. Sterling, Western Star, Kenworth, and Peterbilt. Other com 0032. The mobile, non-road engines, equipment, and panies offering other emission control technologies for the vehicles category includes, but is not limited to, engines for aftermarket include, but are not limited to, Donaldson, Engel agriculture, construction, mining, lawn and garden, personal hard, Johnson Matthey, Lubrizol, Fleetguard, Cleaire, Clean watercraft, boats, commercial ships, locomotives, aircraft, Air Partners, and Engine Control Systems. snowmobiles, off-road motorcycles, and ATVs. 0028. Heavy-duty trucks are facing rigorous emissions 0033 Small engines emit significant levels of air pollution reducing standards for PM, NOx, CO, and non-methane for their size; they are the largest single contributor to nonroad hydrocarbons (NMHC). The PM standard takes effect in HC inventories. Small engine equipment includes, but is not 2007, while NOx and NMHC standards phase-in from 2007 limited to, leaf blowers, trimmers, brush cutters, chainsaws, 2010. Similar to light duty vehicles, California, along with lawn mowers, engine riding mowers, wood splitters, Snow certain other states and metropolitan areas, has often enacted blowers, and chippers. Engine and equipment manufacturers tighter emissions standards than the EPA. For vehicles that do include, but are not limited to, John Deere, Komatsu, Honda, not meet standards, the manufacturers are prohibited from Ryobi, Electrolux (Husqvarna and Poulan, also supplies selling them. Non-compliance penalties for NOx range up to Craftsman), Fuji, Tecumseh, Stihl, American Yard Products, S12,000 per vehicle, based on size and compliance effort. and Briggs and Stratton. While other industries, such as locomotive, marine, agricul 0034. The EPA began regulating small engines in 1993 ture, and construction use highly similar engines to those in (Phase I) with standards that went into effect in 1997 and heavy-duty vehicles, the HDV market has faced the tightest continued to reduce emission levels with new standards in emission standards. Meanwhile, Some states and metropoli 2002 (Phase II). The standards divide the equipment into tan areas (such as California, New York City, and Seattle) handheld and non-handheld categories and categorize it require additional retrofits or offer incentives for retrofits to based on different engine displacements. The regulations further bring down pollution levels. These areas have certified focus on hydrocarbons and nitrogen oxides emissions. technologies that meet the approved levels and qualifications. 0035 Emissions control technologies include, but are not Examples include Donaldson's diesel oxidation catalyst muf limited to, use of a catalyst (i.e., John Deere's LE technology fler and diesel particulate filter, Cleaire's diesel oxidation and Komatsu's "Stratified Scavenged design), converting catalyst and diesel particulate filter, and Johnson Matthey's 2-stroke engines to 4-stroke, advanced injection systems (in continuously regenerating technology particulate filter. jection timing, injection pressure, rate shaping, common rail 0029. Emissions control technologies used to meet these injection, electronic controls), or changing combustion standards and for retrofits include, but are not limited to, chamber design (higher compression ratios, piston geometry, advanced injection systems (injection timing, injection pres and injector location). Sure, rate shaping, common rail injection, electronic con 0036. The recreational vehicle markets include off-high trols), exhaust gas recirculation, changes in combustion way motorcycles, Snowmobiles, and all-terrain vehicles chamber design (higher compression ratios, piston geometry, (ATVs). These are made by manufacturers and engine Sup and injector location), advanced turbocharging, ACERT, die pliers such as: Caterpillar, Cummins, Detroit Diesel, Ford sel particulate filters, NOx adsorbers, selective catalytic Power Products, GM, Honda, John Deere, Kawasaki, Mitsub reduction, conventional catalytic converters, catalytic ishi Motors, Nissan, Toyota, Yanmar, Arctic Cat, Bombardier, exhaust mufflers, and diesel oxidation catalysts. Meeting the Brunswisk, International Powercraft, Polaris, Suzuki, and 2007 standards has initiated new research and development Yamaha. on many of these emission control technologies. There has 0037. The EPA began regulating recreational vehicles been tremendous cost and effort put into determining an later than many other markets, though California had regula emissions control solution for 2007 HDVs. tions in place beforehand. EPA has phase-ins from 2006-2009 0030 Motorcycles are another type of mobile, on-road for snowmobiles, and 2006-2007 for off-highway motor vehicle and include both two and three-wheeled motorcycles cycles and ATVs. The regulated pollutants include HC, CO, designed for on-road use. Motorcycles primarily use gasoline and NOX. Emission control technologies for recreational fuel. Manufacturers include, but are not limited to: Harley vehicles include, but are not limited to, converting 2-stroke Davidson, BMW, Honda, Kawasaki, Triumph, Tianjin Gang engines to 4-stroke, advanced injection systems (injection tian, Lifan Motorcycle, and Yamaha. Regulations for on-road timing, injection pressure, rate shaping, common rail injec motorcycles were adopted in 1978 and then left unrevised tion, electronic controls), pulse air, or changing combustion through 2003, when new standards following those in Cali chamber design (higher compression ratios, piston geometry, fornia were agreed upon. Pollutants monitored in the new and injector location). standards include HC, NOx, and CO. 0038. In mining, regulations are established by the Mine 0031 Emissions control technologies for motorcycles Safety and Health Administration. Mining is often considered include, but are not limited to, conversion of 2-stroke engines one of the most taxing environments for equipment, due to the to 4-stroke, advanced injection systems (injection timing, high levels of vibration, impact, and dust. Temperature and injection pressure, rate shaping, common rail injection, and flammability are also larger concerns in mining. Diesel oxi US 2008/01 12865 A1 May 15, 2008

dation catalyst have been retrofitted on Some mining equip NOx and PM going into effect between 2004 and 2007, ment, while diesel particulate filters are becoming more com depending on engine size. Diesel marine non-recreational O boats over 30 L, including container ships, tankers, bulk 0039. In the agriculture and construction markets, the EPA carriers, and cruise ships, have NOX standards going into regulates both spark-ignition and compression-ignition effect in 2004 (Tier 1) and additional HC, PM, and CO stan engines. These can be used in tractors, forklifts, bulldozers, dards in 2007 (Tier 2). Diesel marine recreational boats, electric generators, pavers, rollers, trenchers, drill rigs, mix including yachts, cruisers, and other types of pleasure craft, ers, cranes, balers, compressors, etc. Manufacturers of have standards matching those of diesel marine non-recre engines and equipment include, but are not limited to: Agco, ational boats under 30 L displacement, but have later imple Komatsu, CNH Global, Caterpillar, Cummins, Daewoo, John mentation dates, ranging from 2006-2009 based on engine Deere & Co, Dueutz, Detroit Diesel, and Kubota. size. Gasoline and diesel boats only have regulations cur 0040. The EPA began regulating the diesel portion of these rently applying HC emissions in outboard engines, personal engines in 1994 (Tier 1) and has more recently increased the watercraft, and jetboats. Sterndrive and inboard engines are standards with Tier 2 (phased in from 2001-2006). The stan inherently cleaner and are not yet regulated. dards are slated to increase again with Tier 3 levels from 0044 Emissions control technologies are similar to those 2006-2008. The Tier 3 levels will likely require the use of used on heavy-duty vehicles and include, but are not limited emissions control devices similar to those used on heavy-duty to, using 'green terminals' when the boat is at dock, conver vehicles (such as tractor-trailers). The gasoline, liquid pro sion from 2-stroke to 4-stroke engines, water aftercooling, pane gas, or compressed natural gas (CNG) engines used in exhaust gas recirculation, diesel particulate filters, selective agriculture and construction applications have also had recent catalytic reduction, diesel oxidation catalyst, catalytic con changes in regulations. Tier 1 levels began in 2004 and match Verters, advanced fuel injection (injection timing, injection those adopted earlier by CARB: Tier 2 levels are expected to pressure, rate shaping, common rail injection, electronic con start in 2007. A voluntary program for vehicles with lower trols), advanced turbocharging, variable valve timing, and emissions than the standards exists, named "Blue Skies changing the combustion chamber design (higher compres Series. Based on engine size and fuel type, the levels of sion ratios, piston geometry, and injector location). Using particulates, carbon monoxide, nitrogen oxides, and non Smaller engines for auxiliary power (e.g., auxiliary power methane hydrocarbons all must be significantly reduced for unit, APU) also helps to control emissions. While salt water current phase-ins and for shortly forthcoming standards. and its associated pollutants and cooling effect on boats 0041 Emissions control technologies are similar to those present difficulties in aftertreatment, the APU may work well used on heavy-duty vehicles and includes, but is not limited with an aftertreatment device. to, advanced injection systems (injection timing, injection 0045. The locomotive market relies principally on diesel pressure, rate shaping, common rail injection, electronic con fuel (coal and wood-fired have limited use) and includes trols), exhaust gas recirculation, changes in combustion trains used in freight and passenger rail, line-haul, local, and chamber design (higher compression ratios, piston geometry, switchyard service. There are over 600 trains produced each and injector location), advanced turbocharging, ACERT, die year in the U.S. Manufacturers and engine Suppliers include, sel particulate filters, NOx adsorbers, selective catalytic but are not limited to, GM’s Electromotive Division, GE reduction, conventional catalytic converters, catalytic Transportation Systems, Caterpillar, Detroit Diesel, Cum exhaust mufflers, and diesel oxidation catalysts. Exhaust gas mins, MotovePower, Peoria Locomotive Works, Republic recirculation (EGR) has been problematic due to its tendency Locomotives, Trinity, Greenbrier, and CSX. to create Sulfuric acid formation in the engine's intake. It also 0046 Regulations on trains began in 2000 and largely requires cooling, which necessitates a larger radiator, and imitated those of heavy-duty vehicles. The standards include thus a larger nose on the vehicle, creating aerodynamic and levels for newly produced engines, as well as for engines that fuel economy constraints. are remanufactured (which occurs approximately ever 4-8 0042. In marine applications, engines can generally be years) and vary based on whether the engine is for Switch or divided by use of gasoline or diesel fuel, personal or commer line-haulpurposes. Tier 0 applies to engine model years (MY) cial use, or by engine size. Marine units range from personal from 1973-2001, Tier 1 to MY2002-2004, and Tier 2 to watercraft, to yachts, to ferries, to tugs and ocean-going ships. MY2005 and later. A non-compliance penalty can range up to Manufacturers and engine Suppliers include, but are not lim S25,000 per engine per day. The pollutants regulated include ited to: Bombardier (Evinrude, Johnson, Ski Doo, Rotax, etc), particulate matter, NOx, HC, CO, and smoke opacity. Caterpillar, Cummins, Detroit Diesel, GM, Isuzu, Yanmar, 0047 Emissions control technologies are similar to those Alaska Diesel, Daytona Marine, Marine Power, Atlantic used on heavy-duty vehicles and include, but are not limited Marine, Bender Shipbuilding, Bollinger Shipyards, VT Hal to, advanced injection systems (injection timing, injection ter Marine, Eastern Shipbuilding, Gladding-Hearn, JeffBoat, pressure, rate shaping, common rail injection, electronic con Main Iron Works, Master Boat, Patti Shipyard, Quality ship trols), exhaust gas recirculation, changes to combustion yards, and Verret Shipyard, MAN B&W Diesel, Wartsila, chamber design (higher compression ratios, piston geometry, Mitsubishi, Bath Iron Works, Electric Boat, Northrop Grum and injector location), selective catalytic reduction, diesel man (includes Avondale, Ingalls, and Newport News Ship oxidation catalysts, and aftercoolers, split cooling, Zeolite yards). sieves, and NOx reduction catalysts. Using a smaller, auxil 0043. The EPA regulates boats whether they are recre iary power unit is also becoming an emissions control strat ational, private, or commercial. The major category divisions egy, one which has fewer restrictions around the use of an are based on engine displacement, from recreational vehicles aftertreatment device to tankers. Diesel marine non-recreational boats under thirty 0048. The aircraft market includes all types of aircraft, liter (30 L) displacement, including fishing boats, tugboats, including planes made by Boeing, Airbus, Cessna, Gulf towboats, dredgers, and cargo vessels, have new standards for stream, and Lockheed Martin, among others. Both the EPA US 2008/01 12865 A1 May 15, 2008

and European Union follow the International Civil Aviation There are also some technologies that are currently limited in Organization's (ICAO) emissions standards. The EPA use, either by technological or commercial restrictions. adopted ICAO’s current standards for CO and NOx in gas 0053 Advanced injection systems include changes in turbine engines in 1997, having adopted their HC levels in injection timing, injection pressure, rate shaping, air-assisted 1984. In the U.S., the FAA monitors and enforces these stan fuel injection, sequential multi-point injection, common rail dards. Much of the emissions control is done through engine technologies and fuel changes. injection, resizing or moving the injector holes, and some electronic controls. In the common-rail system, a microcom 0049 Stationary sources include those sources of pollu puterized fuel pump controls the flow and timing of fuel (e.g., tion that are non-mobile. The EPA has issued rules covering over 80 categories of major industrial sources, including the Mercedes-Benz E320 uses this system). Secondary air powerplants, chemical plants, oil refineries, aerospace manu injection can promote HC and CO combustion in the mani facturers, and steel mills, as well as categories of Smaller fold. Changing the injection system can reduce a variety of Sources, such as dry cleaners, commercial sterilizers, second emissions and can also increase fuel economy; however, this ary lead Smelters, and chromium electroplating facilities. requires significant work on the engine to ensure efficiency. Power plants can use stationary diesel engines, stationary gas 0054 Exhaust gas recirculation (EGR) directs some of the turbines, and nuclear power, among other sources. Each of exhaust gases back into the intake of the engine. By mixing these sources produces different pollutants; for instance, the exhaust gases with the fresh intake air, the amount of nuclear power plants produce iodine and hydrogen, gas tur oxygen entering the engine is reduced, resulting in lower bines produceNOx, CO, SOX, CH4, and VOCs, and refineries nitrogen oxide emissions. EGR does not require regular produce gaseous vapors, CO, NOx, VOCs, CO2, CH4, and maintenance and works well in combination with high Swirl, PM. Each industry requires different control technologies to high turbulence combustion chambers. EGR also has draw reduce air emissions. backs, such as reduced fuel efficiency and engine life, greater 0050 EPA regulations cover the six criteria pollutants and demands on the vehicle's cooling system, limited to no effect the additional 188 toxic air pollutants. Specific programs on pollutants other than NOx, and it requires control algo implemented include the Acid Rain Program, designed to rithms and sensors. For these reasons, EGR is often used in reduce Sulfur emissions and the OZone Transport Commis parallel with another control technology. Companies sion’s NOx Budget Program, designed to reduce NOx emis involved in EGR technology include Doubletree Technolo sions. RECLAIM is a program established for trading NOx gies, ETC. STT Emtec, Cummins, Detroit Diesel, Mack, and and SOX credits. In addition, cap and trade programs have Volvo. been implemented in some industries and geographies, allow 0055 Optimizing the combustion chamber, or making ing companies to trade their emission credits. incremental improvements to it, is another way manufactur 0051. The technology used to control emissions from sta ers and developers are controlling emissions. Reducing the tionary sources varies widely, but examples include filters, crevice Volumes can limit trapping of unburned fuel (and thus scrubbers, sorbents, selective catalytic reduction (SCR), pre HC formation), while reducing the amount of lubricating oil cipitators, Zero-slip catalysts, catalysts for turbines, or oxida can also reduce HC formation and can limit catalyst poison tion catalysts. Some of the Suppliers of emissions control ing. Other measures include: improving the Surface finishes systems to stationary markets include: M+W Zander, Crys of cylinders and pistons, improving piston ring design and tall, Jacobs E., Takasogo, IDC, ADP, Marshall, Bechtel, material, and improving exhaust valve stem seals. Also, a Megte, Angui, Adwest, Eisenmann, Catalytic Products, LTG, “fast burn' combustion chamber can be made by: increasing Durr, Siemens. Alston. Catalyst suppliers include: Nikki, the rate of combustion, reducing the spark advance, adding a BASF, Cormetech, W.R. Grace, Johnson Matthey, UOP, and dilutent to the air-fuel mixture, and/or increasing turbulence Sud Chemie. in the chamber. While optimizing the combustion chamber 0052. Due to the importance of improving air quality and can lead to reduced emissions, it is another technology that complying with relevant laws and regulations, Substantial requires reworking of the engine, which can be an expensive time, money, and effort have been invested in technologies process. capable of reducing emissions. Three general areas of tech 0056 Variable valve timing involves calibrating the nology include, a) engine improvements, b) fuel improve engine valves to open and close for maximum fuel and engine ments, and c) after-treatments. These approaches are typi efficiency. Often, a sensor is used to detect the engine's speed cally not mutually exclusive or stand-alone solutions. Engine and to adjust the valve openings and closings accordingly. improvements include, but are not limited to. Such technolo This technology can increase engine torque and horsepower gies as: advanced injection systems, exhaust gas recircula and can improve Swirl and intake charge Velocity, thus tion, electronic sensors and fuel controls, combustion cham improving the efficiency of combustion. Variable valve tech ber designs, advanced turbocharging, and variable valve nology does not reduce emissions as much as some other timing. Fuel improvements include, but are not limited to, technologies and often leads to reductions in fuel efficiency. Such formulations as: high cetane, low aromatics, low Sulfur 0057 Reformulating or using different fuels is another fuel, fuel borne catalysts, liquefied petroleum gas (LPG), emissions control technique, as some fuels naturally pollute oxygenation of fuels, compressed natural gas (CNG) and more than others, while some tend to poison the catalysts that biodiesels. After-treatment technologies include, but are not would otherwise clean the exhaust air. For instance, the shift limited to: catalytic converters (2, 3, and 4-way), particulate from leaded to unleaded fuel in the U.S. greatly decreased traps, selective catalytic reduction, NOx adsorbers, HC lead emissions. Lowering the Sulfur content in fuel reduces adsorbers, NOx reduction catalysts, and many others. Some SOX emissions and increases the efficiency of many catalytic systems incorporate various pieces of these and other tech converters, as Sulfur can poison catalysts. Another type of nologies: ACERT by Caterpillar or catalyzed diesel particu fuel, natural gas, typically produces less particulate pollution late traps are examples of combination systems and devices. than diesel fuel and also can reduce NOx and combustion US 2008/01 12865 A1 May 15, 2008

noise. Conversely, natural gas also can increase vehicle these traps can become clogged with PM, Soot, and ash and weight (due to the need for high pressure tanks) and has catalyzed versions can be poisoned. They also add cost and refueling limitations. weight to vehicles. 0058. Using an aftertreatment device—equipment that is 0064 Diesel particulate traps can use a number of differ used after the fuel is combusted is very common in certain ent types of filters, including: ceramic monolithic cell fiber industries affected by emissions control regulations. One (Corning, NGK), fiber-wound filter (3M), knitted fiber example of an aftertreatment device is a catalytic converter. (BUCK), woven fiber (HUG,3M), sintered metal fiber (SHW, Catalytic converters can vary widely and can have different HJS) or filter paper, among others. Suppliers of these devices functions, but the general description is a device that treats and their related technologies include, but are not limited to, exhaust with the use of catalysts. The composition of the Donaldson, Engelhard, Johnson Matthey, HJS, Eminos, Substrates and the catalysts that are on it have changed Deutz, Corning, ETG, Paas, and Engine Control Systems. 0065. Selective catalytic reduction (SCR) is another throughout the years, as has the placement and the number of example of an aftertreatment system. In this technology, a COnVerters. chemical capable of acting as a reducing agent, Such as urea, 0059 A two-way catalytic converter performs oxidation is added before the exhaust reaches the catalyst chamber. of gas-phase pollution, such as the oxidation of HC and CO to Urea hydrolyzes to form ammonia. The ammonia then reacts CO, and H.O. Diesel oxidation catalysts (DOCs) are another with the NOx of the exhaust gas to yield N gas, thereby type of two-way catalytic converter used with diesel engines. decreasing NOx emissions. The ammonia may be directly While these converters are effective at controlling HC and CO injected or be held in the form of solid urea, urea solution or and require little maintenance, they can increase NOx emis in crystalline form. An oxidation catalyst is often used in sions and are sensitive to Sulfur. parallel with SCR to reduce CO and HC. Unfortunately, while 0060 A three-way catalytic converter performs both oxi SCR is effective in reducing NOx and has low catalyst dete dation (conversion of CO and HC to CO, and HO) and rioration with good fuel economy, it requires an additional reduction (conversion of NOx to N gas) reactions. Since the tank on the vehicle and an infrastructure for refilling the tank. 1970s, three-way catalytic converters have reduced vehicle It is also dependent on end user compliance; companies and emissions. Further performance improvements by these drivers are required to refill the tank in order to maintain the devices are limited by a number of factors, such as the tem emissions control. Suppliers of SCR or its components perature range and Surface area of their substrates and by include, but are not limited to, Engelhard, Johnson Matthey, catalyst poisoning. To meet increasingly stringent regula Miratech Corporation, McDermott, ICT, Sud Chemie, SK tions, some cars require multiple catalytic converters. Catalysts, and PE Systems. While only used in the U.S. on a 0061. A four-way catalytic converter performs oxidation limited basis, SCR is expected to be widely used in Europe to and reduction reactions, and traps particulates to burn them reduce emissions, particularly in the heavy duty truck market. off (regeneration can occur in active or passive mode). 0.066 NOx adsorbers are materials that store NOx under 0062 Suppliers of catalytic converters and their associ lean conditions and release and catalytically reduce it under ated parts include, but are not limited to, Corning, NGK, fuel rich conditions (typically every few minutes). This tech Denso, Ibiden, Emitec, Johnson Matthey, Engelhard, Cata nology can work in both gas and diesel applications, though lytic Solutions, Delphi, Umicore, 3M, Schwäbische Hütten gas provides a better fuel rich, high temperature environment. Werke GmbH (SHW); Hermann J. Schulte (HJS), Clean Die NOx adsorbers reduce the levels of HC, NOx, and CO, but sel Technology, Cleaire, Clean Air Systems, ArvinMeritor, have little to no effect on PM. They can function under a wide Tenneco, Eberspacher, Faurecia, Donaldson, and Fleetguard. range of temperatures. Conversely, NOx adsorbing capacity 0063 Particulate traps or filters are another type of after decreases based on temperature, requires engine controls and treatment device commonly used in diesel applications, as sensors, and is functionally hindered or disabled by the sulfur diesel fuel generates more particulate matter than gasoline or content in fuel. In diesel applications, there are additional some alternative fuels. In a diesel particulate trap (DPT), constraints, including the quantity of oxygen present in the particles in the exhaust stream pass through a filter that col exhaust, the HC utilization rate, the temperature range, and lects them. The removal of particulate matter that is collected Smoke or particulate formation. on the trap is referred to as "regeneration' and can occur in 0067. ANOx reduction catalyst can also be used to control multiple ways. One method uses external heaters to raise the emissions by 1) actively injecting reductant into the system temperature of the filter to a level necessary for the PM to ahead of the catalyst and/or 2) using a washcoat with a Zeolite “burn off.” Another method releases small amounts of diesel that adsorbs HC, thus creating an oxidizing region conducive fuel in the exhaust stream. When the fuel particles come in to reducing NOx. While this technology can reduce NOx and contact with the filter, the fuel burns off at an elevated tem PM, it is more expensive than many other technologies and perature. This higher temperature burns the PM off the filter can lead to poor fuel economy or Sulfate particulates. as well. Yet another means is to use fuel borne catalysts to 0068 HC adsorbers are designed to trap VOCs while the facilitate regeneration. In another approach, called a “cata catalyst is cold and then release them once the catalyst is lyzed diesel particulate trap, a catalyst is applied directly to heated. This can be done by 1) coating the adsorber directly the filter itself, which reduces the temperature necessary for onto the catalytic converter substrate, which allows for mini the PM to burn off. Finally, an oxidation catalyst can be used mal changes but less control. 2) locating the adsorber in a in front of the filter to facilitate burn off of the PM. Johnson separate, but connected exhaust pipe before the catalytic con Matthey's Continuously Regenerating Trap (CRT) is such a Verter and having the air switch channels once the converteris system. Diesel particulate traps can reduce PM by as much as heated, and/or 3) placing the adsorber after the catalyst. The 85% in Some applications. Traps utilizing a catalyst can also last two options require a cleaning option for the adsorber. reduce other pollutants besides PM (e.g., HC, CO, and PM) While this technology reduces cold start emissions, it is dif with use of a catalyst (as mentioned earlier). Conversely, ficult to control and adds cost. US 2008/01 12865 A1 May 15, 2008

0069. Since emissions have proven difficult to control, form nitrogen. When an NO or NO molecule contacts the emissions control technologies are often combined in a sys catalyst, the catalyst facilitates removal of nitrogen from the tem. Examples of combination systems include: a DeNOx molecule, freeing oxygen in the form of O. Nitrogen atoms and DPT (such as HJS SCRT system), a catalytic converter adhering to the catalyst then react to form Nagas: 2NO->N+ placed in the muffler, SCR integrated with the muffler, or a O and 2NO=>N+2O. catalyzed diesel particulate filter. 0078. The carbon monoxide, unburned hydrocarbons, and 0070 ACERT is another example of a system incorporat particulate matter can be further oxidized to form nonpollut ing multiple emissions control technologies. ACERT, from ants. For example, carbon monoxide is processed as shown: Caterpillar, targets four areas—intake air handling, combus 2CO+O=>2CO. tion, electronics, and exhaust aftertreament. Key components (0079. The overall result of the catalytic converter is to include single and series turbocharging for cooling intake air; complete the combustion of fuel into nonpollutants. variable valve actuation for improving fuel burns; electronic 0080 Conventional catalytic converters have a number of multiplexing for integrating computer control; and catalytic limitations on their effectiveness of eliminating pollutants. conversion for reducing tailpipe particulate emissions. Work For example, if they are located too close to an engine, they ing in concert, these Subsystems allow the company to can crack from overheating or a quick change in temperature. increase fuel savings. A significant weakness of this technol As such, the filters of the conventional catalytic converters ogy is the high Volume of catalyst needed. cannot be placed immediately next to or inside an engine 0071. There are many other emissions control technolo exhaust manifold, which is an optimal location to take advan gies, some of which are not yet technically feasible. tage of the in situ high temperatures before the temperature decreases due to radiant cooling from the high thermal con Catalytic Converters ducting properties of exhaust pipe material. Engine vibration 0072 The concerns of pollution caused partly by the auto and the quick change in temperatures that exist near and mobile led to the Clean Air Act of 1970 which required 90 within the exhaust manifold would cause conventional filter percent reductions in auto exhaust. The mandatory reduction material to fatigue and dramatically shorten the life of the was considered controversial by Some but generally recog filters. In addition, some catalysts applied to conventional nized as an advance for clean air and better health. filters work less efficiently or even cease to function at high 0073. The automobile industry initially offered resistance temperatures, i.e., above 500 degrees Celsius. Accordingly, to the new proposed regulations. Part of the resistance may the conventional catalytic converter filters are usually placed have stemmed from the industries development of improved in the exhaust path in a location away from the engine. fuels. From the mid 1920's until the mid 1980's, motor gaso line fuel contained an additive, tetraethyllead (TEL). TEL Structures of Catalytic Converter and Particulate Filter improved fuel performance by preventing pre-ignition in the cylinders of the engine. Pre-ignition results when the fuel/air I0081. The components and materials of a catalytic con mixture ignites prematurely in the combustion chamber of an verter are shown schematically in FIGS. 4a and 4b. The engine. This results in damage to the engine and efficiency catalyst substrate is held within the converter shell (also and power reducing caused by knocking. called a canister) using packaging mat (most often made of ceramic fibers). The converter is connected to the vehicle's 0074 To attain the reduced emission standards set by the exhaust system through the end cones, which can be either government, engineers invented the catalytic converter. The welded to the shell or beformed as one part together with the catalytic converter was added to vehicle exhaust systems shell, depending on converter packaging technology. The starting about 1976. The catalytic converter was effective in other components shown in the schematic-end seals and/or reducing emissions to a certain degree. However, the com steel Support rings—are optional; they are usually not present mon gasoline formulations containing TEL interfered with in modern passenger car converters, but may be required in the function of the catalytic converter. Because the TEL in the more demanding applications. Such as close-coupled convert fuel poisoned the metal catalysts of the catalytic converter, ers, large converters for heavy-duty engines, or diesel particu TEL was eventually removed from fuel. late filters. Catalytic converters, especially those in gasoline 0075 While many people may be aware that many applications, can be also equipped with steel heat shields (not vehicles have a catalytic converter, it is generally an unappre shown in the schematic) to protect adjacent vehicle compo ciated piece of technology. The purpose of the catalytic con nents from exposure to excessive temperatures. Verter is to convert, or change, exhaust gases that are pollut I0082 Generally, a catalytic converter is composed of at ants to less harmful compounds, such as nitrogen (N, which least five main components: 1) a Substrate; 2) a catalytic makes up about 78% of the atmosphere), water (HO), and coating; 3) a wash-coat; 4) a matting; and 5) a canister. A carbon dioxide (CO, a product of photosynthesis in plants). general catalytic converter is shown in Figure X. In certain 0076. The catalytic converter is used to facilitate the con applications, as discussed in more detail below, the catalytic version of the unwanted pollutants to relatively harmless coating is optional. molecules such as N., H2O, and CO. Basically, the catalytic converter provides a surface on which the pollutants are con verted into the relatively harmless products. A catalyst allows Substrate the reaction to proceed faster (or at a lower temperature) by I0083. The substrate is a solid surface on which the pollut lowering the activation energy required. However, a catalyst ants can be converted to the nonpollutants. Physically, a Sub is not used up in the reaction and can be used again (unless the strate provides the interface for several molecular species, in catalyst is poisoned). any physical state Such as solid, liquid, or gas, to react with 0077. Typical pollutants in exhaust include nitrogen each other. The Substrate generally has a large Surface area to oxides (NOx), unburned hydrocarbons, carbon monoxide, provide a large area on which the pollutants can be converted and particulate matter. The nitrogen oxides can be reduced to to nonpollutants. US 2008/01 12865 A1 May 15, 2008

0084. Over the past decades, many different materials and countless materials. Catalysts are widely used in chemical designs have been tested to act as the Substrate for chemical and petrochemical processing to facilitate reactions which reactions. For example, main physical structures include hon otherwise are too slow, or which require high temperatures to eycomb monoliths and beads. (See FIG. 1). The honeycomb yield good efficiencies. Catalysts are also used to convert structure contains numerous channels, usually running paral harmful components of engine exhaust gases, such as hydro lel to each other along the length of the substrate. The sub carbons and carbon monoxide, into harmless Substances, strate has channels that run the length of the substrate. The Such as carbon dioxide and water vapor. width of channels varies, often depending on the Substrate material and applications for which it is used. These channels I0089 Catalysts are substances that have the ability to allow the exhaust gas to flow from the engine through the accelerate certain chemical reactions between exhaust gas catalytic converter and out through exhaust pipe. While the components. In emission control catalysis, Solid catalysts are exhaust gas flows through the channels of the Substrate, the used to catalyze gas phase reactions. The catalytic effect and pollutant molecules are converted into nonpollutant mol the observed reaction rates are maximized by providing good ecules via chemical reactions and physical changes. contact between the gas phase and the Solid catalyst. In cata 0085. In the bead structure, the substrate is made of a lytic reactors, this is usually realized by providing high cata collection of small beads (similar to putting a bunch of jelly lytic Surface area through finely dispersing the catalyst on beans in a tube). The exhaust can flow around the beads high specific Surface area carrier (Support). (through the channels and crevices). The pollutants are con 0090 The catalytic coating is added to the substrate after Verted to nonpollutants as the exhaust gas hits the beads. The the substrate is formed. The coating forms a layer on the bead structure was one of the early attempts to maximize the Surface of the Substrate, the layer containing the catalyst. surface area of substrate to which the exhaust molecules were Different types of catalysts are needed depending, for exposed. example, on the chemical reaction, application needed, tem 0.086 A number of different materials have been used as the substrate. These include ceramic, Fiber Reinforced perature conditions, economic factors, etc. A number of metal Ceramic Matrix Composites (FRCMC), foam, powder catalysts are known in the art. For example, the most com ceramic, nanocomposite, metals, and fiber mat-type Sub monly used are platinum, palladium and rhodium. Significant strates. The most commonly used is a ceramic called cordi research has been done to develop new catalysts. erite, which is produced by Corning. Cordierite is a ceramic 0091. The rate of chemical reactions, including catalytic formed from refractory powders. FRCMC is an open celled reactions, generally increases with temperature. A strong foam wherein catalyst is disposed on the walls of the cells, the dependency of conversion efficiency ontemperature is a char foam being disposed within a catalytic chamber Such that acteristic feature of all emission control catalysts. The con exhaust gas must pass through a cell path of the foam to exit. version, near-Zero at low temperatures, increases slowly at Foams are solids containing numerous pores that are formed first and then more rapidly, to reach a plateau at high gas by bubbles from gas and burned-off voids. Powder ceramic temperatures. When discussing combustion reactions, the substrates are different than cordierite and related ceramics in term light-off temperature is commonly used to characterize that the powder ceramic is formed from sintered ceramic this behavior. The catalyst light-off is the minimum tempera powders. Nanocomposites are materials that use nano-pow ture necessary to initiate the catalytic reaction. Due to the ders and/or nano-fibers. Metals can also be used as a Sub gradual increase of the reaction rate, the above definition is strate. Generally, thin sheets of corrugated metal foil. Such as not very precise. By a more precise definition, the light-off steel, are rolled into a honeycomb-like structure. Fiber mat temperature is the temperature at which conversion reaches type Substrates are materials that are woven on a small scale. 50%. Thattemperature is frequently denoted Tso. When com Certain fiber mat-type substrates utilize NEXTEL fibers, pro paring activities of different catalysts, the most active catalyst duced by 3M. Additionally, “two-dimensional non-woven will be characterized by the lowest light-off temperature for a fibrous composites have also been tried where honeycomb given reaction. structures were formed using rolled up pleating and/or cor 0092. In some catalyst systems, increasing the tempera rugation. For example, see U.S. Pat. Nos. 4.894,070; 5,196, ture may increase the conversion efficiency only up to a 120; and 6,444,006 B1. certain point, as illustrated by the dashed line (B) in FIG. 4. Further temperature increase, despite increasing reaction Catalytic Coating rates, causes a decrease in the catalyst conversion efficiency. 0087. The third component of current catalytic converters The declining efficiency is usually explained by other com is a catalytic coating. As the name implies, the catalytic coat peting reactions which deplete the concentrations of reactants ing is the component which actually catalyzes the conversion or by thermodynamic reaction equilibrium constrains. of pollutants to non-pollutants. 0093. The temperature range corresponding to the high 0088 A catalyst is usually defined as a substance which conversion efficiency is frequently called the catalyst tem influences the rate of a chemical reaction but is not one of the perature window. This type of conversion curve is typical for original reactants or final products, i.e., it is not consumed or selective catalytic processes. Good examples include selec altered in the reaction. In several known catalytic reaction tive reduction of NO by hydrocarbons or ammonia. mechanisms, the catalyst forms intermediate compounds 0094. Another important variable influencing the conver with reactants but is recovered in the course of the reaction. sion efficiency is the size of the reactor. The gas flow rate Many other catalytic processes are not explained fully or through a catalytic reactor is commonly expressed, relative to understood in their entirety. Neither are the principles gov the size of the reactor, as space velocity (SV). The space erning the selection and preparation of catalysts for specific Velocity is defined as the Volume of gas, measured at Standard purposes. Many of the developments in this field are achieved conditions (STP), per unit time per unit volume of the reactor, through elaborate exploration programs involving trials of as follows: (3)SV=V/V, where V is the volumetric gas flow US 2008/01 12865 A1 May 15, 2008 rate at STP m/h;V, is the reactor volume, m, and SV has the dried and calcined at high temperatures. The quality of the dimension of reciprocal time which is commonly expressed catalyst washcoat can significantly influence the performance in 1/h or h". and durability of the finished catalyst. Since the noble metal is 0095. In various catalytic emission control applications, Subsequently applied to the washcoated parts by impregna the space velocities range from 10,000 l/h to 300,000 l/h. tion, i.e., “soaking the washcoat porosity with the catalyst Space velocities for monolithic reactors are calculated on the solution, the washcoatloading will determine the noble metal basis of their outside dimensions, e.g., diameter and length of catalyst loading in the finished product. Therefore, it is a cylindrical ceramic catalyst Substrate. Since this method extremely important that the washcoating process produces a does not take into account the geometric Surface area of the very repeatable and uniform washcoat layer. The details on Substrate, cell density, wall thickness, or catalyst loading, it is the washcoating process and its parameters are guarded as not always appropriate for catalyst comparisons. Neverthe trade secrets by all catalyst makers. less, it is a commonly used and widely accepted industry standard. Canister 0096. Typical platinum loadings infilters used for off-road 0102 The Substrate is packaged into a canister, e.g., a steel engines through the 1990's were between 35 and 50 g/ft. shell, to form a catalytic converter. The canister performs a These filters, installed on relatively high polluting engines, number of functions. It holds the catalyzed substrate and required minimum temperatures of nearly 400° C. for regen protects the substrate from the external environment. Addi eration. Later, when catalyzed filters were applied to much tionally, the canister forces exhaust gas to flow through and/or cleaner urban bus and other highway vehicle engines, it was over the catalyzed substrate. found that they were able to regenerate at much lower tem 0103) The catalyzed substrate can be also packaged inside peratures. However, higher platinum loadings were needed to mufflers, which are then referred to as “catalyst mufflers' or Support the low temperature regeneration. Filters used in “catalytic mufflers.” In this case, one steel canister holds both clean engine, low temperature applications have typically the catalyst and the noise attenuation components, such as platinum loadings of 50-75 g/ft. baffles and perforated tubing. Catalyst mufflers can offer Wash Coat more space saving design compared to the combination of a catalytic converter and a muffler. 0097. In most cases, the catalytic coating includes a wash 0104. The catalyzed substrate is usually placed inside the coat as a fourth component. The washcoat is applied to the canister having a configuration made according to one of surface of the substrate, thereby increasing surface area of the several methods, including: clamshell, tourniquet, shoebox, substrate. The washcoat also provides a surface to which the stuffing, and Swaging, as shown in FIG. 36. catalyst adheres. The metal catalyst may be impregnated on this porous, high Surface area layer of inorganic carrier, (i.e., Matting washcoat the term “catalyst Support' may be used to denote the ceramic/metallic Substrate, as well as the carrier/washcoat 0105. In addition to the canister, a matting material is often material). used to package the catalytic Substrate in the canister. The 0098. A number of substances can be used as a washcoat. packaging mats, usually made of ceramic fibers can be used to Substances which are widely used for catalyst carriers protect the substrate and to distribute evenly the pressure from include activated aluminum oxide and silicone oxide (silica). the shell. The mats often include vermiculite, which expands 0099. The washcoat is a porous, high surface area layer at high temperatures, thus compensating for the thermal bonded to the surface of the support. Its exact role, which is expansion of the shell and providing adequate holding force certainly very complex, is not clearly understood or under all operating conditions. explained. The main function of the washcoat is to provide 0106 For example, ceramic monoliths are wrapped in a very high surface area, which is needed for the dispersion of special packaging material which holds them securely in the catalytic metals. Additionally, the washcoat can physically steel housing, uniformly distributing pressure and preventing separate and prevent undesired reactions between compo cracking. Ceramic fiber mats are most commonly used for nents of a complex catalytic system. packaging of catalytic converters for both gasoline and diesel 0100 Washcoat materials include inorganic base metal applications. These packaging mats can be classified as fol oxides such as Al-O (aluminum oxide or alumina), SiO, lows: intumescent (heat-expandable) mats; conventional TiO, CeO2, ZrO. V.O.s, LaO and Zeolites. Some of them (high Vermiculite); reduced Vermiculite; non-intumescent are used as catalyst carriers. Others are added to the washcoat mats; or hybrid mats. as promoters or stabilizers. Still others exhibit catalytic activ ity of their own. Good washcoat materials are characterized Heat Insulation by high specific Surface area and thermal stability. The spe 0107. In many applications, the catalytic converter must cific Surface area is determined by nitrogen adsorption mea be heat insulated to avoid damage to Surrounding vehicle Surement technique in conjunction with mathematical mod components (e.g., plastic parts, fluidhoses) or in converters eling known as the BET (Brunauer, Emmet, and Teller) mounted closer the engine—to prevent an increase of engine method. Thermal stability is evaluated by exposing samples compartment temperature. One of the methods of converter of given material to high temperatures in a controlled atmo thermal management is to employ a steel heat shield posi sphere, usually in the presence of oxygen and water vapor. tioned around the converter body. An alternative method is to The loss of BET surface area, which is remeasured at different provide an insulation layer inside the shell by either (1) time intervals during the test, indicates the degree of thermal increasing the thickness of the mounting mat, or (2) providing deterioration of the tested material. an additional layer of dedicated, low thermal conductivity 0101 The washcoat can be applied to the catalyst support insulation. While heat shields have been traditionally used in from a water based slurry. The wet washcoated parts are then the underfloor location, it has been suggested that increased US 2008/01 12865 A1 May 15, 2008

mat thickness offers the best solution for converters installed sufficiently high, the ash may eventually sinter to the filter or in the engine compartment (Said Zidat and Michael Parmen even react with the filter resulting in partial melting. tier, “Heat Insulation Methods for Manifold Mounted Con 0113. It would be considered an advancement in the art to verters.” Delphi Automotive Systems, Technical Centre Lux obtaina filter which offers improved resistance to melting and embourg, SAE Technical Paper Series 2000-01-0215). One thermal shock damage so that the filter not only survives the of the advantages of using thicker mat rather than the heat numerous controlled regenerations over its lifetime, but also shield is the lower average mattemperature, which minimizes the much less frequent but more severe uncontrolled regen the risk of destroying Vermiculite mats in close-coupledgaso erations. line engine applications. Continuous Regeneration Trap Particulate Trap 0114. One conventional method for catalytic conversion is 0108. Another device for removing pollutants from an a diesel particulate trap (“DPT). A DPT is a filter that collects exhaust gas is a particulate trap. A common particulate trap particulate matter in the exhaust. The collected particulate used on diesel engines is a diesel particulate trap (DPT). A matter must then be burned off before the filter becomes main purpose of a particulate trap is to filter and trap particu clogged. Burning off the particulate matter is referred to as late matter of various sizes from a stream of fluid, such as an “regeneration.” Several conventional methods exist for regen exhaust gas flow. The effectiveness of a particulate filter is eration of DPTs. First, an application of precious metal cata generally measured in its ability of filtering PM of different lysts or base-metal catalyst to the surface of the filter can size, e.g., PM-2.5 and PM-10. reduce the temperature needed for oxidation of particulate 0109 Diesel traps are relatively effective at removing car matter. Second, the filter can be preceded with a chamber bon soot from the exhaust of diesel engines. The most widely containing oxidation catalyst that creates NO, which helps to used diesel trap is the wall-flow filter which filters the diesel burn off particulate matter. Third, the system can utilize fuel exhaust by capturing the soot on the porous walls of the filter born catalysts. Finally, external source of heat may be body. The wall-flow filter is designed to provide for nearly employed, wherein soot burns at 550 degrees Celsius without complete filtration of soot without significantly hindering the catalysts or approximately 260 degrees Celsius with precious exhaust flow. metal catalysts. Regeneration leaves behindash residue as the 0110. As the layer of soot collects on the surfaces of the carbon burns, requiring constant maintenance to clean the inlet channels of the filter, the lower permeability of the soot filter. layer causes a pressure drop across the filter and a gradual rise 0115 Yet another conventional method utilizes diesel oxi in the back pressure of the filter against the engine, causing dation catalysts (“DOCs'). DOCs are catalytic converters the engine to work harder, thus affecting engine operating that oxidize CO and hydrocarbons. Hydrocarbon activity efficiency. Eventually, the pressure drop becomes unaccept extends to the polynuclear aromatic hydrocarbons (“PAHs) able and regeneration of the filter becomes necessary. In and the soluble organic fraction (“SOF) of particulate mat conventional systems, the regeneration process involves heat ter. Catalyst formulations have been developed that selec ing the filter to initiate combustion of the carbon soot. In tively oxidize the SOF while minimizing oxidation of sulfur certain circumstances, the regeneration is accomplished dioxide or nitric oxide. However, DOCs may produce sulfuric under controlled conditions of engine management whereby acid and increase the emission of NO. a slow burn is initiated and lasts a number of minutes, during 0116. The function of the catalyst in the catalyzed diesel which the temperature in the filter rises from about 400-600° particulate filter (CDPF) is to lower the soot combustion C. to a maximum of about 800-1000° C. temperature to facilitate regeneration of the filter by oxidation 0111. In certain applications, the highest temperatures of diesel particulate matter (DPM) under exhaust tempera during regeneration tend to occur near the exit end of the filter tures experienced during regular operation of the engine/ due to the cumulative effects of the wave of soot combustion vehicle, typically in the 300-400° C. range. In the absence of that progresses from the entrance face to the exit face of the the catalyst, DPM can be oxidized at appreciable rates at filter as the exhaust flow carries the combustion heat down the temperatures in excess of 500° C., which are rarely seen in filter. Under certain circumstances, a so-called “uncontrolled diesel engines during real-life operation. Reported Substrates regeneration' can occur when the onset of combustion coin used in these catalyst applications include cordierite and sili cides with, or is immediately followed by, high oxygen con con carbide wall-flow monoliths, wire mesh, ceramic foams, tent and low flow rates in the exhaust gas (such as engine ceramic fiber media, and more. The most common type of a idling conditions). During an uncontrolled regeneration, the CDPF is the catalyzed ceramic wall-flow monolith. combustion of the Soot may produce temperature spikes 0117 Catalyzed ceramic traps were developed in early within the filter which can thermally shock and crack, or even 1980's. Their first applications included diesel powered cars melt, the filter. The most common temperature gradients and, later, underground mining machinery. Catalyzed filters observed are radial temperature gradients where the tempera were commercially introduced for Mercedes cars sold in ture of the center of the filter is hotter than the rest of the California in 1985. Mercedes models 300SD and 300D with Substrate and axial temperature gradients where the exit end turbocharged engines were equipped with 5.66" diameterx6" of the filter is hotter than the rest of the substrate. filters fitted between the engine and the turbocharger. 0112. In addition to capturing the carbon soot, the filter 0118. The use of diesel traps on cars was later abandoned, also traps metal oxide 'ash' particles that are carried by the due to Such issues as insufficient durability, increased pres exhaust gas. Usually, these ash deposits are derived from Sure drop, and filter clogging. Today, even though not all of unburnt lubrication oil that accompanies the exhaust gas these problems have been solved, catalyzed ceramic traps under certain conditions. These particles are not combustible remain one of the most important diesel filter technologies. and, therefore, are not removed during regeneration. How CDPFs are increasingly used in a number of heavy-duty ever, if temperatures during uncontrolled regenerations are applications, such as urban buses and municipal diesel trucks. US 2008/01 12865 A1 May 15, 2008

For a number of years, limited quantities of catalyzed filters cations, however, is created by the soot deposit. In practical have been also used in underground mining (North America applications, the pressure drop of the clean wall-flow filter and Australia) and in certain stationary engine applications. can be in the range of 1 to 2 kPa, while a loaded filter pressure 0119 Catalyzed ceramic filters are commercially avail drop of 10 kPa can be considered in certain circumstances low able for a number of highway, off-road, and stationary engine to moderate. applications as both OEM and aftermarket (retrofit) product. 0.124. The total pressure drop of the particulate loaded The list of suppliers includes Engelhard, OMG dimc2, as well filter, can be divided into the following four components: as several Smaller emission control manufacturers who spe pressure drop due to Sudden contraction and expansion at the cialize primarily in the off-road markets. inlet and outlet from the filter; pressure drop due to channel 0120. The main component of conventional filters is a wall friction; pressure drop due to permeability of particulate ceramic (typically cordierite or SiC) wall-flow monolith. The layer; and pressure drop due to wall permeability. porous walls of the monolith are coated with an active cata 0.125 Pressure drop due to sudden contraction and expan lyst. As the diesel exhaust aerosol permeates through the sion at the inlet and outlet from the filter is similar to the same walls, the soot particles are deposited within the wall pore component in the clean filter, except that the effective channel network, as well as over the inlet channel surface. The catalyst size (hydraulic diameter) is now Smaller due to the soot layer, facilitates DPM oxidation by the oxygen present in exhaust resulting in more gas contraction. gaS. 0.126 Pressure drop due to channel wall friction also increases relative to the clean filter scenario, due to the Pressure Drop decrease in the channel hydraulic diameter. With thick soot 0121 The flow of exhaust gas through a conventional cata layers, APchannel can become a very significant contributor lytic converter creates a Substantial amount of backpressure. to the total pressure drop. The backpressure buildup in a catalytic converter is an impor I0127 Pressure drop due to permeability of particulate tant attribute to catalytic converter success. If the catalytic layer (APparticulate) is can be a significant contributor to the converter is partially or wholly clogged, it will create a total pressure drop. restriction in the exhaust system. The subsequent buildup of I0128 Pressure drop due to wall permeability (APwall) is backpressure will cause a drastic drop in engine performance now also higher than in the clean filter, because the wall pores (e.g., horsepower and torque) and fuel economy, and may are partly filled with soot. The increase in APwall that can be even cause the engine to stall after it starts if the blockage is attributed to the initial soot loading phase in the pores is severe. Conventional attempts to reduce pollutant emissions represented by API in FIG. 23. are very expensive, due to both the cost of materials and I0129. The total pressure drop can be expressed as follows: retrofitting or manufacturing an original engine with the AP=APin?out+APchannel-i-APparticulate+APwall appropriate filter. 0.130 Mathematical modeling of the pressure drop in soot 0122 High filtration efficiencies of wall-flow filters are loaded diesel filters becomes a complex and difficult task. obtained at the expense of relatively high pressure drop which Important properties of Soot. Such as the permeability and increases with the filter soot load. Initially, the filter is clean. packing density, depend on the application, engine operating As the particulate start depositing within the pores in mono conditions, and other parameters. There is an ongoing effort lith walls (depth filtration), the pressure drop starts increasing to simulate pressure drop in wall-flow filters and increasingly with time in a non-linear manner. This phase is called the more Sophisticated models are being developed. Predicting initial loading phase, during which pore attributes like per the actual soot loading may require a theoretical model of the meability and filter porosity continuously change due to the regeneration process itself. increasing Soot deposit inside the pore network. After the filtration capacity of the pores becomes saturated, soot starts Types of Catalytic Converters and Particulate Filters depositing as a layer inside the inlet monolith channels (cake filtration phase). A linear increase in pressure drop with time I0131 Catalytic converters can be classified based on a (and with soot load) is observed during this period. One number of factors including: a) the type of engine on which property that changes is the thickness of the Soot layer. Some the converter is used, b) its location relative to the engine, c) authors also distinguish an intermediate short transition the number and type of catalysts used in the converter, and d) phase, from the moment the particulates start depositing on the type and structure of the substrate used. In addition each the channel surface until the soot layer is fully established of these catalytic converters are often used in conjunction (Tan, J. C., et al., 1996, “A Study on the Regeneration Process with other emission-control devices, such as CRT, EGR, in Diesel Particulate Traps Using a Copper Fuel Additive'. SCR, ACERT, and other devices and methods. SAE 960136; Versaevel, P., et al., 2000, “Some Empirical Observations on Diesel Particulate Filter Modeling and Com Engine parison Between Simulations and Experiments', SAE 2000 I0132 Catalytic converters are used on at least two types of 01-0477). engines: gasoline and diesel. Within these two general 0123 Pressure drop modeling in clean filter substrates has classes, there are numerous types of specific gasoline and been done. Relatively simple models that have been devel diesel engines. For example, gasoline and diesel engines are oped show excellent agreement with experimental results manufactured having varying displacements and horsepower. (Masoudi, M., et al., 2000, "Predicting Pressure Drop of Certain engines are equipped with a turbocharger and/or an Wall-Flow Diesel Particulate Filters. Theory and Experi intercooler. Most car and truck engines are water-cooled, ment, SAE 2000-01-0184: Masoudi, M., et al., 2001, “Vali while many motorcycle engines are air-cooled. Certain utili dation of a Model and Development of a Simulator for Pre ties require high available horsepower, while others maxi dicting the Pressure Drop of Diesel Particulate Filters.” SAE mize fuel economy. All of these variables, in addition to 2001-01-0911). Most of the filter pressure drop in real appli others, may affect the level of pollutants produced during US 2008/01 12865 A1 May 15, 2008

combustion of the fuel. Moreover, depending on the use of the 0.139. In the early 1980s, most vehicle manufacturers engine, e.g., on-road, off-road, or stationary, there are differ began using converters designed to reduce NOx, in addition ent regulatory requirements with respect to emissions stan to oxidizing HC and CO. These three-way converters, which dards. were used in conjunction with computer controlled engine systems and oxygen sensors, were employed to more pre Location cisely control the air to fuel ratio. These converters are 0133. The catalytic converter can theoretically be placed referred to as three-way converters because they deal with anywhere along the exhaust stream of an engine. However, three compounds: HC, CO and NO. physical characteristics of conventional catalytic converters 0140 Most modern cars are equipped with “three-way’ limit their location. Most commonly in vehicles, the catalytic catalytic converters typically having one or more Substrates in converter is placed some distance from the engine block, tandem using Corning's clay extrusion technology. "Three closer to the muffler and underneath the body of the car. The way” refers to the three regulated emissions the converter catalytic converter is usually not placed close to the engine helps to reduce: carbon monoxide, Volatile organic com because the catalytic converter can fail for several reasons. pounds (VOCs, e.g., unburned hydrocarbons), and NOx mol Such reasons include extreme temperatures, thermal shock, ecules. Such converters use two different types of catalysts, a mechanical vibration, mechanical stress, and space limita reduction catalyst and an oxidization catalyst. tions near the engine. Also, physical setups of stationary 0.141. In a three-way catalytic converter, the reduction engines may limit the location of a catalytic converter or catalyst is usually found in the first stage of the catalytic particular filter. converter and serves to reverse the oxidation of nitrogen that 0134) For example, in its 2004 FOCUSTM, Ford Motor occurred in the combustion chamber. It commonly uses plati Company managed to deploy a mani-catas did Honda Motor num and rhodium to help reduce NOx emissions. The oxida Corporation in one of its offerings. These systems are in tion catalyst, which can be composed of metals such as plati actuality adjacent to, rather than part of the manifold. The num and/or palladium, is commonly located in a second higher temperatures and the extreme vibrational energy gen region of the catalytic converter. erated by cylinder explosions and moving parts would subject 0142. Three-way converters that have a reduction and an current catalytic converters, if placed in a manifold, to oxidation catalyst together in one housing are sometimes extremes in thermal and physical shock. Additionally, a called three-way-plus-oxidation converters. These converters design for a mani-cat was proposed by Northup Grumman use air injection between the two substrates. This air injection Corporation in U.S. Pat. No. 5,692,373. It is believed that aids the oxidation chemical reaction. even the current cordierite substrate would find such an envi 0.143 Four-way converters process carbon monoxide, ronment challenging to endure. nitrogen oxide, unburnt hydrocarbons, and particulate matter. 0135) In other applications, for example such as motor These include, for example, the QuadCAT Four-Way Cata cycles (e.g., Harley-Davidson), the presence of a catalytic lytic Converter manufactured by Ceryx. It is a catalytic con converter in certain locations can cause serious injury to the Verter that that, according to its manufacturer, reduces four of user. Because of the high operating temperatures of a catalytic the major sources of air pollution NOx, hydrocarbons, car converter, it would be preferable to use a catalytic converter bon monoxide and particulate matter to levels that will that is less prone to causing injury to a user, e.g., a smaller allow diesel engines to meet 2002/2004 emissions standards. catalytic converter, a converter that does not get as hot, etc. Others include those described in U.S. Pat. Nos. 4,329, 162: 0136. In certain instances, the exhaust system (for and 5,253,476. example, in a car) may contain more than one catalytic con 0144. The catalytic converter, like other catalysts, facili verter or particular filter along its exhaust flow. (See FIG. 4). tates reactions by lowering the activation energy required to For example, an exhaust system may have an additional cata accomplish the desired reaction. For example, if particulates lytic converter between the engine and the main catalytic require a temperature of 550° C. before reacting with oxygen converter. This configuration is referred to as a pre-cat. The in the presence of catalysts, to burn off, this same reaction pre-cat may have denser configuration. Another set-up is a might require a temperature of only 260° C. This lower back-cat, which has second catalytic converter behind (or energy threshold permits one physically to locate a catalytic after) the main catalytic converter. The back-cat is also some system downstream from the engine where space is more times used for a retrofit catalytic converter. abundant, even though temperatures are cooler. Otherwise, Two Way Vs. Three Way Vs. Four Way the catalytic system will need to be placed upstream where 0.137 Catalytic converters can generally be classified as temperatures are higher. However, this is impractical with being a two-way, three-way, or four-way converter. There are current technology because there is more potential to damage at least the following types of converters commercially avail the Substrate when it is placed closer to the engine. able: oxidation converters, three-way converters (no air), 0145 Diesel engines produce emissions that are high in three-way-plus oxidation converters, and four-way convert NOx and particulate matter due to the high temperature and CS. pressure, while relatively low CO and hydrocarbon produc 0138 Oxidation (two-way) converters represent the early tion. The compression combustion is less complete than with generation of converters that were designed to oxidize hydro a spark of a gasoline engine. However, because of the rela carbons (HC) and carbon monoxide (CO). Although these tively lean mixture with high air content, diesel is able to units represent the most basic form of catalytic converter provide better gas mileage than a gasoline engine. Three-way technology, they remain a viable pollution reduction option in catalysts do not work well in diesel exhaust due to the excess Some areas. Oxidation converters usually contain platinum or air. NOx reduction catalysts typically require a well-main palladium. However, other non-noble metals can be used as tained stoichiometric ratio of fuel-to-air which cannot be well. easily done in diesel combustion engines. US 2008/01 12865 A1 May 15, 2008

0146 Catalytic converter technology may be applied to parallelograms, or shapes that have sides parallel to the extru various applications, including internal combustion engines sion axis. This shape limitation has not been an issue with and stationary combustion engines. The internal combustion previous emission standards. However, the need to design a engine is the most common engine used for vehicles. A cata catalytic converter and particulate filter able to reach near lytic converter is installed as a device in the vehicle's exhaust Zero emissions performance may require non-linear and/or system, so the entire exhaust gas stream passes through the non-cylindrical filter design and vehicle integration. Substrate, contacting the catalyst before being discharged 0151 Decreasing the wall thickness increases the surface from the tailpipe. However, catalytic converters can be also area, e.g., in certain instances, decreasing wall thickness from part of fairly complex systems involving various active strat 0.006 inches to 0.002 inches increases surface area by 54%. egies, such as injection of reactants in front of the catalyst or By increasing the Surface area, more particulate matter may Sophisticated engine control algorithms. Examples include a be deposited in less volume. FIG. 1 shows a prior art honey number of diesel catalyst systems being developed for the comb configuration 102 formed within a ceramic filter ele reduction of NOX. The attributes of simplicity and passive ment 100 configured to increase the surface area for a cata character which have been listed among the advantages of lytic converter. The honeycomb configuration 102 is formed catalysts may no longer apply to those systems. using an extrusion process in which long channels with their 0147 Conventional attempts to reduce pollutant emis major axis parallel to the extrusion action are created. The sions can be very expensive, due partly to both the cost of opening of these channels faces the incoming exhaust airflow. materials and, in certain applications, to retrofitting or manu 0152 Progress in technology has allowed the manufacture facturing an original engine with the appropriate filter. of ceramic cordierite substrates with decreased wall thick ness. The once standard configuration for passenger carappli Advances in Catalytic Converter and Particulate Filter Tech cations, 400/6.5, of 400 cpsi cell density and of 0.0065" (or nology about 0.17 mm) was gradually replaced with substrates of 0148. An invention that lead to progress in catalytic con thinner walls (0.0055 to 0.004 mil). However, the physical verters was Corning's development of extruded cordierite limitations of this material have been approached. Because of honeycomb monoliths. (See U.S. Pat. No. 4,033,779). Since the physical characteristics of ceramics, in particular cordi the 1970's, more than a billion pounds of pollutants have been erite, using Substrates made of cordierite ceramics with even removed from exhaust streams using this approach which thinner walls is not practical. The thinner-walled material is employs catalysts (platinum, palladium, rhodium, etc.) from notable to meet other necessary characteristics (e.g., durabil the noble and base metal families firmly lodged in a washcoat ity, heat resistance). on the Surface of a rugged substrate (generally cordierite) that 0153. Diesel catalysts, in part because of their larger sizes, can withstand the extreme environment of an engine exhaust often have thicker walls than their automotive counterparts. system. Variations and improvements to this core technology Because diesel wall flow filters generally have thicker walls, have evolved in the years since, including variations in the there are physical limitations on the channels per square inch placement of catalytic converters as well as in their compo these filters can have. Generally, there are no commercially sition and methods of manufacture. Still, however, there available diesel wall flow filters having more than 200 chan remain fundamental inadequacies that, to date, have not been nels per square inch. overcome. Currently, the state of technology is reaching 0154 Another limitation of currently available substrates physical and economical limits with only minor improve is their decreased catalytic efficiency at lower temperatures. ments being made at great expense. When a converter system is cold, such as at engine start up, temperatures are not sufficiently high to commence the cata Limitations of Current Substrates lytic reactions. The cordierite, silicon carbide, and various metal Substrates employed in catalytic converters and mar 0149 While the present state of catalytic converter and keted by Corning, NGK, Denso, and other companies today particulate matter filter technology is useful to Some degree are fashioned from very tough, dense materials with excellent for reducing emission pollution, there are certainly draw mechanical strength and tolerances for thermal shock and backs to the current technology. There are also characteristics vibration. However, these materials require time to absorb that are not met by the present catalytic converters. Some heat after startup to reach temperatures sufficient for catalytic inadequacies are inherent to the type of Substrate used. reactions. Due to the delay in the catalysis reaction start-up, it Accordingly, an improved Substrate for use in a catalytic is estimated that approximately 50% of all of the emissions converter or particulate filter would be a significant advance from modern engines are released to the atmosphere during in the fundamental physical and chemical attributes of the the first 25 seconds of engine operation. Even a small materials used as catalyst Substrates in the catalytic converter. improvement during these critical “cold start’ seconds could Moreover, an improved substrate would dramatically drastically improve the amount of pollutants successfully enhance the quality and would enable manufacturers and treated annually. While effort has been invested to address users to meet more easily the emissions standards of 2007, this problem, there remains a need for a catalytic converter and 2010, and later years. that can reduce emissions during this critical cold start period. 0150. The conventional monolithic catalytic converter Even the most advanced and expensive state of the art, cordi Substrate is generally formed through an extrusion process. erite-based catalytic converter requires approximately 20 sec This process, which is both complicated and relatively expen onds to start up. sive, has been used for the past twenty-five years. However, 0155 To more quickly achieve reaction temperatures, there are limitations to the extrusion process. There is a limit attempts have been made to move the converters closer to the as to how small channels can be created within the material engine exhaust manifold where higher temperatures are more and still maintain quality control. The extrusion process also quickly available and also serve to drive reactions more Vig limits the shapes of the catalytic converters to cylinders or orously during operation. Because usable space under the US 2008/01 12865 A1 May 15, 2008

hood of a vehicle is limited, the size of converter systems, and tural integrity: i) efficiency of pollutant treatment; ) amount therefore the amount of throughput that can be successfully of catalyst required; and k) weight of the system. A catalytic treated, is limited. Current substrates cannot be effectively or filtering substrate that optimizes one or more attributes used in the engine compartment of vehicles. Moreover, add would be an advance in the field of filtering fluids and cata ing additional weight to the engine compartment is undesir lyzing reactions. able, and many current Substrates are dense and have limited porosity (roughly 50% or less), requiring systems that are BRIEF SUMMARY OF THE INVENTION both weighty and Voluminous to treat large scale exhaust 0.161 Various embodiments are described in this sum output. Additionally, Substrates such as cordierite are suscep mary. These, as well as other embodiments of the invention, tible to melting under many operating conditions, thereby are described in the following Detailed Description section. causing clogs and increased back pressure. (0162 The inventor has discovered that a non-woven Sin 0156. Other methods of compensating for cold starts tered Refractory Fibrous Ceramic (nSiRF-C) composite, as include elaborate adsorption systems to store NOx and/or described herein, can be used as and shaped into an improved hydrocarbons temporarily so that they might be treated once Substrate for catalytic converters, particulate filters, and the converter has reached critical temperatures. Some of these related devices. systems require parallel piping and elaborate adsorption Sur 0163 The inventor has also discovered that an improved faces, additional valves and control mechanisms, or multiple catalytic Substrate and improved filtering Substrate can be layers of differing washcoats used to adhere catalysts to Sub prepared from a material having particular attributes as strates and to segregate reaction environments. This problem described herein. For example, suitable attributes include is especially challenging in diesel engines where large Vol high melting point, low heat conductance, low coefficient of umes of soot particulates, NOx, and SOX may need to be thermal expansion, ability to withstand thermal and vibra trapped. In some large, industrial diesel engines, rotating tional shock, low density, and very high porosity and perme banks of diesel particulate traps are used to collect, store, and ability. An exemplary material in one embodiment that has subsequently treat particles. (In still other systems, NOx is these attributes is a nSiRF-C. stored and used as an oxidizing agent to convert CO into CO. 0164. One example of a material having suitable attributes while it is reduced to N.) is a nSiRF-C composite. An example of a nSiRF-C is an 0157 Given regulatory restrictions on total emissions, a alumina enhanced thermal barrier (AETB) material or a system that could readily curtail even some of the 50% of like material, which can be used in accordance with embodi emissions that occur during cold start might obviate the need ments of the present invention as a catalytic substrate or a for some of the expensive and elaborate work-arounds filtering substrate. AETB materials are known in the art and described above. Used in conjunction with these work comprise aluminaboriasilica (also known as alumina-boria arounds. Such a system could result it in Substantially silica, aluminoborosilicate, and aluminoboriasilicate) fibers, decreased emissions. However, as explained above, conven silica fibers, and alumina fibers. One commonly known appli tional systems are generally complicated and expensive and cation for AETB is as an exterior tile on the Space Shuttle, also tend to misfire and/or work unpredictably. ideal for shuttle re-entry. AETB has not been used as a filter 0158 Another inherent limitation of conventional systems ing Substrate or a catalytic converter Substrate. is the typical “residence time required to burn off particu 0.165. It has been realized by the present inventor that the lates. When one considers the large Volume of exhaust gas attributes that make AETB desirable to the space industry are throughput during operation and the speed at which the gas also preferred in combustion technology. Among other must flow, it is important that a converter be capable of rapid attributes, AETB has a high melting point, low heat conduc light off. Thus, a catalytic converter capable of rapid light off, tance, low coefficient of thermal expansion, ability to with of enduring extreme thermal and vibrational shocks, and stand thermal and vibrational shock, low density, and very capable of rapid internal temperature build up during cold high porosity and permeability. This combination of desired starts, would greatly enhance the capability of industry to attributes is lacking in current filtering and catalytic converter reduce emissions, meet upcoming environmental standards Substrates. for 2007 and 2010, and produce cleaner operating cars, 0166 It has also been discovered that nSiRF-C compos trucks, buses, and heavy industrial engines. ites, such as AETB and similar suitable substrates, can be 0159. If the substrate were also lightweight, it would also prepared, shaped, molded, cut, and/or fashioned (or other result in improved mileage statistics on new vehicles. To date, wise modified physically) into new forms suitable for use as however, no substrate has been identified capable of address particulate filter and catalytic converter Substrates. ing many or all of these problems. 0167. The present invention has a number of advantages over current technology. First, the present invention will lead Design Considerations for a Substrate for a Catalytic Con to improved air quality and respiratory health. The present verter or Particulate Filter invention may substantially reduce the potential for carbon 0160 Catalyst substrate is a crucial component influenc monoxide poisoning. ing performance, robustness, and durability of catalytic con 0168 Embodiments of the present invention can be used Verter systems. Furthermore, filtering Substrates significantly as a direct Substitute for currently used catalytic and filtering affect the operating performance of particulate filters. Ideally, Substrates, as well as catalytic converters and particulate fil the substrate used in a catalytic converter or particulate filter ters, and exhaust and engine systems. As described in fine should have a number of attributes. These attributes include, detail below, the substrates of the present invention provides but are not necessarily limited to, one or more of the following a number of advantages over prior art Substrates and further aspects: a) Surface area; b) porosity/permeability; c) emissiv solves a number of problems left unsolved by the prior art ity; d) heat conductance; f) thermal attributes Such as shock Substrates. This can translate into significant cost savings on resistance, expansion, and conductance; g) density; h) struc the part of the manufacturers. Because it is possible to use the US 2008/01 12865 A1 May 15, 2008

present invention as a direct Substitute for current technology, ware; additional hardware (that might be required due to there is no need to redesign exhaust systems. Thus, enhanced tighter regulations) would not be necessary with the present exhaust filtering and cleaning can be obtained without the invention; decreased or eliminated discoloration of muffler need to retool manufacturing plants and lines and with only and exhaust pipes due to exothermic chemical reactions. The minimal investment in time. present invention allows in certain embodiments a smaller 0169. The improved catalytic and filtering characteristics Substrate, and thus a smaller muffler or canister in certain of the present invention require, in certain embodiments, the systems. The substrate of the present invention provides use of less catalyst. Because most catalysts used for the rel increased safety for systems using a catalytic converter or evant applications are expensive, this advantage leads to particulate filter because the substrate of the present invention another cost-saving. has improved thermal properties and does notabsorb as much 0170 The preferred thermal attributes of some embodi heat as certain conventional substrates. Moreover, the sub ments of the present invention reduce and/or eliminate the strate of the present invention cools off faster than many need for certain parts of the exhaust system that deal with the conventional Substrates, leading to increased safety. Certain heat build-up associated with current catalytic converters and embodiments of the present invention provide for improved particulate filters. Heat shields and insulation may not be resistance to temperature change and therefore will not crack, needed in certain embodiments of the present invention. fracture, or become damaged as much as certain conventional Elimination of these components from exhaust systems and Substrates if there is a Sudden temperature change. In certain vehicles reduces cost only directly (components are not used, embodiments, the Substrate is easier to manufacture than thus lower costs of production) but also indirectly (the weight conventional substrates (e.g., a nSiRF-C wall flow substrate of a vehicle is reduced, thus reducing fuel costs). Other ben can be manufactured from a single piece of material rather efits may include better performance, better mileage, and/or than plugging channels). This attribute saves not only time but better horsepower. also money. 0171 In certain embodiments, a conventional catalytic 0176). In other embodiments, a nSiRF-C weighs less than converter or particulate filter can be replaced with the present conventional aftertreatment devices. This attribute is not only invention that is smaller but has the same or better efficiency important for cars, but also crucial in markets where weight is of removing pollutants. With a smaller catalytic converter or a factor (e.g., Small engines, motorcycles, personal water particulate filter, more space is available on the vehicle for craft, and performance cars). other purposes. Furthermore, because the filter or converter of 0177. In some embodiments, the substrate of the present the present invention is smaller, the overall weight of the invention exhibits a less backpressure than competing after vehicle is reduced. treatment devices. This lower backpressure can results in 0172 Another aspect of some embodiments of the present increased vehicle performance, increased horsepower, and invention is a catalytic Substrate Suitable for use in a catalytic increases fuel economy. converter that is placed, either wholly or in part, in the head of 0178. Other embodiments of the invention are directed to, an engine Said catalytic converter, referred to herein as head for example, a method catalyzing reaction, a method of fil cat, has numerous advantages over the prior art. For example, tering a fluid, a process of preparing a catalytic Substrate, a conventionally such a head cat is not practical because of the process of preparing a filtering Substrate, a Substrate prepared limitations of currently available catalytic substrates. The according to said processes, and others as described in more common substrate cordierite would absorb too much heat. detail below. Because of the preferred thermal characteristics of the sub strate of the present invention, a head cat comprising said BRIEF DESCRIPTION OF THE DRAWINGS substrate would reduce turbo thermal stress on a turbocharger 0.179 FIG. 1 is a cross-sectional view of a conventional and/or intercooler if present. cordierite substrate incorporating a honeycomb structure. 0173 Also a head cat does not require additional external The honeycomb configuration302 is formed within the cordi hardware such as heat shields. The use of a head cat permits erite filter element 300. The honeycomb structure 302 is the maintenance of preferred appearances of engines and formed using an extrusion process in which long channels (or products, such as in motorcycles. In certain embodiments, the tubes) with their major axis parallel to the extrusion action are use of a head cat also reduces external discoloration of the created. The openings of these channels face the incoming exhaust system, Such as mufflers and header pipes. A number exhaust airflow. As the emissions enter the channels, the of additional advantages of the head cat in certain embodi particulate will deposit along the interior septum of the tubes. ments include one or more of the following: increased safety; 0180 FIGS. 2a and 2b show micrographs of cordierite. In filters particles that intercooler would otherwise pick up, FIG. 2b, sphere 210 represents a PM-10 sized particle and hence improving life of inter-cooler and providing a cost sphere 225 represents a PM-2.5 sized particle. saving; no matting required in certain embodiments; rattling 0181 FIG. 3 is a micrograph of SiC 300. sounds in heat shields can be reduced or eliminated with the 0182 FIG. 4a is a longitudinal cross-sectional view of a use of a head-cat, and the head cat can reduce the size of the typical catalytic converter schematic diagram. The catalytic requisite muffler. converter 400 includes a reduction catalyst 402 and an oxi 0.174. In other embodiments of the head cat; smaller par dation catalyst 404. As exhaust flow 406 enters the catalytic ticulate matter is more efficiently burnt off. In case of failure converter 400 it is filtered and exposed to the reduction cata of a head-cat, only one Small cat may need replacement. lyst 102 and then to the oxidation catalyst 404. The exhaust Head-cats are also provide these advantages to for boats, flow 406 is then treated by the oxidation catalyst 404 which watercraft, motorcycles, leaf-blowers etc. causes unburned hydrocarbons and carbon monoxide to burn 0175 More, different embodiments of the present inven further. tion provide one or more of the following advantages over the 0183 FIG. 4b shows a schematic diagram of a catalytic prior art: improved appearance; avoidance of additional hard converter. US 2008/01 12865 A1 May 15, 2008

018.4 FIG. 5 is a cross-sectional view of a schematic of 0193 FIGS. 14a-d show an embodiment of the present three substrates of having three different frontal surface invention. The microscopic view shows the substantially shapes. similar dimensions of rectangular-shaped channels 1410. 0185 FIG. 6 is an example schematic diagram of a flow 1411, 1412, 1413 in a substrate 1415, 1416, 1417, 1418. through configuration of a catalytic or filtering Substrate. The FIGS. 14c and 14d illustrate the fibers 1420, 1421 present in substrate has a plurality of channels 610 formed by channel the material. These fibers show the porosity, which is superior walls 620. The fluid flow 630 enters the frontal Surface and to the platelets of cordierite in conventional systems. travels through the channels 610 and exits the rear surface. 0194 FIG. 15 is a two-dimensional diagram of a comb 0186 FIG. 7 is an example schematic diagram of a wall 1500 that can be used in a combing method of preparing a through configuration of a catalytic or filtering Substrate. A catalytic or filtering Substrate of the present invention. wall-flow pattern is composed of the same substrate material (0195 FIG. 16 shows various views of a comb 1600 (or 720 and channels 710, except the channels 710 do not connect portion thereof) that can be used in certain embodiments of completely to the other side. Instead, the channels 710 are the present invention. FIG.16 also provides exemplary physi formed as blind holes, leaving an undrilled portion 740 of cal dimensions in inches of comb 1600. Substrate 720 at the end of the channel 710. The fluid flow 730 0.196 FIG. 17 is a schematic diagram of the surface area than passes through a channel wall 720 before exiting the enhancements and entry and exit tubes which can be formed Substrate at the rear Surface. One particular advantage of the in the filter element of embodiments of the present invention. present invention is that fluid flow 730 in the wall-flow pattern FIG. 17 provides fluid flow 1704 entering channel openings has substantially the same characteristics as the flow-through 1702 on the frontal surface. Fluid exits the rear surface of the pattern. substrate at 1704 on the right hand side. The substrate shown 0187 FIG. 8 is an example schematic diagram of a wall in FIG.17 exemplifies a substrate having a wall-flow configu through configuration of a catalytic or filtering Substrate. In ration, wherein the channels gradually decrease in size as the this instance, fluid flow 830 enters the substrate at the frontal channel extends from the channel opening through the Sub surface. Some of the fluid exits the substrate at the rear surface strate to the channel terminus. by flowing through an undrilled portion 845. Some channels 0.197 FIG. 18 is a longitudinal view (photograph) of an 0188 FIG. 9 is an end view of an embodiment of a sub embodiment substrate embodiment of the present invention. strate 900 that employs wall flow channels. Alternating chan A filter substrate 1800 of the present invention is shown. The nels have an undrilled portion 920 at either the ingress or substrate 1800 has a hard coating 1804 on the outside wall egress. Drilled channels 910 alternate withundrilled portions 1802. For the sample shown in FIG. 18, the hard coating 920 of channels drilled from the opposing side. As a result, the consists of finely crushed cordierite and inorganic fibers. A substrate appears to have a “checkerboard' pattern of chan powder was also painted on the filter foundation 1800 and nels. cured as described herein. The hard coating protects and 0189 FIGS. 10a–10a show a comparison of frontal sur insulates the filter foundation while not changing the dimen face area 1020, 1021, 1022, 1023 and number of cells 1010, S1O.S. 1011, 1012, 1012 is shown. In a comparison of FIGS. 10a and 0198 FIG. 19 is a graphical display of the residence time 10c, each embodiment has the same cell density, i.e., number required to burn particulate matter at varying temperatures. It of channels or cells. However, FIG. 10c has a much higher provides the residence time required to combust or burn par frontal Surface area. Ideally, the frontal Surface area is mini ticulate matter (soot mass) at various temperatures. As seen, mized such that structural integrity still remains. A similar the residence time to combust or burn soot mass having an comparison may be made between the embodiments of FIGS. initial 0.9 soot mass at 600 Kelvin is much longer than the 10b and 10d. Regarding FIGS. 10a-10a, the embodiment of residence time at 1200 Kelvin. FIG. 10b has the preferable structure; cell density is maxi (0199 FIG. 20 provides an exhaust substrate system 2000 mized and frontal Surface area is minimized. including a substrate 2002 combined with a wire mesh heat 0.190 FIG. 11 shows an embodiment of square channels to ing element 2004. The substrate 2002 and wire mesh heating scale. In this embodiment, the cell void 1110 to cell wall 1120 element 2004 are inserted into the exhaust casing 2006 at an ratio is 31.83:1.5, or approximately 20:1. angle compared to the exhaust flow. Since the wire mesh (0191 FIG. 12 shows an embodiment of a substrate 1210 heating element 2004 is placed behind and below the sub having an exemplified cell void to cell wall ratio shown to strate 2002 as a result of the angle, the substrate 2002 can be scale. The substrate 1210 is four square inches in length and heated more efficiently and uniformly taking advantage of the width and comprises four squares 1220, 1221, 1222, 1223 of known principal that heat rises. As previously discussed, 1/8 inches by 1/8 inches. Each of the four squares 1220, 1221, more uniform and efficient heating enables the substrate 2002 1222, 1223 is drilled to have a cell density of 900, for a total to more completely combust or flash off the particulates substrate cell density of 3600. The wall thickness between the resulting in cleaner exhaust. cells is 1.5 mil. The spacing between each square 1220, 1221, (0200 FIG. 21 is a diagram of a frontal view of the filter 1222, 1223 on the substrate 1210 is 7/8 inches and the squares element 2102 and wire mesh heating element 2104 described 1220, 1221, 1222, 1223 are each approximately 7/16 inches and discussed in relation to FIG. 9. As can be seen the filter from the closest edge of substrate 1210. element 2102 and wire mesh heating element 2104 are oval (0192 FIGS. 13a-c is show several embodiments of the shaped so as to fit in the casing at an angle. The shape of the channels structure FIGS. 13a-13c show hexagonal channels casing, shape of the filter element 2102, type of heating ele 1310, triangular 1320, and square channels 1330, respec ment 2104 and angle can all be modified to fit the require tively. These embodiments are all successful in carrying out ments and restrictions of the intended exhaust system appli the present invention because the walls 1315, 1325, 1335 of cation. the channels 1310, 1320, 1320 are substantially parallel to 0201 FIG. 22a is a photomicrograph of a substrate of the each other. present invention, specifically AETB. US 2008/01 12865 A1 May 15, 2008

0202 FIG.22b is a photomicrograph of a substrate of the eliminating pollutants from the exhaust of combustion present invention, specifically AETB. Fiber 2205 can be seen. engines. The catalytic Substrate and filtering Substrate pro Sphere 2210 illustrates a PM-10 sized particle, and Sphere vide, in certain embodiments, improvements in removing 2225 illustrates a PM-2.5 sized particle. pollutants from an exhaust gas. The improvements include, 0203 FIG.23 is a graph showing pressure drop (deltaP) as but not limited to, one or more of the following: faster light a function of gas hourly space velocity (hr') for seven mate off period, increased depth filtration of PM, less back pres rials: Corning 200/12 DPT at 932 F (2340); AETB-11 having Sure, lower probability of clogging, increased ability to be 600 cpsi, 6 mil wall thickness and 11 lb/ft at 1100 F (2310); placed in multiple locations in the exhaust system including AETB-11 having 600 cpsi, 6 mil wall thickness and 11 lb/ft the manifold or the head itself, high probability of catalytic at 932 F (2320): AETB-11 having 600 cpsi, 6 mil wall thick reaction, high conversion ratios of NOx, HC, and CO, a faster ness and 11 lb/ft at 662 F (2330); cordierite having 400 cpsi burnoff of PM, minimization of catalyst material use, reduced and 6 mil wall thickness at 1100 F (2350); cordierite having weight of the after-treatment exhaust system, and the like. 400 cpsi and 6 mil wall thickness at 932 F (2360); and cordi 0211. Other embodiments of the invention include cata erite having 400 cpsi and 6 milwall thickness at 662F (2370). lytic converters, particulate filters, diesel particulate filters, Data for cordierite are calculated. diesel particulate traps, and the like. The present invention 0204 FIG. 24 is a graph showing the '% destruction versus also provides a process of making or preparing the catalytic temperature. A substrate of the present invention 2410 shows and filtering Substrates, catalytic converters, particulate fil a greater percentage of destruction of material at lower tem ters, catalytic mufflers, and exhaust systems. Other embodi peratures than a cordierite substrate 2420. ments of the present invention include a pre-cat, a back-cat, a 0205 FIG. 25 is a diagram of a cross sectional view of an head-cat, and a mani-cat, each of which comprises a Substrate embodiment of an improved catalytic converter of the present of the present invention. Additionally, the present invention, invention. In this embodiment, the catalytic converter com in alternative embodiments, is directed to a substrate made prises a durable and heat resistant casing 2502. The casing according to the process described herein. 2502 has an intake 2504 and an exhaust port 2506. The 0212. In another aspect, the present invention includes a improved substrate 2510 has one or a plurality of Zones 2512. catalytic substrate or filtering substrate that offers one or more 2514. The improved substrate 2510 is wrapped or enclosed in of the following attributes: a faster light-off period, increased one or more layers of matting/insulation 2515. The matting depth filtration of PM, a lower backpressure, a lower prob layer 2515 may be applied to the filter foundation 2510 to ability of clogging up, an ability to be placed in multiple shield the foundation 2510 from engine and mobile environ locations in the exhaust system including the manifold or the ment vibrational shock as well as to insulate the exterior head itself, a higher probability of catalytic reaction, a higher environment from internal thermal temperatures of the filter conversion ratios of pollutants such as NOx, HC, CO, faster foundation 2510. burnoff of PM, a lower amount of catalyst material needed, 0206 FIG. 26 is a shows a schematic of a catalytic con faster light-off in for cold starts, lower external wall tempera verter or particular filter 2600 having four substrates 2601a, ture of the substrate, and the like. 2601b, 2601c, and 2601d arranged in a parallel fashion. The 0213. Using a substrate, catalytic converter, particulate filter or converter has a frontal opening 2604 and an rear exit filter, or exhaust system of the present invention provides a 2605. number of advantages and improvements over the prior art. In 0207 FIGS. 27a-c shows a catalytic converter or particu certain embodiments, these improved catalytic converters late filter 2700 having stacked membrane configuration sub and/or particulate filters are able to remove and/or eliminate strates 2710. The inlet port 2720 and outlet port 2730 are pollutants from the exhaust of combustion engines with a fashioned at different heights. FIGS. 27b and 27C show alter number of specific advantages, as described in more detail native embodiments. below. Improved exhaust systems are likewise an additional 0208 FIG. 28 is a photograph of a substrate/filter in a wall aspect of the invention described herein. The improved flow configuration made according to an embodiment of the exhaust system reduces the amount of pollutants emitted present invention, with the following attributes: 1 inch diam from the operated engine. eter by 1 inch thickness, the channel pattern covered by 0.8 0214. The present invention, including nonlimiting inch by 0.8 inch. embodiments and examples, are described in more detail 0209 FIG.29 is a graph that illustrates the drop in pressure below. The embodiments discussed herein are provided for measured in a reactor-tube flow-measurement system as a illustrative purposes only. The invention is not limited to these function of gas flow rate for temperature so 27°C., 29°C. and embodiments. 400° C. for an embodiment of the present invention. Catalytic Substrate DETAILED DESCRIPTION OF EMBODIMENTS 0215. The present invention is directed to a catalytic sub OF THE INVENTION strate comprising, or alternatively consisting of or consisting essentially of, a non-woven Sintered Refractory Fibrous Overview Ceramic (nSiRF-C) composite, as described herein, that can 0210. The present invention in certain embodiments is be used in catalytic converters, particulate filters, and related directed to a catalytic substrate suitable for use in a number of devices; and optionally further comprising an effective applications, including as a Substrate in a catalytic converter. amount of a catalyst, Such as a catalytic metal. Preferably, the Another aspect of the present invention is a filtering Substrate catalytic substrate comprises a catalyst. The nSiRF-C com Suitable for use in a number of applications, including as a posite can be shaped into configurations suitable for uses Substrate in a particulate filter, Such as a diesel particulate described herein. filter (DPF), or diesel particulate trap (DPT). The invention 0216. The nSiRF-C composite is non-woven. In certain also provides an improved substrate for removing and/or embodiments, the nSiRF-C composite is a material having a US 2008/01 12865 A1 May 15, 2008

definitive, rigid three-dimensional shape. The fibers of the about 3 to about 5 weight percent silica in commercial form. nSiRF-C composite are not arranged in an organized pattern In other embodiments, alumina having a lower purity are also but are arranged three-dimensionally in a random, haphazard, useful, e.g., 90%, 92%, and 94%. In other embodiments, or omnidirectional fashion. In some embodiments, the alumina having a higher purity are also useful. Alumina can nSiRF-C is in the form of a matrix. be produced by extruding or spinning. First, a solution of 0217. The nSiRF-C is a sintered composite. In one precursor species is prepared. A slow and gradual polymer embodiment, a sintered composite is a cohesive mass formed ization process is initiated, for example, by manipulation of by heating without melting. However, the process ofsintering pH, whereby individual precursor molecules combine to form a ceramic material is well-known in the art, and thus the scope larger molecules. As this process proceeds, the average of the present invention is not necessarily limited to specific embodiments and descriptions described herein. Sintering molecular weight/size increases, thereby causing the Viscos creates bonds without resin residue. With reference to the ity of the solution to increase with time. At a viscosity of about present invention, the sintered ceramic is a cohesive mass of ten centipoise, the solution becomes slightly adhesive, allow dispersed fibers formed by heating without melting. ing fiber to be drawn or spun. In this state, the fiber may also 0218. The nSiRF-C is a refractory fibrous ceramic com be extruded through a die. In certain embodiments, the aver posite. The nSiRF-C of certain embodiments is composed of age fiber diameter ranges from about one to six microns, high grade refractory fibers of various lengths and composi although larger and Smaller diameter fibers are also suitable tions as exemplified in nonlimiting embodiments herein. for the present invention. For example, the fiber diameters in 0219. In one embodiment, the present invention is directed other embodiments range from 1-50 microns, preferably 1-25 to a catalytic Substrate Suitable for use in a number of appli microns, more preferably 1-10 microns. cations as described herein. Such a Substrate includes a num 0224. In one embodiment, a second component of an ber of materials which have one or more, preferably a plural AETB is silica fiber. Silica (SiO, e.g., Q-fiber or quartz ity of attributes as described herein. The substrate of the fiber), in certain embodiments, contains over 99.5 weight present invention is made of a non-woven, fibrous ceramic percentamorphous silica with very low impurity levels. Silica composite made from refractory grade fibers. Such a material oflower purities, e.g., 90%. 95%, and 97%, are also useful for is disclosed in U.S. Pat. No. 4,148,962, which is incorporated the invention. In certain embodiments, anamorphous silica is herein by reference in its entirety. Other suitable materials are used that has a low density (e.g., 2.1 to 2.2 g/cm), high disclosed in U.S. Pat. No. 3,952,083. refractoriness (1600 degrees Celsius), low thermal conduc 0220. In one embodiment, the catalytic Substrate of the tivity (about 0.1 W/m-K), and near Zero thermal expansion. present invention comprises, or alternatively consists or con sists essentially of an alumina enhanced thermal barrier 0225. In one embodiment, a third component of an AETB (AETB) material or a like material known to one of ordi is aluminaboriasilica fibers. In certain instances, aluminabo nary skill in the art. AETB material is known in the art and riasilica fiber (3 Al-O.2SiO.B.O., e.g., NEXTEL 312) is more fully described in Leiser et al., “Options for Improving typically 62.5 weight percent alumina, 24.5 weight percent Rigidized Ceramic Heatshields”. Ceramic Engineering and silica, and 13 weight percent boria. Of course, the exact Science Proceedings, 6, No. 7-8, pp. 757-768 (1985) and percentages of the constituents of the aluminaboriasilica may Leiser et al., “Effect of Fiber Size and Composition on vary. It is largely an amorphous product but may contain Mechanical and Thermal Properties of Low Density Ceramic crystalline mullite. Suitable aluminaboriasilica fibers and Composite Insulation Materials”, NASA CP 2357, pp. 231 methods of making the same are disclosed, for example, in 244 (1984), both of which are hereby incorporated by refer U.S. Pat. No. 3,795.524, the teachings of which are herein CCC. incorporated by reference in their entirety. 0221. In another embodiment, the catalytic substrate com 0226. Another suitable material for use as a substrate of prises Ceramic tiles. Such as alumina enhanced thermal bar the present invention includes Orbital Ceramics Thermal Bar rier (AETB) with toughened unipiece fibrous insulation rier (OCTB), available from Orbital Ceramics (Valencia, (TUFI) and/or reaction cured glass (RCG) coatings. Such Calif.). materials are known in the art. 0227. Other suitable materials for use as a nSiRF-C in the 0222 Another suitable material is Fibrous Refractory present invention include: AETB-12 (having a composition Ceramic Insulation (FRCI). In one embodiment, AETB is of about 20% Al-O, about 12% (14% B.O., 72% Al-O. made from aluminaboriasilica (also known as alumina-boria 14% SiO; NEXTELTM fiber), and about 68% SiO): AETB-8 silica, aluminoborosilicate, and aluminoboriasilicate) fibers, (having a composition of about 20%. Al-O, about 12% (14% silica fibers, and alumina fibers. One commonly known appli BO, 72% Al-O, 14% SiO, NEXTELTM fiber), 68% SiO); cation for AETB is as an exterior tile on the Space Shuttle, FRCI-12 (having a composition of about 78% wt. silica ideal for shuttle re-entry. AETB has a high melting point, low (SiO), and 22% wt. aluminoborosilicate (62% Al-O, 24% heat conductance, and coefficient of thermal expansion, abil SiO, 14% BO); and FRCI-20 (having a composition of ity to withstand thermal and vibrational shock, low density, about 78% wt. silica (SiO) and about 22% wt. aluminoboro and very high porosity and permeability. Thus, in a preferred silicate (62%. Al-O, 24% SiO, 14% BO). embodiment, the catalytic Substrate has a high melting point, 0228. In a preferred embodiment, the components of the low heat conductance, coefficient of thermal expansion, an inorganic fibers consists, or consists essentially of fibrous ability to withstand thermal and vibrational shock, a low silica, alumina fiber, and aluminoborosilicate fiber. In this density, a high porosity, and a high permeability. embodiment, the fibrous silica comprises approximately 0223) In one embodiment, a first component of AETB is 50-90(%) percent of the inorganic fiber mix, the alumina fiber alumina fibers. In preferred instances of the present invention, comprises approximately 5-50(%) percent of the inorganic the alumina (Al-O or aluminum oxide, e.g., SAFFIL), is fiber, and the aluminoborosilicate fiber comprises approxi typically about 95 to about 97 weight percent alumina and mately 10-25(%) percent of the inorganic fiber mix. The US 2008/01 12865 A1 May 15, 2008 20 fibers used to prepare the substrate of the present invention Fiber 550, NEXTELTM Ceramic Fiber 610, and NEXTELTM may have both crystalline and glassy phases in certain Ceramic Fiber 720. The composite grade fibers NextelTM embodiments. Fibers 610, 650, and 720 have more refined crystal structures 0229. Other suitable fibers include aluminoborosilicate based on alpha-Al-O and do not contain any glassy phases. fibers preferably comprising aluminum oxide in the range This allows them to retain strength to higher temperatures from about 55 to about 75 percent by weight, silicon oxide in than the industrial fibers. NextelTM Fiber 610 has essentially a the range from less than about 45 to greater than Zero (pref single-phase composition of C-Al-O. It has the lowest erably, less than 44 to greater than Zero) percent by weight, strength retention attemperature eventhough it starts with the and boron oxide in the range from less than 25 to greater than highest strength at room temperature. Both NextelTM Fiber Zero (preferably, about 1 to about 5) percent by weight (cal 650, which is C.-Al-O with Y.O. and ZrO additions, and culated on a theoretical oxide basis as Al-O, SiO, and BO, NextelTM Fiber 720 which is alpha-Al-O, with SiO, added respectively). The aluminoborosilicate fibers preferably are (forming O-AlO/mullite) have better strength retention at at least 50 percent by weight crystalline, more preferably, at temperature and lower creep. least 75 percent, and most preferably, about 100% (i.e., crys 0235. In another suitable embodiment, a nSiRF-C is made talline fibers). Sized aluminoborosilicate fibers are commer from or comprises (or alternatively, consists of or consists cially available, for example, under the trade designations essentially of) ceramic fibers comprising Al-O, SiO, and “NEXTEL312 and “NEXTEL 440 from the 3M Company. BOs, having the following attributes: 1) melting point of Further, suitable aluminoborosilicate fibers can be made as about 1600° C. to about 2000° C., preferably about 1800° C.: disclosed, for example, in U.S. Pat. No. 3,795.524, which is 2) a density of about 2 to about 4 g/cc, preferably about 2.7 to incorporated herein by reference in its entirety. about 3 g/cc; 3) a refractive index of about 1.5 to about 1.8, 0230. Additional suitable fibers include aluminosilicate more preferably selected from 1.56, 1.60, 1.61, 1.67, and fibers, which are typically crystalline, comprising aluminum 1.74; 4) a filament tensile strength (25.4 mm gauge) of about oxide in the range from about 67 to about 77, e.g., 69, 71, 73 100 to about 3500 MPa, more preferably from about 150 to and 75, percent by weight and silicon oxide in the range from about 200 or from about 2000 to about 3000, or selected from about 33 to about 23, e.g., 31, 29, 27, and 25, percent by 150, 190, 193, 2100, or 3100; 5) a thermal expansion (100 weight. Sized aluminosilicate fibers are commercially avail 1100° C.) from about 2 to about 10, preferably about 3 to able, for example, under the trade designation “NEXTEL about 9, more preferably selected from 3, 4, 5.3, 6, and 8; 6) 550 from the 3M Company. Further, suitable aluminosilicate and a surface area of less than about 0.4 m/g, more preferably fibers can be made as disclosed, for example, in U.S. Pat. No. less than about 0.2 m/g. In other embodiments, the crystal 4.047.965 (Karst et al.), the disclosure of which is incorpo phase of the fibers are mullite and amorphous, substantially rated herein by reference. amorphous, Y-AlOs, or amorphous SiO. In still other 0231. In other embodiments, the fibers used to prepare the embodiments, the dielectric constant of a fiber that is suitable Substrate of the present invention comprise C-Al-O with for use in preparinga Substrate according to the present inven YO, and ZrO, additions, and/or c-Al-O, with SiO, added tion is about 5 to about 9 (at 9.375 GHz), or preferably (forming C.-AlO/mullite) selected from the group consisting of 5.2, 5.4, 5.6, 5.7. 5.8, 6. 0232 Various specific materials can be used to prepare the 7, 8, and 9. catalytic Substrate. In one embodiment, the material used to 0236. In certain embodiments, the substrate of the present prepare a Substrate of the present invention comprises, or invention is substantially “shot-free” meaning free of particu alternatively consists or consists essentially of refractory late ceramic (i.e., crystalline ceramic, glass, or glass-ceramic) silica fibers and refractory aluminumborosilicate fibers. In from the fiber manufacture process. another embodiment, the material used to prepare the cata 0237. In certain embodiments, the nSiRFC composite is lytic substrate comprises refractory silica fibers, refractory “nonflexible.” In one embodiment, nonflexible refers to a grade alumina fibers, and a binding agent, preferably a boron Substrate that cannot be bent more to an angle of 1, 2, 3, 4, 5, oxide or a boron nitride powder. In another embodiment the 6, 7, 8, 9, 10, 15, 20, or 25 degrees (with respect to the point fibers are high grade. of bending) withoutbreaking, cracking, or becoming perma 0233. In another embodiment, the substrate comprises a nently deformed or misshapen. refractory composite consisting essentially of aluminosili 0238. The diameter of the fibers used different embodi cate fibers and silica fibers in a weight ratio within the range ments of the invention may vary. In certain embodiments, the of about 19:1 to 1:19, and about 0.5 to 30% boron oxide, average diameter is from about 1 to about 50 microns, pref based on the total weight of the fibers. Alternatively, the erably 1 to about 20 microns. In other embodiments, the weight ratio of aluminosilicate fibers to silica fibers is average diameter is about 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 selected from 16:1, 14:1, 12:1, 10:1, 8:1; 6:1, 4:1, 2:1, 1:1, microns. In other embodiments, the average fiber diameter for 1:2, 1:4, 1:6, 1:8, 1:10, 1:12, 1:14, and 1:16. The boron oxide aluminiaboriasilica fibers is from about ten to about twelve is present in other embodiments in about 5%, 10%, 15%, microns. 20%, 25%, or 30%. In a further embodiment, the boron oxide 0239. In another embodiment, the catalytic substrate of and aluminosilicate fibers are present in the form of alumi the present invention further comprises a binding agent Such noborosilicate fibers. In a further embodiment, the catalytic as boron nitride. In another embodiment of the present inven substrate comprises a nSiRF-C composite wherein the alumi tion, boron nitride is added to replace the aluminaboriasilica nosilicate fiber to silica fiber ratio ranges from 1:9 to 2:3 and fiber when it is not used. That is, in some embodiments, the the boron oxide content is about 1 to 6% of the fiber weight. Substrate comprises (or consists of or consists essentially of 0234. In another embodiment, fibers suitable for preparing or is made from) silica fiber, alumina fiber, and boron nitride the substrate of the present invention include the refractory in similar weight percentage as described above. In a further fibers produced by 3M such as NEXTELTM Ceramic Fiber embodiment, the Substrate comprises silica fiber, alumina 312, NEXTELTM Ceramic Fiber 440, NEXTELTM Ceramic fiber, and a boron binder. Each of these may, in certain US 2008/01 12865 A1 May 15, 2008

embodiments, contain Small amounts of other material Such derivatives thereof including oxides, and mixtures thereof. In as organic binders, inorganic binders and some fibrous or addition, the catalysts are not restricted to noble metals, com non-fibrous impurities. In other embodiments, the substrate binations of noble metals, or only to oxidation catalysts. does not contain an organic binder. Furthermore, in other Other Suitable catalysts include chromium, nickel, rhenium, instances, the binder that is used to create the nSiRF-C is ruthenium, silver, osmium, iridium, platinum, and gold, iri materially changed during the process of making, as is known dium, derivatives thereof, and mixtures thereof. Other suit in the art. able catalysts include binary oxides of palladium and rare 0240 Additional suitable materials for use in preparing earth metals as disclosed in U.S. Pat. Nos. 5,378,142 and the substrate of the present invention are disclosed in U.S. Pat. 5,102,639, the disclosures of which are hereby incorporated No. 5,629,186 which describes low density fused fibrous ceramic composites prepared from amorphous silica and/or herein by reference. These binary oxides may result from the alumina fibers with 2 to 12% boron nitride by weight offibers. solid state reaction of palladium oxide with the rare earth In another embodiment, a thickening agent is added. Suitable metal oxides, to produce, e.g., SmPdO7, NdPdOz, PrPdO, thickening agents are known in the art. or La4PdC). Other catalysts that can be used in the present 0241. In other embodiments, the ceramic fibers used to invention include those disclosed in U.S. Pat. No. 6,090,744 prepare the nSiRF-C have an average tensile strength greater (assigned to Mazda Motor Corporation). Other suitable cata than about 700 MPa (100,000 psi), preferably greater than lysts include non-metallic catalysts, organic catalysts, base about 1200 MPa (200,000 psi), more preferably, greater than metal catalysts, precious metal catalysts, and noble metal about 1800 MPa (300,000 psi), and most preferably, greater catalysts. than about 2100 MPa (350,000 psi). 0250 Other suitable catalysts are disclosed in U.S. Pat. 0242. In another embodiment, a dispersant is added. Suit No. 6,692.712 (assigned to Johnson Matthey Public Limited able dispersants are known in the art. Company). Catalysts that do not comprise precious metals 0243 In other embodiments, the catalytic substrate is may be used in the present invention. Such catalysts are treated with, altered, modified, and/or enhanced in one or shown in U.S. Pat. No. 5,182,249. more aspects as described herein and/or as is known in the art. 0251 Another suitable platinum catalyst developed by 0244 Instill other embodiments, minor impurities of vari Engelhard is composed of Pt/Rh at 5:1 ratio (applied in an ous sources are present. In these cases, the impurities do not amount of about 5-150 g/ft) and MgO (applied in an amount substantially affect the nSiRF-C and/or its attributes. of about 30-1500 g/ft). 0245. A substrate according to the present invention does 0252. In other embodiments, vanadium and derivates not include a NEXTELTM woven fabrics or mat. thereof, e.g., V.O.s, are useful catalysts, in particular for die sel particulate filters. Such catalysts have been used in com Catalyst mercially available in diesel particulate filters. 0246. In another aspect, the present invention is directed to 0253 Catalysts were developed that utilized vanadium a Substrate as described above comprising a catalyst. Any compounds other than V.O.s, for example silver or copper number of catalysts can be used with the substrate to form a Vanadates. An example copper Vanadate base metal catalyst catalytic Substrate. The catalyst may be coated onto the Sur was developed by Heraeus (Strutz 1989). The catalyst can be face of the substrate. That is, the catalyst, in one embodiment, prepared by doping and calcining copper Vanadate CuVOs is adsorbed onto the surface (e.g., the walls of the channels) of with potassium carbonate in the molar ratio Cu:V: K about the catalytic substrate. Catalyst could also reside on the inside 3:2:0.13. The catalyst loading was between 10 and 80 g/m of of the core of the substrate and attached to the individual the filtration surface area. Another suitable catalyst is fibers of the substrate. In certain embodiments, the present Cu/ZSM5, which can be used as a DeNox catalyst. invention can function at the same or better levels compared 0254 Precious metals such as platinum, palladium, and to current technology but require a smaller amount of cata rhodium are the most common and are preferred, although lyst. other catalysts known in the art can be used. These three 0247. In another embodiment, the catalyst is deposited precious metals have been known as excellent and highly only on the channel wall Surfaces and not inside the channel efficient catalysts with internal combustion engine emissions. walls. In another embodiment, the catalyst is deposited on the In over twenty-five years of catalytic converters, there has not ingress channel walls, on the egress channel walls, within the really been a meaningful substitute for this trinity. However, walls, or combinations thereof. In yet a further embodiment, there are thousands of combinations of these catalysts con a first catalyst lines, coats, or permeates a beginning, or proxi figured according to the original equipment manufacturer, mal, portion of the channel wall; a second catalyst lines, vehicle, vehicle load, environmental regulations, engine, coats, or permeates a middle portion of the channel wall; and transmission, etc. Throughout the truck and automotive yet a third catalyst at a terminal section of the channel wall. manufacturing industry, various combinations and formula 0248. In one embodiment, the catalytic substrate of the tions of catalysts are employed. A catalytic Substrate accord present invention preferably contains a catalytic metal. In ing to the present invention comprises any one or more of another metal, the catalytic Substrate does not contain a cata these catalyst combinations. Many combinations are consid lytic metal. However, under certain conditions, the substrate ered proprietary material. Manufacturers such as Ford, GM, is able to catalyze suitable reactions without the need for a and Toyota have a unique catalyst formula for each vehicle, separate catalytic metal, for example, in certain embodi due to the varying vehicle weights and engine performance ments, a washcoat as described below may function as a demands. Manufacturers also have different catalyst formu catalyst. las for the same vehicle depending upon where the vehicle 0249. Any catalyst capable of being applied to the sub will be sold or licensed, e.g., Canada, United States, Califor strate can be used. Such a catalyst includes but is not limited nia, Mexico. Currently, these formulations may change two to to platinum, palladium (such as palladium oxide), rhodium, three times per vehicle per model year, due to the strict gov US 2008/01 12865 A1 May 15, 2008 22 ernmental regulations. For these reasons, most manufacturers 0263 For example, the substrate of the present invention handle the application of the catalytic coatings themselves. can be used in a catalyzed diesel particulate filters (CDPF). A 0255. In a further embodiment, the catalytic substrate CDPF utilizes catalysts deposited directly on the substrate. comprises a nSiRFC and a catalyst that is used in a commer Both precious and base metal catalysts can be used, such as cially available catalytic environment. platinum, silver, copper, Vanadium, iron, molybdenum, man 0256 In one aspect, once the substrate has been shaped to ganese, chromium, nickel, derivatives thereof (such as its final dimensions and a washcoat is applied and cured, one oxides) and others. Depending on the type of filter, the cata or more catalysts are applied using known techniques and lyst can be impregnated directly into the media or an inter methods, such as the manner of applying a palladium-plati mediate washcoat layer can be used. A CDPF can utilize num based catalyst as disclosed in U.S. Pat. Nos. 5.244.852 exhaust temperatures of about 325-420° C. for regeneration, and 5.272,125, the teachings of which are both incorporated depending on engine technology (PM emissions) and fuel herein by reference in their entirety. quality (Sulfur content). 0257. In one embodiment, the catalyst is in an amount 0264. Platinum is one of the most active and most com sufficient for the catalytic action to take place effectively. For monly used noble metal catalysts, but palladium, rhodium, or example, the amount Sufficient, in one embodiment, refers to ruthenium catalysts, usually in mixtures, are also suitable for an amount of catalyst, e.g., a precious metal, interacting with use in the present invention. The list of common non plati and in the path of the emission sufficient to react with as much num-group metals used in catalytic converters includes vana of the emission as possible, such as 80%, 85%, 90%, 95%, dium, magnesium, calcium, strontium, barium, copper and 97%, 98%, and 99%, and the like. silver. In one embodiment, platinum is the preferred catalyst 0258. In one embodiment, the catalyst is deposited on or for use with diesel engines. In another embodiment, palla impregnated into the washcoat, preferably as individual crys dium and rhodium Suitable for use with a gasoline engine. tals. In this embodiment, the catalysts are not applied as a 0265 Catalysts are typically quite expensive. It is there Veneer-like coating over the washcoat (like paint on a wall). fore desirable to achieve the maximum reduction in pollution When the catalysts are impregnated onto the washcoat, they with the minimum amount of catalyst used. Platinum and are applied so the end product is partially or Substantially a palladium, two common catalysts, are both expensive pre colony of individual crystals. This can be visualized as salt cious metals. A substrate having a porous, permeable nature crystals on a pretzel. It is preferable that Sufficient spacing is with a large Surface area on which catalysts can reside as provided between the catalysts. At the same time, there evenly distributed crystals or layer allow for achieving that should be enough precious metals in the fluid path, e.g., the objective. An advantage of the present invention is a lower exhaust path, at the optimum catalytic activity operating tem amount of catalyst needed compared to conventional Sub perature, i.e., light off, and the precious metals must fit within Strates. the physical restraints, i.e., space, permitted by the function 0266 Typical platinum loadings infilters used for off-road ality and design of a vehicle and engine. engines through the 1990's were between 35 and 50 g/ft. 0259. A manufacturing goal is to maximize the pollutants These filters, installed on relatively high polluting engines, removed while minimizing the amount of catalyst required on required minimum temperatures of nearly 400° C. for regen the substrate. Each vehicle produces a different amount of eration. Later, when catalyzed filters were applied to much pollutant, and as such, the Substrate is in Some embodiments cleaner urban bus and other highway vehicle engines, it was customized to address that level of pollutants and minimize found that the catalyzed filters were able to regenerate at the amount of precious metals. much lower temperatures. However, higher platinum load 0260. In another embodiment, the catalyst addition to the ings were needed to Support the low temperature regenera catalytic Substrate can occur during the slurry process when tion. Filters used in clean engine, low temperature applica making of the Substrate, or it can occur after the machining tions have typically platinum loadings of 50-75 g/ft. process (as described below). In this case, the catalyst is 0267 In one embodiment, the catalytic substrate com mixed with the slurry of fibers prior to any heating step. prises a catalyst in the amount of about 1 to about 100, about 0261 Single and multiple catalyst formulations can be 1 to about 50, about 1 to about 30, or about 10 to about 40 applied to a single Substrate, or due to the Small size of the g/ft. filter relative to the existing catalytic converters and exhaust 0268. In another embodiment, the catalytic substrate, pref systems, the placement of multiple Substrates is possible. erably an nSiRF-C such as AETB, OCTB, and FRCI, com Thus, the catalytic substrate of the present invention in one prises catalyst of platinum and rhodium in a ratio of about 5:1 embodiment comprises or consists of or consists essentially and an amount of about 30 g/ft. of one or more Zones, wherein each Zone has a different catalyst. Alternatively, one or more of the Zones may be Filtering Substrate uncatalyzed. For example, a catalytic Substrate of the present 0269. The present invention is directed to a catalytic sub invention may include an oxidation catalyst in one Zone strate comprising a non-woven Sintered Refractory Fibrous which contains the front surface of the substrate, and a reduc Ceramic (nSiRF-C) composite, as described herein, that can ing catalyst in another Zone which contain the rear Surface. be used in particulate filters, and related devices. The filtering 0262. If the substrate is to be used as a flow through con Substrate is fashioned into particular shapes, designs, sizes, figuration, then it is preferable, although not required, for the and configurations that are useful for filtering, in particular catalysts, or the majority of the catalysts, to reside along the for filtering particulate matter. The filtering substrate is par surface of the channels. If the substrate is machined into a ticularly useful for filtering particulate matter under extreme wall flow configuration, then it is preferable for the catalysts conditions (temperature, pressure, etc), such as filtering a to be evenly distributed throughout the substrate as the gases flow of exhaust gas. The filtering substrate can be used in are going to be traveling through all of the Substrate and not additional applications in which the filtering of Small particu just passing through. late matter is required. US 2008/01 12865 A1 May 15, 2008

0270. In one embodiment, the filtering substrate com wheeled motorcycle (e.g., motorized tricycles, autorichs prises, or alternatively consists of or consists essentially of a haws), motorized tricycles; heavy-duty highway engines, nSiRF-C composite as described above for the catalytic sub such as trucks and buses; 2) Mobile Non-Road Engines, strate. The filtering Substrate does not contain a catalyst. All Equipment, and Vehicles, including compression-ignition variations, embodiments, and examples of materials suitable engines (farm, construction, mining, etc.); Small spark-igni for use as the substrate of a catalytic substrate are likewise tion engines (lawn mowers, leaf blowers, chainsaws, etc.); suitable for the filtering substrate of the present invention. large spark-ignition engines (forklifts, generators, etc.); 0271 The filtering substrate is shaped into configurations marine diesel engines (commercial ships, recreational diesel, suitable for uses described herein, in particular for use in etc.); marine spark-ignition engines (boats, personal water particulate traps Such as diesel particulate traps and diesel craft, etc.); recreational vehicles (snowmobiles, dirt bikes, particulate filters. all-terrain vehicles, etc.); locomotives; aviation (aircraft, 0272. In one embodiment, a filtering substrate of the ground Support equipment, etc.); and 3) Stationary Sources, present invention is alumina enhanced thermal barrier including hundreds of Sources, such as power plants, refiner (AETB) material or a like material known to one of ordi ies, and manufacturing facilities. nary skill in the art. AETB is made from aluminaboriasilica 0281. In another embodiment, a catalytic substrate of the (also known as alumina-boria-silica, aluminoborosilicate, present invention is suitable for use in a particular vehicle if and aluminoboriasilicate) fibers, silica fibers, and alumina the substrate as described herein, when a part of a catalytic fibers. One commonly known application for AETB is as an converter, functions so that the vehicle meets the emissions exterior tile on the Space Shuttle, ideal for shuttle re-entry. standards of any one of 1990, 2007, and 2010, as defined by The attributes that make AETB unique and desirable to the the EPA. space industry are also preferred in organic combustion tech 0282. In another embodiment, the catalytic substrate cata nology. AETB has a high melting point, low heat conductance lyzes the reaction of pollutants to nonpollutants at a high and coefficient of thermal expansion, ability to withstand level. For example, the conversion of pollutants to nonpollut thermal and vibrational shock, low density, and very high ants is catalyzed at an efficiency of greater than 50%. In porosity and permeability. another embodiment, the conversion of pollutants to nonpol 0273. The filtering substrate of the present invention is lutants is catalyzed at an efficiency of greater than 60%. In optionally treated with one or more chemical additives. still other embodiments, the conversion rate is selected from 0274. In another embodiment, the present invention is the group consisting of 70%, 80%, 90%, 91%, 92%, 93%, directed to a diesel particulate trap comprising a filter as 94%. 95%, 96%, 97%, 98%, 99%, and 99.9%. In certain described herein without any catalyst applied to it. embodiments, the conversion rate refers to the total conver 0275. In another embodiment, the present invention is sion of non-particulate pollutants. In other embodiments, the directed to a diesel particulate trap comprising a filter as conversion rate refers to the conversion of specific non-par described herein in combination with a CRTR diesel particu ticulate pollutants, e.g., NOx to N. CO to CO. or HCs to late trap (NOX, HC adsorbers). CO, and H.O. In other embodiments, the conversion rate 0276. In another embodiment, the present invention is refers to the percentage of particulate matter removed from an directed to a diesel particulate trap comprising a filter as exhaust gas. described herein in combination with SCR. 0283. In another embodiment, a catalytic substrate of the 0277. In another embodiment, the filtering substrate com present invention is suitable for use in a particular application prises a plurality of channels as described in more detail if the catalytic substrate passes certain OEM-prescribed and below. Furthermore, the filtering substrate can be modified, preferred tests, such as U.S. Federal Test Protocol 75 (U.S. altered, and/or enhanced in one or more aspects as described FTP75). Such tests are known in the art. (See for example herein and/or as known in the art. Document No. EPA420-R-92-009, published by the U.S. EPA, available at http://www.epa.gov/otaq/inventory/ Attributes of a Catalytic and Filtering Substrates r92009.pdf, which is herein incorporated by reference in its entirety). Additionally, as a back-cat or DPT in retrofit appli 0278. The present invention has one or more, preferably at cations, EPA and/or state/local agencies may have to approve least three, four, five, six, seven, eight, nine, or ten, attributes of the products for use, including the Substrate contained which are advantageous over conventional catalytic or filter therein. ing Substrates. 0284 Surface Area 0285. The available surface area of a substrate is an impor Suitable for Use tant characteristic of filtering Substrate or catalytic Substrate. 0279. The invention is directed in certain embodiments to One characteristic of a suitable substrate for a catalytic con a catalytic Substrate or filtering Substrate comprising verter is for it to have a high geometric surface area (GSA). nSiRF-C and a catalyst, suitable for use in a catalytic con The high GSA allows for maximum reaction probability. verter. The substrate is suitable for use in any number of 0286 A large open frontal area (OFA) allows for greater catalytic converters, filtering devices and applications amount of gas to pass through without obstructing its flow and thereof. causing back-pressure. Open frontal area (OFA) is defined as 0280 For example, the catalytic substrate and filtering the part of the total substrate cross-section area which is substrate of the present invention is suitable of use in any of available for the flow of gas (i.e., the cross-section area of the the applications generally used for prior art Substrates. Suit filter inlet channels). It is typically expressed relative to the able uses include, but are not limited to, the use of a substrate total Substrate cross-section. of the present invention in an exhaust system any 1) Mobile 0287. An attribute of the substrate of the present invention On-Road Engines, Equipment, and Vehicles, including cars is its high surface area or high GSA. The surface area of the and light trucks; highway and street motorcycles, three Substrate is an important characteristic for catalysis applica US 2008/01 12865 A1 May 15, 2008 24 tion. Surface area is the Sum amount of Surface that exhaust lyst systems (as opposed to the simple catalysts used in the emissions must pass across when traveling through an 1990's, which often had very little or no washcoat material). exhaust filter. Increased surface area translates into an The substrates should have acceptably low pressure loss after increased surface for chemical reactions to take place being coated with catalyst/washcoat systems at about 50 between pollutants and catalytic and thermal processes, mak g/dm loading. Certain prior art filters have a porosity of about ing a catalytic converter process quicker and more efficient. 45-55% range. Additional heaters may also be applied. Speed and efficiency can result in little to no clogging, which 0297 Filter/NOx adsorberdevices, such as the DPNR sys can cause failure of the exhaust system. Furthermore, the tem or CRT (continuous regeneration trap) incorporate NOx increased surface area of the substrate of certain embodi storage/reduction systems and require high washcoat load ments also includes increased filtering efficiency and/or capa ings, possibly above 100 g/dm. Certain prior art substrates bility. have a porosity of about 60% (a 65% porosity substrate has 0288 Geometric surface area is the total surface area that been reported, with mechanical strength being the main limi precious metals can be impregnated onto in one cubic inch. A tation in increasing porosity (Ichikawa, S., et al., 2003, Substrate having a high gross Surface area is preferred. Certain “Material Development of High Porous SiC for Catalyzed embodiments of the present invention have a much higher Diesel Particulate Filters.” SAE 2003-01-0380). geometric Surface area that can be impregnated with catalyst, 0298 Another attribute of certain embodiments of the compared to conventional Substrates, such as cordierite and catalytic or filtering Substrate of the present invention is its SiC. high porosity. In certain embodiments, the porosity of a Sub 0289 Gross wall volume is the total amount of wall vol strate of the present invention is from about 60%, 70%, 80%, ume that exists in a one inch cube of configured Substrate. or 90%. In other embodiments, the substrate has a porosity of Gross wall Volume is calculated as each wall Surface area about 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% multiplied by each respective thickness and Summed. A Sub (expressed as a percent of pore space relative to the solid strate having a lower gross wall Volume is preferred. In certain substrate). embodiments, the gross wall volume of the substrate of the 0299. In one embodiment, the porosity of an exemplary present invention is lower than that of conventional substrate embodiment of the present invention is approximately materials, such as cordierite and sic. 97.26%. By comparison, cordierite is about 18-42%. In this 0290. In certain embodiments, the gross wall volume of embodiment, the material of the present invention only has the catalytic substrate is from about 0.5 to about 0.1, from about 2.74% material to obstruct the flow of exhaust gas. This about 0.4 to about 0.2, or about 0.3 in/in (cubic inches per fine web of material actively catches the particulate and burns cubic inch). In a preferred embodiment, the gross wall vol it off very effectively. Due to the trapping of particulates in ume substrate is about 0.25 to about 0.28, more preferably depth filtration mode and not only along channel walls, con about 0.27, more preferably about 0.272 in/in. siderable PM buildup does not occur under situation where 0291 Due to the lower gross wall volume of the present regeneration time is longer than PM build-up time. High invention in certain embodiments, a lower amount of catalyst, porosity translates into better and more effective interaction Such as palladium, is needed to perform the catalytic action between pollutants and the catalyzed or non-catalyzed Sub with the present invention than a cordierite of a similar size. strate surface. At the same time, gas flow buildup can be 0292 Porosity and Permeability released laterally as well as along the intended gas flow direc 0293 Pore attributes also affect mechanical and thermal tion. attributes of the substrate. A trade-off can exist between (0300 Referring to FIGS. 22a and 22b, an exemplified porosity and mechanical strength: Substrates of Smaller pore substrate 2200, 2205 of the present invention is shown. Sub size and lower porosity are stronger than those of higher strate 2200, 2205 is approximately ninety-seven percent porosity for certain conventional Substrates. Thermal porous. As compared to the samples of cordierite in FIGS. 2a attributes, both specific heat capacity and thermal conductiv and 2b and silicon carbide in FIG. 3, all being substantially ity may decrease with increasing porosity in certain materials the same scale, substrate 1200, 1205 is more porous and less (Yuuki 2003). dense. In FIG.22b, particular matter PM-102210 and PM-2.5 0294 The first wall-flow monoliths, introduced in the late 2225 is illustrated to scale. The particulate matter PM-10 1980's, had channels as large as 35um in diameter. In order to 2210 and PM-2.5 2225 can easily permeate the fibers of maximize filtration efficiency, channels were made Smaller, substrate 2205, as compared to the cordierite sample 205 typically in the range of 10-15um infilters used in the 1990's. exemplified FIG. 2b. Also, compared to the silicon carbide In the development of new materials, filter manufacturers 300 of FIG. 3, the density of silicon carbide is about thirty to differentiate their target pore attributes, primarily in consid fifty times that of substrate 2200, 2205. eration of the catalyst system to be applied (Ogyu, K., et al., 0301 The higher porosity in certain embodiments of the 2003. “Characterization of Thin Wall SiC-DPF, SAE 2003 present invention provides a higher Surface area and lowers 01-0377:Yuuki, K., et al., 2003, “The Effect of SiC Properties the backpressure. As a result, the present invention is more on the Performance of Catalyzed Diesel Particulate Filter efficient at NOx reduction, hydrocarbon and CO oxidation, (DPF).” SAE 2003-01-0383). The applications can be classi and particulate matter trapping. fied as follows: 0302 Pore characteristics, including volume percent 0295 Non-catalyzed filters, such as those used in fuel porosity, size distribution, structure, and interconnectivity additive regenerated systems: The main requirement is a high determine the monolith ability to filterparticulates. Addition Soot holding capacity. Certain conventional filters have a ally, if gas molecules can diffuse into a porous Substrate, the porosity that is about 40-45% with pores between 10-20 um. probability of a catalytic reaction increases dramatically. 0296 Catalyzed filters, such as those in passively regen Together with the cellular geometry, porosity characteristics erated systems require more porosity and possibly larger pore also influence the monolith's hydraulic resistance to flow and size to enable coating with increasingly more complex cata the pressure drop. Some attributes which are desired for high US 2008/01 12865 A1 May 15, 2008 filtration efficiency (e.g., low porosity and Small pore size) are 0309. By comparison, a sample of cordierite is about 1.3 to opposite to those required for low pressure drop. Others. Such 1.8 W/m-K. These results indicate that, by way of example of as good pore interconnectivity and absence of closed, “dead a particular embodiment, if 1000 Watts of heat energy is lost end’ pores, are desired for both low pressure drop and high from a given volume of cordierite material, only 33 Watts efficiency. The substrates of the present invention in another would be lost from the same volume of the material from the embodiment provide both high filtration efficiency and low present invention. Thus, the material of the present invention pressure drop. has athermal conductivity thirty times greater than cordierite. 0310. Additionally, in other embodiments, the process of 0303 Emissivity and Heat Conductance preparing the Substrate further comprises preparing a cata 0304 Another property of substrates used in catalytic con lytic Substrate or filtering Substrate further comprising an verters and particulate filters is emissivity. Emissivity is the emissivity enhancing agent, said process comprising apply tendency to emission heat; comparative facility of emission, ing an emissivity enhancing agent to said Substrate, prefer or rate at which emission takes place, as of heat from the ably to a nSiRF-C, more preferably an AETB, OCTB, or surface of a heated body. FRCI material. Other preferred substrates include any of the 0305 An ideal substrate takes into consideration the tem specific substrates disclosed herein. In further embodiments, perature that (1) the fastest ramp-up to high conversion effi the catalytic Substrate further comprises an emissivity ciency; (2) is safest from thermal harm (e.g., due to thermal enhancing agent and a catalyst selected from the group con shock or due to high-temperature melting/cracking of Sub sisting of palladium, platinum, rhodium, derivatives thereof, strate); (3) uses a minimal amount of auxiliary energy; and (4) and mixtures thereof. Other physical and chemical modifica is inexpensive to produce. Increasing temperature requires tions as described herein can be applied to Such embodiments. additional energy and expense. Further, certain amounts of Emissivity enhancing agents are known in the art. the energy source are conducted, drawn, or channeled away 0311. Thermal Attributes through thermal conductivity. 0312. A substrate having a low coefficient of thermal 0306 Emissivity is a ratio of reflectance with values expansion allows for the Substrate to withstand rapid changes between 0 and 1, with one being perfect reflection. Different in temperature without significant expansion or contraction. substrates used for catalytic converters and particulate filters A suitable coefficient of thermal expansion also allows for the have different emissivity values. High emissivity allows the substrate to expand with heat at the same rate as the protective catalyst Substrate to minimize heat transfer out of the system, matting around it and the canister. thereby heating the air inside the catalytic converter or par 0313. It is also preferable for the substrate material to ticulate filter faster. The emissivity is a measure of the heat withstand a high range of temperatures so that it does not reflectance property of the material and a high value is desir cause a catalytic converter or particulate filter meltdown if the able. temperature rises to a high value, for example, during occa 0307. In certain embodiments, a substrate of the present sional fuel burning. Additionally, if the substrate material can invention preferably has an emissivity of about 0.8 to 1.0. In withstand high temperatures, the catalytic converter or filter another embodiment, the emissivity of the substrate of the can be placed closer to the engine. present invention is about 0.82, 0.84, 0.86, 0.88, and 0.9. 0314 Related properties include low thermal mass and Further suitable values for emissivity of a substrate of the heat capacity. A material that has a low thermal heat mass and present invention include 0.81, 0.83, 0.85, 0.87, and 0.89. In heat capacity allows for less heat energy to be wasted in other embodiments, the emissivity is about 0.9, 0.92, 0.94. raising the temperature of the catalyst Substrate. If the catalyst 0.96, or 0.98. Reflectivity of heat allows the gaseous material Substrate heats up quickly, more of the heatenergy coming via in the pores to heat up much faster since little heat is retained the exhaust gas is used to trigger the light-off of the catalyst by the substrate material itself. That results in quicker lightoff components. and little temperature rise of the outside surface of the sub 0315. Thermal conductivity is the capability of the mate Strate. rial to conduct heat as a consequence of molecular motion. 0308 The thermal conductivity of a material is the quan More specifically, thermal conductivity is also a measure of tity of heat that passes in unit time through unit area of a plate, the quantity of heat that passes in unit time through unit area when its opposite faces are subject to unit temperature gradi of a plate whose thickness is unity, when its opposite faces ent (e.g., one degree temperature difference across a thick differ in temperature by one degree. The more a material ness of one unit). Thermal conductivity has the units of Watts conducts heat, the more energy is needed to overcome loss of energy per meter thick and Kelvin changed (W/m-K). In and reach the required temperature. Preferably, a material preferred embodiments, the substrate of the present invention reflects heat, rather than conducts. A lower thermal conduc have a low thermal conductivity. For example, in one embodi tivity value is preferred so more heatenergy is utilized in the ment, the thermal conductivity of a substrate of the invention pore spaces and not lost from the absorption by the Substrate. is less than about 0.1, 0.2,0.3, 0.4,0.5,0.6,0.7, 0.8, or 0.9. In The chemistry of different substances determines the level of another embodiment, the thermal conductivity of a substrate thermal conductivity. Additionally, the thermal conductivity of the invention is less than about 0.01, 0.02, 0.03, 0.04, 0.05, of the filter medium is a major influence on the efficiency of 0.06, 0.07, 0.08, or 0.09. In another embodiment, the thermal an exhaust emission filter, since loss of temperature nega conductivity of a substrate of the invention is from about 0.1 tively impacts reactivity. A low thermal conductivity is pre to about 0.01, from about 0.2 to about 0.02, from about 0.3 to ferred because more of the heat energy generated is reflected about 0.03, from about 0.4 to about 0.04, from about 0.5 to back at the particulates, and will remain in the pore space. In about 0.05, from about 0.6 to about 0.06, from about 0.7 to other words, the lower the thermal conductivity, the lower the about 0.07, from about 0.8 to about 0.08, or from about 0.9 to loss of heat. Lowerheat loss translates into less energy needed about 0.09. In another embodiment, the thermal conductivity to obtain the desired temperature range for catalytic conver of the present invention is approximately 0.0604W/m-K. sion and higher energy efficiency. US 2008/01 12865 A1 May 15, 2008 26

0316 Specific heat is the heat in calories required to raise C., 2300° C., 2400° C., 2500° C., 2600° C., 2700° C., 2800° the temperature of one gram of a Substance one degree Cel C., 2900° C., 3000° C., and 3100° C. sius. A substrate with a high specific heat will reflect ambient 0322 The multiple use temperature limit of an exemplary heat, e.g., from an exhaust or an auxiliary source, back into embodiment of the present invention is 2.980 degrees Cel the pore space where combustion or catalytic reduction and sius. A sample of cordierite is about 1,400 degrees Celsius. oxidation processes require the heat. For instance, under The embodiment of the present invention can withstand more extreme conditions, e.g., the Arctic, it will take longer to heat than twice the temperature than cordierite before breaking up a low specific heat filter and cool hot filters, increasing the down. This permits the material to function in a greater range chance for external heat damage. A lower specific heat is of exhaust environments. preferable because is reaches operating temperature faster 0323. The coefficient of thermal expansion is a ratio of the increase of the length (linear coefficient), area (Superficial), or and with less energy. Volume of a body for a given rise in temperature (usually for 0317. In certain embodiments, a substrate of the present Zero to one degree Celsius) to the original length, area, or invention has a number of preferred thermal attributes. Pref volume, respectively. These three coefficients are approxi erably, the material is such that heating of the air in the pore mately in the ratio 1:2:3. When not specifically expressed, the space occurs preferentially compared to the heating of the cubical coefficient is usually intended. The less a substrate substrate. Preferably, the substrate of the present invention will expand when heated, the less chance of leaking, fractur has a high melting point, and in certain embodiments, a higher ing, or damage to filter assembly. A lower thermal expansion melting point than conventional Substrates. A high melting is preferred to ensure that the Substrate keeps its dimensions point is preferred, in part, due to the extreme temperatures to even when heated or cooled. which a catalytic Substrate or filtering Substrate is exposed. 0324. The coefficient of thermal expansion for an exem 0318. In a preferred embodiment, a substrate of the present plary embodiment of the present invention is approximately invention preferably has a high melting point. In one embodi 2.65x107 W/m-K (Watts per meter Kelvin). A sample of ment, the melting point is greater than about 1500°F. In cordierite is about 2.5x10 W/m-K to 3.0x10 W/mK. The another embodiment, the melting point is greater than about thermal expansion of a material of the present invention is less 2000°F. In another embodiment, the melting point is greater than ten times that of cordierite. than about 2500 F. In a further embodiment, the melting 0325 The coefficient of thermal expansion of the substrate point of the substrate is about 2000 to about 4000° F. In a is preferably compatible with the coefficient of thermal further embodiment, the melting point of the substrate is expansion of any washcoat. about 3000 to about 4000° F. Other suitable melting point 0326 In one embodiment, a catalytic or filtering substrate ranges include from about 3000 to about 3100, from bout of the present invention, compared to certain prior art Sub 3100 to about 3200, from about 3200 to about 3300, from strates such as cordierite, has an increased resistance to dam about 3300 to about 3400, from about 3400 to about 3500, age by thermal or mechanical stress; has a lower risk of from about 3500 to about 3600, from about 3600 to about clogging with soot and/or ash; is more tolerant to additive ash 3700, from about 3700 to about 3800, from about 3800 to accumulation when used with fuel additive regeneration; and about 3900, and from about 3900 to about 4000. In another has good efficiency for particle number reduction. preferred embodiment, the Substrate has a melting point of 0327 Density approximately 3632 degrees Fahrenheit. 0328. When considering substrates to be used in catalytic 0319. In one embodiment of the present invention, the converters or diesel particulate filters, it is preferable to use a Substrate has a melting point of approximately 3,632 degrees substrate that has a low density. The material having a low Fahrenheit. For example, if a vehicle is situated in below density reduces the weight of the substrate and hence the freezing temperatures, a blast of 1,500 degree Fahrenheit overall weight of the vehicle. Furthermore, low density is exhaust fumes will not cause the Substrate to crack or fracture. complimentary to high porosity and permeability Similarly, certain embodiments of the substrate will not over 0329. Higher density translates into a higher weight. heat and crack. Certain samples of cordierite have a melting Weight is a large factor pertaining to any engine in motion. point of about 1,400 degrees Celsius. The heavier the part, the more energy is needed to move it. In 0320. The specific heat of an exemplary embodiment of order for these filters to accommodate the increased volume the present invention is approximately 640J/kg-K (Joules per of particulate generated by a engine, the filter sizes have to kilogram-Kelvin). A sample of cordierite is about 750J/kg-K. increase, which adds to vehicle weight and manufacturing Even though the cordierite has a greater specific heat, cordi and operating costs. Thus, a lower density material is desired. erite filters have a greater mass to heat up. The result is more Of course, the density is not so low that structural integrity is heat energy is needed to reach operating temperature making insufficient. the cordierite less efficient. 0330. Another attribute of the substrate of the present 0321) A multiple use temperature limit is the maximum invention is its density. The density of the substrate is lower temperature in which a Substance can be subjected a plurality than that of certain conventional filters and substrates used for of times without substantial degradation. The higher the tem filtering and as catalytic Substrate. Density is the ratio of mass perature a substrate can continue to operate without micro of a portion of matter to its Volume. Greater density requires fractures or spallation, the less chance of the substrate break more energy to reach operating temperature. In other words, ing or cracking over time. This in turn means the Substrate is more energy is needed to heat up a dense material than a less more durable over a wider temperature range. A higher mul dense material. For materials with the same specific heat, tiple use temperature limit is preferred. A suitable multiple greater density directly translates into greater weight for set use temperature limit for certain embodiments of the catalytic volume. Weight is detrimental to a vehicle's mileage and or filtering substrates of the present invention is one selected performance, as the engine must work harder to move heavier from the group consisting of about 2000°C., 2100° C.,2200 equipment. Increased density also translates into more heat US 2008/01 12865 A1 May 15, 2008 27 required to achieve the proper temperature for catalytic activ their location during normal wear and tear of the system. ity or “light off to occur. The density of some materials Good coatability and washcoat compatibility also enhances currently used as Substrates or filters are higher than optimal. the long-term effectiveness of the catalytic converter system. For example, a sample of cordierite is about 2.0 to 2.1 g/cm. Good coatability and washcoat compatibility also increases Thus, there is a need for a substrate and a filter having a lower the lifetime of the catalyst. density. The density of the substrate of the present invention 0338 Another attribute of the substrate of the invention is is lower than that of cordierite. its structural integrity. Structural integrity of a material may 0331. In one embodiment, the catalytic substrate of the be measured by the material's tensile modulus. Tensile modu present invention preferably has a low density. The density of lus is a material's resistance to rupture. Specifically, the the substrate of the present invention may be in the range from greater longitudinal stress a material can bear without tearing about 2 to about 50 pounds per cubic foot (1b/ft). In a pre asunder. Tensile modulus is usually expressed with a refer ferred embodiment, the density of the substrate is in the range ence to a unit area of cross section, the number of pounds per of about 5 to about 30 pounds per cubic foot, more preferably, square inch, or kilograms per square centimeter necessary to from about 8 to 16 pounds per cubic foot. Other preferred produce rupture. Tensile modulus is relevant in whether the embodiments include catalytic Substrate that has a density of substrate can withstand the force generated by violent, about 8, 9, 10, 11, 12, 13, 14, 15, or 16 lb/ft. A low density exhaust gas flow pressure. that still imparts structural integrity is preferred. 0339. A catalytic substrate according to the present inven 0332. In one embodiment, the substrate of the invention tion preferably has a higher tensile modulus. For example, in has a density of about 8 lbs/ft and 22 lbs/ft, preferably from one embodiment, the Substrate of the present invention has an about 8 lbs/ft and 22 lbs/ft. In another embodiment, the axial strength of about 2.21 MPa. Of course, higher axial substrate comprises AETB-8 or AETB-16, having densities strengths are suitable as well. Other suitable values include 1, of about 8 lbs/ft and about 16 lbs/ft respectively. Other 2, 3, 4, 5, 6, 7, 8, 9 and 10 MPa. suitable densities include a density selected from about 9, 10. 0340 Furthermore, structural integrity of the catalytic 11, 12, 13, 14, 15, and 16 lbs/ft. substrate of the invention is such that it can withstand the 0333. In another embodiment, the density of the substrate conditions encountered during its use in a catalytic converter is approximately 0.10 to approximately 0.25 g/cm (grams in commercial vehicles. per cubic centimeter). 0341. In another embodiment, the substrate of the inven 0334 Structural Integrity tion, e.g., nSiRF-C, preferably has a high structural integrity 0335 The structural integrity of the substrate material is a and a low density. characteristic that is important to consider. Structural integ 0342. Reduction of Pollutants rity refers to the material's ability to withstand vibrational and mechanical stresses, i.e., shake and bake. For example, Sub 0343. The substrate plays an important role in enhancing strate strength is important for withstanding packaging loads the catalytic activity of the catalyst materials coated on it. and Subsequent use in the engine exhaust stream with the Additionally substrates are used to trap particulate material related exposure to various stresses, including engine vibra which is then burnt off as volatile gases. tions, road shock, and temperature gradients. High-strength 0344 Another advantage of the substrate of the present substrates are desirable for robust catalytic converter systems invention is its increased ability to reduce the amount of and particulate filters. The strength of the substrate material pollutants in an exhaust gas. The present invention has may be controlled by the type of intra- and intercrystalline enhanced catalytic and filtering capabilities as compared to bonding, the porosity, pore size distribution, and flaw popu certain conventional technologies. lation. Additionally, substrates can be strengthened by the 0345. In certain embodiments, the substrate of the present application of chemical/material coatings on the inside of invention is capable of reducing CO emission from an exhaust outside. The strength of the cellular structure of the substrate gas by at least about 50%. In one embodiment, the substrate of may further determined by its dimensions, cross-sectional the present invention is capable of reducing CO emission symmetry, and its cellular attributes, such as cell density, from an exhaust gas by at least about 60%, 70%, 80%, or 90%. channel geometry, and wall thickness. Substrate strength In another embodiment, the Substrate is capable of reducing must exceed the stress to which the material is exposed during CO emission by at least 91%, 92%, 93%, 94%, 95%, 96%, both packaging and operation. If the stress exceeds the 97%, 98%, 99%, 99.5%, 99.9%, or 100%. strength, the Substrate will crack. 0346. In certain embodiments, the substrate of the present 0336 Structural integrity of a material may be measured invention is capable of reducing NOx emission from an by the material's tensile modulus. Tensile modulus is a mate exhaust gas by at least about 50%. In one embodiment, the rial's resistance to rupture. Specifically, the greater longitu substrate of the present invention is capable of reducing NOx dinal stress a material can bear without tearing asunder. Ten emission from an exhaust gas by at least about 60%, 70%, sile modulus is usually expressed with a reference to a unit 80%, or 90%. In another embodiment, the substrate is capable area of cross section, the number of pounds per square inch, or of reducing NOx emission by at least 91%, 92%, 93%, 94%, kilograms per square centimeter necessary to produce rup 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, or 100%. ture. Tensile modulus is relevant in whether the substrate can 0347 In certain embodiments, the substrate of the present withstand the force generated by violent, exhaust gas flow invention is capable of reducing HC emission from an exhaust pressure. gas by at least about 50%. In one embodiment, the substrate of 0337 Additionally, a substrate should have a good coat the present invention is capable of reducing HC emission ability so that the washcoat and/or a catalytic coat can be from an exhaust gas by at least about 60%, 70%, 80%, or 90%. applied to the substrate. Likewise, the substrate should have In another embodiment, the Substrate is capable of reducing washcoat compatibility, allowing for the catalysts to mount HC emission by at least 91%, 92%, 93%, 94%, 95%, 96%, well onto the substrate so that catalysts are not displaced from 97%, 98%, 99%, 99.5%, 99.9%, or 100%. US 2008/01 12865 A1 May 15, 2008 28

0348. In other embodiments, the substrate of the present attenuate or dampen acoustic energy in engine exhaust. A invention is capable of reducing VOC emission from an Substrate of the present invention can replace or compliment exhaust gas by at least 50%. In one embodiment, the substrate an engine's muffler assembly, as disclosed herein, thus of the present invention is capable of reducing VOC emission decreasing exhaust noise and exhaust system costs. A higher from an exhaust gas by at least about 60%, 70%, 80%, or 90%. acoustic attenuation is preferred. In another embodiment, the Substrate is capable of reducing 0358. In another embodiment the porosity, density and VOC emission by at least 91%, 92%, 93%, 94%, 95%, 96%, size of the substrate may be varied to tune the acoustical 97%, 98%, 99%, 99.5%, 99.9%, or 100%. attenuation for desired applications. 0349. In other embodiments, the substrate of the present 0359. In another embodiment, the acoustical attenuation invention is capable of reducing PM-10 emission from an of the substrate maybe coupled with standard metal-muffler exhaust gas by at least 50%. In one embodiment, the substrate based techniques to dampen and/or tune the Sound existing of the present invention is capable of reducing PM-10 emis the exhaust system. sion from an exhaust gas by at least about 60%, 70%. 80%, or 90%. In another embodiment, the substrate is capable of Type of Flow reducing PM-10 emission by at least 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, or 100%. 0360 Flow-Through 0350. In other embodiments, the substrate of the present 0361. In one aspect, the substrate is structured for a flow invention is capable of reducing PM-2.5 emission from an through use. The flow-through configuration is known in the exhaust gas by at least 50%. In one embodiment, the substrate art. In one embodiment, the channels (or pores) are essen of the present invention is capable of reducing PM-2.5 emis tially aligned parallel to each other across the entire length of sion from an exhaust gas by at least about 60%, 70%. 80%, or the substrate. Gas flow enters the substrateatone end and runs 90%. In another embodiment, the substrate is capable of down the through the channels through the entire length of the reducing PM-2.5 emission by at least 91%, 92%, 93%, 94%, substrate to exit on the other side. 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, or 100%. 0362 Any number offlow-through configurations are use 0351 Reduced Weight ful and suitable for the catalytic substrate of the present inven 0352. It is a goal of the vehicle manufacturers to reduce the tion. Flow through configurations that are known in the art overall weight of the vehicle to improve its fuel economy and can be applied to the catalytic Substrate of the present inven engine efficiency. Heavy Substrates add unnecessary weight tion. to the vehicle. Additionally, if substrates are not efficient 0363. In one embodiment, the flow through configuration enough in reducing pollution, more than one Substrates may comprises a plurality of Substantially parallel channels that be required to play in line to reach target pollution levels. This extend fully through the length of the substrate. greatly enhances the overall weight of the vehicle. 0364. In another embodiment, the walls of the channels 0353. Additionally, current catalytic converters require are not parallel to the lateral or surface of the substrate. the use of additional devices which are often heavy and 0365 Wall-Flow clunky. Some of these devices, such as heat shields and par 0366 Another embodiment of the invention is a catalytic ticular matting, are used to deal with the temperature of the substrate or filtering substrate of the present invention con catalytic converter. Others, such as oxygen sensors, are figured in the wall flow configuration. It has been Surprisingly required to meet certain government regulations. determined that a catalytic substrate comprising an nSiRF-C 0354. In certain embodiments of the present invention, the of the present invention can be configured in the wall flow catalytic Substrate or filtering Substrate has reduced weight in configuration. comparison to a conventional catalytic or filtering Substrates. 0367. In another aspect of the invention, the substrate has This is due, in part, to the lower density of the substrate of the a wall-flow configuration. For example, the Substrate is used present invention compared to certain conventional Sub in a wall-flow catalytic converter or a wall-flow particulate strates. Alternatively, the lower weight may be due to the need filter. The wall-flow configuration can take any one of a num for a smalleramount of catalytic or filtering Substrate because ber of physical arrangements. A Substrate having a wall flow of the improved filtering and catalytic function of some configuration can have one or more the attributes described embodiments of the present invention compared to conven herein. Further, a Substrate having a wall flow configuration tional technologies. A lower weight of a catalytic or filtering may further comprise one or more of the following: a catalyst, substrate has a number of benefits. For example, a lower a washcoat, an oxygen-storing oxide, and an emissivity weight of a substrate may translate into improved fuel effi enhancer Additionally, a Substrate consisting of a wall flow ciency for vehicles. Furthermore, a lower weight would trans configuration may be further modified, enhanced, or altered late into easier to handle and possible safer handheld engine as described herein. devices. 0368. In one embodiment, the channel wall thickness is 0355. In a preferred embodiment, the exterior surface of any value described below. Preferred channel wall thickness the Substrate does not heat up to the same extent as conven from about 2 mils to about 6 mils. In other embodiments, the tional catalytic converter Substrates during use. In some channel wall thickness ranges from about 10 mils to about 17 embodiments, the need for a heat shield and/or insulation is mils. Other suitable values include 2,3,4,5,6,7,8,9, 10, 11, reduced. 12, 13, 14, 15, 16, 17, 18, 19 and 20 mls. 0356 Acoustical Attributes 0369. In other embodiments of the wall-flow substrate, the 0357 Acoustic attenuation may be defined as either the cell density of the substrate is about 400 cpsi (cells per square diminution of thickness, thinness, emaciation; diminution of inch) with a wall thickness of about 6 mils, or the cell density density; diminution of force or intensity; or weakening of is about 900 cpsi with a channel wall thickness of about 2 acoustic energy (Sound). In one embodiment of the present mils. Additional embodiments include those in which the cpsi invention, the acoustic attenuation is the Substrate's ability to is about 50, 100, 150, 200, 250, 300, or 350. US 2008/01 12865 A1 May 15, 2008 29

0370 Ceramic wall-flow monoliths, which are derived 0375. In specific embodiments of the present invention, from the flow-through cellular supports used for catalytic the wall flow configuration has half of the channels blocked. converters, became the most common type of diesel filter In another configuration, the Substrate of the invention has a Substrate. They are distinguished, among other diesel filter wall flow configuration wherein the blocking wall of the designs, by high Surface area per unit volume and by high channel is located at the beginning or end of a channel. In filtration efficiencies. Monolithic diesel filters consist of another configuration, the blocking wall is located at the many Small parallel channels, typically of Square cross-sec middle of a channel, or alternatively is located anywhere tion, running axially through the part. Diesel filter monoliths between the beginning and end of a channel. are obtained from the flow-through monoliths by plugging 0376. Additionally, any percentage of the channels may be channels. Adjacent channels are alternatively plugged at each included in a wall flow configuration, e.g., 10%, 25%, 50%, end in order to force the diesel aerosol through the porous 75%, 90%, 95%, etc. substrate walls which act as a mechanical filter. To reflect this Channels and Channel Openings flow pattern, the substrates are referred to as the wall-flow monoliths. Wall-flow monoliths are most commonly avail 0377. In one embodiment, the catalytic or filtering sub able in cylindrical shapes, although oval cross-section parts strate does not contain a plurality of channels extending are also possible for space constrained applications. through the length of the Substrate. In certain embodiments, the catalytic or filtering Substrate, given its porosity and per 0371 Wall-flow filter walls have a distribution of fine meability, does not need to have the channels placed in the pores which have to be controlled in the manufacturing pro Substrate for the Substrate to function in its intended uses, e.g., cess. Filtration mechanism on monolith wall-flow filters is a in a catalytic converter. Any potential back pressure is combination of cake and depth filtration. Depth filtration is relieved by the porosity and permeability alone by placing the the dominant mechanism on a clean filter as the particulates emissions in the path of a catalytic Substrate. If a membrane are deposited in the inside of pores. As the Sootload increases, configuration without channels is used, a preferred use is in a a particulate layer develops at the inlet channel walls and cake low flow-rate environment so as to reduce the chance of the filtration becomes the prevailing mechanism. Certain conven Substrate failing structurally. The thin membrane configura tional monolith filters have filtration efficiencies of about tion would preferably be used in a “low flow-rate” environ 70% of total particulate matter (TPM). Higher efficiencies ment Such as in a fireplace or possibly a powerplant. Here the can be observed for solid PM fractions, such as elemental flow rate is low and in some instances constant (powerplant). carbon and metal ash. It is understood, of course, that such a configuration is suit 0372 According to certain embodiments of the present able for use in other applications as well, including vehicles invention, it is preferred to have material which is porous so and stationary engines. more gases can pass easily through the pores, interacting with 0378. In another embodiment, a catalytic or filtering sub catalysts deposited in the core of the fibrous composite. Addi strate of the invention, in one embodiment, has a plurality of tionally, having porous walls allows in certain embodiments channels extending longitudinally through at least a portion for higher degree of depth filtration which would also be a of the substrate. The plurality channels allow a fluid medium, desirable attribute. e.g., a gas or a liquid, to flow through the Substrate. The 0373 Substrates of the present invention in a wall flow plurality of channels extend from the frontal surface towards configuration comes in much more direct contact with the the rear surface. Other channels may extend from the rear exhaust gas. Material pore characteristics (size, percent surface to the frontal surface. porosity, pore connectivity, open VS closed pores, etc.) influ 0379 The channels can extend through the entire length of ence the physical interaction between gas and filter material the Substrate. In Such an embodiment, a channel will have a and affect such attributes as filtration efficiency and pressure first channel opening on the frontal surface of the substrate drop. Furthermore, substrate durability depends on the mate and a second channel opening on the rear Surface. Alterna rial resistance to chemical attack by exhaust gas components. tively, a channel extends through a portion of the Substrate. In In particular, materials need to be resistant to corrosion by certain embodiments, the channel extends through about metalash which may be part of diesel particulates. Resistance 99%, 97%, 95%, 90%, 85%, 80%, 70%, 60%, or 50% of the to Sulfuric acid corrosion is also required, especially if filters length of the substrate. are used with fuels of higher sulfur content. Additionally, due 0380. The channel holes, or channel openings, of a sub to the possibility of the release of high quantities of heat strate can be formed in any number of shapes. For example, during filter regeneration, filter materials are required to dem the channel openings may be circular, triangular, square, hex onstrate excellent thermal attributes in terms of resistance to agonal, etc. In preferred embodiments, the channel openings both high temperatures and high temperature gradients. are triangular, Square, or hexagonal. Insufficient temperature tolerance may result in melting of the 0381. In one embodiment, the channel openings are material, while insufficient thermal shock resistance causes formed such that the thickness of the substrate material cracking. Other potential problems include microcracking between adjacent channels is substantially uniform through and spallation. In particular embodiments, the filtering Sub out the substrate. Variation in wall thickness may be from strate and catalytic Substrate of the present invention solves about 1% to about 50% in certain embodiments. one or more of these problems. 0382. In another embodiment, the channels are arranged 0374 Important considerations in designing the exact so that the walls of adjacent channels are parallel to each geometry of a wall-flow monolith is includes the following other. For example, the triangular, square, or hexagonal chan parameters: cell density, repeat distance (even distribution of nels may be formed such that the walls of adjacent channels pressure drop over the entire wall flow filter), wall thickness, are parallel to each other. open frontal area, specific filtration area, and mechanical 0383. The diameter or cross-sectional distance of the integrity factor. channels in the Substrate of the present invention can vary. In US 2008/01 12865 A1 May 15, 2008 30 certain embodiments, the channels have a diameter or cross 0390. In an exemplary embodiment, the substrate is drilled sectional distance of about 5 cm to about 100 nm. In certain with 0.04 inch diameter channels spaced every 0.06 inches embodiments, a channel has a diameter of about 100 nanom across the entire filter. These channels are Smaller than con eters. Other suitable values include a distance or diameter ventional cordierite wall flow channels. The result is vastly selected from about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, increased surface area as compared to cordierite, even with 15, 16, 17, 18, 19, and 20 mils. out taking into consideration the Surface area existing in the massive pore space of the Substrate material. The channels are 0384. A channel may vary in size along its length. For preferably “blind' channels. Exhaust emission is forced to example, the channel may be about 0.04 inch across at its pass through the channel walls, rather than flowing in and out opening but then gradually decrease in size approaching of the channels without reacting with the catalyst. either the end wall or point of the channel or the opening at the 0391) A further embodiment is directed to a catalytic or end of the channel. In one embodiment, the channel is a filtering Substrate comprising a plurality of channels having a square shape opening at the frontal Surface of sides of about pyramidal shape. The pyramidal shapes of the channels are 10 mils. The channel extends through the length of the sub such that they can be applied to any number of substrate strate and has a second opening on the rear Surface. The materials, including and in addition to the Substrates of the channel opening of the rear Surface has a square shape with present invention, such as nSiRF-C. The pyramidal channels sides of about 4 mils. The channel becomes gradually smaller can be configured such that each channel has two channel along its length from the frontal Surface to the rear Surface. openings, e.g., a flow through configuration having one on the Other similar configurations of course are contemplated. frontal surface of the substrate and one on the rear surface of 0385. The size of the channel opening may vary as well. the substrate. Alternatively, the pyramidal channels can be For example, in certain embodiments, the diameter or (cross configured such that each channel has only one opening, e.g., sectional distance) is from about 1 mil to about 100 mils. a wall flow configuration. In this embodiment, the opening of Other suitable ranges for the sized of the channel opening certain channels is situated on the frontal Surface, whereas the include, but are not necessarily limited to, about 1 to about opening of other channels is situated on the rear Surface. 500 mils, from about 1 to about 100 mils, from about 1 to Preferably, the channels are positioned so that adjacent chan about 10 mils. Other suitable sizes include a distance or nels have the opposite configuration with respect to the loca diameter selected from about 1,2,3,4,5,6,7,8,9, 10, 11, 12, tion of the channel opening. Furthermore, in certain embodi 13, 14, 15, 16, 17, 18, 19, and 20 mils. The substrate of the ments of the pyramidal wall flow configuration, the channel invention may also have channels of varying sizes. That is, terminates at an undrilled portion of the substrate. This some channels of an embodiment of a substrate has a first undrilled portion of the substrate may be either flat or pointed. plurality of channels having a first diameter or cross-sectional If the undrilled portion is flat, the longitudinal cross-sectional distance and a second plurality of channels having a second area of the channel appears trapezoidal. If the undrilled por diameter or cross-sectional distance. By way of example, a tion is pointed, the longitudinal cross area of the channel Substrate of the present invention comprises, in one embodi appears triangular. ment, one or more channels having a cross-sectional distance of about 5 mils and further comprises one or more channels Shapes and Forms having a cross-sectional distance of about 7 mils. Other varia tions of these embodiments are understood to be within the 0392 The catalytic and filtering substrates comprise a Scope of the present invention. number of suitable, and heretofore, unknown configurations. The Substrates are three-dimensional and generally have a 0386. In other embodiments, the channel diameter or front Surface (or area or face) and a rear Surface (or area or cross-sectional distance can be about 5 cm, 4 cm, 3 cm, 2 cm, face) connected by the body of the substrate to one or more or 1 cm. Substrates having channels of larger diameter or lateral Surfaces. The front and rear Surfaces can be any num cross-sectional distance are preferred for larger exhaust sys ber of shapes as described herein. The front surface refers to tems which may have exhaust pipes of one or more feet in the surface through which the fluid enters the substrate. The diameter. rear surface refers to the surface through which the fluid exits 0387. The thickness of the channel wall may vary as well. the substrate. Generally the surface is flat but may, in certain For example, the channel wall may be less than 1 mil thick. embodiments, be non-flat. Other suitable values for the channel wall thickness include 1, 0393. In certain embodiments, the substrate has the shape 2, 3, 4, 5, 6, 7, 8, 9, and 10 mils. of a cylinder. The cylinder composed of the substrate is used, 0388. The channels can be measured in terms of the num for example, to catalyze the reduction of NO in a exhaust gas. ber of channels per square inch. In certain embodiments, a 0394 Any number of suitable lengths and widths or diam substrate of the present invention has from about 50 to about eters are suitable for the substrate of the present invention. 100,000 channels per square inch. Other suitable values Suitable lengths include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, include 100, 200, 300, 400, 500, 600, 700, 800, 900, and 14, 15, 16, 17, 18, 19, and 20 inches. Of course, longer lengths 1000. Other embodiments include a catalytic or filtering sub may be preferred in diesel applications and for use in station strate having 2000 channels per square inch. ary engines, such as those used in pharmaceutical and chemi 0389. In one embodiment, the substrate of the present cal plants, manufacturing plants, powerplants, and the like. In invention comprises 600 cpsi and a wall thickness of 6 mils. another respect, the shape of the substrate can be described The cell density of a sample substrate of the present invention based on its frontal surface shape. The substrate of the present is compared with two samples of cordierite. The first and invention can be prepared such that the frontal Surface has one second cordierite samples are 100 cpsi with 17 mil wall of several physical configurations. The frontal Surface shape thickness and 200 cpsi with 12 mil wall thickness, respec can be any number of shapes, including but not limited to tively. In comparison, the Substrate of the present invention in circular, triangular, square, oval, trapezoidal, rectangular, and this embodiment has 600 cpsi with 6 mil walls. the like. Three-dimensionally, the substrates may be in the US 2008/01 12865 A1 May 15, 2008

form of a cylinder or a substantially flat disc. Commercially ner substrate of certain embodiments of the present invention, available substrates generally exist as one of these three backpressure will be minimized, and the exhaust gas will designs. Substrates can have squared corners or rounded cor move through the filter system with less effort and increased ners. Rounded corners are preferable on the frontal surface filtering capabilities. This reduction in backpressure results in shape of the substrate. Thus, in one embodiment, the substrate the engine running more efficiently meaning better gas mile of the present invention has a square shape with rounded age and more power. corners. In another embodiment, the Substrate has a rectan gular frontal shape with rounded corners. In another embodi 04.01. In one embodiment of the present invention, the ment, the Substrate has a trapezoidal frontal shape with substrate is two inches in diameter and /16th inches thick and rounded corners. has 400 times the surface area of a conventional cordierite 0395 Exemplary dimensions for a catalytic substrate filter that has a four inch diameter and is six inches long. Since according to the present invention include but are not limited the Substrate itselfhas been reduced in size, a canister can also to, those having a circular cross-sectional shape and having a be reduced in size, resulting in just a small bulge in the diameter of about 3.66, about 4.00, about 4.16, about 4.66, exhaust line. Alternatively, the substrate can be housed in the about 5.20, about 5.60, or about 6.00 inches. In other embodi exhaust manifold. ments, the catalytic Substrate has the shape of a oval cylinder 0402. In another embodiment, the substrate is in the form with cross-sectional dimensions (minor and major axis of a membrane. In this instance, the membrane comprising respectively) of about 3.15 by about 4.75 inches, about 3.54 the Substrate material as described herein having any number by about 5.16 inches, or about 4.00 by about 6.00 inches. of shapes as described above, and wherein the length of the 0396. In another embodiment, the catalytic substrate has a substrate is substantially less than the width or diameter. The shape and size that is suitable for use in a head cat. Generally, dimension can be described as a ratio of e.g., width to length, a head cat will be smaller in size than conventional catalytic or diameter to length. Suitable diameter to width ratios converters found on exhaust systems of engines. The deter include, but are not limited to, about 20:1, 19:1, 18:1, 17:1, mination of a Suitable size and shape of the head cat is within 16:1, 15:1, 14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, and the ability of one of ordinary skill in the art. The size and 5:1. shape of the head cat is configured based on the particular 0403. Furthermore, a substrate having a membrane con head and engine with which the head cat will be used. For figuration can be stacked together with one or more separate example, a conventional cordierite round Substrate that is Substrate embodiments. With a membrane configuration, a approximately 4/2 inches in diameter has a front Surface area number of catalytic or filtering substrates having a membrane of about 28.27 square inches. On a Ford 4.6 V-8, for example, configuration can be stacked together. For example, a plural there are two pre-cats having a Substrate of approximately this ity, e.g., 5, of catalytic or filtering Substrates having a cylinder dimension. These two conventional pre-cats can be replaced (or disc) shape with a diameter of about 1 inch and a length of by eight head-cats comprising a nSiRF-C Substrate compris about 0.2 inch can be stacked together to form a substrate pile ing a diameter of about 1.13 inches. 0397 Alternatively, the cylinder is used to catalyze the having a certain length, e.g., about 1 inch. oxidation of carbon monoxide and unburned hydrocarbons in 0404 In the case of a membrane configuration, in one an exhaust gas. The length of the cylinder may be greater than, embodiment, the catalytic Substrate does not contain a plu equal to, or less than the diameter of the cylinder. rality of channels running through the Substrate. Because of 0398. Different shapes and configurations of the filtering the shorter distance through which the gas must travel and Substrate and catalytic Substrate can be used based on the because, in part, of the high porosity of and low drop pressure particular application, e.g., stationary engine, on-road caused by the present invention, it is possible to form a Sub vehicle, off-road vehicle, etc. strate pile comprising a plurality of catalytic Substrates hav 0399. In another embodiment, the catalytic substrate is ing a membrane configuration. shaped to replace the commercially used substrate of a com 04.05 Furthermore a stacked membrane configuration mercially available catalytic converter. In this embodiment, also includes stacked membrane configurations in which the the substrate of the invention will have a shape and dimen individual substrates are not perpendicular to the floor of the sions that are substantially identical to substrates of available catalytic converter or particulate filter. In this embodiment, catalytic converters that use a different substrate. For the Substrate may be machined or molded so that the angle example, many catalytic converters currently used contain a between the side(s) (lateral surface) of the substrate and the substrate that is made from cordierite. The shape and size of face (front or rear surface) is about 90° or is less than or the cordierite of catalytic converters is known or can be deter greater than 90°, e.g., 80°, 70°, etc. mined by analysis. The substrate of the present invention is then prepared, either by machining or molding as described Pre-Sintering Addition of Catalyst below, such that the shape and size of the substrate of the 0406. In another embodiment, the catalytic substrate as present invention is substantially identical to that of the described herein further comprises a catalyst, wherein the known cordierite substrate. catalystis added to the Substrate material prior to the sintering process. In this case, the catalyst is generally added to the Membrane Configuration slurry before the green billet is produced. In other embodi 0400 Alternatively, the substrate has a membrane con ments, the catalyst is added to the fibers in the mixer. Alter figuration. In such a configuration, the length of the Substrate natively, the catalyst, if in the form of a liquid, is added to the is substantially less than the width or diameter of the sub slurry in certain embodiments. The substrate may be formed strate. A longer travel length for exhaust through a substrate from a slurry that comprises one or more catalysts. In one corresponds to a build up of backpressure in certain conven embodiment, the catalyst, upon sintering, adheres to the fibers tional catalytic converters and particulate filters. In the thin of the substrate. In another embodiment, the catalyst is US 2008/01 12865 A1 May 15, 2008 32 located within the pores of channel walls as opposed to be probably the biggest challenge in the washcoating process adhered mainly to the surface of the channel walls. due to the nonnewtonian character of alumina systems. 0413. The washcoat slurry can be applied to the substrates Zonation of Substrate using any known methods and procedures, including dipping 0407. In another embodiment, the catalytic substrate as or pouring over the parts, and/or in a specialized coating described herein is prepared such that different Zones in the machine. Excess slurry is cleared from channels with com substrate have different attributes. In other words, one or pressed air. The substrates can then be dried and calcined to more physical characteristics or attributes of the catalytic bond the washcoat to the monolith walls. Substrate are not uniform, or the same, throughout the entirety 0414. In certain embodiments, the washcoat can be of the substrate. For example, in certain embodiments, differ applied in one, two, or more layers. Each layer can be dried ent Zones or regions of the substrate have different densities, and calcined before the processing of next layer. There are different catalysts, different catalyst mixtures, different chan several reasons for the application of multi-layer washcoats: nel configurations, different porosities, different permeabili (1) the catalyst design may require a different chemical for ties, and/or different thermal attributes. By way of example, mulation for each layer, and (2) coating/process equipment in one embodiment, a catalytic Substrate of the present inven constraints, e.g., an inability to handle very viscous slurries tion comprises a nSiRF-C composite and a first and second which are needed to apply a thick washcoatin one-pass opera catalyst, wherein said first catalyst is applied to a first Zone of tion. said Substrate and said second catalyst is applied to a second Zone of said substrate. In a further embodiment, the substrate 0415 Typical thickness of the washcoat layer is 20-40 um has a different degrees of structural integrity through the body but values outside of the range can also be used in the present of the substrate. For example, as described herein, a densifi invention. These numbers correspond, for example, to a cation coating may be added to the Surface of the Substrate to washcoat loading of about 100 g/L on a 200 cpsi substrate, up increase hardness of its surface which would lessen possible to about 200 g/L on a 400 cpsi substrate. The specific surface damage. area of catalyst washcoat materials is in certain embodiments between 100 and 200 m/g. Ofcourse, other values are useful Washcoat in the present invention. 0416 Noble metals and other catalysts in a complex cata 0408. Another aspect of the present invention is directed to lyst system may react with each other, with washcoat com a catalytic or filtering substrate as described herein further ponents, or with the Support material and produce undesired, comprising a washcoat. In other embodiments, the catalytic catalytically inactive compounds. If such reactions occur in a Substrate further comprises a catalytic washcoat, e.g., the given catalytic system, they are difficult to prevent in the washcoat comprises a catalyst in addition to a washcoat mate conventional washcoat technology. Since the catalytic metals rial. Alternatively, in another embodiment, the washcoat are impregnated onto the finished washcoat layer, the contact material has catalytic activity. between reacting components cannot be avoided. 04.09 Suitable washcoats include silica, titania, unimpreg 0417 Segregated washcoat technologies have been devel nated Zirconia, Zirconia impregnated with a rare earth metal oped to physically separate noble metals by fixing them on a oxide, ceria, co-formed rare earth metal oxide-Zirconia, and particular base metal oxide of the washcoat before the wash combinations thereof. Other suitable washcoats are disclosed coat is applied to the Substrate. Through the use of washcoat in, e.g., U.S. Pat. Nos. 6,682,706; 6,667,012; 4,529,718: layers with different oxides and/or noble metals, the compo 4,722,920; 5,795,456; and 5,856,263, all of which are herein nents of a catalytic system can be separated. Additional ben incorporated by reference in their entirety. efit of this technology include a control of the noble metal/ 0410 Generally, a washcoat can be applied in certain base metal ratio and an improved noble metal dispersion. embodiments, from an aqueous slurry. The alumina powder Such technology can be applied to the present invention. and/or other washcoat oxides are milled to the required par Thus, in a preferred embodiment, the present invention is ticle size. The particle size distribution of the washcoat pow directed to a catalytic substrate comprising a nSiRF-C, at der affects the mechanical strength of the finished washcoat least two catalytic metals, and a washcoat, wherein said two and its adhesion to the Substrate, as well as the rheological catalytic metals are physically separated. attributes of the slurry during the washcoating process. Alu 0418 Segregated Washcoat Schematic: Segregated wash mina, a very hard material, is, in certain embodiments, milled coats were first applied for automotive 3-way catalysts. An using air-jet or ball mills. example of Such a catalyst is a tri-metal system which 0411. In the next step, the materials are dispersed in acidi includes platinum, palladium and rhodium. The first layer of fied water in a tank with a high-shear mixer. The solid content the catalyst is composed of Pd/Al2O. The second (surface) in the slurry is typically 30-50%. After prolonged mixing, the layer is composed of Rh/Pt/Ce—Zr. That design prevents the alumina Suspension becomes a stable colloidal system. formation of palladium-rhodium alloys which otherwise 0412. The amount of washcoat deposited on the substrates could cause catalyst deactivation. depends on, and can be controlled by, the rheological 0419 Aluminum oxide oralumina is the basic material for attributes (viscosity) of the slurry. The aluminum oxide emission control catalyst washcoat. The high Surface area slurry, in certain instances, is a nonnewtonian fluid which gamma crystalline structure (Y-Al2O) is used for catalyst changes its viscosity with time and with the amount of applications. It is characterized by high purity. Presence of mechanical energy Supplied to the system (shear rate). At any certain elements in the Al2O can influence its thermal stabil steady sheer rate, the viscosity of the slurry is a function of its ity, both negative and positive. Small amounts of NaO pH. In certain embodiments, the viscosity can be controlled present in Al-O act as a flux, enhancing the sintering of by pH adjustment. Precise viscosity control, however, is alumina. In contrast, several metal oxides, including La-Os. US 2008/01 12865 A1 May 15, 2008

SiO, BaO, and CeO have a stabilizing effect on alumina Z). This is then treated with a salt solution containing a Surface area and reduce its sintering rate. Stabilized aluminas catalytic cation forming the metal exchanged Zeolite (MZ). are commercially available. 0428 Zeolites, due to their repeatable and well defined 0420. In other embodiments, cerium dioxide, or ceria, is a pore structure, are excellent adsorption materials. They have component of the catalyst washcoat, added, for example, in been used as adsorbents in numerous applications including quantities of up to 25%. In other embodiments, ceria is add in drying, purification and separation. Synthetic Zeolites are also quantities of about 5%, 10%, 15%, 20%, and 25%. Ceria is an used as catalysts in petrochemical processing. important promoter in the automotive emission control cata 0429. In recent years, Zeolites have been increasingly used lyst. One function of ceria in the three-way catalyst is oxygen for diesel emission control, both as catalysts (SCR, lean NOx storage, which is possible through a cycling between Ce" catalyst) and adsorbers (hydrocarbon traps in diesel oxidation and Ce". Other effects attributed to ceria include stabiliza catalysts). tion of alumina, promotion of the steam reforming reaction, 0430. It is understood that further embodiments of the promotion of noble metal dispersion, and promotion of noble invention include any of the specific Substrate embodiments metal reduction. described herein, further comprising any of the specific wash 0421 Certain diesel oxidation catalyst formulations coat embodiments. include high loadings of ceria. The function of ceria is cata lytic oxidation/cracking of the soluble organic fractions of Oxygen-Storing Oxide diesel particulates. 0422 High surface area cerium oxide can be produced, for 0431. In another embodiment, the catalytic substrate or example, by calcination of cerium compounds. The BET filtering substrate of the present invention further comprises surface area of ceria can be as high as 270 m/g. In other an oxygen-storing oxide. The oxygen-storing oxide, for embodiments, for example in a three-way catalyst, ceria of example CeO, has an oxygen storing capacity (hereafter about 150 m/g surface area is used. High temperature stabi abbreviated as “OSC), that is, the capacity to occlude gas lized varieties, which are capable of withstanding 900-1000 eous oxygen and to release the occluded oxygen. More spe C., have surface areas of about 6-60 m/g and are suitable for cifically, CeO2 is added for adjusting the oxygen concentra use in the present invention. tion of gaseous atmosphere, so that excess oxygen in the 0423. A catalytic substrate or filtering substrate of the gaseous atmosphere is occluded into the crystalline structure of CeO2 in an oxygen-rich state (i.e., fuel-lean state which invention in other embodiments further comprises Zirconium may be simply referred to as “lean state’) for assisting the oxide. In certain embodiments, the Zirconium oxide increases catalytic converter in reducing NOx to N, while releasing the the thermal stability of the substrate. occluded oxygen into the gaseous atmosphere in a CO- and/or 0424 Titanium dioxide is used with some diesel catalysts HC-rich state (i.e., fuel-rich state which may be simply as an inert, non-sulfating carrier. Two important crystal struc referred to as "rich state') for assisting the catalytic converter tures of titanium dioxide include anatase and rutile. The ana in oxidizing CO and HC to CO, and HO. Thus, the catalytic tase form is important for catalyst applications. It has the activity of the catalytic substrate is enhanced by the addition highest surface area of 50-120m/g and is thermally stable up of CeO. Other oxygen-storing oxides include PrO and the to 500°C. The rutile structure has a low surface area of below like, as disclosed in U.S. Pat. No. 6,576,200. Further embodi 10 m/g. A conversion of anatase into rutile, which takes place ments include any specific Substrate embodiment described at about 550° C., leads to catalyst deactivation. In another herein, further comprising an oxygen-storing oxide, e.g., embodiment of the present invention, the catalytic substrate comprises a nSiRF-C, preferably an AETB or OCTB, a cata CeO. lyst, and titanium oxide. SOX Oxidation 0425 Zirconium oxide can be used as a thermal stabilizer and promoter of ceria in the automotive three-way catalyst 0432. In the presence of certain metal catalysts, especially and also as a non-sulfating component of diesel oxidation platinum, sulfur present in the fuel, for example in diesel fuel, catalyst washcoats. Zirconium oxide has a BET Surface area is converted to SOX which can then create environmentally of 100-150 m/g. It rapidly looses its surface area at 500-700° harmful Sulfuric compounds, such as Sulfuric acid fumes, in C. Better thermal stability can be achieved by the use of a the exhaust. Most sulfates are typically formed over platinum wide range of dopants including La, Si, Ce, and Y. catalysts at relatively high exhaust temperatures of about 0426 Zeolites are synthetic or naturally occurring alu 350-450° C. While there is a dire need to remove Sulfur from mina-Silicate compounds with well defined crystalline struc the gasoline and diesel fuel formulations, in the interim, cata tures and pore sizes. The dimensions of Zeolite pores are lyst formulations have tried to reduce that problem to their typically between 3 and 8 A, which falls into the range of best possible extent. molecular sizes. Any molecule of a larger cross-sectional area 0433. An exemplary platinum catalyst developed by is prevented from entering the channel of the Zeolite cage. For Engelhard is composed of 5-150 g/ft Pt/Rh at 5:1 ratio and this reason, Zeolites are often referred to as molecular sieves. 30-1500 g/ft of MgO (U.S. Pat. No. 5,100,632 (Engelhard Zeolites are characterized by high specific surface areas. For Corporation)). The catalyst can be impregnated onto Sub example, the ZSM-5 Zeolite has surface area of about 400 strates from water based solutions. A filter coated with the m?g. Zeolite mordenite has a surface area of about 400-500 catalyst preferably is used for exhaust temperatures of 375 m?g. Most zeolites are thermally stable up to 500° C. 400° C. to regenerate. The function of rhodium in the above 0427 Zeolites for some catalytic applications are ion formulation is to suppress the catalytic oxidation of SO and, exchanged with metal cations. The acid form of Zeolite (HZ) thus, the Sulfate mask in the catalyst. is first treated with an aqueous solution containing NH" 0434. A catalytic substrate of the present invention may, in (NHNO) to form the ammonium exchanged zeolite (NH" certain embodiments, provide Solutions to these problems by, US 2008/01 12865 A1 May 15, 2008 34 for example, having an improved thermal profile and thereby Examples of suitable protective coatings are disclosed in U.S. reducing thermal breakdown of the catalyst. Pat. Nos. 5,702,761 and 5,928,775, and 5,079,082, the dis 0435 Catalyst poisoning is a significant source of catalyst closures of which are incorporated herein by reference. Thus, deactivation. It can occur when Substances which are present in a preferred embodiment, the invention provides a substrate in exhaust gases chemically deactivate the catalytic sites or having, among other attributes, a higher porosity, a higher cause fouling of the catalytic Surface. Poisons in exhaust permeability, and a Sufficient hardness compared to conven gases from internal combustion engines may be derived from tional Substrates. Said coating can be used with one or more of lube oil components or from the fuels. the specific filtering and catalytic substrates described herein. 0436 Interactions between different catalyst species or between catalyst species and carrier components are another Pressure Drop temperature-induced mode of catalyst deactivation. An example is the reaction between rhodium and CeO2 in an 0442. The present invention also provides a substrate that automotive three-way catalyst. This type of problem can be provides for an improved pressure drop for catalytic convert reduced by using alternative carriers and special washcoat ers and particulate filters. Thus, in certain embodiments, a technologies which physically separate the reacting compo Substrate of the present invention permits one to provide a nents and are known in the art. means for removing and/or filtering an exhaust gas without a 0437. A further advantage of the present invention is that a substantial buildup of back pressure, or alternatively with a nSiRF-C can be pumped with different Zones to separate lower buildup of back pressure compared to conventional physically incompatible components, or alternatively can be catalytic and particulate filters. 0443) The flow of exhaust gas through a conventional cata utilized as a stacked membrane configuration with incompat lytic converter creates a Substantial amount of backpressure. ible components in separate membrane Substrates. The backpressure buildup in a catalytic converter is an impor 0438 Catalyst deactivation may also occur due to a physi tant attribute to catalytic converter success. If the catalytic cal washcoat loss through erosion and attrition. That mecha converter is partially or wholly clogged, it will create a nism may also be important for emission control catalyst restriction in the exhaust system. The subsequent buildup of because of the high gas Velocities, temperature changes, and backpressure will cause a drastic drop in engine performance differences in thermal expansion between the washcoat and (e.g., horsepower and torque) and fuel economy, and may Substrate materials. even cause the engine to stall after it starts if the blockage is Catalyst Cover severe. Conventional attempts to reduce pollutant emissions are very expensive, due to both the cost of materials and 0439. In certain applications, adsorber catalysts are used retrofitting or manufacturing an original engine with the to convert NOx into salts which can then be manually appropriate filter. removed in a regenerative process. However, the presence of 0444. A substrate of the present invention has, in certain sulfur in the fuel can lead to the formation of insoluble SO embodiments, the attribute of producing a lower or smaller salts, such as barium sulfate, which can form a protective pressure drop than conventional Substrates used in catalytic coating on top of the catalysts and reduce their efficiency. An converters or particulate filters. The present invention in some advantage of certain embodiments of the present invention is embodiments provides a lower buildup of soot in the particu that the catalytic substrate is less susceptible to reduced effi late filter and in Some instances allows less frequent need for ciency due to the coating from Sulfate salts. replacement of the filter compared to conventional particulate 0440. In another embodiment, the catalytic substrate or filters. filtering substrate of the present invention further comprises a protective coating Suitable for ceramics. For example, such a SPECIFIC EMBODIMENTS suitable protective coating is disclosed in U.S. Pat. No. 5.296, 288, which is incorporated herein by reference in its entirety. 0445. The present invention is also directed to specific This coating is also known as Protective Coating for Ceramic embodiments of the catalytic and filtering substrates Materials (PCC). Another suitable, and related coating, is described above. Specific embodiments include a substrate available as EmisshieldTM coating (Wessex Incorporated, comprising, or alternatively consisting of or consisting essen Blacksburg, Va.). The emissivity agents in EmisshieldTM tially of a nSiRF-C and a catalyst. An additional embodiment enhance the emissivity of materials, especially at high tem is a filtering substrate comprising anSiRF-C and a plurality of peratures. Additionally, a protective coating may lessen dam channels. age from external impact and wear forces. Suitable coatings 0446 For example, certain embodiments of the substrate are disclosed in U.S. Pat. Nos. 5,702,761 and 5,928,775, have a plurality of the attributes described above. In other issued to DiChiara, Jr. et al. and U.S. Pat. No. 5,079,082, embodiments, the substrate of the invention has 2, 3, 4, 5, 6, issued to Leiser, et al., the disclosures of which are incorpo 7, 8, 9, or 10 of the attributes described above. The specific rated herein by reference. Said coating can be used with one embodiments can comprise any combination of attributes. or more of the specific filtering and catalytic Substrates The catalytic substrate is further illustrated by the following described herein. nonlimiting specific embodiments. 0441. In certain embodiments, the catalytic substrate or 0447. In one embodiment, the substrate of the invention filtering Substrate is resistant to damage from thermal shock comprises a nSiRF-C composite having a porosity of about and thermal cycling. However, certain Substrates are rela 96% to about 99%; a density of about 10 to about 14 lb/ft; a tively soft and can be damaged by external impact and wear plurality of channels having a wall-flow configuration; and forces. To lessen Such damage, in a preferred embodiment, optionally a catalyst. the catalytic or filtering substrate of the present invention 0448. In one embodiment, the substrate of the invention further comprises one or more protective coatings to the Sur comprises a nSiRF-C composite comprising aluminaboria face, preferably the exterior surface, of the substrate. silica fibers, silica fibers, and alumina fibers having a porosity US 2008/01 12865 A1 May 15, 2008

of about 96% to about 99%; a density of about 10 to about 16 0452. Another suitable catalytic substrate of the present invention is a nSiRF-C as described herein; and a catalyst 1b/ft, preferably about 10, 11, 12, 13, 14, 15, or 16 lb/ft; a comprising: a carrier pre-doped with copper oxide (CuO); at plurality of channels having a wall-flow configuration; and least one precious metal as a main catalyst selected from the optionally a catalyst. In other embodiments, the Substrate group consisting of platinum (Pt), palladium (Pd), rhodium further comprises a washcoat, preferably of aluminaoxide or (Rh) and rhenium (Re), wherein the at least one precious a derivated thereof. metal is doped on the Surface of the pre-doped carrier, and at 0449 In another embodiment, the substrate of the inven least one metal oxide as a co-catalyst selected from the group consisting of antimony trioxide (SbO), bismuth trioxide tion comprises a Substrate having one or more of the follow (BiO), tin dioxide (SnO), and mixtures thereof, wherein ing attributes: tensile strength of from about 100 to about 150, the at least one metal oxide is doped on the surface of the preferably about 130 to about 140, more preferably about 133 pre-doped carrier. Such a catalyst is described in U.S. Pat. No. psi; thermal conductivity of about 0.5 to about 0.9, preferably 6,685,899, which is incorporated by reference in its entirety. about 0.7 to about 0.8, more preferably about 0.770 BTU-ft*/ 0453. In one embodiment, the substrate is suitable for hr ft. F.; a thermal coefficient of expansion of about 1 to being used in a catalytic converter that is placed inside the engine head before the exhaust manifold in relation to the about 5x10, from about 1 to about 3x10, more preferably flow of exhaust gas. about 1.95x10 (tested from 77° F-1000 F); an average 0454. Additional embodiments of the catalytic substrate density of from about 15.5 to about 17, preferably about 16 to include a catalytic Substrate comprising an nSiRF-C compos about 16.8, more preferably about 16.30/lb/ft; and option ite having the approximate attributes shown in the following ally a catalyst. table.

Embodiment 1 Embodiment 2 Embodiment 3 Thermal 4-100 x 102 W/m-K 5-7 x 102 W/m-K 6.04 F-02 Wim-K Conductivity Specific Heat 10-150 Jomo K 600-700 x 10 J/kg-K 640 x 10 J/kg-K Density .05-5gmfcc 0.1-0.3 gmfcc 0.2465 gmfcc Emissivity 68-97 O.7-0.92 O.88 Axial Strength 1.5 to 3.5 MPa. 2-3 MPa. 2.21 MPa. Noise Attenuation 40-100 db 70-80 db 74 db at 3500 rpm Porosity 80-99% 97-98% 97.26% Permeability At least 600 900-occ 1093-occ Regeneration Time O.5 to 15 Sec O.6-0.9 O.75 Sec Surface Area 70,000-95,000 in? 88,622 in Melting Point 17OO-SOOO 3OOO-4OOO C. 3,000° C. Thermal Expansion 0.001 x 10 to 9 x 10 0.1 x 107 to 0.4 x 107 0.25 x 1071/C. (CTE)

0450. In another embodiment, the substrate of the inven 0455 Another specific embodiment is directed to a cata tion comprises a Substrate having one or more of the follow lytic substrate comprising an nSiRF-C as described in Table ing attributes: tensile strength of about 50 to about 70, pref 1; and a catalyst selected from the group consisting of palla erably about 60 to about 65, more preferably about 63 psi; dium, platinum, rhodium, derivatives thereof, and combina thermal conductivity of about 0.5 to about 0.9, preferably tions thereof. about 0.7 to about 0.8, more preferably about 0.770 BTU-ft*/ 0456. A preferred substrate comprising high-grade non hr ft F.; a thermal coefficient of expansion of about 1 to woven refractory fibers is 90% to 98% porous and has an about 5x10, from about 1 to about 3x10, more preferably emissivity value between 0.8 and 1.0. about 1.77x10 (tested from 77° F-1000 F); an average 0457. In one embodiment, the filtering substrate of the density of from about 7 to about 9, preferably about 8.2 to present invention comprises or consists essentially of a about 8.6, more preferably about 8.40/lb/ft; and optionally a nSiRF-C and further includes a frontal inlet end and an outlet catalyst. end, a matrix of thin, porous, intersecting vertically extending 0451. In another embodiment, the substrate of the inven walls and horizontally extending walls, which define a plu tion comprises a Substrate having one or more of the follow rality of channels extending in a Substantially longitudinal ing attributes: tensile strength of about 60 to about 80, pref and mutually parallel fashion between the frontal inlet end erably about 70 to about 79, more preferably about 74 psi; and the outlet end; the frontal inlet end includes a first section thermal conductivity of about 0.5 to about 0.9, preferably of cells plugged along a portion of their lengths in a non about 0.7 to about 0.8, more preferably about 0.765 BTU-ft*/ checkered pattern and a second section of cells plugged in hr ft F.; a thermal coefficient of expansion of about 1 to checkered pattern, the first section of non-checkered plugged about 5x10, from about 1 to about 3x10, more preferably cells being Smaller than the second section of checkered about 1.84x10 (tested from 77° F-1000 F); an average plugged cells. Such a configuration is further described in density of from about 9 to about 11, preferably about 9.5 to U.S. Pat. No. 6,673,414, which is herein incorporated by about 10.5, more preferably about 10 lb/ft; and optionally a reference in its entirety. Up to three-fourth of the cells of the catalyst. first section may be unplugged. Alternatively, up to one-half US 2008/01 12865 A1 May 15, 2008 36 of the cells of the first section may be unplugged. Alterna extremely high temperatures, i.e., above 500 degrees Celsius, tively, up to one-fourth of the cells of the first section may be Such as near the combustion chamber; (2) is more resistant to unplugged. vibration degradation; and (3) still maintains or improves 0458 It is further understood that the invention is directed particulate matter burning effect. The ability to achieve par to embodiments consisting of or consisting essentially of the ticulate matter burning even without a catalyst would also limitations of the various embodiments. Thus, for example, provide significant savings on catalyst and coating costs. having described one embodiment as a catalytic Substrate 0467. Once a filter captures particulate matter (e.g., soot), comprising a nSiRF-C and a catalyst, it is understood that the the particulate matter needs to be completely combusted by invention further encompasses a catalytic Substrate consist raising its temperature Sufficiently in the presence of oxygen. ing of or consisting essentially of a nSiRF-C and a catalyst. Combustion of the particulate matter can be accomplished by utilizing the existing temperature of the exiting exhaust and/ Methods of Catalyzing a Reaction and Filtering or providing an auxiliary Source of heat. The time it takes to 0459. Another aspect of the invention is directed to a burn the particulate matter at this temperature is referred to as method of catalyzing a reaction comprising providing a cata the required “residence time.” “regeneration time,” or “burn lytic substrate of the present invention; and directing a flow of off period. A shorter residence time of particulates in the a fluid over and/or through the catalytic substrate at a tem Substrate pores translates into a reduced occurrence of pore perature sufficient to catalyze said reaction. Preferably, the clogging build up, which buildup can cause increased gas reaction converts pollutants to non-pollutants. For example, flow backpressure requiring excessive energy to operate effi the catalytic Substrate in one embodiment converts carbon ciently. Lower residence time is, therefore, preferred. monoxide to carbon dioxide. 0468. One conventional DPT is exemplified in U.S. Pat. 0460. The method of catalyzing is performed using a sub No. 5,611,832 (Isuzu Ceramics Research Institute Co., Ltd.), strate comprising alumina enhanced thermal barrier as which discloses a DPT for collecting particulates from described herein. A number of substrates exhaust gas discharged from a diesel engine. The DPT filter is 0461. In a preferred embodiment, the substrate contains a constituted of a woven inorganic fiber covered with a silicon Suitable catalysis. carbide ceramic, and metallic wire nets disposed there 0462. In one embodiment, the present invention is directed between. to a method of filtering an exhaust gas comprising providing 0469 Additional uses of a filtering substrate or catalytic a filtering or catalytic Substrate of the present invention as substrate includes ability to clean or filter from a fluid flow described above, and directing a flow of a fluid, e.g., a gas or such pollutants and impurities as: dust/soot, smoke, pollen, liquid, through the Substrate, wherein said gas contains par fluids, bacteria/viruses, odor, oil, Volatile organic com ticulate matter. pounds, liquids, methane, ethylene, and a wide variety of 0463. In another embodiment, the method further com other chemicals, including those chemicals listed as the EPA's prises burning off of the filtered particulate matter. The burn 188 “toxic air pollutants.” ing off of the filtered particulate matter converts the accumu 0470 A method of catalyzing a reaction and/or filtering a lated particulate matter mainly into nonpollutant matter, Such fluid may be useful in any number of industries or applica as, for example, gaseous compounds. tions, in particular one or more of the following: Aerospace 0464. This aspect of the present invention is of particular Industry; Asbestos; Asphalt Roofing and Processing: Auto use with diesel engines. In another aspect, the invention is and Light Duty Truck (surface coating); Benzene Waste directed to a method of filtering wherein the filtering utilizes Operations; Boat Manufacturing; Brick and Structural appli a diesel particulate filter. cations; Clay Products Manufacturing; Cellulose Products 0465 Diesel engines (where compression alone ignites Manufacturing; Caroxymethylcellulose Production; Cellu the fuel) have recently come under worldwide scrutiny for lose Ethers Production: Cellulose Food Casing Manufactur their exhaust emissions, which contain a large number of ing: Cellophane Production; Chromium Electroplating; Coke harmful particulates in addition to toxic gases. Manufactur Oven: Pushing, Quenching & Battery Stacks; Coke Ovens; ers response has been to apply known catalytic converter Combustion Turbines; Degreasing Organic Cleaners; Dry technology to diesel engines. Unfortunately, regulations Cleaning; Engine Test Cells/Stands; Fabric Printing, Coating regarding emission standards have exceeded the physical and & Dyeing; Ferroalloys Production; Flexible Polyurethane economic limitations of conventional catalytic converters. Foam; Fabrication Operation; Flexible Polyurethane Foam Diesel emissions differ from gasoline emissions in that a Production; Friction Products Manufacturing; Gasoline Dis greater amount of particulate matter is generated. For this tribution (Stage 1); General Provisions; Generic MACT; Haz reason, existing technology for exhaust emission capture, ardous Waste Combustion; Hazardous Organic NESHAP: combustion, and oxidation will not comply sufficiently with Hydrochloric Acid Production; Industrial, Commercial and the most stringent emission standards. Institutional Boilers; Industrial Cooling Towers Process 0466. A majority of buses are manufactured with or are Heaters; Integrated Iron & Steel; Iron Foundries (surface retrofitted with 85% efficient diesel particulate traps coating); Leather Finishing Ops.; Lime Manufacturing; Mag “DPTs'). DPTs have a high cost, are highly complex, lower netic Tape: Manufacturing Nutritional Yeast; Marine Vessel fuel economy, and have low durability. Further regulations Loading Operations; Mercury Cell Chlor-Alkali Plants: require 100 percent compliance by 2010 and DPTs alone Metal Coil (Surface coating); Metal Can (Surface coating); cannot satisfy these regulatory requirements. The high tem Metal Furniture (Surface Coating); Mineral Wool Products: perature of an engine or exhaust gas permits the particulate Misc. Coating Manufacturing; Misc. Metal Parts and Prod matter to combust with a shorter residence time. Moving the ucts; Municipal SolidWaste Landfills: Natural Gas Transmis filter closer to the combustion chamber of the engine or add sion and Storage; Off-Site Waste Recovery Operations: Oil & ing an auxiliary heat source can provide increased heat. Natural Gas Production; Organic Liquids Distribution (non Therefore, what is needed is a filter that (1) can be placed in gasoline); Paper & Other Web (Surface Coating); Pesticide US 2008/01 12865 A1 May 15, 2008 37

Active Ingredient Production; Petroleum Refineries; Pharma viruses, odor, VOC, other chemicals (gaseous, Solid, or liq ceuticals Production: Phosphoric Acid/Phosphate Fertilizer; uid); General VOC applications for processing/manufactur Plastic Parts (Surface Coating); Polymers and Resins; Poly ing (wood products, coating industry, textile industry, etc); ether Polyols Products; Polybutadiene Rubber; Polysulfide Glass/ceramics; Greenhouses; Home appliances—cold (Re Rubber; Phenolic Resins; Polyethylene Terephthalate: Poly chargeable appliances) (odor, oil, VOC, other chemicals (gas vinyl Chloride and Copolymers Production; Portland Cement eous, Solid, or liquid)); Home appliances—hot (Water Heat Manufacturing; Primary Aluminum Production; Primary ers & Domestic Heaters Appliances) (odor, oil, VOC, other Lead Smelting; Primary Copper; Primary Magnesium Refin chemicals (gaseous, Solid, or liquid)); HVAC Sanitation); ing; Printing/Publishing; Publicly Owned Treatment Works Hydrogen Reformation (VOC, methane, other chemicals (POTW); Pulp & Paper (non-combust) MACT I; Pulp & (gaseous, solid, or liquid)); Medical Growth Medium; Office Paper (non-chem) MACT III; Pulp and Paper (combustion buildings; Oil/petrol transport; Other Electro-Magnetic Insu sources) MACT II; Pulp & Paper Mills; Reciprocating Int. lation (Electro-Magnetic Shield); Paint usage; Petrol stations Combust. Engine; Refractory Products Manufacturing; Rein (odor, VOC); Polymer processing (odor, VOC, other chemi forced Plastic Composites Production; Secondary Alu cals (gaseous, Solid, or liquid); Recovery of precious metals/ minium; Secondary Lead Smelters; Semiconductor Manu catalysts from hot gases and liquids; Restaurant Fumes; Sew facturing; Shipbuilding & Ship Repair; Site Remediation; age and bio-waste (bacteria/viruses, odor, VOC, methane, Solvent Extraction for Vegetable Oil Production: Steel Pick other chemicals (gaseous, Solid, or liquid)); Slaughterhouses; ling-HCL Process; Taconite Iron Ore Processing: Tetrahy Smoke Houses (dust/soot, smoke); Sound Insulation; Swim drobenzaldehyde Manufacturing; Tire Manufacturing; Wet ming pools; Tanning studios; Tunnels and car parks (dust/ Formed Fiberglass: Mat Production; Wood Building Prod Soot, odor, VOC, methane, other chemicals (gaseous, Solid, or ucts; Wood Furniture; and Wool Fiberglass Manufacturing. liquid)); and Waste Incineration (dust/soot, odor, VOC, other Such industries and applications often utilize EPA-regulated chemicals (gaseous, Solid, or liquid)). stationary sources of emissions. 0471. Other suitable uses include a filtering or catalytic Process of Preparing a Catalytic or Filtering Substrate process in one or more of the following applications: Cars 0473. In another aspect, the present invention is directed to (dust/soot, odor, oil filtration, VOC, methane, other chemicals a process of preparing any one of the Substrates (catalytic or (gaseous, Solid, or liquid)); Water Jets (dust/soot, odor, oil filtering) as described herein. The present invention is also filtration, VOC, methane, other chemicals (gaseous, Solid, or directed to a process of preparing a catalytic Substrate of the liquid)); Snowmobiles (dust/soot, odor, oil filtration, VOC, present invention. In another aspect, the present invention is methane, other chemicals (gaseous, Solid, or liquid)); Small directed to process of preparing a diesel particulate filter. A engine (dust/soot, odor, oil filtration, VOC, methane, other number of methods as described below can be used to prepare chemicals (gaseous, Solid, or liquid)); Motorcycles (dust/ the substrate. Soot, odor, oil filtration, VOC, methane, other chemicals (gas 0474. In one aspect of the present invention, a catalytic eous, solid, or liquid)); Mobile Diesel Engines (dust/soot, Substrate as described herein can be prepared using a com odor, VOC, methane, other chemicals (gaseous, Solid, or liq mercially available billet of nSiRF-C. The commercially uid)); Stationary Diesel Engines (dust/soot, odor, VOC, meth available billet of nSiRF-C is machined into a suitable shape, ane, other chemicals (gaseous, Solid, or liquid)); Power Sta form, and size. A substrate of the invention can be prepared by tions (dust/soot, odor, VOC, methane, other chemicals as large brick of suitable Substrate material by machining the (gaseous, solid, or liquid)); Refineries (VOC, other chemicals brick into a shape suitable for use in the present invention. The (gaseous, Solid, or liquid)); and Chemical and Pharmaceutical crude block can be easily cut or sawed into a preformed shape, Manufacturing (dust/soot, bacteria/virus, odor, oil filtration, and then sanded, turned or machined into the final desired VOC, methane, other chemicals (gaseous, Solid, or liquid). shaped “slug.” Although the composition of the substrate 0472. Furthermore, additional catalytic and/or filtering material is very resilient to chemical, heat, thermal, and vibra applications include the use of a Substrate according to the tional shock, the hardness is the substrate material is low. This present invention in one or more of the following areas: low hardness permits machining with little or minimal Agricultural & Forestry Incineration Emissions; Bakeries amount of resistance or wear on tools. Despite the fact that the (dust/soot, Smoke, odor, VOC, other chemicals (gaseous, block has a low hardness and is soft, it is very durable and easy solid, or liquid)); Bio-Medical Fluid Filtration; Breweries and to machine, Sculpt, or shape. For example, in certain embodi wineries (odor); Cabin air (car, Submarine, space industry, ments, a Substrate material is, on a Moh's hardness scale, airplane) (dust/soot, Smoke, pollen, bacteria/viruses, odor, usually between 0.5 and 1.0 (or 1-22 on the Knoop hardness VOC, other chemicals (gaseous, Solid, or liquid)); Clean scale) with talc being the softest at 1 (1-22 Knoop hardness) room applications (dust/soot, Smoke, pollen, bacteria/vi and diamond being the hardest at 10 (8,000-8,500 Knoop ruses, odor, oil, VOC, methane, other chemicals)); Commer hardness). Other suitable values Certain prior art substrate cial Incineration Emissions (odor, VOC, other chemicals materials are harder. For example, silicon carbide has a Moh’s (gaseous, Solid, or liquid)); Commercial Toxic Organic Emis hardness of 9-10 (2,000-2950 Knoop hardness). sions; Dry cleaners (VOC, other chemicals (gaseous, Solid, or 0475 With reduced effort compared to certain conven liquid)); Evaporative Emissions (such as Fuel Evaporation tional substrates such as cordierite, the billet is shaped, Management); Fireplaces); Flame grilling (fast food) (dust/ Sanded, turned, or machined, providing unlimited shaping Soot, Smoke, odor, VOC, other chemicals (gaseous, Solid, or capabilities of slug formation. The machining can range from liquid); Fitness Centers); Fluid Filtration in General (Drink turning a cylinder on a lathe, sawing to shape with a keyhole ing water treatment)); Food processing and storage (odor, saw, band saw or jigsaw, Sanding the shape or Smoothing the other chemicals (gaseous, Solid, or liquid); Foundries (odor); Surface, or any other method of machining commonly used on Fuel Cells (VOC, methane, other chemicals (gaseous, solid, other solid materials and known in the art. The billet can be or liquid); Gas Masks (dust/soot, Smoke, pollen, bacteria/ machined down to very exacting tolerances with the same US 2008/01 12865 A1 May 15, 2008 accuracy as machining metals, woods, or plastics. If the billet 0492 heating, preferably prewarming and incrementally is cast in cylindrical molds with the desired diameter of the heating, the green billet in an oven at approximately 2000 final shape, the machining would simply require cutting and 25000 F. sanding the cylindrical billet to the desired thickness. This 0493 As stated above, the billet is then optionally process also reduces Substrate loss due to excessive machin machined to form a Substrate of the present invention. ing, and speeds up the preforming process as well. 0494. In another embodiment, the process further com 0476. In certain embodiments, the frontal shape of the prises machining a plurality of channels in the Substrate. substrate is circular 510, oval 520, and racetrack 530, as 0495. In another embodiment, the process further com shown in FIG. 5. As is readily understood, the shapes do not prises adding a washcoat to the Substrate. have to be exact. Three-dimensionally, the substrates may be 0496. In another embodiment, the process further com in the form of a cylinder or a substantially flat disc. Designs prises adding a catalytic coating to the Substrate. with Squared corners, in certain applications, are not as effec 0497. In a further embodiment, the mixing of the fibers is tive. Although easy to machine, square or angular designs performed after the washing and heating of the fibers. have proven to be a trap for rust and corrosives, e.g., road salt. 0498. In further embodiment, boron nitride is used in the Therefore, rounded corners are preferable on the frontal sur process of making a Substrate of the present invention. face shape of the slug in certain embodiments. BN=>B+N 0477 The billet may be shaped by a band saw, jigsaw, 0499. In yet an additional embodiment, a thickening agent CNC, or other method known to one of ordinary skill in the is used. Preferably, the thickening agent and dispersant used art. The billet may be further shaped by a hand rub, lathe in the process are substantially removed from the substrate Sanding, belt Sanding, or orbital sanding. Airborne particles during a heating step. For example, the thickening agent and are preferably vacuumed to prevent them from clogging the dispersant may be combusted during the sintering process. pores of the material. Further, these particles can enter the 0500. The substrate 2510 is derived from a billet created bearings of the drill press and destroy it, grinding away and by forming a rigid configuration of chopped and/or non scoring the bearings. The ceramic dust is also very fine and woven inorganic fiber and a binding agent. The billet is can be easily inhaled by operator. machined or worked into the desired external dimensions for 0478. In another embodiment, the present invention is the Substrate 2510. The interior of the Substrate 2510 is then directed to a method of preparing a catalytic or filtering Sub machined or worked to provide the desired surface area strate according to the present invention comprising prepar enhancement configuration, e.g., channels, washcoat, or cata ing a billet of a nSiRF-C composite; and optionally machin lyst. A durable inorganic hardened coating 2511 may be ing said billet to form a substrate of the present invention. If applied to the Substrate 2510 by brushing, spraying, dipping, the billet is prepared in a shape suitable for use in one or more or any other common application method. In addition, the processes of the present invention, the billet does not neces substrate 2510 may include an oxidation or reduction catalyst sarily need to be machined to a different shape. In this applied by brushing, spraying, dipping, or any other common instance, the billet is prepared with a mold, as described application method. below, having a suitable shape. Alternatively, the billet or 0501. In one embodiment, the catalytic or filtering sub Substrate may be machined to a suitable shape. Further, as strate of the present invention comprises a nSiRF-C; and a described in more detail below, a plurality of channels are coating comprising, in admixture, silicon dioxide powder in machined into the Substrate. an amount of from 23.0 to 44.0 wt %; colloidal silicon dioxide 0479. The step of preparing the billet (or substrate) com in an amount from 25.0 to 45.0 wt %, water in an amount from prises known methods of preparing these materials. Any 19.0 to 39.0 wt %; and one or more emittance agents selected known method of preparing a suitable billet or Substrate can from the group consisting of silicon tetraboride, silicon be used. For example, suitable processes are disclosed in U.S. hexaboride, silicon carbide, molybdenum disilicide, tungsten Pat. Nos. 4,148,962 and 6,613.255, each of which is incorpo disilicide and Zirconium diboride; wherein said coating has a rated by reference herein in its entirety. solids content of from 45 to 55 wt %. Such a coating is 0480. By way of a non-limiting example, in one embodi disclosed in U.S. Pat. No. 5,296,288. ment, the steps of preparing a suitable Substrate comprise: 0502. The present invention utilizes a plurality of high 0481 heating a plurality of refractory silica fibers, refrac grade non-woven sintered inorganic refractory fibers, such as those present in AETB. Other suitable materials for use as a tory alumina fibers, and refractory aluminoborosilicate nSiRF-C in the present invention include: AETB-12 (having fibers: a composition of about 20%. Al-O, about 12% (14% BO, 0482 mixing said fibers; 72% Al-O, 14% SiO; NEXTELTM fiber), and about 68% 0483 washing said fibers: SiO): AETB-8 (having a composition of about 20% Al-O. 0484 optionally chopping said fibers to one or more about 12% (14% BO, 72% Al-O, 14% SiO, NEXTELTM lengths; fiber), 68% SiO2); FRCI-12 (having a composition of about 0485 blending or mixing the chopped fibers into a slurry; 78% wt. silica (SiO), and 22% wt. aluminoborosilicate (62% 0486 adjusting the viscosity of said slurry, preferably by Al-O, 24% SiO, 14% BO); and FRCI-20 (having a com adding thickening agent, position of about 78% wt. silica (SiO) and about 22% wt. 0487 adding a dispersant; aluminoborosilicate (62% Al-O, 24% SiO, 14% BO). 0503. In a preferred embodiment, the components of the 0488 adding the slurry to a mold; inorganic fibers consists, or consists essentially of fibrous 0489 removing water the slurry to form a green billet; silica, alumina fiber, and aluminoborosilicate fiber. In this 0490 removing the green billet from the mold; embodiment, the fibrous silica comprises approximately 0491 drying the green billet in oven, preferably drying at 50-90(%) percent of the inorganic fiber mix, the alumina fiber a temperature of about 250° F to about 500° F.; and comprises approximately 5-50(%) percent of the inorganic US 2008/01 12865 A1 May 15, 2008 39 fiber, and the aluminoborosilicate fiber comprises approxi 0510 Another suitable material is Fibrous Refractory mately 10-25(%) percent of the inorganic fiber mix. The Ceramic Insulation (FRCI). In one embodiment, AETB is fibers used to prepare the substrate of the present invention made from aluminaboriasilica (also known as alumina-boria may have both crystalline and glassy phases in certain silica, aluminoborosilicate, and aluminoboriasilicate) fibers, embodiments. silica fibers, and alumina fibers. One commonly known appli 0504. Other suitable fibers include aluminoborosilicate cation for AETB is as an exterior tile on the Space Shuttle, fibers preferably comprising aluminum oxide in the range ideal for shuttle re-entry. AETB has a high melting point, low from about 55 to about 75 percent by weight, silicon oxide in heat conductance, and coefficient of thermal expansion, abil the range from less than about 45 to greater than Zero (pref ity to withstand thermal and vibrational shock, low density, erably, less than 44 to greater than Zero) percent by weight, and very high porosity and permeability. and boron oxide in the range from less than 25 to greater than 0511. In one embodiment, a first component of AETB is Zero (preferably, about 1 to about 5) percent by weight (cal alumina fibers. In preferred instances of the present invention, culated on a theoretical oxide basis as Al2O, SiO, and BOs, the alumina (Al-O or aluminum oxide, e.g., SAFFIL), is respectively). The aluminoborosilicate fibers preferably are typically about 95 to about 97 weight percent alumina and at least 50 percent by weight crystalline, more preferably, at about 3 to about 5 weight percent silica in commercial form. least 75 percent, and most preferably, about 100% (i.e., crys In other embodiments, alumina having a lower purity are also talline fibers). Sized aluminoborosilicate fibers are commer useful, e.g., 90%, 92%, and 94%. In other embodiments, cially available, for example, under the trade designations alumina having a higher purity are also useful. Alumina can “NEXTEL312 and “NEXTEL 440 from the 3M Company. be produced by extruding or spinning. First, a solution of Further, suitable aluminoborosilicate fibers can be made as precursor species is prepared. A slow and gradual polymer disclosed, for example, in U.S. Pat. No. 3,795.524, which is ization process is initiated, for example, by manipulation of incorporated herein by reference in its entirety. pH, whereby individual precursor molecules combine to form 0505 Additional suitable fibers include aluminosilicate larger molecules. As this process proceeds, the average fibers, which are typically crystalline, comprising aluminum molecular weight/size increases, thereby causing the Viscos oxide in the range from about 67 to about 77, e.g., 69, 71, 73 ity of the solution to increase with time. At a viscosity of about and 75, percent by weight and silicon oxide in the range from ten centipoise, the solution becomes slightly adhesive, allow about 33 to about 23, e.g., 31, 29, 27, and 25, percent by ing fiber to be drawn or spun. In this state, the fiber may also weight. Sized aluminosilicate fibers are commercially avail be extruded through a die. In certain embodiments, the aver able, for example, under the trade designation “NEXTEL age fiber diameter ranges from about one to six microns, 550 from the 3M Company. Further, suitable aluminosilicate although larger and Smaller diameter fibers are also suitable fibers can be made as disclosed, for example, in U.S. Pat. No. for the present invention 4.047.965 (Karst et al.), the disclosure of which is incorpo 0512. In one embodiment, a second component of an rated herein by reference. AETB is silica fiber. Silica (SiO, e.g., Q-fiber or quartz 0506. In other embodiments, the fibers used to prepare the fiber), in certain embodiments, contains over 99.5 weight Substrate of the present invention comprise C-Al-O with percentamorphous silica with very low impurity levels. Silica YO, and ZrO, additions, and/or c-Al-O, with SiO, added oflower purities, e.g., 90%. 95%, and 97%, are also useful for (forming C.-AlO/mullite) the invention. In certain embodiments, anamorphous silica is 0507 Various specific materials can be used to prepare the used that has a low density (e.g., 2.1 to 2.2 g/cm), high catalytic Substrate. In one embodiment, the material used to refractoriness (1600 degrees Celsius), low thermal conduc prepare a Substrate of the present invention comprises, or tivity (about 0.1 W/m-K), and near Zero thermal expansion. alternatively consists or consists essentially of refractory 0513. In one embodiment, a third component of an AETB silica fibers and refractory aluminumborosilicate fibers. In is aluminaboriasilica fibers. In certain instances, aluminabo another embodiment, the material used to prepare the cata riasilica fiber (3 Al-O.2SiO.B.O., e.g., NEXTEL 312) is lytic substrate comprises refractory silica fibers, refractory typically 62.5 weight percent alumina, 24.5 weight percent grade alumina fibers, and a binding agent, preferably a boron silica, and 13 weight percent boria. Of course, the exact oxide or a boron nitride powder. percentages of the constituents of the aluminaboriasilca may 0508. In one embodiment, the catalytic substrate of the vary. It is largely an amorphous product but may contain present invention comprises, or alternatively consists or con crystalline mullite. Suitable aluminaboriasilica fibers and sists essentially of an alumina enhanced thermal barrier methods of making the same are disclosed, for example, in (AETB) material or a like material known to one of ordi U.S. Pat. No. 3,795.524, the teachings of which are herein nary skill in the art. AETB material is known in the art and incorporated by reference in their entirety. more fully described in Leiser et al., “Options for Improving 0514. Other suitable materials for use as a nSiRF-C in the Rigidized Ceramic Heatshields”. Ceramic Engineering and present invention include: AETB-12 (having a composition Science Proceedings, 6, No. 7-8, pp. 757-768 (1985) and of about 20%. Al-O, about 12% (14% BO, 72%. Al-O. Leiser et al., “Effect of Fiber Size and Composition on 14% SiO, NEXTELTM fiber), and about 68% SiO): AETB-8 Mechanical and Thermal Properties of Low Density Ceramic (having a composition of about 20% Al-O, about 12% (14% Composite Insulation Materials”, NASA CP 2357, pp. 231 BO, 72% Al-O, 14% SiO, NEXTELTM fiber), 68% SiO); 244 (1984), both of which are hereby incorporated by refer FRCI-12 (having a composition of about 78% wt. silica CCC. (SiO), and 22% wt. aluminoborosilicate (62% Al-O, 24% 0509. In another embodiment, the catalytic substrate com SiO, 14% BO); and FRCI-20 (having a composition of prises Ceramic tiles. Such as alumina enhanced thermal bar about 78% wt. silica (SiO) and about 22% wt. aluminoboro rier (AETB) with toughened unipiece fibrous insulation silicate (62% Al-O, 24% SiO, 14% BO). (TUFI) and/or reaction cured glass (RCG) coatings. Such 0515. In a preferred embodiment, the components of the materials are known in the art. inorganic fibers consists, or consists essentially of fibrous US 2008/01 12865 A1 May 15, 2008 40 silica, alumina fiber, and aluminoborosilicate fiber. In this 0525 In a preferred embodiment, the fibers are heat embodiment, the fibrous silica comprises approximately cleaned 50-90(%) percent of the inorganic fiber mix, the alumina fiber comprises approximately 5-50(%) percent of the inorganic Wash Fibers fiber, and the aluminoborosilicate fiber comprises approxi 0526 In one step of the present invention, the fibers are mately 10-25(%) percent of the inorganic fiber mix. washed. In a preferred method, the fibers are washed so that 0516 Similar fibers to those fibers of AETB, as described the fibers are substantially free of dust and particles. In one herein, may be utilized in addition to or in the place of the embodiment, the silica fibers are washed in acid to remove AETB fibers. impurities, rinsed, dried, and Subsequently heat treated to 0517 Fiber production via melting can be performed in impart structural integrity. two general methods. The first method involves a combina tion of centrifugal spinning and gaseous attenuation. A glass Chop Fibers stream of the appropriate viscosity flows continuously from a 0527. In another step of the present invention, the fibers furnace onto a spinner plate rotating at thousands of revolu are chopped. Fiber for use in the present invention can typi tions per minute. Centrifugal forces project the glass outward cally be obtained as bulk or chopped fiber. Methods of chop to the spinner walls containing thousands of holes. Glass ping fibers are known in the art. Most methods are continuous passes through the holes, again driven by centrifugal force, processes capable of handling multiple fibers or strands and is attenuated by a blast of heated gas before being col simultaneously. Typically, the product is fed between a set of lected. rotating wheels or drums, one of which Supports regularly 0518. In the second melting technique, molten gas is fed spaced cutting blades. As the fiber is drawn through the cutter, into a heated tank whose bottom surface is perforated by it is chopped to length. Although specific manufacturing hundreds orthousands of holes, depending on the application. details remain proprietary for forming a blank from the Glass flows and is drawn through these holes, forming indi chopped fiber, the art typically involves one of two production vidual fibers. The fibers are merged into strands and collected mechanisms: melting and sol gel. Preferably, the fibers are on a mandrel. heat treated before the final chopping. 0519. In one embodiment, the AETB fiber mix in the 0528 Preferably, the fibers are then chopped to size. Suit slurry preferably comprises three ingredients including able lengths of the fibers include, but are not limited to, about fibrous glass, alumina fiber, and aluminaboriasilica fibers. 0.1, 0.2,0.3, 0.4,0.5, or 0.6 inches. Other suitable lengths The fibrous silica will comprise approximately 50-90 percent include /8", 4", and /2". It is preferred that the fibers are of the inorganic fiber mix; the alumina fiber will comprise relatively uniform in size. In another embodiment, the fibers approximately 5-50 percent of the inorganic fiber mix; and that compose the catalytic Substrate or the filtering Substrate the aluminaboriasilica will comprise approximately 10-25 are an average/4 inch (approximately 1 hundredth of a meter) percent of the inorganic fiber mix. In other embodiments, the in length and about one to 12 microns in diameter, alterna slurry comprises any mixture offibers that can be used make tively, one to six, or 10 to 12 microns with a median fiber diameter of three microns. In a preferred embodiment, par a Substrate according to the invention as described above. ticulate material is not added as it may clog pore space. 0520. In a preferred embodiment, the fibrous component Suitable fibers for use in the present invention are available of the substrate is a mixture of 64% amorphous silica, 21% commercially, e.g., from 3M. Of course, in other embodi alumina, and 15% aluminaboriasilica fiber, with trace amounts, e.g., 0.3 to 1.0 mg/m, of a surface active agent ments, longer fibers are used. employed to aid in the dispersion of bulk fiber in the slurry Slurrying prior to and during casting. 0521. In one embodiment, the fibers in the slurry are only 0529. In another step of the process of the invention, a primarily inorganic fibers. Preferably, in one embodiment, slurry comprising the fibers is prepared. Rather than extrud the present invention does not use any carbon information of ing a ceramic or wrappingayarn or fabric around a perforated the substrate. tube, the Substrate may be made by a commonsol-gel process. This is accomplished by first pulling (via a vacuum or gravity 0522 Alumina-Zirconia fibers may be added to the inor drawn) a well mixed sol of inorganic fibers and colloidal ganic fiber mix as a fourth component or replacement com solution into a fiber mold which creates the sol blank or green ponent for other fibers. billet or billet. 0530 Alternatively, a squeeze-cast pressurizing process Mix Fibers may be used where pressure is reduced to negative value or a 0523. In one step of an embodiment of the present inven vacuum process. The vacuum process allows the inorganic tion, the fibers are mixed. Any number of known methods of fiber blank to be formed with super low densities while main mixing the fibers can be used to mix the fibers. An example is taining its strength. The sol-gel process in conjunction with high-shear mixing which can be employed. the pressurized process or vacuum process helps to produce exceptionally low densities, which is extremely beneficial to Heat Fibers the filtration of particulates. 0531. The fibers are blended together in a slurry. In certain 0524. In one step of the present invention, the fibers are embodiments, a slurry may contain 1 to 2 weight percent heated according to known methods. The fibers are first solids and is nearly as fluid as water. Alternatively, the slurry heated to allow for the fibers to be more evenly chopped. The may contain from about 0.5 to about 5 weight percent solids. heat-treated fibers are washed to remove all of the dust, Other weight percentages are acceptable as well, as is known debris, and loose particles, leaving only the fibers to process. in the art. US 2008/01 12865 A1 May 15, 2008

0532. The chopped fibers are mixed together in a slurry tic. Other suitable materials include aluminum, PLEXI using a high-shear mixer. Preferably, deionized water is used GLAS, and other synthetic materials. Aluminum is very in the slurry to avoid impurities that may act to flux or desta durable over the long term whereas PLEXIGLAS material is bilize the fiber in service. In one embodiment, the slurry can cheap and easy to machine. Suitable permeable Surfaces are be pumped through a centrifugal cyclone to remove shotglass available in the form of a fine metallic mesh screen. Semi and other contaminants, including high soda particles. permeable surfaces larger than about 50 in may under certain 0533. Alternatively, organic fibers or particulate may be circumstances preferably use a backing or Support structure added to the fiber slurry in proportions up to thirty percent by to prevent sagging. weight. During the firing stage of production, the organic 0541. There are embodiments in which an anaerobic, i.e., fiber is volatilized or burned out of the article. Burning the oxygen free, environment may be desirable during casting. fiber leaves a void that allows a path for gases to escape. By The oxygen-free atmosphere creates an environment which varying the type and proportion of polymeric fiber, the per minimizes metal oxidation and uniquely strengthens the fiber meability of the tile can be tailored. bonds. The soaked billet is placed into a chamber, e.g., a large plastic bag, filled with ammonia gas. Ammonia is most com Adjusting Viscosity monly used because of its low cost and availability. Nitrogen 0534. In another embodiment, viscosity is adjusted to a and/or hydrogen gas may also be introduced. Nitrogen is suitable range. A higher viscosity prevents fibers from “lay preferred to hydrogen, since hydrogen is Volatile. In fact, any ing down, i.e., laying flat or becoming oriented only in a gas may be introduced as long as a reducing and oxygen free substantially horizontal direction. Boron nitride may be environment is maintained. Preferably, the gas is provided at added as a thickening agent to coat the fibers in preparation a constant flow until the soaked solbillet has formed into a gel billet. At that point, the gas is turned off and the gel billet is for high-strength sintering. In one embodiment of the present exposed to the open air, allowing the gases to escape. invention, boron nitride is added and aluminaboriasilica fiber 0542 Carbon or organic-based shape-formers may be is not utilized in the slurry. used as hole-forming rods which are introduced into the green Adding Dispersant billet during the molding stage. Upon high temperature sin tering, these rods may disintegrate and leave behind the 0535 In one embodiment, the process comprises adding desired plurality of channels. one or more dispersants to the mixture or slurry. 0536. In one embodiment of the present invention, one or Dewatering the Slurry more surface active agents are added to the slurry during the 0543. In one embodiment of producing the billet, the process of the invention. The Surface active agent is used in slurry is placed in the enclosed mold where at least one quantities of about 5 to about 10 weight percent. The surface dimension is adjustable and at least one wall is semi-perme active agent is employed to aid in the dispersion of bulk fiber able. Compressive force is applied via the adjustable wall and in the slurry prior to and during casting to prevent the fibers water is expelled from the slurry via the semi-permeable wall from bundling together. where fiber collects and felts. Compression is continued until 0537. In one embodiment of the present invention, one or the desired preform, i.e., billet, dimensions are achieved. This more catalysts as described above are added to the slurry. By method is generally limited to simple geometries like blocks adding a catalyst at this stage of the process, a substrate or cylinders. having the catalyst impregnated within the porous material is 0544 Gravity is typically not a sufficient driving force, made. In one embodiment, this configuration eliminates the therefore requiring the use of a vacuum pump. The vacuum need for further washcoating or catalyzing. pump uses very little to no pressure. In some instances, a Molding vacuum is employed to dewater, but the Suction using is very slight. The vacuum is used as a means to speed up the drying 0538. In one embodiment, the slurry is poured into a mold process with great sensitivity to avoid increasing the density. to form a billet. The shape of the mold may take any shape Preferably, only mild vacuum assistance is used. desired. In certain embodiments, the shape of the mold will 0545 More complicated-shaped billets can be prepared by produce a Substrate having a shape Suitable to be used in a an alternative method, for example, in which a head of slurry catalytic converter or particulate filter. For example, the mold is placed and maintained over a semi-permeable mold form. may be in the shape of a cylinder. Alternatively, the mold is in Low pressure is established outside the permeable form via the shape of a pentagon. Preferably, the slurry is not allowed the vacuum pump. The differential pressure drives water to settle in the mold because the fibers may lay down. In one through the permeable form where fiber collects and felts. embodiment, a vacuum Suction method is employed to keep The differential pressure is sustained until the desired thick the fibers from settling down and to maintain uniform poros ness is achieved. This process is Suited to applications where ity and density of the material throughout the billet. The the desired substrate is highly curved, as billets can be pro vacuum Suction technique may be employed from any num duced near-net-shape or close to their final form. ber of directions to control the fiber arrangement and density 0546. Injecting or mixing multiple (two or more) slurry with the green billet. recipes and varying the vacuum rate of pull (a plurality of 0539. By way of example, a billet of the material of the times) provides a billet with some areas denser than others catalytic or filtering Substrate is produced in a mold of 24 and/or areas with different physical properties. The billets can inches by 24 inches (576 in 2)x4 inches having rounded have graduated or different layers or cores with different corners. Of course, billets may be produced of larger or chemical compositions and densities. The billets can have one Smaller sizes. ora plurality of Zones, each with a unique shape, location, and 0540. The material of the mold can be any material that is physical properties as needed. Each Zone can change as stable with water, including but not limited to, metal or plas needed for changing the strength, heat or electrical conduc US 2008/01 12865 A1 May 15, 2008 42 tivity, catalyst adhesion capability, thermal expansion, vibra techniques and methods, such as those disclosed in U.S. Pat. tional or thermal shock, weight, porosity and permeability, No. 3,549,473, the teachings of which are incorporated herein Sound dampening, or any other preferable property. by reference in their entirety. 0547. By using different slurry recipes and molding tech niques, the billets can also be layered. In addition, the billet is Drying the Green Billet (Sintering) not restricted only to parallel planar layers, such as layers on 0553. In another step of an embodiment of the present a cake, but the billets can be formed with horizontal, angled, invention, the green billet is heat cured. The temperature for spherical, pyramidal, and free-form layers, or any other con heat-curing, or sintering, is generally a higher temperature figuration known in the art. It should also be noted that the than that used for drying the green billet. In one embodiment, density of the billet could be chemically and physically the temperature is incrementally increased over one or more altered, if desired, during this process. hours, preferably several hours, until the desired temperature 0548. The billets can also be formed by placing a plurality is reached. In one embodiment, the oven is pre-warmed and of billets, of different chemistry and in any configuration, incrementally heated to approximately 2000-2500°F. Other whether cured or uncured, inside or within another billet. The temperatures known in the art are suitable. core billets can be manually placed into the billet or injected 0554. In a preferred embodiment, after gelling the binder, into the core. The result is a core or a plurality of cores of less the billet is cured by heating the billet to about 200 degrees or more density. The shape or form of these cores and billets Fahrenheit for about four hours, and then slowly increasing is unlimited as is the combination of layering the cores. Cores the temperature to about 600 degrees Fahrenheit over about a may even be created inside cores. The process can be repeated five hour period. After achieving and maintaining the maxi an unlimited number of times as needed yielding a unique mum temperature, the billet is quickly quenched. The end number of combinations of billets in unlimited shapes. result is a rigid inorganic fiber billet. Once again, the process of heat curing the blanks can vary in the temperatures used, Drying the Green Billet length of time to cure, the temperature and time of quenching, 0549. In one step of an embodiment, the slurry in the mold the temperature incremental increases, and the incremental is oven-dried long enough to dewater, i.e., drive off any water temperature increase timing. it may contain. Water can be drained out by gravitational 0555 Billets are fired to supply the necessary energy to forces. Slight vacuum assistance may be utilized. Other meth sinter fiber-to-fiber contacts, thereby forming bonds that ods known in the art can of course be used. impart strength to the Substrate. For example, strength can be increased by increasing the number of fiber-to-fiber contacts. Remove Green Billet from Mold and Drying Green Billet Increasing the number of contacts increases density and tor tuosity. The more tortuous a pore network becomes, the lower 0550. In one step of an embodiment of the invention, the the permeability. Sintering does not cause the fibers to melt green billet is removed from the mold. Generally, the billet together, but instead binds them chemically. The billet is can be removed when it is dry enough to handle. Alterna progressively heated in a high temperature furnace. The billet tively, the billet is removed when it is dry enough to be is pre-warmed and then incrementally heated to approxi manipulated by a machine. mately 2000 to 2500 degrees Fahrenheit until a desired den 0551 For example, when the billet is dry enough to be sity and fusion are obtained. Secondary chemicals such as the handled, it is removed from the mold. The billet is then dried thickening agent are combusted away in preferred embodi in an oven. A low enough temperature is used so as to com ments. A substrate comprising, or alternatively consisting of plete dewatering process and permit fibers to remain Substan or consisting essentially of the sintered fibers remains. tially in their intended configuration. Most preferably, the 0556. In a preferred embodiment, the viscosity (thicken temperature is sufficient to dry the billet as required but insuf ing agent) chemicals and dispersant are combusted away. ficient to cause any or Substantially any sintering of the billet. 0557. In other embodiments, multiple curing steps are per In another preferred embodiment, a temperature of about 250 formed. This can be done to increase hardness of the sub to 500 degrees Fahrenheit is used in this step. In a further Strate. embodiment, the billet is dried at a temperature of about 180° 0558. The variables in the drying and curing processes can C. for about 2 to about 6, preferably about 4 hours. Other be adjusted according to the desired density, strength, poros times and temperatures as are known in the art may be used. ity, or permeability, or resistance to high temperatures, of the 0552. A dried billet is then optionally soaked in a sol-gel fiber blank. In certain embodiments, the curing process can binder, preferably an alumina solgel binder, for a period of use a plurality of curing applications and can vary the heating time, e.g., a few days, at various temperatures, as is known in and cooling intervals and approaches. The billet can also be the art, as the billet “wicks’ (i.e., soaks up) the binder solution rapidly cooled to quench or temper the billet. The slurry may into the billet. A suitable binder is known in the art and may be undergo additional heat or other treatments, such as densifi required to impart preform structural integrity as well as to cation coatings or multiple curing and sintering. promote sintering. The billet may utilize a single or multiple binder process to vary the strength and conductivity of the Physical Modification billet. Applying a binder several times will increase the strength of the billet but may also reduce or plug up the pore 0559. In certain embodiments of the process, the billet is spaces. Any suitable binder may be used. The binder may be coated with a catalyst. In one method of applying catalysts to an oxide binder such as SiO, or Al-O. The oxide binder may a substrate, the substrate may be formed from a slurry that also be a glass configuration, a crystalline configuration, or contains catalysts. Other Suitable methods of applying a cata other inorganic binder. A binder may be applied using known lyst may be used. Another advantage of the present invention US 2008/01 12865 A1 May 15, 2008

is that it has been Surprisingly discovered that a catalyst can be 0565. The shaped slug is utilized as a substrate in the applied to the nSiRF-C material using methods that can apply present invention. The Surface area of the Substrate is an catalyst to other materials. important characteristic for catalysis application. Surface 0560. In another embodiment in the present invention, area is the Sumamount of surface that exhaust emissions must catalyst is added to the slurry prior to molding. In this pass across when traveling through an exhaust filter. instance, a catalytic Substrate is formed having the catalyst Increased Surface area translates into more room for chemical reside directly onto the individual fibers that constitute the reactions to take place between pollutants and catalytic and substrate. This method of adding catalyst to the substrate, in thermal processes, making a catalytic converter process certain embodiments, provides an efficient method of dis quicker and more efficient. Speed and efficiency can result in persing catalyst into the core of the catalyst Substrate and not little to no clogging, which can cause failure of the exhaust have the catalyst reside only along the channel walls. In this system. embodiment, a washcoat is not necessary. 0566 In one embodiment, the substrate of the present invention has a gross Surface area of 83.58 square inches per Machining cubic inch. This translates into a much higher area that can be impregnated with precious metals, as compared to the cordi 0561. A billet in the form of a crude block can be cut or erite samples having comparable macrodimensions (e.g., sawed into a specified shape, and then sanded, turned or diameter, length and width). Note, however, that this gross machined into the final desired shaped “slug.” Although the Surface area calculation does not even include the density, composition of the material is very resilient to chemical, heat, porosity, and permeability of the different materials. thermal and vibrational shock, in preferred embodiments, the 0567. In one exemplary embodiment of the present inven hardness is very low. This low hardness permits machining tion, the Substrate is used in an exhaust filter system for a with little or a minimal amount of resistance or wear on tools. diesel engine. The substrate is created using AETB formula Despite the fact that the billet in certain embodiments has a tion and formed in approximately 13"x13'x5" billets with a low hardness and is soft, it is very durable and easy to density between 8 and 25 pounds per cubic foot. From the machine, sculpt, or shape. On a Moh's hardness scale, the billet, a five inch tall cylinder slug which is six inches in material is usually between 0.5 and 1.0 (or 1-22 on the Knoop diameter or an oval right-cylinder slug is cut from the billet hardness scale)—with talc being the softest at 1 (1-22 Knoop using a diamond tipped or tungsten-carbide band saw. This hardness) and diamond being the hardest at 10 (8,000-8,500 slug is further machined to exact tolerances on a spinning Knoop hardness). For example, silicon carbide has a Moh’s lathe (for right circular cylinders) or on a belt sander forming hardness of 9-10 (2,000-2950 Knoop hardness). In relation to the substrate. other known substances, the billet is very soft and effortless to machine or sculpt as Styrofoam or Balsa wood. Preparing Holes and Channels in Substrate 0562. The billet can be shaped, sanded, turned, or 0568. In an embodiment of the present invention, a plural machined, providing unlimited shaping capabilities of slug ity of channels are formed in the filtering or catalytic substrate formation. The machining can range from turning a cylinder Substantially longitudinal to the intended gas flow. The chan onalathe, sawing to shape with a keyholesaw, band saw orjig nels extend through the length of the substrate, either partially saw, Sanding the shape or Smoothing the Surface, or any other or fully. FIGS. 5-14 show schematic diagrams exemplifying method of machining commonly used on other Solid materi certain embodiments of the present invention having a plu als and known in the art. The billet can be machined down to rality of channels. In certain embodiments, the channels very exacting tolerances with the same accuracy as machin extend at an angle to the flow of fluid. ing metals, woods, or plastics. If the billet is castin cylindrical 0569. The inside surfaces of these channels can be chemi molds with the desired diameter of the final shape, the cally coated so as to capture and treat more pollutants in a machining would simply require cutting and Sanding the small volume of substrate. When channels are formed in the cylindrical billet to the desired thickness. This process also Substrate, Smaller diameter channels, e.g., Small channels reduces Substrate loss due to excessive machining, and speeds having 200, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, up the preforming process as well. 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 0563 There many possible frontal and rear surface shapes 2300, 2400, or 2500 cpsi, are preferred to retain a high surface including circular 510, oval 520, and racetrack 530, as shown aca. in FIG. 5. Three-dimensionally, the substrates may be in the 0570. In another embodiment, the channels extend form of a cylinder or a substantially flat disc. Conventional through the entire length of the substrate. Such a substrate has Substrates exist as one of these three designs. Designs with a flow through configuration. squared corners are not as effective. Although easy to 0571 Alternatively, the channels do not extend through machine, square or angular designs have proven to be a trap the entire length of the substrate but extend from about 50% for rust and corrosives, e.g., road salt. Therefore, rounded to about 99% through the length of the substrate. Such a corners are preferable on the frontal surface shape of the slug. substrate is considered a wall-flow configuration. The 0564. The billet or substrate or slug may be shaped by a undrilled portion remaining in the channels of the wall-flow band saw, jigsaw, CNC, or other method known to one of substrate may have a varied thickness. FIG. 8 shows a wall ordinary skill in the art. The slug may be further shaped by a flow pattern substrate 820 according to an embodiment of the hand rub, lathe sanding, belt Sanding, or orbital sanding. present invention with an undrilled portion 840, 845 of varied Airborne particles must be vacuumed to prevent them from wall thickness. In this embodiment, alternating entering clogging the pores of the material. Further, these particles can channels have a wider wall thickness than other entering enter the bearings of the drill press and destroy it, grinding channels as well as the exit channels. However, the varied away and scoring the bearings. The ceramic dust is also very undrilled portion thickness may be configured in any combi fine and can be easily inhaled by operator. nation Such that the entering or exit channels have a thinner or US 2008/01 12865 A1 May 15, 2008 44 thicker undrilled portion, and wherein the all of the undrilled (0578 Rotating the drill bit at a slow rate is preferable. The portions may or may not be substantially similar in thickness. drill bit should rotate at approximately 200 revolutions per The wall thickness is so thin and porous that the exhaust gas minute. Rotating the drill bit at higher rate, Such as about 830 passes from emission entering channels through the walls 10,000 revolutions per minute, may cause the drill bit to melt. into exit channels, trapping emission particulate. The length The drill bit is kept cool throughout the drilling with lubrica between the inner edges 850 and 855 of the undrilled portions tion Such as water, alcohol, or glycerin. is known as a crossover region. Where the undrilled portion 0579. Once the substrate is cut and sanded to final dimen 840 is thicker in some or all entering channels, emission flow sions, channels are cut or drilled into the substrate. In this 830 is likely to go through the channel walls of the substrate exemplary embodiment, the channels are cut using a DPSSL. in the crossover region and exit the substrate 820. The emis Since the substrate is so porous and permeable, the substrate sion flow 830 may still pass through thinner undrilled portion does not need to as thick as conventional filters. In addition, 845. In another embodiment of the present invention, the thinner or Smaller Substrates are less costly to produce undrilled portion of the channel has a selective impregnation because cutting one billet can produce multiple Substrates and of catalysts, such that the amount of catalysts differs from that requires a reduced amount of any coatings or catalysts to be on the channel walls. applied. 0572 The thickness of this undrilled portion is limited. Gas flow increases by increasing the Surface area of the walls Water Drilling with equivalent thicknesses. If the undrilled portion is too 0580. In another embodiment, water cutting (or water thin, it could rupture from excessive backpressure. drilling) is used for forming channels. Water cutting uses a fine spray of water with very high pressure and cuts holes in Mechanical Drilling the substrate. However, the waterjet cannot be stopped during 0573. Once an embodiment of a substrate is cut from the the cutting process to leave a blind hole (i.e., a channel that billet and machined, it can be inserted into a drillingholder for does not go through the Substrate completely). The physical drilling. A plurality of channels can be drilled into the sub characteristics of the water jet limit the size of the channel strate in the direction Substantially parallel to the major axis opening to a diameter no Smaller than the diameter of the jet. of the cylinder and the flow of exhaust emission. The smaller In certain embodiments, a rectangular hole could be created the channel diameter, the more channels can fit into the Sub with the jet. Strate. 0574. In an alternative embodiment, channels are drilled Gas-Drilling into a substrate. The substrate is placed in a metal holder for drilling. The holder can be for example a pair of large metal 0581. In another aspect of the invention, a gas drilling arms that firmly holds the Substrate slug in place and keeps it method is used to prepare the Substrate. Gas-drilling is known from moving while not crushing the substrate. The holder in the art and can be applied to substrates of the present engages the Substrate and holds it steady for drilling. After invention to prepare channels in the Substrate. drilling one side of the substrate, the holder rotates precisely Combing 180 degrees to allow for drilling in the opposite side of the substrate. If the rotation is not precisely 180 degrees, the 0582. In another embodiment, the channels are formed or drilled channels will not be properly aligned or parallel. Fur shaped using a comb process. The comb is a preferably a ther, the pressure at the ingress needs to be substantially metal device with a plurality of tines that can be forced into identical or similar to the pressure at the egress. Preferably, in (e.g., broaching) the Substrate. The combs used for broaching order to ensure parallel walls, the holder must not move the comprise a plurality of tines. Tine length, width, thickness, substrate in an more than 0.0001 inches in any unwanted and shape may be varied according to the desired properties, direction. configurations, and dimensions of the channels. 0575. The channels of the substrate of the invention can be 0583. In certain embodiments, the comb is forced into the prepared using a mechanical drilling process. In one embodi substrate substantially perpendicular to the surface of the ment, computer number control (“CNC) drilling is used, substrate. In other embodiments, the comb is forced into the which is common among machine shops and is the preferred Substrate at an angle to the Surface of the Substrate. Using a method. CNC drilling is much slower and is not as economi comb is a preferred method, in particular for forming blind cally feasible in mass manufacturing environments requiring channels. It is understood that a suitable comb can also be production of thousands of filters per day. CNC drilling per made so that the comb is made of a rows and columns oftines forms with high precision and accuracy. CNC drilling is done e.g., 4x4, or 16 by 16. by making multiple passes with the drill bit. The CNC drills 0584. In general, the comb process comprises repeatedly a little further into the Substrate on each pass, removing forcing the comb into the substrate material a plurality of fibrous material as the bit comes out. times until most or all of the channel is shaped. This process 0576. The drill bit can be tungsten carbide due to its tough is referred to herein as pecking. Optionally the comb may be and brittle nature, or can be a similar material knownto one of removed from the channel after each forcing into so that ordinary skill in the art. excess Substrate material can be cleared from the channel by, 0577. The drill bit penetrates at a feed rate of about ten feet for example, air. It is preferable to prevent fiber build-up perminute. The slow feed rate is necessary in order to prevent during the pecking/broaching steps. Fiber buildup may cause the drill bit from melting. When the drill bit penetrates at a walls to rupture or the entire. To manage this property, a feed rate of twenty-five feet per minute, the drill bit melts. vacuum and/or compressed air can be employed to clear the Also, due to the tremendous pore space, the drill bit has a channels and drill bit surfaces. tendency to “walk’ or move around. A slowerpenetration rate 0585. In one embodiment, the comb is forced into the cures this problem. substrate with a force sufficient to displace or dislodge an US 2008/01 12865 A1 May 15, 2008

amount of substrate material from the channel wall. In a spacer for comb 1600. Shim 1630 has dimensions of 0.010 preferred embodiment, a sufficient amount of force is applied inches wide, 6.000 inches in length, and 0.4375 inches high. to the comb so that the tines extend about 0.1 inches into the 0593 Preferably, at least one screen is provided over the channel. Other suitable values include 0.05 0.15, and 0.2. combs to keep the tines aligned. Preferably, the screens are Preferably, the amount of force applied to form or shape the floating to distribute alignment as needed. Additionally, the channels is an amount Sufficient to form or shape the channel screens are helpful for tines of varying lengths, for example without Substantially damaging the channel wall. The process from about 0.5 inches to about 6.0 inches long. The at least comprises forcing the tines into the Substrate repeatedly until one screen may be located anywhere along the tines. Such as the channels is produced of desired length and shape. floating, spring-loaded, or fixed. The at least one screen may 0586. The shape of the tines dictates the shape of the be floating along the tines. The tines are not affixed to the at channels. For example, a rectangular-shaped tine on the comb least one screen, rather the screens are placed on the tines Such is used to create rectangular shaped channels with a rectan that the screens are adjustable. The at least one screen may be gular shaped channel opening. spring-loaded on the tines. By spring-loading the screen, the pressure of the Substrate against the screen maintains the 0587. A wedge-shaped tine on the comb is used to create distance between the tines at approximately the edge of the wedge-shaped channels. Utilizing a wedge-shaped tine pro substrate. The at least one screen may also be fixed to the duces channels wherein the walls are parallel with a square tines, at any position along the length of the tines. shaped opening. As shown in FIG. 17, a substrate 1700 incor 0594. Another embodiment of the present invention is porates parallel wedge-shaped “blind' channels 1702, i.e., directed to a process of preparing a catalytic or filtering Sub channels with no exit hole. The blind channels 1702 force strate having a plurality of channels, comprising using a comb gases 1704 to pass through the pore space channels walls to peck at the substrate to form the plurality of channels. This prior to exit. process, in preferred embodiments, is a stepwise process. 0588 A four-sided pyramid-shaped tine on the comb is That is, the entire channel is not formed with one insertion of used to create a pyramidal-shaped channel. The walls are the tine of the comb. Rather, the tines of the comb are repeat parallel and opening is Substantially square-shaped. How edly inserted and removed in small increments until the ever, the wall thickness at the channel opening is minimal as desired length of the channel is obtained. Preferably, the the channels meet at a point, rather than being adjoined by a channels are cleared of dislodged substrate material between wall with a flat front. This results in a decrease in frontal each peck or every other peck Surface area, and thus a decrease in backpressure. With four 0595. In another embodiment, the comb process is an sided pyramid-shaped shaped tines, shims are not needed to automated process utilizing machines and/or robots to form separate the combs. In this embodiment, with reference to the channels. FIG. 16, a suitable comb has tines which come to a point rather than have a flat end. Of course, various other shapes of Method of Making Combs tines are encompassed by the present invention. 0596. There are a number of methods of making combs for 0589. A tent-shaped tine on the comb is used to create a use in the present invention. The combs may be made of a polygonal-shaped channel. Frontal Surface area is minimized material including, but not limited to, stainless steel, tung with polygonal-shaped channels. Sten, or key stock. Methods of shaping the comb include laser 0590 Referring to FIG. 16, the dimensions of an exem cutting, water cutting, and electronic discharge machining, or plary comb 1600 are shown according to an embodiment of utilizing other shaping methods available to one of ordinary the present invention. The comb 1600 is approximately 6.000 skill in the art. inches long and 0.0308 inches wide. The comb 1600 com 0597) DPSSL may be used to manufacture combs. Water prises a base 1610 from which a plurality of tines 1620 cutting may also be employed to manufacture the combs. For extend. The base 1610 is 0.4375 inches high. The plurality of example, thirty to forty combs are made with one cutting tines 1620 are 1.250 inches long and 0.0308 inches wide, and using a water cutting process in one embodiment. spaced by 0.010 inches. 0598 Electronic discharge machining (“EDM) is an 0591. In one embodiment of the comb process, the chan alternative method to manufacturing combs. EDM is a ther nels are first formed by a drill bit and are circular. In order to mal erosion process whereby conductive material is removed produce shaped channels with parallel walls, according to one by a series of recurring electrical discharges between an elec embodiment of the present invention, tines of combs broach trode and a conductive workpiece, in the presence of a dielec (i.e., press or stamp) the circular channels to create the shaped tric fluid. EDM may similarly be used on the substrate if the channel. An embodiment of a comb 1500 is shown in FIG.15. substrate is made electroconductive. There are at least two Preferably, broaching is done on a CNC press. The impres types of EDM: (1) ram and (2) wire. sion left behind is shaped channels and channel openings. The 0599. Using the EDM ram, i.e., die sinking, an electrode/ cell wall thickness may be varied as described above. In tool is attached to a ram which is connected to one pole, certain embodiments, the combing process produces a cata usually the positive pole, of a pulsed power Supply. The lytic or filtering Substrate having a channel wall thickness of workpiece is connected to the negative pole. The workpiece is about 4 mils to about 20 mils, preferably about 6 mils to about then positioned so that there is a gap between the workpiece 10 mils. and the electrode. The gap is then flooded with the dielectric 0592. In the comb process, metal combs may be placed in fluid. Once the power supply is turned on, thousands of direct a box called a jig and mounted in the CNC press for broach current, or DC, impulses per second cross the gap, beginning ing. Within the jig, the combs are separated by shims. The the erosion process. The spark temperatures generated can spacing between the combs is a low tolerance, requiring the range from 14,000 degrees to 21,000 degrees Fahrenheit. As combs to be held tightly in the jig to restrict movement during the erosion continues, the electrode advances into the work broaching. Referring to FIG. 16, a shim 1630 is utilized as a while maintaining a constant gap dimension.