(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2015/006548 Al 15 January 2015 (15.01.2015) P O P C T

(51) International Patent Classification: AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, COlC l/12 (2006.01) C01C 3/04 (2006.01) BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, C01C 3/02 (2006.01) F22B 1/18 (2006.01) DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KN, KP, KR, (21) International Application Number: KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, PCT/US20 14/046 130 MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, (22) International Filing Date: OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, 10 July 2014 (10.07.2014) SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, (25) Filing Language: English ZW. (26) Publication Language: English (84) Designated States (unless otherwise indicated, for every (30) Priority Data: kind of regional protection available): ARIPO (BW, GH, 61/845,617 12 July 2013 (12.07.2013) US GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, (71) Applicant: INVISTA TECHNOLOGIES S.A R.L. TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, [LU/CH]; Zweigniederlassung St. Gallen, Kreuzacker- EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, strasse 9, 9000 St. Gallen (CH). MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, (72) Inventors: CATON, John, C ; 3360 County Road 419, KM, ML, MR, NE, SN, TD, TG). Yoakum, Texas 77995 (US). OSTERMAIER, John, J.; 2807 Country Club Drive, Orange, Texas 77630-2144 Published: (US). STEINER, William, J.; 530 County Lane, Bridge — with international search report (Art. 21(3)) City, Texas 7761 1-3218 (US). (81) Designated States (unless otherwise indicated, for every kind of national protection available): AE, AG, AL, AM,

(54) Title: MANUFACTURING PROCESS WITH SECOND WASTE HEAT BOILER

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©o FIG. 1 (57) Abstract: Described is a method for the production and recovery of hydrogen cyanide, which includes removing from o a crude hydrogen cyanide stream. The method integrates heat removed from a crude hydrogen cyanide stream into other areas of the hydrogen cyanide recovery process. The crude hydrogen cyanide stream may be passed through a first waste heat boiler and a second waste heat boiler prior to being fed to an ammonia absorber, which produces a hydrogen cyanide rich stream. Hydrogen cyanide is recovered from the hydrogen cyanide rich stream. Equipment fouling with HCN polymer is reduced. HYDROGEN CYANIDE MANUFACTURING PROCESS WITH SECOND WASTE HEAT BOILER

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. App. 61/845617, filed July 12, 2013, the entire contents and disclosures of which are incorporated herein.

FIELD OF THE INVENTION

[0002] The present invention is directed to a process for manufacturing and recovering hydrogen cyanide. In particular, the present invention is directed to improving process efficiency and hydrogen cyanide recovery by using a second waste heat boiler. BACKGROUND OF THE INVENTION [0003] Conventionally, hydrogen cyanide ("HCN") is produced on an industrial scale according to either the Andrussow process or the BMA process, (see e.g., Ullmann's Encyclopedia of Industrial Chemistry, Volume A8, Weinheim 1987, pages 161-163) For example, HCN can be commercially produced by reacting ammonia with a -containing gas and an oxygen-containing gas at elevated temperatures in a reactor in the presence of a suitable catalyst (U.S. Patent No. 1,934,838). HCN exits the reactor at high temperatures and is rapidly quench