DOCSLIB.ORG

United States Patent Office Patented Jan

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
United States Patent Office Patented Jan 3,636,177 United States Patent Office Patented Jan. 18, 1972 1. 2 it has been found that the disproportionation and trans 3,636,177 methylation reactions of tetramethylbenzenes proceed in PROCESS FOR PRODUCING DURENE Takashi Suzuki and Hiroyuki Iesaka, Niigata, Japan, quite different manners depending upon the type of assignors to Japan Gas Chemical Company, Inc., diluents used. Thus, in particular it was found that in Chiyoda-ku, Tokyo, Japan 5 producing durene by isomerization of isodurene, prehn No Drawing. Filed May 20, 1970, Ser. No. 39,145 itene, or mixtures of tetramethylbenzenes containing Claims priority, application Japan, May 22, 1969, durene in an amount less than that in the equilibrium com 44/39,121 position, it is possible to produce durene without decreas int, C. C07c5/28 ing the rate of isomerization, while effectively suppressing U.S. C. 260-668 A 7 Claims O the disproportionation or transmethylation reaction of tetramethylbenzenes by carrying out the isomerization in the presence of benzene or polymethylbenzenes having 9 ABSTRACT OF THE DISCLOSURE or less carbon atoms. Durene is produced in high yield by isomerizing other According to the present invention, durene is produced tetramethylbenzenes with a HF-BF catalyst in the by isomerization of isodurene, prehnitene, or mixtures of liquid phase in the presence of a diluent comprising ben tetramethylbenzenes in liquid phase in the presence of zene or methyl-substituted benzenes having 9 or less HF-BF3 catalyst. The isomerization is carried out in carbon atoms, whereby suppressing disproportionation and the presence of benzene or methyl-substituted benzenes transmethylation of tetramethylbenzenes. containing 9 or less carbon atoms to suppress the normal 20 ly concurrent disproportionation and transmethylation -nous summon reaction of tetramethylbenzenes. This invention relates to a process for producing The starting material used in the present process may durene by isomerization of isodurene, prehnitene, or mix be isodurene, prehnitene, or mixtures of tetramethylben tures of tetramethylbenzenes. Zenes containing durene in an amount less than that in Durene is an important substance as the basic starting 25 the equilibrium composition. Therefore, the feed material material for the production of synthetic resins and fibers, may be a mother liquor obtained by cooling a mixture and is obtainable by various manufacturing methods. of tetramethylbenzenes containing an almost equilibrium However, in every known method mixtures of tetramethyl amount of durene and separating the crystallized durene benzene isomers are formed so that it is not easy to obtain from said mixture, or it may be a concentrated isodurene essentially pure durene, and also the yield of durene is 30 obtained by extraction with HF-BF as an extractant. greatly reduced due to the formation of the tetramethyl The feedstock can also comprise a mixture of tetra benzene isomers. Therefore, it has been necessary to isom methylbenzenes having not only the aromatic hydrocarbon erize the by-product tetramethylbenzene isomers other fraction having 10 carbon atoms, which is obtained from than durene into durene, and separate the durene selec the catalytic reformate or thermal cracking residue of tively from the reaction mixture thus obtained. 35 petroleum fractions, but also the reaction products ob It is known in the art to isomerize polymethylbenzenes tained by disproportionation reaction or methylation of with an acidic catalyst in the liquid or gaseous phase; how trimethylbenzenes and other reaction products containing ever, disproportionation and transmethylation reactions, tetramethylbenzenes. which give rise to other difficult problems during the As the diluent in the present process, there may be process, occurs concurrently with the isomerization. The 40 used benzene, toluene, o-Xylene, p-Xylene, m-xylene, disproportionation and transmethylation reactions result hemimellitene, pseudocumene and mesitylene, each alone in an undesirable conversion of tetramethylbenzenes to or in combination. When the raw material already con pentamethylbenzenes and hexamethylbenzenes instead of tains the present diluent, as in the case when the mixture durene. This, in turn results in an additional load on the containing tetramethylbenzenes obtained by dispropor separation and purification procedures for obtaining the tionation reaction or methylation as mentioned above, durene produced. it can be used directly as the starting material. The diluent The liquid phase process for isomerizing polymethyl hydrocarbon is used in a proportion of 20 to 200 parts benzenes using a catalyst consisting of hydrogen fluoride (the term "part” used herein means part by mole), pref and boron trifluoride has an advantage in that the catalyst erably 50 to 150 parts per 100 parts of tetramethylben has low temperature activity whereas the solid catalyst 50 Zenes. The use of more than 200 parts of the diluent is of employed in the gaseous phase process does not. U.S. Pat. no advantage. Since the amount of boron trifluoride to be No. 2,784,242 proposed a method for preparation of used as catalyst affects the isomerization rate and dispro durene by isomerizing polymethylbenzenes in the presence portionation rate, as well as the equilibrium composition of a HF-BF3 catalyst. However, this process has no of the tetramethylbenzenes, it must be predetermined ac practical use due to the concurrence of the dispropor 55 curately. The amount of boron trifluoride generally used tionation of polymethylbenzenes. is within the range of 1 to 20 parts, preferably 4 to 13 The use of saturated hydrocarbons, which are inert parts. The use of more than 20 parts of boron trifluoride under a HF-BF atmosphere, has been proposed to sup is undesirable because of its promoting effect on side re press the disproportionation and transmethylation re actions and its deteriorating effect of decreasing the con actions by their dilution effect. However, unlike the case 60 tent of durene in the equilibrium composition. The use in the production of xylenes where a saturated hydro of less than 1 part of boron trifluoride is unpractical be carbon such as n-heptane suppresses the disproportiona cause the isomerization rate becomes so slow that an ex tion reaction, in the case of tetramethylbenzenes, con cessively long time will be necessary before the equi trary to the case the disproportionation or transmethyla librium state is attained. 65 The amount of hydrogen fluoride to be used is gen tion reaction cannot be suppressed by the use of saturated erally within the range of 30 to 300 parts, preferably 50 hydrocarbons as a diluent in the production of durene. to 250 parts. The most suitable amount is determined The object of this invention is to provide a process for relative to the amount of boron trifluoride, because the producing durene by isomerization of tetramethylbenzenes amount of hydrogen fluoride should be within the range while suppressing the occurrence of Side reactions. 70 where the co-existing boron trifluoride will act most ef From the present study on the isomerization reaction of fectively as catalyst, said range being 0.04 to 0.20 mole, tetramethylbenzenes in the presence of HF-BFs catalyst, preferably 0.08 to 0.15 mole of boron trifluoride per mole 3,636,177 3. 4 of hydrogen fluoride. When mole ratios outside of said and analyzed by gas chromatography. The results were as range are used disadvantages such as promotion of the dis shown in Table 1. proportionation or transmethylation reaction of tetrameth ylbenzenes, and suppression of the isomerization rate may EXAMPLES 2-4 be brought about. Under the conditions set forth above, the isomeriza Reactions were carried out in the manner similar to that tion reaction in the present process may reach an equilib in Example 1. The reaction conditions and the analytical rium state in about 30 minutes at a temperature of 80 to results were as shown in Table 1. 120° C., preferably 90 to 110° C. At temperatures below 80° C. the isomerization reaction proceeds without any O inconvenience but somewhat slower and the completion TABLE of reaction is prolonged. At temperatures above 120° C., the increase in the rate of isomerization is accompanied Example------------------------------- i 2 3. 4. by promotion of the disproportionation reaction. As for Feed (moles): Tetramethylbenzene.---------------- 1.00 the pressure, there is no particular limitation. The isom Benzene---------------- 1.00 erization is usually carried out under the autogenous vapor Hydrogen fluoride------ 1.00 O 5 0. Boron trifluoride------------------- 0, 10 pressure at the reaction temperature, which generally Reaction conditions: . ranges from 2 to 20 kg./cm.?. Reaction period (min.)------------- 30 Temperature (C.)----------- - - - - - - 00 8 The equilibrium mixture of tetramethylbenzenes ob Composition of hydrocarbons in re tained in the present process is composed of approximate action product (percent by mole): Benzene. 50. 50. ly 45 percent of durene, 50 percent of isodurene and 5 Toluene. percent of prehnitene, and is distributed between two Xylene Trimethylbenzene.-- immiscible layers, a catalyst phase (HF phase) and a Tetramethylbenzene.--------------- as: hydrocarbon phase. The basicity of tetramethylbenzene Pentamethylbenzene.--------------- Composition of tetramethylbenzene i isomers with respect to hydrogen fluoride and boron tri 25 (percent by mole): fluoride differs widely from each other. Isodurene pre Dureme-----------------------------
Load more

Recommended publications
  • Measuring and Predicting Sooting Tendencies of Oxygenates, Alkanes, Alkenes, Cycloalkanes, and Aromatics on a Unified Scale
    Measuring and Predicting Sooting Tendencies of Oxygenates, Alkanes, Alkenes, Cycloalkanes, and Aromatics on a Unified Scale Dhrubajyoti D. Dasa,1, Peter St. Johnb,1, Charles S. McEnallya,∗, Seonah Kimb, Lisa D. Pfefferlea aYale University, Department of Chemical and Environmental Engineering, New Haven CT 06520 bNational Renewable Energy Laboratory, Golden CO 80401 Abstract Soot from internal combustion engines negatively affects health and climate. Soot emissions might be reduced through the expanded usage of appropriate biomass-derived fuels. Databases of sooting indices, based on measuring some aspect of sooting behavior in a standardized combustion environment, are useful in providing information on the comparative sooting tendencies of different fuels or pure compounds. However, newer biofuels have varied chemical structures including both aromatic and oxygenated functional groups, making an accurate measurement or prediction of their sooting tendency difficult. In this work, we propose a unified sooting tendency database for pure compounds, including both regular and oxygenated hydrocarbons, which is based on combining two disparate databases of yield-based sooting tendency measurements in the literature. Unification of the different databases was made possible by leveraging the greater dynamic range of the color ratio pyrometry soot diagnostic. This unified database contains a substantial number of pure compounds (≥ 400 total) from multiple categories of hydrocarbons important in modern fuels and establishes the sooting tendencies of aromatic and oxygenated hydrocarbons on the same numeric scale for the first time. Using this unified sooting tendency database, we have developed a predictive model for sooting behavior applicable to a broad range of hydrocarbons and oxygenated hydrocarbons. The model decomposes each compound into single-carbon fragments and assigns a sooting tendency contribution to each fragment based on regression against the unified database.
    [Show full text]
  • Aldrich Vapor
    Aldrich Vapor Library Listing – 6,611 spectra This library is an ideal tool for investigator using FT-IR to analyze gas phase materials. It contains gas phase spectra collected by Aldrich using a GC-IR interface to ensure chromatographically pure samples. The Aldrich FT-IR Vapor Phase Library contains 6,611 gas phase FT-IR spectra collected by Aldrich Chemical Company using a GC interface. The library includes compound name, molecular formula, CAS (Chemical Abstract Service) registry number, Aldrich catalog number, and page number in the Aldrich Library of FT-IR Spectra, Edition 1, Volume 3, Vapor-Phase. Aldrich Vapor Index Compound Name Index Compound Name 6417 ((1- 3495 (1,2-Dibromoethyl)benzene; Styrene Ethoxycyclopropyl)oxy)trimethylsilane dibromide 2081 (+)-3-(Heptafluorobutyryl)camphor 3494 (1-Bromoethyl)benzene; 1-Phenylethyl 2080 (+)-3-(Trifluoroacetyl)camphor bromide 262 (+)-Camphene; 2,2-Dimethyl-3- 6410 (1-Hydroxyallyl)trimethylsilane methylenebicyclo[2.2.1]heptane 6605 (1-Methyl-2,4-cyclopentadien-1- 2828 (+)-Diisopropyl L-tartrate yl)manganese tricarbonyl 947 (+)-Isomenthol; [1S-(1a,2b,5b)]-2- 6250 (1-Propynyl)benzene; 1-Phenylpropyne Isopropyl-5-methylcyclohexano 2079 (1R)-(+)-3-Bromocamphor, endo- 1230 (+)-Limonene oxide, cis + trans; (+)-1,2- 2077 (1R)-(+)-Camphor; (1R)-(+)-1,7,7- Epoxy-4-isopropenyl-1- Trimethylbicyclo[2.2.1]heptan- 317 (+)-Longifolene; (1S)-8-Methylene- 976 (1R)-(+)-Fenchyl alcohol, endo- 3,3,7-trimethyltricyclo[5.4.0 2074 (1R)-(+)-Nopinone; (1R)-(+)-6,6- 949 (+)-Menthol; [1S-(1a,2b,5a)]-(+)-2- Dimethylbicyclo[3.1.1]heptan-2-
    [Show full text]
  • Chapter 21 Practice Problems 1
    Chapter 21 Practice Problems 1. Name the following: A) isopropane B) methylpentane C) methylbutane D) n-pentane E) dodecane 2. Name the following: A) n-heptane B) 2-methyl-2-ethylbutane C) 3,3-dimethylpentane D) 2,2-diethylpropane 3. Name the following: A) 2,4-diethylpentane B) 3,5-dimethylheptane C) secondary ethylpentane D) 2,3-dimethyl-2,3-diethylpropane E) none of these 4. In lecture, a professor named a molecule 2-ethyl-4-tert-butylpentane. A student pointed out that the name was incorrect. What is the correct systematic name for the molecule? A) 2-t-butyl-5-methylhexane B) 2-ethyl-4,5,5-trimethylhexane C) 3,5,6,6-tetramethylheptane D) 2,2,3,5-tetramethylheptane E) undecane 5. Structural isomers have A) different molecular formulas and different structures. B) different molecular formulas but the same structure. C) the same molecular formula and the same structure. D) the same molecular formula but different structures. E) none of these 6. How many structural isomers does propane have? A) 3 B) 2 C) 1 D) 5 E) 4 7. The product of ethane undergoing dehydrogenation is called A) propene. B) methene. C) ethene. D) propane. E) none of these 8. Which of the following, upon reacting with oxygen, would form the greatest amount of carbon dioxide? A) n-pentane B) isopentane C) neopentane D) Two of these would form equal amounts. E) All of these would form equal amounts. 9. Which of the following has the lowest boiling point? A) methane B) butane C) ethane D) propane E) All of these have the same boiling point.
    [Show full text]
  • Δ13c of Aromatic Compounds in Sediments, Oils And
    1 δ13C of aromatic compounds in sediments, oils and 2 atmospheric emissions: a review 3 Alex I. Holman a, Kliti Grice a* 4 5 a Western Australia Organic and Isotope Geochemistry Centre, The Institute for 6 Geoscience Research, School of Earth and Planetary Sciences, Curtin University, 7 GPO Box U1987, Perth, WA 6845, Australia 8 9 * Corresponding author 10 Alex Holman: Tel.: +61(0) 8 9266 9723. E-mail address: A.Holman@curtin.edu.au 11 Kliti Grice: Tel.: +61(0) 8 9266 2474. E-mail address: K.Grice@curtin.edu.au 12 13 14 15 16 17 18 19 Abstract 20 This review discusses major applications of stable carbon isotopic 21 measurements of aromatic compounds, along with some specific technical aspects 22 including purification of aromatic fractions for baseline separation. δ13C 23 measurements of organic matter (OM) in sediments and oils are routine in all 24 fields of organic geochemistry, but they are predominantly done on saturated 25 compounds. Aromatic compounds are important contributors to sedimentary 26 organic matter, and provide indication of diagenetic processes, OM source, and 27 thermal maturity. Studies have found evidence for a small 13C-enrichment during 28 diagenetic aromatisation of approximately 1 to 2 ‰, but the formation of polycyclic 29 aromatic hydrocarbons (PAHs) from combustion and hydrothermal processes 30 seems to produce no effect. Likewise, maturation and biodegradation also produce 31 only small isotopic effects. An early application of δ13C of aromatic compounds was 32 in the classification of oil families by source. Bulk measurements have had some 33 success in differentiating marine and terrigenous oils, but were not accurate in all 34 settings.
    [Show full text]
  • Effects of Sulfide Minerals on Aromatic Maturity Parameters
    Organic Geochemistry 76 (2014) 270–277 Contents lists available at ScienceDirect Organic Geochemistry journal homepage: www.elsevier.com/locate/orggeochem Effects of sulfide minerals on aromatic maturity parameters: Laboratory investigation using micro-scale sealed vessel pyrolysis ⇑ ⇑ Alex I. Holman a, , Paul F. Greenwood a,b,c, Jochen J. Brocks d, Kliti Grice a, a Western Australia Organic and Isotope Geochemistry Centre, Department of Chemistry, The Institute for Geoscience Research, Curtin University, GPO Box U1987, Perth, WA 6845, Australia b Centre for Exploration Targeting, University of Western Australia, Crawley, WA 6009, Australia c WA Biogeochemistry Centre, University of Western Australia, Crawley, WA 6009, Australia d Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia article info abstract Article history: Sedimentary organic matter from the Here’s Your Chance (HYC) Pb–Zn–Ag deposit (McArthur Basin, Received 19 December 2013 Northern Territory, Australia) displays increased thermal maturity compared to nearby non-mineralised Received in revised form 28 August 2014 sediments. Micro-scale sealed vessel pyrolysis (MSSVpy) of an immature, organic rich sediment from the Accepted 2 September 2014 host Barney Creek Formation (BCF) was used to simulate the thermal maturation of OM from the HYC Available online 16 September 2014 deposit, and to assess the effect of sulfide minerals on organic maturation processes. MSSVpy at increas- ing temperatures (300, 330 and 360 °C) resulted in increased methylphenanthrene maturity ratios which Keywords: were within the range reported for bitumen extracted from HYC sediments. The methylphenanthrene Micro-scale sealed vessel pyrolysis index ratio from MSSVpy of the BCF sample was lower than in HYC, due to a reduced proportion of meth- Polycyclic aromatic hydrocarbon Thermal maturity ylated phenanthrenes.
    [Show full text]
  • 1,2,4-Trimethylbenzene Transformation Reaction Compared with Its Transalkylation Reaction with Toluene Over USY-Zeolite Catalyst
    1,2,4-Trimethylbenzene Transformation Reaction Compared with its Transalkylation Reaction with Toluene over USY-Zeolite Catalyst Sulaiman Al-Khattaf*, Nasir M. Tukur, and Adnan Al-Amer Chemical Engineering Department, King Fahd University of Petroleum & Minerals Dhahran 31261, Saudi Arabia Abstract 1,2,4-Trimethyl benzene (TMB) transalkylation with toluene has been studied over USY-zeolite type catalyst using a riser simulator that mimics the operation of a fluidized-bed reactor. 50:50 wt% reaction mixtures of TMB and toluene were used for the transalkylation reaction. The range of temperature investigated was 400-500 oC and time on stream ranging from 3 to 15 seconds. The effect of reaction conditions on the variation of p-xylene to o-xylene products ratio (P/O), distribution of trimethylbenzene (TMB) isomers (1,3,5-to-1,2,3-) and values of xylene/tetramethylbenzenes (X/TeMB) ratios are reported. Comparisons are made between the results of the transalkylation reaction with the results of pure 1,2,4-TMB and toluene reactions earlier reported. Toluene that was found almost inactive, became reactive upon blending with 1,2,4-TMB. This shows that toluene would rather accept a methyl group to transform to xylene than to loose a methyl group to form benzene under the present experimental condition with pressures around ambient. The experimental results were modeled using quasi-steady state approximation. Kinetic parameters for the 1,2,4-TMB disappearance during the transalkylation reaction, and in its conversion into isomerization and disproportionation products were calculated using the catalyst activity decay function based on time on stream (TOS).
    [Show full text]
  • Llllllillllllllllillllllllllllllllllllllllllllilllllllllllll
    llllllIllllllllllIllllllllllllllllllllllllllllIlllllllllllllllllllllllllllSOO5223589A United States Patent -- [19] [11] Patent Number: 5,223,589 Kulprathipanja et al. [45] Date of Patent: Jun. 29, 1993 [54] PROCESS FOR SEPARATING DURENE 3.422.848 1/1969 Liebman et a]. ......... .. 137/625.l5 FROM SUBSTITUTED BENZENE 3.706.812 12/1972 De Rosset et a1. 260/674 SA v 3,864,416 2/1975 Campbell et al. .. 260/674 A HYDROCARBOI\S 4.642.397 2/1987 Zinnen et al. .. 568/934 [75] Inventors: Santi Kulprathipanja, Inverness; 4,743.708 5/1988 Rosenfeld et al. ................ .. 585/828 Kenneth K. Kuhnle, St. Charles; Marjorie s. Patton, Darien, all of 111. OTHER PUBLICATIONS , . Chartov et al. Chem. Abstract 92(7) 58328d [73] Asslgnee: UOP’ Des Flames’ 111‘ (l972)-—Abstract only, page unavailable. [21] APPL No-i 872,191 Primary Examiner-Helen M. S. Sneed [22] Filed. Apr. 22, 1992 Assistant Examiner-Nhat D. Phan Attorney, Agent, or Firm-Thomas K. McBride; John F. [51] Int. (31.5 ......................... .. C07C 7/12; C07C 7/00 Spears’ 1L; Jack H_ Hall - [52] US. Cl. .................................. .. 585/828; 585/825; 585/831; 585/853 [57] ABSTRACT [58] Field Of Search .... ........ .. 585/825. 828, 831, 853 The separation Ofdurene in purity from coal tar or . petroleum fractions by an adsorptive chromatographic [56] References cued process and liquid phase with lithium-exchanged X US- PATENT DOCUMENTS zeolite as the adsorbent and liquid aromatic desorbents. 2.985.589 5/1961 Broughton er al. ................ .. 210/34 3.040.777 6/1962 Carson et al. ................ .. l37/625.l5 4 Claims, No Drawings 5,223,589 1 2 scale (deRosset U.S.
    [Show full text]
  • United States Patent [19] [11] Patent Number: 6,147,270 Pazzucconi Et Al
    US006147270A United States Patent [19] [11] Patent Number: 6,147,270 Pazzucconi et al. [45] Date of Patent: Nov. 14, 2000 [54] PROCESS FOR THE PREPARATION OF 5,670,704 9/1997 Hagen et al. ......................... .. 585/471 2,6-DIMETHYLNAPHTHALENE USING A 5,672,799 9/1997 Perego et al. ......................... .. 585/467 MTW ZEOLITIC CATALYST FOREIGN PATENT DOCUMENTS [75] Inventors: Giannino Pazzucconi, Broni; Carlo 2 246 788 2/1992 United Kingdom . Perego, Carnate; Roberto Millini, WO 90/03960 4/1990 WIPO. Cerro al Lambro; Francesco Frigerio, OTHER PUBLICATIONS Torre d’lsola; Riccardo Mansani, Sassari; Daniele Rancati, Porto Torres, “MTW”; internet search record, Dec. 1999. all of Italy Primary Examiner—Marian C. Knode [73] Assignee: Enichem S.p.A., S. Donato Milanese, Assistant Examiner—Thuan D. Dang Italy Attorney, Agent, or Firm—Oblon, Spivak, McClelland, Maier & Neustadt, PC. [21] Appl. No.: 09/281,961 [57] ABSTRACT [22] Filed: Mar. 31, 1999 A highly selective process is described for preparing 2,6 dimethylnaphthalene Which comprises reacting a naphtha [30] Foreign Application Priority Data lene hydrocarbon selected from naphthalene, Apr. 17, 1998 [IT] Italy ............................... .. MI98A0809 methylnaphthalenes, dimethylnaphthalenes, trimethylnaphthalenes, polymethylnaphthalenes or their [51] Int. Cl.7 ................................................... .. C07C 15/12 mixtures With one or more benzene hydrocarbons selected [52] US. Cl. ........................................... .. 585/475; 585/471 from benzene, toluene, Xylenes, trimethylbenZenes, [58] Field of Search ................................... .. 585/475, 471, tetramethylbenZenes, pentamethylbenZene and/or 585/470 heXamethylbenZene, under at least partially liquid phase conditions, in the presence of a Zeolite belonging to the [56] References Cited structural type MTW and optionally in the presence of a U.S.
    [Show full text]
  • Disproportionation of 1,2,4-Trimethylbenzene Over Zeolite NU-87
    Korean J. Chem. Eng., 17(2), 198-204 (2000) Disproportionation of 1,2,4-Trimethylbenzene over Zeolite NU-87 Se-Ho Park, Jong-Hyung Lee and Hyun-Ku Rhee† School of Chemical Engineering and Institute of Chemical Processes, Seoul National University, Kwanak-ku, Seoul 151-742, Korea (Received 27 September 1999 • accepted 30 December 1999) Abstract−The catalytic properties of zeolite NU-87 were investigated with respect to the disproportionation of 1, 2,4-trimethylbenzene and the results were compared to those obtained over H-beta and H-mordenite with 12-mem- bered ring channel system. In the conversion of 1,2,4-trimethylbenzene, the disproportionation to xylene and tetra- methylbenzene is preferred to the isomerization into 1,2,3- and 1,3,5-isomers over all the three zeolites, but this trend is much more pronounced over HNU-87 owing to its peculiar pore structure. Disproportionation reaction is found to proceed within the micropores of HNU-87, whereas isomerization occurs mainly on the external surface. The high selectivity to disproportionation gives more xylenes and tetramethylbenzenes over HNU-87. The detailed descrip- tions for the product distribution are also reported. Key words: NU-87, 1,2,4-Trimethylbenzene, Disproportionation, Isomerization INTRODUCTION EXPERIMENTAL Disproportionation of trimethylbenzene (TMB) to xylene and 1. Catalysts Preparation = tetramethylbenzene (TeMB) is an important process for the indus- H-mordenite (Engelhard, SiO2/Al2O3 45) and H-beta (PQ Corp., = try, mainly due to the increasing demand for p-xylene to be used SiO2/Al2O3 22) used in this study were taken from commercial for the production of polyester resins.
    [Show full text]
  • Trimethylbenzoic Acids As Metabolite Signatures in the Biogeochemical Evolution of an Aquifer Contaminated with Jet Fuel Hydrocarbons
    Journal of Contaminant Hydrology 67 (2003) 177–194 www.elsevier.com/locate/jconhyd Trimethylbenzoic acids as metabolite signatures in the biogeochemical evolution of an aquifer contaminated with jet fuel hydrocarbons J.A. Namocatcata,1, J. Fanga,*, M.J. Barcelonaa,2, A.T.O. Quibuyenb, T.A. Abrajano Jr.c a National Center for Integrated Bioremediation Research and Development, Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor, MI 48109, USA b Institute of Chemistry, University of the Philippines, Diliman, Quezon City 1101, Philippines c Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA Received 24 May 2002; accepted 21 March 2003 Abstract Evolution of trimethylbenzoic acids in the KC-135 aquifer at the former Wurtsmith Air Force Base (WAFB), Oscoda, MI was examined to determine the functionality of trimethylbenzoic acids as key metabolite signatures in the biogeochemical evolution of an aquifer contaminated with JP-4 fuel hydrocarbons. Changes in the composition of trimethylbenzoic acids and the distribution and concentration profiles exhibited by 2,4,6- and 2,3,5-trimethylbenzoic acids temporally and between multilevel wells reflect processes indicative of an actively evolving contaminant plume. The concentration levels of trimethylbenzoic acids were 3–10 orders higher than their tetramethylben- zene precursors, a condition attributed to slow metabolite turnover under sulfidogenic conditions. The observed degradation of tetramethylbenzenes into trimethylbenzoic acids obviates the use of these alkylbenzenes as non-labile tracers for other degradable aromatic hydrocarbons, but provides rare field evidence on the range of high molecular weight alkylbenzenes and isomeric assemblages amenable to anaerobic degradation in situ.
    [Show full text]
  • Title Unusual Aromatic Nitrations
    Unusual Aromatic Nitrations (Commemoration Issue Title Dedicated to Professor Sango Kunichika On the Occasion of his Retirement) Author(s) Suzuki, Hitomi Bulletin of the Institute for Chemical Research, Kyoto Citation University (1972), 50(4): 407-422 Issue Date 1972-11-17 URL http://hdl.handle.net/2433/76436 Right Type Departmental Bulletin Paper Textversion publisher Kyoto University Bull. Inst. Chem. Res., Kyoto Univ., Vol. 50, No. 4, 1972 Unusual Aromatic Nitrations Hitomi S uzu Kt* ReceivedApril 30, 1972 Aromaticcompounds undergo three differenttypes of reactions with nitrating agentsunder ionic conditions;replacement by nitro groupof an atom or groupfrom a ring position(ordinary nitration), reaction on substituentgroups, and addition reactionfollowed by various transformations. The presentsurvey is directedtowards the latter two typesof reactions,which have hithertonot yet been summarizedin chemicalliterature. It includes; 1. Reactionson SubstituentGroups. 1.1 Side-chainNitro-oxylation. 1.2 Side-chainAcetoxylation and Acetamidation. 1.3 Side-chainNitration. 1.4 Reactionson Lateral Nitrogenor OxygenAtoms. 2. Reactionson AromaticRing. 2.1 Acyloxylationand Alkoxylation. 2.2 Oxynitration. 2.3 Formation of UnsaturatedCyclic Ketones. 2.4 NitrativeCondensations. 2.5 Nitrations with Rearrangement. Nitration is one of the most basic reactions in organic chemistry and is widely used for the preparation of nitro compounds which are among the most valuable intermediates in organic synthesis. The compounds to be nitrated may be either aliphatic or aromatic, but the reaction has more significance in aromatic chemistry. Aromatic nitration is the process in which the nitro group replaces an atom or group from a ring position of an aromatic compound. The reaction has already been dealt with by a number of reviews and books)) In recent years, however, several new reactions have come to light which give the results considerably deviated from the ordinary concept of aromatic nitration.
    [Show full text]
  • "Hydrocarbons," In: Ullmann's Encyclopedia of Industrial Chemistry
    Article No : a13_227 Hydrocarbons KARL GRIESBAUM, Universit€at Karlsruhe (TH), Karlsruhe, Federal Republic of Germany ARNO BEHR, Henkel KGaA, Dusseldorf,€ Federal Republic of Germany DIETER BIEDENKAPP, BASF Aktiengesellschaft, Ludwigshafen, Federal Republic of Germany HEINZ-WERNER VOGES, Huls€ Aktiengesellschaft, Marl, Federal Republic of Germany DOROTHEA GARBE, Haarmann & Reimer GmbH, Holzminden, Federal Republic of Germany CHRISTIAN PAETZ, Bayer AG, Leverkusen, Federal Republic of Germany GERD COLLIN, Ruttgerswerke€ AG, Duisburg, Federal Republic of Germany DIETER MAYER, Hoechst Aktiengesellschaft, Frankfurt, Federal Republic of Germany HARTMUT Ho€KE, Ruttgerswerke€ AG, Castrop-Rauxel, Federal Republic of Germany 1. Saturated Hydrocarbons ............ 134 3.7. Cumene ......................... 163 1.1. Physical Properties ................ 134 3.8. Diisopropylbenzenes ............... 164 1.2. Chemical Properties ............... 134 3.9. Cymenes; C4- and C5-Alkylaromatic 1.3. Production ....................... 134 Compounds ...................... 165 1.3.1. From Natural Gas and Petroleum . .... 135 3.10. Monoalkylbenzenes with Alkyl Groups 1.3.2. From Coal and Coal-Derived Products . 138 >C10 ........................... 166 1.3.3. By Synthesis and by Conversion of other 3.11. Diphenylmethane .................. 167 Hydrocarbons . .................. 139 4. Biphenyls and Polyphenyls .......... 168 1.4. Uses ............................ 140 4.1. Biphenyl......................... 168 1.5. Individual Saturated Hydrocarbons ... 142 4.2. Terphenyls......................
    [Show full text]