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Wo 2012/050748 A2 (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 _ . _ , _ . 19 April 2012 (19.04.2012) WO 2012/050748 A2 (51) International Patent Classification: (81) Designated States (unless otherwise indicated, for every C07C 2/66 (2006.01) C07C 15/04 (2006.01) kind of national protection available): AE, AG, AL, AM, C07C 6/12 (2006.01) B01J 29/48 (2006.01) AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, C07C 15/08 (2006.01) CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, (21) International Application Number: HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, PCT/US201 1/052234 KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, (22) International Filing Date: ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, 20 September 201 1 (20.09.201 1) NO, NZ, OM, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, (25) Filing Language: English TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, (26) Publication Language: English ZM, ZW. (30) Priority Data: (84) Designated States (unless otherwise indicated, for every 12/894,204 30 September 2010 (30.09.2010) U S kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, (71) Applicant (for all designated States except US): UOP ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, LLC [US/US]; 25 East Algonquin Road, P. O . Box 5017, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, Des Plaines, Illinois 60017-5017 (US). EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, (72) Inventors; and SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, (75) Inventors/ Applicants (for US only): BOLDINGH, Ed¬ GW, ML, MR, NE, SN, TD, TG). win P. [NL/US]; UOP LLC, 25 East Algonquin Road, P. O . Box 5017, Des Plaines, Illinois 60017-5017 (US). NE- Published: GIZ, Antoine [US/US]; UOP LLC, 25 East Algonquin — without international search report and to be republished Road, P. O . Box 501 7, Des Plaines, Illinois 60017-5017 upon receipt of that report (Rule 48.2(g)) (US). (74) Agent: WILLIS, Mark R.; UOP LLC, 25 East Algo nquin Road, P. O . Box 5017, Des Plaines, Illinois 6001 7-5017 (US). < o © o- (54) Title: PROCESSES FOR TRANSALKYLATING AROMATIC HYDROCARBONS (57) Abstract: A process for transalkylating aromatic hydrocarbon compounds, the process comprising introducing an aromatic hydrocarbon feed stream and a water source to a transalkylation zone. The feed stream contacts a catalyst in the transalkylation ¾ zone in the presence of water, and produces a reaction product stream comprising benzene and xylene. The invention includes S methods to control the transalkylation process. H0021 14 PROCESSES FOR TRANSALKYLATING AROMATIC HYDROCARBONS STATEMENT OF PRIORITY [0001] This application claims priority to U.S. Application No. 12/894,204 which was filed on September 30, 2010. FIELD OF THE INVENTION [0002] The present invention generally relates to improved processes for transalkylating aromatic hydrocarbon compounds. More particularly the invention relates to aromatic transalkylation processes producing xylenes and benzene. FIELD OF THE INVENTION [0003] The present invention generally relates to improved processes for transalkylating aromatic hydrocarbon compounds. More particularly the invention relates to aromatic transalkylation processes producing xylenes and benzene. DESCRIPTION OF RELATED ART [0004] Xylene isomers ("xylenes") and benzene are produced in large volumes from petroleum by the reforming of naphtha. However, neither the xylenes nor benzene are produced in sufficient volume to meet demand. Consequently, other hydrocarbons are necessarily converted to increase the yield of the xylenes and benzene via processes such as transalkylation, disproportionation, isomerization, and dealkylation. For example, toluene commonly is dealkylated to produce benzene. Alternatively, or additionally, toluene can be disproportionated to yield benzene and C8 aromatics from which the individual xylene isomers are recovered. [0005] More recently, development has been directed at selectively transalkylating heavier aromatics, such as C9+ aromatics, with toluene and/or benzene to increase the yield of xylenes and benzene from aromatics complexes. In this regard, a variety of catalysts have been developed for these processes. For example, a wide range of zeolites, including mordenite, have been disclosed as effective transalkylation catalysts. Shaped catalysts, multiple zeolites, metal H0021 14 modifiers, and treatments such as steam calcination have been described as increasing the effectiveness of the catalysts. [0006] Known catalysts are effective for producing xylenes and benzene. Specifically, catalysts having a sufficient metal function are suitable to convert heavier aromatics, such as C9+ aromatics to xylenes and benzene and provide improved catalyst stability in a transalkylation process. However, in transalkylation processes employing such catalysts, aromatic rings may become saturated or even cleaved resulting in naphthene and acyclic paraffin (non-aromatics) co-production, which can result in a loss of valuable aromatics. Also, because some of the non-aromatics have similar boiling points to benzene (benzene co-boilers), they are not readily removed to achieve a benzene product having a desired purity for commercial applications. Although the benzene co-boilers can be fractionated or extracted with a solvent, such processes are expensive and typically require additional equipment. [0007] Accordingly, it is desirable to provide a transalkylation process that produces a high purity benzene product. In another aspect, it is desirable to provide a transalkylation process to that produces less benzene co-boilers. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims. SUMMARY OF THE INVENTION [0008] It has been discovered that introducing water into a transalkylation zone reduces the production of benzene co-boilers and/or improves the purity of the benzene fraction of the transalkylation reaction product stream. In another aspect, the invention enables control of the purity of a benzene product stream and/or control of the amount of benzene co-boilers relative to benzene in the reaction product stream or fraction thereof. [0009] In an embodiment, the invention is a process for transalkylating aromatic hydrocarbon compounds comprising introducing a water source and the aromatic hydrocarbon compounds to the transalkylation zone. The feed stream is contacted with a catalyst in the transalkylation zone under transalkylation conditions including the presence of water. A reaction product stream comprising benzene and xylene is produced. In an exemplary embodiment, the catalyst comprises an aluminosilicate zeolite component having an MOR framework type, an H00 14 MFI molecular sieve component having a Si/Al2 molar ratio of less than 80, an inorganic oxide binder, and a metal component comprising a metal selected from the group consisting of rhenium, nickel, cobalt, molybdenum, tungsten, tin, germanium, lead, indium, platinum, palladium, and combinations thereof. [0010] In another embodiment, the invention is a method for controlling an aromatic transalkylation process comprising introducing aromatic hydrocarbon compounds and a water source to a transalkylation zone. Contacting the feed stream with a catalyst in the transalkylation zone under transalkylation conditions including the presence of water. Producing a benzene product stream, determining a purity of the benzene product stream, and controlling the introduction of the water source in response to the purity of the benzene product stream. DETAILED DESCRIPTION [0011] The aromatic hydrocarbons to be transalkylated by processes of the invention include alkylaromatic hydrocarbons of the general formula C H R , where n is an integer from 0 to 5 and R is CH3, C2H5, C3H7, or C4H9, in any combination. Non-limiting examples include: benzene, toluene, ethylbenzene, ethyltoluenes, propylbenzenes, tetramethylbenzenes, ethyl- dimethylbenzenes, diethylbenzenes, methylethylbenzenes, methylpropylbenzenes, ethylpropylbenzenes, triethylbenzenes, trimethylbenzenes, di-isopropylbenzenes, and mixtures thereof. The feed stream may comprise lower levels of ortho-xylene, meta-xylene, and para- xylene that are desired products of the process. [0012] As used herein, the term "transalkylation" encompasses transalkylation between and among alkyl aromatics, between benzene and alkyl aromatics, and it includes dealkylation and disproportionation, e.g., of toluene to benzene and xylene. The aromatic hydrocarbons also may comprise naphthalene and other Cio and C aromatics. Herein, hydrocarbon molecules may be abbreviated Cl, C2, C3, ... Cn , where "n" represents the number of carbon atoms in the hydrocarbon molecule. Such abbreviations followed by a "+" is used to denote that number of carbon atoms or more per molecule, and a "-" is used to denote that number of carbon atoms or less per molecule. [0013] Polycyclic aromatics having from 2 to 4 rings are permitted in the feed stream of the present invention. Non-limiting examples include: indanes, naphthalenes, tetralins, decalins, H002 7 4 biphenyls, diphenyls and fluorenes. Indane is meant to define
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