Abstract: A method (100) is proposed for the manufacture of benzene, in which a first feedstock mixture is formed, which contains alkylated aromatics and hydrogen, and in which the alkylated aromatics contained in the first feedstock mixture are partially converted with the hydrogen contained in the first feedstock mixture to the benzene through hydrodealkylation (33), thereby obtaining a first product mixture, wherein the first product mixture contains the benzene, the unconverted alkylated aromatics, alkanes with one to three carbon atoms formed in the conversion of the alkylated aromatics to the benzene, and the unconverted hydrogen, and wherein at least a part of the alkanes with one to three carbon atoms and of the hydrogen are separated from the first product mixture, thereby obtaining a light-gas fraction.

Abstract: Methods and apparatus for processing hydrocarbons are provided. In one example, a method for processing hydrocarbons includes the step of providing feed stream including toluene, ethylbenzene, mixed xylenes, and C9 hydrocarbons. Ethylbenzene is present in the feed stream in an amount of at least about 20% by weight of total C8 aromatic hydrocarbons present in the feed stream. The method further includes the step of subjecting the feed stream to ethylbenzene conversion to form a benzene-containing product stream that includes benzene.

Abstract: A method of forming mixed xylenes from a heavy reformate using a dealkylation-transalkylation system includes the step of introducing both a heavy reformate containing methyl ethyl benzenes and tri-methyl benzenes and that is sufficiently free of toluene and a hydrogen-containing material into the dealkylation stage such that the heavy reformate and the hydrogen-containing material intermingle and contact the hydrodealkylation catalyst. The dealkylation-transalkylation system includes dealkylation, non-aromatic product gas separations and transalkylation stages. Toluene forms from the reaction of methyl ethyl benzenes and hydrogen in the presence of the hydrodealkylation catalyst. The method also includes the step of introducing a dealkylated heavy reformate into the transalkylation stage such that the dealkylated heavy reformate contacts a transalkylation catalyst, forming a transalkylation stage product mixture includes mixed xylenes.

Abstract: A method of converting hydrocarbons requires contacting a hydrocarbon stream containing alkylated aromatic hydrocarbons with a catalyst of a phosphorus-containing pentasil zeolite in a reactor. The phosphorus-containing pentasil zeolite having a phosphorus content of 7.5% or less by weight of zeolite, a pore volume of at least 0.2 ml/g, and a 27Al MAS NMR spectrum characterized by a peak at or near 50 ppm that is greater than any other peak in said spectrum. A benzene-enriched output stream is recovered from the reactor.

Abstract: A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and shown to be effective catalysts for aromatic transformation reactions. These zeolites are represented by the empirical formula: NanMmk+TtAll-xExSiyOz where “n” is the mole ratio of Na to (Al+E), M represents at least one meta, “m” is the mole ratio of M to (Al+E), “k” is the average charge of the metal or metals M, T is the organic structure directing agent or agents, “t” is the mole ratio of N from the organic structure directing agent or agents to (Al+E), and E is a framework element such as gallium. The process involves contacting at least a first aromatic with the coherently grown composites of TUN and IMF zeotypes to produce at least a second aromatic.

Abstract: Methods are provided for the treatment of a feed stream containing C9 aromatic components to produce mesitylene-containing products. The methods include hydrodealkylating the feed stream to remove C2 and higher alkyl groups from the aromatic components and transalkylating the feed stream to rearrange the distribution of methyl groups among the aromatic components. Disclosed methods also include the treatment of a hydrocarbon feedstock by hydrodealkylation and/or transalkylation in order to produce a hydrocarbon product having an increased mass percentage of mesitylene.

Abstract: The process concerns ethylbenzene conversion and xylene isomerization with a catalyst pretreated by sulfiding.

Abstract: A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula. NanMmk+TtAl1-xExSiyOz where “n” is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, “m” is the mole ratio of M to (Al+E), “k” is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. UZM-44 may be used to catalyze an aromatic transformation process by contacting a feed comprising at least a first aromatic with UZM-44 at hydrocarbon conversion conditions to produce at least a second aromatic.

Abstract: A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula. NanMmk+TtAl1?xExSiyOz where “n” is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, “m” is the mole ratio of M to (Al+E), “k” is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. UZM-44 may be used to catalyze an aromatic transformation process by contacting a feed comprising at least a first aromatic with UZM-44 at hydrocarbon conversion conditions to produce at least a second aromatic.

Abstract: A guard bed or absorber is placed upstream of a transalkylation reactor to avoid deposition of halide and/or halogen species on the catalysts in said reactor.

Abstract: A new configuration of ZSM-5 is provided whereby the crystals have a higher average silica to alumina ratio at the edges of each crystallite than in the centre as determined from a narrow slit line scan profile obtained from SEM/EDX or TEM/EDX elemental analysis. Such ZSM-5 crystals are obtained by a preparation process using L-tartaric acid. The new configuration ZSM-5 provides significantly reduced xylene losses in ethylbenzene dealkylation, especially when combined with silica as binder, and one or more hydrogenation metals selected from platinum, tin, lead, silver, copper, and nickel.

Abstract: Disclosed is a method for selective dealkylation of alkyl-substituted C9+ aromatic compounds using a bimodal porous dealkylation catalyst at a low temperature. The catalyst has a bimodal porous structure including both mesopores and micropores. The catalyst includes a crystalline aluminosilicate and a metal. The catalyst is highly active at a low temperature. According to the method, C9+ aromatic compounds substituted with at least one C2+ alkyl group as by-products formed by xylene production can be selectively dealkylated and converted to BTX, etc. on a large scale within a short time. In addition, the method is an environmentally friendly process entailing reduced waste treatment cost when compared to conventional mesitylene production methods. Therefore, high value-added mesitylene can be separated from low value-added C9+ aromatic compounds at lower cost compared to conventional methods.

Abstract: Process for the catalytic hydrodealkylation alone of hydrocarbon compositions comprising C8-C13 alkylaromatic compounds mixed with C4-C10 aliphatic and cycloaliphatic products which, under the reaction conditions, undergo aromati-zation and subsequent hydrodealkylation, which comprises treating said hydrocarbon compositions in continuous and in the presence of hydrogen, with a catalyst consisting of a ZSM-5 zeolite, as such or in bound form, wherein the Si/Al molar ratio in the ZSM-5 ranges from 5 to 100, modified by means of the platinum-molybdenum couple, at a temperature ranging from 400 to 650° C., a pressure ranging from 2 to 4 MPa and H2/feedstock molar ratio ranging from 3 to 6. The presence of organic compounds containing heteroatoms such as sulphur, nitrogen or oxygen in the feedstock does not at all alter the performances of the catalyst according to the process object of the invention.

Abstract: A process converts ethylbenzene in a C8 aromatic hydrocarbon mixture containing a large amount of non-aromatic hydrocarbons, mainly to benzene, by which the xylene loss is small, the deactivation rate of the catalyst can be reduced, and a high conversion rate to p-xylene can be attained. The process for converting ethylbenzene includes bringing a feedstock containing an alicyclic hydrocarbon(s) in an amount of not less than 1.0% by weight, ethylbenzene and xylene into contact with hydrogen in the presence of a catalyst to convert ethylbenzene mainly to benzene, wherein the catalyst is mainly composed of MFI zeolite and an inorganic oxide(s) and rhenium-supported, and wherein the conversion is carried out at a reaction pressure of not less than 1.0 MPa-G.

Abstract: In a process for producing xylene by transalkylation of a C9+ aromatic hydrocarbon feedstock, the feedstock, at least one C6-C7 aromatic hydrocarbon and hydrogen are supplied to at least one reaction zone containing at least first and second catalyst beds located such that the feedstock and hydrogen contact the first bed before contacting the second bed. The first catalyst bed comprises a first catalyst composition comprising a molecular sieve having a Constraint Index in the range of about 3 to about 12 and at least one metal or compound thereof of Groups 6-10 of the Periodic Table of the Elements, and the second catalyst bed comprises a second catalyst composition comprising a molecular sieve having a Constraint Index less than 3.

Abstract: Process for the catalytic hydrodealkylation alone of hydrocarbons, comprising C8-C13 alkylaromatic compounds, optionally mixed with C4-C9 aliphatic and cycloaliphatic products, which comprises treating said hydrocarbon compositions, in continuous and in the presence of hydrogen, with a catalyst consisting of a ZSM-5 zeolite, as such or in a bound form, wherein the Si/Al molar ratio in the ZSM-5 ranges from 5 to 35, modified with at least one metal selected from those belonging to groups IIB, VIB, VIII, at a temperature ranging from 400 to 650° C., a pressure ranging from 2 to 4 MPa and a H2/charge molar ratio ranging from 3 to 6.

Abstract: A new configuration of ZSM-5 is provided whereby the crystals have a higher average silica to alumina ratio at the edges of each crystallite than in the centre as determined from a narrow slit line scan profile obtained from SEM/EDX or TEM/EDX elemental analysis. Such ZSM-5 crystals are obtained by a preparation process using L-tartaric acid. The new configuration ZSM-5 provides significantly reduced xylene losses in ethylbenzene dealkylation, especially when combined with silica as binder, and one or more hydrogenation metals selected from platinum, tin, lead, silver, copper, and nickel. Further advantages are found if used in combination with a small crystal size ZSM-5.

Abstract: Process for the catalytic hydrodealkylation alone of hydrocarbon compositions comprising C8-C13 alkylaromatic compounds, optionally in a mixture with C4-C9 aliphatic and cycloaliphatic products, including the treatment in continuous of said hydrocarbon compositions, in the presence of water, with a catalyst consisting of a ZSM-5 zeolite as such or in bound form, wherein the molar ratio Si/Al in the ZSM-5 ranges from 5 to 35, modified with at least one metal selected from those belonging to groups IIB, VIB and VIII, at a temperature ranging from 400 to 700° C., a pressure of between 2 and 4 MPa, a molar ratio between water and the charge in the feed to the reactor ranging from 0.0006 to 0.16 (i.e. between 0.01 and 2.5% w/w) and a molar ratio H2/charge of between 3 and 6.

Abstract: This invention is drawn to a process for producing and recovering one or more high-purity xylene isomers from a feed stream having a substantial content of C9 and heavier hydrocarbons. The feed stream is processed to de-ethylate heavy aromatics, fractionated and passed to a circuit comprising C8-aromatic isomer recovery and isomerization to recover the high-purity xylene isomer with lowered energy costs.

Abstract: A catalytic hydrodealkylation/reforming process which comprises contacting a heavy hydrocarbon feedstream under catalytic hydrodealkylation/reforming conditions with a composition comprising borosilicate molecular sieves having a pore size greater than about 5.0 Angstroms and a Constraint Index smaller than about 1.0; further containing a hydrogenation/dehydrogenation component; wherein at least a portion of the heavy hydrocarbon feedstream is converted to a product comprising benzene, toluene, xylenes and ethylbenzene.

Abstract: A catalyst composition and a process for hydrodealkylating a C9+ aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C6 to C8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, a phosphorus oxide and optionally, an acid site modifier selected from the group consisting of silicon oxides, sulfur oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C9+ aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C9+ aromatic compound to a C6 to C8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for converting a hydrocarbon stream such as, for example, gasoline to C6 to C8 aromatic hydrocarbons such as toluene and xylenes are disclosed. The catalyst composition includes an alumina, a silica, and a metal wherein the weight ratio of aluminum to silicon is in the range of from about 0.002:1 to about 0.6:1. The process includes contacting a hydrocarbon stream with the catalyst composition under a condition sufficient to effect the conversion of a hydrocarbon to a C6 to C8 aromatic hydrocarbon. Also disclosed is a process for producing the catalyst composition which includes: (1) contacting a zeolite with an effective amount of an acid under a condition sufficient to effect a reduction in aluminum content of the zeolite to produce an acid-leached zeolite; and (2) impregnating the acid-leached zeolite with an effective amount of a metal compound under a condition sufficient to effect the production of a metal-promoted zeolite.

Abstract: A catalyst composition and a process for hydrodealkylating a C9+ aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C6 to C8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, a phosphorus oxide and optionally, an acid site modifier selected from the group consisting of silicon oxides, sulfur oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C9+ aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C9+ aromatic compound to a C6 to C8 aromatic hydrocarbon.

Abstract: Disclosed herein is a catalyst composition for transalkylation of alkylaromatic hydrocarbons which exhibits the percent conversion of ethyltoluene higher than 50 wt %, is composed of mordenite (100 pbw), inorganic oxide and/or clay (25-150 pbw), and at least one metal component of rhenium, platinum, and nickel, and contains mordenite such that the maximum diameter of secondary particles of mordenite is smaller than 10 &mgr;m. Disclosed also herein is a process for producing xylene by the aid of said catalyst from alkylaromatic hydrocarbons containing C9 alkylaromatic hydrocarbons containing more than 5 wt % ethyltoluene and less than 0.5 wt % naphthalene, in the presence of hydrogen.

Abstract: A catalyst composition and a process for hydrodealkylating a C9+ aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C6 to C8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, and a coke suppressor selected from the group consisting of silicon oxides, phosphorus oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C9+ aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C9+ aromatic compound to a C6 to C8 aromatic hydrocarbon.

Abstract: There is provided a process for producing high-purity meta-xylene by converting a hydrocarbon feedstream comprising at least about 5 wt % ethylbenzene and at least about 20 wt % meta-xylene, over a single molecular sieve catalyst under ethylbenzene conversion conditions sufficient to provide a primary product stream depleted of more than 50% of the ethylbenzene present in the feedstream. The process can further comprise stripping benzene and/or toluene by-products from the primary product stream to provide a secondary product stream comprising at least about 75 wt % mixed ortho-xylene and meta-xylene; and splitting the secondary product stream by removing substantially all of the ortho-xylene present therein to provide a tertiary product stream comprising at least about 95 wt % meta-xylene.

Abstract: A catalyst composition and a process for hydrodealkylating C.sub.9 + aromatic compounds such as, for example, trimethylbenzenes, to C.sub.6 to C.sub.8 aromatic hydrocarbons such as toluene and xylenes are disclosed. The composition comprises an alumina and a silica wherein the weight ratio of aluminum to silicon is in the range of from about 0.005:1 to about 0.25:1. The process comprises contacting, in the presence of the catalyst composition, a fluid which comprises a C.sub.9 + aromatic compound with a hydrogen-containing fluid under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon; and the C.sub.9 + aromatic compound contains at least 9 carbon atoms.

Abstract: Aromatic hydrocarbons are efficiently converted by bringing feedstock containing from 5 to 50% by weight of an aromatic hydrocarbon having an ethyl group and a C.sub.9 alkyl aromatic hydrocarbon into contact with a catalyst capable of disproportionation, trans-alkylation and dealkylation, a secondary particle diameter of a zeolite in the catalyst being 10 .mu.m or less.

Abstract: A catalyst composition, a process for producing the composition and a hydrocarbon conversion process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an acid-treated zeolite having impregnated thereon a metal or metal oxide. The composition can be produced by incorporating the metal or metal oxide into the zeolite. The hydrocarbon conversion process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises a zeolite, a metal oxide, and an activity modifier selected from the group consisting of silicon oxides, sulfur oxides, phosphorus oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A new process for the hydrodealkylation of ethylbenzene and the isomerization of xylenes at low pressure and at a low hydrogen to ethylbenzene mole ratio as well as a low hydrogen to hydrocarbon feed mole ratio using a catalyst comprising (a) HZSM-5 having a particle size less than 1.0 microns, (b) a Group VIII metal such as platinum, and (c) an additional element such as magnesium.

Abstract: A catalyst composition and a process for converting a hydrocarbon stream such as, for example, a C.sub.9 + aromatic compound to C.sub.6 to C.sub.8 aromatic hydrocarbons such as xylenes are disclosed. The catalyst composition comprises an aluminosilicate, and a metal wherein the weight ratio of aluminum to silicon is in the range of from about 0.002:1 to about 0.6:1. The process comprises contacting a hydrocarbon stream with the catalyst composition under a condition sufficient to effect the conversion of a hydrocarbon to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition, a process for producing the composition and a hydrocarbon conversion process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises a zeolite having impregnated thereon an activity promoter selected from the group consisting of molybdenum, molybdenum oxides, lanthanum, lanthanum oxides, and combinations of two or more thereof. The composition can be produced by incorporating the activity promoter into the zeolite. The hydrocarbon conversion process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition, a process for producing the composition and a hydrocarbon conversion process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises a zeolite having incorporated therein a promoter comprising carbon and a metal or metal oxide. The composition can be produced by incorporating a metal compound into the zeolite followed by thermal treatment of the resulting zeolite with a hydrocarbon. The hydrocarbon conversion process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of added sulfur.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, and a acid site modifier selected from the group consisting of silicon oxides, sulfur oxides, phosphorus oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for converting a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises a zeolite, a metal oxide, and optionally a selectivity modifier selected from the group consisting of silicon, sulfur, phosphorus, boron, magnesium, tin, titanium, zirconium, germanium, indium, lanthanum, cesium, oxides thereof and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of sulfur.

Abstract: An improved process for producing xylene from feedstock containing C.sub.9 alkyl aromatic hydrocarbons with the aid of a catalyst capable of disproportionation, rearrangement, and dealkylation, wherein said improvement comprises performing the reaction in the presence of an aromatic hydrocarbon having one or more ethyl groups in an amount of 5 to 50 wt %.

Abstract: A catalyst composition and a process for converting a C.sub.9 + aromatic compound to C.sub.6 to C.sub.8 aromatic hydrocarbons such as xylenes are disclosed. The catalyst composition comprises a zeolite and a metal. The process comprises contacting a fluid stream containing a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the production of C.sub.6 to C.sub.8 aromatic hydrocarbon. Also disclosed is a process for producing the catalyst composition which can comprise: (1) impregnating a zeolite with an effective and coke-reducing amount of a metal compound under a condition sufficient to effect the production of a metal-promoted zeolite and (2) calcining the metal-promoted zeolite.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina and hexavalent chromium oxide. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon are disclosed. The composition comprises an alumina, molybdenum oxide, and zinc oxide. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, a phosphorus oxide and optionally, an acid site modifier selected from the group consisting of silicon oxides, sulfur oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst for the preparation of benzene, toluene and xylene from C.sub.9.sup.+ heavy aromatics consists of zeolite ZSM-5 and .gamma.- or .eta.-Al.sub.2 O.sub.3 as carrier, Re, Sn and Pt or Pd supported on the carrier. Under the conditions of 350.degree.-450.degree. C., 0.5-3.5 MPa, a WHSV of 1-5 h.sup.-1 and a H.sub.2 /HC ratio (v/v) of 500-1200, the catalyst achieves high activity and stability as well as low hydrogen consumption.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, and an acid site modifier selected from the group consisting of silicon oxides, phosphorus oxides, boron oxides, magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A catalyst composition and a process for hydrodealkylating a C.sub.9 + aromatic compound such as, for example, 1,2,4-trimethylbenzene to a C.sub.6 to C.sub.8 aromatic hydrocarbon such as a xylene are disclosed. The composition comprises an alumina, a metal oxide, and a acid site modifier selected from the group consisting of silicon oxides, boron oxides magnesium oxides, tin oxides, titanium oxides, zirconium oxides, molybdenum oxides, germanium oxides, indium oxides, lanthanum oxides, cesium oxides, and combinations of any two or more thereof. The process comprises contacting a fluid which comprises a C.sub.9 + aromatic compound with the catalyst composition under a condition sufficient to effect the conversion of a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon.

Abstract: A composition which comprises a platinum-promoted zeolite and a gallium-promoted zeolite is disclosed. The composition can be used for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbon. Also disclosed is a process for converting a C.sub.9 + aromatic compound to a C.sub.6 to C.sub.8 aromatic hydrocarbons employing the composition.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is isomerized using a two component catalyst system to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to produce a product stream wherein the para-xylene concentration is approximately equal to the equilibrium ratio of the para-isomer. The first catalyst comprises an intermediate pore size zeolite that is effective for ethylbenzene conversion. The first catalyst is preferably silica-bound. The second catalyst comprises an intermediate pore size zeolite, which further has a small crystal size and which is effective to catalyze xylene isomerization. Each of the catalysts of this invention may contain one or more hydrogenation/dehydrogenation component.

Abstract: A catalyst for hydrogenolytic dealkylation comprising rhodium on a crystalline metallo-silicate carrier and a process for hydrogenolytically dealkylating a hydrocarbon mixture mainly comprising alkyl aromatic hydrocarbons in the presence of such a catalyst are disclosed. The catalyst exhibits catalytic activity at low temperatures and high reaction selectivity and has a prolonged duration.

Abstract: Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of added sulfur.