Disclosed are a catalyst and a preparation method therefor, the catalyst being able to maintain a high production yield of C8 aromatic hydrocarbons in the process of converting a feedstock containing alkyl aromatics to C8 aromatic hydrocarbons such as mixed xylene through disproportionation/transalkylation/dealkylation while reducing a content of ethylbenzene in the products.

Disclosed are a bifunctional catalyst and a preparation method therefor, the bifunctional catalyst being suitable to produce high-value aromatic hydrocarbons by subjecting alkylaromatic hydrocarbons to a disproportionation/transalkylation/dealkylation reaction while suppressing aromatic loss or subjecting C8 aromatic hydrocarbons to an isomerization reaction while suppressing xylene loss.

Disclosed are a catalyst system and its use in a process for the conversion of a feedstock containing C.sub.8+ aromatic hydrocarbons to produce light aromatic products, comprising benzene, toluene and xylene. The catalyst system comprises (a) a first catalyst bed comprising a first catalyst composition, said first catalyst composition comprising a zeolite having a constraint index of 3 to 12 combined (i) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (ii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table; and (b) a second catalyst bed comprising a second catalyst composition, said second catalyst composition comprising (i) a meso-mordenite zeolite, combined (ii) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (iii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table, wherein said meso-mordenite zeolite is synthesized from TEA or MTEA and having a mesopore surface area of greater than 30 m.sup.2/g and said meso-mordenite zeolite comprises agglomerates composed of primary crystallites, wherein said primary crystallites have an average primary crystal size as measured by TEM of less than 80 nm and an aspect ratio of less than 2.

This invention relates to process for producing biphenyl esters, the process comprising: (a) contacting a feed comprising toluene, xylene or mixtures thereof with hydrogen in the presence of a hydroalkylation catalyst to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluene, wherein the hydroalkylation catalyst comprises: 1) binder present at 40 wt % or less (based upon weight of final catalyst composition), 2) a hydrogenation component present at 0.2 wt % or less (based upon weight of final catalyst composition), and 3) an acidic component comprising a molecular sieve having a twelve membered (or larger) ring pore opening, channel or pocket and a largest pore dimension of 6.0 angstroms or more present at 60 wt % or more, (based upon weight of final catalyst composition); (b) dehydrogenating the hydroalkylation reaction product using a dehydrogenation catalyst to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds; (c) contacting at the dehydrogenation reaction product with an oxidizing gas to convert the methyl-substituted biphenyl compounds to biphenyl carboxylic acids; and (d) reacting the biphenyl carboxylic acids with one or more C.sub.1 to C.sub.14 alcohols to produce biphenyl esters.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

Disclosed are a catalyst and a preparation method therefor, the catalyst being able to maintain a high production yield of C8 aromatic hydrocarbons in the process of converting a feedstock containing alkyl aromatics to C8 aromatic hydrocarbons such as mixed xylene through disproportionation/transalkylation/dealkylation while reducing a content of ethylbenzene in the products.

Methods and corresponding catalysts are provided for conversion of an aromatic feed containing C.sub.8+ aromatics (particularly C.sub.9+ aromatics) to form a converted product mixture comprising, e.g., benzene and/or xylenes. The aromatic feed can be converted in the presence of a catalyst that includes a silica binder, a mixture of a first zeolite having an MEL framework (such as ZSM-11 and/or an MFI framework (such as ZSM-5), and a second zeolite having an MOR framework, such as mordenite, particularly a mordenite synthesized using TEA or MTEA as a structure directing agent, and a metal. The catalyst can further include one or more metals supported on the catalyst.

Methods and corresponding catalysts are provided for conversion of an aromatics feed containing C.sub.8+ aromatics, particularly C.sub.9+ aromatics, to form a converted product mixture comprising, e.g., benzene and/or xylenes. The aromatic feed can be converted in the presence of a catalyst that includes a mixture of a first zeolite having an MEL framework, such as ZSM-11, and a second zeolite having a MOR framework, such as mordenite, particularly a mordenite synthesized using TEA or MTEA as a structure directing agent. The weight ratio of the first zeolite to the second zeolite in the catalyst can be from 0.3 to 1.2, or from 0.3 to 1.1, or from 0.3 to 1.0. The catalyst can further include one or more metals supported on the catalyst, such as a combination of metals.

A catalyst composition comprising (a) carrier comprising (i) 5 to 95 wt % mordenite type zeolite having a mean crystallite length parallel to the direction of the 12-ring channels of 60 nm or less and a mesopore volume of at least 0.10 cc/gram, (ii) 5 to 95 wt % ZSM-5 type zeolite; and (iii) 10 to 60 wt % inorganic binder; and (b) 0.001 to 10 wt % of one or more catalytically active metals, wherein the inorganic binder comprises titania, its preparation and its use in alkylaromatic conversion.

A supported catalyst for preparing light olefin using direct conversion of syngas is a composite catalyst and formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide; and the component II is a supported zeolite. A carrier is one or more than one of hierarchical pores Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2, MgO and Ga.sub.2O.sub.3; the zeolite is one or more than one of CHA and AEI structures; and the load of the zeolite is 4%-45% wt. A weight ratio of the active ingredients in the component I to the component II is 0.1-20. The reaction process has an extremely high light olefin selectivity; the sum of the selectivity of the light olefin comprising ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.