The present invention provides a method for producing 1,3-butadiene that is capable of suppressing generation of reaction by-products. The method includes: a step (A) of to obtain a produced gas containing 1,3-butadiene; a step (B) of cooling the produced gas; and a step (C) of separating the produced gas cooled in the step (B) into molecular oxygen and inert gases, and other gases containing 1,3-butadiene, by selective absorption into an absorption solvent. In the method, in the step (A), the raw material gas and a molecular oxygen-containing gas are supplied to a fixed-bed reactor with a composite oxide catalyst containing molybdenum and bismuth; the molar ratio of molecular oxygen to n-butene in the gases is 1.0 to 2.0; and the molar ratio of water vapor to n-butene in the gases supplied to the fixed-bed reactor is not more than 1.2.

Method of making BTX compounds including benzene, toluene, and xylene, including feeding heavy reformate to a reactor containing a composite zeolite catalyst. The composite zeolite catalyst includes a mixture of layered mordenite (MOR-L) comprising a layered or rod-type morphology with a layer thickness less than 30 nm and ZSM-5. The MOR-L, the ZSM-5, or both include one or more impregnated metals. The method further includes producing the BTX compounds by simultaneously performing transalkylation and dealkylation of the heavy reformate in the reactor. The composite zeolite catalyst is able to simultaneously catalyze both the transalkylation and dealkylation reactions.

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.

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 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.

Method of making BTX compounds including benzene, toluene, and xylene, including feeding heavy reformate to a reactor containing a composite zeolite catalyst. The composite zeolite catalyst includes a mixture of layered mordenite (MOR-L) comprising a layered or rod-type morphology with a layer thickness less than 30 nm and ZSM-5. The MOR-L, the ZSM-5, or both include one or more impregnated metals. The method further includes producing the BTX compounds by simultaneously performing transalkylation and dealkylation of the heavy reformate in the reactor. The composite zeolite catalyst is able to simultaneously catalyze both the transalkylation and dealkylation reactions.