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.

A method of producing a purified mixed xylene comprising: introducing toluene and methanol to an alkylation reactor; reacting the toluene and the methanol in the alkylation reactor to form a hydrocarbon stream comprising a first mixed xylene, wherein the alkylation reactor comprises an alkylation catalyst; separating the hydrocarbon stream into a toluene stream and a separated C.sub.8+ stream; introducing the toluene stream to a transalkylation reactor with a transalkylation catalyst to produce a transalkylated stream comprising a second mixed xylene; adding the transalkylated stream to the hydrocarbon stream; and separating a C.sub.8 product stream comprising the purified mixed xylene from the separated C.sub.8+ stream.

A method of producing a purified mixed xylene comprising: introducing toluene and methanol to an alkylation reactor; reacting the toluene and the methanol in the alkylation reactor to form a hydrocarbon stream comprising a first mixed xylene, wherein the alkylation reactor comprises an alkylation catalyst; separating the hydrocarbon stream into a toluene stream and a separated C.sub.8+ stream; introducing the toluene stream to a transalkylation reactor with a transalkylation catalyst to produce a transalkylated stream comprising a second mixed xylene; adding the transalkylated stream to the hydrocarbon stream; and separating a C.sub.8 product stream comprising the purified mixed xylene from the separated C.sub.8+ stream.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

A process for producing benzene and xylenes comprising introducing hydrocarbon liquid stream to hydroprocessor to yield first gas stream and hydrocarbon product (C.sub.5+); optionally introducing hydrocarbon product to first aromatics separating unit to produce saturated hydrocarbons (C.sub.5+) and first aromatics stream (C.sub.6+); feeding hydrocarbon product and/or saturated hydrocarbons to reformer to produce reformer product, second gas stream, and hydrogen stream; introducing reformer product to second aromatics separating unit to produce a non-aromatics recycle stream and second aromatics stream comprising C.sub.6+ aromatics; recycling non-aromatics recycle stream to reformer; introducing first aromatics stream and/or second aromatics stream to third aromatics separating unit to produce first C.sub.6 aromatics (benzene), C.sub.7 aromatics (toluene), C.sub.8 aromatics (xylenes&ethylbenzene), C.sub.9 aromatics, C.sub.10 aromatics, and C.sub.11+ aromatics; introducing C.sub.7 aromatics, C.sub.9 aromatics, C.sub.10 aromatics, or combinations thereof to disproportionation and transalkylation unit to yield third aromatics stream (benzene and xylenes); and conveying C.sub.11+ aromatics to hydroprocessor.

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.

Increased paraxylene production through the use of a split feed reforming process, wherein hydrotreated naphtha is split into light, middle and heavy fractions. Each fraction is reformed separately to generate streams containing aromatic compounds. These streams can further be processed and can undergo dealkylation, transalkylation, disproportionation, isomerization, and separation steps to maximize paraxylene production. In addition, some streams are recycled or recombined in order to maximize paraxylene production.

Increased paraxylene production through the use of a split feed reforming process, wherein hydrotreated naphtha is split into light, middle and heavy fractions. Each fraction is reformed separately to generate streams containing aromatic compounds. These streams can further be processed and can undergo dealkylation, transalkylation, disproportionation, isomerization, and separation steps to maximize paraxylene production. In addition, some streams are recycled or recombined in order to maximize paraxylene production.

A process for ethylbenzene conversion and xylene isomerization of an alkylaromatic feed mixture is described. A C.sub.8 alkylaromatic feed mixture can be contacted with two catalyst beds successively in the liquid phase in a C.sub.8 aromatic hydrocarbon isomerization zone. The first catalyst comprises a passivated zeolite containing a ten-membered ring channel framework for the conversion of ethylbenzene. The second catalyst comprises UZM-54 zeolite for selective isomerization of the xylenes.