A method of producing a purified mixed xylene comprising: introducing toluene and methanol to an alkylation reactor (32); reacting the toluene and the methanol in the alkylation reactor (32) to form a hydrocarbon stream (22) comprising a first mixed xylene, wherein the alkylation reactor (32) comprises an alkylation catalyst; separating the hydrocarbon stream (22) into a toluene stream (24) and a separated C.sub.8+ stream (14); introducing the toluene stream (24) to a transalkylation reactor (38) with a transalkylation catalyst to produce a transalkylated stream (17) comprising a second mixed xylene; adding the transalkylated stream (17) to the hydrocarbon stream (22); and separating a C.sub.8 product stream (19) comprising the purified mixed xylene from the separated C.sub.8+ stream (14).

A method of producing a purified mixed xylene comprising: introducing toluene and methanol to an alkylation reactor (32); reacting the toluene and the methanol in the alkylation reactor (32) to form a hydrocarbon stream (22) comprising a first mixed xylene, wherein the alkylation reactor (32) comprises an alkylation catalyst; separating the hydrocarbon stream (22) into a toluene stream (24) and a separated C.sub.8+ stream (14); introducing the toluene stream (24) to a transalkylation reactor (38) with a transalkylation catalyst to produce a transalkylated stream (17) comprising a second mixed xylene; adding the transalkylated stream (17) to the hydrocarbon stream (22); and separating a C.sub.8 product stream (19) comprising the purified mixed xylene from the separated C.sub.8+ stream (14).

Disclosed is a process for making para-xylene from toluene and/or benzene comprising (i) converting toluene and/or benzene to a first product mixture comprising mixed xylenes, (ii) obtaining a xylene mixture from the first product mixture, (iii) separating para-xylene from the xylene mixture, and (iv) transalkylating meta-xylene and/or ortho-xylene with toluene and/or benzene.

Disclosed is a process for making para-xylene from toluene and/or benzene comprising (i) converting toluene and/or benzene to a first product mixture comprising mixed xylenes, (ii) obtaining a xylene mixture from the first product mixture, (iii) separating para-xylene from the xylene mixture, and (iv) transalkylating meta-xylene and/or ortho-xylene with toluene and/or benzene.

In a process for producing para-xylene, a feed stream comprising C.sub.6+ aromatic hydrocarbons is separated into a toluene-containing stream, a C.sub.8 aromatic hydrocarbon-containing stream and a C.sub.9+ aromatic hydrocarbon-containing stream. The toluene-containing stream is contacted with a methylating agent to convert toluene to xylenes and produce a methylated effluent stream. Para-xylene is recovered from the C.sub.8 aromatic hydrocarbon-containing stream and the methylated effluent stream in a para-xylene recovery section to produce a para-xylene depleted stream, which is then contacted with a xylene isomerization catalyst under liquid phase conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream. The C.sub.9+-containing stream with a transalkylation catalyst under conditions effective to convert C.sub.9+-aromatics to C.sub.8−-aromatics and produce a transalkylated stream, which is recycled together with the isomerized stream to the para-xylene recovery section.

In a process for producing para-xylene, a feed stream comprising C.sub.6+ aromatic hydrocarbons is separated into a toluene-containing stream, a C.sub.8 aromatic hydrocarbon-containing stream and a C.sub.9+ aromatic hydrocarbon-containing stream. The toluene-containing stream is contacted with a methylating agent to convert toluene to xylenes and produce a methylated effluent stream. Para-xylene is recovered from the C.sub.8 aromatic hydrocarbon-containing stream and the methylated effluent stream in a para-xylene recovery section to produce a para-xylene depleted stream, which is then contacted with a xylene isomerization catalyst under liquid phase conditions effective to isomerize xylenes in the para-xylene depleted stream and produce an isomerized stream. The C.sub.9+-containing stream with a transalkylation catalyst under conditions effective to convert C.sub.9+-aromatics to C.sub.8−-aromatics and produce a transalkylated stream, which is recycled together with the isomerized stream to the para-xylene recovery section.

Alkyl-demethylation of C2+-hydrocarbyl substituted aromatic hydrocarbons can be utilized to treat one or more of a heavy naphtha reformate stream, a hydrotreated SCN stream, a C8 aromatic hydrocarbon isomerization feed stream, a C9+ aromatic hydrocarbon transalkylation feed stream, and similar hydrocarbon streams to produce additional quantity of xylene products.

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.

Transalkylation processes using catalysts comprising three dimensional 12 membered ring zeolites with a combination of small and large pores are described. These catalysts have increased conversion of alkylphenols to phenol, cresols, and alkylbenzenes from coal-derived liquid streams compared to catalysts consisting of HZSM-5 zeolite.

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.