US Patent 8481443 Transalkylation of heavy aromatic hydrocarbon feedstocks

In a process for producing xylene by transalkylation of a C9+aromatic hydrocarbon feedstock with a C6 and/or C7 aromatic hydrocarbon, the C9+aromatic hydrocarbon feedstock, at least one C6 and/or C7 aromatic hydrocarbon and hydrogen are contacted with a first catalyst under conditions effective to dealkylate aromatic hydrocarbons in the feedstock containing C2+alkyl groups and to saturate C2+olefins formed so as to produce a first effluent. At least a portion of the first effluent is then contacted with a second catalyst under conditions effective to transalkylate C9+aromatic hydrocarbons with said at least one C6-C7 aromatic hydrocarbon to form a second effluent comprising xylene.