Patent attributes
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 comprising (i) a first molecular sieve having a Constraint Index in the range of about 3 to about 12 and (ii) at least first and second different metals or compounds thereof of Groups 6 to 12 of the Periodic Table of the Elements. Contacting with the first catalyst is conducted 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 comprising a second molecular sieve having a Constraint Index less than 3 under conditions effective to transalkylate C9+ aromatic hydrocarbons with said at least one C6-C7 aromatic hydrocarbon to form a second effluent comprising xylene.
