Patent ID: 8183424

Claim:
A process for producing xylene by transalkylation of a C 9 + aromatic hydrocarbon feedstock with a C 6 and/or C 7 aromatic hydrocarbon, the process comprising: (a) contacting a C 9 + aromatic hydrocarbon feedstock, at least one C 6 and/or C 7 aromatic hydrocarbon and hydrogen with a first catalyst under conditions effective to dealkylate aromatic hydrocarbons in the feedstock containing C 2 + alkyl groups and to saturate C 2 + olefins formed so as to produce a first effluent, the 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; (b) contacting at least a portion of said first effluent with a second catalyst comprising a second molecular sieve having a Constraint Index less than 3 under conditions effective to transalkylate C 9 + aromatic hydrocarbons with said at least one C 6 -C 7 aromatic hydrocarbon to form a second effluent comprising xylene; (c) contacting at least a portion of said second effluent comprising xylene with a third catalyst comprising a third molecular sieve having a Constraint Index in the range of about 3 to about 12 under conditions effective to crack non-aromatic cyclic hydrocarbons in said second effluent and form a third effluent comprising xylene.