Abstract: The invention concerns a xylenes isomerization process for the production of equilibrium or near-equilibrium xylenes. The process utilizes a catalyst comprising HZSM-5 or MCM-49 and process conditions including a temperature of less than 295° C. and a pressure sufficient to maintain the xylenes in liquid phase. In embodiments, the process can be operated in a continuous mode with ppm levels of dissolved H2 in the feed and in other embodiments in a cyclic mode without the H2 in feed but with periodic regenerations using a feed having low ppm levels of H2.

Abstract: 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.