Transalkylation of Heavy Aromatic Hydrocarbon Feedstocks

摘要

A process for producing xylene comprises contacting a first feed comprising C₉₊ aromatic hydrocarbons and hydrogen with a first catalyst composition comprising a first molecular sieve having a Constraint Index of 3 to 12 and at least one hydrogenation component. The first catalyst composition dealkylates at least part of the C₉₊ aromatic hydrocarbons containing C₂₊ alkyl groups and to saturate the resulting C₂₊ olefins to produce a second feed. The second feed is then contacted with a second catalyst composition under conditions effective to transalkylate at least part of the C₉₊ aromatic hydrocarbons in the second feed to produce a product comprising xylene. The second catalyst composition comprises a second molecular sieve having a Constraint Index less than 3 and a third molecular sieve having a Constraint Index of 3 to 12.