Dealkylation and Transalkylation of Heavy Aromatic Hydrocarbons

A process for producing xylene from C9+ aromatic hydrocarbons, the process comprising:

• (a) contacting a feedstock comprising C9+ aromatic hydrocarbons with a first catalyst in the presence of 0 wt. % or more of hydrogen under effective vapor phase dealkylation conditions to dealkylate part of the C9+ aromatic hydrocarbons and produce a first product comprising benzene and C9+ aromatic hydrocarbons;
• (b) contacting at least part of the first product and toluene with a second catalyst in the presence of hydrogen under effective vapor phase toluene disproportionation conditions to disproportionate at least part of the toluene and produce a second product comprising para-xylene, benzene, toluene and C9+ aromatic hydrocarbons;
• (c) contacting at least part of the C9+ aromatic hydrocarbons from the second product and benzene and/or toluene with a third catalyst in the presence of hydrogen under effective C9+ transalkylation conditions to transalkylate at least part of the C9+ aromatic hydrocarbons and produce a third product comprising xylenes;
• and
• (d) separating para-xylene from at least the second product.