Patent ID: 6191331
Filing Date: 2001-02-20
Classification: B01J,C07C,Y02P

Abstract:
A process for the production of paraxylene comprising the steps of:(a) selectively precoking a zeolitic catalyst in a catalyst bed by contacting the catalyst with a coke-forming feed at precoking conditions comprising an inlet temperature of from about 300.degree. to about 700.degree. C. and a temperature differential across the bed of the catalyst of between a 3.degree. C. increase and a 4.degree. C. decrease to deposit between about 5 and 40 mass-% carbon on the catalyst and obtain a selectively precoked catalyst; and,(b) disproportionating an aromatics-rich feedstock comprising contacting the feedstock with the selectively precoked catalyst bed in a disproportionation zone at disproportionation conditions to obtain a paraxylene-rich product containing paraxylene in excess of its equilibrium concentration at disproportionation conditions.