Patent ID: 7629499
Filing Date: 2009-12-08
Classification: C07C

Abstract:
1. A process producing xylenes by transalkylation of an alkyl-aromatic hydrocarbon feedstock having at least 9 carbon atoms per molecule and being devoid of benzene and toluene except for possible trace amounts, which process consists essentially of: a) a stage (a) introducing said alkyl-aromatic hydrocarbon feedstock at the inlet of a first reaction zone where it is brought into contact with at least a first zeolitic catalyst in the presence of hydrogen to produce by transalkylation, an effluent containing xylenes, benzene and toluene, b) in a separate stage (b) introducing at least a portion of resultant effluent obtained from stage a) and a feedstock that consists essentially of benzene and/or toluene to the inlet of a second transalkylation reaction zone that contains hydrogen and at least a second zeolitic catalyst, to form additional xylenes and c) separating xylenes from at least a portion of resultant effluent obtained from stage b).