Patent ID: 6528695
Filing Date: 2003-03-04
Classification: C07C,Y02P

Abstract:
A process for the production of at least one isomer of xylene from an aromatic hydrocarbon feedstock with 8 carbon atoms per molecule that comprises orthoxylene, metaxylene, paraxylene, and the ethylbenzene:a) introducing the feedstock into at least one zone for separating xylenes, and recovering a first fraction that is high in desired isomer and a second fraction that is low in desired isomer, comprising the majority of other isomers and ethylbenzene, b) treating at least a portion of said fraction that is low in desired isomer in at least one catalytic zone for isomerization of aromatic compounds with 8 carbon atoms to convert at least a portion of the ethylbenzene into xylenes and recovering an effluent that comprises paraxylene, orthoxylene, metaxylene and ethylbenzene, c) treating a feedstock that comprises at least a portion of said effluent of the isomerization zone, aromatic hydrocarbons with 9 carbon atoms per molecule, and toluene, in at least one catalytic transalkylation zone, to recover an effluent that comprises benzene, toluene, C9-aromatic hydrocarbons, orthoxylene, paraxylene and metaxylene, d) distilling the effluent of the transalkylation zone in at least one distillation zone and drawing off a benzene-rich fraction, a toluene-rich fraction, a xylene-rich fraction and a fraction that contains C9-aromatic hydrocarbons, e) recycling at least a portion of the xylene-rich fraction from the distillation zone to the zone for separating xylenes in a), wherein the catalyst that is used in the isomerization zone b) comprises at least one EUO-structural elite whose crystals are grouped in aggregates that have a grain size with a value of dv,90 less than or equal to 400 microns and at least one metal of group VIII of the periodic table.