PROCESS OF CATALYTIC ISOMERIZATION NONEQUILIBRIUM MIXTURE OF C-AROMATIC HYDROCARBONS Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes nonequilibrium raw mix comprising xylenes and ethylbenzene said raw mix is selectively isomerized to obtain isomerized product having higher paraxylene content as compared with initial mix by contacting stock in the presence of hydrogen in isomerization zone with catalyst system (wt %) comprising 5-100 crystalline molecular sieve. Catalyst system preferably comprises (wt %): 0.01-2.0 platinum group metal and up to 95 binding agent such as aluminium or silicon oxide or mixtures thereof. Isomerization is carried out at 300-500 C, pressure of 101.3-5065 KPa, volumetric rate of 0.5-10 h h^-1 and hydrogen to hydrocarbon molar ratio of 0.5:1-25:1. Structure surface is enriched with silicon and this increases p-xylene yield as compared with well known processes. EFFECT: more efficient isomerization process. 3 cl, 3 ex, 5 tbl