SEPARATION METHOD OF PARA-XYLENE OUT OF A HYDROCARBONATE FLOW

摘要

Sepn of p-dialkylaromatic hydrocarbons from mixts. with other isomers by effected by (a) contacting the mixt. with a Ba- and K-exchanged zeolite, esp. having a BaO/K2O molar ratio of 0.6-1.2, to adsorb the p-isomer and (b) desorbing the p-isomer with m- and/or o-difluorobenzene. The zeolite is an X or Y zeolite with a BaO/K2O ratio of 0.9-1.1, and may be composited with an amorphous inorganic oxide. The process may be operated using a simulated moving-bed flow system (esp. countercurrent). Desorption is effected at 20-250 deg.C and a pressure sufficient to maintain liq. phase.