PROCESS FOR SEPARATING P-XYLENE WITH DIETHYL-TOLUENE DESORBENT

摘要

A chromatographic process able to separate para-xylene from C8 isomers and C9 aromatics. In the process, the para-xylene-containing feed mixture is contacted with an X or Y zeolite adsorbent having Group IA or IIA cations, e.g., barium and/or potassium at exchangeable cationic sites. The para-xylene is selectively adsorbed onto the adsorbent. The feed is then removed from the adsorbent and the para-xylene recovered by desorption with diethyltoluene. The C9's and the other xylene isomers in the raffinate, can be separated from this heavy desorbent by fractionation of the raffinate and the desorbent recycled to the process. The preferred desorbents are 2,3-diethyltoluene, 2,5-diethyltoluene and 2,6-diethyltoluene.