METHOD FOR SEPARATING PARA-XYLENE BY PREPROCESSING USING SELECTIVE HYDROGENATION AND ACTIVATED EARTH

摘要

PCT No. PCT/FR96/00238 Sec. 371 Date Jan. 27, 1998 Sec. 102(e) Date Jan. 27, 1998 PCT Filed Feb. 14, 1996 PCT Pub. No. WO96/26170 PCT Pub. Date Aug. 29, 1996In a process for the separation of p-xylene from a feed to be treated containing a mixture of xylenes and olefinic impurities, at least a portion of the feed is circulated in an enrichment zone (14) to enrich a first fraction (15) in p-xylene and provide a second fraction (18) which is depleted in p-xylene. The second fraction is circulated in an isomerisation zone (19) and an isomerate (20) is recovered which is recycled to the enrichment zone. At least a portion of the feed to be treated, the isomerate, or a mixture thereof is circulated in at least one selective hydrogenation zone (3) to partially remove the olefinic impurities and thereafter in at least one clay tretment zone (8) to remove additional olefinic impurities. An effluent is recovered which is sent to the enrichment zone.