Process for co-production and separation of ethylbenzene and para-xylene comprises two adsorption stages and an isomerization stage using an EUO type zeolite

摘要

The process enables the simultaneous production of ethyl;benzene and para-xylene and their separation, purities greater than 99% being attainable. A process for the co-production of para-xylene and ethylbenzene from an aromatic charge containing 8C isomers is claimed. The charge, in the presence of a primary desorber, is contacted with a zeolitic adsorbent in a primary simulated mobile bed adsorption unit A primary fraction (rich in para-xylene) is withdrawn and also a second fraction (R1) (poor in para-xylene and rich in ethylbenzene). R1 is contacted with a second adsorbent in a second simulated mobile bed adsorption unit in the presence of a second desorbent. A third fraction is recovered, comprising practically pure ethylbenzene, and a fourth fraction rich in ortho- and meta-xylene with no ethylbenzene. Part of the fourth fraction is isomerized in the presence of a catalyst and an isomerate is recovered and recycled to the first adsorption unit. The isomerization catalyst is an EUO-type zeolite.