Method for separating para-xylene and a clay treatment step at least one located upstream of the adsorption zone and the crystallization step at least one high temperature

摘要

In the method for separating para-xylene of very high purity from [summary] xylene isomers feed, selective adsorption step of fraction rich in para-xylene (8), (57) the method, at least one of the high-temperature It includes crystallization step portion of Tsu and (5a), the isomerization process of the fraction is poor in p-xylene and (21), in some cases, if the clay treatment step followed (26), the mother liquor (3) The recycled to (8) Selective adsorption step via distillation step of the treated effluent (28) by. The mother liquor may be introduced into (23) in the distillation apparatus following the isomerization step before being treated clay in the reactor. The crystallization process includes several steps at high temperature, the temperature in one step of one of these stages is a low temperature or a higher temperature than in a separate step. It is applied to the production of paraxylene very pure for the synthesis of terephthalic acid.