PURPOSE: To efficiently obtain p-xylene useful as e.g. a raw material for polyesters by mixing a feedstock oil containing ethylbenzene, etc., with raffinate followed by treatment under specified conditions to raise the p-xylene concentration of the feed liquor to a p-xylene separation process.
CONSTITUTION: A new feedstock oil containing ethylbenzene and a xylene component composed of p-xylene, m-xylene and o-xylene is mixed with raffinate, and the resultant mixture is fed to a raffinate lsomerization process 103, where an isomerization is carried out, and the xylene component is then distilled and separated in a distillation process 101, and then fed to a p-xylene separation process 102, thus obtaining the objective p-xylene 5. It is preferable that the catalyst for the isomerization process 103 be a deethylation-type lsomerization catalyst and the xylene separation process 102 be of adsorptive separation scheme.
HATANAKA SHIGETO
SHIMIZU KAZUTOMO
SASAKI YOICHI
