CRYSTALLISATION PROCESS FOR PRODUCING VERY PURE PARAXYLENE

摘要

The invention is a novel energy efficient process to produce high purity paraxylene from a feed comprising at least 55 to 60 wt% paraxylene, wherein a first portion of high purity paraxylene product is obtained in a first crystallization step at about 10 ~F to about 55 ~F without the need for further reslurry and recrystallization, and wherein another portion of the high purity paraxylene product is obtained following a reslurry step which warms crystalline paraxylene obtained from subsequent lower temperature crystallizations to yield a slurry at a temperature of about 10 ~F to about 55 ~F without the need for further refrigeration.