Patent ID: 6153790
Filing Date: 2000-11-28
Classification: C07C,Y02P

Abstract:
A method to produce an acid substituted aromatic from an alkyl substituted aromatic, the method comprising the steps of:providing a feed stream comprising a dialkyl substituted aromatic and in an organic acid solvent:contacting the feed stream with an oxidant, the oxidant containing at least 50% by volume oxygen and at an oxygen partial pressure of at least 1 psia, at a temperature between about 80.degree. C. and about 130.degree. C., in the presence of catalyst system comprising zirconium and cobalt, wherein the contacting is done in a stirred tank reactor;removing from the stirred tank reactor a vapor stream comprising the organic acid, water vapor and unreacted oxidant;condensing at least a portion of the organic acid and water from the vapor stream;separating at least a portion of the water from the organic acid back to the stirred tank reactor;returning at least a portion of the condensed organic acid back to the stirred tank reactor;continuously recovering from the stirred tank reactor a product comprising a diacid substituted aromatic;isolating solid crystals of diacid substituted aromatic from the reactor product;recovering from the solid crystals a diacid substituted aromatic having a purity of at least 97% by weight wherein the step of recovering from the solid crystals of diacid substituted aromatics a diacid substituted aromatic having a purity of at least 97% comprises a step of contacting the isolated crystals of diacid substituted aromatic with a first solvent for a time period of between about 5 and about 120 minutes and separating crystals of diacid substituted aromatics from the first solvent and then contacting the separated crystals of diacid substituted aromatic with a second solvent for a time period of between about 5 and about 120 minutes.