Eastman-kodak Company

Judy E Kiefer

Thomas Earl Woodruff

Griffin Ivan Johnson

William V Phillips

The present invention provides an improved process for the purification of crude terephthalic acid which has been produced by the oxidation of para-xylene. The process comprises contacting the crude terephthalic acid with oxygen-containing gas at a temperature of about 190.degree. to 230.degree. C. and a pressure of about 1500 to 3600 kPa in the presence of a solvent comprising an alkanoic acid which is preferably acetic acid. The process further comprises the use of a novel and surprisingly effective catalyst system. The catalyst system comprises cobalt, a bromine source, and pyridine.

Process for the purification of terephthalic acid

The present invention provides an improved process for the purification of crude terephthalic acid which has been produced by the oxidation of para-xylene. The process comprises contacting the crude terephthalic acid with oxygen-containing gas at a temperature of about 190.degree. to 230.degree. C. and a pressure of about 1,850 to 3,600 kPa in the presence of a solvent comprising an alkanoic acid which is preferably acetic acid. The process further comprises the use of a novel and surprisingly effective catalyst system. The catalyst system comprises cobalt, a bromide compound, and samarium, with the samarium being employed at a concentration of about 0.005 to 500 ppm.

Growing community of inventors

Kingsport, TN, United States of America

Judy E Kiefer