METHOD OF PRODUCING AROMATIC CARBOXYLIC ACIDS

摘要

An improved production method of aromatic carboxylic acids of significantly improved yields and quality by oxidizing alkyl aromatic substrates or their partially oxidized intermediates by oxygen-enriched gas in a conventional Co-Mn-Br catalyst system containing additional components such as a transition metal or lanthanide metal component in an aliphatic carboxylic acid having 1 SIMILAR 6 carbon atoms. In other words, a decline in reactivity in the later part of the oxidation reaction and the precipitation of a catalyst such as manganese were effectively deterred by means of incorporating one or more than one type of transition or lanthanide metal components selected from such metals as Ce, Zr, Hf, Fe, Cr, and Mo during the oxidation reaction with oxygen-enriched gas. With this invention, pure aromatic carboxylic acids with white color can be obtained with high selectivity and reactivity by oxidation of substrates with oxygen-enriched gas. The oxidation reaction of alkylaromatic substrates proceeds more selectively with a much faster rate to produce aromatic carboxylic acids of improved quality as compared to those of conventional oxidation processes.