| 摘要 |
An improved production method of aromatic carboxylic acid products of significantly improved yield and quality, the method including oxidizing alkyl aromatic substrates or their partially oxidized intermediates in a catalyst system containing a conventional catalyst and, if deemed necessary, additional components such as a transition metal or lanthanide series metal, in an acetic acid medium, with a feed gas containing both oxygen and carbon dioxide. Since carbon dioxide functions as a co-oxidant along with oxygen in the oxidation reaction, the oxidation reaction proceeds more selectively to produce the carboxylic acid product much faster under milder reaction conditions as compared to the conventional oxidation. The present invention also can be utilized as an effective purification process to produce highly pure terephthalic acid or isophthalic acid by oxydation of impurities such as 4-carboxybenzaldehyde and para-toluic acid or 3-carboxybenzaldehyde and meta-toluic acid which are contaminated in crude terephthalic acid andisophthalic acid products, respectively. |
