| 摘要 |
<p>IMPROVED COOXIDATION PROCESS FOR THE PRODUCTION OF DIMETHYL TEREPHTHLATE Disclosed is an improvement in the cooxidation process for making dimethyl terephthalate (DMT). In the cooxidation process an oxidate comprising monomethyl terephthalate and p-toluic acid is esterified with methanol to form a reaction mixture comprising DMT and methyl p-toluate, methyl p-toluate is separated from the reaction mixture, and p-xylene and said methyl p-toluate are cooxidized in the liquid phase with molecular oxygen to form more oxidate, which is esterified, etc. The improvement comprises separating p-toluic acid from part of the oxidate prior to esterifying the oxidate, and cooxidizing separated p-toluic acid with said p-xylene and said methyl ptoluate. This improvement results in a lesser quantity of oxidate subjected to esterification, and a reduction in the quantity of methyl p-toluate cooxidized with p-xylene.</p> |
