POLYCARBOXYLIC ACID PRODUCTION SYSTEM EMPLOYING ENHANCED EVAPORATIVE CONCENTRATION DOWNSTREAM OF OXIDATIVE DIGESTION

摘要

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. The system employs an evaporative removal step downstream of oxidative digestion. The evaporative removal step removes a portion of the liquid phase and promotes precipitation of certain aromatic impurities. By promoting precipitation of certain aromatic impurities, the amount of the precipitated impurities in the recycled solvent is advantageously reduced.