Optimizing the Load Distribution of the p-Xylene Oxidation Process in a Continuous Reactor

The liquid-phase oxidation of p-xylene (PX) is the key step in the purified terephthalic acid (PTA) production technology. With the improved oxidation technology and intensified competition in the PTA industry, it is crucial to develop a more efficient and energy-saving PX oxidation technology. In this work, the oxidation load distribution for two reactors was optimized through the experiment and simulation. The results showed that the temperature of the first reactor has a substantial influence on the overall PTA production. An increase in temperature in the first reactor reduced the impurity content. However, increasing the reactor or crystallizer temperature has little impact on the morphology of solid particles. Furthermore, with a fixed total residence time of the two reactors, extending the residence time of the first reactor has no impact on reducing impurities, while the reduction of impurities is observed in the second reactor.