Purified terephthalic acid is one of the most important chemical raw materials.p-Xylene oxidation is a solid-liquid phased catalytic reaction process under high temperature and high pressure.The reactor is the core unit of purified terephthalic acid plant

which affects the product yield and quality noticeably.Current traditional control strategy can meet the demands of the industrial operation

but the variation of the key quality indexes-the concentration of 4-carboxybenzaldehyde in crude terephthalic acid and the oxygen content in the exhaust are big

which influence the further optimization of the process.In this paper

in order to solve this problem

a multivariable predictive control strategy fulfilled by the FRONT-Suite software is put forward.After the application

the control performance on the 4-carboxybenzaldehyde concentration in crude terephthalic acid and oxygen content in the exhaust of p-xylene oxidation process are improved obviously.