Dynamic model is the basis of dynamic optimization in chemical process.In this paper a dynamic model for esterification section of poly(ethylene-terephthalate) （PET） was developed using segment method.Different from other researches

the model considered the interaction between esterification reactor and the column.Dynamic responses of process operating condition were analyzed with basic control strategies.Simulation results show that properties of products such as carboxyl end concentration

degree of polymerization response quickly to step change of feed molar ratio

reactor temperature

pressure and liquid level.Also these step changes significantly affected the changes in gas flow of ethylene glycol and water.Control system plays a significant role in the stability of PET esterification process.