A Mathematical Model For Direct Esterification Process Of PET

The continuous process of Terephthalic Acid(PTA) and Ethylene Glycol(EG) is a crucial process of PET production. This process directly makes a great impact on PET quality. Modeling of a direct esterification process is undoubtedly very important for estimating product quality online, deepening the analysis of the reaction process and developing optimal control strategy. Hence, taking an industrial process of Polyethylene Terephthalate(PET) as the object, a mathematical model of direct esterification process of PET is set up based on both the esterification mechanism and the real process conditions. Meanwhile an approach to solve the model has also been introduced.The paper has developed a model for direct esterification process of PET based on the mechanism analysis of the continuous esterification process of PTA and EG. On the condition of reasonable hypotheses, the model involves reaction rate equations, gas-liquid equilibrium, gas-liquid mass transfer equations and mass equilibrium. The results of simulation is close to the commercial practice.The direct esterification process includes the two esterification reactors. So the paper introduces the modeling process and the method of solving the model in detail. Then the paper develops the mathematical model of all esterification process by means of the method of modeling of the first esterification reactor.Furthermore, this paper proves the accuracy of the established model using the esterification process designed data. The output of model is consistent with the designed criterion and also the measured quality merit. Afterwards the paper detailedly analyses the results of the simulation.In the end, this paper also introduces the application of mixed programming for Matlab & VC++ in chemical engineering calculating on account of the complexity of chemical calculation and the computational advantage of Matlab.