规模化聚酯装置酯化过程的机理模型化

聚对苯二甲酸乙二醇酯(PET)酯化反应体系的热力学物性计算、动力学常数的整定是实现聚酯工业生产装置模型化的2个重要部分。对聚酯酯化过程的各主副反应——酯化反应、缩聚反应、水解反应、醇解反应、二甘醇生成反应进行机理分析和参数比较,确定了聚酯生产全流程模拟的动力学常数的合理范围。通过动力学参数对目标产物对苯二甲酸、二甘醇、乙二醇、PET质量流量影响的灵敏度分析,修正了反应动力学常数使之适应特定的工业装置,结合物性计算方程建立了规模化聚酯装置酯化工段的机理型数学模型。利用不同生产负荷的工业数据对模型进行了验证,其误差在3%以内。

Modeling of esterification process in industrial poly (ethylene terephthalate) plant based on kinetic mechanism

The computation of thermodynamic properties and determination of kinetic parameters are very important for modeling and simulation of industrial continuous poly(ethylene terephthalate)(PET) plant.The elementary reactions involved in the esterification process include the reactions of esterification,polycondensation,hydrolysis,glycolysis and diethylene glycol formation.The reasonable ranges of the kinetic constants of these elementary reactions were investigated.The sensitivity of the mass flow of terephthalic acid,diethylene-glycol,ethylene-glycol,PET to the variations in those kinetic constants was analyzed,thus providing the basis for determining the appropriate model parameters of process modeling.The model of esterification process of PET process was developed based on kinetic mechanism and the re-parameterized UNIFAC model.The model was validated by using the plant data for different capacities.The error between plant data and simulation is less than 3%.