连续化DOP非酸催化酯化工序的改造

The reconstruction of continuous DOP esterification using tetrabutyl titanate catalyst

以某厂连续法邻苯二甲酸二辛酯(DOP)装置由5万吨/年扩产至10万吨/年的项目为背景,着重研究酯化工序的改造。酯化是DOP生产的关键工序,酯化釜是关键设备,把实验研究与计算机模拟研究相结合,先对间歇酯化工艺进行了实验研究,得到最优工艺参数和动力学参数,再对工厂生产装置进行标定,分析2种操作方式下得到的动力学参数,在此基础上进行酯化工序模拟分析,验证模型的可靠性后,设计出新的酯化釜,得到连续酯化最优的操作参数。改造后的酯化工序单耗下降,产量增加,产品质量稳定且有所提高。本研究可为DOP的新建或扩产改造提供有利参考。

Dioctyl phthalate（DOP） is used in substantial quantities in industry, primarily as a plasticiser for PVC and other polymers. Esterification is one of the key procedures of DOP production. The kinetics of the esterification of phthalic anhydride with 2-ethyl-hexanol using tetrabutyl titanate as catalyst have been investigated in an isothermal semihatch reactor. The kinetics parameters have been determined. The activation energy was found to be 101207 J/mol. The experiments have also been studied in continuous apparatus in factory to find the kinetics parameters and bottleneck of esterification. Based on the experimental results, the reactive distillation model were built to simulate the esterification process. Simulation results agreed well with experimental ones. The optimal process parameters were determined and new five subsidiary reactor were designed through simulation. Under these process parameters the final acid number of product is 0.21 mg/g, the conversion of phthalic anhydride is 99.78% and total residence time is 7 hours. The production capacity of the factoty has been increased from 50000 t/a to 100000 t/a with saving energy, decreasing the consumption of raw material and improving product quality. The study offers a significant solution for designing new equipment and reconstruction of DOP.