醋酸-对二甲苯-水体系共沸精馏的模拟分析

Simulation analysis on azeotropic distillation of acetic acid-p-xylene-water system

采用Aspen Plus11.1化工流程模拟软件,对扬子石油化工有限公司化工厂精对苯二甲酸(PTA)装置的溶剂脱水塔生产过程进行了模拟计算,采用NRTL-HOC热力学计算模型,并进行热力学参数修正,通过调整塔板数、热负荷、进料位置、操作压力、对二甲苯(PX)采出位置等操作参数,得出各塔的最佳工艺条件。在最佳工艺条件下,分析了此分离过程的能耗问题。模拟结果表明,溶剂脱水塔分离得到的醋酸、水、PX均能达到产品质量要求,工艺流程合理、可靠。

The design and optimization are carried out for the separation process of solvent dehydration column in PTA plant by the chemical simulation software of Aspen 11.1 model. Nonrandom two liquids hayden-O＇connell（ NRTL- HOC） thermodynamic calculation model is used and some what thermodynamics parameters are modified. However, theoretical plate number,heat duty,feed location,operation pressure and discharging plate of p-xylene are adjusted in order to obtain optimal results for azeotropic distillation. Under the optimum conditions, the energy consumption in the distillation is analyzed. The results demonstrate that the acetic acid,p-xylene and water from the separation process of solvent dehydration column can meet with the quality requirement. The process is reasonable and reliable, and has some reference significance for engineering and operation.