双塔变压间歇精馏分离三元双共沸体系的工艺模拟与优化

Simulation and optimization of double-column pressure-swing batch distillation process for separation of ternary mixtures with double azeotropes

提出多储罐双塔变压间歇精馏工艺用于分离丙酸甲酯-甲醇-水三元双共沸混合物,通过不同压力下的三元相图对工艺可行性进行了分析,基于每批次100 kmol的生产容量,提出了对应的控制结构以实现混合物的高效分离。以工艺的设备费用与操作费用为目标函数,采用多目标优化,确定了最优的高压塔操作压力。采用热集成技术进一步降低了工艺能耗,并计算了集成前后工艺的经济与环境性能。模拟结果表明,在相同的产品纯度和收率条件下,热集成后工艺的年度总费用与环境排放量分别降低了0.625%与4.688%。

A multi-tank double-column pressure-swing batch distillation process was proposed for separation of methyl propionate-methanol-water ternary mixtures with double azeotropes.The feasibility analysis was carried out using ternary phase diagram under different pressures.Based on the batch production capacity of 100 kmol,the corresponding control structure was proposed to achieve the efficient separation of the mixture.Taking equipment costs and operating costs of the process as objective functions,the optimum operation pressure of high-pressure column was determined by multi-objective optimization.The thermal integration technology is used to further reduce the energy consumption,and the economic and environmental performance of the process before and after integration was calculated.The simulation results show that under the conditions of same product purity and yield,the total annual cost and environmental emissions of the process are reduced by 0.625%and 4.688%,respectively.