完全热集成变压精馏分离正丁醇和氯苯的模拟

Simulation of separation of n-butanol and chlorobenzene by fully heat-integrated pressure swing distillation

根据正丁醇-氯苯在不同压力下共沸组成变化较大的特点,采用变压精馏对正丁醇-氯苯共沸体系进行高纯度分离。利用化工流程模拟软件对变压精馏流程进行稳态优化模拟计算,以NRTL方程作为物性计算模型,以再沸器总热负荷最低为优化目标,对理论板数、进料位置和回流比等参数进行优化,得到变压精馏分离正丁醇-氯苯体系最佳操作参数。采用完全热集成变压精馏工艺进行节能,即利用高压塔塔顶气相潜热作为常压塔再沸器热源。模拟结果表明,利用完全热集成变压精馏冷凝器和再沸器热负荷分别节能38.88%和35.38%,同时可得到99.96%(w)的正丁醇和99.98%(w)的氯苯产品。完全热集成变压精馏是一种高效节能的分离正丁醇和氯苯共沸物的方法。

According to the great change of azeotropic composition of n-butanol and chlorobenzene at different pressures,a high purity separation of n-butanol and chlorobenzene azeotropic system was carried out by pressure swing distillation.The chemical process simulation software was used to simulate the steady-state optimization of the pressure swing distillation process.The NRTL equation was used as the physical property calculation model,and the minimum total heat load of the reboiler was optimized.The optimum operating parameters of the n-butanol-chlorobenzene system for pressure swing distillation were obtained by optimizing the theoretical plate number,feeding location and mass reflux ratio.The fully heat-integrated pressure swing distillation was used for energy saving,with the latent heat of the gas phase of the condenser of pressurized distillation column used as the heat source of the atmospheric reboiler.The simulation results showed that the fully heat-integrated pressure swing distillation was 38.88%and 35.38%more energy saving than that of the conventional pressure swing distillation of condenser and reboiler.At the same time,the product with 99.96%(w)of n-butanol and 99.98%(w)of chlorobenzene could be obtained.Fully heat-integrated pressure swing distillation was a highly efficient and energy saving method for separating n-butanol and chlorobenzene azeotrope.