完全热集成变压精馏分离异丙醇-二异丙醚共沸物的优化设计与控制

Optimization design and control of separation of isopropanol-diisopropyl ether azeotrope by fully heat integrated pressure swing distillation

高纯度异丙醇被广泛用作电子清洁剂与溶剂。异丙醇生产中,异丙醇与副产物二异丙醚形成共沸物,普通精馏无法有效分离,可采用完全热集成变压精馏工艺进行分离。利用Aspen Plus流程模拟软件,首先以高压塔再沸器热负荷最低为目标,对工艺进行局部优化;然后以年度总费用(TAC)最低为目标,采用序贯迭代法,对工艺进行全局优化。结果表明,优化设计极大地节约了能量,年度总费用降至416567 USD/a、高压塔塔板数减少为21块、设备费用降至536094 USD、完全热集成负荷达到751.71 kW。利用Aspen Plus Dynamics软件,采用压力补偿控温策略与组成-温度串级控制,建立了动态控制结构,在进料流量与进料组成发生±20%扰动时,仍表现出较好控制效果。

High purity isopropanol is widely used as electronic cleaner and solvent.In the production of isopropanol,it forms an azeotrope with the by-product diisopropyl ether,which cannot be effectively separated by ordinary distillation,so the fully heat integrated pressure swing distillation process can be used to separate the azeotrope.By using Aspen Plus process simulation software,the local optimization of the process was first carried out with the goal of minimizing the duty of the high-pressure tower reboiler.Then,with the goal of minimizing the total annual cost(TAC),the sequential iterative algorithm was used to optimize the process globally.The results show that the optimization design has greatly saved energy,with the total annual cost reduces to 416567 USD/a,the number of high pressure tower plates reduces to 21,the equipment cost reduces to 536094 USD,and the fully heat integrated duty reaches 751.71 kW.By using Aspen Plus Dynamics software and adopting pressure compensation temperature control strategy and composition temperature cascade control,a dynamic control structure was established.When the feed flow and feed composition are disturbed by±20%,the control effect is still good.