中文摘要：

以苯-甲苯-二甲苯精馏的MESH方程组为基础,用proⅡ模拟软件模拟,考察苯-甲苯-二甲苯物系组成对节能率的影响,并找出产品纯度对连接流股流量变化的灵敏度,在L/V＇为1.5时,塔顶、塔中、塔釜产品均达到最佳条件,在保证L/V＇最优前提下,以年费用即操作费用与设备折旧费用之和最小为目标函数,调节回流比及理论板数,优化苯-甲苯-二甲苯分离工艺,得出最优设计方案。结果表明,经优化设计的苯-甲苯-二甲苯物系的热偶精馏工艺比最好的普通精馏工艺节约能耗近40%。

英文摘要：

Based on MESH equation set of benzene-toluene-xylene distillation,stimulation is carried out by proⅡsoftware to evaluate the effects of benzene-toluene-xylene composition on the energy efficiency and to find out the sensitivity of product purity to the changes of flow rate of cycle streams. When the value of L/V＇ is 1. 5,purities of products at column top,mid-column and column bottom are all at their best. The optimal design scheme is obtained through adjusting reflux ratio and theoretical plate number,and optimizing the separation process of benzene-toluenexylene by aiming at minimum of annual operation cost and equipment depreciation in the premise of optimal L/V＇. The results show that energy consumption of the optimized thermally coupled distillation process for benzene-toluene-xylene system is nearly 40% of that of common distillation process.