差压热耦合萃取精馏工艺分离甲基环己烷和甲苯的模拟研究

以苯酚为萃取剂,采用萃取精馏对甲基环己烷(MCH)-甲苯(MB)物系进行分离,比较了常规萃取精馏工艺流程和差压热耦合萃取精馏工艺流程;采用Aspen Plus化工流程模拟软件对萃取精馏工艺分离MCH-MB物系进行了模拟计算,考察了差压热耦合萃取精馏工艺中萃取剂进料位置、原料进料位置、萃取剂与原料的摩尔比(溶剂比)、回流比和压缩比等参数对MCH产品纯度及工艺能耗的影响。模拟得到差压热耦合萃取精馏塔优化的操作参数:萃取剂进料位置为第6块理论板,原料进料位置为第4块理论板,溶剂比为2.95,回流比为6,压缩比为12。模拟结果表明,差压热耦合萃取精馏工艺节能效果显著,比常规萃取精馏工艺可节能74.97%,得到MCH产品的含量可达99.54%(x)。

Simulation of Different Pressure Thermally Coupled Extractive Distillation for Methylcyclohexane and Toluene System

Two extractive distillation processes,namely conventional extractive distillation process and different pressure thermally coupled extractive distillation process,were employed for the separation of methylcyclohexane(MCH) and toluene(MB) system with phenol as the extractant,and simulated by Aspen Plus chemical process simulation software.Their separation effects and energy consumptions were compared.The influences of several important parameters on the different pressure thermally coupled extractive distillation process were investigated,including extractant feed position,feedstock feed position,mole ratio of extractant to feedstock(solvent ratio),reflux ratio and the compression ratio.The optimal operation parameters are as follows:extractant feed position 6th plate,feedstock feed position 4th plate,solvent ratio 2.95,reflux ratio 6 and compression ratio 12.The results show that,compared with the conventional extractive distillation process,the different pressure thermally coupled extractive distillation process can save energy 74.97% with the MCH mole purity of 99.54% in the products.