萃取精馏分离乙酸甲酯-甲醇共沸物的模拟

Simulation of Methyl Acetate-Methanol Azeotropic Mixture by Extractive Distillation

采用化工流程模拟软件Aspen Plus,以水为溶剂,运用剩余曲线图方法对乙酸甲酯-甲醇共沸物的萃取精馏过程进行分析与过程模拟。考察原料和溶剂进料位置、溶剂比、回流比及溶剂进料温度对分离效果的影响。模拟结果表明:在保证产品纯度和较低能耗前提下,优化工艺条件为萃取精馏塔理论塔板数50块,原料和溶剂进料位置分别为第32和第24块塔板,溶剂比和回流比分别为1.6和5.0,溶剂进料温度35℃。在此工艺条件下,产品乙酸甲酯纯度99.75%(质量分数)以上,回收率达99.81%,产品热负荷3.95GJ·t^(-1)。

An extractive distillation process with water as the extractant for separating methyl acetate-methanol azeotropic mixture was studied with residue curve maps（RCM）by using Aspen Plus process simulation software.The effects of major design parameters,such as feeding position and solvent feeding position,mass ratio of extractant and feed（solvent ratio）,reflux ratio and the solvent feeding temperature on the extractive distillation were investigated.Aimed at mass fraction of MeOAc in the products and minimal energy requirements,the most appropriate configuration was 50 theoretical stages,raw materials and solvent feeding position 32 nd and 24 th respectively,solvent ratio 1.6,reflux ratio（mass ratio）5.0and the solvent feeding temperature was 35 ℃.Under these optimized conditions,the mass fraction of MeOAc in the products was99.75%,recovery ratio was 99.81% and the thermal load for product reached 3.95GJ·t^-1.