加盐萃取精馏分离醋酸甲酯-甲醇二元恒沸物

Separation of Methyl Acetate-Methanol Azeotrope by Extractive Distillation with Salt

用改进的O thm er汽液平衡釜测定了0.101 3M Pa下醋酸甲酯-甲醇体系在萃取剂和盐存在下的相对挥发度,测定了全浓度范围的汽液平衡数据,并进行了加盐萃取精馏工艺的实验。结果表明,水作为萃取剂,加入醋酸钾,可提高醋酸甲酯-甲醇体系的相对挥发度,加盐萃取精馏比普通的萃取精馏有优势,当溶剂体积比为1∶1时,萃取精馏塔塔顶采出的醋酸甲酯的质量分数可达到99%以上,萃取剂回收率达98%,盐可以全部回收。

Modified Othmer recirculation still had been used to determining relative volatility of methyl acetate-methanol system. Isobaric vapor-liquid equilibrium (VLE) data of whole range concentration of methyl acetate-methanol mixture, under 0.1013 MPa, and in presence of water as extracting agent, with or without salt were measured. The relative volatility of the mixture at azeotropic composition could be greatly improved by adding water, especially by adding water with acetate potassium. When V(methyl acetate-methanol) : V(water + salt) = 1:1 more than 99% (mass fraction) methyl acetate could be obtained from extractive distillation tower top. This method was very effective for separating methyl acetate-methanol mixture.