二乙氧基甲烷-乙醇-水体系萃取精馏溶剂的筛选

由于二乙氧基甲烷-乙醇-水体系形成共沸物且共沸点接近,不能用普通精馏的方法分离,本文提出采用萃取精馏分离法。从二乙氧基甲烷、乙醇、水与溶剂分子之间存在的诱导力、静电力、色散力及氢键出发,分析和对比十二类溶剂,提出选用多元醇、水、胺类、酮作为萃取精馏溶剂；通过汽液平衡釜测定有所选溶剂存在时,各组分问的相对挥发度,确定乙二醇为分离二乙氧基甲烷一乙醇的良好溶剂；而乙二醇加盐作为复合溶剂,可提高二乙氧基甲烷-乙醇的分离效果。

Selection of extractive distillation solvent for diethoxymethane-ethanol-water

The extractive distillation separation is proposed for diethoxymethane-ethanol-water system for there being a common boiling point and a close boiling temperature so it is difficult separated by usual distillation.In this paper extractive agents are classified into twelve types from the interactions between molecules,electrostatic force,dispersion force,hydrogen bond,et al.The effects of all kinds of extractive agents on separation of diethoxymethane-ethanol-water system are analyzed,and multi alcohol,water,amines and ketone are chosen as separation agents for said system.The relative volatilities between different compositions are determined in select- ed solvents by vapor-liquid equilibrium kettle and glycol is approved an appropriate extractive solvent for diethoxymethane-ethanol.The composite extractive solvent of glycol and acetate kalium can make the said process better.