以工业尾气为原料经二甲醚羰基化制备的醋酸甲酯料液,连续通过脱轻塔、精密精馏塔、脱重塔进行分离精制。采用化工模拟软件对该工艺模拟优化计算,脱轻塔塔顶脱轻组分,侧线采出质量分数99.9%以上的二甲醚,并将二甲醚中烯烃杂质质量分数控制在14×10^-6以下,以免循环回羰基化反应工段造成催化剂失活;精密精馏塔塔顶同时脱除和醋酸甲酯共沸的水、丙酮、甲醇杂质,脱重塔塔顶采出质量分数99.9%以上的醋酸甲酯产品,将工业尾气变废为宝,产生巨大经济效益。

A separation and refining process is proposed for methyl acetate feed solution that is prepared by dimethyl ether carbonylation with industrial off-gas as raw material.In the process,the feed solution is refined by continuously passing through light components removal column,precision distillation column,and heavy components removal column.The process is simulated and optimized by means of chemical process simulation software.Light-components in feed solution are removed on the top of light components removal column,and dimethyl ether with a purity of 99.9% or higher is extracted from the side of the column.Olefin impurities in dimethyl ether are below 14 ppm,which can avoid catalyst deactivation caused by olefin circulation back to the reaction section.Water,acetone,methanol that azeotrope with methyl acetate are removed on the top of precision distillation column.Methyl acetate product with a mass fraction of more than 99.9% is obtained from the top of the heavy components removal column.This process turns off-gas into valuables and gets great economic benefits.