共沸法回收废稀释剂中PGMEA和PGME的研究

Recovery of PGMEA and PGME from Waste Diluent by Azeotropic Method

丙二醇甲醚醋酸酯(PGMEA)和丙二醇甲醚(PGME)的混合物是电子行业使用的一种优良稀释、清洗溶剂,稀释、清洗后产生含有PGMEA、PGME和水等物质的废稀释剂,PGMEA和PGME与水都会形成共沸物,采用普通精馏法难以得到较高的回收率。以环己烷为共沸剂,利用环己烷与水产生的共沸物沸点更低的特性,通过共沸精馏法回收废稀释剂中的PGMEA和PGME。应用流程模拟分析剂/水比、回流比等操作参数对原料脱水及产品回收率的影响,结果表明:共沸塔剂/水比为10∶1、PGME成品塔回流比为8、PGMEA成品塔回流比为0.45时,回收的PGME产品质量分数为99.01%,PGMEA产品质量分数为99.04%。与普通精馏回收工艺相比,共沸法的PGME产品回收率从40.57%提升至81.15%,PGMEA产品回收率从99.68%提升至99.90%,精馏系统吨产品的能耗从6.30MJ/t增加至7.76MJ/t。

The mixture of propylene glycol methyl ether acetate(PGMEA)and propylene glycol methyl ether(PGME)is an excellent diluent and cleaning solvent used in the electronics industry.After dilution and clean-ing,waste diluent containing PGMEA,PGME and water is produced.PGMEA and PGME will form azeotrope with water,and it is difficult to obtain a high recovery rate using ordinarydistillation method.Using cyclohex-ane as the azeotropic agent,PGMEA and PGME in waste diluent are recovered by azeotropic distillation with the lower boiling point of the azeotrope produced by cyclohexane and water.The effects of operating parame-ters such as agent/water ratio and reflux ratio on raw material dehydration and product recovery rate are an-alyzed by process simulation.The results show that when the agent/water ratio of azeotropic tower is 10:1,the reflux ratio of PGME tower is 8 and the reflux ratio of PGMEA tower is 0.45,the mass fraction of PGME product recovered is 99.01%and the mass fraction of PGMEA product recovered is 99.04%.Compared with the ordinarydistillation recoveryprocess,the azeotropicmethod increases the recovery rate of PGME product from 40.57%to 81.15%,increases the recovery rate of PGMEA product from 99.68%to 99.90%,and in-creases the energyconsumption per ton of product of the distillationsystem from 6.30MJ/t to 7.76MJ/t.