二氯甲烷废溶剂回收的工艺研究

Research on Waste Dichloromethane Solvent Recovery Process

采用Aspen Plus软件对二氯甲烷废溶剂回收分离过程进行模拟研究,确定了萃取塔(T1)的理论塔板数、萃取剂水的用量、二氯甲烷精馏塔(T2)的进料塔板位置、回流比R及理论板数等。通过萃取和精馏分离提纯了二氯甲烷废溶剂中的二氯甲烷,在工艺参数:萃取塔(T1)的理论塔板数为8,萃取剂水与二氯甲烷废溶剂质量比为0.5,二氯甲烷精馏塔(T2)理论塔板数为20,实际塔板数取30为佳,二氯甲烷溶剂从16~18块塔板进料,侧线采出二氯甲烷,回流比R为1.5时,塔顶产品二氯甲烷的质量分数≥99.70%,水分≤0.15%。

Aspen Plus software was used to simulate the waste dichloromethane solvent recovery and separation process and to calculate the number of theoretical plates and the amount of extractant water of Extraction Column T1 as well as the location of feed plates,reflux ratio R,and the number of theoretical plates of Dichloromethane Rectification Column T2.Dichloromethane was recovered from waste dichloromethane solvent via extraction,rectification and separation,and optimum process parameters were identified as follows:the number of theoretical plates of Extraction Column T1 is 8,the mass ratio of extractant water to waste dichloromethane solvent is 0.5,the number of theoretical plates of Dichloromethane Rectification Column T2 is 20 with the number of actual plates being 30 preferably,dichloromethane is fed from No.16 to No.18 plates with dichloromethane being drawn out from side line,and the reflux ratio R is 1.5.Dichloromethane mass fraction in overhead product is≥99.70%,and water content is≤0.15%.