Study On The Separation Technology Of Isopropyl Acetate-Methanol Solvent

Isopropyl acetate and methanol as a solvent widely used in the field of fine chemicals, the recycling process has been plagued corporate environmental issues. In this paper, a Shanghai Pigments enterprises discharge isopropyl acetate-methanol mixed solvent were separated recycling research, the liquid-liquid extraction, extractive distillation and rectification three technologies combined with common separation methods achieve isopropyl acetate esters and effective separation and purification of methanol, and to achieve the following technical specifications:purity of isopropyl acetate99.3%(wt); methanol purity99.5%(wt).Using water as the extraction agent, to obtain a suitable process conditions:mixed solvent extractant feed volume ratio of1.7:1(V/V), the extraction temperature of5℃, extraction tower packing height of150cm (3theoretical plates). In this condition, the oil obtained after extraction of isopropyl acetate phase purity of97.6%(wt), the yield was68.4%(wt), a methanol of0.4%(wt), a water of2.0%(wt). The oil phase was dehydrated over anhydrous sodium sulfate, the purity of isopropyl acetate can be increased to99.3%(wt), and the water was reduced to0.3%(wt).Using water as extractive and Aspen Plus, the optimum conditions are:the bubble point feed extractant feed ratio of the raw material was1:4.76(W/W), extractant concentration was80%(wt), a reflux ratio of5,15theoretical plates, feed location for7th trays and extractant feed location for2nd trays. The product purity of isopropyl acetate96.2%(wt), the yield was98.6%(wt), a methanol of0.1%(wt), a water of3.7%(wt), the product was dried over anhydrous sodium sulfate after the dehydration treatment, the purity of isopropyl acetate can be increased to99.6%(wt), the water was reduced to0.3%(wt).Using the ordinary distillation of methanol-water mixture for separation distillation with Aspen Plus, the obtained optimum conditions are:feed the bubble point, a reflux ratio of3,25theoretical plates, feed location for12th trays. Methanol in the product purity of99.5%(wt), the yield was97.6%(wt), isopropyl acetate of0.5%(wt), a water of0.06%(wt).Using the CUP-TOWER and Aspen Plus for liquid-liquid extraction columns, extractive distillation, methanol distillation and related equipment for design.