Removal and Recovery of Organic Solvents from Aqueous Waste Mixtures by Extractive and Pressure Swing Distillation

Different scenarios for handling wastewaters of different concentrations containing acetone and methanol (in equimolar quantities) in order to remove and/or recover organic components are investigated by rigorous simulation. The extractive and pressure swing distillation processes are optimized by genetic algorithm (GA). The different alternatives including incineration of the whole amount of waste are compared on the basis of the capital, operation, and total annual costs. The influence of the water content of the waste mixture is also investigated. The best results are obtained with the separation of the whole quantity of the waste mixture into specified purity products by extractive distillation. The results obtained for pressure swing distillation with heat integration remained only slightly under those of the extractive distillation.