Combining extractive heterogeneous-azeotropic distillation and hydrophilic pervaporation for enhanced separation of non-ideal ternary mixtures

摘要

The separation of non-ideal mixtures using distillation can be an extremely complex process and there continues to be a need to further improve these techniques.A new method which combines extractive heterogeneous-azeotropic distillation(EHAD)and hydrophilic pervapora-tion(HPV)for the separation of non-ideal termary mixtures is demonstrated.This improved distillation method combines the benefits of heterogeneous-azeotropic and extractive distillations in one column but no added materials are needed as is usually the case with pervaporation.The separation of water-methanol-ethyl acetate and water-methanol-isopropyl acetate mixtures were investigated to demonstrate the accuracy of the combined EHAD/HPV technique.There is not currently an established treatment strategy for the separation of the second mixtures in the literature.These separation processes were rigorously modelled and optimized using a professional flowsheet.The objective functions were total cost and energy consumption and heat integration was also investigated.The verification of the process modelling was carried out using laboratory-scale measurements.Extractive heterogeneous-distillation combined with methanol dehydration was found to be more efficient than conventional distillation for the separation of these highly non-ideal mixtures.