Simulation on process of batch extractive distillation with mixed solvent

Development of traditional batch extractive distillation with single solvent is limited because the selectivity of single solvent usually conflicts with its solubility.A regular batch extractive distillation with mixed solvents can extend greatly batch extractive distillation technology because of Effect of Mixed Solvents.The process of a regular batch extractive distillation with mixed solvents was simulated by a constant molar holdup model,which was solved by two-point implicit method.In the same condition as simulation,cyclohexane-benzene azeotropic mixture was separated using N,N-dimethyl formamide(DMF) and dimethyl sulfoxide(DMSO) as binary mixed solvent.Experiment results agree well with simulation.And the effect of column holdup and feed location of mixed solvent on the separation process was investigated.The productive rate decreases with the increase of column holdup,and the amount of product has almost not an obvious change.In addition,feed location of mixed solvent has an important influence on separation of azeotropic mixture,which must be chosen correctly.