Separation of Isopropanol-Water by Continuous Extractive Distillation With Diglycol as Solvent

In this paper,the extractant is diglycol,continuous extractive distillation process for isopropanol-water azeotropic system is simulated and optimized by choosing UNIFAC as the physical property method of calculation us-ing Aspen Plus V7.3. The separation effect and heat duty of the number of theory stages,the mixture feed stage,the solvent feed stage,the reflux ratio and the mole ratio of extractant to mixture (solvent ratio) are investigated by using sensitivity analysis tool. The optimal condition for the extractive distillation is as follows: the number of theory stages is 27,the mixture feed stage is 20st,the solvent feed stage is 3rd,the reflux ratio is 1.8,and the solvent ratio is 1.7. Under the technological condition: The separation effect of isopropanol of extractive distillation is up to 99.94%,and the recovery rate of diglycol is up to 99.995%. The results are useful for the design and operation of continuous ex-tractive distillation process for isopropanol-water azeotropic system.