Study On Methanol-water Multi-effect Distillation

Separation process for methanol-water is analyzed. The Relation between boil-up rate and heating power, relation between boil-up rate and the efficiency of total column and influence of reflux ratio on product purity was established. Because of the high energy consumption for conventional methanol-water separation process, Multi-effect distillation processes including two-tower,three-tower and four-tower were proposed. Simulations of multi-effect concurrent and countercurrent distillation were performed by ASPEN PLUS software which RADFRAC block and WILS-RK physical property set were used,and the optimum operating conditions were determined based on the minimum energy consume and the variables of the distillate. The pressure distributions of towers were determined. The optimum reflux ratios and feed stage of towers were determined by the sensitivity analysis module of ASPEN PLUS software. The results show, the energy consumption for separation of methanol-water by three-tower countercurrent is the lowest.