Can pervaporation separate methanol and water?
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I have read a lot of literature introducing the use of permeation membranes to separate ethanol and water. Can it also be used to separate methanol and water? Should I use a water-permeable membrane or an alcohol-permeable membrane?
In this regard, Dalian Precool Manufacturing Co., Ltd. is cooperating with Sinopec to carry out relevant scientific research work. For details, see: http://www.puricle.cn/chanpin/new.htm
There is no great selectivity between the preferentially water-permeable membrane and the preferentially alcohol-permeable membrane. The relative volatility of methanol-water is between 6-8. It should be known that the separation process using the principle of relative volatility is the distillation process, that is, the multi-stage multi-effect evaporation and condensation process. If a single-stage permeation distillation method (vaporization) wants to compete with distillation, the selectivity must be above 20 in any case.
Methanol and water can be separated according to membrane separation, but the economic aspects of membrane separation and distillation separation must be considered. Also, the product grade and precision you want methanol to reach should be specific and compared to the best.
It depends on the concentration of methanol and water. For low concentrations, it is of course better to use a membrane that preferentially permeates organic matter. For high concentrations, it is more economical to choose a water-permeable membrane.