What is pervaporation method for separation?






The separation process of the pervaporation method can be broadly divided into two stages: liquid permeation and evaporation. Therefore, it is also called the permeation vaporization method.

This is a separation method that has been attracting attention in recent years, replacing the distillation method. The inner side of the silicone membrane module is in contact with a liquid containing the target substance to be separated, while the outer side is vacuumed, or gas is supplied to vaporize and permeate the liquid.

It is a membrane separation technology mainly used to collect solvents in organic solvents because it can separate and concentrate mixed components at the molecular level by using a pore-free polymer membrane or a porous membrane with ultra-fine pores.

The selectivity of the membrane increases the vapor concentration of the target material on the permeate side, which can then be cooled, condensed, and recovered as a concentrated liquid.

For example, let’s see how to use silicone membrane to turn 10% ethanol solution into a 60% one.

When a 10% low-concentration ethanol solution is passed through the membrane, ethanol (vapor) preferentially permeates the membrane, and a 60% ethanol solution can be acquired and concentrated on the permeation side.

This separation method has significant advantages over other separation methods because it does not require large facilities like distillation methods and can effectively separate azeotropic mixtures.