Characteristics Of Pervaporation And Distillation
Naturally, PV display the following characteristics:
1. PV can also be used for the removal of certain components in equilibrium reactions.
2. Polymer membrane compaction, a frequent problem in high-pressure gas separation, is not encountered in pervaporation because the feed pressure is typically low.
3. The permeate pressure has to be always lower than the saturation pressure of the permeant to achieve separation.
4. Desorption of the component at the permeate side of the membrane. 
2.3 Operating Principles of distillation:
The basic principle of distillation is to bring a liquid into close contact with vapour so that the mass transfer between the two current phases can take place. The goal of each system to reach a state of equilibrium is based on the driving force for the mass transfer.
When the vapour pressure matches the surrounding pressure that’s when a liquid begins to boil. The principle on which a liquid boils depends on its volatility. Liquids with high vapour pressures will boil at lower temperatures. Distillation is accomplished because of the differences in the volatility of the components in a liquid