General Aspects Of Membrane Process:

Before we discuss the different types of processes, it will be necessary to get a clear picture of a simple membrane process and be familiar with the general terms in usage. It might be equally significant to know the criteria which evaluate the procedure under consideration.

A generalized and simplified schematic of membrane separation process is given in Figure.

Figure:  A schematic representation of a simple membrane process

In membrane separation procedures, two bulk phases are separated through a barrier which is known the membrane. A membrane controls the passage of various chemical substances by it that depends upon the nature of the chemical substances and the membrane. This concludes within depletion of that substance in the permeate by the membrane.

The membrane phase could either be nonporous, microporous, mesoporous or macroporous. Through IUPAC classification, pores among 20 Å   and 500 Å   are known as mesoporous and pores larger than 500 Å are called macropores. A membrane could also either be a solid or a liquid. It could be a polymeric material, inorganic refractory compound or a metal or their composites.