Principle

Membranes separate gases by the principle of selective permeation across the membranes wall. For nitrogen polymeric membranes, the rate of permeation of each gas is determined by its solubility in the nitrogen membrane material, and the rate of diffusion through the molecular free volume in the nitrogen membrane wall. Gases that exhibit high solubility in the nitrogen membranes, and gases that are small in molecular size, permeate faster than larger, less soluble gases.

Fast" gases permeate through the nitrogen membrane wall more readily than "slow" gases, thus separating the original gas mixture into two streams. The purity of the desired streams can be adjusted by changing the operating conditions.

Process

Membrane processes rely on the fact that under pressure, gases tend to be permeated through the wall of the hollow fibre membranes. Faster gases permeate faster than slower gases. When a treated compressed air passed through the membrane, water, carbon dioxide and oxygen permeates and vented to atmosphere where as Nitrogen comes out in the main stream as the product gas.. It is a continuous process. No depressurization or regeneration is required