Membrane separation technology

Membrane separation and recovery technology is a technology that realizes gas separation according to the dissolution and diffusion of gas molecules through the membrane wall under the action of partial pressure difference. It is widely used in the recovery of H2 from the purge gas of synthetic ammonia in synthetic ammonia plants; H2/CO ratio adjustment in petrochemical industry and H2 recovery from methanol purge gas; H2 concentration in tail gas of refinery hydrogenation unit; H2 recovery from recycle tail gas of hydrogenation unit, hydrogen purification of catalytic reforming gas, etc.

Technical principle:

1. The gas passes through the membrane wall under the action of differential pressure

2. The principle of gas compound interaction of permeability. The mechanism of gas permeability is the interaction of dissolution and diffusion

3. Gas permeability coefficient is generally expressed in P/I

4. Selectivity is related to the P/I value of each gas component and is defined as "alpha"

5. When the P/I values of the two gases differ greatly, the gas will be separated

Permeability relationship of each gas