COMPOSITE GAS SEPARATING MEMBRANE AND METHOD OF FABRICATING THIS MEMBRANE Russian patent published in 2009 - IPC B01D71/80 B01D71/32 B01D71/56 B01D71/68 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to membrane technology and can be implemented for separating and concentrating of gases, particularly for concentrating carbon dioxide gas from various gas mixtures in chemical, oil chemical and other branches of industry. The composite gas separating membrane consists of a porous padding and of a polymer working layer made out of fluoroplastic with applied layer out of dimethyldiphenylpolysiloxan-diphenylpolysilsesquioxane and with additional layer made out of mixture of sulpho-containing aromatic polyamide of general formula [-NH-SO₃Na)-Ar-Ar-(SO₃Na)-NH-CO-Ar-CO-]_n and polyethylenepolyamine taken at ratio (wt parts): 1.0:(0.15-0.2). The membrane is produced by preparing a forming solution with solving sulpho-containing polyamide in water at mass ratio 1:(18.8-198.8). Further water solution of ammonia is added at volume required for obtaining pH value of 10-11. It is mixed with polyethylenpolyamine at mass ratio 1:(0.15-0.2) and acetone is introduced on base of mass ratio 1:2 in relation to water. Further processes of forming and drying are performed.

EFFECT: invention facilitates increased selectivity for separating systems of gases carbon dioxide gas/nitrogen.

3 cl, 10 ex