COMBINED METHOD USING ADSORPTION AT VARIABLE PRESSURE AND MEMBRANES FOR EXTRACTION OF HELIUM Russian patent published in 2019 - IPC C01B23/00 B01D53/47 B01D53/22 

FIELD: chemistry.

SUBSTANCE: invention can be used for extraction of helium from natural gas or purging gases of production processes. To obtain helium from process gas, process gas is forced under pressure of less than 15 bar into pre-treatment unit where undesirable components are removed. Process gas is then fed to a first membrane separation stage, having a first membrane which is more easily permeable to helium than at least one other component contained in the process gas. First stream of retentate is sent to the second membrane separation stage, containing the second membrane, which is more easily permeable for helium, than at least for one other component contained in process gas. Helium is separated from the first stream of helium-containing permeate by adsorption at variable pressure to obtain a product stream containing helium. Recycling the second stream of helium-containing permeate to the first membrane separation stage, as well as recirculation of the purge gas after adsorption at variable pressure to the first membrane separation step. Second retentate flow not passed through second membrane is removed in form of exhaust gas.

EFFECT: invention enables to obtain high purity helium with high output.

7 cl, 1 dwg