OBTAINING HELIUM FROM STREAM OF NATURAL GAS Russian patent published in 2020 - IPC F25J3/02 

FIELD: gas industry.

SUBSTANCE: invention relates to gas industry. Method of producing stream (27) of helium gas from initial gas stream (1) containing at least helium, methane and nitrogen involves the following steps: step a): introduction of initial gas stream (1) into nitrogen removal unit (6) with double distillation column, which contains high-pressure distillation column (5), low pressure distillation column (7) and condenser (8) connecting column (5) with high pressure column (7); step b): extracting at outlet of condenser (8) at least one portion (12) of mixture (11) obtained in upper part of high-pressure tower (5); step c): expanding said mixture obtained at step b) to an intermediate pressure of 8 to 20 bar absolute pressure; step d): separating mixture (14) obtained at step c), in first vessel (15) for separating phases into liquid phase (16) and helium-rich gaseous phase (17); step e): at least partial condensation of helium-rich gaseous phase (17) in heat exchanger (24); stage f): separation of flow (25) obtained at stage e), in second vessel (26) for separation of phases into liquid phase (28) and gas phase (27) containing more than 50 % by volume of helium.

EFFECT: technical result is simplified installation and reduced power consumption.

12 cl, 1 dwg