In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

A process for recovery of helium from one or more than one helium-containing off-gas streams comprises preconditioning off-gas through a multi-stage preconditioning device, cryogenically separating a helium-enriched gas fraction from the preconditioned off-gas received from the preconditioning device a cryogenic separation device, and purifying the helium-enriched gas fraction received from the cryogenic separation device using a purification device so as to obtain purified helium gas with a higher helium content than the helium-enriched gas.

A method of separation of predetermined gas from the mixture of gases or an atmosphere, wherein said method of separation of predetermined gas from a mixture of gases or an atmosphere comprises passing a mixture of gases or an atmosphere through the reinforced mass selective fluid bandpass filter (8). The reinforced mass selective fluid bandpass filter comprises the mass selective fluid bandpass filter element (9) permanently affixed to the sintered metal load bearing structure (14). The mass selective fluid bandpass filter element consists of quartz glass, of either natural or manmade origin. This method provides removing predetermined gas from the group consisting of: .sup.1H.sub.2, .sup.1H.sup.2H, .sup.2H.sub.2, .sup.1H.sup.3H, .sup.2H.sup.3H, .sup.3H.sub.2, .sup.1H.sub.2O, .sup.1H.sup.2HO, .sup.2H.sub.2O.sub., .sup.1H.sup.3HO, .sup.2H.sup.3HO, .sup.3H.sub.2O, O.sub.2, O.sub.3, .sup.12CO.sub.2, .sup.13CO.sub.2, .sup.14CO.sub.2, .sup.4 CO, N.sub.2, NO, NO.sub.2, NO.sub.x, SiO.sub.2, FeO, Fe.sub.2O.sub.3, SiF.sub.4, HF, NH.sub.3, SO.sub.2, SO.sub.3, H.sub.2SO.sub.4, H.sub.2S, .sup.35Cl.sub.2, .sup.37Cl.sub.2, F.sub.2, Al.sub.2O.sub.3, CaO, MnO, P.sub.2O.sub.5, phenols, volatile organic compounds, and peroxyacyl nitrates.

A method and system for purification of helium and CO.sub.2 from a stream containing at least Helium, CO2, nitrogen or methane uses a combination of cryogenic, membrane and adsorption technologies.

According to one embodiment, a gas recovering apparatus includes a casing and a tube. The casing is provided with an inlet through which a gas flows in, a first outlet for discharging a first gas containing a gas to be recovered of the gas, and a second outlet for discharging a second gas other than the first gas of the gas. The casing is evacuated via the first outlet. The tube is provided in the casing from the inlet to the second outlet, and has a high permeability to the first gas and a low permeability to the second gas.

The present invention relates to a cryogenic process to produce crude helium from pretreated natural gas. The pretreated natural gas is processed in two flash stages using the helium free process stream as a stripping agent, and a distillation column with the identified operating conditions and process scheme to ensure 100% helium recovery with reduced capital and operating cost for producing the crude helium. The integration of the cryogenic process with the already known purification system to produce pure helium is demonstrated to ensure high helium recovery in a hybrid process.

A method for recovering a helium product or intermediate product, wherein a first natural gas stream containing helium is supplied to a first natural gas processing unit and at least one second natural gas stream containing helium is supplied to at least one second natural gas processing unit, at least the first natural gas processing unit comprising helium recovery means via which the helium product is formed from at least a part of the first natural gas stream. At least temporarily a helium transfer from the at least one second natural gas stream to the first natural gas stream by means of a helium transfer arrangement comprising a membrane unit is performed before the first natural gas stream is provided to the first natural gas processing unit and before the at least one second natural gas stream is provided to the at least one second natural gas processing unit.

In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

What is disclosed is a mass selective fluid bandpass filter. This filter provides for selecting gas molecules of a specific mass from a gas sample containing molecules of two or more mass species. This filter provides a means of operation of a selecting a predetermined gas from a group of gases or an atmosphere. The mass selective fluid bandpass filter consists of quartz glass, of either natural or manmade origin. This provides method of removing a predetermined gas from the group consisting of: .sup.1H.sub.2, .sup.1H.sup.2H, .sup.2H.sub.2, .sup.1H.sup.3H, .sup.2H.sup.3H, .sup.3H.sub.2, .sup.1H.sub.2O, .sup.1H.sup.2HO, .sup.2H.sub.2O, .sup.1H.sup.3HO, .sup.2H.sup.3HO, .sup.3H.sub.2O, .sup.3He, .sup.4He, O.sub.2, O.sub.3, .sup.12CO.sub.2, .sup.13CO.sub.2, .sup.14CO.sub.2, CO, N.sub.2, NO, NO.sub.2, NO.sub.x, SiO.sub.2, FeO, Fe.sub.2O.sub.3, SiF.sub.4, HF, NH.sub.3, SO.sub.2, SO.sub.3, H.sub.2SO.sub.4, H.sub.2S, .sup.35Cl.sub.2, .sup.37Cl.sub.2, F.sub.2, Al.sub.2O.sub.3, CaO, MnO, P.sub.2O.sub.5, phenols, volatile organic compounds, and peroxyacyl nitrates.

A helium-containing stream is recovered from a natural gas feed using a membrane followed by multiple distillation steps. Refrigeration is provided by expanding a bottoms liquid with a higher nitrogen content than the feed, achieving a lower temperature in the process. The helium-enriched vapor is then purified and the helium-containing waste stream is recycled to maximize recovery and reduce the number of compressors needed. The helium-depleted natural gas stream can be returned at pressure for utilization or transportation.