A method of obtaining helium from a process gas. The process gas is at a pressure less than 15 bar to a first membrane separation stage having a first membrane more readily permeable for helium than for at least one other component in the process gas. A first retentate stream is fed to a second membrane separation stage having a second membrane more readily permeable for helium than for at least one other component in the process gas. Helium is separated from a first helium-containing permeate stream using a pressure swing adsorption to obtain a helium-containing product stream. A second helium-containing permeate stream is recycled to the first membrane separation stage. A purge gas from the pressure swing adsorption is also recycled to the first membrane separation stage.

Provided is a novel exhaust gas processing device which allows processing target exhaust gas having a large flow volume to be handled with a small-capacity plasma generator, by preheating a high-temperature decomposable gas component of the processing target exhaust gas. An exhaust gas processing device 10 preheats processing target exhaust gas F in the presence of moisture with heat from at least either an electric heater 15 or a heat exchanger 17 and subsequently thermally decomposes the exhaust gas with an atmospheric pressure plasma P. A device main body 11 has a heating decomposition chamber T therein. A plasma generator 14 is of a non-transferred type and is installed at a top surface portion 11a of the device main body 11. A reactor 12 has a cylindrical shape and is installed within the device main body 11 such that an upper end opening 12i thereof is directed toward a plasma emission port 14f of the plasma generator 14. A moisture supply unit 18 is provided at an inlet side of the device main body 11. At least either the electric heater 15 or the heat exchanger 17 is disposed in a first space T1.

Provided is a novel exhaust gas processing device which allows processing target exhaust gas having a large flow volume to be handled with a small-capacity plasma generator, by preheating a high-temperature decomposable gas component of the processing target exhaust gas. An exhaust gas processing device 10 preheats processing target exhaust gas F in the presence of moisture with heat from at least either an electric heater 15 or a heat exchanger 17 and subsequently thermally decomposes the exhaust gas with an atmospheric pressure plasma P. A device main body 11 has a heating decomposition chamber T therein. A plasma generator 14 is of a non-transferred type and is installed at a top surface portion 11a of the device main body 11. A reactor 12 has a cylindrical shape and is installed within the device main body 11 such that an upper end opening 12i thereof is directed toward a plasma emission port 14f of the plasma generator 14. A moisture supply unit 18 is provided at an inlet side of the device main body 11. At least either the electric heater 15 or the heat exchanger 17 is disposed in a first space T1.

Disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting gas streams with a mixed metal oxy-hydroxide media comprising two or more metals selected from the group consisting of magnesium, chromium, manganese, iron, cobalt, zinc and copper. Also disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting the gas streams with a mixed metal oxy-hydroxide media comprising one or more metals selected from the group listed above plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

Disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting gas streams with a mixed metal oxy-hydroxide media comprising two or more metals selected from the group consisting of magnesium, chromium, manganese, iron, cobalt, zinc and copper. Also disclosed are processes for removing H.sub.2S from gas streams containing H.sub.2S, the processes comprise contacting the gas streams with a mixed metal oxy-hydroxide media comprising one or more metals selected from the group listed above plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

A gas conditioning unit for a surgical gas delivery device is disclosed, which includes a filter housing having an insufflation gas flow path for delivering insufflation gas to a body cavity and for facilitating pressure measurements from the body cavity, a pressurized gas flow path for delivering pressurized gas from a pump in the surgical gas delivery device to an internal nozzle in the filter housing that accelerates the pressurized gas and thereby generates a continuous pressure barrier that inhibits egress of insufflation gas from the body cavity, a vacuum return flow path for returning depressurized gas spent by the internal nozzle back to the pump under vacuum, an air entrainment flow path for drawing air into the body cavity to maintain a given pressure therein, and a smoke evacuation flow path for conveying smoke from the body cavity.

A desulfurization gas process includes water vapor, CO.sub.2 and SO.sub.x (x=2 and/or 3). In a treatment unit, the gas contacts a cooled alkaline aqueous solution having a temperature lower than an initial gas temperature, water and a carbonate of an alkali metal, to cool the gas, condense some water vapor and absorb SO.sub.x in the carbonate-containing solution, produce an SO.sub.x-depleted gas and an acidic aqueous solution including sulfate and/or sulfite ions. The SO.sub.x-depleted gas and a portion of the acidic aqueous solution can then be withdrawn from the treatment unit. Carbonate of the alkali metal can be added to remaining acidic aqueous solution to obtain a made-up alkaline aqueous solution. This solution can be cooled and reused as the cooled alkaline aqueous solution. An SO.sub.x absorbent solution includes a bleed stream from a CO.sub.2-capture process, sodium or potassium carbonate, and an acidic aqueous solution obtained from desulfurization.

A desulfurization gas process includes water vapor, CO.sub.2 and SO.sub.x (x=2 and/or 3). In a treatment unit, the gas contacts a cooled alkaline aqueous solution having a temperature lower than an initial gas temperature, water and a carbonate of an alkali metal, to cool the gas, condense some water vapor and absorb SO.sub.x in the carbonate-containing solution, produce an SO.sub.x-depleted gas and an acidic aqueous solution including sulfate and/or sulfite ions. The SO.sub.x-depleted gas and a portion of the acidic aqueous solution can then be withdrawn from the treatment unit. Carbonate of the alkali metal can be added to remaining acidic aqueous solution to obtain a made-up alkaline aqueous solution. This solution can be cooled and reused as the cooled alkaline aqueous solution. An SO.sub.x absorbent solution includes a bleed stream from a CO.sub.2-capture process, sodium or potassium carbonate, and an acidic aqueous solution obtained from desulfurization.

A method of fuel tank inerting includes separating process air into nitrogen-enriched air and oxygen-enriched air with an air separation membrane. A vacuum is applied to the air separation membrane to produce a pressure differential across the air separation membrane. The vacuum is manipulated to vary the pressure differential and vary purity of the nitrogen-enriched air.

A method of fuel tank inerting includes separating process air into nitrogen-enriched air and oxygen-enriched air with an air separation membrane. A vacuum is applied to the air separation membrane to produce a pressure differential across the air separation membrane. The vacuum is manipulated to vary the pressure differential and vary purity of the nitrogen-enriched air.