Systems and methods are provided for recovering helium from a feed comprising helium, carbon dioxide, and at least one intermediate component having a volatility between those of helium and carbon dioxide. In particular, processes of the present invention comprise separating the carbon dioxide and the components of intermediate volatility from the helium at a temperature greater than −82.7° C. to form a helium-rich product stream, wherein the concentration of at least one of the intermediate components in the helium-rich product stream is lower than its concentration in the feed stream, and wherein at least part of the separation is effected by contacting a vapor with a liquid.

Apparatus, methods and uses for separating gas mixtures of at least two different gases under magnetic field and employing a membrane are described.

The gas separation method is executed under a condition in which a partial pressure of a first gas (G1) in a feed gas that contains at least mutually different gases being the first gas (GI), a second gas (G2) and a third gas (G3) becomes less than or equal to the total pressure of a permeate-side space (S2) of a gas separation membrane (30). The gas separation method includes a step of causing flow of a sweep gas that contains at least the third gas (G3) into the permeate-side space (S2) of the gas separation membrane (30) while supplying a feed gas to a feed-side space (S1) of the gas separation membrane (30). The permeation rate of the first gas (G1) in the gas separation membrane (30) is greater than the permeation rate of the second gas (G2).

The gas separation method is executed under a condition in which a partial pressure of a first gas (G1) in a feed gas that contains at least mutually different gases being the first gas (G1) and a second gas (G2) becomes less than or equal to a total pressure of a permeate-side space (S2) of a gas separation membrane (30). The gas separation method includes a step of causing flow of a sweep gas that contains at least a third gas (G3) being a different gas from the first gas (G1) and the second gas (G2) into the permeate-side space (S2) of the gas separation membrane (30) while supplying a feed gas to a feed-side space (S1) of the gas separation membrane (30). The permeation rate of the first gas (G1) in the gas separation membrane (30) is greater than the permeation rate respectively of the second gas (G2) and the third gas (G3).

A method for preparing an adsorbent is disclosed that includes mixing an NaY zeolite, aqueous Al(OH).sub.3, and aqueous KOH, and then heating the resultant mixture for an allotted amount of time to achieve a composition comprising at least 90% single phase chabazite having an Si/Al ratio of 1.0 to 2.2.

An adsorbent having a composition comprising at least 90% chabazite where the chabazite is a single phase chabazite having an Si/Al ratio of 1.2 to 1.8, the chabazite includes a mixture of at least two types of cations, and each of the at least two types of cations are in a molar ratio relative to Al of at least 0.05.

A semi-porous composite membrane and a method of manufacturing the semi-porous composite membrane. The semi-porous composite membrane includes a base supporting substrate comprising α-Al.sub.2O.sub.3, an outer layer comprising silica, and an intermediate layer comprising crystalline fibers of boehmite, and at least one of a secondary metal oxide and a synthetic polymer, wherein the intermediate layer is disposed between the base supporting substrate and the outer layer. The crystalline fibers of boehmite are a length of 5-150 nm. The semi-porous composite membrane may be employed in membrane reactors.

A system comprising a pumping system configured to pump respective exhaust gases from each of a plurality of chemical etching process chambers and to combine the exhaust gases to provide a combined exhaust gas, and a noble gas recovery system configured to process the combined exhaust gas to remove one or more noble gases therefrom.

Sealed containers for radioactive material are presented herein. A sealed container forms an interior envelope for housing a radioactive material and prevents escape of the radioactive material into a surrounding environment. The sealed container provides a diffusion window for gaseous decay products to escape at a particular diffusion rate. In one example, an apparatus, comprises a container forming a sealed interior envelope for a radioactive material. The container has an aperture covered by a window material, and properties of the window material are selected to provide for diffusion of at least one gas produced by radioactive decay of the radioactive material.

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.