A multi-stage membrane system is provided to separate helium from a gas stream such as a natural gas stream. There are at least two permeate streams from a first membrane module. One of the permeate streams is compressed and sent to a second membrane module while one of the permeate streams bypasses the compressor. There are control means provided to determine the flow for these two permeate streams based on factors including the compressor capacity, the concentration of the target component in the combined permeate streams and the capacity of the second membrane module.

The present invention relates to a process for obtaining pure helium using a first membrane separation stage a second membrane separation stage and a third membrane separation stage. The first membrane separation stage is supplied with a first helium-containing feed mixture, the second membrane separation stage with a second helium-containing feed mixture and the third membrane separation stage with a third helium-containing feed mixture a first permeate and a first retentate are formed in the first membrane separation stage, a second permeate and a second retentate in the second membrane separation stage and a third permeate and a third retentate in the third membrane separation stage. The first feed mixture is formed using at least part of a helium-containing starting mixture. The second feed mixture is formed using at least part of the first permeate. The third feed mixture is formed using at least part of the second permeate. The third permeate is at least partly processed by pressure swing adsorption to obtain pure helium and a residual mixture at least some of the residual mixture is used in the formation of the second or third feed mixture.

Systems for recovering neon from used neon are provided. The systems can include a pretreatment component operatively coupled to receive used neon gas from a system for producing UV light using neon, and a capture component operatively coupled to the pretreatment component. Methods for recovering neon from used neon are also provided.

A mobile mining platform for operation on a lunar surface can excavate and deposit regolith into a mill. The mill can agitate at least a portion of the excavated regolith to release volatile gases from the portion of the excavated regolith, without heat being applied to the portion of the excavated regolith. A refinery can perform molecular separation of the released volatile gases. In some embodiments, pressure in the mill can be increased through introduction of a diluent gas into the mill, to improve the efficiency of pumping the released volatile gases from the mill to the refinery. In some embodiments, volatile liquids stored on the platform and/or generated by the refinery can be used to cool the released volatile gases prior to molecular separation of the released volatile gases. In some embodiments, the mill can separate and collect regolith material of different sizes for different uses.

An apparatus, system, and methods for polarizing nuclei of a noble gas are disclosed. The disclosed system may include a polarization apparatus configured to polarize a noble gas mixture including xenon-129. The disclosed system also may include separate volumes for (1) saturating the polarizable noble gas mixture with alkali metal vapor, (2) desaturating said noble gas mixture from its alkali metal vapor after polarization is completed, (3) intermediate storage of the resultant polarized noble gas mixture, and (4) transfer of said polarized noble gas mixture to a storage vessel (e.g., a delivery bag). The disclosed system further may include separate reservoirs for (1) the noble gas(es) to be polarized, (2) lightweight gas(es) to displace the noble gas(es), and (3) a heavy inert gas (e.g., such as natural xenon) to push the polarized noble gas(es) into a storage vessel.

An apparatus, system, and methods for polarizing nuclei of a noble gas are disclosed. The disclosed system may include a polarization apparatus configured to polarize a noble gas mixture including xenon-129. The disclosed system also may include separate volumes for (1) saturating the polarizable noble gas mixture with alkali metal vapor, (2) desaturating said noble gas mixture from its alkali metal vapor after polarization is completed, (3) intermediate storage of the resultant polarized noble gas mixture, and (4) transfer of said polarized noble gas mixture to a storage vessel (e.g., a delivery bag). The disclosed system further may include separate reservoirs for (1) the noble gas(es) to be polarized, (2) lightweight gas(es) to displace the noble gas(es), and (3) a heavy inert gas (e.g., such as natural xenon) to push the polarized noble gas(es) into a storage vessel.

An apparatus and a process to recover high purity helium from a low helium content feed stream are disclosed. The apparatus includes a first dual reflux pressure swing adsorption (DRPSA) unit and a second DRPSA unit, each unit comprising a high pressure adsorption column and a low pressure adsorption column configured in fluid communication with the high pressure adsorption column. The first DRPSA unit is arranged to receive and separate the feed stream into a first reflux product and a first heavy product and circulate the first reflux product and the first heavy product between the high and low pressure adsorption columns to produce an intermediate helium-enriched stream. The second DRPSA unit is arranged to receive and separate the intermediate helium-enriched stream into a second reflux product and a second heavy product and circulate the second reflux product and the second heavy product between the high and low pressure adsorption columns to produce a high purity helium stream and a waste stream containing helium. The waste stream from the second DRPSA unit is recycled to one of a plurality of locations in the first DRPSA unit to increase helium recovery in the high purity helium stream produced in the second DRPSA unit.

An adsorption process for xenon recovery from a cryogenic liquid or gas stream is described wherein a bed of adsorbent is contacted with the aforementioned xenon containing liquid or gas stream and adsorbs the xenon selectively from this fluid stream. The adsorption bed is operated to at least near full breakthrough with xenon to enable a deep rejection of other stream components, prior to regeneration using the temperature swing method. Operating the adsorption bed to near full breakthrough with xenon, prior to regeneration, enables production of a high purity product from the adsorption bed and further enables oxygen to be used safely as a purge gas, even in cases where hydrocarbons are co-present in the feed stream.

The invention relates to a gas purifier that removes moisture and oxygen from inert gases and reducing gases, for example, at sub-atmospheric pressures. The purifier can remove part per million levels of moisture in a gas stream to less than 100 parts per trillion by volume, and has a low pressure drop and a sharp breakthrough curve.

Disclosed herein are novel RHO zeolites useful as kinetically selective adsorbents for oxygen and/or nitrogen. The adsorbents can be used in pressure swing adsorption processes for selectively adsorbing oxygen and/or nitrogen from feed streams such as an air stream or crude argon stream. Also disclosed are novel methods of preparing RHO zeolites, including in particular mixed-cation RHO zeolites.