Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

The present invention relates to an adsorption process for xenon recovery from a cryogenic liquid or gas stream wherein a bed of adsorbent is contacted with a xenon-containing liquid or gas stream selectively adsorbing the xenon from said 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. After the stripping step, the xenon adsorbent bed is drained to clear out the liquid residue left in the nonselective void space and the xenon molecules in those void spaces is recycled upstream to the ASU distillation column for increasing xenon recovery. The xenon adsorbent bed is optionally purged with oxygen, followed by purging with gaseous argon at cryogenic temperature (≤160 K) to displace the oxygen co-adsorbed on the AgX adsorbent due to higher selectivity of argon over oxygen on the AgX adsorbent. By the end of this step, the xenon adsorbent bed is filled with argon and xenon. Then the entire adsorbent bed is heated indirectly without utilizing any of the purge gas for direct heating. Operating the adsorption bed to near full breakthrough with xenon and displacing the adsorbed oxygen and other residues with argon, prior to regeneration, along with indirect heating of the bed, enables production of a high purity product ≥40 vol % xenon from the adsorption bed and further enables safely heating without any purge gas and ease for downstream product collection, even in cases where hydrocarbons are co-present in the feed stream.

Methods and systems for producing Xenon-133 are disclosed. A method for producing Xenon-133 includes collecting an off gas from a Molybdenum-99 production process in a storage tank. The off gas includes Xenon-133 and Krypton-85. The method further includes selectively adsorbing Xenon-133 from the off gas onto a charcoal column assembly such that Xenon-133 is selectively adsorbed onto the charcoal column assembly relative to Krypton-85. The method further includes desorbing the Xenon-133 from the charcoal column assembly by heating the charcoal column assembly, and condensing the Xenon-133 within a coil assembly.

Novel methods for pretreating a rare-gas-containing stream exiting an etch chamber followed by recovering the rare gas from the pre-treated, rare-gas containing stream are disclosed. More particularly, the invention relates to the pretreatment and recovery of a rare gas, such as xenon or krypton, from a nitrogen-based exhaust stream with specific gaseous impurities generated during an etch process that is performed as part of a semiconductor fabrication process.

Methods and systems for producing Xenon-133 are disclosed. A method for producing Xenon-133 includes collecting an off gas from a Molybdenum-99 production process in a storage tank. The off gas includes Xenon-133 and Krypton-85. The method further includes selectively adsorbing Xenon-133 from the off gas onto a charcoal column assembly such that Xenon-133 is selectively adsorbed onto the charcoal column assembly relative to Krypton-85. The method further includes desorbing the Xenon-133 from the charcoal column assembly by heating the charcoal column assembly, and condensing the Xenon-133 within a coil assembly.

A method for the extraction of xenon gas bound to a filter material using supercritical CO.sub.2 to form a mixture in which both CO.sub.2 and xenon are in a supercritical state.

Xenon is contained within articles of manufacture such as light bulbs. Described herein are an apparatus, system, a method to capture and collect the xenon contained in articles of manufacture such as defective light bulbs for recovery and/or reuse.

The present invention relates to an adsorption process for xenon recovery from a cryogenic liquid or gas stream wherein a bed of adsorbent is contacted with a xenon-containing liquid or gas stream selectively adsorbing the xenon from said 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. After the stripping step, the xenon adsorbent bed is drained to clear out the liquid residue left in the nonselective void space and the xenon molecules in those void spaces is recycled upstream to the ASU distillation column for increasing xenon recovery. The xenon adsorbent bed is optionally purged with oxygen, followed by purging with gaseous argon at cryogenic temperature (160 K) to displace the oxygen co-adsorbed on the AgX adsorbent due to higher selectivity of argon over oxygen on the AgX adsorbent. By the end of this step, the xenon adsorbent bed is filled with argon and xenon. Then the entire adsorbent bed is heated indirectly without utilizing any of the purge gas for direct heating. Operating the adsorption bed to near full breakthrough with xenon and displacing the adsorbed oxygen and other residues with argon, prior to regeneration, along with indirect heating of the bed, enables production of a high purity product 40 vol % xenon from the adsorption bed and further enables safely heating without any purge gas and ease for downstream product collection, even in cases where hydrocarbons are co-present in the feed stream.

A host material may be used for the separation of elements or compounds, wherein the host material is an organic molecular solid with suitable cavities for accommodating a guest material to be separated, and with interconnections between the cavities to allow the guest material to diffuse through the host material, and wherein said interconnections are closed for a proportion of the time or have a static pore limiting diameter which is smaller than the static dimension of the guest material. Applications include separations of rare gases, chiral molecules, and alkanes. One class of suitable host materials may be made by imine condensation.