Refrigeration systems with a purge for removing non-condensables from the refrigerant and an acid filter for remove acid from the refrigerant are provided. The acid filter can be operatively connected to the purge. Optionally, the purge can include a separating device for separating non-condensable gases from condensable refrigerant gases and an acid filter is provided to remove acid from the condensable refrigerant gases.

Processes, systems, and associated control methodologies are disclosed that control the flow of biogas during the biogas cleanup process to create a more consistent flow of biogas through the digester, while also optimizing the output and efficiency of the overall renewable natural gas facility. In representative embodiments, a biogas buffer storage system may be used during the cleanup process to control the pressure and flow rate of biogas. The biogas buffer storage system may monitor and control the biogas flow rate to either bring down or increase the digester pressure, thereby maintaining a normalized biogas flow rate.

A method includes collecting exhaust gas comprising carbon dioxide (CO.sub.2) at a wellsite to provide a collected exhaust gas, separating CO.sub.2 from the collected exhaust gas to provide a separated CO.sub.2, and forming urea utilizing at least a portion of the separated CO.sub.2. A system for carrying out the method is also provided.

A fluid filter, filtering medium composition, and associated process for removing contaminants from feed and exhaust fluids used in fuel cell electricity generation, laboratories, the semiconductor and other industries to improve performance and extend useful equipment lifetimes and to clean fluids of sulfur compound contaminants, as well as to remove noxious NOx and halogen contaminants from feed and exhaust gases.

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.

A hydrocarbon adsorbent having a high hydrocarbon desorption start temperature and a method for adsorbing hydrocarbons that uses the hydrocarbon adsorbent are provided. The hydrocarbon adsorbent includes an alkali metal and a zeolite having a ring structure that includes at least 10 members is used. In the hydrocarbon adsorbent, a content of the alkali metal is 1 to 40 mass % based on a total mass of the hydrocarbon adsorbent, a content of the zeolite having a ring structure that includes at least 10 members is 99 to 60 mass % based on the total mass of the hydrocarbon adsorbent, and at least a portion of the alkali metal is in a state of being ion-exchangeable.

There is provided a gas trapping material and vacuum heat insulation equipment where the gas trapping material can be activated in a sealing step of the vacuum heat insulation equipment, and production efficiency can be enhanced by maintaining a high gas trapping characteristic even when a gas is released in a baking step or in a sealing step under an air atmosphere. The gas trapping material contains porous metal oxide and silver particles having an average particle size of 0.5 nm to 100 nm inclusive.

A cartridge mounting an air treatment material is a housing defining a housing in a perimeter. The air treatment material is received within the housing, and spaced from the inner wall of the housing by a plurality of resilient sheets. There is an inlet direction into the housing for air flowing across the air treatment material and an outlet opening on an opposed side of the housing. There are top and bottom surfaces and side surfaces forming a perimeter about the air treatment material. The resilient sheets extend substantially continuously across the side surfaces and the top and bottom surfaces at least at the inlet end to increase airflow across the air treatment material. An enclosed inhabited space is also disclosed and claimed.

An oxygen absorbent composition which comprises a polyester oligomer containing a constitutional unit derived from a tetralin ring-containing carboxylic acid and a diol, wherein the polyester oligomer has a number average molecular weight of 500 to 10000, and a transition metal catalyst comprising at least one transition metal selected from the group consisting of manganese, iron, cobalt, nickel and copper.