Systems and methods use bimetallic alloy particles for converting hydrogen sulfide (H.sub.2S) to hydrogen (H.sub.2) and sulfur (S), typically during multiple operations. In a first operation, metal alloy composite particles can be converted to a composite metal sulfide. In a second operation, composite metal sulfide from the first operation can be regenerated back to the metal alloy composite particle using an inert gas stream. Pure, or substantially pure, sulfur can also be generated during the second operation.

A separation membrane complex includes a porous support and a separation membrane formed on the support. The separation membrane has a small void. A small void index I.sub.k expressed by (Σ(S.sub.k.sup.1.5))/(S.sub.m.sup.1.5) and indicating the abundance ratio of small voids is higher than or equal to 10×10.sup.−15, and a large void index I.sub.p expressed by (Σ(S.sub.p.sup.2))/(S.sub.m.sup.2) and indicating the abundance ratio of large voids is lower than 200×10.sup.−22, where S.sub.m is the surface area of the separation membrane, S.sub.k is the area per small void, and S.sub.p is the area per large void. Accordingly, the separation membrane complex can achieve a high separation ratio.

A membrane including a polymer substrate having pore channels and a metal-organic framework disposed on the polymer substrate. Methods of producing the membrane are described. Methods of separating gases using the membrane are also provided.

A portable pressure swing adsorption method and system for fuel gas conditioning. A fuel gas conditioning system includes a pressure swing adsorption (PSA) system fluidly coupled to a rich gas stream, the PSA system including a plurality of adsorbent beds and configured to condition the rich natural gas stream and produce therefrom a high-quality fuel gas and gaseous separated heavier hydrocarbons, a product end of the adsorbent beds fluidly coupled to a fuel gas line, wherein the high-quality fuel gas is discharged from the product end and supplied to the fuel gas line, and a feed end of the adsorbent beds configured to be fluidly coupled to the rich natural gas stream or a raw natural gas stream, wherein the produced gaseous separated heavier hydrocarbons are recirculated into the rich natural gas stream or the raw natural gas stream.

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.

The invention relates to a process (100) for producing liquefied natural gas using a feedstock mixture that contains at least methane, one or more components boiling at a temperature lower than methane and one or more hydrocarbons boiling at a temperature higher than methane, wherein the hydrocarbon(s) boiling at a temperature higher than methane comprise one or more hydrocarbons freezing at a higher temperature, with a freezing point higher than −50° C. According to the invention the feedstock mixture is fed into a pressure swing adsorption process (10), in which a first fraction containing methane and a second fraction containing methane are formed, the first fraction containing methane contains, in addition to the methane, at least the predominant portion of the components of the feedstock mixture that boil more readily than methane and is low in or free from the hydrocarbons boiling less readily than methane, and the second fraction containing methane contains, in addition to the methane, at least the predominant portion of the hydrocarbons from the feedstock that boil less readily than methane and is low in or free from the components that boil more readily than methane, and the first fraction containing methane, or a portion thereof, is supplied for liquefaction (20). The invention also relates to a corresponding plant.

An aminated siliceous adsorbent, which is the reaction product of dried acidified rice husk ash having disordered mesopores and an amino silane, wherein amine functional groups are present on an external surface and within the mesopores of the dried acidified rice husk ash, and wherein the aminated siliceous adsorbent has a carbon content of 24 to 30 wt. %, based on a total weight of the aminated siliceous adsorbent. A method of making the aminated siliceous adsorbent and a method of capturing CO.sub.2 from a gas mixture with the aminated siliceous adsorbent.

A method for carbon dioxide recycle stream processing with ethylene glycol dehydrating in an enhanced oil recovery process includes receiving a first carbon dioxide recycle stream from a hydrocarbon formation, adding ethylene glycol to the first carbon dioxide recycle stream to produce an ethylene glycol and carbon dioxide recycle stream, condensing the ethylene glycol and carbon dioxide stream to produce a multiphase stream, separating the multiphase stream into a water and ethylene glycol stream and a second carbon dioxide recycle stream, separating the water and ethylene glycol stream into a water stream and an ethylene glycol stream, and separating the second carbon dioxide recycle steam into a carbon dioxide reinjection stream and a natural gas liquids stream.

A system and method for cooling, purifying and liquifying a feed gas stream uses liquid nitrogen for cooling the system. After cooling the system, the warmed nitrogen is vented as a vapor. The system and method include a water condenser, a first and second cooler and a liquifier and production of at least first and second contaminant streams. Optionally, the system includes a compressor or blower and/or a separator.

A high selectivity and high CO.sub.2 plasticization resistant polymer comprises a plurality of repeating units of formula (I) for gas separation applications. The polymer may be synthesized from a superacid catalyzed poly(hydroalkylation) reaction.

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Membranes made from the polymer and gas separation processes using the membranes made from the polymer are also described.