A permanently porous vanadium(II)-containing metal-organic framework (MOF) with vanadium(II) centers and methods for synthesis of such MOF frameworks are provided. Methods for using such compounds to selectively react with N.sup.2 over CH.sub.4 are provided. In the synthetic methods, a vanadium source, such as VY.sub.2(tmeda).sub.2, where Y is a halogen and tmeda is N,N,N′,N′-tetramethylethane-1,2-diamine and a H.sub.2(ligand) are reacted in the presence of acid in a solvent at between 110° C. and 130° C. to form an intermediate product. The intermediate product is collected and washed with a washing agent, such as DMF and acetonitrile, and the vanadium(II) based MOF is activated by heating the washed intermediate product to at least 160° C. under dynamic vacuum.

Embodiments of the disclosure provide a method and system for sulfur recovery. A Claus tail gas stream is fed to a hydrogenation reactor to produce a hydrogenated gas stream. The hydrogenated gas stream is fed to a quench tower to produce a quenched gas stream. The quenched gas stream is fed to a first stage adsorption vessel of first stage adsorption unit to produce a first outlet gas stream. The first outlet gas stream is fed to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream. The first stage adsorption vessel is regenerated to produce a first byproduct gas stream. The second stage adsorption vessel is regenerated to produce a second outlet gas stream including hydrogen sulfide. Optionally, a portion of the second byproduct gas stream or nitrogen can be fed to the first stage adsorption vessel or the second stage adsorption vessel for regeneration. Optionally, a sales gas can be fed to the second stage adsorption vessel for regeneration. Optionally, vacuum can be applied to the first stage adsorption vessel or the second stage adsorption vessel for regeneration.

Gas concentrating systems and methods are provided. In one embodiment, a gas concentrating system and method is provided that includes component heat management. The heat management system can include, for example, one or more air cooling paths. The air cooling paths direct cooling air into and out of component spaces having heat-generating mechanisms. In other embodiments, the heat management system can also include component spaces that are insulated against the heat of heat-generating components. By cooling heat-generating components and insulating other components from heat, reduced wear and extended component life can be achieved. This reduces component failure and costly service to repair or replace failed or worn components. Also, gas concentrating systems and methods are provided for mounting system components with or without the use fasteners and in combination with or without component heat management.

To provide a new compound with pores finely tunable in size so as to take up a specific element and release the specific element taken up in the pores as necessary, a synthesis method of the new compound, and a separation and recovery agent. The new compound represented by the following molecular formula:

(NH.sub.4)[Ln(C.sub.2O.sub.4).sub.2(H.sub.2O)]

wherein Ln represents a lanthanide selected from Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.

A method for extending useful life of a sorbent for purifying a gas by sorption of an impurity is provided. The method generating a electrical discharge within the gas to obtain a spectral emission representative of a concentration of the impurity. The method also includes monitoring the concentration of the impurity according to the spectral emission. The method also includes lowering the concentration of the impurity by conversion of at least a portion of the impurity into a secondary impurity having a greater affinity to the sorbent than the impurity. The method also includes comparing the concentration of the impurity to a polluting concentration and managing the sorption of the gas onto the sorbent according to the comparison.

A process is provided for increasing the recovery of high-purity hydrogen from a steam cracking process in situations where byproduct methane yield is high relative to hydrogen. After a hydrocarbon gas stream is sent through a cold box and demethanizer, a small proportion of methane is sent through a pressure swing adsorption unit separately from a gas stream that contains hydrogen to increase high-purity hydrogen recovery by about 6%.

The present invention relates to an improved process and system for cold smoking of seafood and meat. The process is directed towards the reduction of distasteful gas compounds in aerosol smoke that cause unwanted gas odors and flavors in subsequently smoked foods. The method is further effective in preserving the freshness, wholesomeness, and appearance of smoked seafood and meat by retaining the desirable preservative aerosol components of the smoke. A superior smoke aroma and flavor can be imparted to seafood and meat, without the interference of distasteful gases odors. The process is further highly efficient, by incorporation of condensation filtering to regulate water, collect, and recycle smoke flavoring liquid condensates, thereby maximizing the value recovery from the smoking system.

A portable gas separator assembly utilizing carbon molecular sieve absorbents or elements to separate a compressed air stream to extract nitrogen and oxygen molecules. Components of the assembly include at least two charging towers so that one tower can be charged with compressed gas while the other of the at least two towers is purged.

The present invention discloses methods for extracting and recycling ammonia in MOCVD processes by FTrPSA. Through pretreatment, medium-shallow temperature PSA concentration, condensation and freezing, liquid ammonia vaporization, PSA ammonia extraction, and ammonia gas purification procedures, ammonia-containing exhaust gases from MOCVD processes are purified to meet the electronic-level ammonia gas standard required by the MOCVD processes, so as to implement recycling and reuse of the exhaust gases, where the ammonia gas yield is greater than or equal to 70-85%. The present invention solves the technical problem that atmospheric-pressure or low-pressure ammonia-containing exhaust gases in MOCVD processes cannot be returned to the MOCVD processes for use after being recycled, and fills the gap in green and circular economy development of the LED industry.