Disclosed are methods and systems for reducing elemental sulfur production in a gas production plant that includes receiving produced fluids high in hydrogen sulfide, removing hydrogen sulfide and converting hydrogen sulfide to elemental sulfur in a Claus unit. An acid gas stream is diverted from a feed line to the Claus unit in the gas processing plant and directed to a multistage acid gas compressor. An elemental sulfur production rate is reduced without reducing a production rate of the produced fluids. The compressed acid gas stream can be injected into a subterranean formation. In some embodiments, the gas production plant is integrated with an oil processing and gas injection plant.

A process for selectively separating H.sub.2S from a gas mixture which also comprises CO.sub.2is disclosed. A stream of the gas mixture is contacted with an absorbent solution comprising one or more amines, alkanolamines, hindered alkanolamines, capped alkanolamines, or mixtures thereof. The H.sub.2S/CO.sub.2 selectivity of the absorbent solution is preferably greater than about 4.0 for an acid gas loading [mol(CO.sub.2+H.sub.2S)/mol(amine)] between about 0.2 and about 0.6, and is achieved by reducing pH of the absorbent solution.

A method for recovering an acidic gas, includes: a step of bringing a gas to be treated that contains an acidic gas into gas-liquid into contact with an amine absorbing solution, allowing the amine absorbing solution to absorb the acidic gas, thereby removing the acidic gas from the gas to be treated; a step of allowing the amine absorbing solution that has absorbed the acidic gas to release the acidic gas, thereby regenerating the amine absorbing solution, and at the same time, recovering the released acidic gas; and an analysis step of calculating concentrations of iron ions and/or heavy metal ions in the amine absorbing solution.

Methods and systems for gas separation of syngas applying differences in water solubilities of syngas components, the method including producing a product gas comprising hydrogen and carbon dioxide from a hydrocarbon fuel source; separating hydrogen from the product gas to create a hydrogen product stream and a byproduct stream by solubilizing components in water that are more soluble in water than hydrogen; injecting the byproduct stream into a reservoir containing mafic rock; and allowing components of the byproduct stream to react in situ with components of the mafic rock to precipitate and store components of the byproduct stream in the reservoir.

Systems and methods for preventing formation of carbonyl sulfide in the production of sweet gas using an amine-lean aqueous solution and metal oxide adsorbent material. In embodiments, a method may include producing, via an amine absorption column supplied with a raw gas stream that includes fractions of hydrogen sulfide (H.sub.2S), carbon dioxide (CO.sub.2), and carbon monoxide (CO), (1) a sweet gas stream that includes the fractions of the CO and (2) an amine-rich aqueous solution that includes the H.sub.2S and CO.sub.2. The method may include heating the amine-rich aqueous solution to produce a heated amine-rich aqueous solution. The method may include producing, via an amine regenerator supplied with the heated amine-rich aqueous solution (1) an acid gas stream that includes the H.sub.2S and CO.sub.2 and (2) an amine-lean aqueous solution. The method may include producing, via adsorption in a metal oxide adsorbent vessel, an effluent stream that includes the CO.sub.2.

A process and apparatus for producing pure hydrogen from a syngas generated by the high temperature gasification of municipal, agricultural or industrial derived wastes. The process is able to make pure hydrogen to be further reacted with nitrogen to make ammonia and urea.

A system and method for processing unconditioned syngas first removes solids and semi-volatile organic compounds (SVOC), then removes volatile organic compounds (VOC), and then removes at least one sulfur containing compound from the syngas. Additional processing may be performed depending on such factors as the source of syngas being processed, the products, byproducts and intermediate products desired to be formed, captured or recycled and environmental considerations.

A process for selectively separating H.sub.2S from a gas mixture which also comprises CO.sub.2 is disclosed. A stream of the gas mixture is contacted with an absorbent solution comprising one or more amines, alkanolamines, hindered alkanolamines, capped alkanolamines, or mixtures thereof. The H.sub.2S/CO.sub.2 selectivity of the absorbent solution is preferably greater than about 4.0 for an acid gas loading [mol(CO.sub.2+H.sub.2S)/mol(amine)] between about 0.2 and about 0.6, and is achieved by reducing pH of the absorbent solution.

The absorption agent of the present invention contains water, an amine compound, and an organic solvent, and a value obtained by subtracting a solubility parameter of the organic solvent from a solubility parameter of the amine compound is 1.1 (cal/cm.sup.3).sup.1/2 or more and 4.2 (cal/cm.sup.3).sup.1/2 or less. The method for separation and recovery of an acidic compound of the present invention includes the steps of: bringing a mixed gas containing an acidic compound into contact with an absorption agent containing water, an amine compound, and an organic solvent to absorb the acidic compound into the absorption agent; causing the absorption agent that has absorbed the acidic compound to be phase-separated into a first phase containing the acidic compound in a high content and a second phase containing the acidic compound in a low content; and heating the first phase to release the acidic compound from the first phase.

Systems and methods for selectively removing hydrogen sulfide from a feed gas stream. The systems include an absorber-heat exchanger (ABHEX) assembly configured to exchange thermal energy between a mixed stream and a thermal management fluid stream. The ABHEX assembly defines a mixed stream volume and a thermal management fluid stream volume. The ABHEX assembly includes an isolation structure that maintains fluid separation between the mixed stream and the thermal management fluid stream and facilitates thermal communication between the mixed stream and the thermal management fluid stream. The ABHEX assembly is configured to receive and to mix the feed gas stream and a lean solvent stream to generate the mixed stream, to separate the mixed stream into a product gas stream and a rich solvent stream, and to cool the mixed stream. The methods include methods of operating the systems.