The present invention relates to a novel phase transfer solvent composition for enhanced CO.sub.2 and/or H.sub.2S capture from flue gas and biogas having various gaseous compositions. Further, the present invention provides a process of preparing the phase transfer solvent composition of the present invention.

Methods and systems for converting ammonium waste streams into certifiably Organic ammonium salts having a variety of uses in greenhouse gas-reducing activities are herein described. The resulting ammonium salt compositions can be used to enhance crop yield.

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.

The invention is directed to a process to convert a sulphur compound to bisulphide by direct or indirect transfer of electrons from a cathode of a bio-electrochemical cell to the sulphur compound under anaerobic conditions and in the presence of mixed culture comprising methanogens and suitably also a anaerobic or facultative anaerobic bacteria. The sulphur compound may be a thiol like methanethiol or ethanethiol or a polysulphide, like dimethyl disulphide.

A composite amine absorbent according to the present invention is an absorbent for absorbing CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S in a gas. The absorbent is obtained by dissolving (1) a linear monoamine, (2) a diamine, and (3) propylene glycol alkyl ether, for example, represented by the following chemical formula (I) in water. In the composite amine absorbent, the components complexly interact, and the synergistic effect thereof provides good absorbability of CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S and good releasability of CO.sub.2 or H.sub.2S absorbed during regeneration of the absorbent. Furthermore, the amount of water vapor in a reboiler 26 used during regeneration of the absorbent in a CO.sub.2 recovery unit 12 can be reduced.

R.sup.1—O—(R.sup.2—O).sub.n—R.sup.3  (I)

In one embodiment, an acid gas removing apparatus includes an absorber configured to bring a first gas including an acid gas and a lean solution into contact to discharge a rich solution that is the lean solution having absorbed the acid gas, a regenerator configured to separate the acid gas from the rich solution discharged by the absorber to discharge the lean solution that is the rich solution separated from the acid gas, and a measuring instrument configured to measure a temperature of the rich or lean solution in the regenerator. Furthermore, an acid gas removal control apparatus that controls the acid gas removing apparatus includes a receiver configured to receive the measured temperature, and a controller configured to control resupply of a resupplied solution to the rich or lean solution or removal of an acid component from the rich or lean solution, based on the received temperature.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

A system and method for simultaneously removing water and acid gases from methane in a single process without requiring dehydration prior to acid gas removal. A feed stream comprising these components and little or no hydrocarbons heavier than methane is separated in a series of separators, including an absorber column using methanol as an absorber. A treated methane stream comprising at least 90%, more preferably at least 95%, most preferably at least 99%, of the methane from the feed stream and an acid gas waste stream comprising less than 10%, more preferably less than 5%, most preferably less than 1%, of the methane from the feed stream are produced. Using methanol as a physical solvent allows removal of water and acids gases in a single step using substantially less energy than conventional separation methods. The system and method are particularly useful in treating landfill gas feed streams.

The embodiment provides a composite that allows the release of acid gas, even the continuous release of acid gas, at low temperature and with a high acid-gas release rate in a regeneration tower of an acid gas removal apparatus, and a regenerator and an acid gas removal apparatus, in both of which the composite is used, and a method of acid gas removal. The composite according to the embodiment is capable of separating an acid gas from an acid gas absorbent, which has absorbed the acid gas, to regenerate the acid gas absorbent, wherein the composite contains an inorganic layered compound and an aluminum-containing oxide. Also provided are a regenerator using the composite to regenerate an acid gas absorbent that has absorbed an acid gas by allowing the acid gas absorbent to release the acid gas, and an acid gas removal apparatus equipped with the regenerator.

Methods and systems for treating an olefin-containing stream are disclosed. The disclosed methods and systems are particularly suitable for treating an off-gas stream in a refining or petrochemical process, such as from a fluid catalytic cracker (FCC), coker, steam cracker, and the like. The stream is treated in an absorber column to reject lighter stream components and to absorb ethylene and/or propylene into a solvent. The solvent is typically isobutane. The enriched solvent stream from the absorber column is fed to an alkylation reactor, which reacts the dissolved olefin with the isobutane solvent to produce an alkylate product.