A method for recovering C2 components in a methane-containing industrial gas includes the steps of (1) cooling a compressed methane-containing industrial gas and performing gas-liquid separation; (2) absorbing C2 components in the gas phase by using an absorbent to obtain an absorption rich liquid; (3) returning the absorption rich liquid to the compression in step (1) or mixing the absorption rich liquid with the liquid phase obtained in step (1) to obtain a mixed liquid, and depressurizing the mixed liquid or the absorption rich liquid; (4) performing methane desorption on the depressurized stream to obtain a rich absorbent, or performing second gas-liquid separation on the depressurized stream, followed by methane desorption on the second liquid phase to obtain a rich absorbent; and (5) desorbing and separating the rich absorbent to obtain a lean absorbent and an enriched gas, and recycling and reusing the lean absorbent.

One variation of a method includes: conveying a mixture of air in a working fluid through a compressor to heat and pressurize the mixture to promote absorption of carbon dioxide into the working fluid; depositing the mixture in a high-pressure vessel configured to remove air from the mixture of carbon dioxide in the working fluid; conveying the mixture through a turbine to reduce pressure and promote desorption of carbon dioxide from the working fluid; depositing the mixture in a low-pressure vessel for removal of carbon dioxide; in response to a temperature of an interior environment falling below a target range, conveying the working fluid through a heating element configured to transfer heat from the working fluid into the interior environment; and, in response to the temperature exceeding the target range, conveying the working fluid through a cooling element configured to transfer heat from the working fluid into an exterior environment.

Disclosed in the present invention are a low energy consumption anhydrous CO.sub.2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH.sub.2—) and a tertiary amine (—N—), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO.sub.2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.

An apparatus includes an absorber having a first packing section, a second packing section and a third packing section. The first packing segment includes a first structured packing, having a first specific surface area SA1, the second packing segment includes a second structured packing, having a second specific surface area SA2, and the third packing segment includes a third structured packing, having a third specific surface area SA3 where SA1<SA2<SA3. The structured packing in the various packing segment may be periodically interrupted with one or more layers of random packing.

A contaminant removal system for removing a contaminant from an environment includes a gas separator, a scrubber-separator downstream of the gas separator, and a stripper-separator downstream of the scrubber-separator. The gas separator is configured to receive a cabin air stream from the environment and concentrate the contaminant from the cabin air stream to produce a concentrated cabin air stream. The cabin air stream includes the contaminant, and the concentrated cabin air stream has a higher concentration of the contaminant than the cabin air stream. The scrubber-separator is configured to absorb the contaminant from the concentrated cabin air stream into a liquid sorbent and discharge a clean air stream to the environment. The stripper-separator is configured to desorb the contaminant from the liquid sorbent into a contaminant stream.

The present system reduces the cost of carbon capture by reducing the over-temperature needed to strip CO.sub.2 from a liquid or fluid solution. The system includes structures that enhance the rate of CO.sub.2 bubble nucleation.

An electrochemical cell includes (a) an anode including a first liquid permeable carbon cloth carbon electrode and a first current collector, (b) a cathode including a second liquid permeable carbon cloth electrode and a second current collector, (c) a separator made from an insulating material, and (d) a current source applying an electrical current to said anode and said cathode.

A process for treatment of gas mixtures containing acid gas, for the removal of said acid gas from the gas mixtures. The process has (A) an absorption step performed on a gas mixture containing acid gas by means of a solvent system containing at least one liquid absorption solvent for removing from the gas mixture the acid gas contained therein and forming a lean gas mixture, from which at least part of the acid gas have been removed, and an enriched solvent containing the acid gas and (B) a regeneration step, in which the enriched solvent is subjected to a gas/liquid separation step by a flash process to be separated from the absorbed acid gas and to produce an acid gas flow and a regenerated solvent, which is recirculated to the absorption step. The solvent system contains at least one liquid absorption solvent selected from switchable ionic liquids.

Apparatus and methods for desulfurization and decarbonization of a process gas containing sulfur oxides and CO.sub.2. Ammonia may be used as a desulfurizing and decarbonizing agent. The gas may enter a desulfurization apparatus for desulfurization, and to produce an ammonium sulfate fertilizer. The desulfurized gas may enter a decarbonization apparatus to remove carbon dioxide in the gas, and to produce an ammonium bicarbonate fertilizer. The decarbonized gas may contain free ammonia. The decarbonized gas may be washed with a desulfurization circulating fluid and then with water. The washing fluid may be returned to the desulfurization apparatus for use as an absorbing agent for desulfurization. Acidic desulfurization circulating fluid may be used to wash ammonia, thereby achieving a high ammonia washing efficiency, and a low ammonia slip during the decarbonization process.

Techniques according to the present disclosure include capturing carbon dioxide from a dilute gas source with a CO.sub.2 capture solution to form a carbonate-rich capture solution; separating at least a portion of carbonate from the carbonate-rich capture solution; forming an electrodialysis (ED) feed solution; flowing a water stream and the ED feed solution to a bipolar membrane electrodialysis (BPMED) unit; applying an electric potential to the BPMED unit to form at least two ED product streams including a first ED product stream including a hydroxide; and flowing the first ED product stream to use in the capturing the carbon dioxide from the dilute gas source with the CO.sub.2 capture solution.