A process is presented to treat a process gas stream containing hydrogen sulfide using a reverse jet absorber with a liquid treatment solution containing a chelated metal catalyst. A treat gas substantially free of the hydrogen sulfide is separated from a spent liquid treatment solution containing elemental sulfur which can then be regenerated in an oxidation vessel where it is contacted with an oxygen containing gas to convert the spent liquid treatment solution to a regenerated liquid treatment solution that can be recycled for introduction into the reverse jet absorber.

An aqueous coating composition that includes a binder, pigment, and a formaldehyde scrubbing urea compound. When applied to a substrate, the coating composition absorbs formaldehyde and other air pollutants from passing air.

Process for producing biomethane from a biogas stream including methane, carbon dioxide and at least one impurity chosen from ammonia, volatile organic compounds, water, sulfur-based impurities (H.sub.2S) and siloxanes. A biogas stream is dried, the at least one impurity is at least partially removed by solidification and removal of the impurity. The methane and the carbon dioxide contained in the biogas obtained from the second step are separated so as to produce a biomethane stream and a CO.sub.2 stream.

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.

The present invention relates to a process suitable for reducing ammonia loss and odor from organic material to the atmosphere. The process comprises feeding air to a plasma generator to produce a concentration of 0.1-12% by volume of NOx in the air by direct nitrogen fixation. Cooled air containing NOx from the plasma generator is fed to an absorption system comprising at least two absorption loops, wherein a first absorption liquid is circulating in the first absorption loop and a second absorption liquid is circulating in the second absorption loop. The air containing NOx is absorbed into the first absorption liquid to form an acidic solution comprising nitrates and nitrites. Off gases containing NO from the first absorption loop is fed to the second absorption loop, and the off gases containing NO are absorbed into the second absorption liquid having a lower pH.

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.