A method and apparatus for continuously treating acid gases including recovering absorbent chemicals by introducing streams leaving a regenerator and/or leaving an absorber into a static mixing zone wherein supplemental washing water is added to recover absorbent chemicals. Improvements to the prior art methods are provided where one or more absorbent chemical recovery units are included to increase the amount of recovered absorbent chemicals exiting the regenerator and/or exiting the absorber are increased and/or maximized. Absorbent chemical recovery units can include mixing units where liquid is added to the stream of sour gas and absorbent chemical to mix with and absorb the absorbent chemical from the stream.

Provided is a composition for removal of a sulfur-containing compound in a liquid or gas, wherein the sulfur-containing compound is at least one selected from the group consisting of hydrogen sulfide and a compound containing an —SH group, and the composition contains an aldehyde and a polyvalent amine represented by the general formula (1).

The acid gas removal system for removing acidic gases from gaseous hydrocarbons (10) removes sour gases, such as hydrogen sulfide (H.sub.2S) and carbon dioxide (CO.sub.2), from an input gaseous stream. The system (10) includes a contactor (12) for contacting the input gaseous stream with an absorption liquid solvent (ALS), and a stripper (24) for recycling the absorption liquid solvent (ALS) and removing acidic gases (AG) therefrom, but with the addition of a pair of plate-plate heat exchangers (22, 26). The first heat exchanger (22) heats the used absorption liquid solvent (UALS) output from the contactor (12) prior to injection into the stripper (24). The used absorption liquid solvent (UALS) is heated via heat exchange with the acidic gases (AG) output from the stripper (24). The second heat exchanger (26) cools the recycled absorption liquid solvent (RALS) before injection back into the contactor (12).

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NOR, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.

Disclosed is a process comprising: step a) contacting a feed stream comprising a contaminant with an absorbent stream in a counter-current flow to produce a contaminant depleted product stream depleted in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the feed stream, and a contaminant enriched absorbent stream enriched in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the absorbent stream; and step b) treating the contaminant enriched absorbent stream to form a gaseous stream comprising said contaminant and a regenerated absorbent stream lean in the molar quantity of said contaminant relative to the molar quantity of said contaminant in the contaminant enriched absorbent stream; herein said absorbent stream comprises at least 15 wt. % of at least one compound (A) of general formula (I) or a mixture (M) comprising at least one compound (B) of general formula (II) and at least one compound (C) of general formula (III).

Provided is a humidity control device capable of stably absorbing and desorbing moisture. The humidity control device includes: a moisture absorber causing a hygroscopic material to come into contact with air so that the hygroscopic material absorbs portion of moisture contained in the air, the hygroscopic material being in liquid and containing water, polyalcohol having hygroscopicity, and metal salt having hygroscopicity; and a composition controller controlling composition of the hygroscopic material. The composition controller controls the composition of the hygroscopic material to be within a range in which the hygroscopic material is capable of absorbing the moisture while the metal salt is kept from being deposited.

An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO.sub.2 absorption process is also provided, utilizing the biphasic solvent composition.

A scrubbing solution for removing contaminants, including particularly hydrogen sulfide, from a fluid. The scrubbing solution includes at least one scrubbing reagent which has a primary or secondary amine and an acid, which may be phosphoric acid. The fluid being scrubbed is passed through the scrubbing solution. The contaminants react with the scrubbing reagent securing them in the scrubbing solution. The fluid being scrubbed and the scrubbing solution are then separated. The scrubbing solution is heated and, if the scrubbing solution is under pressure, the pressure is reduced. The acid facilitates thorough removal of the contaminants, and especially the hydrogen sulfide, from the scrubbing solution. The scrubbing solution is then ready for reuse. Because the scrubbing solution is rendered substantially free of hydrogen sulfides, it can absorb other sulfide contaminants that might not otherwise be absorbed.

Methods of recovering iodine (I.sub.2) from a stream including iodine (I.sub.2) vapor and at least one of: an inert gas and water vapor can include contacting the stream with an alkaline solution to form an iodide salt, contacting the stream with an adsorbent to selectively adsorb water from the stream, contacting the stream with a concentrated acid to absorb the water vapor from the stream, desublimating or condensing the iodine (I.sub.2) vapor to form solid or liquid iodine (I.sub.2), or contacting the stream with a material to condense or de-sublimate the iodine (I.sub.2) vapor from the stream as the material at least one of: absorbs latent heat through a phase change of the material and absorbs sensible heat.