The implementations described herein generally relate to methods and chemical compositions for scavenging sulfur-containing compounds, and more particularly to methods and compositions for scavenging, for example, H.sub.2S and mercaptans from sulfur-containing streams. In one implementation, a method for scavenging a sulfur-containing compound from a sulfur-containing stream is provided. The method comprises contacting the sulfur-containing stream with a scavenging system for scavenging the sulfur-containing compound, wherein the scavenging system comprises urea formaldehyde reaction products.

A method for removing carbon dioxide from a gaseous source, the method comprising: (i) contacting said gaseous source with an aqueous solution of a carbon dioxide sorbent that reacts with carbon dioxide to form an aqueous-soluble carbonate or bicarbonate salt of said carbon dioxide sorbent; (ii) contacting the aqueous solution from step (i) with a bis-iminoguanidine carbon dioxide complexing compound, which is different from the carbon dioxide sorbent, to result in precipitation of a carbonate or bicarbonate salt of said carbon dioxide complexing compound and regeneration of the carbon dioxide sorbent; and (iii) removing the precipitated carbonate or bicarbonate salt from the aqueous solution in step (ii) to result in a solid form of said carbonate or bicarbonate salt of the carbon dioxide complexing compound. The method may further include a step (iv) of regenerating the carbon dioxide complexing compound by subjecting the precipitated salt to sufficient heat and/or vacuum.

The present invention relates to novel molecules suitable to the use in the separation/removal of carbon dioxide from gaseous mixtures as liquid-phase carbon dioxide absorbers and suitable to allow the subsequent release of the absorbed carbon dioxide in form of different ionic liquids, preferentially a glycine salt with choline hexanoate, ester between glycine and hexanoic alcohol (hexyl glycinate) and glycerol ester with glycine and hexanoic acid. The present invention also relates to a method and a plant for the capture of carbon dioxide from gaseous mixtures by using an absorber for carbon dioxide in liquid phase with a heating jacket.

Aspects of this disclosure are directed to methods, apparatuses and approaches involving the use of a moisture absorbing material (e.g., desiccant) to control moisture. As may be implemented consistent with one or more embodiments, moisture is removed from an environmental control module that includes a desiccant material contained within a package. Liquid is deposited inside the package and sealed with the desiccant in the package.

Methods of scavenging formaldehyde from passing air such as in the interior of buildings by exposing a cured coating composition to passing air. The coating composition includes a binder, pigment, and a formaldehyde scrubbing urea compound. A cured coating formed from the coating composition absorbs formaldehyde and other air pollutants from passing air.

Certain functionalized aldehydes scavengers may be used to at least partially scavenge sulfur-containing contaminants from fluid systems containing hydrocarbons and/or water. The contaminants scavenged or otherwise removed include, but are not necessarily limited to, H.sub.2S, mercaptans, and/or sulfides. Suitable scavengers include, but are not necessarily limited to, reaction products of glycolaldehyde with aldehydes; reaction products of glycolaldehyde with a nitrogen-containing reactant (e.g. an amine, a triazine, an imine, an aminal, and/or polyamines); non-nitrogen-containing reaction products of a hydrated aldehyde with certain second aldehydes; reaction products of 1,3,5-trioxane with hydroxyl-rich compounds (e.g. glyoxal, polyethylene glycol, polypropylene glycol, pentaerythritol, and/or sugars); and reaction products of certain aldehydes with certain phenols; and combinations of these reaction products.

Methods for scavenging carbon disulfide (CS.sub.2) from hydrocarbon streams using treatment compositions comprising at least one CS.sub.2 scavenger and at least one phase transfer catalyst therein. The CS.sub.2 scavenger may comprise at least one polyamine with the general formula: H.sub.2N(R.sub.1NH).sub.xR.sub.2(NHR.sub.3).sub.yNH.sub.2 wherein R.sub.1, R.sub.2, R.sub.3 may be the same or different H, aryl or C.sub.1-C.sub.4 alkyl; and x and y may be integers from 0 to 10. A hydrocarbon product with a reduced concentration of CS.sub.2 therein.

The use of a chemical composition in degassing of vessels is taught, said chemical composition comprising 1-10% by weight of an oxyalkylated dodecyl thiol; and 1-20% by weight of an alkyl di-substituted 9-decenamide. A method is further provided for degassing a vessel. The method comprises charging said vessel with chemical composition and a carrier medium, wherein said chemical composition comprises 1-10% by weight of an oxyalkylated dodecyl thiol and 1-20% by weight of an alkyl di-substituted 9-decenamide.

A variety of methods and systems are disclosed, including, in one example, a method of direct air capture including: introducing an air stream comprising carbon dioxide into gas-liquid contactor; contacting the air stream with a treatment fluid comprising a surfactant, wherein the carbon dioxide is at least partially soluble in the treatment fluid, and wherein the carbon dioxide reacts with the treatment fluid to form a reaction product; performing an ion exchange reaction between the reaction product and a base in the presence of the surfactant to form an ion exchange product; and precipitating the ion exchange product to form a precipitate.

A moisture control material comprises a salt composed of a specific triazolium cation and a phosphate ester anion.