Hygroscopic hydrogels including a cross-linked polymer, the polymer being prepared by polymerization of one or more monomers, wherein at least one of the monomers is a compound of formula I, are provided. Related monomers and polymers, as well as methods for the production and use thereof, are also provided. Hygroscopic hydrogels as described herein may be used for water harvesting, for example. (I) (formula I)

##STR00001##

A solvent and method for removing carbon dioxide from a gaseous mixture flow with high carbon dioxide partial pressures are disclosed. The solvent includes a secondary or tertiary amine, an amine activator, a physical solvent (e.g., thioalkanol), and a carbonate buffer. The solvent contains less than about 60% by weight of water and is in a single liquid phase.

Disclosed is an absorbent containing an amine for absorption of an acid gas in a biogas, and a biogas purification system using the same.

A non-aqueous solvent system configured to remove acidic gas from a gas stream comprises a solution formed of a chemical absorption component and a physical absorption component. The chemical absorption component includes a nitrogenous base, wherein the nitrogenous base has a structure such that it reacts with a portion of the acidic gas. The physical absorption component includes an organic diluent that is non-reactive with the acidic gas and that has a structure such that it absorbs a portion of the acidic gas at a pressure above atmospheric pressure. The solvent system has a solubility with water of less than about 10 g of solvent per 100 mL of water.

Capture of hydrogen sulfide from a gas mixture may be accomplished using an aqueous solution comprising an amine. Certain sterically hindered amines may selectively form a reaction product with hydrogen sulfide under kinetically controlled contacting conditions and afford a light phase and a heavy phase above a critical solution temperature, wherein the hydrogen sulfide may be present in either phase. Upon separation of the light phase from the heavy phase, processing of one of the phases may take place to remove hydrogen sulfide therefrom. Recycling of the amine to an absorber tower may then take place to promote capture of additional hydrogen sulfide.

A system and method to both reduce interior levels of volatile organic compounds and carbon dioxide that is more energy efficient than increasing building ventilation rates. The system comprises a carbon dioxide scrubber that operates in a continuous manner, and optionally but preferably further comprises an air purifier.

The disclosure provides an apparatus, as well as associated systems and methods for removing acid gas components from gas streams. The disclosure provides a rotating packed bed (RPB)-based absorber with a non-aqueous liquid solvent contained therein for treatment of the gas streams, wherein the non-aqueous liquid solvent captures acid components from the gas stream. Various advantages, e.g., with respect to spatial considerations and associated expenses can be realized using the apparatus, systems, and methods described herein.

The disclosure concerns a process for producing formic acid, having (a) a carbon capture step in which a source of carbon dioxide is contacted with an amine solution in a closed-top scrubber, to obtain an ammonium bicarbonate solution; (b) inducing crystallization in the ammonium bicarbonate solution to obtain a concentrated ammonium bicarbonate solution; (c) subjecting the concentrated ammonium bicarbonate solution to a hydrogenation step to obtain an ammonium formate; and (d) heating the ammonium formate to a temperature in the range of 50-150° C., to obtain a gaseous product containing the amine and a liquid product stream containing formic acid. The source of carbon dioxide has a carbon dioxide content of at least 95 vol % and the amine used in step (a) and reformed in step (d) has a partial vapour pressure above a 40 wt % solution of the amine in water at 20° C. of at least 40 kPa. The disclosure further concerns a system for performing the process.

The disclosure provides an apparatus, as well as associated systems and methods for removing acid gas components from gas streams. The disclosure provides a rotating packed bed (RPB)-based absorber with a non-aqueous liquid solvent contained therein for treatment of the gas streams, wherein the non-aqueous liquid solvent captures acid components from the gas stream. Various advantages, e.g., with respect to spatial considerations and associated expenses can be realized using the apparatus, systems, and methods described herein.

The invention provides a process for regenerating a liquid absorbent, including: contacting the liquid absorbent with a hydrophobic medium, wherein the liquid absorbent includes at least one amine of Formula (I) ##STR00001##
and degradation product thereof including at least one imine of Formula (II), ##STR00002##
wherein each Ar is independently an aromatic group and each R is independently selected from hydrogen, an organyl group and NH2; and selectively extracting the degradation product into or through the hydrophobic medium.