Primary, secondary (1°,2°) alkylethylenediamine- and alkylpropylenediamine-appended variants of metal-organic framework are provided for CO.sub.2 capture applications. Increasing the size of the alkyl group on the secondary amine enhances the stability to diamine volatilization from the metal sites. Two-step adsorption/desorption profiles are overcome by minimzing steric interactions between adjacent ammonium carbamate chains. For instance, the isoreticularly expanded framework Mg.sub.2(dotpdc) (dotpdc.sup.4−=4,4″-dioxido-[1,1′:4′,1″-terphenyl]-3,3″-dicarboxylate), yields diamine-appended adsorbents displaying a single CO.sub.2 adsorption step. Further, use of the isomeric framework Mg-IRMOF-74-II or Mg.sub.2(pc-dobpdc) (pc-dobpdc.sup.4−=3,3-dioxidobiphenyl-4,4-dicarboxylate, pc=para-carboxylate) also leads to a single CO.sub.2 adsorption step with bulky diamines. By relieving steric interactions between adjacent ammonium carbamate chains, these frameworks enable step-shaped CO.sub.2 adsorption, decreased water co-adsorption, and increased stability to diamine loss. Variants of Mg.sub.2(dotpdc) and Mg.sub.2(pc-dobpdc) functionalized with large diamines such as N-(n-heptyl)ethylenediamine have utility as adsorbents for carbon capture applications.

The invention relates to a method to produce a particulate activated carbon material for capturing CO.sub.2 from air, wherein the particulate activated carbon is impregnated with alkali carbonate salt such as K.sub.2CO.sub.3; and wherein the impregnated particulate activated carbon either has, determined using nitrogen adsorption methods, a pore volume of at least 0.10 cm.sup.3/g for pore sizes of at least 5 nm and a pore volume of at most 0.30 cm.sup.3/g for pore sizes of less than 2 nm or is based on a mixture of different alkali carbonate salts, or has a particular pore surface for pore sizes in the range of 2 nm-50 nm.

An activated carbon device for adsorbing solvent from a flow of air is regenerated by feeding heated inert gas to the activated carbon and by applying a reduced pressure to the heated activated carbon.

A compact, highly expandable sorbent made from polymeric materials is contemplated. The resulting sorbent can absorb more than 20 times its original volume owing to an internal foam-like structure having micron-level voids bisected by internal struts which themselves have nano-level pores. Further, this sorbent can be compressed and reused multiple times, thereby making it an ideal substance to facilitate separation of disparate fluids, such as oils floating on or within an aqueous solution.

The hydrogen storage product comprises one or more reduced-graphene oxide layers functionalized with a boron species and decorated with an alkali or alkaline earth metal. Each layer of the structure further comprises boron-oxygen functional groups comprising oxygen atoms bonded to boron atoms. The hydrogen storage product has a composition suitable for physisorption of hydrogen molecule, and operates to reversibly store hydrogen under operating conditions of low pressure and ambient temperature.

Methods of dewatering viscous materials are provided. The method comprises contacting the viscous material with pressurized carbon dioxide at a temperature and for a time wherein at least a fraction of water is expressed from the viscous material. Then the pressure is released, and the water expressed from the viscous material is removed to yield a dewatered product. Exemplary viscous materials that can be dewatered by the method include black liquor from wood pulping operations, wet lignin, wet super water absorbent polymers and sugar solutions. The pressurized carbon dioxide is present in subcritical or supercritical form. The method provides dewatering at reduced cost.

Provided is a method for recycling a water-absorbing resin which contains absorbed liquid, with consideration for a resource aspect and an energy aspect. The method for recycling a water-absorbing resin which contains absorbed liquid includes: discharging the absorbed liquid from the water-absorbing resin which contains the absorbed liquid; and recovering a water-absorbing power of the water-absorbing resin.

Methods of designing zeolite materials for adsorption of CO.sub.2. Zeolite materials and processes for CO.sub.2 adsorption using zeolite materials.

The invention relates to a cyclical method for producing a nitrogen fraction, the purity of which is greater than or equal to 95 mol %, and a hydrocarbon-enriched fraction from a filler containing nitrogen and a hydrocarbon, said method using a specific class of porous hybrid solids as an adsorbent in a pressure-swing adsorption (PSA) process. The invention also relates to equipment for implementing said method.

A system for capturing CO.sub.2 gas comprising: a gaseous feed stream having an initial concentration of the CO.sub.2 gas; wherein the gaseous feed stream is provided to a first reactor as a gaseous reaction stream; the first reactor comprising a sorbent composition and the gaseous reaction stream flowing therein, the gaseous reaction stream being in contact with the sorbent composition; and a first gaseous output stream having a concentration of CO.sub.2 being less than the initial concentration of CO.sub.2; wherein: the gaseous reaction stream comprises the CO.sub.2 gas and is characterized by a relative humidity of at least 5%; the sorbent composition comprises a metal carbonate material that reacts with the CO.sub.2 gas of the gaseous reaction stream thereby reducing CO.sub.2 gas concentration; and the first reactor comprises 35 wt. % or less of liquid water by weight of sorbent and liquid water.