The present invention relates yolk-shell nanoparticles having both a high stability towards sintering and high H.sub.25 adsorption capacities, the use of the yolk-shell nanoparticles in a method for H.sub.2S removal from gas streams, and a corresponding method for H.sub.2S removal from gas streams also comprising the regeneration of the yolk-shell nanoparticles, wherein the yolk-shell nanoparticles provide for high H.sub.2 adsorption capacities and/or high reusability.

The present invention relates to an adsorbent comprising an alumina support and at least one alkali element, said adsorbent being obtained by introducing at least one alkali element, identical to or different from sodium, onto an alumina support the sodium content of which, expressed as Na.sub.2O equivalent, before the introduction of the alkali element or elements, is comprised between 1000 and 5000 ppm by weight with respect to the total weight of the support. The invention also relates to processes for the preparation of said adsorbent and use thereof in a process for the elimination of acidic molecules such as COS and/or CO.sub.2.

A novel adsorbent and contactor material based on polymer functionalized with amidoxime and alkylamines moieties. Methods of making the material are also described. The material can be easily processed into any desired sorbent geometry such as solid fibers, electrospun fibers, hollow fibers, monoliths, etc. The adsorbent exhibits a very high affinity toward acidic gases such CO.sub.2 and can be used in direct air capture, power plant-based CO.sub.2 capture, and industrial CO.sub.2 capture applications. The material can also serve as a contactor that accommodates other adsorbents within its structure.

A method of purifying gaseous mixtures, for example ternary or quaternary gaseous mixtures, using a sorbent media comprising two or more sorbent materials. The method involves obtaining a target gas from a gaseous composition comprising the target gas, a first gas and a second gas, and optionally further gases by contacting the gaseous composition with the sorbent media to remove at least some of the first gas and at least some of the second gas from the gaseous composition. The sorbent media comprises at least a first sorbent material and a second sorbent material; wherein the first sorbent material has a higher adsorption selectivity for the first gas than for the target gas; and wherein the second sorbent material has a higher adsorption selectivity for the second gas than for target gas. The method may be particularly useful for the separation of pure ethylene, methane or propylene from such gaseous mixtures. A sorbent media and an apparatus for obtaining a target gas from such a gaseous composition are also disclosed.

A nucleophilic substitution reaction to crosslink cyclodextrin (CD) polymer with rigid aromatic groups, providing a high surface area, mesoporous CD-containing polymers (P-CDPs). The P-CDPs can be used for removing organic contaminants from water. By encapsulating pollutants to form well-defined host-guest complexes with complementary selectivities to activated carbon (AC) sorbents. The P-CDPs can rapidly sequester pharmaceuticals, pesticides, and other organic micropollutants, achieving equilibrium binding capacity in seconds with adsorption rate constants 15-200 times greater than ACs and nonporous CD sorbents. The CD polymer can be regenerated several times, through a room temperature washing procedure, with no loss in performance.

Provided herein are water harvesting systems, as well as methods of making and using such systems, for capturing water from surrounding air using a design that reduces overall energy costs of the systems and improve water harvesting cycle efficiency. The systems and methods use sorbent materials, such as metal-organic frameworks, to adsorb water from the air. The systems and methods desorb this water in the form of water vapor, and the water vapor is condensed into liquid water and collected. The liquid water is suitable for use as drinking water.

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.

A plurality of carbonation plots are positioned in communication with atmospheric carbon dioxide to facilitate sequestration thereof via ambient weathering. The carbonation plots include a composition rich in metal oxides, which are positioned within the environment, such as on non-arable land, and exposed to the environment to react with carbon dioxide in the air and form metal carbonates. After about one year of exposure, the composition is recollected and calcined to produce a carbon dioxide stream and replenish the metal oxides, which can be redistributed in the carbonation plots to sequester additional carbon dioxide. The systems and methods of the present disclosure enable capture and redistribution of carbon dioxide for industrial-scale uses for very abundant quarry minerals and enable large-scale low-cost carbon capture projects for municipalities or corporations. CO.sub.2 removal from air via these methods and systems have a similar or lower cost than CO.sub.2 removal using DAC with synthetic sorbents or solvents.

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.