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.

Provided are a method for producing a purified gas, which, when a valuable material is generated from a waste-derived raw material gas, can efficiently remove a phase transitioning impurity contained in the raw material gas, a method for producing a valuable material, a gas purification apparatus, and an apparatus for producing a valuable material. A method for producing a purified gas, comprising removing an impurity in a waste-derived raw material gas, the method comprising: a solid-phased impurity removing step S11 of passing the raw material gas through a phase transitioning impurity removing unit to remove a solid-phased phase transitioning impurity in the raw material gas; and an impurity removing step S12 of passing the raw material gas after the solid-phased impurity removing step through a pressure swing adsorption apparatus combined with a vacuum pump to remove an impurity in the raw material gas.

An oxygen concentrator may have a compressor to feed a feed gas for sieve bed(s) via a first manifold, an accumulator to receive enriched air from the bed(s) via a second manifold. It may include an outer housing for the manifolds, the compressor, and the accumulator. The housing may include an access portal to a compartment therein, for removably receiving the bed(s) as a canister assembly. The first manifold may be adjacent to the compartment and have inlet coupling(s) for removably coupling respectively with inlet(s) of the canister assembly. The inlet coupling(s) may each have a first central axis. The second manifold may be adjacent to the compartment and have outlet coupling(s) for removably coupling respectively with outlet(s) of the canister assembly. The outlet coupling(s) may each having a second central axis. The first and second central axes may form any one of an obtuse, acute, or right angle.

An oxygen concentrator (100) may have a moisture conditioning system. In some implementations, the concentrator includes a compressor to induce feed gas into the concentrator. A first pathway may receive the feed gas from the compression system. The first pathway may be configured to draw moisture to produce moisture reduced feed gas. The first pathway may lead the moisture reduced feed gas to sieve bed(s) which produce oxygen enriched air with the moisture reduced feed gas. An accumulator may be configured to receive the produced oxygen enriched air from the sieve bed(s). A second pathway from the accumulator may apply the drawn-out moisture to the produced enriched air to produce humidified enriched air. A third pathway may transfer the drawn-out moisture from the first pathway to the second pathway. An outlet coupled with the second pathway may release the humidified enriched air from the concentrator for a user.

Solid sorbents, and especially zeolites, are attractive candidates for CO.sub.2 direct air capture (DAC) and point source capture applications because of their potential for high selectivity, fast kinetics, and low energy CO.sub.2 capture cycles. A common issue with solid sorbents, including zeolites, is their low thermal conductivity, which makes them difficult to heat for regeneration without using complex and expensive heat transfer systems. This invention utilizes a modified TVSA process which utilizes the product CO.sub.2 gas itself as the heating medium for the adsorbent bed, alone or in conjunction with internal or external heaters. The use of CO.sub.2 as a heating medium allows efficient heating of the sorbent bed and enables high purity CO.sub.2 product.

The invention relates to a method for regulating a unit for separating a gas stream, having P adsorbers, where P≥2, each following a PSA-type adsorption cycle with a phase time shift, the method involving the steps of operating the unit according to the nominal cycle when the required flow rate is equal to a nominal flow rate or optionally when the required flow rate is higher than the nominal flow rate, and operating the unit according to the reduced cycle when the required flow rate is lower than or equal to a predetermined flow rate, the predetermined flow rate being lower than the nominal flow rate.

The fluid chamber system can include: a chamber housing, a capture medium, an internal support structure, and/or any other suitable components. The system can optionally include a thermal management system. However, the system can additionally or alternatively include any other suitable set of components. The system preferably functions to direct an input fluid (e.g., vehicle exhaust) through the capture medium and/or harvest one or more target species (e.g., carbon dioxide) from the input fluid (e.g., vehicle exhaust).

An adsorbent bed, including at least one elementary composite structure that includes adsorbent particles in a polymer matrix, wherein the adsorbent bed has a bed packing, ρ.sub.bed, defined as a volume occupied by the at least one elementary composite structure V.sub.ecs divided by a volume of the adsorbent bed V.sub.bed where ρ.sub.bed is greater than 0.60.

Described is the use of a mineral comprising a metal carbonate fraction and a fuel fraction, such as oil shale or coal shale, in a calcination process. The disclosed process can advantageously result in carbon dioxide being removed from the atmosphere. Further, in the process, heat energy generated during calcination can be used to separate oxygen from air, so that the oxygen can be fed back into the system. Alternatively or in addition, heat energy may also be used to compress the gaseous carbon dioxide generated from the calcination process.

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