The present disclosure relates to a pressure swing adsorption apparatus for hydrogen purification from decomposed ammonia gas and a hydrogen purification method using the same, and more particularly, the pressure swing adsorption apparatus of the present disclosure includes a plurality of adsorption towers including a pretreatment unit and a hydrogen purification unit wherein the adsorption towers of the pretreatment unit and the hydrogen purification unit are packed with different adsorbents, thereby achieving high purity hydrogen purification from mixed hydrogen gas produced after ammonia decomposition, making it easy to replace the adsorbent for ammonia removal, minimizing the likelihood that the lifetime of the adsorbent in the hydrogen purification unit is drastically reduced by a very small amount of ammonia, and actively responding to a large change in ammonia concentration in the raw material. Additionally, a hydrogen purification method using the pressure swing adsorption apparatus of the present disclosure physically adsorbs and removes impurities such as moisture (H.sub.2O), ammonia (NH.sub.3) and nitrogen (N.sub.2) included in mixed hydrogen gas produced after ammonia decomposition below extremely small amounts, thereby achieving high purity hydrogen purification with improved selective adsorption of moisture, ammonia and nitrogen and maximized hydrogen recovery rate and productivity. In addition, since the temperature swing adsorption process is not introduced, there is no need for a heat source for regeneration, thereby reducing the driving cost.

An oxygen concentrator includes an adsorption cylinder and a humidifying device. The adsorption cylinder has an adsorbent that selectively adsorbs nitrogen from raw air and generates high-concentration oxygen. The humidifying device humidifies the generated high-concentration oxygen. The humidifying device includes a winding body composed of a humidifying tube that supplies moisture present outside to the high-concentration oxygen flowing through an interior. The winding body is formed by winding the single humidifying tube around a virtual axis.

An oxygen concentrator device comprising at least 2 separation vessels with a feed end and a product end, and a set of manifolds comprising at least one feed manifold attached to the feed end of the separation vessels and at least one equalization manifold attached to the product end of the separation vessels. The feed manifold comprises compression ports and valving; vacuum ports and valving; and, an upstream headspace equaling 2-6% of the total sorbent volume in the combined sieve beds. The equalization manifold comprises equalization ports and valving; and, a downstream headspace equaling 2-6% of the total sorbent volume in the combined sieve beds. The ratio of compression, vacuum, and equalization Cv to total sorbent volume is

[00001]$0.0005-0.005\left(\frac{\mathrm{gal}}{\min }\right)\left(\frac{1}{L_S}\right).$

Also, a method for concentrating oxygen, providing the set of manifolds described above and operating the oxygen concentrator without separately purging the sieve bed with an unused gas.

A solid amino acid salt sorbent for removing CO.sub.2 from a CO.sub.2 containing gas comprises an amino acid constituent and an alkali metal constituent. The solid amino acid salt sorbent comprises one or more of potassium taurine salt, sodium proline salt, sodium taurine salt, sodium lysine salt, potassium lysine salt, lithium lysine salt, potassium glycine salt, sodium glycine salt, lithium glycine salt, histidine sodium salt, taurine sodium salt, aspartic acid sodium salt, asparagine sodium salt, alanine sodium salt, or leucine sodium salt. The sorbent may further comprise a support component arranged in a structural relationship with the amino acid and alkali metal constituents.

A direct air capture (DAC) system includes: a sorbent chamber housing a set of sorbent beds; a conductive heating subsystem; and a purging subsystem. The sorbent beds: arrange vertically within the sorbent chamber; define a set of radial interstices between vertically adjacent sorbent beds; and extend radially about a vertical manifold defining a set of manifold apertures. The conductive heating subsystem includes a set of thermally conductive heating coils arranged within a sorbent bed in the set of sorbent beds; and configured to circulate a thermally conductive heating fluid to heat the sorbent bed. The purging subsystem includes a set of purging coils configured to distribute a purging fluid via a set of purging nozzles to a sorbent bed; and arranged above the sorbent bed.

A carbon dioxide removal system includes: a flow path through which a target gas flows; a treatment unit including adsorption towers connected in series in the flow path; and a control device that switches between paths of the target gas. The flow path includes: a first main path that supplies the target gas to the treatment unit; a first recovery path that discharges, to a target space, the target gas passed through the first main path; a desorption path connected to the adsorption towers; a first branch path that connects a path between the adsorption towers on upstream and downstream sides to the first recovery path; and a switching mechanism that switches a path through which the target gas flows. The desorption path is connectable in parallel to the adsorption towers.