A scrubbing solution for removing contaminants, including particularly hydrogen sulfide, from a fluid. The scrubbing solution includes at least one scrubbing reagent which has a primary or secondary amine and an acid, which may be phosphoric acid. The fluid being scrubbed is passed through the scrubbing solution. The contaminants react with the scrubbing reagent securing them in the scrubbing solution. The fluid being scrubbed and the scrubbing solution are then separated. The scrubbing solution is heated and, if the scrubbing solution is under pressure, the pressure is reduced. The acid facilitates thorough removal of the contaminants, and especially the hydrogen sulfide, from the scrubbing solution. The scrubbing solution is then ready for reuse. Because the scrubbing solution is rendered substantially free of hydrogen sulfides, it can absorb other sulfide contaminants that might not otherwise be absorbed.

A scrubbing solution for removing contaminants, including particularly hydrogen sulfide, from a fluid. The scrubbing solution includes at least one scrubbing reagent which has a primary or secondary amine and an acid, which may be phosphoric acid. The fluid being scrubbed is passed through the scrubbing solution. The contaminants react with the scrubbing reagent securing them in the scrubbing solution. The fluid being scrubbed and the scrubbing solution are then separated. The scrubbing solution is heated and, if the scrubbing solution is under pressure, the pressure is reduced. The acid facilitates thorough removal of the contaminants, and especially the hydrogen sulfide, from the scrubbing solution. The scrubbing solution is then ready for reuse. Because the scrubbing solution is rendered substantially free of hydrogen sulfides, it can absorb other sulfide contaminants that might not otherwise be absorbed.

A system for pressure swing adsorption including: a plurality of beds each performing at least one of an adsorbing process, a pressure equalizing process, a vacuum process, or a pressurizing process; a supply valve provided in each of the beds and connected to a mixed gas supply unit to supply a mixed gas to the bed; a discharge valve provided in each of the beds and connected to a hydrogen gas discharge unit to discharge hydrogen generated in the bed; a vacuum valve provided in each of the beds and connected to a vacuum pump so as to be open to the vacuum pump during the vacuum process of the bed; and a control unit that controls the supply valve, the discharge valve, and the vacuum valve to allow each of the beds to perform the adsorbing process, the pressure equalizing process, the vacuum process, or the pressurizing process.

Methods and systems for capture of CO.sub.2 from a hydrated gaseous stream are described. Systems can be utilized for direct air capture of CO.sub.2 and incorporate a low energy temperature-vacuum swing adsorption (TVSA) process. A TVSA process can include a multi-step CO.sub.2 capture bed regeneration process that includes depressurization of the bed, heating of the bed, venting and purging of the bed, and cooling of the bed. Multiple beds can be cycled between CO.sub.2 capture and regeneration, during which captured CO.sub.2 is recovered. Off-gas from a CO.sub.2 capture bed can be used in regenerating a parallel bed for increased efficiency.

One embodiment of the present invention sets forth a technique for operating an oxygen concentrator. The technique includes measuring a product gas within an oxygen concentrator to produce a product gas measurement, and determining that an output of the oxygen concentrator is fluidly connected to a respiratory ventilation device based on the product gas measurement. The technique further includes, in response to determining that the oxygen concentrator is fluidly connected to the respiratory ventilation device, determining that the output of the oxygen concentrator does not meet a supply gas requirement of the respiratory ventilation device and, in response to determining that the output of the oxygen concentrator does not meet the supply gas requirement, adjusting a control output in the oxygen concentrator to modify operation of the oxygen concentrator.

According to an exemplary embodiment of the present invention, a pressure swing adsorption process of a hydrogen production system is provided. The hydrogen production system includes a desulfurization process for removing sulfur components from raw natural gas; a reforming reaction process for producing a reformed gas containing hydrogen generated by the reaction of natural gas through the desulfurization process and steam; and a pressure swing adsorption process of concentrating the hydrogen using a pressure swing adsorption from the reformed gas. In a desorption step of the pressure swing adsorption process, a cocurrent depressurization and a countercurrent depressurization are simultaneously performed.

Pressure swing adsorption process for reducing fluctuations in the flow rate of tail gas from the adsorption unit and reducing fluctuations in the stoichiometric oxidant flow rate required to completely combust the tail gas in a reformer furnace. Constant flow rate and constant fuel property can be obtained by intelligent mixing designs.

A system for pressure swing adsorption including: a plurality of beds each performing at least one of an adsorbing process, a pressure equalizing process, a vacuum process, or a pressurizing process; a supply valve provided in each of the beds and connected to a mixed gas supply unit to supply a mixed gas to the bed; a discharge valve provided in each of the beds and connected to a hydrogen gas discharge unit to discharge hydrogen generated in the bed; a vacuum valve provided in each of the beds and connected to a vacuum pump so as to be open to the vacuum pump during the vacuum process of the bed; and a control unit that controls the supply valve, the discharge valve, and the vacuum valve to allow each of the beds to perform the adsorbing process, the pressure equalizing process, the vacuum process, or the pressurizing process.

According to one aspect of the present invention, a pressure swing adsorption (PSA) device includes an adsorption tower configured to introduce hydrogen gas and adsorb impurity components in the hydrogen gas by using a pressure swing adsorption (PSA) method, an adsorbent of one layer made of activated carbon or an adsorbent of two layers in which activated carbon and zeolite are stacked being disposed in the adsorption tower, the hydrogen gas containing carbon monoxide (CO) of 0.5 vol % or more and 6.0 vol % or less and methane (CH.sub.4) of 0.4 vol % or more and 10 vol % or less as the impurity components; and a densitometer configured to detect a concentration of CO in the hydrogen gas discharged from the adsorption tower, wherein the impurity components are adsorbed and removed to cause the CO concentration measured by the densitometer to fall below a threshold.

Pressure swing adsorption process for reducing fluctuations in the flow rate of tail gas from the adsorption unit. The flow rate of the stream of blowdown gas is regulated responsive signals from a sensor measuring the pressure and/or flow rate of the tail gas comprising the blowdown gas and purge gas effluent before the tail gas is introduced into a surge vessel.