An ammonia-producing system comprises a reactor that catalytically converts nitrogen and hydrogen feed gases to ammonia to form a reaction mixture of the ammonia, unreacted nitrogen gas, and unreacted hydrogen gas. A feed system feeds the nitrogen and hydrogen gases to the reactor at a reaction pressure of from about 9 to about 100 atmospheres. A reactor control system controls the temperature during conversion of the nitrogen and hydrogen to ammonia by maintaining a reaction temperature of from about 330 C. to about 550 C. An absorbent selectively absorbs at least a portion of the ammonia from the reaction mixture, and an absorbent control system controls one or both of a temperature and pressure at the absorbent during selective absorption of the ammonia from the reaction mixture. A recycle line downstream of the absorbent recycles the unreacted nitrogen and unreacted hydrogen to the reactor.

Systems and methods are provided for combined cycle power generation while reducing or mitigating emissions during power generation. Recycled exhaust gas from a power generation combustion reaction can be separated using a staged complementary swing adsorption process so as to generate a high purity CO.sub.2 stream while reducing/minimizing the energy required for the separation and without having to reduce the temperature of the exhaust gas. This can allow for improved energy recovery while also generating high purity streams of carbon dioxide and nitrogen.

Systems and methods for using pressure swing adsorption to separate and/or capture resulting emissions are provided. A stream of recycled exhaust gas is passed into a first swing adsorption reactor comprising a first adsorbent material which adsorbs CO.sub.2. An enriched N.sub.2 stream is recovered from a forward end of the first swing adsorption reactor. The pressure in the first swing adsorption reactor is reduced. The first swing adsorption reactor is purged with a portion of the first N.sub.2 stream recovered from the first swing adsorption reactor. The first purge output is passed to a second swing adsorption reactor comprising a second adsorbent material which adsorbs CO.sub.2. A second N.sub.2 stream is recovered from the second swing adsorption reactor. The pressure in the second swing adsorption reactor is reduced. The second swing adsorption reactor is purged with a steam purge.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing streams through adsorbent bed units to treat the feed stream to remove certain contaminants from the stream. In the method and system, active valves may be used with passive valves to manage the flow of the streams through the adsorbent bed units.

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.

An integrated temperature swing adsorption (TSA) process and gas fermentation process and device is disclosed. A heated tail gas stream from the gas fermentation process is used to heat and regenerate adsorbent in the TSA device. A portion of treated feedstock from the TSA device is used to cool the regenerated adsorbent. Integration of a tail gas stream from the gas fermentation zone used for regeneration of absorbent in the TSA eliminates the need for an inert gas regenerant and using TSA treated gas feedstock for cooling regenerated adsorbent allows for maximum recovery and use of available gas feedstock. Alternatively, when a pressure swing adsorption (PSA) process is also employed, a purge stream from the PSA may be used as regenerant in the TSA process.

A method for capturing CO.sub.2 from a gas mixture by dissolution in water is disclosed. The method comprises injecting the gas mixture as bubbles into a volume of water, allowing CO.sub.2 enriched water to exit out of the volume, and performing a depressurizing process of the CO.sub.2 enriched water. A corresponding system is also disclosed.

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.

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.

Aspects of the present invention relate to a gas treatment apparatus (1) for treating a process gas. The gas treatment apparatus (1) includes a primary treatment unit (2) and a secondary treatment unit (3), the primary and secondary treatment units (2, 3) being configured to treat the process gas. The primary treatment unit (2) includes a primary process gas inlet (10) for receiving the process gas, a first and a second primary adsorber (12, 13) for treating the process gas, and at least one primary process gas outlet for discharging the treated process gas from the first and the second primary adsorbers (12, 13). The secondary treatment unit (3) includes a secondary process gas inlet (30) for receiving the process gas, at least one secondary adsorber (32, 33) for treating the process gas, and at least one secondary process gas outlet (31) for discharging the treated process gas from the at least one secondary adsorber (32, 33) to the primary treatment unit (2). The primary treatment unit (2) is selectively configurable in a first operating mode and a second operating mode. When operating in the first operating mode, the primary process gas inlet (10) is connected to the first primary adsorber (12) to supply the process gas to the first primary adsorber (12) for treatment; and the second primary adsorber (13) is connected to the at least one secondary process gas outlet (31) to receive treated process gas from the secondary treatment unit (3) for regenerating the second primary adsorber (13). When operating in the second operating mode, the primary process gas inlet (10) is connected to the second primary adsorber (13) to supply the process gas to the second primary adsorber (13) for treatment; and the first primary adsorber (12) is connected to the at least one secondary process gas outlet (31) to receive treated process gas from the secondary treatment unit (3) for regenerating the first primary adsorber (12). Aspects of the present invention also relate to a method of controlling a gas treatment apparatus (1) to treat a process gas; and a liquid air energy storage plant.