A method is disclosed for separating compressed dry air to provide carbon dioxide and reduced-carbon dioxide compressed dry air. The method comprises providing a source of compressed dry air and admitting compressed dry air into a first chamber containing a carbon dioxide-adsorbent material at a first temperature. The carbon dioxide-adsorbent material adsorbs carbon dioxide from the compressed dry air to form reduced-carbon dioxide compressed dry air, which is allowed to pass out of the first chamber. The first chamber is closed to the source of compressed dry air. Then the carbon dioxide-adsorbent material is heated to a second temperature. This releases carbon dioxide from the carbon dioxide-adsorbent material, which carbon dioxide is removed from the first chamber. The method may be low cost and low energy, and may be easily integrated into existing compressed dry air systems. A carbon dioxide capture unit and a compressed dry air production system for separating compressed dry air to provide carbon dioxide and reduced-carbon dioxide compressed dry air are also described.

When the product gas producing operation is stopped, a stand-by operation is executed in which a product gas filling up a reforming processing unit is circulated, in a state in which an adsorbent of adsorption towers is maintained in a state in which adsorption target components are desorbed, and the heating of a reformer by a heating burner is maintained, and when the stand-by operation is stopped and the product gas producing operation is started, initial operation processing is executed in which immediately after the start, a source gas and steam are supplied to the reformer to produce a reformed gas, and the reformed gas from the reforming processing unit supplied to the adsorption towers to produce the product gas, and then the product gas producing operation in which the product gas is collected in a product gas tank is executed.

When the product gas producing operation is stopped, a stand-by operation is executed in which a product gas filling up a reforming processing unit is circulated, in a state in which an adsorbent of adsorption towers is maintained in a state in which adsorption target components are desorbed, and the heating of a reformer by a heating burner is maintained, and when the stand-by operation is stopped and the product gas producing operation is started, initial operation processing is executed in which immediately after the start, a source gas and steam are supplied to the reformer to produce a reformed gas, and the reformed gas from the reforming processing unit supplied to the adsorption towers to produce the product gas, and then the product gas producing operation in which the product gas is collected in a product gas tank is executed.

A hydrogen gas supply apparatus includes a compressor configured to compress hydrogen gas and supply the compressed hydrogen gas toward a pressure accumulator which accumulates the hydrogen gas, a first adsorption column disposed between the discharge port of the compressor and the pressure accumulator and configured to include the first adsorbent for adsorbing impurities in the hydrogen gas discharged from the compressor, a first valve disposed between the discharge port of the compressor and the gas inlet port of the first adsorption column, a second valve disposed between the gas outlet port of the first adsorption column and the pressure accumulator, a return pipe configured to branch from between the first valve and the gas inlet port of the adsorption column and connect to the suction side of the compressor, and a second adsorption column disposed in the middle of the return pipe.

Disclosed are techniques such as roll to roll processing to produce membrane valves in microelectromechanical systems that are integrated with micro-pumps that include a pump body having compartmentalized pump chambers. One application of this technology is as a valve assembly for a gas concentrator that includes a first micro pump for feeding an input gas stream, a second micro pump to supplying a vacuum and at least one sieve bed having a zeolite. The gas concentrator uses the valve assembly for controlling entry of gas from the first micro pump into the sieve bed and the second micro pump to vent.

A portable pressure swing adsorption system and method for fuel gas conditioning. A fuel gas conditioning system includes a pressure swing adsorption (PSA) system fluidly coupled to a compressed rich gas stream, the PSA system including a plurality of adsorbent beds and configured to condition the compressed rich natural gas stream and produce therefrom a high-quality fuel gas and gaseous separated heavier hydrocarbons, a product end of the adsorbent beds fluidly coupled to a fuel gas line, and a feed end of the adsorbent beds configured to be fluidly coupled to the compressed rich natural gas stream or a raw natural gas stream, wherein the produced gaseous separated heavier hydrocarbons are desorbed at at least 50 psia and recirculated into the rich natural gas stream or the raw natural gas stream without post-desorption compression.

A portable pressure swing adsorption system and method for fuel gas conditioning. A fuel gas conditioning system includes a pressure swing adsorption (PSA) system fluidly coupled to a compressed rich gas stream, the PSA system including a plurality of adsorbent beds and configured to condition the compressed rich natural gas stream and produce therefrom a high-quality fuel gas and gaseous separated heavier hydrocarbons, a product end of the adsorbent beds fluidly coupled to a fuel gas line, and a feed end of the adsorbent beds configured to be fluidly coupled to the compressed rich natural gas stream or a raw natural gas stream, wherein the produced gaseous separated heavier hydrocarbons are desorbed at at least 50 psia and recirculated into the rich natural gas stream or the raw natural gas stream without post-desorption compression.

A process for converting post-explosion gases of an inhabitable level, low-oxygen ambient environment to a breathable mixture for human consumption comprises receiving a flow of post-explosion gas with oxygen, carbon dioxide, carbon monoxide, nitrogen, and methane. The oxygen, carbon monoxide, and carbon dioxide are removed from the from the flow of post-explosion gas to create both a mixture including oxygen, carbon monoxide, and carbon dioxide; and a residual stream including nitrogen and methane. The oxygen is removed from the mixture of oxygen, carbon monoxide, and carbon dioxide, and concentrated in a primary oxygen storage canister. The nitrogen is removed from the residual stream and stored in a nitrogen storage canister separate from the oxygen storage canister. The methane is vented back to the inhabitable level, low-oxygen ambient environment. The stored oxygen and nitrogen are metered through a breathing mask at a habitable level of 19-21% oxygen to a user.

A passive valve for use as a fixed leak valve. The valve includes a body having an internal chamber, first and second body ports in fluid communication with the chamber with the first port configured for fluid communication with a patient connection and the second body port configured for fluid communication with a ventilator, a body passageway in fluid communication with the chamber and with ambient air exterior of the body, and a check valve seal positioned to seal the body passageway to permit the flow of gas within the chamber through the body passageway to the exterior of the body and to prevent the flow of ambient air exterior of the body through the body passageway into the chamber. In alternative embodiments, the valve is incorporated into the patient connection or constructed as a separate part connectable to the patient connection.

Systems and methods are provided that obtain the same or better level of performance by using lower operating flow rates and pressures within the system. This extends the life of system components and lower energy consumption. In one embodiment, gas separation (or sieve) beds that are used to separate gaseous components are provided that have lower flow and pressure requirements compared to conventional beds. The sieve beds include, for example, a diffuser having low solid area in cross-section and maximum open area for flow while providing adequate mechanical properties to contain sieve material and support filter media. In another embodiment, systems and methods are provided having an indicator when a component has been serviced or repaired. This provides an indication whether the component has been tampered with in any manner. This allows the manufacturer to determine if the component was serviced, repaired, or tampered with outside the manufacturer's domain.