Provided are an oxygen concentrator, a control method, and a control program capable of preventing an internal pressure drop of the concentrated oxygen gas tank in order to extract concentrated oxygen gas at a predetermined flow rate. An oxygen concentrator capable of preventing a pressure drop in both cylinders in the pressure equalization step and, as a result, preventing a drop in the internal pressure of a concentrated oxygen gas tank, by starting pressurization in advance in the already depressurized adsorption cylinder before the pressure equalization step.

A method and system for purification of helium and CO.sub.2 from a stream containing at least Helium, CO2, nitrogen or methane uses a combination of cryogenic, membrane and adsorption technologies.

A process for something separating oxygen from air includes mixing the air with hydro fluoro ether in a closed vessel for a desired period of time so that the oxygen from the air is adsorbed into the hydro fluoro ether, discharging the oxygen-adsorbed hydro fluoro ether from the closed vessel, and flashing the oxygen-adsorbed hydro fluoro ether into a chamber so that so as to separate the oxygen from the hydro fluoro ether. Nitrogen is separated from the air as the oxygen is adsorbed in the hydro fluoro ether in the closed vessel. The step of flashing that includes passing the elevated pressure oxygen-adsorbed hydro fluoro ether across a restricting orifice so as to evaporate the oxygen from the hydro fluoro ether.

Processes and systems for the energy efficient capture of CO.sub.2 from a flue gas stream such as produced or resulting from power plant operation, are provided. The processes and systems integrate the use of high CO.sub.2/N.sub.2 selectivity membranes and high CO.sub.2 flux membranes, to capture CO.sub.2. Useful membranes can desirably be graphene oxide-based membranes.

The invention relates to the use of biomethanol from the pulp industry in the production of biohydrogen. The preferred biomethanol comprises purified biomethanol derived from black liquor. The invention also relates to a process for the production of biohydrogen from crude biomethanol recovered from black liquor and to a process for producing hydrocarbon biofuel using such biohydrogen as a hydrogen source. The invention further relates to a biofuel production facility for producing fuel from biohydrogen and biohydrocarbon, and to biofuel so produced. The invention makes it possible to produce a biofuel, wherein 100% of the raw material stems from non-fossil sources.

Disclosed herein are new processes for adsorbing oxygen using adsorbent compositions comprising RHO zeolites kinetically selective for oxygen. The RHO zeolites can be used in pressure swing adsorption processes for separating oxygen from oxygen containing streams, such as for, but not limited to, purifying a crude argon feed stream or separating oxygen from an air feed stream.

Process and apparatus for producing helium, neon, or argon product gas using an adsorption separation unit having minimal dead end volumes. A purification unit receives a stream enriched in helium, neon, or argon, and a stream is recycled from the purification unit back to the adsorption separation unit in a controlled manner to maintain the concentration of the helium, neon, or argon in the feed to the separation unit within a targeted range.

An apparatus and a process to recover high purity helium from a low helium content feed stream are disclosed. The apparatus includes a first dual reflux pressure swing adsorption (DRPSA) unit and a second DRPSA unit, each unit comprising a high pressure adsorption column and a low pressure adsorption column configured in fluid communication with the high pressure adsorption column. The first DRPSA unit is arranged to receive and separate the feed stream into a first reflux product and a first heavy product and circulate the first reflux product and the first heavy product between the high and low pressure adsorption columns to produce an intermediate helium-enriched stream. The second DRPSA unit is arranged to receive and separate the intermediate helium-enriched stream into a second reflux product and a second heavy product and circulate the second reflux product and the second heavy product between the high and low pressure adsorption columns to produce a high purity helium stream and a waste stream containing helium. The waste stream from the second DRPSA unit is recycled to one of a plurality of locations in the first DRPSA unit to increase helium recovery in the high purity helium stream produced in the second DRPSA unit.

A method and apparatus for the oxy-combustion of fuel in an internal combustion engine (ICE) used to power a vehicle includes one or more air separation devices that separate oxygen from the atmospheric air to mix with the fuel and return the nitrogen to the atmosphere and converts the free energy available in the form of waste heat from the engine exhaust gas stream and coolant system on board the vehicle into electrical and/or mechanical energy, which energy is used to separate oxygen from air to eliminate or significantly reduce the volume of nitrogen entering the ICE's combustion chamber, and thereby reduce NO.sub.x pollutants released into the atmosphere and increase the concentration of CO.sub.2 in the engine exhaust stream for capture using an integrated system to compress and increase the density of the captured CO.sub.2 for temporary on-board storage until it is discharged at a recovery station, e.g., during vehicle refueling.

Systems and methods are provided for separating oxygen from air using a sorption/desorption cycle that includes a reduced or minimized difference between the maximum and minimum pressures involved in the sorption/desorption cycle. The reduced or minimized difference in pressures can be achieved in part by using valves that can allow for commercial scale flow rates while avoiding large pressure drops for flows passing through the valves. A rotary wheel adsorbent is an example of a system that can allow for a sorption/desorption cycle with reduced and/or minimized pressure drops across valves associated with the process. Stationary adsorbent beds can also be used in combination with commercially available valves that have reduced and/or minimized pressure drops.