It is an objective of the present invention to provide a gas separation method by which a removal performance to remove a removal object gas component and a recovery rate to recover a recovery object gas component can be satisfied at the same time, and furthermore, a generation efficiency of a product gas can be improved. A raw material gas g0 is fed to one adsorption vessel 11 of an adsorbing device 10 and a permeated gas g1 is sent out. A pressure of the other the adsorption vessels 12 is made lower than a pressure during adsorption and a desorbed gas g2 is sent out. In accordance with an operating cycle of the adsorbing device 10 or according to a condition of the raw material gas g0 or the like, one of the permeated gas g1 and the desorbed gas g2 that has a lower concentration of a priority removal object gas component than the raw material gas g0 is provided as a return gas to the adsorbing device 10, the priority removal object gas component being a gas component to be preferentially removed.

It is an objective of the present invention to provide a gas separation method by which a removal performance to remove a removal object gas component and a recovery rate to recover a recovery object gas component can be satisfied at the same time, and furthermore, a generation efficiency of a product gas can be improved. A raw material gas g0 is fed to one adsorption vessel 11 of an adsorbing device 10 and a permeated gas g1 is sent out. A pressure of the other the adsorption vessels 12 is made lower than a pressure during adsorption and a desorbed gas g2 is sent out. In accordance with an operating cycle of the adsorbing device 10 or according to a condition of the raw material gas g0 or the like, one of the permeated gas g1 and the desorbed gas g2 that has a lower concentration of a priority removal object gas component than the raw material gas g0 is provided as a return gas to the adsorbing device 10, the priority removal object gas component being a gas component to be preferentially removed.

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.

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.

Disclosed are methods for removing acid gas from a feed stream of natural gas including acid gas, methane and ethane. The methods include alternating input of the feed stream between at least two beds of adsorbent particles comprising zeolite SSZ-13 such that the feed stream contacts one of the at least two beds at a given time in an adsorption step and a tail gas stream is simultaneously vented from another of the at least two beds in a desorption step. The contact occurs at a feed pressure of from about 50 to about 1000 psia for a sufficient period of time to preferentially adsorb acid gas from the feed stream. A product gas stream is produced containing no greater than about 2 mol % carbon dioxide and at least about 65 mol % of methane recovered from the feed stream and at least about 25 mol % of ethane recovered from the feed stream. The feed stream is input at a feed end of each bed. The product gas stream is removed from a product end of each bed. The tail gas stream is vented from the feed end of each bed. The methods require lower vacuum power consumption and allow improved hydrocarbon recoveries compared with known methods.

Disclosed are methods for removing acid gas from a feed stream of natural gas including acid gas, methane and ethane. The methods include alternating input of the feed stream between at least two beds of adsorbent particles comprising zeolite SSZ-13 such that the feed stream contacts one of the at least two beds at a given time in an adsorption step and a tail gas stream is simultaneously vented from another of the at least two beds in a desorption step. The contact occurs at a feed pressure of from about 50 to about 1000 psia for a sufficient period of time to preferentially adsorb acid gas from the feed stream. A product gas stream is produced containing no greater than about 2 mol % carbon dioxide and at least about 65 mol % of methane recovered from the feed stream and at least about 25 mol % of ethane recovered from the feed stream. The feed stream is input at a feed end of each bed. The product gas stream is removed from a product end of each bed. The tail gas stream is vented from the feed end of each bed. The methods require lower vacuum power consumption and allow improved hydrocarbon recoveries compared with known methods.

A medical gas production system produces from air a gas composition having a concentration of oxygen greater than the air for subsequent respiration by patients. The system includes a pair of treatment tanks, each containing an adsorbent bed for adsorbing gases from the air and a receiver tank for receiving an oxygen enriched gas mixture from the treatment tanks. A pair of transfer valves connected between receiver tank and respective ones of the treatment tanks control flow of gas from each treatment tank to the receiver tank, as well as enabling backflow of the gas mixture from the receiver tank to the treatment tank if a measured quality of the gas exiting the receiver tank falls below a prescribed threshold.

A medical gas production system produces from air a gas composition having a concentration of oxygen greater than the air for subsequent respiration by patients. The system includes a pair of treatment tanks, each containing an adsorbent bed for adsorbing gases from the air and a receiver tank for receiving an oxygen enriched gas mixture from the treatment tanks. A pair of transfer valves connected between receiver tank and respective ones of the treatment tanks control flow of gas from each treatment tank to the receiver tank, as well as enabling backflow of the gas mixture from the receiver tank to the treatment tank if a measured quality of the gas exiting the receiver tank falls below a prescribed threshold.

A portable gas separator assembly utilizing carbon molecular sieve absorbents or elements to separate a compressed air stream to extract nitrogen and oxygen molecules. Components of the assembly include at least two charging towers so that one tower can be charged with compressed gas while the other of the at least two towers is purged.