A device and a method for producing hydrogen and byproduct oxygen by using green electricity electrolyzed water are provided. The device comprises an oxygen purifying system, a heat exchange system, an air separation compression and expansion system, an air separation rectification system and a liquid oxygen storage system. The method comprises the following steps: first, purifying oxygen prepared by electrolyzing water by green electricity to remove impurities such as hydrogen, carbon monoxide, carbon dioxide and water in the oxygen, then feeding the pure oxygen into the heat exchange system, performing heat exchange liquefaction to obtain liquid oxygen, coupling the liquid oxygen generated by rectification of the air separation rectification system, and obtaining pressurized oxygen through the heat exchange system and the air separation compression and expansion system.

A device and a method for recovering by-product oxygen from water-electrolysis hydrogen production using a low-temperature method are provided, solving the waste problem of by-product oxygen in the green water-electrolysis hydrogen production system. The device according to the present disclosure comprises an oxygen clarifying system, a pressurizing and heat exchanging system, and a circulating gas compression and expansion refrigeration system. The recovering method according to the present disclosure comprises the following steps: first clarifying and purifying the by-product oxygen from water-electrolysis hydrogen production is to remove hydrogen, carbon monoxide, carbon dioxide, water and other impurities in the oxygen; and then, liquefying, pressurizing and heat exchanging the pure oxygen to obtain the product oxygen and liquid oxygen with required pressure. In the whole process, the cooling capacity is provided by the circulating gas expansion refrigeration system.

A method of obtaining helium from a process gas. The process gas is at a pressure less than 15 bar to a first membrane separation stage having a first membrane more readily permeable for helium than for at least one other component in the process gas. A first retentate stream is fed to a second membrane separation stage having a second membrane more readily permeable for helium than for at least one other component in the process gas. Helium is separated from a first helium-containing permeate stream using a pressure swing adsorption to obtain a helium-containing product stream. A second helium-containing permeate stream is recycled to the first membrane separation stage. A purge gas from the pressure swing adsorption is also recycled to the first membrane separation stage.

A method is provided for refining an argon gas, in which oxygen is added to the argon gas containing hydrogen, carbon monoxide (CO), and oxygen as impurities so that the hydrogen and the CO are converted into water and carbon dioxide in a catalyst tower, or hydrogen is added to the argon gas so that the oxygen is converted into the water; the method including: monitoring the hydrogen, the CO, and the oxygen on an outlet side of the catalyst tower; and at least one of adding the oxygen to the argon gas when any one of the hydrogen and the CO is detected on the outlet side of the catalyst tower, and adding the hydrogen when the oxygen is detected, wherein the oxygen or the hydrogen to be added is intermittently added to the catalyst tower relative to continuous supply of the argon gas to the catalyst tower.

In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

The invention relates to a method for separating gases which comprises: a first step in which a gas fuel stream comprising combustible substances that produce gas products when oxidised, and an oxygen-rich inlet stream are passed through at least two modules of oxygen-separating ceramic membranes, such that the two streams come into contact through the membranes and exchange heat; a second step of selective diffusion of oxygen from the oxygen-rich stream to the fuel stream, such that the outlet streams from the membrane modules are an oxygen-depleted or completely oxygen-free stream and a partially or completely oxidised stream; and a third step of recovery of at least two separate outlet streams of at least two gases selected from oxygen, nitrogen, carbon dioxide and hydrogen.

A method for extending useful life of a sorbent for purifying a gas by sorption of an impurity is provided. The method generating a electrical discharge within the gas to obtain a spectral emission representative of a concentration of the impurity. The method also includes monitoring the concentration of the impurity according to the spectral emission. The method also includes lowering the concentration of the impurity by conversion of at least a portion of the impurity into a secondary impurity having a greater affinity to the sorbent than the impurity. The method also includes comparing the concentration of the impurity to a polluting concentration and managing the sorption of the gas onto the sorbent according to the comparison.

Process for the combined production of a mixture of hydrogen and nitrogen, and of carbon monoxide by cryogenic distillation and cryogenic scrubbing, wherein a methane-rich liquid is introduced at a first intermediate level of a scrubbing column as first scrubbing liquid and at least one nitrogen-rich liquid is introduced at a level higher than the first level of the scrubbing column as second scrubbing liquid and a mixture of hydrogen and nitrogen is drawn off as overhead gas from the scrubbing column.

In a helium purification process, a stream containing at least 10% of helium, at least 10% of nitrogen in addition to hydrogen and methane is separated to form a helium-enriched stream containing hydrogen, a first stream enriched in nitrogen and in methane and a second stream enriched in nitrogen and in methane, the helium-enriched stream is treated to produce a helium-rich product and a residual gas containing water, the residual gas is treated by adsorption (TSA) to remove the water and the regeneration gas from the adsorption is sent to a combustion unit (O).

In a method for separating a synthesis gas containing carbon monoxide and hydrogen, a synthesis gas flow from a synthesis gas source is compressed in a compressor and separated into at least three gaseous products. If there is insufficient synthesis gas, at least three separation products are recycled in the compressor in order to separate said products.