Hitachi, Ltd.

Masaomi Tomomura

Shunsuke Nogita

Kazuo Someya

Takazumi Ishizu

Tetsuro Haga

Kiyoshi Ichihara

Osamu Kita

Misayo Ohtani

Highly pure argon is obtained from an argon waste gas composition by adding a stoichiometrically excess amount of oxygen to the waste gas composition to combust hydrogen and the like impurities and to convert into water and carbon dioxide, adding a stoichiometrically excess amount of a hydrocarbon gas to the resulting gas composition to remove the residual oxygen by the reaction with the oxygen and the hydrocarbon gas so as to convert into water and carbon dioxide, and subjecting the resulting gas composition to a pressure swing adsorption-desorption treatment to remove the impurities.

Process for purifying argon gas and apparatus used therefor

Nitrogen having purity of 99.9999% or more can be produced continuously by contacting a starting gas mixture comprising 90% by volume or more of nitrogen and 10% by volume or less of oxygen with A-type zeolite package in an adsorption column at an adsorption temperature of -100.degree. to -196.degree. C. to remove oxygen from the starting gas mixture and regenerating A-type zeolite by heating it at a temperature higher than the adsorption temperature.

Process for producing high purity nitrogen

Method and apparatus for separating gas mixture

A process and apparatus for recovering a high-purity inert gas by removing the impurities in a used inert gas (e.g., Ar), comprising a combustible component reaction step and reaction unit for adding oxygen to a raw gas containing a carbonaceous combustible component to thereby react the combustible component in said raw gas with the oxygen; a carbon dioxide gas removing step and removing unit for removing the carbon dioxide in the raw gas sent from said combustible component reaction unit; an oxygen reaction step and reaction unit for adding hydrogen to the raw gas after the carbon dioxide gas removal to react the oxygen remaining in said raw gas with the hydrogen; a moisture removing step and removing unit for removing the moisture in the raw gas sent from the oxygen reaction unit; and a refining step and refining unit for removing the remaining impurities from the raw gas after the moisture removal to recover a high-purity inert gas.

Process and apparatus for recovering inert gas

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Hitachi, Japan

Masaomi Tomomura