METHOD FOR ADSORPTION AT VERY LOW TEMPERATURE FOR GENERATING ULTRA-HIGH PURITY NITROGEN

摘要

PROBLEM TO BE SOLVED: To generate effectively ultra-high purity nitrogen without substantially containing hydrogen, oxygen and carbon monoxide by a method wherein nitrogen gas containing at least one kind in impurities of hydrogen, oxygen and carbon monoxide is brought in contact with a metal-containing adsorbing material at a specific temperature. SOLUTION: A nitrogen vapor flow to be treated is allowed to flow in a very low temperature refining apparatus 12 through a pipe line 11, and hydrogen, carbon monoxide and their residual oxygen are removed therein. The refined product flow flowing out through a pipe line 13 from the refining apparatus 12 is then allowed to pass through a heat exchanger 5, and recovered after warming to an environmental temperature. The refining apparatus 12 comprises two adsorbing material floors i.e., refining floors 12A, 12B, each refining floor 12A, 12B houses a metal-containing adsorbing material wherein at least 5%, preferably 10 to 30% of nickel is contained, and the residue is allowed to be an alumina adsorbing material. The nitrogen vapor flow is brought in contact with the metal-containing adsorbing material at a temperature of under 150 deg.K with the refining apparatus 12 to eliminate hydrogen, oxygen and carbon monoxide.