| 摘要 |
PURPOSE:To suppress generation of methane in a disoxidation step and reduce a hydrocarbon concentration in products, by regulating the temperature of a disoxidation catalyst layer in a process for producing argon containing steps of adding hydrogen to crude argon gas and removing oxygen by catalytic reaction. CONSTITUTION:Air is successively introduced into main rectifying columns 2 and 3 to remove most of nitrogen and oxygen. The resultant air is then rectified in a crude argon column 4. The obtained crude argon gas containing a small quantity of oxygen and nitrogen is subsequently introduced into a disoxidation column 8 and hydrogen is added to initiate catalytic reaction. The contained oxygen is then converted into water and removed. Argon gas free of the oxygen is partially circulated through the crude argon gas before the disoxidation step to adjust the oxygen concentration in the crude argon gas. Thereby the temperature of the disoxidation catalyst layer in the disoxidation column 8 is kept at <=230 deg.C or adjusted to >=480 deg.C by a heater. The crude argon gas is then purified in a purified argon column 12 to afford the aimed product argon. |
