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.

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.

An argon gas recovering and purifying method including: introducing waste argon gas containing nitrogen, oxygen, and carbon monoxide from silicon single crystal manufacturing apparatus into waste argon gas storage tank; removing solid matters in pretreatment facility which removes the solid matters in waste argon gas; converting oxygen into water and converting carbon monoxide into carbon dioxide by catalytic reaction; removing the water, the carbon dioxide, and the nitrogen to obtain recovered gas, in the argon gas recovering and purifying method and an argon gas recovering and purifying apparatus, the catalytic reaction is carried out with compression heat alone by arranging a catalyst in a two-stage compressor, and the water is removed by a dryer in advance and then the nitrogen and the carbon dioxide are adsorbed and removed in an ordinary-temperature adsorption tower at the step of obtaining the recovered gas.