Patent ID: 6010675
Filing Date: 2000-01-04
Classification: B01D,C01B,C10K,H01M,Y02E

Abstract:
A method of reducing to a desired minimum level the concentration of carbon monoxide in a gaseous medium that also contains at least hydrogen, by selective catalytic oxidation in the presence of gaseous oxygen using a catalyst which is capable of oxidizing carbon monoxide in an exothermic reaction at temperatures within a given temperature range, but is rapidly inactivated when exposed to high carbon monoxide concentrations at less than a threshold temperature within the given temperature range, and incapable of reducing the carbon monoxide concentration to the minimum level when exposed to carbon monoxide at above the threshold temperature, comprising the steps ofconfining a quantity of the catalyst;passing the gaseous medium through the confined catalyst quantity from an inlet portion to an outlet portion thereof;introducing gaseous oxygen into at least the inlet portion of the confined catalyst quantity; andcontrolling the temperatures encountered in the confined catalyst quantity in such a manner that the exothermic reaction takes place initially at above the threshold temperature in the inlet portion and subsequently at below the same threshold temperature in the outlet portion.