SIMULTANEOUS REACTIONS OF CO, NO, O2 AND NH3 ON Pt/γA12O3 CATALYST IN A TUBULAR REACTOR

Abstract

Abstract A reliable method to continuously monitor NH3 in a gas stream containing CO—NO—O2 and H2O has been developed. The method is based on a quantitative oxidation of NH3 to NO on a Pt catalyst. The extent of this reaction is affected by temperature, excess oxygen present, and space-velocity. There is a significant effect of inlet O2 concentration on extent of various reactions in the CO—NO—O2—H2O system on a Pt/γAl2O3 catalyst. At fixed space-velocity and catalyst temperature, and for fixed reactor inlet concentrations of CO and NO. there is negligible CO—NO reaction either in the absence of oxygen or in the presence of excess oxygen. However, short of the stoichiometric amount of O2 required for CO oxidation, there is appreciable CO—NO (and possibly also CO—NO—H2O) reaction whose extent increases with increasing oxygen concentration. This increase is especially dramatic in a narrow window of O2: concentrations near the stoichiometric point. Interestingly enough, near the stoichiometric point, self-su...