Abstract
The reduction of NO with NH3 and the oxidation of NH3 CO and H2 with O2 were investigated to establish the relations among gas composition, temperature, fractional conversion of each reactant and the reaction scheme in NO-NH3-CO-H 2-O2-H2O-N2 system. The experiments were carried out by using a flow reactor under an atmospheric pressure and at 550∼1050°C. The composition of inlet gas consisted of NO (0∼1000 ppm)-NH3 (0∼4000 ppm)-CO (0∼1%; mainly 1000 ppm)-H2 (0∼1%; mainly 1000 ppm)-O2(0∼5%; mainly 5%)-H20(0, 10%)-N2and the residence time was 0.37 Ns. The results obtained are summarized as follows.
1) Reaction temperature for both NO-reduction and NH3-oxidation was low ered by adding CO and H2; the higher CO and H2 concentration, the larger their effect. The effect of H2 was much superior to that of CO. The fractional conversion of NO showed a maximum at a certain temperature which depended on CO or H2 concentration, and the conversion of ca.80% was attained under coexistence of O2 of ca.1%, CO and H2. However, it was generally difficult to obtain the high conversion of NO by adding CO and H2.
2) The apparent oxidation rate of CO was remarkably promot ed under the coexistence of H20. Also, both oxidations of CO and H2 were considerably accelerated with NO, but wer e inhibited with NH3.
