Study On Hydrogen Cyanide In Modified Molecular Sieve And Alumina Purified Gas

Molecular sieve and γ-Al2O3were used as catalyst carrier in the experiments. Catalyst were prepared by excessive impregnation method. The effects of impregnation liquid concentration, roasting temperature and molecular sieve type were investigated. Based on the existing literatures and experimental phenomenon, we further optimize the reaction conditions and analyzed the dynamic process of the catalytic oxidation process. On the basis of catalytic reaction, we considered the effects of trace water. The results showed that the best concentration of Cu(NO3)2impregnation solution was0.1mol/L, the optimal calcination temperature was400℃when catalyst carrier was y-Al2O3. While the best concentration of Cu(NO3)2impregnation solution was0.2mol/L, and the optimal calcination temperature was300℃, when H-pmolecular sieve was used. Cu/H molecular sieve showed excellent performance above100℃, the conversion rate of HCN was above98%when the temperature reached200℃. While the initial reaction temperature of Cu/γ-Al2O3was150℃. The HCN conversion rate of Cu/Hβ molecular sieve changed little when oxygen volume fraction ranged from1%to5%. On the contrary Cu/γ-Al2O3was sensitivity to the oxygen volume fraction. The formation rate of NOX was less than5%between100-200℃, except when the temperature was200℃, and the oxygen volume fraction is higher than3%. In the experimental conditions the relation of the space velocity and HCN conversion rate agreed well with the experimental results. The influence of water vapour on HCN conversion rate could be neglected when the content was less than2%. The conversion rate of HCN and the production rate of NH3increased when the water vapor content reached2%.