Mechanism explanation for SO2 oxidation rate of Cs-Rb-V series sulfuric acid catalyst at low temperature
摘要
The reaction kinetics of SO2 oxidation on Cs-Rb-V series sulfuric acid catalyst promoted by alkali salts such as cesium and rubidium was studied. A three-step reaction mechanism of SO2 oxidation was proposed, in which it was assumed that oxidation of quadrivalent vanadium complex was a controlling step. Then, a mechanism model equation was concluded according to the three-step reaction mechanism. The SO2 oxidation rate was measured with a non-gradient reactor under the conditions of temperature of 380～520 ℃ and space velocity of 3 600～7 200 h-1. Through calculating with Powell nonlinear regression method, the parameters of model equation were obtained: K1=0.152 exp(-62 073/(RT)), K2=8.18 exp(-2 384/(RT)), K3=0.221 exp(-18 949/(RT)). It was found that the model equation could fit with all the experimental reaction rate data very well.