RATE OF REACTION OF CHLORINE DIOXIDE AND HYDROGEN-PEROXIDE

Because of environmental concerns about molecular chlorine, chlorine d ioxide is replacing chlorine in some important industrial applications . This situation has increased the interest in chlorine dioxide and ha s stimulated research related to its production. One process for manuf acturing chlorine dioxide involves reducing sodium chlorate with hydro gen peroxide. In this process, there is a side-reaction in which some chlorine dioxide is consumed by reaction with hydrogen peroxide. Initi al rates of this side-reaction were measured in a laboratory batch rea ctor. The side-reaction rate was compared with the rate that chlorine dioxide is produced under a typical set of industrial conditions: 80 d egrees C, 2 M sulfuric acid, 3.4 M sodium chlorate and 3.2 M sodium su lfate. To make this comparison, an empirical kinetic model of the side -reaction was developed from the experimental data. The reaction appro ximately follows first-order kinetics for chlorine dioxide and for hyd rogen peroxide; the activation energy is 12.4 kcal mol(-1). At the cit ed industrial conditions, the reaction model predicts that chlorine di oxide is consumed by the side-reaction at about 0.80/0-1.5% of the rat e at which it is produced.