Patent ID: 6576213
Filing Date: 2003-06-10
Classification: C01B

Abstract:
A continuous method of producing chlorine dioxide comprising the steps of (a) providing a reactor with an aqueous acidic reaction medium containing chlorate ions; (b) continuously adding to the reaction medium hydrogen peroxide stabilized with a stabilizer selected from the group consisting of 1-hydroxy-ethylidene-1,1-diphosphonic acid, 1-aminoethane-1,1-diphosphonic acid, aminotri(methylenephosphonic acid), ethylene diamine tetra(methylenephosphonic acid), hexamethylene diamine tetra(methylenephosphonic acid), diethylenetriamine penta(methylenephosphonic acid), diethylenetriamine hexa(methylenephosphonic acid), salts thereof and mixtures thereof, said stabilized hydrogen peroxide containing less than about 20 mg Sn per kg hydrogen peroxide; (c) reacting said chlorate ions with hydrogen peroxide as a reducing agent in such proportions that chlorine dioxide is formed; and (d) withdrawing chlorine dioxide from the reaction medium, wherein the hydrogen peroxide continuously added to the reaction medium is substantially free from tin or tin compounds or contains less than about 15 mg Sn per kg H2O2.