PREPARATION PROCESS OF METHANOL-BASED CHLORO DIOXIDE

摘要

ClO2 is produced efficiently by the redn. of NaClO3 in an aq. medium. The reaction is carried out at the b.pt. under reduced pressure. Pref. HClO3 and HCl react with consumption of Cl- and formation of HClO, which is reduced to Cl- by MeOH. If HClO is produced more quickly than it is consumed, it reacts with HCl to form Cl2. This hampers prodn. of ClO2 and also contaminates the prod.. Lower acidity with higher ClO3- concn. controls the rate of HClO formation. The concn. of acid (H2SO4) is below 7 N (above 5 N) and that of ClO3- is 2-6 (2.5-4) M. Partic. concns. used are mutually dependent. NaHSO4.Na2SO4 is obtd. as a by-prod.. MeOH consumption is approx. 0.2 (0.13-0.16) tons per ton of ClO2 produced; the latter is admixed with steam. The efficiency of ClO2 prodn. is at least 90% (exceeds 95%).