Patent · US Expired

Method and apparatus for making aqueous chlorine dioxide

US5855861A · kind A · utility

25Cited by
30References
31Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 23, 1996
Grant dateJan 5, 1999
Priority date
Expiry dateFeb 23, 2016

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC02F1/76
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

A method of forming an aqueous chlorine dioxide solution is disclosed which includes reacting in a reaction vessel an acid reaction solution containing a hydroxy carboxylic acid and a companion acid with an alkali metal salt of a chlorite ion. In accordance with the process, the hydroxy carboxylic acid serves to temporarily transfer chlorine from and does not form a salt with the alkali metal salt of a chlorite ion. The aqueous chlorine dioxide solution produced is substantially free of chlorous acid and preferably is free of other by-products such as sodium chloride and free chlorine. The method further includes maintaining the reaction vessel at a pH of less than 5 and/or withdrawing at least a portion of the chlorine dioxide from the aqueous chlorine dioxide solution. The method enables rapid, efficient, compact and safe generation of chlorine dioxide. A method of disinfecting water, and apparatus for making chlorine dioxide and for disinfecting water also are provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.