Abstract: A vacuum operated electrolytic generator can be used to produce a chlorine dioxide solution or a mist of chlorine dioxide from a buffered aqueous alkali metal chlorite solution in one pass through an electrolytic cell. The cell contains a high surface area anode, a corrosion-resistant highly conductive cathode, and a cation ion exchange membrane between the anode and cathode. An eductor is used on the anolyte effluent line to create a vacuum and draw the anolyte through the cell. Either motive water or a motive inert gas (such as air) is used in the eductor. Preferably, an eductor is used in the catholyte effluent line. An ascending anolyte effluent line with a non-corrosive check valve leads from the cell to the anode eductor. Sensors are used to monitor the composition of the anolyte effluent and/or the anolyte feed. The final product is a chlorine dioxide solution when water is used for the eduction.

Abstract: Provided is a process for the preparation of chlorine dioxide. The process comprises separately feeding compounds, which when reacted together yield chlorine dioxide, into a diluting water stream. The compounds react to thereby form chlorine dioxide. Shutoff valves are provided in the feed lines of the compounds, which shutoff valves are in cooperation with a supply monitoring system and a pH meter. The supply monitoring system monitors the feed lines of the compounds and the water stream. When the monitoring detects a loss in the supply of the water or one of the compounds, shutoff valves are closed to restrict any further flow of the compounds through the feed lines. The pH meter is located downstream of the reaction and monitors the pH of the chlorine dioxide solution formed by the reaction. When the pH is detected to be outside of a particular range, the shutoff valve are closed to restrict any further flow of the compounds through the feed lines.

Abstract: Provided is a process for preparing a gaseous stream of chlorine dioxide. The process comprises first providing an aqueous stream of chlorine dioxide. The chlorine dioxide stream can be provided, for example, by reacting an alkali metal chlorite such as sodium chlorite with an alkali metal hypochlorite such as sodium hypochlorite and an inorganic acid such as hydrochloric acid, or by reacting chlorine gas and an alkali metal chlorite such as sodium chlorite. The resulting aqueous stream is then contacted in countercurrent fashion with a stream of inert gas or air, resulting in chlorine dioxide being stripped from the aqueous stream. A chlorine dioxide containing gaseous stream is then recovered, which is suitable for further use. The process thereby safely and efficiently generates a gaseous stream of chlorine dioxide for subsequent use.