The Dow Chemical Company

Mou S Chao

Kenneth J Stutts

Indresh Mathur

Richard D Varjian

Gale G Hoyer

Ramanathan Gopal

Michael E Paulaitis

A method of producing sodium dithionite comprising electrolyzing a catholyte solution of sulfur dioxide in an electrolytic cell at a pH of at least about 3, the electrolytic cell having a carbonaceous cathode, is disclosed. Particularly high current efficiencies can be attained using a high surface area carbon material for the cathode. The use of a stabilizer to inhibit decomposition of the sodium dithionite to form sodium thiosulfate is also disclosed. The stabilizer is added to the catholyte and is selected from the group consisting of phosphoric acid, sodium tripolyphosphate, acid phosphates and mixtures thereof.

Method of producing sodium dithionite by electrochemical means

The invention is a method for operating an electrochemical cell of the type having an anode and a cathode which are in contact with an aqueous electrolyte in the presence of at least one electroactive species, said method comprising: electrochemically converting at least a portion of at least one electroactive species to at least one electrochemical product while maintaining said aqueous electrolyte at supercritical fluid conditions.

Electrochemical cell operating near the critical point of water

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Midland, MI, United States of America

Mou S Chao