METHOD FOR PRODUCING GLYOXYLIC ACID BY ELECTROREDUCTION WITH CATHODIC REACTIVATION OF OXALIC ACID

摘要

Method for producing glyoxylic acid by electroreduction, with cathodic reactivation, of oxalic acid in a divided eletrolytic cell comprised of an anodic compartment formed of an anode and an aqueous solution of a strong mineral acid as anolite and of a cathodic compartment formed of a lead cathod and an aqueous solution saturated with oxalic acid, the two compartments being separated by a cationic exchange membrane. The method comprises the addition of Pb(II) salts to the catholite or to the anolite in order to keep at high and constant levels throughout the operation both the current efficiency and the selectivity of the process. The effect of Pb (II) salts may be potentiated by washing the cathode with nitric acid. The glyoxylic acid is an intermediary in the industrial synthesis of p-hydroxyphenylglycine and vanillin, inter alia.