Patent ID: 6200456
Filing Date: 2001-03-13
Classification: C25B

Abstract:
A process for the production of anhydrous nitric acid and a solution of dinitrogen pentoxide in nitric acid, and a concomitant process for producing solutions of dinitrogen tetroxide in nitric acid, the process comprising the steps of:a) providing a plate-and-frame, flow through, divided-cell type electrolyzer, said electrolyzer being provided with an anode disposed in an anode compartment and a cathode disposed in a cathode compartment, said anode and said cathode compartments being separated by a plurality of separators,b) placing a solution of N.sub.2 O.sub.4 in aqueous or anhydrous nitric acid in said anode compartment,c) placing aqueous or anhydrous nitric acid in said cathode compartment,d) applying a constant step-wise controlled current flow through said electrolyzer,e) vacuum distilling anhydrous N.sub.2 O.sub.4 formed in the catholyte,f) recycling said N.sub.2 O.sub.4 through said anode compartment as feed stock for said anode, andg) collecting anhydrous nitric acid and N.sub.2 O.sub.5 formed in said anode compartment.