Large-scale production of anhydrous nitric acid and nitric acid solutions of dinitrogen pentoxide

摘要

A method and apparatus are disclosed for a large scale, electrochemical production of anhydrous nitric acid and N₂O₅. The method includes oxidizing a solution of N₂O₄/aqueous-HNO₃ at the anode, while reducing aqueous HNO₃ at the cathode, in a flow electrolyzer constructed of special materials. N₂O₄ is produced at the cathode and may be separated and recycled as a feedstock for use in the anolyte. The process is controlled by regulating the electrolysis current until the desired products are obtained. The chemical compositions of the anolyte and catholyte are monitored by measurement of the solution density and the concentrations of N₂O₄.