Process for the preparation of sulfuric acid from sulphur dioxide

Abstract

In a process for the electrolytic production of sulfuric acid by oxidation of sulfur dioxide in the presence of water in an anode compartment of an electrolysis cell and of hydrogen in the cathode compartment of the cell, the cathode compartment containing aqueous sulfuric acid as catholyte and being separated from the anode compartment by a hydrogen-ion transfer permitting membrane, the improvement which comprises introducing sulfur dioxide, water and hydrogen iodide or iodine, removing a mixture of aqueous sulfuric acid and hydrogen iodide from the anode compartment, separating the sulfuric acid from the mixture, and removing from the cathode compartment the hydrogen set free therein. The process gives a substantially lower overvoltage than prior art processes.

Dependencies are inferred from the claim text.