Electrolysis cell and method for electrolytic production of hydrogen

摘要

The production of hydrogen by electrolysis in a cell, in which the anode electrolyte contains sulfur dioxide as well as sulfuric acid and an intermediate chamber separated from the anode and cathode chambers by cation-exchanger membranes is provided through which an electrolyte flows in order to prevent sulfur dioxide from reaching the cathode chamber is greatly improved by using as the anode side membrane a cation-exchanger in which a polyvinyl chloride skeleton is combined with a polymer of styrol and divinyl benzol to which sulfonic acid groups have been attached, such a membrane having a very low resistivity, thus reducing the necessary electrolysis voltage. Such a membrane also loses conductivity with increasing sulfuric acid concentration at a lower rate than membranes previously used in such an electrolysis process and permits a higher sulfuric acid concentration in the anode electrolyte. The improvement on the anode side makes possible the operation of the cathode at low sulfuric acid electrolyte concentration, below 20 or even 10% by weight. Through-flow electrodes of porous graphite encased except on the membrane side by impermeable graphite further improve the operation of the process, especially if they fill the electrolyte chamber right up to the membrane.