LOW-TEMPERATURE REMOVAL OF HYDROGEN-SULFIDE FROM SOUR GAS AND ITS UTILIZATION FOR HYDROGEN AND SULFUR PRODUCTION

This investigation demonstrated the prospects for the development of c hemical-electrochemical plants for the removal of hydrogen sulfide fro m sour gas and production of high quality hydrogen and sulfur at low t emperatures. The anodic oxidation of sulfide ions, formed by scrubbing sour gas with sodium hydroxide and adjusting the pH of anolyte with m ore NaOH to a pH of nearly 14, produced polysulfide ions. In this cell the cathodic product was hydrogen, with the electrolyte in the cathod e chamber being NaOH. The electrolyte in the anodic and the cathodic c ompartments was separated by an ion exchange membrane (Nafion). The so dium polysulfide was transferred to a separate chamber through which s our gas, at a high concentration (10-15 vol.%) of H2S, was passed. Cry stalline sulfur was produced. The filtrate was mixed with the solution obtained by hydrogen sulfide scrubbing and returned to the electrolyt ic cell. Extremely pure hydrogen and sulfur were produced at a low cel l voltage (E(cell) = 1.0 V), and al a high current density (i = 300 mA cm(-2)).