Direct electrolysis of H_2S-loaded sodium carbonate solution

In order to restrain the anode passivation and increase the conversion ratio and current efficiency of sulfide to sulfur during the electrolysis of H2S-loaded sodium carbonate solution, direct electrolysis method by a filter press electrolyzer was used to recycle sulfur and hydrogen. Graphite was used as anode,and H2S-loaded sodium carbonate solution as anolytes;Titanium mesh was used as cathode and sodium hydroxide solution as catholytes. The effects of some parameters on anodic reactions were investigated,such as temperature,p H,initial concentration and current density. Results indicated that the conversion ratio of sulfide increased with the increase of initial sulfide concentration,but decreased with the increase of current density. Moreover,the appropriate electrolytic conditions were at temperature of 75℃,initial sulfide concentration above 0.5mol/L,current density of 10—20m A/cm2,and no sodium hydroxide addition into anolytes. Under the above conditions,the conversion ratio of sulfide could exceed 85%. The characterization of recovered sulfur with XRD and SEM methods showed that the produced sulfur was rhombi with bigger particle diameter,which was favorable in solid-liquid separation.