The cobalt cathode used in the EMS proved stable and efficient. Removal of H{sub 2}S was deterred by the possibility of hydrogen cross-over from process gases creating alternate reactions unfavorable to the removal system. Application of back pressure from the anode side of the cell would be the simplest solution to H{sub 2} cross-over. Examination of water proof of the vapor in the anode exit gases would provide proof of the aforementioned reaction hypothesis. Cobalt aluminate formation should not prove problematic, since degradation of the Co Cathode did not occur as a result. Once equilibrium is reached electrolyte addition is not necessary, therefore not a major concern.