High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly progress report, October 1, 1996--December 31, 1996

An advanced process for the separation of hydrogen sulfide H{sub 2}S from coal gasification product streams through an electrochemical membrane is developed using funds from this grant. H{sub 2}S is removed from the syngas stream, split into hydrogen, which enriches the exiting syngas, and sulfur, which is condensed from an inert sweep gas stream. The process allows removal of H{sub 2}S without cooling the gas stream and with negligible pressure loss through the separator. The process is made economically attractive by the lack of need of a Claus process for sulfur recovery. To this extent the project presents a novel concept for improving utilization of coal for more efficient power generation. This quarter focused on replacing the MACOR cell housings with stainless steel, which is more industrially suitable. Three runs were attempted this quarter, with successful results achieved in Run 34. The purpose of these experiments was: (1) test the electrochemical membrane separator`s ability to concentrate CO{sub 2}, (2) test the electrochemical membrane separator`s ability to remove H{sub 2}S; and (3) test stainless steel as an alternative cell housing to MACOR as well as test nickel cathode performance at the reduced temperature