CATALYTIC ACTIVITY OF POTASSIUM-SULFATE AND CHLORIDE SUPPORTED ON PEROVSKITE-TYPE OXIDE FOR THE GASIFICATION OF CARBON PARTICLES

Catalytic activities of potassium sulfate and chloride were studied fo r the combustion of activated carbon grains at 673-773 K by supporting the salts on the carbon or a perovskite type oxide (La0.8Sr0.2Cr0.5Mn 0.45Pt0.05O3, LSCMP). Both K2SO4 and KCl supported on LSCMP exhibited much higher activities than those supported on the carbon. Such salts supported on LSCMP liberated SO2 or Cl-2 during the carbon combustion reaction, and the temperatures for their decomposition were almost the same as the temperatures where carbon combustion started, Ln contrast , the salts supported on carbon hardly disintegrated under the present conditions. A part of the salts supported on LSCMP was found to be co nverted into K2CO3 after reaction as indicated by an IR nu(C-O) band a ssigned to K2CO3. Being observed in IR spectra, O-2 and LSCMP appear t o promote disintegration of K2SO4 and KCl in contact with carbon to ac tive species of either potassium metal or oxide in an early stage of t he carbon combustion. The active species can sublime to the carbon sur face and stay in the reaction zone by travelling between carbon and LS CMP during the catalytic combustion.