CO2-CARBON GASIFICATION CATALYZED BY ALKALINE-EARTHS - COMPARATIVE-STUDY OF THE METAL-CARBON INTERACTION AND OF THE SPECIFIC ACTIVITY

The present work extends previous investigations about the calcium-cat alyzed carbon gasification to the case of strontium and barium with th e purpose of performing a comparative study of their catalytic activit y. This study also analyzes their intrinsic activity in order to under stand the working mechanism of these three catalysts. The results of i sothermal reaction in CO2 at different temperatures and TPD after CO2 contact at 573 K (or after a gasification experiment) have been used t o interpret the carbon gasification mechanism. The active species is t he carbonate and its decomposition at the interface produces the carbo n gasification. The analysis of TPD spectra after CO2 contact at 573 K allows us to determine the number of catalytic active sites and to co mpare, quantitatively (i.e., independently of the catalyst dispersion) , the specific activity of the three catalysts.