THE EFFECTS OF ION-EXCHANGED COBALT CATALYSTS ON THE GASIFICATION OF WOOD CHARS IN CARBON-DIOXIDE

The high catalytic activity of cobalt in gasification of wood chars by carbon dioxide has been studied by determining the effect of heat treatment temperature (HTT) on reactivity of the char and the chemical state of the catalyst. The pyrolytic transformations occurring as low-temperature chars (HTT 400 degree C) are heated to higher gasification temperatures have also been studied in order to determine first, the nature of the interaction of the catalyst with the pyrolytic carbon; and second, the type of gases produced by pyrolytic reactions prior to or during gasification by carbon dioxide. Maximum catalytic activity was not observed until the HTT exceeded 600 degree C. The maximum rate of gasification was not strongly dependent on HTT, but as the HTT was increased the duration of the maximum level of reactivity was reduced, and an increasingly smaller fraction of the carbon maintained contact with the catalyst.