Catalytic combustion of methane soot

The performances of a Cu-V-K catalyst in the oxidation of soot collected in a methane-rich flame have been studied in a tubular flow reactor. Burn-off temperatures were lowered by about 300 K with respect to uncatalyzed combustion. The dependence of the reaction rate on the relevant variables was investigated. The apparent activation energy for the catalytic oxidation was found to be about a half of the one of the uncatalyzed process, while the carbon reactivity showed a linear dependence on the initial soot to catalyst mass ratio. A square root dependence on the oxygen partial pressure was found. The results of soot combustion confirm previous findings obtained with other carbon materials. Moreover, kinetic data follow a model proposed for the catalytic combustion of amorphous carbon black (Ciambelli et al., 1994a). An extension of this model, incorporating the influence of carbon-catalyst contact on the catalyst performances, has been presented.