CATALYTIC COMBUSTION OF METHANE SOOT

The performances of a Cu-V-K catalyst in the oxidation of soot collect ed 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 un catalyzed combustion. The dependence of the reaction rate on the relev ant variables was investigated. The apparent activation energy for the catalytic oxidation was found to be about a half of the one of the un catalyzed process, while the carbon reactivity showed a linear depende nce on the initial soot to catalyst mass ratio. A square root dependen ce on the oxygen partial pressure was found. The results of soot combu stion confirm previous findings obtained with other carbon materials. Moreover, kinetic data follow a model proposed for the catalytic combu stion of amorphous carbon black (Ciambelli et al., 1994a). An extensio n of this model, incorporating the influence of carbon-catalyst contac t on the catalyst performances, has been presented.