Four
fly ashes collected from electrostatic precipitators-three from municipal solid waste incinerators and one from a coal-fired power plant-were studied for their potential to catalyze carbon gasification reactions. A fixed-bed tubular reactor employing mixtures of oxygen and nitrogen was used to measure CO and COZ evolved from native carbon in fly ash in the temperature range 27S-350Β°C. Experiments using pure carbon were also run for comparison. MSWI fly ash was discovered to accelerate carbon gasification rates by at least an order of magnitude. At 3OO"C, gasification rates of native carbon in the different MSWI fly ash ranged from 1-8 mg-C/g-min, compared to pure carbon gasification rates of 0.03-0.2 mg-C/g-min. Activated carbon, having a high internal surface area, mixed to MSWI fly ash also showed an accelerated gasification rate, suggesting that the catalytic action was long-range. No catalytic activity was observed with coal fly ash. Apparent activation energies for gasification of native carbon in MSWI fly ash ranged from 25-34 kcalimole, while those for pure carbon ranged from IO-20 kcalimole. The apparent activation energy of gasification in coal fly ash was 14 kcalimole. The oxygen concentration dependence on gasification rate in fly ash was determined to be 0.54; that for pure carbon was 0.71.