Combustion of fly-ash carbon: Part II: Thermodynamic aspects and calorimetric experiment

Thermodynamic aspects of carbon combustion are discussed. At lower temperatures (<400°C), carbon dioxide is the dominant species in the reacting system. Thermodynamic calculations indicate that at low temperatures methane can be produced. Based on literature data, the reaction rate of methane generation is low and therefore the methane combustion represents probably only a marginal contribution to the overall energy balance. Calorimetric experiments proved that impregnation of pelletized carbon fly-ash samples by sodium and/or potassium carbonates have beneficial effect on conversion of CO to CO2. The value of the effective heat of combustion, calculated from CO and CO2 outlet concentrations, increased for sample modified by Na2CO3 by 5% and for sample modified with K2CO3 almost by 20%.