EFFECT OF CO2 ON CHARS PRODUCED FROM COAL AND BIOMASS AT HIGH HEATING RATES

Several papers showed that substitution of N2 with carbon dioxide has non-trivial effects on char combustion. Previous work showed that the reactivity and properties of chars can be affected by the peculiar conditions under which pyrolysis occurs in oxy-combustion systems. In the present work, pyrolysis experiments have been carried out in a laminar drop tube reactor on a high volatile bituminous Colombian coal and walnut shells in N2 and CO2 at a temperature of 1300 °C with high heating rates of approx. 3?104 °C/s. The reactivity of the resulting chars has been analyzed by TGA. Results are compared and discussed to highlight the effect of CO2 on char properties in relation to the different parent fuel.