Fire Safety Science Digital Archive

This paper examines the chemisorption in air-preheated and nitrogen-heated wood chars that were created at heat treatment temperature as low as 140°C and 150°C and for extended preheating period up to 50 days that more closely resemble those encountered in built environment. The effect of chemisorption was examined in terms of consequent change in ignition temperatures and its correlation with the combustion behaviour. Chemisorption kinetics was studied using Elovich equation; gasification investigated by Arrhenius equation. A numerical analysis has been devised from Semenov model of thermal ignition to interpret the change in ignition temperature on the pyrolysis kinetics of wood chars and evaluate the kinetic significance of preheating duration and/or change in heat treatment temperature. This paper found that long-term air-preheated wood chars are capable of chemisorption, just as nitrogen-heated wood chars, ensued by ignition. Lower ignition temperatures have been noted in air-preheated samples. The change in ignition temperatures however is not thermally significant on the pyrolysis kinetics, as the Arrhenius parameters do not show a quantum leap to signify a change in pyrolysis pathways.