Kinetic investigation on the smouldering combustion of boreal peat

Advanced knowledge of the mechanisms and kinetic parameters controlling the thermal decomposition of peat is of importance for understanding smouldering peat fires and quantify fire risk. Smouldering fires do not have the visual impact of the flaming front but constitute an important wildfire phenomenon because of the associated large carbon emissions and damage to a valuable ecosystem. Moreover, in case of extreme dry conditions or strong winds, smouldering fires develop easily into scrub or forest flaming fire. In this context, a thermal study on three different types of peat has been conducted: two high-moor peat types collected in Edinburgh (Scotland) and in Tomsk (Siberia), and one transition peat from Tomsk. The botanical composition, degree of decomposition and ultimate analysis were determined for the different samples and compared. These parameters were correlated to thermal behaviour obtained by Thermogravimetry experiments. Significantly different degradation behaviour is observed for the different peat types. A kinetic method to predict the temperature of the sample at high heating rates is applied. Comparison shows a good correlation between experimental and numerical results.