Comparative Study To Evaluate the Drying Kinetics of Boreal Peats from Micro to Macro Scales

Peat is an organic and flammable material used for energy generation and involved in accidental wildfires. Smoldering combustion is governed by heterogeneous chemical reactions of drying and pyrolysis of the bulk solid and oxidation at the surface. In these phenomena, the drying process and its rate is an important mechanism. The aim of this research was to determine thermokinetic constants (TKCs) for the drying process at different scales for boreal peat samples from two regions and three depths. The drying experiments of various kinds of peat were mathematically described by two methods. To calculate the heat of water evaporation, inverse kinectic problems and the Kissinger-Akahira-Sunose method were used. For the determination of kinetic parameters, dynamic for micro scale and isothermal for macro scale experiments were conducted. The experimental data and corresponding TKCs for each peat type do not differ significantly from each other. This suggests that neither the scale nor the peat origin have a strong influence on the kinetics of the drying process.