Impact of Heating Modes on Thermochemical Behavior of Wood Pyrolysis Process

Abstract Pyrolysis is a thermal decomposition process occurring without oxygen, producing liquid oil, gases, and biochar from biomass. The key factor controlling pyrolysis is the thermal energy supplied intensity to the biomass. This study investigates the impact of heating boundary conditions on biomass pyrolysis through a mathematical model incorporating mass and energy conservation, solved numerically using the volume element method. The model is validated against experimental temperature data from a single spherical wood particle under convective heating. It is then applied to a sawdust layer under two conductive heating modes: constant temperature and insulated boundary. Results show that constant temperature heating accelerates pyrolysis threefold and increases tar and gas yields, whereas insulation slows heat transfer, delaying temperature stabilization but producing denser, higher yield char. These findings emphasize the importance of boundary conditions in optimizing biomass conversion.