We investigate the thermochemical conversion of biomass in smouldering combustion by
combining experiments and modelling at two scales: matter (1 mg) and laboratory (100
g) scales. Emphasis is put on the effect of oxygen (0 to 33 vol.%) and oxidation reactions
because these are poorly studied in the literature in comparison to pyrolysis. The results are
obtained for peat as representative biomass supported by high-quality experimental data.
Three kinetic schemes are explored, including various steps of drying, pyrolysis and oxidation.
The kinetic parameters are found using the Kissinger-Genetic Algorithm method, and
then implemented in a 1D model of heat and mass transfer. The predictions are validated in
thermogravimetric and bench-scale experiments to unravel the role of heterogeneous reaction.
This is the first time that the influence of oxygen on biomass smouldering is explained
in terms of both chemistry and transport phenomena across scales.