Volatile species release during torrefaction of biomass and its macromolecular constituents: Part 2 - Modeling study

Based on the torrefaction experiments carried out on beechwood and on its macromolecular constituents - cellulose, lignin and xylan - in part 1 of this paper, a simple torrefaction model was developed to predict both solid and the eight main volatile species yields versus temperature, residence time and biomass macromolecular composition. This model consisted in the superposition of kinetic “sub-models” describing the torrefaction of each constituent. The interactions observed in part 1 between constituents were then taken into account by means of an empirical factor related to cellulose decomposition rate. The model reproduced quite well the experiments and enabled to show the influence of each constituent on torrefaction yields.