Impact of biomass diversity on torrefaction: Study of solid conversion and volatile species formation through an innovative TGA-GC/MS apparatus

Abstract

The objective of this work is to compare the kinetic behavior of a large set of European biomasses during torrefaction, both in terms of solid transformed and volatile species released, and to determine whether biomass behaviors can be classified according to main biomass families, namely deciduous wood, coniferous wood, agricultural coproducts and herbaceous crops. 14 biomasses representative of European diversity were torrefied in chemical regime following a non-isothermal procedure (200 to 300 °C, 3 °C min-1) in a thermogravimetric analyzer coupled with a gas-chromatograph mass spectrometer through a system of heated storage loops (TGA-GC/MS). Coniferous and deciduous wood were found to have similar behaviors in terms of solid evolution profile and species produced, while being different in terms of kinetics. On the contrary, agricultural biomass appeared to be a highly heterogeneous group where different biomass subtypes should be selected in order to represent the diversity of behaviors during torrefaction. Biomass macromolecular composition, together with the biological origin and the structural matrix of biomass, were shown to be determining factors of biomass behavior in torrefaction.