Biomass torrefaction under different oxygen concentrations and its effect on the composition of the solid by-product

► Variations in oxygen concentrations during torrefaction influence very slightly the chemical composition of the wood. ► In relation with the oxygen concentration, the tendency was towards a reduction in the O/C and H/C ratios, with that tendency being more marked for the severest thermal treatment. ► The specific maximum weight loss rate can be used as a commonality parameter to evaluate the reactivity of torrefied biomass.