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

Torrefaction is a thermal treatment used to improve the properties of biomass in relation to thermo-chemical processing techniques for energy generation. It is a thermo-chemical treatment method primarily characterized by an operating temperature within the 200–300 °C range. It is carried out under conditions of atmospheric pressure and in the presence of a minimum amount of oxygen in order to avoid spontaneous combustion. The aim of this study was to evaluate the combined effect of the temperature (240 and 280 °C) and oxygen concentration (2, 6, 10 and 21%) on the physical and chemical properties of large particles of Eucalyptus grandis. A statistical analysis was carried out. The different oxygen concentrations did not significantly affect the composition of the solid by-product for low temperatures. At 280 °C, the high oxygen concentration affected some of the properties studied.