Torrefaction is one of the thermochemical biomass conversion processes that has become popular due to its promising ability to improve the properties of biomass fuels, which can be carried out in oxidative an non-oxidative conditions. In this work, the torrefaction of pine sawdust and chlorella vulgaris biomass was studied at temperatures form 200 °C to 400 °C for 1 h, in batch mode, under oxidative and non-oxidative conditions. The yield of biochar produced, ash content, elemental composition and calorific value were determined in order to indicate the bahvior of these two different types of biomass under these two conditions. As a result, it was possible to conclude that temperature and the presence of oxygen have a determining influence on the properties of biomass, and that the presence of oxygen promotes an intensification of reactions during torrefaction.