Note that the peak temperature of the cellulose volatilization and the upper temperature of lignin degradation were in a good agreement with reference data [21]. Switching the furnace medium from nitrogen to dry air had a rather weak influence on the behavior of the TG/DTG curves within the first three stages; however, the effects of furnace medium on the processes at high temperatures (>500 8C) were found to be significant. Compared to the pyrolysis, the first and second peak temperatures during the combustion test turned out to be slightly lower (by about 5 8C), whereas the biomass degradation rate at these temperatures was apparently higher (see Fig. 3).