Influence of the Method of Preparation of Biochar from Peat and Sawdust on Its Composition and Thermal Characteristics

The influence of the temperature of hydrothermal carbonization and torrefaction on the properties of biochar obtained from sawdust and peat was studied. It was found that the yield of biochar decreased with temperature in both of the processes, whereas the degree of deoxygenation, the amount of carbon in the biochar, and its calorific value increased. In the course of the thermal treatment of biomass by both of the methods, hemicelluloses were completely destroyed and cellulose was partially degraded; as a result of this, lignin predominated in the biochar. At the same time, hydrothermal carbonization exerted a greater effect on the feedstock, as evidenced by a higher degree of cellulose destruction in the feedstock and by a higher calorific value of the resulting biochar.