A new method for the preparation of biomass-based solid fuels: Pyrolysis-impregnation-cobaking

As global climate change becomes increasingly severe, renewable energy sources must be identified. However, renewable biomass-based fuel suffers from high combustion rates and low heating values. To further optimise the performance of biomass-based fuels. In this work, a new biomass-based solid fuel with a low combustion rate and high heating value, i.e., biocoal, was prepared via pyrolysis–impregnation–cobaking using corn stover pellets and peanut seedling pellets as the raw materials. The combustion rate of this biomass-based solid fuel was effectively reduced, as evidenced by a decrease in the maximum mass loss rate of combustion, along with a shift of the mass loss peak towards the high temperature region. The higher heating value of this biocoal from peanut seedling pellets >20 MJ kg−1 (200 and 240 °C), about 5 % higher than biochar; therefore, use of biocoal instead of biomass in direct-fired biomass power plants promises to improve power generation efficiency. On the other hand, biocoal can also increase the proportion of biomass blended in coal-biomass hybrid power plants. Finally, the baking temperature of 200 °C was determined by considering the optimal heating value, combustion rate and yield of the biocoal, which can produce biocoal while meeting yield and heating value.