Life Cycle Assessment of Torrefied Residual Biomass Co-Firing in Coal-Fired Power Plants: Aspects of Carbon Dioxide Emission

This study investigates the carbon dioxide (CO2) emission characteristics of using torrefied biomass (residual wood and wood chip) as co-firing materials in coal-fired power plants, based on life cycle assessment techniques. We quantify the greenhouse gas (GHG) mitigation potential of substituting coal with biomass under different torrefaction temperatures, biomass types, and co-firing ratios. Results indicate that higher co-firing ratios significantly reduce CO2 emissions. Torrefaction at 270 °C was identified as optimal, balancing high energy yield and minimized emissions, while 310 °C torrefaction showed limited mitigation benefits due to lower mass yields and higher carbon content. Pelletization and torrefaction enhanced biomass properties, but the energy intensity of these processes affected the overall emission balance. This study underscores the potential of biomass to replace imported coal and contribute to carbon neutrality, while highlighting the importance of optimizing biomass processing conditions. Future work should focus on refining torrefaction parameters and assessing other biomass characteristics to enhance operational efficiency in coal-fired power plants. © 2024 by the authors.