Comparative Analysis of Coal and Biomass for Sustainable Energy Production: Elemental Composition, Combustion Behavior and Co-Firing Potential

This study offers a comprehensive comparative analysis of the elemental and proximate compositions of coal and biomass fuels, including Indo Coal, HBFL, SBP, and SBFL, highlighting their implications for sustainable energy production. Key elements such as aluminum, arsenic, boron, barium, calcium, chromium, copper, iron, potassium, lithium, magnesium, manganese, molybdenum, sodium, nickel, lead, antimony, silicon, and tin exhibit significant variations, emphasizing the importance of understanding each fuel source, particularly in co-firing applications. Combustion residues from these fuels show diverse elemental compositions, necessitating careful environmental management of elements like arsenic, lead, and chromium. Proximate analysis reveals distinctive characteristics, with variability in ash content affecting combustion efficiency and environmental considerations. The study finds that co-firing biomass with coal can significantly reduce NOx and SOx levels, with sulfur content in mixtures decreasing by up to 18%, leading to a potential 30% reduction in SO2 emissions. CO2 emissions could also be reduced by up to 51.21% as the biomass-to-coal ratio increases. Despite an 11% to 19% decrease in energy due to moisture imbalance, this can be optimized with technological advancements. Economic benefits are clear, as blending 2% of biomass can save 6.34% in both fuel consumption and purchase costs, with the highest cost-saving ratio of 72.87% achieved at a 20% blending ratio. Notably, most savings arise from the lower biomass purchase costs (Rs. 5000–6000 per ton) compared to coal (Rs. 15000–18000 per ton). However, technical challenges such as combustor fouling and corrosion from biomass ash must be addressed. Further research, particularly in thermal kinetic modeling, is recommended to examine the combustion characteristics of coal-biomass blends under controlled conditions. The progression from initial studies to long-term demonstrations indicates a promising future for co-firing technology, facilitating its widespread adoption in the industry at an optimal cost.