Heat integration of biomass co-firing in coal power plant

Carbon dioxide from combustion of fossil is the major source of greenhouse gas emissions, which has recently been vigorously regulated worldwide. Oxy-coal combustion with carbon dioxide capture and sequestration (CCS) is among the promising clean coal technologies for reduction of CO₂ emission. However, the efficiency of an oxy-coal plant is significantly lower than that of air-combustion counterpart due to energy penalties from air separation and CO₂ compressor units. Concerning CO₂ emission, oxy-co-combustion with biomass induces the CO₂ reduction. For comparisons purposes, the study also evaluates the combustion impact on coal blending with biomass. To compensate the energy loss, pressurized combustion and heat integration framework are introduced in a 100 MWe-scale power plant constructed by Aspen Plus in this study. The results demonstrate that more thermal energy is retrieved from high-density gas at elevated pressure by increasing the temperature of waste flue gas and reducing the amount of steam extracted from the turbines. With heat integration configuration, the heat source from coal combustion is completely utilized to achieve higher efficiency.