Application of the biomass, oxyfuel and flameless combustion for the utilisation of pulverised coals for electricity generation (BOFCom) : final report

This project aimed to develop efficient, low-carbon options for coal use in coal-fired power plants by integrating three technologies: coal-biomass co-firing, oxyfuel and flameless combustion. A novel concept was developed by using: (a) lab-scale experiments to assess the behaviour of fuels and blends under oxyfuel conditions, (b) pilot scale tests to evaluate optimised configurations, and (c) mathematical models to study the application of the combined configuration for existing and new-build applications. The lab-scale tests assessed deposit formation phenomena using selected coals and biomass blends. The pilot-scale trials provided information on radiative and convective heat transfer and flame characteristics for different recirculation ratios, giving an indication of the likely behaviour of full-scale boilers. Finally, CFD simulations were used to assess the overall effect of retrofitting conventional full-scale power plants, making use of data generated in the experimental tasks. The results indicate clear changes in heat transfer patterns when retrofitting oxy-fuel technology, giving rise to specific implications for flame stability and ash deposition. These properties were measured for different coal and biomass fuels. The combination with flameless combustion gave an indication of the effects of mixing and the impact of high CO2 levels when designing retrofit and new-build installations. ASPENplus calculations demonstrated the increased possibilities of heat integration for retrofit boilers, due to the higher oxyfuel combustion temperatures and the increased cooling requirements of the air and CO2 compressors. Techno-economic studies compared the available state-of-the-art of the involved technologies and assessed the economic viability of the combined BOFCom concept.