PhD Oral Defense: Low Carbon Biomass Fuel Combustion and Ash Recycling for Sustainable Cement Production
PhD Oral Defense of Yu Wang, Natural Resource Sciences.
Switching to low carbon fuel (LCF) can help the cement industry reduce carbon dioxide (CO2) emissions effectively. This is because LCF generates energy that can lower the coal consumption in the kiln. Biomass fuel originating from perennial grass crops and woody materials is LCF that can be converted to clean energy (e.g. heat or steam) via combustion, which is an independent process from cement production. Meanwhile, the residual ash from the biomass combustion may be recycled by blending with cement if this ash possesses a high pozzolanic activity, which can reduce the demand for cement and accordingly lessen the CO2 emissions associated with cement production. Hence, the overall objectives of this thesis were to 1) investigate the combustion characteristics of switchgrass (Panicum vigratum L.) compared to hardwood; 2) characterize the physiochemical properties of switchgrass combustion ash, and assess the strength in mortars made from blended cement containing up to 20% switchgrass combustion ash content; 3) and optimize the combustion conditions to achieve a high energy conversion and ash pozzolanic value simultaneously.