Performance Modelling of Biomass/Ammonia/Coal Co-firing in Pulverized Coal-fired Boiler using Process Simulation

Abstract

Global pledges to reduce greenhouse gases (GHGs) emission have induced gradual reduction of coal utilization as fuel in power generation. Co-firing coal with carbon-neutral and carbon-free fuel such as biomass and ammonia offer an economically viable way to reduce carbon emissions. This study presents a thermodynamic analysis of biomass/ammonia/coal co-firing in 1,500 MW_th pulverized coal-fired boiler. The studied boiler is modelled using process simulation where equilibrium reactor is coupled with heat transfer equipment inside the boiler to approximate temperature and composition of flue gas. Base simulation case using pure coal as fuel is validated by comparing temperature and gas mass flow rate obtained from simulation with values reported in the datasheet of studied boiler. Fuel blends are varied while maintaining constant heat input and constant adiabatic flame temperature (AFT). The effect of co-firing ratio on flue gas temperature profile and GHGs reduction are visualized and discussed. Further analysis explores various fuel composition and identifies operating condition that exhibit lowest GHGs emissions. This study highlights the potential of biomass/ammonia/coal co-firing to reduce GHGs emission.