Perpustakaan Digital ITB

Power generation activities rely heavily on the combustion of fossil fuels, leading to substantial greenhouse gas emissions. Among these fuels, coal is one of the most carbon-intensive. Numerous studies have been conducted to reduce CO2 emissions from coal-fired power plants, with non-carbon fuels being one of the proposed solutions. Ammonia (NH3) has recently gained attention as a promising alternative fuel, particularly through coal-NH3 co-firing technology, to mitigate CO2 emissions. Numerous studies on coal-NH3 co-firing have shown that implementing this technology in existing boilers can result in increased NO emissions. While these studies provide valuable insights, uncertainties remain regarding the performance of coal-NH3 co-firing in boilers specifically modified for ammonia co-firing. The objective of this study is to design a flue gas recirculation retrofit aimed at increasing the feasible NH3 co-firing ratio threshold while maintaining acceptable NO emission levels. The study was carried out using Computational Fluid Dynamics (CFD) simulations in Ansys Fluent, modeling coal-NH3 co-firing in a 350 MWe subcritical Carolina-type boiler with a tangential burner. This study found that applying flue gas recirculation (FGR) lowers the maximum temperature from 1393 oC at a 20% FGR ratio to 1297 oC at a 20% FGR ratio. It was also found that FGR utilization up to 20% could reduce NO concentration by up to 31% on coal-NH3 co-firing.