CO2 and NO Reduction Characteristics from Biomass-Ammonia Co-firing in a Circulating Fluidized Bed Combustor

Since the adoption of the Paris Climate Agreement in 2015, the international community has been seeking to reduce greenhouse gas emissions and change to low-carbon economy to cope with climate change. Today, achieving carbon neutrality has become a common issue for energy technology development in the world. To reduce greenhouse gas emissions from coal-fired power plants, CO2 reduction technologies had been developed in three areas: efficiency improvement, CCUS, and fuel switching. However, the urgency of achieving carbon neutrality has prompted countries to phase out coal-fired power plants and related power companies are trying to switch coal into carbon-neutral or carbon-free fuels such as biomass and hydrogen including ammonia (NH3), respectively. NH3 has advantages in terms of energy transport and storage for hydrogen, and has been considered as a hydrogen carrier. In this study, the characteristics of NH3 co-firing with biomass were investigated in a 100 kWth circulating fluidized bed combustion test-rig. Operating temperature, pressure profiles and gas compositions with the NH3 co-firing ratio were measured at the range of 0–15.1%. From the experiment, it was shown that CO2 and NO generation could be reduced simultaneously by maintaining optimum condition for distributed feeding of NH3 to dense bed zone in the combustor.