Halogen Emissions from Coal-Fired Power Plants in China: Evolutions, Driving Forces, and Future Trends

Atmospheric halogens, including fluorine (F), chlorine (Cl), bromine (Br), and iodine(I), significantly impact atmospheric chemistry and climate change. Containing all types of halogens, coal fired power plants (CFPPs) are among the major anthropogenic sources of atmospheric halogens. However, comprehensive estimates of halogen emissions from CFPPs in China remain limited, despite significant advancements in scale and pollution control. This study developed a detailed emissions inventory for all halogens from CFPPs using multisource data and the mass balance method, analyzing their spatiotemporal variations, driving forces, and future trends under climate goals. Results showed fluctuating halogen emissions from 2018 to 2022, with F, Cl, Br, and I reaching 6,875.7 t, 24,872.4 t, 1,127.9 t, and 476.7 t in 2022, respectively. Emissions were predominately concentrated in key coal resource areas and high-energy-consuming regions. Increased coal consumption was the primary driver of emissions growth, while improvements in pollution control and power generation technology contributed to reductions. Under air pollution control and climate goals, halogen emissions are expected to peak before 2030 and decline rapidly thereafter, with near-elimination by 2050. Combining strict air pollutants and carbon control technologies would offer the greatest reduction potential.