Boilers involve ∼60% of primary energy consumption
in China
and emit more air pollutants and CO2 than any other infrastructures.
Here, we established a nationwide, facility-level emission data set
considering over 185,000 active boilers in China by fusing multiple
data sources and jointly using various technical means. The emission
uncertainties and spatial allocations were significantly improved.
We found that coal-fired power plant boilers were not the most emission-intensive
boilers with regard to SO2, NOx, PM, and mercury but emitted the highest CO2. However,
biomass- and municipal waste-fired combustion, regarded as zero-carbon
technologies, emitted a large fraction of SO2, NOx, and PM. Future biomass or municipal waste mixing
in coal-fired power plant boilers can make full use of the advantages
of zero-carbon fuel and the pollution control devices of coal-fired
power plants. We identified small-size boilers, medium-size boilers
using circulating fluidized bed boilers, and large-size boilers located
in China’s coal mine bases as the main high emitters. Future
focuses on high-emitter control can substantially mitigate the emissions
of SO2 by 66%, NOx by 49%,
PM by 90%, mercury by 51%, and CO2 by 46% at the most.
Our study sheds light on other countries wishing to reduce their energy-related
emissions and thus the related impacts on humans, ecosystems, and
climates.