Analysis of emission characteristics and driving forces of air pollutants and GHG from coal-fired industrial boilers in China

Coal burning is considered to be the main anthropogenic source of air pollutants, which can cause serious environmental pollution. As one of the important coal burning sources, coal-fired boilers have become the important challenges of the policy of "carbon peaking" and "carbon neutrality" of Chinese government. In this paper, the emission inventory of air pollutants (TSP, SO2, NOX, VOCs), and greenhouse gases (GHG, including CO2, CH4, N2O) from coal-fired industrial boilers (CFIB) from 2006 to 2020 are established by using the "bottomup" emission factor method. Besides, Kaya identical equation and Logarithmic mean Divisia index (LMDI) model are used to quantify the driving forces of the changing tendency in pollutants emission based on five driving factors, which include pollution production coefficient (f), control technology level (beta), economy (GOV), industrial energy intensity (e) and coal consumption structure of industrial boilers (s). Combined with existing relevant policies, the future emission tendency of air pollutants and GHG in 2025 and 2030 is projected. The result shows that policy adjustment has a significant impact on pollutant emission trends. In 2020, emissions of TSP, SO2, NOX, VOCs and GHG from CFIB in China are 679.5 kt, 644.7 kt, 603.9 kt, 40.7 kt and 4.4 x 105 kt CO2e, respectively. Control technology level is the main factor to the emission reduction of SO2 and TSP, which has caused a decrease of 4278.6 kt and 3337.3 kt in emissions of SO2 and TSP compared to those of 2006 respectively, while the influencing effect on NOX, GHG and VOCs was relatively weak. In addition, in the scenario of improved control technology, pollutant emissions could be reduced by 62.6%-94.9% until 2030.