Spatial and temporal dynamics of air-pollutant emission inventory of steel industry in China: A bottom-up approach

As one of the energy-intensive and high-polluted industries, steel industry is facing great challenges of energy saving and emission reduction. In this study, a bottom-up approach is used to build the inventory of air pollutants in China's steel industry. We analyzed the temporal and spatial characteristics of the atmospheric emission inventory of China's steel industry. The results show that: (1) In 2015, the total amount of SO2, NOx, PM, PM2.5, PM10 and PCDD/Fs emissions from Chinese steel industry were 1697.58kt, 1017.24kt, 4028.01kt, 849.02kt, 1330.53kt and 1216.83g I-TEQ, respectively. SO2, NOx, PM, PM10 and PCDD/Fs emissions mainly came from the sintering process, and PM2.5 came from the converter process. (2) NOx emissions show an "upward" trend, while SO2 emissions depict a "slowdown" trend. PM, PM2.5, PM10 and PCDD/Fs emissions present inverse U-shape trends. (3) The air pollutant inventory of Chinese steel industry indicates obviously spatial characteristics. Taking SO2 emissions in 2015 as an example, SO2 emissions from steel industry in North China and East China reached 1006.63kt, accounting for 65.2% of the total emissions. Hebei, Jiangsu and Shandong provinces where locate intensive traditional steel enterprises with majority of steel products generated SO2 emissions of approximately 404.04kt, 171.83kt and 156.28kt respectively, accounting for 23.80%, 10.12% and 9.20% total emissions of China's steel industry. (4) The simulation model of air pollutants (SO2, PM) was established taking adjusted production capacity and layout of steel industry into consideration, the simulation suggests that SO2 and PM emissions are projected to decrease by 1Mt, 2 Mt, respectively.