Gaseous and Particulate Chlorine Emissions From Typical Iron and Steel Industry in China. Issue 15 (7th August 2020)

• Record Type: Journal Article
• Authors: Ding, Xiang; Li, Qing; Wu, Di; Huo, Yaoqiang; Liang, Yingguang; Wang, Hongli; Zhang, Jie; Wang, Shuxiao; Wang, Tao; Ye, Xingnan; Chen, Jianmin
• Is Part Of: Journal of geophysical research. Volume 125:Issue 15(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-07
• Subjects: gaseous chlorine -- particulate chlorine -- chlorinated VOCs -- sintering -- FGD; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2020JD032729
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The accurate estimation of chlorine emissions is urgently needed to evaluate regional and global atmospheric chlorination. This study first reports on the gaseous/particulate phases of chlorine emissions from typical integrated steel industries, including the major manufacturing processes (i.e., sintering, ironmaking, and steelmaking) and self‐owned coal‐fired power plant (CFPP). The concentration of chlorine species emitted from the ironmaking/steelmaking processes and the self‐owned CFPP is very low (<1 mg/Nm 3 ). Owing to the combustion of chlorine‐rich sinter raw materials, the sintering processes emitted unexpectedly high concentrations of chlorinated substances, including chlorinated very short‐lived CH3 Cl, CH2 Cl2, C2 H5 Cl, and C2 H4 Cl2 . Flue gas desulfurization (FGD) systems equipped on the sintering processes can slightly reduce chlorinated hydrocarbons emissions (ClVOCs ). However, the chlorine species bonded in filterable/condensable particulate states (ClFPM /ClCPM ) can be removed by high efficient systems (with efficiencies of 64.8–94.1% for ClFPM and 97.3–98.5% for ClCPM ), relying on employed FGD technology. Owing to rapid rate at which FGD systems have been installed in China, ClInorganic gases, ClCPM, and ClFPM emissions from the sintering and iron industry in 2016 were reduced by 75.3%, 82.7%, and 45.6%, respectively. Our results indicate that the current ultralow‐emission equipment facilitates the reduction in chlorine emissions from iron and steel industry, but subsequent retrofits should give greater consideration to the simultaneous removal of ClVOCs . Plain Language Summary: A significant fraction of tropospheric chlorine atoms, inferred from midcontinental reactive nitrogen chemistry, may arise directly from anthropogenic pollutants. Particulate and gaseous chlorines, as important precursors of chlorine atoms, are mainly derived from anthropogenic combustion sources in polluted inland areas. The characteristics of chlorine emission from combustion sources in China mainly focus on coal and biomass combustion, most of which investigated the chlorine content in coal, raw materials, and by‐products according to mass conservation of chlorine; however, there are still very few field‐based studies on the chlorine emissions from industrial processes. Therefore, a full‐scale field study of chlorine emissions was conducted at typical iron and steel industrial processes in China including steel sintering, ironmaking, steelmaking, and self‐owned coal‐fired power plant. Owing to the combustion of chlorine‐rich raw materials, the steel and iron industry has emitted unexpectedly high concentrations of chlorinated substances. Flue gas samples (ClFPM, ClCPM, ClInorganic gases, and ClVOCs ) were collected from the inlets and outlets of the existing FGD systems to investigate their effects on speciation and distribution of the sintering flue gas, providing a scientific basis for the control and supervision of chlorine emission in the steel industry. Key Points: Sintering is identified to be an important emission source of chlorine species in filterable/condensable particulate and gaseous states Unexpected high concentrations of chlorinated very short‐lived CH3 Cl, CH2 Cl2, C2 H5 Cl, C2 H4 Cl2, and C2 H3 Cl are emitted from the sintering processes Removal efficiency, relying on FGD technology, is much higher for chlorine species contained in particles than that in gaseous states