Bibliometric Analysis on Mercury Emissions from Coal-fired Power Plants: A Systematic Review and Future Prospect

Abstract

Abstract Coal-fired power plants (CFPPs) are one of the most significant sources of mercury emissions certified by the Minamata Convention, which has attracted much attention in recent years. In this study, we used the Web of Science (WOS) and CiteSpace to analyze the knowledge structure of this field from 2000 to 2022 and then reviewed it systematically. The field of mercury emissions from coal-fired power plants has developed steadily. The research hotspots can be divided into three categories: 1) emission characterization research focused on speciation changes and emission calculations; 2) emission control research focused on control technologies; 3) environmental impact research focused on environmental pollution and health risk. In conclusion, using an oxygen-rich atmosphere for combustion and installing high-efficiency air pollution control devices (APCDs) helped to reduce the formation of Hg0. The average mercury removal rates of APCDs and modified adsorbents after ultra-low emission retrofit were distributed in the range of 82-93% and 41-100%, respectively. The risk level of mercury in combustion by-products was highest in desulfurization sludge (RAC>10%) and followed by fly ash(10<RAC<30%) and desulfurization gypsum(1<RAC<10%). Additionally, we found that the implementation of pollution and carbon reduction policies in China had reduced mercury emissions from CFPPs by 45% from 2007 to 2015, increased the efficiency of mercury removal from APCDs to a maximum of 96%, and reduced global transport and health risk of atmospheric mercury. The results conjunctively achieved by CiteSpace and the literature review will enhance understanding of CFPPs mercury emissions research and provide new perspectives for future research.