VOC emissions of coal-fired power plants in China based on life cycle assessment method

Abstract

During the coal-fired power generation process, both direct and indirect volatile organic compounds (VOCs) emissions are generated and emitted, releasing aerosols and particulate matter in the atmosphere. However, the indirect VOC emissions from coal-fired power plants (CFPPs) are often ignored, which causes considerable underestimation of total VOC emissions and their polluting effects on the atmosphere and human health. In this work, for the first time, the direct and indirect VOC emissions from coal-fired power generation processes are comprehensively assessed through life cycle assessment (LCA). Results show that the VOC emissions from coal mining, coal-fired power generation systems, flue gas cleaning systems, and waste disposal systems are estimated to be 2.31E−03 to 1.10E−02, 2.24E−03 to 1.46E−02, 2.38E−03 to 2.36E−03, 1.30E−05 to 1.33E−05 kg/MWh, respectively. The life cycle VOC emissions from the coal-fired power generation process as a whole are calculated as: 1.78E−02 to 9.85E−02 kg/MWh, without considering air pollution control devices' effects (APCDs). This value is reduced to 6.95E−03 to 2.80E−02 kg/MWh if the APCDs are implemented (61–72% reduction). Indirect emissions account for 48.46%–68.13% of life cycle VOC emissions, mainly from coal mining and flue treatment system. If considering all the CFPPs in China, the value of the total VOC emissions reaches at least 3.29E+04 t in 2017, while indirect emissions are up to 2.32E+04 t. The paper also analyzes the impact of the change of key input variables on the overall VOC emissions. Based on the results, proposing possible abating measures, which can be considered by authorities and decision-makers for promoting strategies to abate VOC emissions.