Research Progress on Volatile Organic Compounds Emissions from Coal-fired Power Plants

Known as the high-priority air pollutants in the atmosphere, volatile organic compounds (VOCs) are a dominated precursor of secondary organic aerosols (SOAs), leading to complex PM2.5 and O-3 pollution and severe risks to human health. Considering upward concentrations of VOCs emitted from a great number of coal-fired power plants in China, considerable contributions of this primary source to current air pollution remain to be addressed. Previous studies have underestimated the concentration level of VOCs emissions from actual coal-fired power plants, largely because of incomplete monitored species, inconsistent results of emission characteristics and unclear effectiveness of VOCs removal by current flue gas purification units. Herein, recent progress on the field measurement techniques, pollution characteristics of VOCs (i.e., concentrations, chemical speciation and transformation) and impacts of flue gas purifying technologies on the VOCs control in coal-fired power plants were reviewed. In addition, key research perspectives in the future are proposed to formulate the technical standards for precise monitoring of VOCs from coal-fired power plants. The optimal combustion conditions under low-load operation conditions are to be determined. The ideal synergistic control strategies of VOCs emissions are anticipated to work out. As such, this review will provide some new insights into the development and formulation of VOCs control technologies in coal-fired power plants for the air quality improvement in China.