Continuous emission monitoring systems at power plants in China: Improving SO2 emission measurement

The Chinese Government recently mandated the installation of continuous emission monitoring systems (CEMS) at state-controlled key polluting facilities in order to provide direct, real-time, continuous measurements of sulfur dioxide (SO2) emissions. By 2010, most coal-fired power plants in China have installed and are operating SO2 CEMS. As China's Central Government strengthens the SO2 control program and implements new nitrogen oxides (NOX) and carbon dioxide (CO2) control programs, the quality of and confidence in CEMS data will become more important. This study utilizes field surveys and existing literature on Chinese CEMS to analyze their operation and management. Our study found that the Chinese government has issued a set of regulations and technical guidance documents to standardize CEMS operation, management, and supervision, and to improve the quality of CEMS data. Many power plants have followed key parts of the national CEMS rules and guidance and are periodically inspected by local environmental authorities. This study suggests several options for addressing some of the gaps and problems with the CEMS operation and supervision and thus enhancing China's CEMS program.

► Nearly all coal power plants in China have SO2 CEMS providing direct, real-time, continuous measurements of emissions.
► Government and industry have made significant progress toward a comprehensive measurement system.
► We found that problems remain and CEMS operation and supervision is inconsistent.
► Data from power plant CEMS often undergo limited quality assurance and analysis.
► We propose some options for enhancing the CEMS network.