What are continuious Emission monitoring systems?
A Continuous Emissions Monitoring System, or CEMS, in the application of a power plant is a system that draws flue gas from a point in the gas path, conditions it, and sends it through analyzers. Generally these would be Carbon Monoxide, Oxygen, Oxides of Nitrogen (NOx), and Oxides of Sulfer (SOx). Possibly Carbon Dioxide, depending on the requirements of the authority having jurisdiction over air quality. These analyzers provide real time data (minus delay time for gas transit) to the operators, and to a data collection system for archiving and reporting. For a coal plant mercury is one of the major items of concern in the final flue gas. Some plants have CEMS units to test the flue gas prior to any flue gas treatment devices such as cyclone seperators, electrostatic precipitators, bag houses, and scrubbers. Mostly it’s the final CEMS data that is most important and the other one would confirm the efficiency of the flue gas treatment devices. Wet chemistry of waste streams would be to
