Field Testing of a Continuous Real-Time In Situ SO_2/SO_3 Monitor

摘要

In an effort to provide real time in situ measurements of SO_3 in the flue gas from a coal-fired boiler, continuous analyzers for SO_3 and SO_2 using a quantum cascade laser (QCL) spectrometer were demonstrated. In situ measurements are felt to be potentially more accurate than extractive measurements in that they are not subject to biasing reactions that can occur during the transport of a flue gas sample in an extractive measurement monitor. The QCL systems were designed by IMACC for maximum energy throughput and unattended operation in an industrial setting. After testing and generation of quantitative SO_3/SO_2 spectral references in the lab, the first generation QCL system was installed on a 480 MW coal-fired boiler conducting coal test burns with different coal sulfur levels. The monitor was installed in a cross-duct (e.g. bistatic) configuration, with a separate transmitter and receiver module, for collection of continuous SO_3 and SO_2 emissions data during the month of November 2011. The second generation system design, a monostatic QCL spectrometer attached to an in situ sample cell that extends several feet into the flue gas duct, was installed for initial field testing on a 900 MW coal-fired boiler for collection of continuous SO_3 and SO_2 emissions data during the month of June 2012. Comparisons of the spectral resolutions, quantitative results and detection limits from the two system designs are presented herein.