We demonstrate a high-sensitivity laser-based spectrometer for simultaneous detection of sulphur dioxide (SO2) sulphur trioxide (SO3) and water for coal-fired combustion applications. The spectrometer is based on a quantum-cascade laser (QCL) operating at 7.16 μm, capable of measuring all three components simultaneously in a single frequency sweep. An optical multipass cell having a total path length of 9.1 m is used at increased temperature and at low pressure to ensure reliable measurement of highly reactive SO3 and adequate separation of overlapping spectral features, respectively. Detection limits for SO2 and SO3 are 0.134 and 0.0073 ppm, respectively, when employing a 20-s sampling time.
|Journal||Applied Physics B: Lasers and Optics|
|Publication status||Published - 1 Jan 2014|
|MoE publication type||A1 Journal article-refereed|