The measurement of SO2 in power station plumes with differential lidar

Abstract

The use of differential lidar for measuring SO2 in plumes from fossil fuelled power stations is examined. The potential of the technique is investigated for the measurement of SO2 close to power station stacks and in situations where the long range transport of emissions is important. Detection limits are discussed as a function of range and spatial resolution and it is shown theoretically that concentrations as low as 10 ppb at a range of 2 km should be measurable. Details of a prototype, computer controlled, differential lidar based on a tunable dye laser are given and its mode of operation described. Results from field experiments carried out at Drax power station in Yorkshire (UK) and Fawley Power Station in Hampshire (UK) are presented. For plumes of small diameter a deconvolution technique has been applied to obtain better spatial resolution of the plume structure.