Simultaneous detection of nickel and potassium in the flue gas of a fluidised bed coal combustor by excimer laser-induced fragmentation fluorescence

Abstract

Photofragmentation fluorescence is now well known as a sensitive, real-time technique for detection of metals and other species of environmental and industrial interest. This work aims to demonstrate the feasibility of real-time monitoring of nickel species in a realistic industrial flue gas using excimer laser-induced fragmentation fluorescence (ELIF), but at the same time, potassium species were monitored in a second detection channel. An ArF-excimer laser (193 nm) was used for photofragmentation and the fluorescence of Ni and K atom fragments was detected at 440 and 769 nm, respectively. Actual flue gas measurements were performed at the atmospheric pressure fluidised bed combustor (FBC) of DMT and first observations of the behaviour of these two species under flue gas conditions were made. Results suggest that the release of both metal species is affected by both the amount of chlorine and by the amount of clay minerals in the system. Estimating from present signal–noise levels, a sensitivity of ca. 50 ppb is achievable for Ni at the present wavelength.