A technique for gas analysis based on pulsed-laser-induced photoacoustic spectroscopy in the UV and the visible is presented. The laser-based technique and the associated analysis probe have been developed for the analysis of pollutant chemistry in fluidized beds and other combustion environments with limited or no optical access. The photoacoustic-absorption spectrum of the analyzed gas is measured in a test cell located at the end of a tubular probe. This test cell is subject to the prevailing temperature and pressure in the combustion process. The instrument response has been calibrated for N2O, NO, NO2, NH3, SO2, and H2S at atmospheric pressure between 20 and 910 °C. The response of the probe was found to increase with pressure for N2O, NO, NH3, and NO2 up to 1.2 MPa pressure. The method and the probe have been used for detection and ranging of gas concentrations in a premixed methane flame. Some preliminary tests in a large 12-MW circulating bed boiler have also been done.
© 1995 Optical Society of America
Original Manuscript: November 28, 1994
Revised Manuscript: August 11, 1995
Published: December 20, 1995
Jari Stenberg, Rolf Hernberg, and Juha Vattulainen, "Analysis of pollutant chemistry in combustion by in situ pulsed photoacoustic laser diagnostics," Appl. Opt. 34, 8400-8408 (1995)