PROGRAM TOPIC: COMBUSTION DEVELOPMENT AND DEMONSTRATION OF LASER-INDUCED BREAKDOWN SPECTROSCOPY FOR IN-SITU, ON-LINE COAL ANALYSIS

Coal characterization and prediction of slagging behavior has reached great relevance for coal-fired power plant operators; especially, for units subject to large fuel quality variability, fuel switching and coal blending. Laser-Induced Breakdown Spectroscopy (LIBS) and Artificial Neural Networks were used in the development of an on-line system for in-situ coal characterization. The system consists of an excitation Nd:YAG laser, an Echelle spectrometer, a photodiode/amplifier unit, supporting optics and a processing computer, for above-the-coal belt applications. Demonstration of the system was carried out at PPL Generation’s Montour Power Station, to measure elemental composition of the plant coal supply, and the feedstock heating value and ash fusion temperature. A coal inventory composed of a range of twelve bituminous coals, fired at the station, was used to calibrate the system in the laboratory. The results demonstrated the capability of the LIBS technology to detect the following inorganic elements in real time: Al, C, Ca, K, Mg, Na, Fe, S, Si, and Ti. The measurement repeatability for heating value and initial deformation fusion temperature was within ± 76 Btu/lb and 33°F, respectively, for a range of heating values and fusion temperature from approximately 10,500-14,000 Btu/lb and 2,000-2,600°F,