Quantitative Spectrographic Analysis for in Situ Continuous Emission Monitoring

Abstract

To determine the thermal efficiency and the effluent flow rates of fossil-fired boilers, Exergetic Systems has developed an in situ, dispersive interferometer. This Emissions Spectral Radiometer/Fuel Flow instrument (ESR/FF) can measure effluent concentrations with the high accuracies needed to make efficiency determinations and to meet environmental control requirements. This paper discusses the software algorithms developed to process the data from these instruments to provide accurate peak-to-peak normalization of measured absorbance data to HITRAN-generated data. After implementation of both signal-domain and frequency-domain normalization, the frequency-domain method was chosen because it was significantly faster to process. With the use of this analysis method and the pre-installation calibration method described herein, flue gas compounds are quantified with a sensitivity of 10 Δppm. This inexpensive and reliable instrument yields accurate quantitative analysis of flue gases for continuous emission monitoring (CEM) of fossil-fired boilers.