Quantitative Remote Sensing of Sulfur Dioxide Emissions from Industrial Plants Using Passive Fourier Transform Infrared (FTIR) Spectroscopy

The remote monitoring and quantification of industrial gas emissions, such as sulfur dioxide (SO\( _2 \)), are critical for environmental protection. This research demonstrates the application of passive Fourier Transform Infrared (FTIR) spectroscopy for the remote detection and quantitative analysis of SO\( _2 \) emissions from a metallurgical plant chimney. Infrared spectra were acquired at a stand-off distance of 570 m within the 7–14 \( \mu m \) spectral range at a resolution of 4 cm\( ^{-1} \). Path-integrated SO\( _2 \) concentrations were determined through cross-sectional scanning of the gas plume. To translate these optical measurements into an emission rate, the atmospheric dispersion of the plume was modeled using the Pasquill–Briggs approach, incorporating source parameters and meteorological data. Over two experimental series, the calculated average SO\( _2 \) emission rates were 15 kg/s and 22 kg/s, with coefficients of variation of 45.2\% and 32.8\%, respectively. This work highlights the value of FTIR spectroscopy as a powerful analytical tool for the remote, molecular-specific monitoring of atmospheric pollutants, providing a methodology applicable to the environmental chemistry of industrial emissions.