Remote Identification and Quantification of Industrial Smokestack Effluents via Imaging Fourier-Transform Spectroscopy

• Published in: Environmental science & technology 2010-12, Vol.44 (24), p.9390-9397
• Main Authors: Gross, Kevin C, Bradley, Kenneth C, Perram, Glen P
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air Pollutants - chemistry; Applied sciences; Carbon Dioxide - analysis; Carbon Dioxide - chemistry; Carbon Monoxide - analysis; Carbon Monoxide - chemistry; Data Interpretation, Statistical; Effluents; Environmental Measurements Methods; Environmental Monitoring - instrumentation; Environmental Monitoring - methods; Environmental science; Exact sciences and technology; Fourier transforms; Hydrochloric Acid - analysis; Hydrochloric Acid - chemistry; Industrial Waste - analysis; Industrial wastes; Models, Chemical; Nitrogen Oxides - analysis; Nitrogen Oxides - chemistry; Pollution; Remote Sensing Technology; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; Steam - analysis; Sulfur Dioxide - analysis; Sulfur Dioxide - chemistry
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es101823z

Industrial smokestack plume emissions were remotely measured with a midwave infrared (1800−3000 cm−1) imaging Fourier-transform spectrometer operating at moderate spatial (128 × 64 with 19.4 × 19.4 cm2 per pixel) and high spectral (0.25 cm−1) resolution over a 20 min period. Strong emissions from CO2, H2O, SO2, NO, HCl, and CO were observed. A single-layer plume radiative transfer model was used to estimate temperature T and effluent column densities q i for each pixel’s spectrum immediately above the smokestack exit. Across the stack, temperature was uniform with T = 396.3 ± 1.3 K (mean ± stdev), and each q i varied in accordance with the plume path length defined by its cylindrical geometry. Estimated CO2 and SO2 volume fractions of 8.6 ± 0.4% and 380 ± 23 ppmv, respectively, compared favorably with in situ measurements of 9.40 ± 0.03% and 383 ± 2 ppmv. Total in situ NO x concentration (NO + NO2) was reported at 120 ± 1 ppmv. While NO2 was not spectrally detected, NO was remotely observed with a concentration of 104 ± 7 ppmv. Concentration estimates for the unmonitored species CO, HCl, and H2O were 14.4 ± 0.3 ppmv, 88 ± 1 ppmv, and 4.7 ± 0.1%, respectively.