Separation Method for Cross-Aliased Near-IR Absorption Lines of C2H4: A Coal Spontaneous Combustion Marker

• Published in: Journal of applied spectroscopy Vol. 90; no. 1; pp. 189 - 197
• Main Authors: Wang, Weifeng, Liu, Hanfei, Wie, Gaoming, Yang, Bo, Ren, Lifeng, Li, Jun, Liu, Bao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2023; Springer Nature B.V
• Subjects: Absorptivity; Aliasing; Analytical Chemistry; Atomic/Molecular Structure and Spectra; Errors; Helium; Interference; Methane; Near infrared radiation; Physics; Physics and Astronomy; Separation; Space telescopes; Spontaneous combustion; H; C; coal spontaneous combustion; aliasing interference; representative gas; absorption line
• ISSN: 0021-9037; 1573-8647
• DOI: 10.1007/s10812-023-01521-x

To tackle the cross-interference problem between CH 4 and C 2 H 4 and the aliasing interference problem of C 2 H 4 itself, on the basis of the sparse decomposition theory, multiple Lorentz function-based methods were proposed for separating the cross-aliasing interference of near-infrared (IR) C 2 H 4 absorption lines. A quadruple Lorentz function-based separation model describing the absorption coefficient of C 2 H 4 is developed, with which the absorption lines of background gas and to-be-measured C 2 H 4 were separated from the absorption lines of mixed gas, thereby effectively separating the absorption line of C 2 H 4 and accurately measuring its concentration. The results show that the maximum errors of C 2 H 4 and CH 4 gasometrical analyses are 5.3 × 10 −6 /201.7 × 10 −6 and 57 × 10 −6 /5000 × 10 −6 , respectively. The proposed method effectively eliminates the errors caused by cross-aliasing interference of C 2 H 4 absorption lines in the near-IR bands and improves the detection accuracy of the TDLAS gas detection system. The findings of this study provide a feasible solution to the cross-aliasing interference problem of IR absorption lines.