Research on Quantitative Analysis Method of Infrared Spectroscopy for Coal Mine Gases

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Monitoring

Background:

• Accurate coal mine gas detection is crucial for production safety.
• Fourier Transform Infrared (FTIR) spectroscopy offers sensitive, non-destructive online monitoring capabilities.
• Underground environments present challenges like spectral baseline drift and complex gas mixtures.

Purpose of the Study:

• To develop and validate a quantitative analysis method for coal mine gases using FTIR.
• To address challenges of spectral drift and overlapping absorption peaks in complex gas mixtures.
• To improve the precision and reliability of online gas analysis in coal mines.

Main Methods:

• Applied adaptive smoothness parameter penalized least squares for spectral baseline correction.
• Classified gases based on absorption peak characteristics (distinct vs. overlapping).
• Utilized spectral line selection with curve fitting for distinct peaks and a variable selection method with a backpropagation neural network for overlapping peaks.

Main Results:

• Achieved low detection limits for multiple gases (e.g., 0.1 ppm for SF6, 0.2 ppm for C2H2, 0.5 ppm for CH4).
• Quantification limits were below 10 ppm for all analyzed gases.
• Demonstrated high accuracy with absolute error < 0.3% F.S. and relative error < 10%.

Conclusions:

• The proposed FTIR quantitative analysis method effectively detects and quantifies coal mine gases.
• The method shows good predictive performance, enhancing safety in coal mine operations.
• This technique offers a reliable solution for online monitoring in challenging underground environments.