3.2 - IR Imaging of CO2: Basics, Experiments, and Potential Industrial Applications
- SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
- Proceedings IRS² 2011
- I3 - Gas Analysis
- M. Vollmer, K. Möllmann - Brandenburg University of Applied Sciences (Germany)
- 59 - 64
The detection of gases by thermal imaging due to absorption, scattering, or emission of IR radiation is a rather new application in the field of infrared thermal imaging. Strong absorption/ emission features allow detection of some gases already with broad band IR cameras in the MW and LW range. The industrial importance of several gases led to the development of sensitive cameras using narrowband cold filters in front of the detector. Such cameras are commercially available for detection of volatile organic compounds, SF6 and CO. Quantitative analysis of gas concentrations or gas flows is complicated although in principle also possible. In this work, we focus on CO2 which is probably the most important gas of the 21st century. The absorption bands for room temperature CO2 gas lie around a wavelength of 4.3μm, i.e. well within the spectral range of MW IR cameras.
The presentation will first outline the basics of gas detection using infrared cameras. Subsequently a large number of different thermal imaging experiments with CO2 is presented. These include comparison of broadband detection vs. narrowband detection in the MW range, visualization of pressure broadening effects, detection of low concentrations of the order of 500 ppm over short distances, detection of CO2 in exhaled air and in combustion processes, as well as visualization of absorption versus scattering and emission of radiation by gases. Most importantly, detection of well defined gas flows simulating gas leaks are presented and it is demonstrated that CO2 gas flows as small as 1ml/min, corresponding to CO2 masses of about 1kg/year may be detected. These experiments clearly demonstrate that IR gas imaging is well suited for a large number of potential industrial applications, e.g., in (CCS) technologies).