We demonstrate the application of mode-locked mid-infrared dual frequency comb spectroscopy for combustion analysis. With two settings of the same dual-comb system, the measurement spans 1500 cm-1 from 2.8 to 5 μm with 0.0067 cm-1 (200 MHz) point spacing, or almost a quarter-million discrete comb modes. Using this broadband spectrometer, we quantify the pyrolysis and smoldering combustion of wood samples. Specifically, we measure 20-second time-resolved mole fractions of CH4, H2O, two isotopologues of CO2 (12C16O2, 13C16O2), two isotopologues of CO (12C16O, 13C16O), ethane, formaldehyde, methanol, formic acid, as well as gas temperature directly above radiatively heated wood samples. The combination of the fine spectral resolution and the broad bandwidth of the dual-comb spectrometer allows for precise separation of absorption signatures of individual molecules from the congested spectra.
KAUST Repository Item: Exported on 2022-06-30
Acknowledgements: We thank Dr. Aamir Farooq of King Abdullah University of Science and Technology and Dr. Timothy Johnson of Pacific Northwest National Laboratory for providing absorption cross-section reference sets. This work was supported by the Strategic Environmental Research and Development Program (W912HQ-16-C-0026), the National Science Foundation (CBET 1454496), the Defense Advanced Research Projects Agency (W31P4Q-15-1-0011), and NIST.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
- Chemical Engineering(all)
- Mechanical Engineering
- Physical and Theoretical Chemistry