• DOI:10.1088/1361-6501/ac22ef
• Corpus ID: 238246785

Thermometry and speciation for high-temperature and -pressure methane pyrolysis using shock tubes and dual-comb spectroscopy

@article{Pinkowski2021ThermometryAS,
  title={Thermometry and speciation for high-temperature and -pressure methane pyrolysis using shock tubes and dual-comb spectroscopy},
  author={Nicolas H Pinkowski and Pujan Biswas and Jiankun Shao and Christopher L. Strand and Ronald K. Hanson},
  journal={Measurement Science and Technology},
  year={2021},
  volume={32}
}

• N. Pinkowski, Pujan Biswas, +2 authors R. Hanson
• Published 2021
• Physics, Chemistry
• Measurement Science and Technology

Quantum-cascade-laser dual-comb spectroscopy (QCL-DCS) is a promising technology with ultra-fast time resolution capabilities for chemical kinetics, atmospheric gas sensing, and combustion applications. A pair of quantum-cascade frequency combs were used to measure absorbance from methane’s ν4 band between 1270 and 1315 cm−1 at high-temperature and -pressure conditions that were generated using a high-pressure shock tube. Results here mark a major improvement over previous QCL-DCS measurements in shock tubes. Improvements came from a unique spectral-filtering strategy to correct for a bimodal power-spectral density of QCL frequency combs and careful optimization of the laser setup and experimental conditions. Our modified QCL-DCS was ultimately used to measure temperature within 2% and methane mole fraction within 5% by fitting HITEMP spectral simulations to spectra recorded at 4 μs temporal resolution. We measure temperature and species time-histories during methane pyrolysis at conditions between 1212–1980 K, and 12–17 atm, all at 4 μs resolution. Good agreement is observed with kinetic models, illustrating the potential of future applications of DCS in kinetics and combustion research.