Quantitative measurements of broad-band mid-infrared absorption spectra of formaldehyde, acetaldehyde, and acetone at combustion-relevant temperatures near 5.7 µm. (June 2020)

• Record Type: Journal Article
• Authors: Ding, Y.; Peng, W.Y.; Strand, C.L.; Hanson, R.K.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 248(2020)
• Publication Date: 2020-06
• Subjects: Laser absorption spectroscopy -- Cross section -- Shock tube -- EC-QCL -- Water -- 1, 3, 5-trioxane; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2020.106981
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: Employed a broad-scan, rapid-tuning EC-QCL for the collection of high-temperature absorption spectra in a shock tube. Reported the formaldehyde absorption spectrum in its ν 2 vibrational band at 998 K, 3.8 atm. Measurements of formaldehyde cross sections showed reasonable agreement with HITRAN 2016. Under predictions in spectral simulations were due to missing hotband and high-J rovibrational transitions. Acquired the first-ever experimental high-temperature absorption spectra for acetaldehyde and acetone. Abstract: Temperature-dependent absorption cross sections of formaldehyde, acetaldehyde, and acetone are presented for their CO stretching bands near 5.7 µm. The measurement methodology employs a broad-scan, rapid-tuning EC-QCL in conjunction with shock tube facilities and can provide quantitative spectroscopic information with an average spectral resolution of 0.6 cm −1 at a tuning rate in excess of 30 cm −1 /ms. The absorption spectrum of formaldehyde in the ν 2 vibrational band is reported at 998 K and 3.8 atm, showing reasonable agreement with spectral simulations based on HITRAN 2016. The residuals are ascribed to the emergence of hotbands and high-J rovibrational transitions at elevated temperatures. The first high-temperature absorption cross section measurements of acetaldehyde and acetone are reported near atmospheric pressure at combustion-related temperatures up to 1000 K, with strong temperature broadening observed in the measured spectra. The results presented are archived in the Stanford ShockGas-IR database and are expected to be useful in future spectroscopic studies.