Exploring the negative temperature coefficient behavior of acetaldehyde based on detailed intermediate measurements in a jet-stirred reactor

Acetaldehyde is an observed emission species and a key intermediate produced during the combustion and low-temperature oxidation of fossil and bio-derived fuels. Investigations into the low-temperature oxidation chemistry of acetaldehyde are essential to develop a better core mechanism and to better understand auto-ignition and cool flame phenomena. Here, the oxidation of acetaldehyde was studied at low-temperatures (528–946 K) in a jet-stirred reactor (JSR) with the corrected residence time of 2.7 s at 700 Torr. This work describes a detailed set of experimental results that capture the negative temperature coefficient (NTC) behavior in the low-temperature oxidation of acetaldehyde. The mole fractions of 28 species were measured as functions of the temperature by employing a vacuum ultra-violet photoionization molecular-beam mass spectrometer. To explain the observed NTC behavior, an updated mechanism was proposed, which well reproduces the concentration profiles of many observed peroxide intermediates. The kinetic analysis based on the updated mechanism reveals that the NTC behavior of acetaldehyde oxidation is caused by the competition between the O-addition to and the decomposition of the CHCO radical.

Citation

Tao T, Sun W, Hansen N, Jasper AW, Moshammer K, et al. (2018) Exploring the negative temperature coefficient behavior of acetaldehyde based on detailed intermediate measurements in a jet-stirred reactor. Combustion and Flame 192: 120–129. Available: http://dx.doi.org/10.1016/j.combustflame.2018.01.048.

Sponsors

We really appreciate the productive discussion with Dr. Ultan Burke and Dr. Henry J. Curran. This work is supported by the National Natural Science Foundation of China (Nos. 91741109 and 91541113). TT wants to thank for the support China Scholarship Council. The experiments profited from the expert technical assistance of Paul Fugazzi. This research used resources of the Advanced Light Source, supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DEAC02-05CH11231. NH, AWJ and KM were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-NA0003525. The work at Argonne is supported under Contract no. DE-AC02-06CH11357DOE-BES through the GPCP program.

Publisher

Elsevier BV

Journal

Combustion and Flame

ISSN

0010-2180