Title: Influence of ozone addition on the low-temperature oxidation of dimethyl ether in a jet-stirred reactor

Abstract

The influence of ozone addition on the low-temperature oxidation of dimethyl ether (DME) was investigated experimentally in an atmospheric-pressure jet-stirred reactor, over the temperature range of 400–800 K. Detailed speciation information was obtained by employing synchrotron vacuum ultraviolet photoionization mass spectrometry. Experimental results revealed that the ozone addition had a positive influence on the production of the highly reactive intermediates. Moreover, the low-temperature reactivity of DME was significantly enhanced, which resulted in the broadening of the temperature window of fuel consumption and intermediates formation at lower temperatures. Therefore, novel experimental data of the low temperature regime (400–500 K) could be obtained. The data set of this special temperature regime yielded insights into the DME low-temperature kinetics, which were further supported with modeling analysis based on two existing DME models (Metcalfe et al., 2013; Wang et al., 2015) combined with an ozone sub-mechanism (Zhao et al., 2016). The analysis showed that temperature-sensitive reactions such as the second oxygen channel could be nearly “frozen” at this low temperature (T < 440 K). Furthermore, the production of some intermediates was found to be strongly governed by reaction pairs, such as CH₃OCH₂ + O₂ = CH₃OCH₂O₂ and CH₃OCH₂ + O₂ = ₂CH₂O + OHmore » for the CH₂O formation. This finding could be useful for examining branching ratios in both models, and the analysis suggested the further modification of the branching ratios for the oxygen addition to CH₃OCH₂O₂ pathways and the CH₃OCH₂O₂ self-reactions were required. Finally, the influences of the O₃ addition in the sensitive reactions of the fuel initial low-temperature oxidation were investigated in this work. It was interesting to note that O₃ addition could change the dominating reactions in the initial low-temperature oxidation, by the addition of some O₃-related pathways with relatively high sensitivity.« less

Authors:

Liao, Handong ^[1]; Kang, Shiqing ^[1]; Hansen, Nils ^[2]; Zhang, Feng ^[3]; Yang, Bin ^[1]

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+ Show Author Affiliations

1. Tsinghua Univ., Beijing (China)
2. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
3. Univ. of Science and Technology of China, Hefei (China)

Publication Date:

Mon Jan 20 00:00:00 EST 2020

Research Org.:

Sandia National Lab. (SNL-CA), Livermore, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1639059

Alternate Identifier(s):

OSTI ID: 1691872

Report Number(s):

SAND2020-6337J
Journal ID: ISSN 0010-2180; 686808

Grant/Contract Number:  

AC04-94AL85000; DEAC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Combustion and Flame

Additional Journal Information:

Journal Volume: 214; Journal ID: ISSN 0010-2180

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY