TY - JOUR
T1 - Quantitative measurements of HO2/H2O2 and intermediate species in low and intermediate temperature oxidation of dimethyl ether
AU - Kurimoto, Naoki
AU - Brumfield, Brian
AU - Yang, Xueliang
AU - Wada, Tomoya
AU - Diévart, Pascal
AU - Wysocki, Gerard
AU - Ju, Yiguang
N1 - Funding Information:
Partial support for this research was through the Andlinger Innovation Fund of Princeton University . YJ would like to acknowledge funding support from the NETL University Turbine Program and the US Department of Energy, Office of Basic Energy Sciences as part of an Energy Frontier Research Center on Combustion with Grant No. DE-SC0001198 (Kinetic study). NK acknowledges financial support on biofuels from DENSO CORPORATION , and also thanks Prof. F.L. Dryer at Princeton University for the discussion of 2D modeling.
Publisher Copyright:
© 2014 The Combustion Institute.
PY - 2015
Y1 - 2015
N2 - As two of the most important species that characterize hydrocarbon low temperature ignition, HO2 and H2O2 formation during dimethyl ether (DME) oxidation was quantified using the same experimental conditions, for the first time, in an atmospheric flow reactor at low and intermediate temperature range. Dual-Modulation Faraday Rotation Spectroscopy (DM-FRS) and Molecular Beam Mass Spectrometry (MBMS) were used to measure HO2 and H2O2 respectively. DME and other important intermediate species such as CH2O and CO are also measured by MBMS between 400 and 1150 K at different fuel concentrations. Species profiles in the reactor were calculated by using both zero- and two-dimensional computations with different detailed kinetics for cross-validation and comparison with experimental results. The models predict adequately the low and intermediate oxidation temperature windows near 600 and 1000 K, respectively. However, both models over-predicted the DME consumption as well as CO, HO2 and H2O2 formations at the low temperature oxidation window by more than a factor of four. Moreover, although the model predicted reasonably well the formation of CH2O and CO/CO2 at the intermediate temperature oxidation window, the concentration of H2O2 was also over-predicted, suggesting the large uncertainties existing in the DME low temperature chemistry and in H2O2 chemistry at intermediate temperature. Furthermore, to analyze the uncertainty of the low temperature chemistry, a branching ratio of QOOH decomposition to CH2O was derived using measured DME, CH2O and CO concentrations. The large difference between the modeled and measured branching ratios of QOOH decomposition suggests an underestimated QOOH decomposition rate to form CH2O in the current DME models.
AB - As two of the most important species that characterize hydrocarbon low temperature ignition, HO2 and H2O2 formation during dimethyl ether (DME) oxidation was quantified using the same experimental conditions, for the first time, in an atmospheric flow reactor at low and intermediate temperature range. Dual-Modulation Faraday Rotation Spectroscopy (DM-FRS) and Molecular Beam Mass Spectrometry (MBMS) were used to measure HO2 and H2O2 respectively. DME and other important intermediate species such as CH2O and CO are also measured by MBMS between 400 and 1150 K at different fuel concentrations. Species profiles in the reactor were calculated by using both zero- and two-dimensional computations with different detailed kinetics for cross-validation and comparison with experimental results. The models predict adequately the low and intermediate oxidation temperature windows near 600 and 1000 K, respectively. However, both models over-predicted the DME consumption as well as CO, HO2 and H2O2 formations at the low temperature oxidation window by more than a factor of four. Moreover, although the model predicted reasonably well the formation of CH2O and CO/CO2 at the intermediate temperature oxidation window, the concentration of H2O2 was also over-predicted, suggesting the large uncertainties existing in the DME low temperature chemistry and in H2O2 chemistry at intermediate temperature. Furthermore, to analyze the uncertainty of the low temperature chemistry, a branching ratio of QOOH decomposition to CH2O was derived using measured DME, CH2O and CO concentrations. The large difference between the modeled and measured branching ratios of QOOH decomposition suggests an underestimated QOOH decomposition rate to form CH2O in the current DME models.
KW - Dimethyl ether
KW - Faraday rotation spectroscopy
KW - HO and HO diagnostics
KW - Low temperature oxidation in flow reactor
KW - Molecular beam mass spectrometry
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U2 - 10.1016/j.proci.2014.05.120
DO - 10.1016/j.proci.2014.05.120
M3 - Article
AN - SCOPUS:84947543771
SN - 1540-7489
VL - 35
SP - 457
EP - 464
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 1
ER -