TY - JOUR
T1 - A reaction mechanism for ozone dissociation and reaction with hydrogen at elevated temperature
AU - Jian, Jie
AU - Hashemi, Hamid
AU - Wu, Hao
AU - Jasper, Ahren W.
AU - Glarborg, Peter
PY - 2022
Y1 - 2022
N2 - Ozone is considered to be an
effective combustion promotor and has the potential to be applied to a
variety of fuels. In this work, the reaction mechanism for thermal conversion
of ozone in the absence and presence of hydrogen was updated, based on
theoretical work and novel flow reactor experiments. The H2-O3
reaction subset, which is the foundation for modeling ozone-assisted
combustion of any hydrogen-containing fuel, was further validated
against experiments from literature. Experiments for conversion of O2-O3 and H2-O2-O3, highly diluted in N2, were conducted in an atmospheric pressure flow reactor at temperatures of 400–575 K. In establishing the kinetic model, special attention was paid to the key ozone reactions: O3 (+M) = O2 + O (+M) (R1), O3 + O = 2O2 (R2), and O3 + OH = O2 + HO2 (R4). For ozone dissociation (R1), relative third-body collision efficiencies compared to N2 were calculated for Ar, O2, and O3, allowing a more accurate assessment of k1(N2), k1(O2) and k1(O3). The flow reactor data for H2-O2-O3
provided information on the competition between hydrogen and ozone for
radicals and served to constrain the rate constants for O3 + O (R2) and O3 + OH (R4). Comparison between experiments and model predictions show that all current H2-O3
mechanisms predict well ozone dissociation, but only the present
mechanism provides a good agreement for the hydrogen-ozone reaction
rate. A sensitivity analysis showed that the competition for oxygen
atoms and hydroxyl radicals between ozone and hydrogen molecules has a profound influence on both the flow reactor reaction rate and flame speed.
AB - Ozone is considered to be an
effective combustion promotor and has the potential to be applied to a
variety of fuels. In this work, the reaction mechanism for thermal conversion
of ozone in the absence and presence of hydrogen was updated, based on
theoretical work and novel flow reactor experiments. The H2-O3
reaction subset, which is the foundation for modeling ozone-assisted
combustion of any hydrogen-containing fuel, was further validated
against experiments from literature. Experiments for conversion of O2-O3 and H2-O2-O3, highly diluted in N2, were conducted in an atmospheric pressure flow reactor at temperatures of 400–575 K. In establishing the kinetic model, special attention was paid to the key ozone reactions: O3 (+M) = O2 + O (+M) (R1), O3 + O = 2O2 (R2), and O3 + OH = O2 + HO2 (R4). For ozone dissociation (R1), relative third-body collision efficiencies compared to N2 were calculated for Ar, O2, and O3, allowing a more accurate assessment of k1(N2), k1(O2) and k1(O3). The flow reactor data for H2-O2-O3
provided information on the competition between hydrogen and ozone for
radicals and served to constrain the rate constants for O3 + O (R2) and O3 + OH (R4). Comparison between experiments and model predictions show that all current H2-O3
mechanisms predict well ozone dissociation, but only the present
mechanism provides a good agreement for the hydrogen-ozone reaction
rate. A sensitivity analysis showed that the competition for oxygen
atoms and hydroxyl radicals between ozone and hydrogen molecules has a profound influence on both the flow reactor reaction rate and flame speed.
KW - hydrogen
KW - ozone
KW - Kinetic mechanism
KW - oxidation
KW - Flow reactor
KW - Flame
U2 - 10.1016/j.fuel.2022.124138
DO - 10.1016/j.fuel.2022.124138
M3 - Journal article
SN - 0016-2361
VL - 322
JO - Fuel
JF - Fuel
M1 - 124138
ER -