Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4764446 | Combustion and Flame | 2017 | 11 Pages |
Abstract
The unimolecular decomposition kinetics of methyl propanoate (MP), including the direct CâO/CâC bond fissions and molecular reaction channels, were studied by using high-level ab initio calculations and Rice-Ramsperger-Kassel-Marcus/master equation (RRKM/ME) theory. Four homolytic bond-fission and ten hydrogen transfer reactions of the MP unimolecular decomposition were identified. The phenomenological rate constants were determined using the RRKM/ME theory over a temperature range of 1000â2000Â K and a pressure range of 0.01Â atm to the high-pressure limit. At 1Â atm, the branching ratios show that the dissociation reactions MP â
- CH2C(O)OCH3Â +Â CH3, MP â CH3OC
- (O)Â +Â C2H5 and MP â CH3CH2C(O)O
- Â +Â CH3 dominate MP pyrolysis over the temperature range of 1000â1500Â K. Our calculated rate constants were adopted in a detailed kinetic model to reproduce the laser-absorption measured CO and CO2 concentration time-histories during the pyrolysis of 0.2% MP/Ar in a shock tube from 1292â1551Â K and at 1.6Â atm. The updated mechanism accurately predicted the early-time CO and CO2 formation over the entire temperature range. In particular, our mechanism well reproduced the CO2 time-histories from the early-time formation to the final plateau level.
- CH2C(O)OCH3Â +Â CH3, MP â CH3OC
- (O)Â +Â C2H5 and MP â CH3CH2C(O)O
- Â +Â CH3 dominate MP pyrolysis over the temperature range of 1000â1500Â K. Our calculated rate constants were adopted in a detailed kinetic model to reproduce the laser-absorption measured CO and CO2 concentration time-histories during the pyrolysis of 0.2% MP/Ar in a shock tube from 1292â1551Â K and at 1.6Â atm. The updated mechanism accurately predicted the early-time CO and CO2 formation over the entire temperature range. In particular, our mechanism well reproduced the CO2 time-histories from the early-time formation to the final plateau level.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Ning Hongbo, Wu Junjun, Ma Liuhao, Ren Wei, David F. Davidson, Ronald K. Hanson,