Small esters represent an important class of high octane biofuels for advanced spark ignition engines. They qualify for stringent fuel screening standards and could be synthesized through various pathways. In this work, we performed a detailed investigation of the combustion of two small esters, MA (methyl acetate) and EA (ethyl acetate), including quantum chemistry calculations, experimental studies of combustion characteristics and kinetic model development. The quantum chemistry calculations were performed to obtain rates for H-atom abstraction reactions involved in the oxidation chemistry of these fuels. The series of experiments include: a shock tube study to measure ignition delays at 15 and 30 bar, 1000–1450 K and equivalence ratios of 0.5, 1.0 and 2.0; laminar burning velocity measurements in a heat flux burner over a range of equivalence ratios [0.7–1.4] at atmospheric pressure and temperatures of 298 and 338 K; and speciation measurements during oxidation in a jet-stirred reactor at 800–1100 K for MA and 650–1000 K for EA at equivalence ratios of 0.5, 1.0 and at atmospheric pressure. The developed chemical kinetic mechanism for MA and EA incorporates reaction rates and pathways from recent studies along with rates calculated in this work. The new mechanism shows generally good agreement in predicting experimental data across the broad range of experimental conditions. The experimental data, along with the developed kinetic model, provides a solid groundwork towards improving the understanding the combustion chemistry of smaller esters.
|Original language||English (US)|
|Number of pages||10|
|Journal||Proceedings of the Combustion Institute|
|State||Published - Jul 17 2018|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors at KAUST acknowledge funding support from the Office of Sponsored Research under the Future Fuels Program. The authors at NUI Galway recognize funding support from Science Foundation Ireland via their Principal Investigator Program through project number 15/IA/3177. Cavallotti acknowledges the financial support of the Chemical Sciences and Engineering Division of Argonne National Laboratories for his sabbatical. The work by authors at LLNL was performed under the auspices of the U.S. Department of Energy (DOE), Contract DE-AC52-07NA27344 and was conducted as part of the Co-Optimization of Fuels & Engines (Co-Optima) project sponsored by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies and Vehicle Technologies Offices. The authors at Lund University acknowledge financial support from the Centre for Combustion Science and Technology (CECOST), and Swedish Research Council (VR) via project 2015-04042. Part of this material is based on work at Argonne supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, under Contract No. DE-AC02-06CH11357. The NREL research was conducted as part of the Co-Optimization of Fuels & Engines (Co-Optima) project sponsored by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies and Vehicle Technologies Offices.