The Role of Intermediate-Temperature Heat Release in Octane Sensitivity of Fuels with Matching Research Octane Number
Type
ArticleAuthors
Singh, Eshan
Sarathy, Mani

KAUST Department
Biological and Environmental Science and Engineering (BESE) DivisionChemical Engineering Program
Clean Combustion Research Center
Combustion and Pyrolysis Chemistry (CPC) Group
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2021-02-16Online Publication Date
2021-02-16Print Publication Date
2021-03-04Embargo End Date
2022-02-16Submitted Date
2020-11-17Permanent link to this record
http://hdl.handle.net/10754/667491
Metadata
Show full item recordAbstract
Improving the efficiency of internal combustion engines is important for reducing global greenhouse gas emissions; the efficiency of spark ignition (SI) engines is limited by the knock phenomenon. As opposed to naturally aspirated engines, turbocharged engines operate at beyond research octane number (RON) conditions, and fuel octane sensitivity (OS = RON – motor octane number (MON)) becomes important under such conditions. Previous work by this group [ Energy Fuels 2017, 31, 1945−1960, DOI: 10.1021/acs.energyfuels.6b02659] elucidated the chemical kinetic origins of OS; this study is extended to provide a qualitative, as well as quantitative, definition of OS, based on fundamental ignition markers. A varying amount of toluene is blended with various primary reference fuels to match the ignition delay of the targeted research octane number fuels, allowing a range of octane sensitivities for each research octane number. This study establishes a correlation between OS and heat release rates at low, intermediate, and high temperatures. The significance and chemical origins of intermediate-temperature heat release in defining the OS of toluene blended in a mixture of iso-octane and n-heptane is also clarified. For the toluene–iso-octane–n-heptane mixtures considered here, low-temperature reactivity was not found to be a key marker of OS. The results also show areas of improved efficiency in beyond RON operating conditions, where high-sensitivity fuels could be beneficial.Citation
Singh, E., & Sarathy, S. M. (2021). The Role of Intermediate-Temperature Heat Release in Octane Sensitivity of Fuels with Matching Research Octane Number. Energy & Fuels. doi:10.1021/acs.energyfuels.0c03883Sponsors
This work was supported by King Abdullah University of Science and Technology (KAUST) with funds allocated to the Clean Combustion Research Center. We gratefully acknowledge contributions from the KAUST Clean Fuels Consortium (KCFC) and its member companies.Publisher
American Chemical Society (ACS)Journal
Energy & FuelsAdditional Links
https://pubs.acs.org/doi/10.1021/acs.energyfuels.0c03883ae974a485f413a2113503eed53cd6c53
10.1021/acs.energyfuels.0c03883