Effects of methyl substitution on the auto-ignition of C16 alkanes

Handle URI:
http://hdl.handle.net/10754/596051
Title:
Effects of methyl substitution on the auto-ignition of C16 alkanes
Authors:
Lapuerta, Magín; Hernández, Juan J.; Sarathy, Mani ( 0000-0002-3975-6206 )
Abstract:
The auto-ignition quality of diesel fuels, quantified by their cetane number or derived cetane number (DCN), is a critical design property to consider when producing and upgrading synthetic paraffinic fuels. It is well known that auto-ignition characteristics of paraffinic fuels depend on their degree of methyl substitution. However, there remains a need to study the governing chemical functionalities contributing to such ignition characteristics, especially in the case of methyl substitutions, which have not been studied in detail. In this work, the auto-ignition of 2,6,10-trimethyltridecane has been compared with the reference hydrocarbons used for cetane number determination, i.e. n-hexadecane and heptamethylnonane, all of them being C16 isomers. Results from a constant-volume combustion chamber under different pressure and temperature initial conditions showed that the ignition delay time for both cool flame and main combustion events increased less from n-hexadecane to trimethyltridecane than from trimethyltridecane to heptamethylnonane. Additional experimental results from blends of these hydrocarbons, together with kinetic modelling, showed that auto-ignition times and combustion rates were correlated to the concentration of the functional groups indicative of methyl substitution, although not in a linear manner. When the concentration of these functional groups decreased, the first stage OH radical concentration increased and ignition delay times decreased, whereas when their concentration increased, H2O2 production was slower and ignition was retarded. Contrary to the ignition delay times, DCN was correlated linearly with functional groups, thus homogenizing the range of values and clarifying the differences between fuels.
KAUST Department:
Clean Combustion Research Center
Citation:
Effects of methyl substitution on the auto-ignition of C16 alkanes 2016, 164:259 Combustion and Flame
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
18-Dec-2015
DOI:
10.1016/j.combustflame.2015.11.024
Type:
Article
ISSN:
00102180
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0010218015004228
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorLapuerta, Magínen
dc.contributor.authorHernández, Juan J.en
dc.contributor.authorSarathy, Manien
dc.date.accessioned2016-02-11T13:18:32Zen
dc.date.available2016-02-11T13:18:32Zen
dc.date.issued2015-12-18en
dc.identifier.citationEffects of methyl substitution on the auto-ignition of C16 alkanes 2016, 164:259 Combustion and Flameen
dc.identifier.issn00102180en
dc.identifier.doi10.1016/j.combustflame.2015.11.024en
dc.identifier.urihttp://hdl.handle.net/10754/596051en
dc.description.abstractThe auto-ignition quality of diesel fuels, quantified by their cetane number or derived cetane number (DCN), is a critical design property to consider when producing and upgrading synthetic paraffinic fuels. It is well known that auto-ignition characteristics of paraffinic fuels depend on their degree of methyl substitution. However, there remains a need to study the governing chemical functionalities contributing to such ignition characteristics, especially in the case of methyl substitutions, which have not been studied in detail. In this work, the auto-ignition of 2,6,10-trimethyltridecane has been compared with the reference hydrocarbons used for cetane number determination, i.e. n-hexadecane and heptamethylnonane, all of them being C16 isomers. Results from a constant-volume combustion chamber under different pressure and temperature initial conditions showed that the ignition delay time for both cool flame and main combustion events increased less from n-hexadecane to trimethyltridecane than from trimethyltridecane to heptamethylnonane. Additional experimental results from blends of these hydrocarbons, together with kinetic modelling, showed that auto-ignition times and combustion rates were correlated to the concentration of the functional groups indicative of methyl substitution, although not in a linear manner. When the concentration of these functional groups decreased, the first stage OH radical concentration increased and ignition delay times decreased, whereas when their concentration increased, H2O2 production was slower and ignition was retarded. Contrary to the ignition delay times, DCN was correlated linearly with functional groups, thus homogenizing the range of values and clarifying the differences between fuels.en
dc.language.isoenen
dc.publisherElsevier BVen
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0010218015004228en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Combustion and Flame. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Combustion and Flame, 18 December 2015. DOI: 10.1016/j.combustflame.2015.11.024en
dc.subjectAuto-ignitionen
dc.subjectCombustionen
dc.subjectBiofuelsen
dc.subjectDiesel engineen
dc.subjectBranched alkanesen
dc.titleEffects of methyl substitution on the auto-ignition of C16 alkanesen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalCombustion and Flameen
dc.eprint.versionPost-printen
dc.contributor.institutionEscuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla La-Mancha, Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spainen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorSarathy, Manien
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