Combined impact of branching and unsaturation on the autoignition of binary blends in a motored engine

Handle URI:
http://hdl.handle.net/10754/563864
Title:
Combined impact of branching and unsaturation on the autoignition of binary blends in a motored engine
Authors:
Kang, Dongil; Kirby, Stephen R.; Agudelo, John Ramiro; Lapuerta, Magín; Al-Qurashi, Khalid; Boehman, André Louis
Abstract:
The impact of a branched and unsaturated compound (diisobutylene) mixed with simple hydrocarbons such as n-heptane and isooctane in binary blends on the autoignition behavior were investigated in a modified cooperative fuel research (CFR) engine at an equivlanece ratio of 0.5 and intake temperature of 120 °C. From this test condition, a homogeneous charge of fuel and intake air can be achieved. The test fuels were prepared by addition of 5-20 vol % diisobutylene into n-heptane and isooctane. The engine compression ratio (CR) was gradually increased from the lowest point to the point where significant high temperature heat release (HTHR) was observed, and this point is also referred to as the critical compression ratio (CCR). Heat release analysis showed that each n-heptane blend had a noticeable low temperature heat release (LTHR), which was not observed in the isooctane blends. The gradual addition of diisobutylene into each primary reference fuel contributed to retarded high temperature heat release in these binary blends, increasing the in-cylinder temperature and decreasing formation of CO. The 15 and 20 vol % blends of diisobutylene in isooctane were not able to reach high temperature heat release in the CFR engine system under these test conditions. The fundamental ignition behavior such as CCR and calculated % LTHR show the impact of the presence of the C-C double bond on ignition reactivity. Species concentration profiles obtained in condensed products from the engine exhaust were measured via gas chromatrography-mass spectrometry and -flame ionization detector. The major intermediate species for each blend were captured at a compression ratio selected just before the high temperature heat release was observed. Most intermediate species were derived from n-heptane and isooctane, while diisobutylene rarely participated in forming any major species, with the exception of the formation of 4,4-dimethyl-2-pentanone. Addition of diisobutylene exhibited opposite trends with regard to the abundance of intermediate species when blended with n-heptane versus with isooctane, due to the different degree of oxidation reactivity of n-heptane in comparison to isooctane.
KAUST Department:
Clean Combustion Research Center
Publisher:
American Chemical Society (ACS)
Journal:
Energy & Fuels
Issue Date:
20-Nov-2014
DOI:
10.1021/ef501629p
Type:
Article
ISSN:
08870624
Sponsors:
We gratefully acknowledge financial support from the KAUST Global Collaborative Research (GCR) program, the Spanish Ministry of Education, for the financial support for M.L.'s stay at the EMS Energy Institute at The Pennsylvania State University (Grant PR2010-0419), and the University of Antioquia for the financial support for J.A.'s stay at the EMS Energy Institute at The Pennsylvania State University.
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorKang, Dongilen
dc.contributor.authorKirby, Stephen R.en
dc.contributor.authorAgudelo, John Ramiroen
dc.contributor.authorLapuerta, Magínen
dc.contributor.authorAl-Qurashi, Khaliden
dc.contributor.authorBoehman, André Louisen
dc.date.accessioned2015-08-03T12:17:28Zen
dc.date.available2015-08-03T12:17:28Zen
dc.date.issued2014-11-20en
dc.identifier.issn08870624en
dc.identifier.doi10.1021/ef501629pen
dc.identifier.urihttp://hdl.handle.net/10754/563864en
dc.description.abstractThe impact of a branched and unsaturated compound (diisobutylene) mixed with simple hydrocarbons such as n-heptane and isooctane in binary blends on the autoignition behavior were investigated in a modified cooperative fuel research (CFR) engine at an equivlanece ratio of 0.5 and intake temperature of 120 °C. From this test condition, a homogeneous charge of fuel and intake air can be achieved. The test fuels were prepared by addition of 5-20 vol % diisobutylene into n-heptane and isooctane. The engine compression ratio (CR) was gradually increased from the lowest point to the point where significant high temperature heat release (HTHR) was observed, and this point is also referred to as the critical compression ratio (CCR). Heat release analysis showed that each n-heptane blend had a noticeable low temperature heat release (LTHR), which was not observed in the isooctane blends. The gradual addition of diisobutylene into each primary reference fuel contributed to retarded high temperature heat release in these binary blends, increasing the in-cylinder temperature and decreasing formation of CO. The 15 and 20 vol % blends of diisobutylene in isooctane were not able to reach high temperature heat release in the CFR engine system under these test conditions. The fundamental ignition behavior such as CCR and calculated % LTHR show the impact of the presence of the C-C double bond on ignition reactivity. Species concentration profiles obtained in condensed products from the engine exhaust were measured via gas chromatrography-mass spectrometry and -flame ionization detector. The major intermediate species for each blend were captured at a compression ratio selected just before the high temperature heat release was observed. Most intermediate species were derived from n-heptane and isooctane, while diisobutylene rarely participated in forming any major species, with the exception of the formation of 4,4-dimethyl-2-pentanone. Addition of diisobutylene exhibited opposite trends with regard to the abundance of intermediate species when blended with n-heptane versus with isooctane, due to the different degree of oxidation reactivity of n-heptane in comparison to isooctane.en
dc.description.sponsorshipWe gratefully acknowledge financial support from the KAUST Global Collaborative Research (GCR) program, the Spanish Ministry of Education, for the financial support for M.L.'s stay at the EMS Energy Institute at The Pennsylvania State University (Grant PR2010-0419), and the University of Antioquia for the financial support for J.A.'s stay at the EMS Energy Institute at The Pennsylvania State University.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleCombined impact of branching and unsaturation on the autoignition of binary blends in a motored engineen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalEnergy & Fuelsen
dc.contributor.institutionEMS Energy Institute, Department of Energy and Mineral Engineering, Pennsylvania State UniversityUniversity Park, PA, United Statesen
dc.contributor.institutionUniversidad de AntioquiaMedellin, Colombiaen
dc.contributor.institutionUniversidad de Castilla-La ManchaCuidad Real, Spainen
kaust.authorAl-Qurashi, Khaliden
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.