Title: A comprehensive experimental and kinetic modeling study of 1-hexene

Abstract

It is important to understand the low-temperature chemistry of 1-hexene as it is used as a representative alkene component in gasoline surrogate fuels. Ignition delay times (IDTs) of 1-hexene measured in rapid compression machines (RCMs) can be used to validate its low-temperature chemistry. However, volume history profiles are not available for published RCM IDT data. This has restricted the validation of the low-temperature chemistry of 1-hexene at engine-relevant conditions (i.e. at low temperatures and high pressures). Thus, new RCM IDT data with associated volume history profiles are needed. In this study, both an RCM and a high-pressure shock tube (ST) are employed to measure IDTs of 1-hexene at equivalence ratios of 0.5, 1.0 and 2.0 in ‘air’ and at pressures of 15 and 30 atm. A cool-flame (first stage) and total (second stage) ignition was observed in the RCM experiments. Moreover, carbon monoxide and water versus time histories produced during 1-hexene oxidation at highly diluted conditions were measured in a ST. A new detailed chemical kinetic model describing 1-hexene oxidation is proposed and validated using these new measured data together with various experimental data available in the literature. The kinetic model can predict well the auto-ignition behavior and oxidation processesmore » of 1-hexene at various conditions. The rate constants and branching ratio for hydroxyl radical addition to the double bond of 1-hexene are particularly important and discussed based on the experimental and theoretically calculated results from previous studies as well as validation results from jet-stirred reactor (JSR) species profiles. Flux and sensitivity analyses are performed to determine the important reaction classes for 1-hexene oxidation and show that the reactions associated with hydroxy radical addition to the double bond contribute most to the low-temperature reactivity of 1-hexene. In the negative temperature coefficient (NTC) regime, the isomerization of hexenyl-peroxy radicals promotes fuel reactivity due to its associated chain branching pathways.« less

Authors:

Dong, Shijun; Aul, Christopher; Gregoire, Claire ;

• Search DOE PAGES for author "Gregoire, Claire"
• Search DOE PAGES for ORCID "0000-0002-0085-0553"

Cooper, Sean P.; Mathieu, Olivier; Petersen, Eric L.; Rodriguez, Jose; Mauss, Fabian ;

• Search DOE PAGES for author "Mauss, Fabian"
• Search DOE PAGES for ORCID "0000-0002-6305-8213"

Wagnon, Scott W. ;

• Search DOE PAGES for author "Wagnon, Scott W."
• Search DOE PAGES for ORCID "0000-0003-2172-5230"

Kukkadapu, Goutham; Pitz, William J.; Curran, Henry J.

Publication Date:

Fri Oct 01 00:00:00 EDT 2021

Research Org.:

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Bioenergy Technologies Office; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office

OSTI Identifier:

1788124

Alternate Identifier(s):

OSTI ID: 1807759

Report Number(s):

LLNL-JRNL-818698
Journal ID: ISSN 0010-2180; S0010218021002595; 111516; PII: S0010218021002595

Grant/Contract Number:  

AC52-07NA27344

Resource Type:

Published Article

Journal Name:

Combustion and Flame

Additional Journal Information:

Journal Name: Combustion and Flame Journal Volume: 232 Journal Issue: C; Journal ID: ISSN 0010-2180

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Energy conservation; inorganic chemistry; organic chemistry; physical chemistry; analytical chemistry; 1-hexene; oxidation; rapid cmpression machine; high-pressure shock tube; ignition delay time