On the combustion chemistry of n- Heptane and n- Butanol blends

Darshan Karwat, Scott W. Wagnon, Margaret S. Wooldridge, Charles K. Westbrook

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

High-speed gas sampling experiments to measure the intermediate products formed during fuel decomposition remain challenging yet important experimental objectives. This article presents new speciation data on two important fuel reference compounds, n-heptane and n-butanol, at practical thermodynamic conditions of 700 K and 9 atm, for stoichiometric fuel-to-oxygen ratios and a dilution of 5.64 (molar ratio of inert gases to O2), and at two blend ratios, 80%-20% and 50%-50% by mole of n-heptane and n-butanol, respectively. When compared against 100% n-heptane ignition results, the experimental data show that n-butanol slows the reactivity of n-heptane. In addition, speciation results of n-butanol concentrations show that n-heptane causes n-butanol to react at temperatures where n-butanol in isolation would not be considered reactive. The chemical kinetic mechanism developed for this work accurately predicts the trends observed for species such as carbon monoxide, methane, propane, 1-butene, and others. However, the mechanism predicts a higher amount of n-heptane consumed at the first stage of ignition compared to the experimental data. Consequently, many of the species concentration predictions show a sharp rise at the first stage of ignition, a trend that is not observed experimentally. An important discovery is that the presence of n-butanol reduces the measured concentrations of the large linear alkenes, including heptenes, hexenes, and pentenes, showing that the addition of n-butanol affects the fundamental chemical pathways of n-heptane during ignition.

Original languageEnglish (US)
Pages (from-to)12406-12421
Number of pages16
JournalJournal of Physical Chemistry A
Volume116
Issue number51
DOIs
StatePublished - Dec 27 2012
Externally publishedYes

Fingerprint

combustion chemistry
1-Butanol
heptanes
ignition
Ignition
Alkenes
trends
hexenes
Noble Gases
Propane
butenes
n-heptane
Methane
propane
carbon monoxide
Carbon Monoxide
alkenes
dilution
rare gases
Reaction kinetics

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

On the combustion chemistry of n- Heptane and n- Butanol blends. / Karwat, Darshan; Wagnon, Scott W.; Wooldridge, Margaret S.; Westbrook, Charles K.

In: Journal of Physical Chemistry A, Vol. 116, No. 51, 27.12.2012, p. 12406-12421.

Research output: Contribution to journalArticle

Karwat, D, Wagnon, SW, Wooldridge, MS & Westbrook, CK 2012, 'On the combustion chemistry of n- Heptane and n- Butanol blends', Journal of Physical Chemistry A, vol. 116, no. 51, pp. 12406-12421. https://doi.org/10.1021/jp309358h
Karwat, Darshan ; Wagnon, Scott W. ; Wooldridge, Margaret S. ; Westbrook, Charles K. / On the combustion chemistry of n- Heptane and n- Butanol blends. In: Journal of Physical Chemistry A. 2012 ; Vol. 116, No. 51. pp. 12406-12421.
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