High-pressure pyrolysis and oxidation of ethanol

Hamid Hashemi*, Jakob M. Christensen, Peter Glarborg

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The pyrolysis and oxidation of ethanol has been investigated at temperatures of 600–900 K, a pressure of 50 bar and residence times of 4.3–6.8 s in a laminar flow reactor. The experiments, conducted with mixtures highly diluted in nitrogen, covered fuel-air equivalence ratios (Φ) of 0.1, 1.0, 43, and ∞ . Ethanol pyrolysis was observed at temperatures above 850 K. The onset temperature of ethanol oxidation occurred at 700–725 K over a wide range of stoichiometries. A considerable yield of aldehydes was detected at intermediate temperatures. A detailed chemical kinetic model was developed and evaluated against the present data as well as ignition delay times and flame speed measurements from literature. The model predicted the onset of fuel conversion and the composition of products from the flow reactor experiments fairly well. It also predicted well ignition delays above 900 K whereas it overpredicted reported flame speeds slightly. The results of sensitivity analyses revealed the importance of the reaction between ethanol and the hydroperoxyl radical for ignition at high pressure and intermediate temperatures. An accurate determination of the rate coefficients for this reaction is important to improve the reliability of modeling predictions.
Original languageEnglish
JournalFuel
Volume218
Pages (from-to)247-257
ISSN0016-2361
DOIs
Publication statusPublished - 2018

Keywords

  • Ethanol
  • Ignition
  • High pressure
  • Reaction mechanism

Cite this

@article{cbef05625ef64b8d9d6f0e80482bd591,
title = "High-pressure pyrolysis and oxidation of ethanol",
abstract = "The pyrolysis and oxidation of ethanol has been investigated at temperatures of 600–900 K, a pressure of 50 bar and residence times of 4.3–6.8 s in a laminar flow reactor. The experiments, conducted with mixtures highly diluted in nitrogen, covered fuel-air equivalence ratios (Φ) of 0.1, 1.0, 43, and ∞ . Ethanol pyrolysis was observed at temperatures above 850 K. The onset temperature of ethanol oxidation occurred at 700–725 K over a wide range of stoichiometries. A considerable yield of aldehydes was detected at intermediate temperatures. A detailed chemical kinetic model was developed and evaluated against the present data as well as ignition delay times and flame speed measurements from literature. The model predicted the onset of fuel conversion and the composition of products from the flow reactor experiments fairly well. It also predicted well ignition delays above 900 K whereas it overpredicted reported flame speeds slightly. The results of sensitivity analyses revealed the importance of the reaction between ethanol and the hydroperoxyl radical for ignition at high pressure and intermediate temperatures. An accurate determination of the rate coefficients for this reaction is important to improve the reliability of modeling predictions.",
keywords = "Ethanol, Ignition, High pressure, Reaction mechanism",
author = "Hamid Hashemi and Christensen, {Jakob M.} and Peter Glarborg",
year = "2018",
doi = "10.1016/j.fuel.2017.12.085",
language = "English",
volume = "218",
pages = "247--257",
journal = "Fuel",
issn = "0016-2361",
publisher = "Elsevier",

}

High-pressure pyrolysis and oxidation of ethanol. / Hashemi, Hamid; Christensen, Jakob M.; Glarborg, Peter.

In: Fuel, Vol. 218, 2018, p. 247-257.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - High-pressure pyrolysis and oxidation of ethanol

AU - Hashemi, Hamid

AU - Christensen, Jakob M.

AU - Glarborg, Peter

PY - 2018

Y1 - 2018

N2 - The pyrolysis and oxidation of ethanol has been investigated at temperatures of 600–900 K, a pressure of 50 bar and residence times of 4.3–6.8 s in a laminar flow reactor. The experiments, conducted with mixtures highly diluted in nitrogen, covered fuel-air equivalence ratios (Φ) of 0.1, 1.0, 43, and ∞ . Ethanol pyrolysis was observed at temperatures above 850 K. The onset temperature of ethanol oxidation occurred at 700–725 K over a wide range of stoichiometries. A considerable yield of aldehydes was detected at intermediate temperatures. A detailed chemical kinetic model was developed and evaluated against the present data as well as ignition delay times and flame speed measurements from literature. The model predicted the onset of fuel conversion and the composition of products from the flow reactor experiments fairly well. It also predicted well ignition delays above 900 K whereas it overpredicted reported flame speeds slightly. The results of sensitivity analyses revealed the importance of the reaction between ethanol and the hydroperoxyl radical for ignition at high pressure and intermediate temperatures. An accurate determination of the rate coefficients for this reaction is important to improve the reliability of modeling predictions.

AB - The pyrolysis and oxidation of ethanol has been investigated at temperatures of 600–900 K, a pressure of 50 bar and residence times of 4.3–6.8 s in a laminar flow reactor. The experiments, conducted with mixtures highly diluted in nitrogen, covered fuel-air equivalence ratios (Φ) of 0.1, 1.0, 43, and ∞ . Ethanol pyrolysis was observed at temperatures above 850 K. The onset temperature of ethanol oxidation occurred at 700–725 K over a wide range of stoichiometries. A considerable yield of aldehydes was detected at intermediate temperatures. A detailed chemical kinetic model was developed and evaluated against the present data as well as ignition delay times and flame speed measurements from literature. The model predicted the onset of fuel conversion and the composition of products from the flow reactor experiments fairly well. It also predicted well ignition delays above 900 K whereas it overpredicted reported flame speeds slightly. The results of sensitivity analyses revealed the importance of the reaction between ethanol and the hydroperoxyl radical for ignition at high pressure and intermediate temperatures. An accurate determination of the rate coefficients for this reaction is important to improve the reliability of modeling predictions.

KW - Ethanol

KW - Ignition

KW - High pressure

KW - Reaction mechanism

U2 - 10.1016/j.fuel.2017.12.085

DO - 10.1016/j.fuel.2017.12.085

M3 - Journal article

VL - 218

SP - 247

EP - 257

JO - Fuel

JF - Fuel

SN - 0016-2361

ER -