The octane numbers of ethanol blended with gasoline and its surrogates

Foong, Tien Mun; Morganti, Kai; Brear, Michael J.; Silva, Gabriel da; Yang, Yi; Dryer, Frederick L.

doi:10.1016/j.fuel.2013.07.105

Cited by 255 publications

(248 citation statements)

References 35 publications

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“…Ethanol has a greater research octane number and motor octane number than commercial gasoline blends and blending of ethanol and commercial gasoline increases the fuel octane rating and allows a greater compression ratio [16]. The larger enthalpy of vaporization, viscosity and surface tension of ethanol likely yields greater droplet sizes than for primary reference fuels or gasoline as indicated by the hollow cone spray measurements of several fuels [17].…”

Section: Ethanolmentioning

confidence: 99%

In cylinder visualization of stratified combustion of E85 and main sources of soot formation

Johansen

Hemdal

2015

Fuel

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The combustion process and soot formation in spark ignited spray guided stratified combustion of E85 was investigated in a single cylinder optical engine with direct injection of fuel using an outward opening piezo actuated injector. The effect of engine rotation frequency, fuel quantity, injection sequence and ignition timing was studied. Combustion, soot formation and soot oxidation was analysed using cylinder pressure measurements, images recorded using high speed video cameras, the flame emission spectrum and OH * chemiluminescence and soot incandescence imaging. A maximum injection duration was found to exist for direct ignition of the fuel spray. Engine rotation frequency had little effect on the initial and maximum rate of combustion. The maximum rate of combustion decreased with increasing cycle fuel mass when a single injection was used. The rate of combustion and indicated mean effective pressure increased and the combustion variability decreased when the single injection was split into multiple injections in close succession to deliver the same total fuel mass and the last fuel spray was ignited. Ignition of the first fuel spray resulted in a more pronounced change. The absence of soot incandescence during the initial flame propagation suggested flame propagation in a partially mixed fuel and air mixture with stoichiometric to fuel lean regions. A single fuel injection resulted in piston pool fires due to fuel spray impingement on the piston and was the primary source of soot formation. The pool fires persisted until after conditions favourable to oxidation of the soot had ended. Soot formation in the gas phase occurred while favourable soot oxidation conditions existed and was efficiently oxidized. The magnitude of the piston pool fires was reduced using multiple injections. The reduction is attributed to a reduction of the fuel spray penetration length and a smaller effective injection orifice area, resulting in a shorter total duration of fuel spray impingement on the piston crown. Soot formation occurred primarily in the gas phase when the first of two fuel sprays was ignited and persisted due to the second fuel spray entering an existing flame leading to fuel rich combustion.

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Section: Ethanolmentioning

confidence: 99%

In cylinder visualization of stratified combustion of E85 and main sources of soot formation

Johansen

Hemdal

2015

Fuel

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“…Heavy alcohols have high energy contents and blend well with traditional fuels. Isooctane is identified as the representative branched paraffin and, hence an important constituent in the surrogates of traditional fuels [9][10][11], therefore, investigating alcohol-isooctane blends can provide valuable information for understanding the potential of alcohols as alternative fuels.…”

Section: Introductionmentioning

confidence: 99%

Laminar Flame Characteristics of C1–C5 Primary Alcohol-Isooctane Blends at Elevated Temperature

Jin

Huang

2016

Energies

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Abstract:The laminar combustion characteristics of blends of isooctane and C1-C5 primary alcohols (i.e., methanol, ethanol, n-propanol, n-butanol and n-pentanol) were investigated using the spherical expanding flame methodology in a constant volume chamber at various equivalence ratios and volume fractions of alcohol. The stretch effect was removed using the nonlinear methodology. The results indicate that the laminar flame speeds of alcohol-isooctane blends increase monotonously with the increasing volume fraction of alcohol. Among the five alcohols, the addition of methanol is identified to be the most effective in enhancing laminar flame speed. The addition of ethanol results in an approximately equivalent laminar flame speed enhancement rate as those of n-propanol, n-butanol and n-pentanol at ratios of 0.8 and 1.5, and a higher rate at 1.0 and 1.2. An empirical correlation is provided to describe the laminar flame speed variation with the volume fraction of alcohol. Meanwhile, the laminar flame speed increases with the mass content of oxygen in the fuel blends. At the equivalence ratio of 0.8 and fixed oxygen content, similar laminar flame speeds are observed with different alcohols blended into isooctane. Nevertheless, with the increase of equivalence ratio, heavier alcohol-isooctane blends tend to exhibit higher values. Markstein lengths of alcohol-isooctane blends decrease with the addition of alcohol into isooctane at 0.8, 1.0 and 1.2, however they increase at 1.5. This is consistent with the behavior deduced from the Schlieren images.

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“…E-mail address: sibel_o@yahoo.ro [5][6][7], but there is a lack of research on gasoline+propanol or butanol blends [5,8].…”

Section: Introductionmentioning

confidence: 99%

Study of the refractive index of gasoline+alcohol pseudo-binary mixtures

Nita

Geacai

Iulian

et al. 2017

Ovidius University Annals of Chemistry

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Abstract. The properties of gasoline change as a result of blending with a bioalcohol, affecting the behavior of the pseudo-binary system. The aim of this paper is to present experimental data of the refractive index for pseudobinary mixtures of a reformate gasoline with ethanol, isopropanol and n-butanol over the entire composition range and for temperature ranging from 293.15 K to 313.15 K. The accuracy of different equations to predict the refractive index of the mixtures was tested. The best prediction accuracy (the lower AAD) corresponded to Eykman and Lorentz-Lorenz mixing rules. A logarithmic equation proposed to correlate the refractive index with composition and temperature of gasoline+alcohol mixtures showed a good accuracy (the absolute average deviation AAD < 0.052%). The deviations in refractive index for investigated systems are negative over the entire composition range and at all investigated temperatures.

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The octane numbers of ethanol blended with gasoline and its surrogates

Cited by 255 publications

References 35 publications

In cylinder visualization of stratified combustion of E85 and main sources of soot formation

In cylinder visualization of stratified combustion of E85 and main sources of soot formation

Laminar Flame Characteristics of C1–C5 Primary Alcohol-Isooctane Blends at Elevated Temperature

Study of the refractive index of gasoline+alcohol pseudo-binary mixtures

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