Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Experimental Determination of Liquefied Petroleum Gas–Gasoline Mixtures Knock Resistance

[+] Author and Article Information
Emiliano Pipitone

Dipartimento di Ingegneria Chimica,
Gestionale, Informatica, Meccanica,
University of Palermo,
Viale delle Scienze,
Palermo 90128, Italy
e-mail: emiliano.pipitone@unipa.it

Giuseppe Genchi

Dipartimento di Ingegneria Chimica,
Gestionale, Informatica, Meccanica,
University of Palermo,
Viale delle Scienze,
Palermo 90128, Italy
e-mail: giuseppe.genchi@unipa.it

The air–fuel mixture portion most distant from ignition point, which undergoes auto-ignition if not promptly reached by the flame front.

The research octane number [32] is another ASTM knock rating method that prescribes the use of a CFR engine under different and less heavy test conditions respect to MON method [11]. For this reason, the RON of a fuel is usually higher than its MON.

1Corresponding author.

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received November 27, 2013; final manuscript received June 5, 2014; published online July 2, 2014. Assoc. Editor: Stani Bohac.

J. Eng. Gas Turbines Power 136(12), 121502 (Jul 02, 2014) (7 pages) Paper No: GTP-13-1432; doi: 10.1115/1.4027831 History: Received November 27, 2013; Revised June 05, 2014

The results of previous experimental researches showed that great advantages can be achieved, both in terms of fuel consumption and pollutant emissions, in bifuel vehicles by means of the double-fuel combustion, i.e., the simultaneous combustion of gasoline and a gaseous fuel, such as liquefied petroleum gas (LPG) or natural gas (NG). The substantial increase in knock resistance pursued by adding LPG to gasoline, which allowed to maintain an overall stoichiometric proportion with air also at full load, is not documented in the scientific literature and induced the authors to perform a proper experimental campaign. The motor octane number (MON) of LPG–gasoline mixtures has been hence determined on a standard cooperative fuel research (CFR) engine, equipped with a double-fuel injection system in order to realize different proportions between the two fuels and electronically control the overall air–fuels mixture. The results of the measurement show a quadratic dependence of the MON of the mixture as function of the LPG concentration evaluated on a mass basis, with higher increase for the lower LPG content. A good linear relation, instead, has been determined on the basis of the evaluated LPG molar fraction. The simultaneous combustion of LPG and gasoline may become a third operative mode of bifuel vehicles, allowing to optimize fuel economy, performances, and pollutant emissions; turbocharged bifuel engines could strongly take advantage of the knock resistance of the fuels mixture thus adopting high compression ratio (CR) both in pure gas and double-fuel mode, hence maximizing performance and reducing engine size. The two correlations determined in this work, hence, can be useful for the design of future bifuel engines running with knock safe simultaneous combustion of LPG and gasoline.

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Pipitone, E., and Beccari, S., 2010, “Performance and Emission Improvement of a S.I. Engine Fuelled by LPG/Gasoline Mixtures,” SAE Technical Paper No. 2010-01-0615. [CrossRef]
Pipitone, E., and Beccari, S., 2009, “Performances Improvement of a S.I. CNG Bi-Fuel Engine by Means of Double-Fuel Injection,” SAE Paper No. 2009-24-0058. [CrossRef]
Linvengood, J. C., and Wu, P. C., 1955, “Correlation of Autoignition Phenomenon in Internal Combustion Engines and Rapid Compression Machines,” Symp. (Int.) Combust., 5(1), pp. 347–356. [CrossRef]
Douaud, A. M., and Eyzat, P., 1978, “Four-Octane-Number Method for Predicting the Anti-Knock Behavior of Fuels and Engines,” SAE Technical Paper No. 780080. [CrossRef]
Moses, E., Yarin, A. L., and Bar-Yoseph, P., 1995, “On Knocking Prediction in Spark Ignition Engines,” Combust. Flame, 101(3), pp. 239–261. [CrossRef]
Pipitone, E., and Beccari, S., 2009, “Calibration of a Knock Prediction Model for the Combustion of Gasoline-Natural Gas Mixtures,” ASME Paper No. ICEF2009-14057. [CrossRef]
Radu, B., Martin, G., Chiriac, R., and Apostolescu, N., 2005, “On the Knock Characteristics of LPG in a Spark Ignition Engine,” SAE Paper No. 2005-01-3773. [CrossRef]
Radu, B., and Fuiorescu, D., 2010, “About the Thermal Effect of Pre-Knock Reactions in a Spark Ignition Engine Fueled With LPG,” SAE Paper No. 2010-01-2264. [CrossRef]
Morganti, K. J., Foonga, T. M., Breara, M. J., da Silvab, G., Yanga, Y., and Dryerc, F. L., 2013, “The Research and Motor Octane Numbers of Liquefied Petroleum Gas (LPG),” Fuel, 108, pp. 797–811. [CrossRef]
Boldt, K., 1967, “Motor (LP) Knock Test Method Development,” SAE Technical Paper No. 670055. [CrossRef]
ASTM, 2007, “Standard Practice for Calculation of Certain Physical Properties of Liquefied Petroleum (LP) Gases From Compositional Analysis,” ASTM International, West Conshohocken, PA, Standard No. D2598.
ASTM, 2011, “Standard Specification for Liquefied Petroleum (LP) Gases,” ASTM International, West Conshohocken, PA, Standard No. D1835.
Department of Environment and Heritage, Commonwealth of Australia, 2001, “Setting National Fuel Quality Standards, Paper 5, Proposed Standards for Liquefied Petroleum Gas,” CCP Instant Printing, Canberra, Australia.
Technical Committee CEN/TC 19, 2004, “Automotive Fuels—LPG—Requirements and Test Methods Designation,” European Committee for Standardization, Brussels, Belgium, Paper No. BS EN 589:2004.
Lee, S., Oh, S., and Choi, Y., 2009, “Performance and Emission Characteristics of an SI Engine Operated With DME Blended LPG Fuel,” Fuel, 88(6), pp. 1009–1015. [CrossRef]
Oh, C., Jang, J., and Bae, C., 2010, “The Effect of LPG Composition on Combustion and Performance in a DME-LPG Dual-Fuel HCCI Engine,” SAE Technical Paper No. 2010-01-0336. [CrossRef]
Jian, D., Xiaohong, G., Gesheng, L., and Xintang, Z., 2001, “Study on Diesel-LPG Dual Fuel Engines,” SAE Technical Paper No. 2001-01-3679. [CrossRef]
Hashimoto, K., Ohta, H., Hirasawa, T., Arai, M., and Tamura, M., 2002, “Evaluation of Ignition Quality of LPG With Cetane Number Improver,” SAE Technical Paper No. 2002-01-0870. [CrossRef]
Anderson, J. E., Di Cicco, D. M., Ginder, J. M., Kramer, U., Leone, T. G., Raney-Pablo, H. E., and Wallington, T. J., 2012, “High Octane Number Ethanol-Gasoline Blends: Quantifying the Potential Benefits in the United States,” Fuel, 97, pp. 585–594. [CrossRef]
ASTM, 2011, “Standard Test Method for Motor Octane Number of Spark-Ignition Engine Fuel,” ASTM International, West Conshohocken, PA, Standard No. D2700.
Attar, A. A., and Karim, G. A., 2003, “Knock Rating of Gaseous Fuels,” ASME J. Gas Turbine Power, 125(2), pp. 500–504. [CrossRef]
Rahmouni, C., Brecq, G., Tazerout, M., and Le Corre, O., 2004, “Knock Rating of Gaseous Fuels in a Single Cylinder Spark Ignition Engine,” Fuel, 83(3), pp. 327–336. [CrossRef]
Kubesh, J., King, S., and Liss, W., 1992, “Effect of Gas Composition on Octane Number of Natural Gas Fuels,” SAE Technical Paper No. 922359. [CrossRef]
Myers, M. E., Jr., Stollstelmer, J., and Wims, A. M., 1975, “Determination of Hydrocarbon-Type Distribution and Hydrogen/Carbon Ratio of Gasolines by Nuclear Magnetic Resonance Spectrometry,” Anal. Chem., 47(12), pp. 2010–2015. [CrossRef]
Boundy, B., Diegel, S. W., Wright, L., and Davis, S. C., 2011, Biomass Energy Data Book, 4th ed., U.S. Department of Energy, Oak Ridge National Laboratory, Oak Ridge, TN, Paper No. ORNL/TM-2011/446.
Anderson, J. E., Kramer, U., Mueller, S. A., and Wallington, T. J., 2010, “Octane Numbers of Ethanol- and Methanol-Gasoline Blends Estimated From Molar Concentrations,” Energy Fuels, 24(12), pp. 6576–6585. [CrossRef]
API, 1988, Alcohols and Ethers, 2nd ed., American Petroleum Institute, Washington, DC, Publication No. 4261.
Lanje, A. S., and Deshmukh, M. J., 2012, “Performance and Emission Characteristics of SI Engine Using LPG-Ethanol: A Review,” Int. J. Emerg. Technol. Adv. Eng., 2(10), pp. 146–152.
Nikolaou, N., Papadopoulos, C. E., Gaglias, I. A., and Pitarakis, K. G., 2004, “A New Non-Linear Calculation Method of Isomerisation Gasoline Research Octane Number Based on Gas Chromatographic Data,” Fuel, 83(4–5), pp. 517–523. [CrossRef]
Kukkadapu, G., Kumar, K., Sung, C.-J., Mehl, M., and Pitz, W. J., 2012, “Experimental and Surrogate Modeling Study of Gasoline Ignition in a Rapid Compression Machine,” Combust. Flame, 159(10), pp. 3066–3078. [CrossRef]
Prince, J. C., and Williams, F. A., 2012, “Short Chemical-Kinetic Mechanisms for Low-Temperature Ignition of Propane and Ethane,” Combust. Flame, 159(7), pp. 2336–2344. [CrossRef]
ASTM, 2011, “Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel,” ASTM International, West Conshohocken, PA, Standard No. D2699.


Grahic Jump Location
Fig. 1

Raw CO emission measured at WOT for pure gasoline (same λ values of Fig. 1) and double-fuel mode (λ = 1) on a series production S.I. engine [1]

Grahic Jump Location
Fig. 2

HC emissions after catalytic converter at WOT for both pure gasoline mode (λ values reported on the right axis) and double-fuel mode (λ = 1) on a series production S.I. engine [1]

Grahic Jump Location
Fig. 3

CFR engine combustion chamber: the knock sensor is placed on the opposite side to the spark plug

Grahic Jump Location
Fig. 4

Experimental system layout

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Fig. 5

Fuel supply systems: carburettor, LPG injector, and gasoline injector

Grahic Jump Location
Fig. 6

Scheme of the injection system

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Fig. 7

Measured MON as function of the LPG mass fraction

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Fig. 8

Measured MON as function of the LPG molar fraction

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Fig. 9

Engine CR and spark advance adopted in the tests



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