ASME Journal of Engineering for Gas Turbines and Power GTP-13-1432, Pipitone, page 1 Experimental determination of LPG-gasoline mixtures knock resistance Emiliano Pipitone 1 University of Palermo Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica Viale delle Scienze, 90128, Palermo, Italy emiliano.pipitone@unipa.it Giuseppe Genchi University of Palermo Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica Viale delle Scienze, 90128, Palermo, Italy giuseppe.genchi@unipa.it ABSTRACT The results of previous experimental researches [1, 2] showed that great advantages can be achieved, both in terms of fuel consumption and pollutant emissions, in bi-fuel vehicles by means of the Double Fuel combustion, i.e. the simultaneous combustion of gasoline and a gaseous fuel, such as LPG or natural gas. 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 of LPG-gasoline mixtures has been hence determined on a standard 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 Motor Octane Number (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 bi-fuel vehicles, allowing to optimize fuel economy, performances and pollutant emissions; turbocharged bi-fuel engines could strongly take advantage of the knock resistance of the fuels mixture thus adopting high compression ratio 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 bi-fuel engines running with knock safe simultaneous combustion of LPG and gasoline. Keywords Octane rating; LPG; gasoline; CFR; fuel mixtures; knock resistance; autoignition. 1 Corresponding author, Tel. +39 091 238 97280. Citing info: Pipitone E. , Genchi G., "Experimental Determination of Liquefied Petroleum Gas– Gasoline Mixtures Knock Resistance", J. Eng. Gas Turbines Power, Vol. 136, Issue 12, doi: 10.1115/1.4027831