Experimental study of gasoline-ethanol-hydrogen blends combustion in an SI engine Selahaddin Orhan Akansu a,* , Selim Tang € oz b , Nafiz Kahraman a , Mehmet _ Ilhan _ Ilhak a , Salih Ac ¸ıkg € oz a a Dept. of Mechanical Engineering, Erciyes University Engineering Faculty, Kayseri, Turkey b Dept. of Airframe and Powerplant, Erciyes University Aeronautics and Astronautics Faculty, Kayseri, Turkey article info Article history: Received 31 December 2016 Received in revised form 28 May 2017 Accepted 3 July 2017 Available online xxx Keywords: Gasoline-ethanol-hydrogen com- bustion Internal combustion engine abstract This study presents experimental results of engine performance, combustion and emis- sions in an SI engine fueled by gasoline-ethanol-hydrogen blends. In the experimental studies, engine performance and emission values were analyzed fueled by gasoline, gasoline-ethanol and gasoline-ethanol-hydrogen blends, respectively. When ethanol has been added volumetrically to gasoline 20% of ethanol (G80E20), engine performance and emissions have been worsened. However, the engine performance and emission values have been improved with the adding of hydrogen to blend. The results showed that the addition of hydrogen to the gasoline-ethanol blend improved the combustion process and improved the combustion efficiency, expanded the combustibility range of the gasoline- ethanol blend, reduced emissions. But, nitrogen oxide emission values increased with the adding of hydrogen. © 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction The energy demands have been doubled in the last decade, while the current energy sources would not meet the request of market. For this reason, many researchers have focused on clean and renewable energy with the higher efficiency from each resource [1]. The researches carried out about on clean or renewable alternative fuels for transportation (such as elec- tricity, hydrogen, liquid biofuels, natural gas and bio methane, synthetic fuels and paraffinic fuels and liquefied petroleum gas) have an important place in the research field due to the limited fossil fuel resources and the environmental conditions [2,3]. Ethanol can be obtained from renewable sources such as biomass and agricultural feedstock, so ethanol has been used widely as alternative fuel in SI engines [3]. Moreover, the flame speed of ethanol is higher than that of gasoline and the high octane number of ethanol lets the using of an SI engine having a higher compression ratio [4,5]. Due to ethanol has hydroxyl group, it permits the fast combustion [6]. In addition, ethanol burns cleaner than gasoline and produce less CO and NO X [7,8]. Ethanol fuel has high vaporization heat, therefore, it reduces the maximum temperature inside cylinder and hence reduces the NOx values and increases the engine power [8,9]. Although, ethanol has many good properties which help enhance the combustion, the using of ethanol in SI engines is still limited by its high latent heat and low energy density. However, the high latent heat of ethanol leads to an increase in the volumetric efficiency due to cooling effect which is a main barrier to its commercialization [10,11]. Moreover, ethanol has low diffusivity and shows ignition difficulty at low * Corresponding author. E-mail address: akansu@erciyes.edu.tr (S.O. Akansu). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2017) 1 e10 http://dx.doi.org/10.1016/j.ijhydene.2017.07.014 0360-3199/© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Akansu SO, et al., Experimental study of gasoline-ethanol-hydrogen blends combustion in an SI engine, International Journal of Hydrogen Energy (2017), http://dx.doi.org/10.1016/j.ijhydene.2017.07.014