Experimental investigation on the combustion and emissions characteristics of 2-methylfuran gasoline blend fuel in spark-ignition engine Haiqiao Wei a,⇑ , Dengquan Feng a , Gequn Shu a , Mingzhang Pan a , Yubin Guo b , Dongzhi Gao a , Wei Li c a State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China b Yunnan Key Laboratory of Internal Combustion Engine, Kunming University of Science and Technology, Kunming, Yunnan 650500, China c School of Architecture, Tianjin Chengjian University, Tianjin 300384, China highlights  2-Methylfuran gasoline blend and ethanol gasoline blend were compared in a SI engine.  Combustion duration, thermal efficiency and regulated emissions were studied.  Compared with E10, BSFC and COV of IMEP can be improved by M10 blend.  M10 are similar to E10 and superior to gasoline in terms of HC and CO emissions.  NO X emissions increase is found by using M10 blend fuel. article info Article history: Received 20 January 2014 Received in revised form 7 April 2014 Accepted 4 July 2014 Available online 31 July 2014 Keywords: 2-Methylfuran Ethanol Blend fuel Emissions SI engines abstract Currently, 2,5-dimethylfuran (DMF) has already been extensively studied as a novel potential gasoline substitute. With its improved reaction sequences, another main molecule transformed from fructose has also aroused worldwide interest, which is known as 2-methylfuran (MF). MF has similar energy den- sity and knock suppression ability to DMF. However, little is known about its behavior in spark-ignition (SI) engines, especially when it is used as a gasoline additive. Therefore, focus was given on the combus- tion and emissions characteristics of 10% volume fraction 2-methylfuran gasoline blend fuel (M10) in this work, which was investigated experimentally in a single-cylinder four-stroke SI engine at various engine speeds (800–1800 rpm in 200 rpm intervals) and wide open throttle (WOT). The in-cylinder combustion process as well as engine performance of M10 were compared with gasoline and the same proportion ethanol gasoline blend fuel (E10) under gasoline maximum brake torque (MBT) spark timing and stoichi- ometric air-fuel ratio. Results of engine tests show that M10 produces relatively high in-cylinder peak pressure and temperature, which is mainly attributed to its consistently shorter combustion duration. Compared with engine performance of E10, the output torque and brake power increase slightly with less brake specific fuel consumption when M10 is used. Lower regulated gas emissions of hydrocarbons (HC) and carbon monoxide (CO) can be found for both E10 and M10 blend. In addition, more nitrogen oxides (NO X ) emissions are generated from M10 due to its higher combustion temperature. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Rapid development of industrialization and modernization has led to excessive consumption of petroleum, which is found to be the major source of greenhouse gas (GHG) emissions [1,2]. Today, it is reported that around 62.3% of oil is consumed by transport sector alone [2]. Therefore, it is necessary to search for alternative fuels to reduce the dependency on petroleum-based fuels and to lower GHG emissions. Currently, some substitute fuels have already been used for powering an engine, such as hydrogen, http://dx.doi.org/10.1016/j.apenergy.2014.07.009 0306-2619/Ó 2014 Elsevier Ltd. All rights reserved. Abbreviations: aTDC, after top dead center; bTDC, before top dead center; CA50, crank angle of 50% mass fraction burned; CAD, crank angle degree; CD, combustion duration; CO, carbon monoxide; COV, coefficient of variation; DMF, 2,5-dimethyl- furan; E10, 10% volume blending ratio ethanol gasoline; GHG, greenhouse gas; HC, hydrocarbon; IMEP, net indicated mean effective pressure (calculated over 720 °CA); LHV, lower heating value; M10, 10% volume blending ratio 2-methylfuran gasoline; MF, 2-methylfuran; MFB, mass fraction burned; MON, motor octane number; NO X , oxides of nitrogen; PFI, port-fuelinjection; BSFC, brake specific fuel consumption; SI, spark ignition; RON, research octane number; WOT, wide open throttle. ⇑ Corresponding author. Tel./fax: +86 22 27402609. E-mail address: whq@tju.edu.cn (H. Wei). Applied Energy 132 (2014) 317–324 Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy