Comparison of Performance and Combustion Parameters in a Heavy-Duty Diesel Engine Fueled with Iso-Butanol/Diesel Fuel Blends

Abstract

This study discusses the suitability of iso-butanol/diesel fuel blends as an alternative fuel and determines their effects on the performance and combustion characteristics of a heavy-duty diesel engine. For this purpose, various isobutanol/diesel fuel blends containing 5%, 10% and 15% iso-butanol were prepared in volume basis and tested in a turbo-charged, six-cylinder direct injection diesel engine at the speed of 1400 rpm and three different loads (150, 300 and 450 Nm). The results indicate that when the test engine was fueled with the iso-butanol/diesel fuel blends, the brake thermal efficiency decreased, while the brake specific fuel consumption increased with proportion to using conventional diesel fuel. When iso-butanol/diesel fuel blends were used, the heat release rate, the peak cylinder gas pressure slightly increased compared to the neat diesel fuel use. Although the iso-butanol/diesel fuel blends have poor performance values at partial engine loads, their fuel properties affected the combustion and injection characteristics. They caused reductions in CO, NO x emissions and smoke opacity. However, unburned HC emission slightly increased.Keywords: Iso-butanol, Diesel engine, Performance, Combustion, Eemission NOMENCLATURE ATDC after top dead center CA crank angle ISB10 10% iso-butanol -95% diesel fuel ISB15 15% iso-butanol -95% diesel fuel ISB5 5% iso-butanol -95% diesel fuel INTRODUCTIONIn the last two decades, there is a progressive interest on the alternative fuel use in vehicles due to the impact of the transportation sector on greenhouse gases and human health, and limited petroleum sources. Bio-fuels (methanol, ethanol, etc.) have been shown good candidates as alternative fuels for vehicles because they are liquid, and have several physical and combustion properties similar to gasoline and diesel fuel (Reijnders, 2006; Demirbas, 2007;Qin et al., 2009;Saydut et al., 2011). Alcohols have higher octane number and oxygen content. Thus, combustion of alcohols in gasoline engines show better results compared to pure gasoline. However, there have been some difficulties (ignition problem etc.) related to the use of alcohol fuel in diesel engines because of their low cetane number, high latent heat of vaporization and long ignition delay. With the aim of overcoming these problems, different methods such as alcohol fumigation, dual injection, alcohol-diesel fuel blend and alcohol-diesel fuel emulsion can be utilized (Agarwal, 2007;Riberio et al., 2007).The most attractive feature of iso-butanol is its energy content which is higher than other alcohols such as methanol, ethanol, etc. The energy content of iso-butanol is 21% less than diesel fuel. Iso-butanol has higher density than other alcohols such as ethanol and methanol etc. The density of iso-butanol improves its energy density. Another important feature of iso-butanol is less sensitivity to water than ethanol, which tends to settle in layers when water is present (Lebedevas et al., 2010). The stoichiometric airfuel ratio of iso-butanol is low...

A comparative evaluation and optimization of performance and emission characteristics of a DI diesel engine fueled with n-propanol/diesel, n-butanol/diesel and n-pentanol/diesel blends using response surface methodology

“…High latent heat of vaporization causes poorer and slower fuel-air mixing that can increase NOx emissions. 49 Thus HC emissions clearly follow the order of cetane index and latent heat of vaporization of the blends as follows (from highest to lowest): n-propanol/diesel > n-butanol/diesel > n-pentanol/diesel blend at bmep = 4.0 bar and speed = 1500 rpm.…”

Effect of exhaust gas recirculation (EGR) on performance and emissions of a constant speed DI diesel engine fueled with pentanol/diesel blends

“…72 Further the less calorific value, poor miscibility and instability dur-73 ing blending, poor lubricating properties challenge their use in die-74 sel engines [5]. Several have been used to overcome these shortcomings of alcohols as a 77 diesel engine fuel [6]. The use of higher alcohols in diesel engines 78 has gained interest in the recent years with the focus especially 79 on butanol and its isomers [3][4][5][6][7][8][9].…”

“…Several have been used to overcome these shortcomings of alcohols as a 77 diesel engine fuel [6]. The use of higher alcohols in diesel engines 78 has gained interest in the recent years with the focus especially 79 on butanol and its isomers [3][4][5][6][7][8][9]. Their results showed that buta-80 nol-diesel blends have significantly reduced soot and CO emissions 81 with slight impact in performance.…”

Analysis of Regulated Pollutant Emissions and Aftertreatment Efficiency in a GTDi Engine Using Different SOI Strategies

“…Other factors that also have great influence on the NOx formation are the residence time for the reaction and also the oxygen concentration [63,64]. Figure 9C shows a reduction in raw NOx emissions with the SOI delay in both operating points.…”