Performance, Combustion and Emission Characteristics of a single cylinder 4-Stroke Varying Compression Ratio CI Engine Fueled with Jatropha Biodiesel Blends

Abstract

The Jatropha seed oil is nonedible, contains a high amount of oil, and is a less expensive feedstock. So, in this study, a methyl ester biodiesel was produced from Jatropha seed oil following a two-step transesterification process using methanol, sulfuric acid, and sodium hydroxide. The physical and thermal properties of 20% jatropha-biodiesel and 80% diesel (JB20) were tested on American Society for Testing and Materials (ASTM) standards and found to be within the standard. The effect of jatropha biodiesel blends in different percentage volumes of 10% (JB10), 15% (JB15), and 20% (JB20) and petroleum-based diesel on the performance and emission of four strokes, naturally aspired, water-cooled, and a direct injection diesel engine at five engine loads with a constant engine speed of 1500 rpm at varying compression were examined. The impact of varying compression ratio on the performance and combustion parameters were investigated and analyzed. In this study, different performance parameters of a CI engine fueled with Jatropha biodiesel blends in different percentage volumes of 10% (JB10), 15% (JB15), and 20% (JB20) were tested experimentally. At CR 17, IP of JB20 decreases by 8% at 50% loading, BTE increase by 8%at full load, mechanical efficiency (ME) increases by 8%, SFC increases by 4% while EGT decreases by 2% at full loading condition. At CR17, maximum cylinder pressure, Cumulative heat release, and Net heat release of JB20 decrease by 11.24%, 56.45%, and 4.01% respectively in comparison to diesel. On increasing CR from 15 to 17, JB20 shows a 13% increase in IP, 7.5% increase in ME, SFC decreases by 20%, EGT decreases by 13%, and NHR increases by 22.8% for JB20. The performance and combustion characteristics of Jatropha biodiesel were found to be improved by increasing CR. At low load CO2 emission of diesel is 16% less than JB20 but at full load, diesel shows only 5% less CO2 emission compared to JB20.At low load, HC emission of JB20 decrease by 15% compared to diesel and high load JB20 shows 5% lower HC emission compared to diesel.CO emission of JB20 decrease by 20% at low load while at high load its shows only 6% reduction of CO emission compared to diesel. From the fuel property, engine performance, and emission characteristics, it is concluded that Jatropha biodiesel up to 20% can be blended with diesel and can be used as an alternative fuel in existing diesel engines without any modification.