Performance, Combustion, and Emission Characteristics of a Single-Cylinder Diesel Engine Fuelled with Jatropha Curcas Biodiesel Blends: Experimental Investigation and Comprehensive Literature Assessment

Abstract

Rising fossil fuel prices, depleting crude oil reserves, and tightening vehicular emission norms have collectively intensified the global search for viable alternative fuels for compression ignition (CI) engines. Among the wide spectrum of candidate fuels investigated in the last two decades, biodiesel derived from non-edible oil-bearing plants has emerged as one of the most technically mature and immediately deployable alternatives. Jatropha curcas Linn., a drought-resistant non-edible oilseed crop that thrives on marginal and wasteland soils, has attracted sustained attention as a biodiesel feedstock particularly relevant to the Indian and South Asian context, where large tracts of degraded land are available for energy crop cultivation without competing with food agriculture. This paper presents a systematic experimental investigation into the performance, combustion, and emission characteristics of a single-cylinder, water-cooled, naturally aspirated diesel engine fuelled with blends of Jatropha curcas methyl ester (JCME) at 20 percent (B20) and 40 percent (B40) by volume with neat diesel, covering the full engine load range at a constant speed of 1500 rpm. Fuel properties were characterised and compared with diesel fuel and relevant ASTM standards. Results show that B20 and B40 blends reduce brake thermal efficiency by 1.9 and 4.7 percent respectively relative to diesel, while simultaneously reducing CO emissions by 25.0 and 42.7 percent, HC emissions by 20.8 and 37.5 percent, and smoke opacity by 14.9 and 30.6 percent at full load. NOx emissions increase by 5.3 and 10.7 percent for B20 and B40 respectively, attributable to the higher oxygen content and elevated combustion temperatures associated with biodiesel combustion. The paper also provides a comprehensive critical review of relevant published literature spanning 2000 to 2025, situating the experimental results within the broader research landscape and highlighting unresolved challenges in Jatropha biodiesel deployment at scale in India