Engine Performance and Exhaust Emissions from Sandbox (Hura crepitans) Seed Methyl Ester

Abstract

The finitude and environmental impact of petroleum fuels have led to the search of alternative fuels and biodiesel has proven to be an alternative fuel to petro-diesel with less environmental impact. Engine performance and exhaust emissions of Sandbox Methyl Ester (SBME) fuel were evaluated. Pure SBME (B100) was blended with diesel at 5, 10, 15, 20, 25 and 50% volume designated B5, B10, B15, B20, B25 and B50 respectively. The diesel was used as a reference fuel. The fuel blends (B100-B5) and diesel was used to power a 4-stroke-single-cylinder diesel engine coupled to a dynamometer and a 7.5 kW alternator with varying loads. The brake specific fuel consumption (bsfc), brake power, thermal efficiency, carbon monoxide (CO), oxides of nitrogen (NOx) and hydrocarbon emissions were evaluated. The results of no-load to full-load indicated that diesel utilized the lowest bsfc of 0.14-0.62 kg/kW.h to produce the highest brake power of 5.6-3.7 kW. Similarly, the range of B5-B25 utilized bsfc of 0.16-0.86 kg/kW.h to produce the brake power of 5.1-2.9 kW. The brake thermal efficiency was 58-14% for diesel, and 52-10% for B5-B25. CO emission was reduced to 38.24-11.11% for B5 and 64.71-55.56% for B100. HC emission was reduced to 9.09-5.56% for B5 and 45.45-30.56% for B100. NOx emission increased with SBME concentration. The results obtained for the SBME engine performance and exhaust emissions established it as a potential fuel to power internal combustion engines.