Experimental Investigation of Neat Biodiesels’ Saturation Level on Combustion and Emission Characteristics in a CI Engine

The fuel qualities of several biodiesels containing highly saturated, mono, and poly unsaturated fatty acids, as well their combustion exhaust emission characteristics, were studied. Six biodiesel samples divided into two groups based on acid composition, including group 1 (coconut, castor, jatropha) II (palm, karanja, waste cooking oil biodiesel). All fuels (in both groups) tested in a single-cylinder off-road diesel engine. Castor karanja biodiesel, rich mono-unsaturation level, have high viscosity about 14.5 5.04 mm2/s, respectively. coconut palm are saturation level with cetane numbers 62 60, In groups, saturated poly-unsaturated methyl esters presented better efficiency less formation polluted emissions than mono-unsaturation. At full load, displayed 38% 10% advanced start combustion, respectively, which reduced ignition delay by approximately 3%, Mono-unsaturated exhibited higher cylinder pressure heat release rate, results NOx gas emissions. showed 10–15% lower owing to an optimum composition. Our study concluded that performed mono-unsaturated for engine application.