Experimental study on the performance and emission measures of direct injection diesel engine with Kapok methyl ester and its blends

• Kapok biodiesel is derived by acid and alkaline catalyzed esterification method.
• Lean blends of Kapok biodiesel B20 and B40 are performing even better than diesel.
• CO and HC emissions are reduced up to B60, Smoke is reduced 22%.
• Kapok biodiesel proved its suitability to be an alternate to diesel.

In this study, Kapok methyl ester was derived from Kapok seed oil by the two-step esterification process. The two-step process consists of acid-catalyzed pretreatment, followed by alkaline-catalyzed transesterification. The experimental investigation was carried out in a single-cylinder direct injection diesel engine, and the performance and exhaust emissions of the engine were also studied for the different blends of Kapok methyl ester. The results showed that the exhaust gas temperature and specific fuel consumption are increased for rich blends of Kapok methyl ester, but the brake thermal efficiency is decreased for the same blends. The NOx emission is higher than that of diesel at all load conditions of the engine. The lean blend of the Kapok methyl ester has appreciable engine efficiencies, lower values of smoke, and lower CO and HC emissions. Thus, the experimental results proved that the Kapok methyl ester is one of the most suitable alternatives to diesel fuel.