Valorization of indigenous Millettia ferruginea seed oil for biodiesel production: parametric optimization, physicochemical characterization, engine performance and emission characteristics

Abstract

The current investigation aimed to synthesis the biodiesel from an indigenous Millettia ferruginea seed oil (MFO) using methanol with alkali catalyst (NaOH). The factors affecting the oil extraction viz., extraction time, kernel size, solvent: solid, extraction temperature) was optimized via the parametric study. Response surface methodology was utilized to improve the transesterification reaction. The optimum temperature, catalyst concentration, and methanol to oil molar ratio to achieve maximum biodiesel production of 98.1 wt.% were 52.3 °C, 1.3 wt.%, and 8.8:1, respectively. FTIR, NMR, and GC–MS analyses have been used for extracted oil and fatty acid methyl ester (FAME). From the 1H NMR analysis, the conversion of MFO to FAME was 97.5%. Moreover, engine performance and emission characteristics of biodiesel blends and diesel were investigated using a single-cylinder diesel test engine. The specific fuel consumption of biodiesel blends was higher than diesel fuel whereas the thermal efficiencies were found to be lower. The results showed that the blend B5 provided superior performance next to diesel fuel. Besides, the CO and HC emissions of B5 at 80% load condition were 7.28 and 8.56% lesser than diesel, respectively. However, in comparison to diesel, CO2 and NOx emissions were higher for the biodiesel blends.