Microwave energy enhanced oil extraction from Millettia Ferruginea (Birbira) seed for biodiesel application: effects of microwave energy on oil extraction yield

The present study was undertaken to investigate the use of microwave energy for the pretreatment of Millettia ferruginea (Birbira) seed before oil extraction from seed particles. The microwave heating power, microwave heating time, oil seed particle distribution, oil-to-solvent ratio, and oil extraction time were the parameters investigated. The experimental results demonstrated that the maximum oil yield of 54.86 wt.% was exhibited for seed particles treated with microwave energy at 450 W microwave power, 150 s microwave irradiation time, the particles size distribution of below 0.5 mm, 7.5:1 ml/g solvent to seed ratio, and 1.5 h extraction time; while under the same conditions the oil yield of 34.21 wt. % was achieved for microwave energy untreated seed particles. The microstructure of microwave irradiation pretreated and untreated seed particles was investigated. The quantitative 1H nuclear magnetic resonance (NMR) analysis result reveals that the oil composition with 33.57% polyunsaturated, 48.0% monounsaturated, and 18.42% saturated fatty acid. Carbon (13C) and Proton (1H) NMR spectra and Fourier Transform Infrared Spectroscopy (FT-IR) analysis of the extracted oil confirm that the oil contains saturated, monounsaturated, and polyunsaturated fatty acids in its composition. Similarly, the physical and chemical properties of the extracted oil were investigated to observe the suitability of oil for biodiesel production. The results of the present research work show that microwave pretreatment of seed particles enhances the yield of extracted oil and the oil recovered from Millettia Ferruginea (Birbira) is a good non-edible oil candidate for biodiesel production.