EXTRACTION AND EVALUATION OF BIO-DIESEL PRODUCED FROM UNDERUTILIZED GLIRICIDIA SEPIUM SEEDS FOR INDUSTRIAL APPLICATION

Abstract

Gliricidia sepium is a small bushy-topped tree, and about 6–8 m high. The tree is pinkish when in flower. It is quick growing and easily propagated by seed or cuttings and it is commonly grown as an ornamental tree in most African communities. G. Sepium is one of the underutilized plants despite its hidden economic potential. Oil from the seeds can be used directly as fuel, or feedstock for producing biodiesel. The present study aimed at extracting oil from G. sepium seeds and evaluating its proximate and physicochemical properties using standard methods. The G. sepium seeds were collected within the campus of Ladoke Akintola University of Technology Ogbomoso, Nigeria and the pods were carefully removed, winnowed, sun-dried, milled and subjected to solvent extraction with Soxhlet apparatus. Petroleum ether was used as the extraction solvent at a temperature of 68°C for 3 h for the 300 g fed into the Soxhlet apparatus. The yield of the G. sepium oil (GSO) obtained is 6.67%. The results of the analysis of the raw seed samples showed high percentages of carbon (44.30%) and oxygen (43.10%). Proximate compositions in GS seeds revealed the moisture content (6.32%), volatile matter (62.83%), fixed carbon content (20.30%), and ash content (10.55%). The result of acid value, Iodine value, FFA, Specific gravity, Refractive Index, Saponification value, and pH were 2.26 mgKOH/g, 29 g/100g, 1.128, 0.87, 1.05, 200 mgKOH/g, and 5.35, respectively. This study has demonstrated that bio-diesel can be produced from underutilized Gliricidia Sepium Seeds for industrial applications particularly in the recent quest for non-edible oil for energy, as required for the Sustainable Development Goal (SDG7).