Experimental Evaluation of Oil Extraction from South African Melia azedarach Seeds as Feedstock for Biodiesel Synthesis

Abstract

Global increase in fuel prices and the associated problem of harmful emissions from combustion of fossil fuels has necessitated the need for more energy sources to sustain energy security and mitigate the negative environmental implications from the continuous use of petroleum diesel. This research is primarily focused on the production of biodiesel from Melia azedarach oil, which has not been much explored as a feedstock for diesel substitute. In consideration of the nutritional demands for edible oil seeds, the use of edible vegetable stock to produce biodiesel raises major ethical concerns with non-edible oil seeds presenting more feasible solution to energy crises. Oil was extracted from Melia azedarach seeds by exploring both mechanical and chemical methods. Biodiesel was produced from the extracted oil via alkali alcoholysis. An innovative Ultraviolet-Visible Spectroscopy (UV-VIS) was adopted as a process tracking mechanism for biodiesel production. An oil yield of 4.32% of crude oil was extracted using n-hexane under an extraction time of 24h and temperature of 55°C. Esterification parameters of 45:1 Molar concentration of alcohol to oil, reaction temperature of 53°C, a reaction time of 50 mins and concentrated sulphuric acid weight fraction of 5% gave a free fatty acid conversion of 89.37%. Based on the results obtained, the seed oil has been established as a promising feedstock with promising efficiency for biodiesel production. However, large scale extraction of oil from the seed for industrial production of biodiesel must be further investigated.