Comparative Investigation of Prosopis Africana Seed Oil as a Biodiesel and Edible Oil

Prosopis Africana Seed Oil as a Biodiesel and Edible Oil

Abstract

The global and urgent need for alternative and renewable energies to fossil fuels has necessitated this study.
The use of African Mesquite (Prosopis Africana) seed oil as biodiesel and edible oil was investigated. The
seed was subjected to soxhlet extraction using petroleum ether (60 – 80^oC) as a solvent and mechanical
expression to extract its oil. The oil yields of 18% and 23.6% were obtained respectively from the two
processes. The clear, golden-yellow and transparent liquid (oil extract) was subjected to chemo-physical and
thermal analysis to ascertain its composition in the raw state. A stimulated distillation using a GC-MS
analyzer gave a 95% stable yield of diesel at the temperature range of 325 – 330^oC. The products were made
up of alkanes, alkenes, aromatics and carboxylic acids members ranging from 10 to 20. The distillation curve
displays the trend of yields with temperature. The fatty acid profile from the GC-MS analyzer showed that the
oil has 63% linolenic acid with 0.08% free fatty acids. From the results, the oil favourably compares with
NAFDAC’s specifications for edible oils and also presents great potentials for biodiesel when transesterified
or thermally cracked. Based on the oil composition and prospects for biodiesel, an ASTM distillation
apparatus was used to thermally pyrolyze it to produce biodiesel.