African Journal of Biotechnology Research

African Journal of Biotechnology Research ISSN 9316-2194 Vol. 4 (3), pp. 171-178, March, 2016. © International Scholars Journals

Full Length Research Paper

Assessment of almond (Prunus amygdalus) seed oil as a feasible feedstock for biodiesel fuel

Ademola H. E and Adedeji Babatunde

Department of Chemistry, Federal University of Technology, Akure, Ondo State, Nigeria.

E-mail: demola.henry@gmail.com 

Accepted 5 February, 2016

Abstract

Viability of almond (Prunus amygdalus) seed oil as a potential feedstock for biodiesel production was reported. The oil content of the seed was extracted with n-hexane using Soxhlet extraction method. The extracted oil was characterized to determine the key physical and chemical properties that mark the suitability of the oil for biodiesel production. Values obtained for parameters such as density (0.98 g/cm3), flash point (220°C), acid value (40.14 mg/KOH/g) and kinematic viscosity (30 CSt at 40°C) for the extracted oil were comparable with values reported for other non-edible oils such as Jatropha curcas, Pongamina pinnata, Azadirachata indica and Simaroubia indica. The extracted seed oil was transesterified using both homogeneous (NaOH) and heterogeneous (CaO and MgO) catalysts. The yields of biodiesel obtained with homogeneous catalyst under optimum conditions such as 1500 rpm agitation speed, 60°C reaction temperature, 5:1 methanol to oil ratio were relatively higher than the yields obtained with heterogeneous catalyst under these same experimental conditions. Physico-chemical properties of the biodiesel such as acid value (mgKOH/g), saponification value (mg/g), flash point (°C), fire point (°C), specific gravity (gm-3), viscosity (Kgm-1S-1), cloud point (°C) and centane number were determined and found consistent with the standards set for ASTM D6751 and EN 14214. In addition, remarkable variation was noticed in the flash point (298°C) and cetane number (62) of the biodiesel when compared with those of petrol diesel which were 125°C and 49, respectively. Weight percent composition of the biodiesel was 0.49 for diglycol diacetate, 43.04 for methyl oleate, 48.40 for methyl palmitate and 8.07 for methyl stearate. The biodiesel profile of the seed-oil is comparable with the high quality biodiesel produced with yellow oleander (Thevetia peruvian) seed oil. Hence, almond seed oil is cheaper, cleaner and suitable feedstock for biodiesel fuel. 

Key words: Almond seed-oil, catalysts, transesterification, biodiesel, petrol diesel.