Selection of low price and non-edible feedstocks for biodiesel production is a considerable target to diminish the production cost of biodiesel. Accordingly, the current work is to inspect the production of fatty acid ethyl esters (ethylic biodiesel) from mixed non-edible oils particularly; castor oil seeds (CSO) and bitter almond oil (BAO). Various blends of the CSO: BAO (10:90 -50:50 % w/w) were prepared and evaluated in order to choose the optimal blend whose properties similar to those reported for conventional raw oils. The results indicate that the equivalent blend (50:50 % w/w) possess the optimal properties. Therefore, it was chosen as a raw feedstock for producing ethylic biodiesel through the standard base-catalyzed transesterification process by using KOH as a catalyst with ethanol. Experimental parameters affecting transesterification process, such as the type and the concentration of the alkali catalyst, ethanol to mixed oils molar ratio, the reaction temperature, and the reaction time were optimized. Biodiesel with maximum yield (98.88 wt. % with purity of 97.66 % w/w) was obtained by implementing 0.50 % KOH w/w of oil, 5:1 ethanol to oil molar ratio, 35 °C reaction temperature and 30 minutes time. The 1HNMR spectroscopy affirmed the transformation of the oils blend to ethylic biodiesel. The obtained ethylic biodiesel had density and kinematic viscosity values much lower than those of ethylic biodiesel produced from CSO individually. Furthermore, the properties of the resulting biodiesel were within the acceptable limits prescribed by ASTM D 6751. It was concluded that using such blend oils could be an easy approach to improve the properties of produced biodiesel from castor oil, and to reduce production cost.
Mixed non-edible oils, Ethylic biodiesel, Transesterification, Fuel properties evaluation, Analysis of biodiesel