Transesterification of Bitter Almond Oil as a New Non-edible Feedstock with Mixed Alcohols System: Parameter Optimization and Analysis of Biodiesel

Abstract

The present work reports a successful attempt to produce mixed methyl/ethyl esters from a new non-edible oil feedstock, bitter almond oil. The bitter almond oil was transesterified with different blends of methanol and ethanol (10/90, 20/80, 30/70, 40/60, and 50/50 v/v methanol/ethanol), and the optimal blend percent was found to be (30/70 v/v methanol/ethanol). The other parameters affecting the transesterification reaction of bitter almond oil with the alcohols blend, such as concentration and type of the alkali catalyst, alcohol to oil molar ratio, the reaction temperature, the reaction time, and rate of stirring were, also, optimized. A biodiesel yield of 97.75 wt% with a purity of 97.02 wt% was obtained. Thin layer chromatography was utilized to monitor the alcoholysis of the bitter almond oil to mixed methyl/ethyl esters. The produced biodiesel was analyzed by 1HNMR spectroscopy and the results confirmed the conversion of bitter almond oil to its corresponding methyl/ethyl esters. The fuel properties of the prepared methyl/ethyl esters were measured and found to be within the acceptable limits prescribed by ASTM D 6751. It was concluded that using mixed methanol and ethanol system for transesterification can be used as new alternative method for the production of biodiesel.