Enhancing biodiesel production from waste date seed oil through ultrasonic-assisted optimization: A sustainable approach using non-edible feedstocks

Abstract

Using non-edible materials as feedstocks in the production of biodiesel is a promising alternative to fossil fuels. Date seed oil (DSO) is an emerging and promising source for biodiesel production owing to its environmental benefits. In this work, ultrasonic-assisted biodiesel production from DSO was investigated using the Box-Behnken design (BBD) approach to optimize the critical reaction variables for a high product yield. A maximum biodiesel yield of 97.3 % was obtained at optimized conditions of 6.1:1 Methanol:DSO ratio, 0.47 wt.% KOH loading, and 52 °C for a batch reaction time of 10 min. Analysis of variance (ANOVA) studies showed that all the input variables and their interaction terms had a significant effect on the biodiesel yield. Further, the predicted quadratic model exhibited a significant correlation with experimental results with a correlation coefficient (R2) value of 0.9897. Kinetic studies showed the superiority of ultrasonics over mechanical stirring for DSO's triglycerides conversion that followed pseudo-first-order kinetics. The physical and chemical properties of the produced biodiesel were closely aligned with ASTM D6751 standards. Thus, the results of this study can be used for the development of biodiesel production from waste date seed oil on a larger scale using the ultrasound-assisted process.