Optimization of Base-Catalyzed Transesterification toward Maximum Biodiesel Yield from Camelus dromedarius Fat Waste

Abstract

Utilization of organic waste offers a promising pathway to advance the circular bioeconomy and address global energy challenges through sustainable biodiesel production. Camelus dromedarius fat waste, abundant in arid and semiarid regions, remains an underexploited byproduct with considerable potential as a renewable biodiesel feedstock, reducing dependence on conventional resources. Despite significant progress in biodiesel research, studies on the transesterification of Camelus dromedarius fat waste are limited, and comprehensive optimization of its reaction parameters is lacking. This study evaluated biodiesel production from camel fat waste oil through alkali-catalyzed transesterification and optimized the process using Response Surface Methodology (RSM) based on a Central Composite Design (CCD). For the optimization stage, catalyst concentration (0.25–1.25 wt %), reaction temperature (45–85 °C), reaction time (15–55 min), and oil-to-methanol molar ratio (1:3–1:15) were selected as independent variables to investigate their individual and interactive effects on biodiesel yield. The RSM model predicted a maximum biodiesel yield of 95% under optimal conditions of 68 °C reaction temperature, 0.8 wt % catalyst concentration, 36 min reaction time, and an oil-to-methanol molar ratio of 1:9.6. Validation experiments confirmed the model prediction with an average yield of 94.82% and a relative error of only 0.19%. The produced biodiesel was characterized by FTIR, GC-FID, and physicochemical properties. The fuel properties were largely consistent with ASTM D6751 specifications, while viscosity slightly exceeded the EN 14214 limit and cold-flow properties indicated limited suitability for low-temperature applications. This underscores the potential of discarded camel fat as a sustainable feedstock and demonstrating that optimized transesterification enhances resource efficiency and advances biodiesel technologies within a circular bioeconomy framework.