Influence of fuel mixture on the performance of K/Ca–Al catalyst synthesized via solution combustion method for Microwave-Assisted biodiesel Production: Optimization study via RSM

چکیده مقاله

Calcium aluminate supported by KOH was synthesized via urea-nitrate combustion method where sorbitol was utilized as an auxiliary fuel. Sorbitol, a polyol with high oxygen and carbon content, promotes combustion temperature and released gaseous from the combustion medium which can directly influence on textural properties and crystallinity. The synthesized catalysts were utilized for microwave-assisted biodiesel production. The inclusion of sorbitol enhanced surface area (12.9 m²/g), pore volume (0.119 cc/g), mean pore diameter (8.8 nm) and crystallinity of the catalyst, resulting in improved catalytic activity. The optimal catalyst with the highest activity in microwave-assisted biodiesel production from canola oil was obtained at urea-sorbitol ratio of 1:0.25. The optimization of transesterification conditions was performed using Response Surface Methodology (RSM) via optimal catalyst where the maximum yield of 94.9 %, with an experimental yield of 93.8 %, was achieved. The reusability of the catalyst was evaluated at the optimum transesterification conditions of 450 W of microwave power, methanol/oil molar ratio of 14.3, catalyst amount of 4.5 wt% and 51 min of reaction time, showing only a 14 % reduction in biodiesel yield after six cycles. These results highlight the potential of sorbitol-assisted synthesis for sustainable catalyst development and the ability of K/Ca-Al mixed metal oxides, as effective catalyst, for biodiesel production.