A Comparative Study of the Impact of the Stirrer Design for Biodiesel Production

Biofuels are becoming more widely recognized as a solution to the energy crisis and reducing dependency on fossil fuels. The cost of raw materials for biodiesel manufacturing is a significant challenge. To improve yield while lowering costs, the process must be optimized. As a result, mixing properties such as stirrer design, blade diameter, and stirrer location were optimized. This study used five blades to evaluate the Stirrer design on biodiesel production: cross stirrer, straight stirrer, blade stirrer, centrifugal stirrer, and pitched blade stirrer. The fluid mixing flow pattern was also examined and analysed. A pitched blade produced the best results, with the biodiesel meeting ASTM requirements. In contrast to the pitched stirrer, the Cross, Blade, and Straight stirrers have radial flow patterns. The centrifugal stirrer's radial and axial flow patterns were difficult to distinguish. Axial flow is essential for transesterification to avoid catalyst deposition at the reactor's bottom. The chosen blade's h/H (blade location from reactor bottom to fluid height) and d/D (blade diameter to reactor diameter) ratios were fine-tuned. The maximum yield was achieved with a h/H of 0.4 and a d/D of 0.3. Using a Pitched blade stirrer with 0.3 d/D and 0.4 h/H, the transesterification reaction yields 98%