Advanced non-catalytic biodiesel production under microwave irradiation using waste cooking oil: Assessment of scale-up potential

The current research explores the utilization of a novel continuous non-catalytic microwave reactor for the conversion of waste cooking oil (WCO) to biodiesel. The process follows the principles of green chemistry by converting WCO into clean fuel under a catalyst-free, energy-efficient approach. By applying the subcritical microwave-assisted technique optimized via response surface methodology, a maximum biodiesel yield of 97.89 ± 0.02 % was observed within 12 min. The cost of production was estimated to be $0.45/L, demonstrating its high potential for commercial-scale application. Kinetic and thermodynamic studies identified pseudo-first-order model, endergonic and nonspontaneous character of the process, respectively. The energy consumption for the overall process was 105 kWh, which demonstrated a low energy requirement, thus confirming the sustainability of the suggested method. Thus, the implementation of the microwave-assisted, non-catalytic, continuous biodiesel production process is an encouraging area of process intensification with a cost-effective route to offset price fluctuations of transportation fuels. The method can be considered for large scale biodiesel production; however, its industrial implementation would demand cautious consideration of pressure management and plant safety.