Waste-Derived Green Nanocatalyst for Biodiesel Production: Kinetic-Mechanism Deduction and Optimization Studies

This research focuses on deducing the kinetic mechanism for biodiesel production catalyzed by a CaO nanocatalyst derived from waste cockle shells via thermal hydration-dehydration treatment. In addition, the CaO nanocatalyst preparation method via thermal hydration-dehydration-related parameters (hydration duration, recalcination temperature, and recalcination duration) was studied and optimized. The transesterification reaction catalyzed by the CaO nanocatalyst followed the Langmuir-Hinshelwood kinetic mechanism with surface reaction as the rate-limiting step. The relatively low activation energy (3786.7 J/mol) for a transesterification reaction offered by the CaO nanocatalyst enhanced the reaction rate to 27.3% FAME yield/hr. The optimal conditions for the thermal hydration-dehydration treatment used to develop the nano CaO catalyst were 6 h of hydration duration, 650 degrees C of recalcination temperature, and 3 h of recalcination duration. Of biodiesel yield, 94.13% was obtained at a moderate temperature of 60 degrees C and 3 h reaction time during the transesterification of palm oil catalyzed by the nano-CaO. SEM, BET, and TPD results proved that the CaO nanocatalyst had a large surface area (13.9113 m(2)/g) and high pore volume (0.0318 cm(3)/g) that were rich in active sites (1046.46 mu mol CO2/g), and the pore diameter (33.17 nm) was accessible to reactants and products.

Automated summary

The research focuses on developing a kinetic mechanism for biodiesel production catalyzed by a CaO nanocatalyst derived from waste cockle shells via thermal hydration-dehydration treatment. The transesterification reaction follows a Langmuir-Hinshelwood kinetic mechanism with surface reaction as the rate-limiting step, offering a relatively low activation energy and high FAME yield. The optimal conditions for preparing the nano CaO catalyst and conducting transesterification reactions were investigated and demonstrated promising results for potential industrial applications.