Microwave-assisted transesterification for optimized biodiesel production from waste cooking oil using a heterogeneous base catalyst derived from Pila ampullacea shells

Biodiesel production from waste cooking oil (WCO) provides an environmentally friendly solution for reducing fossil fuel dependence while addressing improper oil disposal. This study contributes a targeted optimization strategy for biodiesel synthesis by integrating two specific research initiatives: (1) the application of microwave-assisted transesterification to accelerate reaction kinetics, and (2) the development of a heterogeneous CaO catalyst derived from Pila ampullacea shells with controlled particle-size variation. The effects of these initiatives were systematically evaluated by measuring biodiesel yield and fuel quality under nine treatment combinations of microwave power (80, 240, 400 W) and catalyst particle size (40–60, 60–100,