One-Step Biodiesel Production from Waste Cooking Oil Using CaO Promoted Activated Carbon Catalyst from <i>Prunus persica</i> Seeds

In recent years, the scope for replacing fossil fuels has been appealing to the world, owing to limited conventional fuels, crude oil price volatility, and greenhouse gas emission concerns. In this regard, this article demonstrates the preparation of a novel solid base catalyst for the transesterification of waste cooking oil. A calcium-loaded activated carbon catalyst was prepared through pyrolysis of peach shell followed by chemical activation with KOH and then calcium loading through the wet impregnation method. The prepared catalyst showed the best performance with 20% calcium loading and 650 °C of calcination temperature. The catalyst’s physicochemical, structural, and textural properties were examined using XRD, FTIR, SEM, EDX, and BET analysis. The catalyst showed a maximum yield of 96% at optimized conditions, i.e., 65 °C temperature, oil to methanol ratio 1:8, 5 wt% catalyst concentration, and a 160 min reaction time. Additionally, it illustrated high recyclability up to 10 cycles with negligible leaching of Ca+2 ions. The high activity of the catalyst was due to the presence of calcium ions on the activated carbon support. Physio–chemical properties and GC-MS analysis of prepared biodiesel determined that all attributes were within the biodiesel standard tolerances set by ASTM D6751 and EN 14214. Therefore, all the innovations mentioned above concluded that catalyst generated from peach shell biochar is a promising candidate for biodiesel production, ultimately resulting in solid and liquid waste management