Wang (2024) Biodiesel production from spent coffee grounds utilizing pomegranate/orange peel biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More as a green and renewable nanocatalyst: Compression ignition engine performance and emission. Industrial Crops and Products. https://doi.org/10.1016/j.indcrop.2024.118890

Researchers have developed a green and renewable nanocatalyst from pomegranate and orange peels to convert spent coffee grounds (SCG) oil into biodiesel, achieving a remarkable efficiency of 95.24% under optimal conditions. This novel catalyst, called POPAC, demonstrated significant recyclability, maintaining 87.43% efficiency even after seven uses. The biodiesel produced meets ASTM standards, indicating high quality. Adding SCG-derived biodiesel to diesel fuel improved engine performance and reduced harmful emissions like CO, CO2, and unburned hydrocarbons.

The study involved extensive characterization of the POPAC catalyst using various techniques to ensure its effectiveness. Ultrasonication played a key role in the biodiesel production process, making it faster and more efficient. The kinetic analysis showed that the biodiesel synthesis process is endothermic and benefits from higher temperatures.

The research highlights the potential of using agricultural waste, like coffee grounds and fruit peels, for biodiesel production, offering an eco-friendly and cost-effective alternative to conventional fuels. This approach not only addresses waste disposal issues but also contributes to the development of sustainable energy sources. The findings suggest that POPAC green nanocatalysts could play a crucial role in future biodiesel production, combining environmental benefits with economic viability.