A novel Citrus sinensis peel ash coated magnetic nanoparticles as an easily recoverable solid catalyst for biodiesel production

A magnetic nano-sized solid catalyst derived from bio-waste Citrus sinensis peel ash (CSPA)@Fe3O4 was developed for the synthesis of biodiesel from waste cooking oil (WCO). The core-shell structure of the catalyst enhanced the surface properties and maintained a controlled size and shape of the catalyst, thus improved the catalyst stability to a great extent. The synthesized catalyst was characterized by several analysis techniques. The high amount of potassium and calcium in the Citrus sinensis peel ash (CSPA) catalyst makes it extremely basic and played an important catalytic role in the transesterification of WCO. The CSPA@Fe3O4 catalyzed transesterification afforded a maximum biodiesel yield of 98% under the optimized reaction conditions such as 6:1 methanol/oil molar ratio, 6 wt% catalyst loading, 65 degrees C temperature and 3 h time. The activation energy of the reaction was found to be 34. 41 KJ mol(-1), which indicated that the transesterification of WCO using the present catalyst is chemically controlled reaction. Beneficially, the magnetic iron oxide core endorsed easily recoverable of the catalyst from the reaction mixtures by using an external magnet. Moreover, the catalyst showed high physical stability and reactivity up to the 9 consecutive cycles, demonstrating it as a promising solid base catalyst for sustainable production of biodiesel.

Automated summary

A magnetic nano-sized solid catalyst, derived from bio-waste Citrus sinensis peel ash (CSPA)@Fe3O4, was developed for efficient synthesis of biodiesel from waste cooking oil (WCO) through transesterification. The core-shell structure of the catalyst enhanced surface properties and stability, leading to a high biodiesel yield of 98%. This catalyst showed great potential as a solid base catalyst due to its high stability and recyclability.