Development of reusable composite eggshell-moringa leaf catalyst for biodiesel production

A reusable heterogeneous composite catalyst was prepared from mixtures of poultry eggshells and moringa leaves for the production of biodiesel (BD). The raw materials were mixed using a micro ball mill for 4 h and then calcinated at a temperature of 800 ? for 3 h. The developed catalyst was used to promote the transesterification reaction of soybean oil and methanol to produce BD. The X-ray diffraction results revealed the presence of predominantly CaO after activation at 800 ?. Meanwhile, the individual raw materials showed the presence of alkaline metal oxides such as CaO for the eggshell residue and Ca(OH)(2), MgO and CaO for the moringa leaves. The catalyst has a surface area of 5.3 m(2) g(-1) and appreciably high basicity of 4.95 mmol/g, which tailored the transesterification reaction. Under the best reaction conditions of 2 wt% catalyst loading, 12:1 methanol to soybean oil molar ratio and a reaction temperature of 65 ?, 94.3% of fatty acid methyl ester (FAME) yield was achieved in 78 min. The heterogeneous catalyst can be reused for 9 consecutive cycles with a slight decrease in activity due to leaching. The biodiesel produced meets the international quality standards of ASTM D-6751 and EN 14214. In conclusion, a combination of agro-waste sources could promote stability in the reaction medium and effectively catalyze the BD production.

Automated summary

A reusable heterogeneous composite catalyst was prepared from a mixture of poultry eggshells and moringa leaves, and effectively catalyzed the production of biodiesel. The catalyst has high surface area and basicity, which tailored the transesterification reaction. The biodiesel produced meets international quality standards and the catalyst can be reused for multiple cycles.