Preparation and characterization of animal bone powder impregnated fly ash catalyst for transesterification

Highlights: • Fly ash supported calcined animal bone powder catalyst is prepared using wet impregnation method. • Prepared catalyst was utilized for biodiesel production from mustard oil. • Biodiesel conversion of 90.4% was achieved at CABP loading of 10 mass%. • Prepared catalyst was reused five times without any reduction in activity. -- Abstract: The present work reconnoitres the feasibility of utilizing class F fly ash and calcined animal bone powder (CABP) as raw material for the synthesis of heterogeneous solid base catalyst with varying ratios (CABP of 10, 20, and 30 mass%), that is subsequently used for transesterification of mustard oil. Physicochemical characterization of CABP revealed crystalline behavior, signifying one of the components as hydroxyapatite (HAP); when calcined at 900 °C transforms to β–tricalcium phosphate having a specific surface area of 100 m² g⁻¹. The synthesized catalyst showed improved catalytic activity when compared to the parental species and the optimal value to achieve the highest conversion of 90.4% would be at CABP loading of 10 mass%, 5.5:1 methanol to oil molar ratio, and 10 mass% catalyst concentration for 6 h. The prepared biodiesel had a calorific value of 36.2 MJ kg⁻¹ with ash content < 0.01 mass%. The catalyst could be reused five times with no loss in its activity. Results indicated that calcium enriched waste materials when impregnated in fly ash might be a potential source of catalyst in biodiesel production.