Preparation of a CaO Nanocatalyst and Its Application for Biodiesel Production Using <i>Butea monosperma</i> Oil: An Optimization Study

Abstract

Abstract CaO nanoparticles (NP) were synthesized through solution combustion using crude glycerin (biodiesel by‐product) as the combustion fuel. The synthesized CaO NP were characterized using Fourier transform infrared spectrometer (FTIR), X‐ray diffractometer (XRD), temperature programmed desorption of carbon dioxide (CO 2 ‐TPD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The CaO NP were successfully used as a catalyst for biodiesel synthesis. Response surface methodology was used to determine the optimal conditions for biodiesel production from Butea monosperma oil (BMO) using central composite design. A total of 20 experiments were designed and conducted to study the effects of the methanol to BMO molar ratio, reaction time, and catalyst loading conditions on the biodiesel yield. A yield of 96.2% of Butea monosperma methyl ester (BMME or biodiesel) was obtained under optimum conditions, namely a molar ratio (methanol to BMO) of 9:1, a reaction time of 70 min, a catalyst loading of 1.60 wt%, a constant temperature of 65 °C, and an agitation speed of 600 rpm. The fatty‐acid composition of BMO was characterized through gas chromatography. Finally, BMME was characterized using FTIR, 1 H NMR, and 13 C NMR, and the fuel properties of BMME were determined using the test methods of the American Society for Testing and Materials.