Transesterification of waste cooking oil for biodiesel production catalyzed by Zn substituted waste egg shell derived CaO nanocatalyst

摘要

This research paper deals with the synthesis of efficient and low cost heterogeneous catalyst from waste egg shells by wet impregnation method. A series of Zn doped CaO (0.5-2 wt% Zn2+ concentration in CaO) nano catalysts were prepared and employed in the transesterification of waste cooking oil. Synthesized catalysts were characterized by powder X-ray Diffraction (XRD), Fourier Transform-Infrared (FTIR), Scanning Electron Microscopy (SEM), Energy dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) analysis. Various reaction parameters such as Zn doping, catalyst loading, methanol: oil molar ratio and reaction time were optimized following Response Surface Methodology (RSM) based on Box-Behnken design (BBD). Maximum biodiesel conversion of 96.74% was recorded under the reaction conditions of 20:1 methanol to oil molar ratio, 5 wt% catalyst loading, 65 degrees C reaction temperature and 4 h of reaction time. The confirmation for biodiesel synthesis was performed using Proton Nuclear Magnetic Resonance (H-1 NMR) and Carbon Nuclear Magnetic Resonance (C-13 NMR) techniques. These results suggest that Zn doped CaO nanocatalyst is a promising catalyst for biodiesel production.