Synthesis, Adsorption and Catalytic Properties of Eggshell-Coconut Pith for Transesterification of Waste Cooking Oil

Abstract

This study aims to develop a sustainable heterogeneous biocatalyst prepared from calcined eggshell waste impregnated with waste coconut piths for producing biodiesel from used cooking oil. Waste eggshells were subjected to thermogravimetric analysis for calcinations at suitable temperature under inert atmosphere. It was subjected to impregnation of coconut pith by physical and chemical adsorption. The prepared eggshell-coconut pith catalyst was optimized at different parameters like temperature, mass ratio of coconut pith, eggshell and variant concentration of the solvent used for socking of coconut pith and eggshell. The adsorption of coconut pith on the eggshell surface were characterized by BET analysis and SEM analysis, the size of atom of eggshell was increased after impregnation of coconut pith by 100 μm. The adsorption of coconut pith on eggshell was validated by Langmuir and Freundlich adsorption models and order of impregnation reaction was verified by pseudo-first and pseudo-second order models. The effect of process parameters like amount of catalyst loading, oil: alcohol ratio, time, speed of iteration, pH of the solvent and temperature, which enhanced the yield of biodiesel to ~ 87%.