Optimization of green and environmentally-benign synthesis of isoamyl acetate in the presence of ball-milled seashells by response surface methodology

Abstract

Ball-Milled seashells, as a nano-biocomposite catalyst and natural source of CaCO3 in its aragonite microcrystalline form and fixed CO2, was optimized for the synthesis of isoamyl acetate by response surface methodology (RSM) with a five-level three-factor rotatable circumscribed central composite design (RCCCD). The seashells nano-biocomposite was proved to be an excellent heterogeneous catalyst for the green and environmentally-benign synthesis of isoamyl acetate from acetic acid and isoamyl alcohol under solvent-free conditions. High yield of 91% was obtained under the following optimal conditions: molar ratio of alcohol: acetic acid (1:3.7), catalyst loading (15.7 mg), the reaction temperature (98°C), and the reaction time (219 min). The outstanding advantages of this protocol are the use of a naturally occurring and easily prepared nano-biocomposite material without any modifications with hazardous reagents, lower catalyst loading and required temperature, avoiding the use of corrosive Bronsted acids as well as toxic azeotropic solvents or water adsorbents, and simplicity of the procedure.