Production and optimization of activated carbon from waste orange peels using microwave pyrolysis

Abstract

Global production of oranges is massive due to the high consumer demands in orange fruit and its by-products. Over 40 % of the orange fruit is disposed as fruit waste after industrial processing, and this could decrease landfill capacity and create environmental pollution problems. Recent researches have discovered the potential of converting waste orange peels (WOP) into orange peel activated carbon (OPAC). Hence, the aim of this research is to optimize the production of activated carbon from WOP using response surface methodology. WOP will be carbonized at 700 W for 20 minutes using microwave pyrolysis. Next, the orange peel char (OPC) produced will be chemically activated using sodium hydroxide and potassium hydroxide via microwave pyrolysis, under different conditions. The chemical activation of OPC will be conducted with optimization of three parameters: microwave power (W) (x1), microwave irradiation time (min) (x2) and impregnation ratio between OPC and chemical (x3). The activated carbon produced from optimized operating parameter set has a high AC yield of97 %wt and an adsorption efficiency of 28.5 mg/g on removal of Malachite Green (MG) in water. All in all, the research is able to recycle WOP into useful material (activated carbon) for other applications.