Statistical optimization of the Zinc chloride activated biomass using Box-Behnken design

Abstract

The preparation of activated carbon from an economically sustainable precursor Limonia acidissima shell (an agricultural waste) by chemical activation method has been explored in the present study. This investigation emphasizes the application of a statistical tool, Response surface methodology (RSM) coupled with Box-Behnken design (BBD) to optimize the experimental conditions for the preparation of activated carbon from lignocellulosic wastes activated with ZnCl₂. The chemical activation is conducted at a different combination of impregnation ratios (IR), activation time and carbonization temperatures as suggested by the Design Expert software. The influences of these parameters on the responses i.e. iodine no. and yield of activated carbon has been investigated. Simultaneous optimization is performed using desirability approach. The desirability value reported for AC-ZnCl₂ is 0.653. The carbon yield and iodine adsorption value approached 49.67% and 928.58 mg/g under the optimal conditions of impregnation ratio (1), activation time(57.09 min),and carbonization temperature (436.52°C). Important physicochemical properties of the optimized activated carbon is further confirmed by FTIR analysis, TEM analysis etc.