Optimization to prepare porous carbon from mustard husk using response surface methodology adopted with central composite design

Abstract

Mustard husk was used as a non-conventional precursor to derive porous carbon by chemical activation using KOH. The effects of three crucial preparation variables - activation temperature, impregnation ratio and activation time on methylene blue dye uptake and porous carbon yield was studied using central composite design. The selected process variables were optimized with an intention to maximize both methylene blue uptake and yield. Activation temperature showed prominent effect on both the responses. The effect of activation time was relatively less significant on methylene blue uptake. At an optimized condition of activation temperature 738.8 °C, impregnation ratio 2.0 and activation time 60.0 min, the model predicted and experimental values for both the responses were highly comparable. The carbon derived at optimized conditions was characterized by several analytical techniques and reusability up to five adsorption-desorption cycles was tested. The results indicated highly porous structure comparable to commercial grade activated carbon.