Process optimization of K2C2O4-activated carbon from kenaf core using Box–Behnken design

•Kenaf core-based activated carbons were produced by K2C2O4 activation.•The process conditions were optimized by Box–Behnken design.•K2C2O4-based chemical activation is a benign yet very effective activation method.

Potassium oxalate was evaluated as a new activating agent for preparation of kenaf core-based activated carbons. The preparation conditions were optimized through Box–Behnken design (BBD) to maximize I2 and methylene blue (MB) adsorption values. Two quadratic models were developed to correlate the preparation variables namely activation temperature, impregnation ratio and activation time for both responses. The activated carbon produced at the optimum combination of process parameters showed 1161 mg/g and 330 mg/g of I2 and MB uptakes, which were in excellent agreement with the predicted values from the models. Porosity parameters and scanning electron microscopy were used to investigate the obtained optimal sample. The results reveal that K2C2O4 could be recommended as a promising effective activating agent for producing activated carbons from kenaf core with high surface area and potentially desirable dye removal capacity.