Microwave irradiated Palm shell-polyetheretherketone porous carbons as CO₂ sorbents: Optimization using response surface methodology (RSM)

Palm shell being one of the abundant biomass in Malaysia, was used together with polyetheretherketone (PEEK) as precursors for the preparation of porous carbons via microwave induced potassium carbonate chemical activation. Design expert software version 7.1.6 using central composite design coupled with surface response methodology was used in predicting and optimization of the CO₂ adsorption of the porous carbons. Effect of three independent variables (i.e. microwave power, irradiation time and amount of PEEK) on the sorbent performance for CO₂ adsorption was investigated. A quadratic model was developed to calculate the optimum preparation conditions of activated carbon, which relate the factors to the response (CO₂ adsorption). The influence of process parameters on the properties of porous carbon was investigated using analysis of variance (ANOVA) to identify the significant parameters. Microwave power was found to be the most significant factor influencing the porous carbon for CO₂ adsorption. The porous carbons (PCs) preparation conditions were optimized by maximizing the CO₂ adsorption capacity. The predicted CO₂ adsorption capacities from the models agreed satisfactorily with the experimental values. The optimum carbon was obtained at microwave power of 500 W; irradiation time 6.55 min; and amount of PEEK 26.03 %. Therefore, the Microwave-irradiated palm-PEEK was found to be a suitable adsorbent for uptake of CO₂.