Multi-objective optimization of the preparation parameters of the powdered activated coke for SO2 adsorption using response surface methodology

Abstract

Production cost can be reduced in preparation of powdered activated coke (PAC) by achieving higher SO2 adsorption capacity and lower burn-off. In this study, for the rapid preparation of PAC from pulverized coal, response surface methodology (RSM) based on central composite design (CCD) was used to develop the second order quadratic models of SO2 adsorption capacity and burn-off. Analysis of variance (ANOVA) was used to determine the effective parameters of the two models, and to explain the accuracy and fitness of them. In addition, the 3D response surface plots illustrated the influencing rules of the variables and their interactions. Further, multi-objective optimization was performed to maximize SO2 adsorption capacity and minimize burn-off using the desirability function. Optimal process parameters obtained were: reaction temperature, 923.97 ℃; oxygen concentration, 5.89 % and vapor concentration, 20.04 %; and the corresponding prediction results were: SO2 adsorption capacity, 110.31 mg/g; burn-off, 47.45 %. Confirmation experiment at the optimal condition was carried out, and the experimental results were consistent with the model prediction results, further verifying the accuracy and fitness of the models. The optimization results would provide guidance for the design and operation adjustment of large-scale industrial applications in the future.