Application of Response Surface Methodology for the Optimization of Drying Parameters of ZSM-5 Extruded Catalysts

A fundamental step in the fabrication of industrial catalysts is to conduct mechanical properties assessment. In this paper, the mathematical models were adequately developed to optimize the mechanical properties of ZSM-5 extruded catalysts using response surface methodology. And central composite orthogonal design with three parameters viz. drying temperature, drying time, and moisture content was utilized to investigate the effects of drying parameters on the mechanical strength and Weibull modulus. Statistics showed that the responses varied regularly with the development of experiments. And a material with optimal mechanical properties would possess both higher mechanical strength and Weibull modulus. Furthermore, it was found that drying process significantly impacts the morphology of the extruded catalysts, rather than the pore structure through the analysis of scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET). Thus, we concluded that the reduction in surface crack size is the main reason of the improvement of mechanical properties.