Synthesis of hierarchical nanoporous HY zeolites from activated kaolin, a central composite design optimization study

In this article, we investigated the optimum formulation towards synthesis of hierarchical nanoporous HY zeolites from acid activate kaolin. A central composite design (CCD) helped to examine the influence of aging (X-1), crystallization (X-2) and NaOH solution to kaolin ratio (X-3) on crystallinity (C%), specific surface area (SSA) and hierarchical factor (HF). From the analysis of variance (ANOVA), we deduced that all the process variables show statistical significance towards obtaining high C% and SSA while only X3 is statistically significant for optimal HF. The effectiveness of models was further evaluated using margin of error and tolerance interval. The Optimum formulation for this hierarchical nanoporous HY zeolite was 43.60, 6423 and 6.97 for X-1, X-2, and X-3, respectively. The developed models show that X-3 is the most statistically significant variable because it has the highest coefficient and the lowest p-value in the entire model. These results give instrumental insight into the synthesis of hierarchical nonporous HY zeolite. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.