Optimizing Zeolite 13X Synthesis from Kaolin Clay for Higher CO ₂ Adsorption: A Statistical Approach

Abstract Zeolite 13X is a promising material for CO 2 capture due to its high adsorption kinetics and capacity. However, limited studies systematically evaluate the effect of synthesis parameters on performance. This study uses a design of experiments (DoE) approach to examine the influence of silica‐to‐alumina ratio, aging time, crystallization time, and temperature on CO 2 uptake. Kaolin, a low‐cost natural clay, served as the raw material. Synthesis conditions were selected based on extreme values reported in literature to cover a broad range. The resulting zeolite 13X showed up to three times higher CO 2 adsorption capacity than previously reported for kaolin‐derived variants. Characterization via XRD, CO 2 /N 2 isotherms, and SEM confirmed structural integrity and performance. Among variables, crystallization temperature had the strongest positive effect, with others influencing within specific ranges. Statistical modeling identified the linear model as significant (R 2 = 0.76, p = 1.43 × 10 −5 ), while the cubic model achieved the best fit (p = 0.014). Model selection was further refined using additional statistical metrics. Optimal conditions yielded a CO 2 adsorption capacity of 4.7 ± 0.3 mmol/g at atmospheric pressure and 30 °C temperature. These results emphasize the need for careful synthesis optimization to enhance the carbon capture performance of zeolite 13X.