Transforming Natural Resources into Advanced Solutions: The Contribution of Clay-Based Adsorbents to Carbon Dioxide (CO₂) Adsorption

Carbon capture and storage (CCS) is an advanced environmental technology for mitigating CO₂ emissions and addressing climate change. Among the various approaches, adsorption has emerged as a promising method for CO₂ capture due to its effectiveness and practicality. This review explores the potential of clay minerals as adsorbents for CO₂ capture, providing an in-depth analysis of their inherent properties and the mechanisms involved in adsorption process. The review begins with an introduction to CCS and the concept of adsorption, followed by a detailed examination of various clay minerals, including sepiolite, montmorillonite, bentonite, kaolinite, saponite, halloysite, and illite. Each mineral’s suitability for CO₂ adsorption is assessed, highlighting the specific properties that contribute to their performance. The mechanisms of CO₂ adsorption including physisorption, chemisorption, ion exchange, pore diffusion, intraparticle diffusion, surface complexation, and competitive adsorption are thoroughly discussed. The review also covers the modification of clay minerals through physical and chemical treatments, amine functionalization, and composite formation to enhance their CO₂ adsorption capacity. Additionally, regeneration methods such as temperature-swing adsorption (TSA), pressure-swing adsorption (PSA), and purging are discussed, along with CO₂ recovery and storage techniques for improving energy efficiency. The review concludes with an overview of characterization methods for clay-based adsorbents and potential applications, while addressing the challenges and future trends in the field. This work emphasizes the promising role of clay-based adsorbents in advancing CCS technology.