Advanced Adsorbents Based on Engineered Porous Carbon for the Removal of CO۲ and H۲S from Gas Streams

The removal of acid gases such as carbon dioxide (CO۲) and hydrogen sulfide (H۲S) from natural gas, biogas, and refinery streams remains a critical challenge for achieving stringent environmental regulations, improving fuel quality, and ensuring process safety. In recent years, engineered porous carbon adsorbents have emerged as highly promising materials due to their tunable pore architecture, high surface area, chemical stability, and potential for surface functionalization. This review provides a comprehensive and critical analysis of the design strategies, adsorption mechanisms, and performance optimization of advanced porous carbon materials for simultaneous and selective removal of CO۲ and H۲S from gas streams. Particular emphasis is placed on structure-property relationships, including the role of microporosity in enhancing physisorption of CO۲, the influence of mesopores on diffusion kinetics, and the contribution of heteroatom doping (N, O, S) and metal impregnation in promoting chemisorption of H۲S. The review systematically discusses synthesis approaches such as chemical activation, templating methods, biomass-derived carbons, and post-synthetic functionalization, highlighting their impact on adsorption capacity, selectivity, and regenerability. Furthermore, competitive adsorption behavior in multicomponent systems, moisture effects, and cyclic stability are evaluated to provide realistic insights for industrial implementation. Recent advances in hybrid adsorption systems, including metal-oxide-decorated carbons and hierarchical porous structures, demonstrate significant improvements in acid gas removal efficiency and process intensification. The integration of computational modeling, molecular simulations, and data-driven screening is also examined as a pathway toward rational adsorbent design. Overall, engineered porous carbons represent a versatile and scalable platform for next-generation gas purification technologies. Future research directions are proposed, focusing on enhancing adsorption selectivity under realistic conditions, improving long-term stability, and developing sustainable low-cost precursors to enable large-scale deployment in carbon capture and desulfurization processes.

Keywords:

Porous Carbon Adsorbents , Surface Functionalization , Hierarchical Porous Structures , Gas Separation Technology , Biomass-Derived Carbon , Gas Purification