Pine cone-based activated carbon via dual physical activation for efficient carbon dioxide capture: Experimental and molecular simulation studies

Bio-based activated carbon is a promising adsorbent material for carbon capture due to its renewability, high adsorption capacity, and low cost. This study investigates pine cone-derived activated carbon prepared through an innovative dual physical activation process using CO2 and steam, focusing on the effects of activation parameters on structural properties and CO2 capture performance. The optimized material demonstrates a specific surface area of 1321.6 m2/g, a microporous volume of 0.354 cm3/g, and an excellent CO2 adsorption capacity of 3.2 mmol/g at 298.15 K and 1 bar. Structural analysis underscores the critical role of microporous volume in enhancing CO2 adsorption. A virtual porous carbon model is developed by combining experimental characterization with molecular simulations. The Grand Canonical Monte Carlo results indicate good CO2 selectivity under simulated flue gas conditions. The Density Functional Theory calculations reveal that pentagonal defects in the carbon skeleton act as preferential adsorption sites, with CO2 exhibiting stronger interaction energy (−21.83 kJ/mol) compared to N2 (−15.85 kJ/mol) and O2 (−15.39 kJ/mol). This study integrates experimental and molecular modeling approaches to develop efficient CO2 adsorbents, providing valuable insights into adsorption mechanisms and guiding the design of sustainable carbon capture materials for practical applications.