Probing Methane Adsorption in MIL Metal-Organic Frameworks using Molecular Dynamics Simulations

In this study, we investigated the adsorption properties of three metal-organic frameworks (MOFs): MIL-101(Cr), MIL-100(Fe), and MIL-100(Al), for high-pressure methane storage in Adsorbed Natural Gas (ANG) applications. Utilizing the Materials Studio software and Monte Carlo simulations, we conducted molecular dynamics simulations under a constant pressure of 35 atm and a temperature of 300 K. The results revealed distinct methane adsorption capacities for each MOF, with values of 0.008 g, 0.089 g, and 0.035 g of methane per gram of adsorbent for MIL-101(Cr), MIL-100(Fe), and MIL-100(Al), respectively. To validate our findings, we compared the calculated adsorption capacity of MIL-101(Cr) with experimental data, resulting in a close match with the reported value of 0.036 g of methane per gram of absorbent. The simulations also unveiled insights into the adsorption patterns, demonstrating that methane molecules selectively interacted with different regions of the frameworks based on their orientation. Our study suggests that MOFs hold promise as suitable adsorbents for natural gas storage in ANG technologies. Among the three studied MOFs, MIL-100(Al) emerged as the most efficient option, presenting potential for future industrial-scale implementation, subject to economic and production considerations. These results further emphasize the significance of nanomaterials, particularly MOFs, in advancing ANG development and highlight the importance of validation with experimental data to ensure accuracy and reliability.