A theoretical study on the separation of CO2/CH4 through MFI zeolite

Molecular Insights into Adsorption and Diffusion Properties of CO2/CH4 in Cation-Exchanged ZSM-5 Zeolites

“…At approximately 300 K, the simulation result of D s is 0.52 × 10 –9 m 2 /s, which is close to the results from other work (0.3 × 10 –9 m 2 /s) . Also, this is much lower than that value in silicalite-1 (3 × 10 –9 m 2 /s) …”

“…The electrostatic potential was calculated using the Ewald summation method, with an accuracy set to 10 –5 kcal/mol. Also, the van der Waals interaction was calculated by an atom-based method, with a potential cutoff interval of 18.5 Å. , Additionally, the equilibrium steps were set to 10 6 , followed by 10 7 production steps . Next, the adsorption isotherms of the pure CO 2 and CH 4 substances or mixtures in the three M-ZSM-5 models were analyzed.…”

“…The molecular dynamics simulation was conducted under the NVT ensemble, where the number of particles, volume, and temperature were fixed. , The temperature was controlled by the Nosé method . Similarly, the PCFF force field was selected to describe the motion of guest molecules. ,, The electrostatic potential was calculated using the Ewald summation method, with an accuracy of 10 –4 kcal/mol. Also, the van der Waals interaction was calculated by an atom-based method, with a cutoff radius of 15.5 Å .…”

“…At present, the most promising and widely studied adsorption or separation materials include zeolites, carbon-based materials, and metal–organic frameworks (MOFs). − Among them, zeolites have garnered widespread attention due to their high separation performance, excellent stability, and low cost. , ZSM-5 (MFI) is a medium-pore zeolite, which is highly representative and worth studying. − Previously, we had already studied CO 2 /CH 4 separation based on it . Meanwhile, this article is more concerned about the cation-exchanged ZSM-5 (M-ZSM-5) zeolites obtained after modification.…”

“…Also, molecular simulations, including Monte Carlo (MC) and molecular dynamics (MD) methods, are powerful tools for theoretical calculations. − It can not only explain some phenomena in experiments but also further guide the optimization and improvement of processes. In our previous work, we have analyzed the adsorption and diffusion properties of CO 2 and CH 4 in silicalite-1 (structure-type MFI) under different temperatures and pressures. The adsorption isotherms, isosteric heats, and self-diffusion coefficients of pure or mixed components were obtained.…”