초록 |
The high dielectric strength of SF6 makes the gas useful in gas-insulated switchgear, where SF6 is typically mixed with relatively cheap N2. However, SF6 has been identified as one of the main greenhouse gases due to its high global warming potential (GWP: 22,800 - 23,900). We proposed multi-scale screening, which employs both molecular and process-level methods, to identify high-performing MOFs for energy efficient separation of SF6 and N2 mixture. Grand canonical Monte Carlo (GCMC) simulations were combined with ideal adsorption process simulation to computationally screen 2,890 metal-organic frameworks (MOFs). 78 MOFs selected for the VSA conditions were able to achieve the 90 % target purity level of SF6, but 62 top-performing MOFs selected for the PSA condition could not reach the purity level with a single train PSA configuration. Cascade PSA configuration was proposed and adopted to improve the purity level. Finally, the process-level performance of top-performing MOFs (HKST-1, UiO-67) was evaluated on the basis of the experimental isotherms obtained from the literature and compared with the other materials reported in the literature (MIL-100(Fe), UiO-66, and zeolite 13X). |