4 research outputs found
Database for CO2 separation performances of MOFs based on computational materials screening
Metal-organic frameworks (MOFs) are potential adsorbents for CO2 capture. Because thousands of MOFs exist, computational studies become very useful in identifying the top performing materials for target applications in a time-effective manner. In this study, molecular simulations were performed to screen the MOF database to identify the best materials for CO2 separation from flue gas (CO2/N-2) and landfill gas (CO2/CH4) under realistic operating conditions. We validated the accuracy of our computational approach by comparing the simulation results for the CO2 uptakes, CO2/N-2 and CO2/CH4 selectivities of various types of MOFs with the available experimental data. Binary CO2/N-2 and CO2/CH4 mixture adsorption data were then calculated for the entire MOF database. These data were then used to predict selectivity, working capacity, regenerability, and separation potential of MOFs. The top performing MOF adsorbents that can separate CO2/N-2 and CO2/CH4 with high performance were identified. Molecular simulations for the adsorption of a ternary CO2/N-2/CH4 mixture were performed for these top materials to provide a more realistic performance assessment of MOF adsorbents. The structure-performance analysis showed that MOFs with Delta Q(st)(0) > 30 kJ/mol, 3.8 angstrom 1 g/cm(3) are the best candidates for selective separation of CO2 from flue gas and landfill gas. This information will be very useful to design novel MOFs exhibiting high CO2 separation potentials. Finally, an online, freely accessible database https://cosmoserc.ku.edu.tr was established, for the first time in the literature, which reports all of the computed adsorbent metrics of 3816 MOFs for CO2/N-2, CO2/CH4, and CO2/N-2/CH4 separations in addition to various structural properties of MOFs.European Research Counci
Computational Screening of Metal–Organic Frameworks for Membrane-Based CO<sub>2</sub>/N<sub>2</sub>/H<sub>2</sub>O Separations: Best Materials for Flue Gas Separation
It
has become a significant challenge to select the best metal–organic
frameworks (MOFs) for membrane-based gas separations because the number
of synthesized MOFs is growing exceptionally fast. In this work, we
used high-throughput computational screening to identify the top MOF
membranes for flue gas separation. Grand canonical Monte Carlo and
molecular dynamics simulations were performed to assess adsorption
and diffusion properties of CO<sub>2</sub> and N<sub>2</sub> in 3806
different MOFs. Using these data, selectivities and permeabilities
of MOF membranes were predicted and compared with those of conventional
membranes, polymers, and zeolites. The best performing MOF membranes
offering CO<sub>2</sub>/N<sub>2</sub> selectivity > 350 and CO<sub>2</sub> permeability > 10<sup>6</sup> Barrer were identified.
Ternary
CO<sub>2</sub>/N<sub>2</sub>/H<sub>2</sub>O mixture simulations were
then performed for the top MOFs to unlock their potential under industrial
operating conditions, and results showed that the presence of water
decreases CO<sub>2</sub>/N<sub>2</sub> selectivity and CO<sub>2</sub> permeability of some MOF membranes. As a result of this stepwise
screening procedure, the number of promising MOF membranes to be investigated
for flue gas separation in future experimental studies was narrowed
down from thousands to tens. We finally examined the structure–performance
relations of MOFs to understand which properties lead to the greatest
promise for flue gas separation and concluded that lanthanide-based
MOFs with narrow pore openings (<4.5 Ă…), low porosities (<0.75),
and low surface areas (<1000 m<sup>2</sup>/g) are the best materials
for membrane-based CO<sub>2</sub>/N<sub>2</sub> separations