Computational Screening of MOF-Based Mixed Matrix Membranes for CO2/N2Separations

Zeynep Sumer,Seda Keskin

doi:10.1155/2016/6482628

Abstract

Atomically detailed simulations were used to examine CO2/N2separation potential of metal organic framework- (MOF-) based mixed matrix membranes (MMMs) in this study. Gas permeability and selectivity of 700 new MMMs composed of 70 different MOFs and 10 different polymers were calculated for CO2/N2separation. This is the largest number of MOF-based MMMs for which computational screening is done to date. Selecting the appropriate MOFs as filler particles in polymers resulted in MMMs that have higher CO2/N2selectivities and higher CO2permeabilities compared to pure polymer membranes. We showed that, for polymers that have low CO2permeabilities but high CO2selectivities, the identity of the MOF used as filler is not important. All MOFs enhanced the CO2permeabilities of this type of polymers without changing their selectivities. Several MOF-based MMMs were identified to exceed the upper bound established for polymers. The methods we introduced in this study will create many opportunities to select the MOF/polymer combinations with useful properties for CO2separation applications.

Highlights

Emission of CO2 has become a serious concern due to increased global warming
80 zeolitic imidazolate frameworks (ZIFs)-based and 200 PCN-based matrix membranes (MMMs) were examined using molecular simulations and our results showed that a large number of ZIF- and PCN-filled MMMs have higher CO2 permeability and higher CO2/N2 selectivity than the pure polymers
Our results showed that atomically detailed simulations can be used to select the appropriate MOF filler particles for polymers that will yield MMMs with extraordinary CO2/N2 separation properties

Summary

Introduction

Emission of CO2 has become a serious concern due to increased global warming. Capture of CO2 from power plant flue gas, a mixture composed mainly of water-saturated N2 with smaller amounts of O2 and other species, is highly important. We recently developed a computational approach that combines atomically detailed simulations with continuum modeling to assess gas separation performances of MOF-based MMMs [26] The accuracy of this approach was validated by comparing the predictions of our method with the available experimental gas permeability measurements of fabricated MOF-based MMMs such as IRMOF-1/Matrimid, CuBTC/PSf, and CuBTC/PDMS [27]. This method was used to estimate the potential of new MOF-based MMMs in CO2/CH4 and CH4/H2 separations [27, 28]. Our results showed that atomically detailed simulations can be used to select the appropriate MOF filler particles for polymers that will yield MMMs with extraordinary CO2/N2 separation properties

Computational Details

Results and Discussion

Conclusion