The impact of water vapor on CO2 separation performance of mixed matrix membranes

Abstract

a b s t r a c tA series of mixed matrix membranes (MMMs) using nanoparticles involving carbons, porous organic polymers and metal organic frameworks (MOFs) were prepared to investigate the impact of water vapor on CO 2 separation performance. The water uptake of MMMs using hydrophilic MOFs increased relative to more hydrophobic particles such as the porous organic polymers and carbons and this trend was reflected in the water vapor permeability, which varied by a factor of three between the hydrophobic and hydrophilic MMMs. These changes in water vapor permeability were strongly correlated with the water solubility, indicating that it is this solubility that is the controlling parameter. The calculated water diffusivity was consistent with previously published results. The gas permeability of MMMs in the presence of water vapor was also strongly affected by the nanoparticle hydrophobicity, with membranes composed of hydrophobic fillers out-performing hydrophilic fillers of comparable porosity. However in general, the differences in performance between MMMs and the pure polymer narrowed in the presence of water vapor.

Can the addition of carbon nanoparticles to a polyimide membrane reduce plasticization?

“…Conversely, there is little, if any, change in the gas selectivities for any gas pair. This type of behavior has been reported previously for mixed matrix systems [14,49,50] and in our own earlier reports [29,30] and reflects the increasing FFV in the membranes provided by the nanoparticles (Figure 1). permeability of the mixed matrix membranes.…”

“…The FFV value calculated for pure Matrimid using this approach was 0.167. The FFV of the carbon was determined in our previous work from the pore volume and the particle density as 0.540 [29,30]. The FFV of the ideal MMM is then expressed as Equation 5:…”

“…[28] In our more recent work, we have also shown that carbon nanoparticles can be similarly effective in improving the gas separation performance in mixed matrix systems. [29,30] Further, these particles are likely to be available at more moderate cost than additives such as metal organic frameworks (MOFs). In this work, we expand on these results to provide a more detailed analysis of the effectiveness of carbon-based mixed matrix systems across a range of operating pressures and water vapor humidities.…”

Influence of Filler Pore Structure and Polymer on the Performance of MOF‐Based Mixed‐Matrix Membranes for CO2 Capture

“…However, in spite of an explosion in the number of publica-tions dealingw ith MOF-based MMMs,c lear structure-property relationships fort hese composites and the influence of MOF structureo np ore dimensionality anda ccessibility have not yet been established. [41,42] More comparative studies on diverse MOF fillers and polymers are required to determine the optimal combinations and ruling variables to facilitatethe development of such structure-performancec orrelations.…”

Study of the Effect of Inorganic Particles on the Gas Transport Properties of Glassy Polyimides for Selective CO₂ and H₂O Separation

“…Polyimides were selected due to their outstanding gas transport properties for several gas pairs as CO2/CH4 or O2/N2 and, in case of studied polymers, excellent film forming properties. The six inorganic materials used as nano-sized particles were selected taking into account the expected good affinity for gas molecules as CO2 and water vapour [23].…”