On the other hand, to succeed in large-scale industrial application, gas separation membranes should satisfy not only high “separation ability” i.e., selectivity towards CO 2 (e.g., >40 in post-combustion CO 2/N 2 separation), but also significantly higher “separation speed” i.e., permeance numbers (>1000 GPU). Membrane systems are viewed as competitive to conventional CO 2 capture systems due to versatility, relative simplicity, potentially lower energy consumption, and lower capital cost as well as smaller environmental footprint. In particular, separation from ubiquitous flue-gas originating from heat-power plants is needed to achieve cost-efficient CO 2 capture and prevent global warming. Membranes are considered a potentially effective tool for separation of carbon dioxide (CO 2) from gas mixtures. Material properties changed at low thicknesses-surface treatments and influence of porous support are discussed as possible reasons for observed deviations. Surprisingly, a significant decrease from model predictions was observed when the thickness of the polydimethylsiloxane (PDMS) (gutter layer) became relatively small (below 2 µm thickness). Model prediction for permeance/selectivity corresponded perfectly with experimental data for the thicker membranes.
Pdms 11.6 for free series#
CO 2 and N 2 transport through membranes with different thicknesses of two layers has been investigated both experimentally and with the utilization of resistance in series models. In this work, we have investigated the Pebax ®-MH1657/PDMS double layer membrane as a selective/gutter layer combination that has the potential to achieve sufficient CO 2/N 2 selectivity and permeance for efficient CO 2 and N 2 separation. Moreover, the performance of defect-free layers with known gas permeability can be effectively described using the classical resistance in series models to predict both permeance and selectivity of the composite membrane. The effect of thickness in multilayer thin-film composite membranes on gas permeation has received little attention to date, and the gas permeances of the organic polymer membranes are believed to increase by membrane thinning.
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