Downstream permeation curve

In the experiments we were able to measure the flux and then, after integration with respect to time, we obtain a downstream permeation curve (shown in Figure 9.7) where the typical plot of versus time is presented. 

Figure 9.7 Downstream absorption permeation curve - a schematic view. Reprinted with permission from Journal of Membrane Science, On the air enrichment by polymer magnetic membranes by A. Rybak, Z. j. Crzywna and W. Kaszuwara, 336, 1-2, 79-85, Copyright (2009) Elsevier Ltd...

Figure 9.10 Downstream absorption permeation curves for various polymer and magnetic membranes. Points marked as squares, magnetic membrane with B = 1.25mT stars, magnetic membrane with B = 0.79mT triangles, magnetic membrane with B = O.SOmT asterisk, plane EC membrane...

Although extensive data for mixed-gas permeation in the plasticization regime are not available, good pure-gas values are available and illustrate some important points. The permeability of CO2 in various substituted polycarbonates shown in Figure 28 (111) increases with pressure above a certain characteristic value for each of the polymers. The shapes of the permeability curves are like the curve shown schematically in Figure 21. Plasticization occurs despite the fact that the downstream pressure is maintained at a vacuum of less than 1330 Pa (10 mm Hg). To determine when true transport plasticization occurs, the local diffusion coefficient Dap(Ca), which measures the ability of a penetrant to move through the membrane at a point where the local concentration of penetrant is equal to Ca, must be considered. The sorption isotherms for CO2 in the various materials are shown in Figure 29 (111), and application of the standard... 

Figure 12.17 Effect of feed inlet temperature on MD flux obtained using PP capillary (Accurel S6/2 MD020CP2N, Table 12.1) with feed flow velocity 0.8 m/s. In DCMD (0.8 m/s permeate flow velocity, 20°C permeate inlet temperature) in SGMD (11.3 m/s humid air velocity, 20°C air inlet temperature) in VMD (3500 Pa downstream pressure). The solid lines are theoretical prediction curves. (Adapted from Khayet et al., 2003c.)...

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