CO2 permeation

The permeability of a polymer to a penetrant depends on the multiplicative contribution of a solubility and a mobility term. These two factors may be functions of local penetrant concentration in the general case as indicated by the dual mode model. Robeson (31) has presented data for CO2 permeation in... 

Transfer mechanisms involved in SC CO2 permeation through such porous membranes can be convection (Poiseuille law), diffusion (Knudsen flow), and surface membrane interaction by adsorption, capillary condensation, etc. [11]. Mechanisms have been specifically investigated for nanofiltration and zeolite membranes. With a nanofilter presenting a pore diameter of about 1 nm, Sarrade [11] mentioned a Poiseuille flow associated with an irreversible CO2 adsorption on the micropore wall. Transfer... 

T. Eukuda, T. Maid, K. Mae, Design of a plate-type catalytic microreactor with CO2 permeation membrane for water-gas shift reaction, Chem. Eng. Technol. 35 (2012) 1205-1213. 

FIGU RE 5.5 CO2 permeate purity versus recovery index for pressure ratio of (a) 10 and (b) 50 at different COj/N ideal selectivity from 30 to 300. (Reprinted from J. Membr. Sci., 359, Brunetti, A., Scura, R, Barbieri, G., and Drioli, E., Membrane technologies for COj separation, 115-125, Copyright (2010), with permission from Elsevier.)... 

CO2 Permeation with Pebax -based Membranes for Global Warming Reduction... 

Another type of membrane with high CO2 separation performances is the facilitated transport membrane. Membranes of this type are those in which an amine-based liquid supported by a solid membrane promotes a selective CO2 permeation. They exhibit generally a remarkably high selectivity and also high permeability at low CO2 pressure in the feed gas. Unfortunately, they suffer from very poor stability. For the separation of CO2, fixed carrier membranes were found to have high permselectivity without the drawback of poor stability, but with much lower permeability [13-15]. However, all membranes with amine-based carriers suffer from a strong reduction in performance with the reduction in the relative humidity in the gas mixtures, because the presence of water in the... 

CO2 Permeation with Peba> -based Membranes for Ciobal Warming Reduction 265... 

However, the grafted layer is apparently extremely thin, since no changes were detected in DSC thermograms. The CO2 permeation test indicated that the plasma-modified membrane exhibited a greatly enhanced permeability (144Barrer at 25 °C). 

The flux of methanol through the membrane is usually calculated by measuring the amount of CO2 in the cathodic exhaust (Dohle et al., 2002 Jiang and Chu, 2004). This method, however, is not reliable since CO2 permeates through the membrane from the anode to the cathode side (Dohle et al., 2002). Equation (4.231) provides a simple means for evaluating of the overall crossover current in DMFC by measuring oxygen and/or methanol concentration at the outlet, one can calculate Jcross with (4.231). 

Figure 1. CO2 permeation rates through an SLM. Carrier Aqueous DBA at 1.94 mol.dm. Key O - Experimental Data, Guha et at M-Guha model x - Teramoto model ...

Meldon, J. Paboojian, A. Rajangam, G. 1986, Selective CO2 Permeation in Immobilized Liquid Membranes. AIChE Symp. Series. 248. 

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