Gas-transport in porous media

Gas-diffusion electrode metal-air cells gas-transport in porous media carbon-based catalysts. 

E.A. Mason and A.P. Malinauskas, Gas Transport in Porous Media The Dusty-Gas Model, Elsevier, Amsterdam, 1983. 

The description of multicomponent gas transport in porous media at arbitrary Knudsen numbers is very complicated, especially in the transition region of Kn 0.1 -10. This problem has never been solved rigorously. The situation remains extremely complex, even if the porous medium is regarded as composed of long, straight, circular channels of equal diameter. In these circumstances a consideration of simplified and limiting situations, which are better understood, is very important. Moreover, the approximate relationship between mass fluxes of the species and concentrations can be found by an appropriate combination of the corresponding relationships for simpler situations. 

Both the DGM and BFM capture many of the important properties of gas transport in porous media in a qualitatively correct way. They describe the limiting situations of small and large Knudsen number discussed above equally well. However, in some situations the model predictions are qualitatively different. The available experiments for the such questionable situations substantiate the BFM. The examples of the similar and different predictions are given in Chapter 9. 

Mason, E.A. Malinauskas, E.A.R (1983) Gas Transport in porous Media the Dusty-Gas Model, Amsterdam Elsevier. 

E.A.Mason, A.P.Malinausks, Gas transport in porous media The dusty-gas model, Elsevier, 1983... 

To model the transport of a multicomponent mixture through porous catalysts, flux relations should be developed. There are two geometrical models of gas transport in porous media with different trends of flux relations (Jackson, 1977). These models are the capillary network model and the dusty gas model. 

Ordinary molecular diffusion is generally recognized as the primary mechanism for gas transport in the unsaturated zone (19,, . Fundamental theory for ordinary diffusion according to Fick s first and second laws is presented in (22) more extensive theoretical discussions of gas transport in porous media are presented in (2 ... 

Hasmy A, Beurroies I, Bourret D et al (1995) Gas-Transport in Porous-Media - Simulations and Experiments on Partially Densified Aerogels. Europhysics Letters 29 567-572... 

Bravo, M.C. (2007) Effect of transition from slip to free molecular flow on gas transport in porous media. /. Appl. Phys., 102 (7), 074905. 

Mason EA, Malinauskas AP (1983) Gas transport in porous media the dusty-gas model. Chemical engineering monographs, vol 17. Elsevier, Amsterdam... 

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