Mass transfer modeling pervaporation

The commonly used mass transfer in pervaporation is the solution-diffusion model — a transfer occurs in three steps (Figure 21.13). 

Pervaporation has been the subject of many papers for several decades. The literature is quite extensive with many papers and several books on the subject. The 1991 book edited by Huang gives 262 citations in the first chapter. The book by Rautenbach and Albrect, written in 1989, has a chapter on pervaporation. There are many papers that discuss the fundamentals of diffusion, adsorption, evaporation, and membrane characteristics. Some papers develop detailed mass-transfer models. A number of papers discuss design considerations and present comparative economic studies of pervaporation vctsus alternatives such as distillation. 

Finally, it is important to notice the effect of the support in the pervaporation flux, analyzed by Bruijn et al. [117] who proposed a model and evaluated the contribution of the support layer to the overall resistance for mass transfer in the selected literature data. They found that in many cases, the support is limiting the flux the permeation mechanism through the support corresponds to a Knudsen diffusion mechanism, which makes improvements in the porosity, tortuosity, pore diameter, and thickness necessary for an increase in the pervaporation flux. 

J. Lipzinski, G. Tragardh, 2001, Modelling of Pervaporation, Models to analyze and prediet the mass transfer transport in Pervaporation, Separation and Purifieation Methods, vol. 30(1), 49-25. 

Finally, it is important to notice the effect of the support in the pervaporation flux, analyzed by de Bruijn et al. [164] who proposed a model and evaluated the contribution of the support layer to the overall resistance for mass transfer in the selected literature data. They found that in many cases, the support is limiting the flux the permeation mechanism through the support corresponds to a Knudsen diffusion mechanism, which makes improvements in the porosity, tortuosity, pore diameter, and thickness necessary for an increase in the pervaporation flux. In fact, the researchers of Bussan Nanotech Research Institute Inc. (BNR), Sato et al. [165], designed and patented an appropriate asymmetric ceramic porous support to suppress pressure drop, and in this case, the water flux increased dramatically compared to previous reported results. Wang et al. [166] have clearly shown that the flux of the membranes increased with the porosity of the hollow fiber supports. In spite of the thin 1 pm zeolite layer, prepared by Zhou et al. [167], the flux enhancement compared to layers 10 times thicker [168] was not significant. 

The quantitative relation between solution concentration and MIMS response can be established by analyzing the mass transfer of the analyte through the semipermeable membrane. The mass transfer in the capillary probe membrane through pervaporation can be modeled as a hollow rod using Pick s law [18] ... 

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