EQUILIBRIUM IN POROUS SORBENTS

Recall that the ideal separation factor for this example is ajd = 5.224. For the perfect mixing case of Example 9.2, it was found that the stage separation factor was always smaller that the ideal separation factor. Such is not the case for crossflow, where as increases monotonically with 0 reaching values that can be much higher than aid. 

Calculation of the degree of separation of a binary mixture in a membrane module for cocurrent or countercurrent flow patterns involves the numerical solution of a system of two nonlinear, coupled, ordinary differential equations (Walawender and Stem, 1972). For a given cut, the best separation is achieved with countercurrent flow, followed by crossflow, cocurrent flow, and perfect mixing, in that order. The crossflow case is considered to be a good, conservative estimate of module membrane performance (Seader and Henley, 2006). 

Your objectives in studying this section are to be able to  

Define the concept of an adsorption isotherm, and describe the characteristics of the four general types of isotherms. 

Fit experimental data to the Langmuir and Freundlich adsorption isotherm models. 

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