Stefan equation for binary mixtures

Example 6.1 Maxwell-Stefan equation for binary mixtures For an application of the Maxwell-Stefan description of diffusion, we consider a binary isotropic mixture with components 1 and 2. To solve the mass balance equations, the diffusion flow has to be known. The binary diffusion flow without the electromagnetic field and external forces is given by 

Thermodynamic correction factor Y is defined using the Gibbs-Duhem relation 

The thermodynamic factor is a measure of deviation from ideal behavior, and equal to unity for ideal systems. Equation (6.24) can be rearranged as 

For a binary system, grad w, is related to grad x1 by using the summation relation x, +, r2 = 1 and M = M]x] + M2x2, and we obtain 

A solution is a condensed phase of several components, which may be subject to strong intermolecular forces. Despite the fundamental differences between solutions and gases, some laws for solutions are analogous to those for gases. If the solution is sufficiently dilute, the osmotic pressure is described by an equation similar to that for an ideal gas, and ideal solutions are treated as a special case of ideal gas. 

---

Example 6.1 Maxwell-Stefan equation for binary mixtures... 

---