Membrane Separation of a Ternary Mixture
Consider a hypothetical ternary mixture of components , , and fed into a membrane separation module. The feed composition is mole % of , mole % of , and mole % of . This Demonstration computes the permeate (, , and ), and reject compositions (, , and ) for user-set values of the reject mole fraction of component . The membrane area and stage cut, , are also calculated. Complete mixing is assumed. The built-in Mathematica function FindRoot is used to readily solve seven simultaneous equations with seven unknowns. Values of the thickness of the membrane, pressures in both sides of the membrane, feed flow rate, and the permeabilities of the components are all taken from .
 C. J. Geankoplis, Transport Processes and Unit Operations, 3rd ed., Englewood Cliffs, NJ: Prentice–Hall, 1993.