Separation of Multicomponent Mixtures at Total Reflux

The topic of total reflux is considered briefly in this chapter for the purpose of developing the well-known Fenske equation (Ref. 4) which is needed in Chaps. 2 and 3. A more general treatment of the subject area of total reflux is presented in Chap. 7. 

From the standpoint of design, the most useful definition of total reflux consists of the one in which the total flow rates [Lj (j = 1, 2,. .., N — 1), Vj (j = 2,. .., N)] are unbounded while the feed and product rates are finite. More precisely 

As a consequence of the results given by Eqs. (1-44) and (1-45) it follows that the component-material balance is given by 

For stage 3, the component-material balance and equilibrium component i are as follows relationship for 

Continuation of this procedure for stages j = 4 through N (the reboiler) yields 

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