Separation and Reflux Ratio Specified

The separation is specified in terms of the composition of one component in the distillate and bottoms, F, and (The subscripts refer to stages. When component subscripts are dropped, implied reference is to the more volatile component). The separation may alternatively be specified in terms of variables that are functions of Fj and Xf/. The reflux ratio expresses relative flow rates of liquid and vapor within the column. It may be specified in terms of V, L or )/, or a function thereof such as L/V)  

The assumed feed tray temperature may now be checked and, if necessary, the (/-line is redrawn using the updated slope. The above procedure is then repeated for the new (/-line slope. To check the feed tray temperature, it is necessary to make use of the vapor-liquid equilibrium data from which the equilibrium curve was drawn. 

To complete the column solution, the product rates are computed from a total material balance and one component balance around the column  

The values of and are determined from their given ratio and a material balance on the condenser, D=V L. The stripping section flows, V,. and L, can be calculated from Equations 5.16 and 5.17. 

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