Product Composition Regions for Finite and Infinite Columns

Dimensionality of Product Composition Regions for Finite and Infinite Columns 

From Eq. (3.2) and the equation of material balance of the column, a simple mathematic model follows  

From the system of Eqs. (3.3) (3.4), it follows that at a given feed composition Zf and at a fixed field of phase equilibrium coefficients, Ki = fi(T, P, xi. x ) separation products compositions xd and xb depend on only two parameters -relative withdrawal of one of the products D/Fand amount of theoretical plates N. At infinite reflux, the location of feeding plate does not influence the compositions of distillation products nor profile of concentrations. This is quite understandable -the external flow coming to the feeding plate is infinitely small in comparison with internal flows in the column. 

Obviously, at a flnite number of stages, the distillation trajectory under the infinite reflux should he in one of the c-lines and cannot pass through a stationary point of the concentration simplex, start or end in it. At the infinite number of 

Trajectories of Distillation in Infinite Columns Under Infinite Reflux 

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