Trajectory Bundles of Sharp Reversible Distillation

The analysis of the reversible distillation of ideal mixtures has led to important practical results. The use of flowsheets of the same type as those shown in Fig. 4.4 but consisting of real adiabatic columns (i.e., columns with finite numbers of separation stages), without intermediate input of heat and cold and with product columns joined into one complex column (Petlyuk, Platonov, Slavinskii, 1965), allows energy consumption for separation to be reduced by thirty to forty percent. 

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Let s examine now the structure of trajectory bundles of sharp reversible distillation for the intermediate (extractive) section of the column with two feedings at separation of different types of azeotropic mixtures, the way we did it for the top and the bottom sections (Fig. 4.21). While composing these diagrams, we used, just as we did before, the data on the phase equilibrium coefficients of present and absent components at the sides of the concentration triangle and the general regularities of the location of the trajectory bundles of sharp reversible distillation. 

Figure 4.16. Bundles of sharp reversible stripping trajectories in region reversible distillation Regjigy j for the acetone(l)-benzene(2)-chloroform(3)-tolnene(4) mixture (a) node is component 1, (b) node is azeotrope 13, and (c) nodes are component 1 and azeotrope 13.

I. Define the main notions (1) region of reversible distillation of top Reg g bottom Reg -e, and intermediate sections Reg g (2) regions of trajectory tear-off Reg and Reg (3) region of possible product points of sharp reversible distillation Reg, Reg, and Reg and (4) node of trajectory bundle of reversible distillation Nrev-... 

The analysis of the thermodynamically reversible process of distillation for multicomponent azeotropic mixtures was made considerably later. Restrictions at sharp reversible distillation were revealed (Petlyuk, 1978), and trajectory bundles at sharp and nonsharp reversible distillation of three-component azeotropic mixtures were investigated (Petlyuk, Serafimov, Avet yan, Vinogradova, 1981a, 1981b). 

Locations of trajectories bundles Regr. of node points of these bundles Nrev, and of possible product segments Reg Wd Regf can be shown in diagrams of three-component azeotropic mixtures sharp reversible distillation for various types of such mixtures (Fig. 4.11). 

In other words, for sharp separation in a two-section column it is necessary that the feed point belongs to the intersection of true bundles of reversible distillation trajectories of the two sections Xf e (Regrev.r Reg v. ) (Fig. 4.10). The reversible... 

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