Ternary systems distillation

Figure 12.11 superimposes distillation lines and residue curves for the same ternary systems. Figure 12.11a shows the system n-pentane, n-hexane and n -heptane, which is a relatively wide boiling mixture. It can be observed in Figure 12.11a that there are significant differences between the paths of the distillation lines and the residue curves. By... 

For a simple distillation column separating a ternary system, once the feed composition has been fixed, three-product component compositions can be specified, with at least one for each product. The remaining compositions will be determined by colinearity in the ternary diagram. For a binary distillation only two product compositions can be specified independently, one in each product. Once the mass balance has been specified, the column pressure, reflux (or reboil ratio) and feed condition must also be specified. 

The VLB was also measured for binary and ternary systems of [ethanol + [C2Cilm][C2S04] and [ethanol + ethyl ferf-butyl ether + [C2Cilm][C2S04] at 101.3 kPa [151]. This ternary system does not exhibit a ternary azeotrope. The possibility of [C2Cilm][C2S04] use as a solvenf in liquid-liquid extraction or as an entrainer in extractive distillation for fhe separation of the mixture ethanol/ethyl fcrf-butyl ether was discussed [151]. 

Since in an extractive distillation process based on this ternary system the extractive agent is nonvolatile and remains in the liquid phase, and since because of the similarity of the molar latent heats of nitric acid and water there is substantially constant molar liquid overflow, the mole fraction of magnesium nitrate remains almost constant throughout the process. It is appropriate to represent the equilibrium situation as a pseudo-binary system for each magnesium nitrate concentration, and Figure 7 shows vapor-liquid equilibria on a nitric acid-water basis at a series of magnesium nitrate concentrations from zero to 0.25 mole fraction in the liquid phase. 

Method I.—The apparatus described in Preparation 1 is fitted up, a 500-c.c. flask being used, and 30 gms. (1 mol.) of finely powdered tartaric acid, 150 gms. (excess) of absolute alcohol, and 50 gms. of crystallised benzene placed in the flask. The object of the benzene is to help to volatilise the water produced by forming with it and the alcohol the low boiling ternary system—alcohol-benzene-water. The iron tube is packed with small lumps of good quicklime, and is heated to a temperature of 90°. The mixture in the flask is boiled, a few pieces of porous porcelain being added to promote steady ebullition. Esterification proceeds almost to completion, owing to the removal by the quicklime of the water formed. After 6 hours, the liquid in the flask, which will have become quite viscid owing to the formation of the ester, is distilled on a water bath until all the benzene and excess of alcohol have been removed the residue is fractionated from a metal bath under reduced pressure. 

A ternary system with a hyperbola-type PSPS is used to investigate the influence of membrane permeation (Fig. 4.32). The applied parameters (ct,A and Kg) and the corresponding eigenvalues of the matrix [A] are summarized in Tab. 4.3. For comparison, again the PSPS for the reactive distillation process is given in Fig. 4.32(a). The effect of a selective membrane with a diagonal [/e]-matrix is illustrated in Fig. 4.32(b, d). 

Figure A.2 (left) shows the construction of a distillation for an ideal ternary system in which A and C are the light (stable node) and the heavy (unstable node) boilers, while B is an intermediate boiler (saddle). The initial point xiA produces the vapor y, that by condensation gives a liquid with the same composition such that the next point is xi 2 = y,, etc. Accordingly, the distillation line describes the evolution of composition on the stages of a distillation column at equilibrium and total reflux from the bottom to the top. The slope of a distillation line is a measure of the relative volatility of components. The analysis in RCM or DCM leads to the same results.

This ternary azeotropic distillation program uses a special system of utility subroutines with programmed initialization. Eight main controls, KNTRL, are used with various options on each. Four parameter options are built into the program, but the values are changed by the user by using PRMTR cards. Twenty-one DATA cards allow the user to give the pertinent conditions and specifications for the separation to be calculated. 

This study was undertaken to obtain the necessary vapor-liquid equilibrium data and to determine the distillation requirements for recovering solvent for reuse from the solvent-water mixture obtained from adsorber regeneration. Previous binary vapor-liquid equilibrium data (2, 3) indicated two binary azeotropes (water-THF and water-MEK) and a two phase region (water-MEK). The ternary system was thus expected to be highly nonideal. 

Table 1. Results for the ternary system ethanol/water/l-pentanol (DISTIL).

Biddulph and Kalbassi (1988) investigated the distillation of the ternary system methanol(l)-l-propanol(2)-water(3). In separate experiments they determined the numbers of transfer units for each binary pair that makes up the ternary system. Estimate the number of transfer units for the ternary system at total reflux if the composition of the liquid leaving the tray is... 

Estimate the tray efficiency in the distillation of the ternary system methanol(l)-l-pro-panol(2)-water(3) considered in Examples 12.2.1 and 13.3.1. 

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