Azeotropes ternary systems

The simplest form of ternary RCM, as exemplified for the ideal normal-paraffin system of pentane-hexane-heptane, is illustrated in Fig. 13-58 7, using a right-triangle diagram. Maps for all other non-azeotropic ternary mixtures are qiiahtatively similar. Each of the infinite number of possible residue curves originates at the pentane vertex, travels toward and then away from the hexane vertex, and terminates at the heptane vertex. 

Torres-Marchal [110] and [111] present a detailed graphical solution for multicomponent ternary systems that can be useful to establish the important parameters prior to undertaking a more rigorous solution with a computer program. This technique can be used for azeotropic mixtures, close-boiling mixtures and similar situations. 

All of the discussion in this chapter has so far related to binary or ternary systems. It will most often be the case that systems involving azeotropic behavior will also be multicomponent. The concepts developed here for ternary... 

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]. 

Lecat (32) is responsible for most of the azeotropic data on binary and ternary systems. Recently, however, Horsley (25) has compiled extensive tables of azeotropic data, thus making the information more available. These experimental data may be supplemented by estimations of the azeotropic composition and behavior of unknown systems by several reasonably reliable methods. Graphical methods, based on curves developed from experimental data, have been proposed by Lecat (82), Mair et al. (.ffi), Horsley (26), Skol-... 

IEC 36, 871-5(1944) (Azeotropic distn) (14 refs) 4)R.H. Ewell L.M. Welch, IEC 37, 1224-31(l945)(Rectification in ternary systems contg binary azeotropes) (8 refs) 5)L.H. Horsley, Anal Chem 19, 50 600(1947)... 

The displacement of the azeotropic composition by progressive addition of magnesium nitrate has been shown in Table I above. Vapor-liquid equilibria have been determined (3, 4). Figure 5 depicts equilibrium vapor compositions in the ternary system at the boiling point, while Figure 6 shows boiling points in the system at 760 mm Hg. 

Fig. 4.2. Potential singular point surfaces (dashed-dotted curve) for an ideal ternary system with single reaction A + B C. (a) Ellipse-type system (b) hyperbola-type system. RA = reactive azeotrope solid curve = chemical equilibrium surface.

If the liquid mixture is extremely non-ideal, liquid phase splitting will occur. Here, we first consider the hypothetical ternary system. The physical properties are adopted from Ung and Doherty [17] and Qi et al. [10]. The catalyst is assumed to have equal activity in the two liquid phases. The corresponding PSPS is depicted in Fig. 4.5, together with the liquid-liquid envelope and the chemical equilibrium surface. The PSPS passes through the vertices of pure A, B, C, and the stoichiometric pole Jt. The shape of the PSPS is affected significantly by the liquid phase non-idealities. As a result, there are three binary nonreactive azeotropes located on... 

Figure 3.10 Residue curve maps for nonideal ternary systems involving azeotropes.

X = Di(jkli)/D(jkl) (5.13). The sign of the latter is exactly the same as Ind(x ) when the three-component azeotrope in the system (jkl) is the node or focus, and its sign is opposite to the sign of lnd(x ) when the above azeotrope is the saddle. The separatrix surface inside the tetrahedron surely passes through the azeotrope located on its face when in the ternary system corresponding to this face such an azeotrope is the saddle. 

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. 

Both methylethylketone (MEK) andmethylisopropylketone (MIPK) form minimum-boihng azeotropes with water (Fig. 13-58b). In this ternary system, a separatrix connects the binary azeotropes and divides the RCM into two regions. The high-boiHng node of Region I is pure water, while the low-boiHng node is the MEK-water azeotrope. 

They performed binary system experiments for each of the pairs in the ternary system. It was found that glycol can move the azeotrope point and therefore, enhance the separation process. Sheikholeslamzadeh et al. have used both the NRTL-SAC and UNIFAC models to perform phase calculations and assess the capacity of the mentioned models in the prediction of binary and ternary systems containing glycol and alcohols [20],... 

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