Phase diagram water-butanol

Figure 1.10. Phase diagrams for butanol(1)-water(2) partially miscible mixture.

FIGURE 1.11 Phase diagrams for butanol(l)-water(2) partially miscible mixture (a) Tyxdiagram. (b) yxdiagram at 101.3 kPa. (For color version of this figure, the reader is referred to the online version of this book.)... 

M Woznyj, HD Ludemann. The pressure dependence of the phase diagram t-butanol/water. Z Naturforsch 40a 693-698, 1985. 

Fig. 6. Boiling point (a) and phase diagram (b) for the heterogeneous a2eotropic system, water/ 1-butanol at atmospheric pressure, yi, B and C, D are representative equiUbrium points Z is the a2eotropic point M and N are Hquid miscibility limits.

An example for a partially known ternary phase diagram is the sodium octane 1 -sulfonate/ 1-decanol/water system [61]. Figure 34 shows the isotropic areas L, and L2 for the water-rich surfactant phase with solubilized alcohol and for the solvent-rich surfactant phase with solubilized water, respectively. Furthermore, the lamellar neat phase D and the anisotropic hexagonal middle phase E are indicated (for systematics, cf. Ref. 62). For the quaternary sodium octane 1-sulfonate (A)/l-butanol (B)/n-tetradecane (0)/water (W) system, the tricritical point which characterizes the transition of three coexisting phases into one liquid phase is at 40.1°C A, 0.042 (mass parts) B, 0.958 (A + B = 56 wt %) O, 0.54 W, 0.46 [63]. For both the binary phase equilibrium dodecane... 

Figure 1. Temperature-composition phase diagrams of n-butanol (C4E0) and n-butoxyethanol (C4E1), respectively, with water, (redrawn from data in refs. 4 and 5.)...

Isoperibolic calorimetry measurements on the n-butanol/water and n-butoxyethanol/water systems have demonstrated the accuracy and convenience of this technique for measuring consolute phase compositions in amphiphile/water systems. Additional advantages of calorimetry over conventional phase diagram methods are that (1) calorimetry yields other useful thermodynamic parameters, such as excess enthalpies (2) calorimetry can be used for dark and opaque samples and (3) calorimetry does not depend on the bulk separation of conjugate fluids. Together, the present study and studies in the literature encompass all of the classes of compounds of the amphiphile/CO ydrocarbon/water systems that are encountered in... 

Most hydrophobic substances have low solubilities in water, and in the case of liquids, water is also sparingly soluble in the pure substance. Some substances such as butanols and chlorophenols display relatively high mutual solubilities. As temperature increases, these mutual solubilities increase until a point of total miscibility is reached at a critical solution temperature. Above this temperature, no mutual solubilities exist. A simple plot of solubility versus temperature thus ends at this critical point. At low temperatures near freezing, the phase diagram also become complex. Example of such systems have been reported for sec-butyl alcohol (2-butanol) by Ochi et al. (1996) and for chlorophenols by Jaoui et al. (1999). 

Figure 3. Phase diagrams of the system water sodium dodecyl sulphate/alkanols benzene (a) ethanol (b) 2-propanol (c) 1-propanol(d) 1-butanol (e) 1-pentanol (f) 1-hexanol (g) 1-heptanol.

Under some circumstances, (liquid + liquid) equilibria occur under conditions where it is also important to consider the (vapor + liquid) effects. For example, Figure 14.8 shows the phase diagram for (water + 1-butanol) at p = 101.3 kPa. Lines ac and be give the normal boiling temperatures for the mixtures. Since... 

As a last example, we consider the binary phase diagram of water and 1-butanol (Figs. 6.16 and 6.17). There is a negative heat of mixing, HE, but a positive excess Gibbs energy of mixing, GE. The infinite dilution activity coefficient of 1-butanol in water is very... 

Fig. 8.1. Original diagrams of the first COSMO-RS phase-diagram calculations by Iven Clausen [96] for four alcohol-water mixtures (methanol at 60 C, ethanol at 55 °C, 1-propanol at 60 °C and 1-butanol...

As a typical example from industrial practice we consider the simulation of a process with the reaction of methylphosphinic acid and butanol to methylphosphinic acid butyl ester and water, which was modeled by Gordana Hofmann-Jovic at InfraServ Knapsack [C28]. Because of the lack of experimental data for the binary systems with phosphorous compounds, COSMO-RS was used for the prediction of the binary activity coefficients. Then the results were fitted by an NRTL equation and the entire process was modeled by a commercial process simulator. The resulting phase diagrams were in close agreement with experimental measurements obtained later (Fig. 8.2). 

Fig. 8.2. Simulation of the isobaric phase diagram for the reacting system methylphosphinic acid + butanol -+ methylphosphinic acid butyl ester plus water based on COSMO-RS predictions [C28].

At atmospheric pressure, the n-butanol-water system exhibits a minimum boiling azeotrope and partial miscibility, and hence a binary heterogeneous azeotrope. Figure 1.8 shows the Tyx and Pyx phase diagrams for l-propanol(l)-water(2) azeotropic mixture obtained from the Aspen Plus simulator using the NRTL activity coefficient model. 

The phase diagram of the quaternary system, n-tetradecane, water, A-B-A block copol3nner (where A Is poly— (12-hydroxystearlc acid) and B Is poly(ethylene oxide)) and n-butanol was Investigated at 7, 23 and 47 C. Two A-B-A polymer concentrations of 10 and 20Z were used. 

Consider the separation of water from n-butanol. The phase behavior for this mixture is quite complex. There is a minimum-boiling azeotrope formed as well as a liquid-liquid phase separation when the liquid is cooled enough. Figure 10 is a sketch of the general shape of the phase behavior for this system. (It is not an accurately drawn phase diagram.)... 

Figure 4. Comparison of the phase diagrams determined from the refractive index measurements with that obtained by the visual method. The weight fraction w is the concentration variable. Empty symbols are used, when the compositions are estimated from refractive index data (Cemim+BFJ in 1-butanol (A), 1-pentanol (y), 2-butanol (0), and 2-pentanol (<)), full symbols, when the data are obtained by the visual method observing the separation temperature in samples of different composition (Gemini+ in water ( ), 1-propanol (O). 1-butanol (A), 2-butanol (y), 1-pentanol (0), 2-pentanol (<), and 1-hexanol (>)).

Figure 1. Phase diagram for a mixture of water, toluene, SDS, butanol (water/SDS ratio 1.25).

Typical non-ideal binaries forming two liquid phases is the n-butanol-water system at 1 atmospheric pressure. A solution with approximately 2 mole% n-butanol in water exists at equilibrium with another liquid phase with approximately 38 mole% n-butanol in water. The fugacity of n-butanol in both phases is about 0.48. A phase diagram of this binary is illustrated in Figure 1.16. The curves, which closely match the experimental data, are based on calculations using the NRTL equation for activity coefficients. 

Figure J+. Binary liquid-phase diagram for 1-butanol-water...

Figure 3.7. Minimum-boiling-point (two liquid phases) water-n-butanol system, (a) Partial and total pressures at 100°C. (b) Vapor-liquid equilibria at 101 kPa. (c) Phase diagram at 101 kPa pressure. [Adapted from O. A. Hougen, K. M. Watson, and R. A. Ragatz, Chemical Process Principles, Part II, 2nd ed., John Wiley and Sons, N.Y. (1959).]...

Figure 17 Solid-liquid phase diagram of the system water-ter t-butanol X = mol fraction concentration and P denotes a probable peritectic transition. A.2H2O is a stable crystalline hydrate, with = 0.55°C. The two eutectic points correspond to —8.52°C (x = 0.065) and —4.55°C (x = 0.62). Adapted from Takaizumf ...

Figure 1 Pseudo ternary phase diagrams at room temperature of (a) quaternary systems containing lecithin, butanol, isopropyl myristate, and water or (b) a 10 wt% aqueous solution of sodium salicylate, at a lecithin/butanol ratio of 1 1. (Adapted from Ref. 9.)...

Most microemulsions are made with four components. In this case, Eq. 2.20 cannot be used, unless a pseudo-component is defined, such as a given ratio of surfactant to alcoholic cosurfactant. This active mixture is considered as the third component and is placed at the C apex. Figure 2.16 shows the phase diagram of the ternary system water/heptane/sodium bis (2-ethylhexyl) sulfosuccinate (Aerosol OT or AOT) [35]. AOT is an anionic surfactant able to form W/0 microemulsions without the need of a cosurfactant. Figure 2.17 shows the phase diagram of the pseudo-ternary system water/heptane/(CTAB + w-butanol) [31]. CTAB is a cationic surfactant that needs to be associated with a cosur ctant to form microemulsions. The ratio CTAB/butanol was constant (1/1 w/w) for all compositions represented in the phase diagram. The hatched areas corres-... 

Interfacial tension has been deduced from the spectrum of the light scattered by the interface. The results are relative to water-toluene-sodium dodecyl sulfate (SDS)-butanol mixtures either in the two phase, or in the three phase region of the phase diagram. Values down to 10 dynes/cm have been measured. Measurements down to 10 - 10 6 dynes/cm are expected to be achievable with this technique. 

The samples were made using toluene as oil and a mixture of sodium dodecyl sulfate (SDS) and butanol as emulsifier. The phase diagram of this system was extensively studied by Lalanne et al. (8). The composition of samples is indicated in Table 1. Their densities, viscosities and refractive indices are reported in Table 2. The three-phase samples were obtained by adding salt into water (the limits of the three-phase domain for the samples of Table 1 were 5.8% - 7.8% of salt in water). 

Figure 4 Phase diagram of the tert-butanol (TBA)/water system plotted on % (w/w) basis. Mole fractions are listed for eutectic A and B and the pure hydrate X is tert-butanol concentration on mole fraction basis [28].

Fig. 1 Phase diagrams of the sugar syrfactant wo-butanol/oil/water systems EMGD - diethylene glycol monoethyl ether, o/w - oil-in-water microemulsion, w/o - water-in-oil microemulsion, he. - becontinous microemulsion, LC - liquid crystals, 2F - two phase region...

FIG. 11 Phase diagram for the system dodecane + butanol 1 1 (w/w)-Brij 97-water at 27°C. Along the XB4 water dilution line, the Brij 97/butanol/dodecane weight ratio is 4 3 3. LC designates the liquid crystalline phase region. (From Ref. 67.)... 

FIG. 13 Phase diagram for the system dodecane-butanol-S-1570-water. No attempt was made to further identify the liquid crystals (not shown) or any other phase within the two-phase area. The dashed lines represent the water dilution lines along which the dodecane/butanol/S-1570 weight ratios are kept constant at 1 1 0.94 (dilution line 32) and 1 1 1.5 (dilution line 43), respectively. (From Ref. 42.)... 

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