Water-2-propanol mixtures

The feed compositions and products of each of these strategic separations remain ill-defined. The unspecified 2-propanol—water mixture, the input to each strategic separation, could be but is not necessarily the original feed composition. The MSA composition (pure hexane in this case) is such that one of the products of the strategic separation is in region II, ie, the strategic separation crosses the distillation boundary. Two opportunistic distillations from... 

Example 4.5 2-Propanol (isopropanol) and water form an azeotropic mixture at a particular liquid composition that results in the vapor and liquid compositions being equal. Vapor-liquid equilibrium for 2-propanol-water mixtures can be predicted by the Wilson equation. Vapor pressure coefficients in bar with temperature in Kelvin for the Antoine equation are given in Table 4.113. Data for the Wilson equation are given in Table 4.126. Assume the gas constant R = 8.3145 kJ-kmol 1-K 1. Determine the azeotropic composition at 1 atm. 

Transition-metal catalysts are, in general, more active than the MPVO catalysts in the reduction of ketones via hydrogen transfer. Especially, upon the introduction of a small amount of base into the reaction mixture, TOFs of transition-metal catalysts are typically five- to 10-fold higher than those of MPVO catalysts (see Table 20.7, MPVO catalysts entries 1-20, transition-metal catalysts entries 21-53). The transition-metal catalysts are less sensitive to moisture than MPVO catalysts. Transition metal-catalyzed reactions are frequently carried out in 2-propanol/water mixtures. Successful transition-metal catalysts for transfer hydrogenations are based not only on iridium, rhodium or ruthenium ions but also on nickel [93], rhenium [94] and osmium [95]. It has been reported that... 

The thermodynamic excess functions for the 2-propanol-water mixture and the effects of lithium chloride, lithium bromide, and calcium chloride on the phase equilibrium for this binary system have been studied in previous papers (2, 3). In this paper, the effects of lithium perchlorate on the vapor-liquid equilibrium at 75°, 50°, and 25°C for the 2-propanol-water system have been obtained by using a dynamic method with a modified Othmer still. This system was selected because lithium perchlorate may be more soluble in alcohol than in water (4). 

The present paper is devoted to the local composition of liquid mixtures calculated in the framework of the Kirkwood—Buff theory of solutions. A new method is suggested to calculate the excess (or deficit) number of various molecules around a selected (central) molecule in binary and multicomponent liquid mixtures in terms of measurable macroscopic thermodynamic quantities, such as the derivatives of the chemical potentials with respect to concentrations, the isothermal compressibility, and the partial molar volumes. This method accounts for an inaccessible volume due to the presence of a central molecule and is applied to binary and ternary mixtures. For the ideal binary mixture it is shown that because of the difference in the volumes of the pure components there is an excess (or deficit) number of different molecules around a central molecule. The excess (or deficit) becomes zero when the components of the ideal binary mixture have the same volume. The new method is also applied to methanol + water and 2-propanol -I- water mixtures. In the case of the 2-propanol + water mixture, the new method, in contrast to the other ones, indicates that clusters dominated by 2-propanol disappear at high alcohol mole fractions, in agreement with experimental observations. Finally, it is shown that the application of the new procedure to the ternary mixture water/protein/cosolvent at infinite dilution of the protein led to almost the same results as the methods involving a reference state. 

It is clear (see Figures 1—3) that the excesses (or deficits) calculated with the new eq 13 are always very different from those obtained with eq 1. However, eq 13 and eqs 3 and 4 provide comparable results for binary mixtures when the molar volumes of the components are approximately the same. The results obtained using eq 1 and those obtained from eq 13 for methanoFwater and 2-propanoFwater mixtures are very different. In contrast to the methods based on a reference state, the new method predicts that the alcohols are preferentially hydrated at high alcohol mole fractions. For the 2-propanol/water mixtures there are experimental observations which support this prediction. 

For the model validation and the analysis of the heat integration in the hybrid pervaporation distillation process, a laboratory plant has been built at the TU -Berlin and prepared for the connection with the distillation column (see fig. 3). With this plant experiments with a flat PVA-based (Polyvinylalcohol from GKSS) hydrophilic membrane have been done. A heat exchanger has been built within the pervaporation module. The temperature in the heat exchanger has been necessary to avoid the temperature drop between feed and retentate streams in the pervaporation process. In the process a 2-Propanol/ Water mixture has been separated. The concentration of 2-Propanol in the feed is between 80 and 90 % in weight and the temperature range in the experiments was between 70 and 90°C. The feed flow is turbulent and the system fully insulated to avoid heat looses. The pressure in the permeate side has been kept at 30 mbar and the feed pressure at 1.5 bar. 

NiO was dispersed in a 0.2 M solution of ZrOfNO lj in a 2-propanol-water mixture (4 1 molar ratio). The temperature was slowly raised to 80°C within 1 h while stirring. The temperature was kept at 80°C for 1 h. The powder was washed with 2-propanol, dried, and calcined at 900°C for 3 h. 

The kinetics of other colloidal Pt-particles assisted redox reactions have also been investigated. Consider, for example, the photoinduced reduction of benzophenone3401 in a 2-propanol-water mixture which leads to the formation of ketyl radicals via the reaction... 

When lactate is used as a chiral auxiliary, the proximity of the enolic hydroxyl group and the carboxyl of the lactate induces an interaction between the functional groups in the photodienol. Therefore, a surprising solvent effect, and even a reversal of the diastereoselectivity with the content of 2-propanol in water, was reported [53]. Except for lactate 8f in methanol and 2-propanol/water mixtures, it was possible to correlate the chirality of the new asymmetric center with the configuration of the lactyl chiral auxiliary. When (S)-lactyl derivatives were examined, models indicated that the S-configuration of the new chiral center can be deduced from a sterically easier approach of the carboxylate group at the re face of the a-carbon of the dienol. 

Propanol-water mixtures are still combustible in a 70/30 ratio, but not com-... 

VOLUMES, REFRACTIVE INDICES, VISCOSITIES, DIELECTRIC CONSTANTS, AND SURFACE TENSIONS OF l,1,1,3,3,3-HEXAFLUORO-2-PROPANOL-WATER MIXTURES. 

Figure 5.5.3. Surface tension of 2-propanol-water mixtures. The smooth line is drawn with eq. 5.5.26. (Reproduced with permission from the Journal of Solution Chemistry, reference 14.)...

Mobile phase 2-Propanol-water mixtures optimized by the window diagrams method. 

The monomer purity and reaction temperature were found to be vital factors in the polymerizations. From the viewpoint of obtaining high molecular weight polymers, repeated recrystallization of the sulfonated monomers was carried out in 2-propanol/water mixtures to yield polymerization grade monomers, which were dried in vacuum at 120°C for 12 h before the polymerization. 

Nafion/PTFE composite membranes were fabricated [17] by impregnation of a porons PI LE film with a solution of Nafion in a 2-propanol/water mixture. After solvent evaporation, the impregnated film was annealed at 120°C for 1 h. The resultant membrane was 20 pm in thickness, with a proton conductivity of 0.033 S cm at 25°C (30% that of Nafion 117), while the methanol flux was 4.43x10 mol cm s (as compared with 1.62x10 mol cm s for Nafion 117 and 6.20x10 mol cm s for Nafion 112). DMEC performance of the composite membrane, measured at 70 C with 2.0 M methanol feed and pure oxygen, was superior to that of both Nafion 112 and 117. 

Instead of using benzene or toluene as a solvent for styrene/DVB in the grafting solution, polar solvents, such as methanol, 2-propanol, and 2-propanol/water mixtures, brought about substantially enhanced grafting kinetics, because these nonsolvents do not swell the grafted polystyrene and thereby result in extended radical lifetimes. 

Figure 8.2.11. Solvent effect on the decomposition of N-chloroleucine in 2-propanol-water mixtures. The smooth curve is drawn with eq. 8.2.49. [Adapted, by permission, from J.M. LePree and K.A. Connors, J.

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