Ethanol binaries

Nicklasson, M. and Brodin, A. (1984). The relationship between intrinsic dissolution rates and solubilities in the water-ethanol binary systehif. J. Pharm., 18 149-156. 

Figure 8. Water-ethanol binary adsorption isotherm on Alcoa H-152 alumina at 30°C.

Figure 3.4.3. VLB correlation of the -pentane and ethanol binary system at 373,398, and 423 K with the IPVDW mixing rule and the PRSV equation of state. Solid lines are the VLE results calculated with a different binary interaction parameter, ku, for each temperature. (The points are the data of Campbell, Wilsak, and Thodos 1987 data files for this system on the accompanying disk are PE373.DAT, PE398.DAT, and PE423.DAT.)...

In this study, the phase equilibrium in the binary mixtures that are expected to be found in the flash distillation was modeled with the Predictive Soave-Redlich-Kwong (PSRK) equation of state [4], using modified molecular parameters r and q. Five binary ethanol + congener mixtures were considered for new yield values for parameters r and q. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. Subsequently, the model was validated with the water + ethanol binary system, and the 1 -pentanol + ethanol + water, 1-propanol + ethanol + water, and furfural + ethanol + water ternary systems. 

E. Kiran and H. Pohler, Alternative solvents for cellulose derivatives Miscibility and density of cellulosic polymers in carbon dioxide + acetone and carbon dioxide + ethanol binary fluid mixtures, J. Supercrit. Fluids, 13, 135-147 (1998). 

Such a percolating network stmcture was also observed in the case of water-methanol and water-ethanol binary mixtures and is probably a general feature for these types of eosolvents which have both hydrophobic and hydrophilic moieties. 

However, there is a problem. Water and ethanol form an azeotrope, as mentioned before, but benzene also forms a binary azeotrope with ethanol. The benzene-ethanol binary azeotrope boils at 67.8°C and consists of 67.6% benzene and 32.4% ethanol. This means that as the benzene-water azeotrope is distilled, ethanol is also removed. An excess of ethanol is therefore essential. 

As for the pervaporation separation of binary mixtures, the calculation was done with respect to the binary system of water(i) / ethanol(j) mixtures. The water mole fraction in the permeate vapor, K/j, and the relative weight flux. IVrei> were calculated from Equations 6.135 and 6.145, for different Bj/B, values. The saturation vapor pressure and the vapor composition of water/ethanol binary mixtures for 40 C were adopted from the literature [243], and therefore the calculated values should correspond to pervaporation data for 40 C. All the results are summarized in Figure 6.25. 

Figure 18.8 (a) NIR absorption spectra of cyclohexane-ethanol binary mixtures with various mixing ratios. Numbers to the right indicate the mixing ratios of ethanol, (b) Difference spectra between the spectra for neighboring mole fractions for example, spectrum (0.9 —0.8) was obtained by subtracting the spectrum of ethanol mole fraction 0.8 from the spectrum of ethanol mole fraction 0.9. The spectra in both (a) and (b) have been offset to aid clarity. 

Figure 16 shows observed and calculated VLE and LLE for the system benzene-water-ethanol. In this unusually fortunate case, predictions based on the binary data alone (dashed line) are in good agreement with the experimental ternary data. Several factors contribute to this good agreement VLE data for the mis-... 

Fig. XI-11. Relation of adsorption from binary liquid mixtures to the separate vapor pressure adsorption isotherms, system ethanol-benzene-charcoal (n) separate mixed-vapor isotherms (b) calculated and observed adsorption from liquid mixtures. (From Ref. 143.)...

The first successful appHcation of heterogeneous azeotropic distillation was in 1902 (87) and involved using benzene to produce absolute alcohol from a binary mixture of ethanol and water. This batch process was patented in 1903 (88) and later converted to a continuous process (89). Good reviews of the early development and widespread appHcation of continuous azeotropic distillation in the prewar chemical industry are available (90). 

Table 13-1, based on the binary-system activity-coefficient-eqnation forms given in Table 13-3. Consistent Antoine vapor-pressure constants and liquid molar volumes are listed in Table 13-4. The Wilson equation is particularly useful for systems that are highly nonideal but do not undergo phase splitting, as exemplified by the ethanol-hexane system, whose activity coefficients are snown in Fig. 13-20. For systems such as this, in which activity coefficients in dilute regions may...

Three types of binary equilibrium cui ves are shown in Fig. 13-27. The y-x diagram is almost always plotted for the component that is the more volatile (denoted by the subscript 1) in the region where distillation is to take place. Cui ve A shows the most usual case, in which component 1 remains more volatile over the entire composition range. Cui ve B is typical of many systems (ethanol-water, for example) in which the component that is more volatile at lowvalues of X becomes less volatile than the other component at high values of X. The vapor and liquid compositions are identical for the homogeneous azeotrope where cui ve B crosses the 45° diagonal. A heterogeneous azeotrope is formed with two liquid phases by cui ve C,... 

Figure 8-4. Fraction of total base present as hydroxide as a function of the percentage of water in the binary solvent, lor ethanol-water and methanol-water mixtures. ...

Like Ag, Au also readily forms linear 2-coordinate complexes such as [AuX2] (X = Cl, Br, I) " and also the technologically important [Au(CN)2] . But it is much more susceptible to oxidation and to disproportionation into Au and Au which renders all its binary compounds, except AuCN, unstable to water. It is also more clearly a class b or soft metal with a preference for the heavier donor atoms P, As and S. Stable, linear complexes are obtained when tertiary phosphines reduce Au in ethanol. 

Adsorption phenomena from solutions onto sohd surfaces have been one of the important subjects in colloid and surface chemistry. Sophisticated application of adsorption has been demonstrated recently in the formation of self-assembhng monolayers and multilayers on various substrates [4,7], However, only a limited number of researchers have been devoted to the study of adsorption in binary hquid systems. The adsorption isotherm and colloidal stabihty measmement have been the main tools for these studies. The molecular level of characterization is needed to elucidate the phenomenon. We have employed the combination of smface forces measmement and Fomier transform infrared spectroscopy in attenuated total reflection (FTIR-ATR) to study the preferential (selective) adsorption of alcohol (methanol, ethanol, and propanol) onto glass surfaces from their binary mixtures with cyclohexane. Om studies have demonstrated the cluster formation of alcohol adsorbed on the surfaces and the long-range attraction associated with such adsorption. We may call these clusters macroclusters, because the thickness of the adsorbed alcohol layer is about 15 mn, which is quite large compared to the size of the alcohol. The following describes the results for the ethanol-cycohexane mixtures [10],... 

FIG. 4 FTIR-ATR spectra of ethanol on a silicon oxide surface in ethanol-cyclohexane binary liquids at various ethanol concentrations 0.0, 0.1, 0.3, 0.5, 1.0, and 2.0 mol%. 

Adrian et al. (2000) have reported a novel high-pressure liquid-liquid extraction process with reference to processing in biotechnology the example of cardiac glycosides (digitoxin and digoxin) is cited. A completely miscible, binary system of water and a hydrophobic organic solvent like ethanol can split into two liquid phases when a near-critical gas (e.g. CO2) is added. The near-critical C02/water/l-propanol system is reported, for which possibilities for industrial exploitation exist. 

Design a sieve plate column to perform this separation, for a feed rate of 10,000 kg/hour. Treat the feed as a binary mixture of ethanol and water. 

Increasing the excess of ethanol increases the conversion of acetic acid to ethyl acetate. To carry out the calculation more accurately would require activity coefficients to be calculated for the mixture (see Poling, Prausnitz and O Connell6 and Chapter 4). The activity coefficients depend on correlating coefficients between each binary pair in the mixture, the concentrations and temperature. 

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