Four-component mixtures ideal

Product Composition Regions for Ideal Four-Component Mixtures... 

Figure 3.4. (a) Product region under infinite reflux for given xp and different number of trays and D/F. Ideal four-component mixture > K2 > > K4),... 

Figure 4.2. Location of reversible section trajectories of an ideal four-component mixture at sharp split and liquid-vapor tie-line of the feed point (xp - yp).

Locations of reversible distillation trajectories depends on position of pseudoproduct point (i.e., on compositions and on flow rates of feeds and of separation products, as is seen from Eq. [6.3]). Difference from the top and bottom sections appears, when the pseudoproduct point of the intermediate section is located outside the concentration simplex (i.e., if concentrations of some components x j)i obtained from Eq. [6.3], are smaller than zero or bigger than one), which in particular takes place, if concentration of admixture components in separation products are small components (i.e., at sharp separation in the whole column). The location of reversible distillation trajectories of the intermediate sections at x j i < 0 or x, > 1 differs in principle from location of ones for top and bottom sections, as is seen from Fig. 6.3 for ideal three-component mixture (Ki > K2 > K3) and from Fig. 6.4 for ideal four-component mixture (Ki > K2 > K3 > K4). 

Figure 6.4. Reversible distillation trajectories of ideal four-component mixtures (Ki > K2 > K3 > K4) for intermediate section of two-feed column (a) <0 (b) 4 < 0. Solid...

We now examine the structure of intermediate section trajectory bundle for four-component mixtures at the example of ideal mixture (ATi > K2 > > K4). 

We notice that the wavenumbers have been chosen judiciously, in that each compound has a significant absorbance at one of these, while contributing relatively little at the other wavenumbers. Indeed, the four components have absorption peaks at precisely one of these wavenumbers, and the mixture shows four almost baseline-separated absorption peaks, one for each component. This, then, is an ideal example, of which the solution is, at least in principle, quite straightforward we need to solve four simultaneous equations in four unknowns. 

As an example of the application of the phase rule with reaction, consider a mixture of four components in which only two participate in a reaction. If all components are present in the gas phase, then F = 4 + 2- l- l=4. Hence, only four intensive variables are independently variable (e.g., T, P, yi, and y2, or P, y, y, and y ) if the vapor is ideal. For example, the independent reaction yields the following form of the equilibrium constant ... 

The four-component gas mixture behaves ideally at moderately low pressures, and the sum of stoichiometric coefficients v, is not zero. Hence,... 

Problem 11.12 a) Assuming that methanol (1), ethanol (2), acetonitrile (3), and nitromethane (4), form ideal solutions, calculate the bubble and dew pressure at 120 C of a mixture that contains equal moles of each of the four components. 

For a four-component ideal mixture at /Ci > > 3 > 4. the direct split... 

Let s examine a set of product points at F = 00 and its subset at F = 00 and N = 00 for a four-component ideal mixture (Fig. 3.4). Some point of the bottom product belonging to the possible bottom product region at set feed composition (dark shaded region to the right of point F) corresponds to the top product point... 

Figures 4.22a, b show two different flowsheets of autoextractive distillation of a four-component ideal mixture (K > K2 > K3 > K4). Both flowsheets ensure sharp separation in intermediate extractive section, because for any inner point of...

General regularities of the evolutions of sections trajectory bundles, discussed in the previous section for three-component mixtures, are valid also for the mixtures with bugger number of components. Figure 5.23 shows evolution of top section trajectory bundle at separation of four-component ideal mixture, when the product is pure component (i.e., at direct split) Ki > K2 > >... 

The case of a column with four ideal plates used to separate a mixture of ethyl alcohol and water may be considered. Initially there are Si moles of liquor of mole fraction xfl with respect to the more volatile component, alcohol, in the still. The top product is to contain a mole fraction xd, and this necessitates a reflux ratio R. If the distillation is to be continued until there are S2 moles in the still, of mole fraction xs2, then, for the same number of plates the reflux ratio will have been increased to R2. If the amount of product obtained is Db moles, then a material balance gives ... 

From an analytical standpoint, we would ideally prefer to maintain discrete solvent lines even upon introduction into the mass spectrometer. This would ensure that continued data integrity throughout the analytical process could be maintained and no there would be constraints on sample adjacencies. We embarked on a technical collaboration with Micromass (UK) to develop and construct an interface into a mass spectrometer that would achieve our goal. The result of this collaboration is the construction of a novel four-channel multiplex electrospray liquid chromatography interface that has been used to analyze single components and quaternary mixtures by LC-MS as well as synthetic samples prepared by automated procedures. 

Lithium tetraborate is not ideal for siliceous materials (categories (a), (b), (c), and much of (g) above), because it is too acidic for an acidic siliceous matrix. A near-eutectic mixture of one part by weight of lithium tetraborate to four of lithium metaborate used at a ratio of 5 1 (w/w) with the sample allows easy fusion of high-silica materials. The lower melting point also permits lower fusion temperatures, aiding the retention of volatile components such as sulfur, and reducible metal oxides such as PbO,... 

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