Acetone, binary azeotropes with

Isoprene [78-79-5] (2-methyl-1,3-butadiene) is a colorless, volatile Hquid that is soluble in most hydrocarbons but is practically insoluble in water. Isoprene forms binary azeotropes with water, methanol, methylamine, acetonitrile, methyl formate, bromoethane, ethyl alcohol, methyl sulfide, acetone, propylene oxide, ethyl formate, isopropyl nitrate, methyla1 (dimethoxymethane), ethyl ether, and / -pentane. Ternary azeotropes form with water—acetone, water—acetonitrile, and methyl formate—ethyl bromide (8). Typical properties of isoprene are Hsted in Table 1. 

The quantity of hexane necessary to entrain water, methanol, ethanol, acetone, and acetaldehyde dimethyl acetal to the top was estimated as the sum of the hexane quantities required to form the binary azeotropes with the quantities of water, methanol, ethanol, acetone, and acetaldehyde dimethyl acetal in the mixture. 

Liquid with pungent odor. bp7 81.4. tig 1.4086. dj 0.8636 dj5 0 8407. Easily soluble in water, methanol, ethanol, ether, acetone, glacial acetic acid. Slightly sol in hydrocarbons. Forms a binary azeotrope with water, bp 75 (12% water), uv spectrum and electric moments Rogers, J. Am. Chem. Soc. 69, 2544 (1947). Polymerizes on standing, LDm in mioe and rats 35 mg/kg, C.A. 72, 124809b 0970). 

Schematic DRD shown in Fig. 13-59 are particularly useful in determining the imphcations of possibly unknown ternary saddle azeotropes by postulating position 7 at interior positions in the temperature profile. It should also be noted that some combinations of binary azeotropes require the existence of a ternaiy saddle azeotrope. As an example, consider the system acetone (56.4°C), chloroform (61.2°C), and methanol (64.7°C). Methanol forms minimum-boiling azeotropes with both acetone (54.6°C) and chloroform (53.5°C), and acetone-chloroform forms a maximum-boiling azeotrope (64.5°C). Experimentally there are no data for maximum or minimum-boiling ternaiy azeotropes. The temperature profile for this system is 461325, which from Table 13-16 is consistent with DRD 040 and DRD 042. However, Table 13-16 also indicates that the pure component and binary azeotrope data are consistent with three temperature profiles involving a ternaiy saddle azeotrope, namely 4671325, 4617325, and 4613725. All three of these temperature profiles correspond to DRD 107. Experimental residue cui ve trajectories for the acetone-...

Based on the above information, the CAMD problem definition is revised as follows - The solvent can be acyclic hydrocarbons and ketones (aromatic compounds, chlorides, dioxanes are not considered for EH S concerns). The normal boiling point should be higher than that of chloroform (334 K), the molecular weight could be between 70-120, the solvent must not form azeotrope with either acetone or chloroform, and, must be totally miscible with the binary mixture of acetone and chloroform. 

Figure 3.10 shows typical RCM for nonideal mixtures involving azeotropes. For the mixture ace tone/heptane /benzene (plot a) there is only one distillation field. The problem seems similar to a zeotropic system, except for the fact that the minimum boiler is a binary azeotrope and not a pure component. With the mixture acetone/chloroform/toluene (plot b) there is one distillation boundary linking the high-boiler with the low-boiler azeotrope. Consequently, there are two distillation regions. Similar behavior shows the plot c, with two azeotropes. The mixture acetone/chloroform/methanol (plotd) has four azeotropes (3 binaries and 1 ternary) displaying a behavior with four distillation regions. 

Figure 9.4 displays RCMs for some typical azeotropic mixtures. Figure 9.4a presents the mixture acetone (56.2 °C) / benzene (80.1 °C) / heptane (98.4 °C). Acetone and heptane form a minimum boiling azeotrope with nbp of 55.1 °C, which is the lowest boiler. It may be observed that the residue curves emanate from the azeotropic point, take the direction to the benzene/heptane edge, and then deflect to the heptane vertex. Binary azeotrope and heptane are unstable and stable nodes, respectively. Acetone and benzene are saddles. In this case there is a single distillation region, as for zeotropic mixtures, but the shape of the residue curves is peculiar. 

Finally, Figure 9.4d illustrates a more complex situation, the mixture acetone/ chloroform/methanol, with four azeotropes (three binaries and one ternary). There are four distillation regions. Note that the ternary azeotrope is a saddle. 

Fig. 231 shows the equilibrium curves of the azeotropic nii.xture acetone-chloroform to which have been added various amounts of the extracting agent, ineth>l-isobntylketone. (The quantities are mole fractions.) The binary S3 stem gives an azeotrope with maximum boiling point at 34.5 mol%. This disappears when 30 mol , of the additive is present further additions cau.se a still larger increase in the relative volatility [50]. 

The binary azeotrope between acetone and methanol is the point with the lowest temperature on the map, and all profiles originate from this point. 

Let s illustrate the location of trajectory bundles of reversible distillation by the example of three-component acetone(l)-benzene(2)-chloroform(3) mixture with one binary saddle azeotrope with a maximum boiling temperature (Fig. 4.7)... 

The diagrams of reversible distillation were constructed for some types of three-component azeotropic mixtures. It is interesting that some types of mixtures with one binary azeotrope and with two distillation regions [types 3 and 5 according to classification (Gurikov, 1958)] permit sharp separation into component and binary zeotropic mixture at some feed compositions. The mixture acetone(l)-benzene(2)-chloroform(3) is an example of such mixture. 

The apphcation of extractive distillation is of great practical importance because it ensures the possibility of sharp separation of some types of azeotropic mixtures into zeotropic products, which is impossible in a colunm with one feeding. The mixture acetone(l)-water(2)-methanol(3) is an example of this type of mixture. Trajectories of reversible distillation of three sections of extractive distillation column, the feeding of which is binary azeotrope acetone-methanol, the extractive... 

We examine separation of the mixtures, concentration space of which contains region of existence of two hquid phases and points of heteroazeotropes. It is considerably easier to separate such mixtures into pure components because one can use for separation the combination of distillation columns and decanters (i.e., heteroazeotropic and heteroextractive complexes). Such complexes are widely used now for separation of binary azeotropic mixtures (e.g., of ethanol and water) and of mixtures that form a tangential azeotrope (e.g., acetic acid and water), adding an entrainer that forms two liquid phases with one or both components of the separated azeotropic mixture. In a number of cases, the initial mixture itself contains a component that forms two liquid phases with one or several components of this mixture. Such a component is an autoentrainer, and it is the easiest to separate the mixture under consideration with the help of heteroazeotropic or heteroextractive complex. The example can be the mixture of acetone, butanol, and water, where butanol is autoentrainer. First, heteroazeotropic distillation of the mixture of ethanol and water with the help of benzene as an entrainer was offered in the work (Young, 1902) in the form of a periodical process and then in the form of a continuous process in the work (Kubierschky, 1915). 

We now discuss a more complicated task separation of five-component mixture water(l)-methanol(2)-acetic acid(3)-acetone(4)-pyridin(5) with three binary azeotropes 15, 24, 35 (Petlyuk et al., 1985). Figure 8.12 shows seg-... 

For the second example, separation of mixture water(l)-methanol(2)-acetic acid(3)-aceton(4)-pyridin(5), both possible splits in first column with one feeding without distributed component 2,4 1,3,5 and 1,2,4 3,5, are not expedient because one of the products is binary mixture with azeotrope. 

Knapp and Doherty studied heat-integration of binary homogeneous azeotropic systems using extractive distillation methods. One of their examples considered the acetone-methanol system with water as the solvent. They did not consider pressure-swing distillation, nor did they consider dynamics and control. 

The acetone-methanol binary homogeneous minimum-boiling azeotropic system is considered with some of the solvents studied by Kossack et al. Three solvents are explored that have different normal boiling points (373 K for water, 464 K for DMSO, and 405 K for chlorobenzene). These solvents have different effects on the azeotropic mixture. The first and second solvents drive the acetone overhead in the extractive column. The chlorobenzene solvent drives the methanol overhead in the extractive column. The normal boiling points of acetone and methanol are 329 and 338 K, respectively, so acetone is the lighter component and would preferentially go overhead. The composition of the acetone-methanol azeotrope is 77.6 mol% acetone at atmospheric pressure as shown in Figure 11.1. 

Such a process depends upon the difference in departure from ideally between the solvent and the components of the binary mixture to be separated. In the example given, both toluene and isooctane separately form nonideal liquid solutions with phenol, but the extent of the nonideality with isooctane is greater than that with toluene. When all three substances are present, therefore, the toluene and isooctane themselves behave as a nonideal mixture and then-relative volatility becomes high. Considerations of this sort form the basis for the choice of an extractive-distillation solvent. If, for example, a mixture of acetone (bp = 56.4 C) and methanol (bp = 64.7°Q, which form a binary azeotrope, were to be separated by extractive distillation, a suitable solvent could probably be chosen from the group of aliphatic alcohols. Butanol (bp = 117.8 Q, since it is a member of the same homologous series but not far removed, forms substantially ideal solutions with methanol, which are themselves readily separated. It will form solutions of positive deviation from ideality with acetone, however, and the acetone-methanol vapor-liquid equilibria will therefore be substantially altered in ternary mixtures. If butanol forms no azeotrope with acetone, and if it alters the vapor-liquid equilibrium of acetone-methanol sufficiently to destroy the azeotrope in this system, it will serve as an extractive-distillation solvent. When both substances of the binary mixture to be separated are themselves chemically very similar, a solvent of an entirely different chemical nature will be necessary. Acetone and furfural, for example, are useful as extractive-distillation solvents for separating the hydrocarbons butene-2 and a-butane. 

A feed stream at the rate of 100 kmol/h contains 50% mole acetone and 50% mole chloroform. The two components form a maximum boiling azeotrope which prevents their separation by conventional distillation. It is proposed to separate them by extractive distillation using benzene as a solvent, at a rate of 800 kmol/h. Both the main feed and the solvent are at 75 C and 110 kPa, and the column pressure is assumed uniform, also at 110 kPa. A total condenser is used, with a reflux ratio of 4. The distillate composition is specified at 95% mole acetone and the bottoms at 5% mole acetone on a solvent-free basis. Using the pseudo-binary... 

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