2-Butanone azeotropes

Methyl-2-butanone was purchased from Eastman Chemical Products, Inc. and distilled prior to use. It appeared that water was azeotropically removed during the distillation, and thus a significant fore run was discarded. 

AWticih (Aldrich also supplies l-diethylamino-3-butanone). Methyl vinyl ketone is made commercially by hydration of vinylacetylene. The du Pont material, an azeotrope containing 85% methyl vinyl ketone and 15% water, can be dried by treat- me t with excess anhydrous potassium carbonate the organic layer is separated, chilled in ice, dried first over calcium chloride and then potassium carbonate, and distilled b.p. 30-32°/120 mm., or 35-36°/140 mm. Material from Matheson, Coleman and Bell can be used as received. 

At 120°C, both components in this binary indicate positive deviation in one composition range and negative deviation in another (Figure 1.13). The system also indicates a slight maximum pressure azeotrope near a water mole fraction of 0.95 (Figures 1.13 and 1.15). Additionally, a maximum is observed for the activity coefficient of water (Figure 1.14, curve 1) and a minimum for the activity coefficient of 3-hydroxy-2-butanone (curve 2). These phenomena are best represented by the Margules equation. 

Ethyl methyl ketone (2-butanone) is purified in the same ways as for acetone, but it should be noted that it yields an azeotrope containing 11.3% of water. 

The binary mixture water (1) / butanone (2) exhibits an interesting phase behaviour the azeotrope lies outside the immiscibility region. Study the ability of a liquid activity model to describe accurately both VLE and LLE. 

LCSTs can also exhibit VLLE examples include water -i- 2-butanol and water -t 2-butanone. In such cases, VLLE prevents formation of a closed solubility loop, (ii) Many immiscible liquids form homogeneous azeotropes at high pressures, as in Figure 9.15, but some do not. Those without azeotropes include CO2 + long-chain alkanes, such as n-octane and n-decane. (iii) Often VLLE occurs at heterogeneous azeotropes, as in Figure 9.15, and then the vapor-phase composition lies between the compositions of the two liquid phases. However, VLLE also occurs in some mixtures in which the vapor-phase composition does not lie between the compositions of the liquid phases. Examples of the latter include ammonia + toluene and water + phenol. 

Briefly explain why removing water by azeotropic distillation with benzene drives the reaction of 2-butanone and excess ethanol to product when done in benzene as a solvent with an acid catalyst. 

Butanone-water azeotrope Diethyl ether-toluene Benzene-diethyl ether Ethyl acetate Diethyl ether-petrol ether (B. P. 60--80° C)... 

Trimethylamine, azeotrope compo sition independent of pressure Thiophene Crotonaldehyde 2-Butanone Dioxane... 

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