Liquids distillation

Place 45 g. of benzamide (Section IV, 188) and 80 g. of phosphorus pentoxide in a 250 ml. Claisen flask (for exact experimeutal details on the handling and weighing out of phosphoric oxide, see under Acetamide, Section 111,111). Mix well. Arrange for distillation (Fig.//, 29, 1 or Fig. II, 20, 1) under reduced pressure use a water pump with an air leak in the system so that a pressure of about 100 mm. is attained. Heat the flask with a free flame until no more liquid distils the nitrile will pass over at 126-130°/100 mm. Wash the distillate with a little sodium carbonate solution, then with water, and dry over anhydrous calcium chloride or magnesium sulphate. Distil under normal pressure (Fig. II, 13, 2 or II, 13, 6) from a 50 ml. flask the benzonitrile passes over as a colourless liquid at 188-189° (compare Section IV,66). The yield is 28 g. 

Steam distillation. When two immmiscible liquids distil, the sum of their (independent) partial pressures is equal to the atmospheric pressure. Hence in steam distillation, the distillate has the composition... 

Fractional Distillation.—It is often possible to separate almost completely by a single distillation, two liquids occurring together in a mi.xture when their boiling points he widely apart. The more volatile liquid first passes over, the temperature suddenly iise and the higher boiling liquid distils. 

The product of condensation remaining in the distilling apparatus is purified by the fractional distillation in vacuo. Under a pressure of 12 mm. a liquid distils off at a temperature of from 143° to 145° C. This product of condensation which I term Pseudo-ionone, is a ketone readily decomposable by the action of alkalis. Its... 

The reaction mixture was removed from the vessel and distilled at a pressure of 30-60 mm, and a bath temperature of 30°C to 50°C until the methanol had all been removed. The extremely viscous tarry residue remaining in the still pot was given a very crude distillation, the distillate boiling at B2°C to 1 32°C/2 mm. In an attempt to purify this distillate by a more careful distillation, 5.3 g of a liquid distilling from 53°C to 150°C/5 mm was collected. At this point, much solid sublimate was noted not only in this distillate but in the condenser of the still. 7 g of the solid sublimate was scraped out of the condenser of the still. Recrystallization of the sublimate from ethyl acetate containing a small amount of petroleum ether gave beautiful crystals melting at 175°C to 177°C (5 g). Infrared analysis confirmed that this compound was hydroquinone (9% conversion). 

For example, for steam (saturated vapor, no liquid) distillation with one organic compound (liquid), there are two phases, two components, and two degrees of freedom. These degrees of freedom that can be set for the system could be (1) temperature and (2) pressure or (1) temperature and/or (2) concentration of the s) stem components, or either (1) pressure and (2) concentration. In steam distillation steam may be developed from water present, so there would be both a liquid water and a vapor phase water (steam) present. For such a case, the degrees of freedom are F = 2 + 2- 3 = l. 

Table 15.4 shows typical applications for the range of oil fuels for use with major prime movers. Medium/high-speed diesel engines generally use distillate fuel oils while medium/low-speed units generally bum residual fuels. The gas turbine, which normally operates on liquid distillate fuels, is capable of running on residual fuels, although examples of these are normally associated with crude production facilities. 

The breaking up of azeotropic mixtures Steam distillation. Distillation of a pair of immiscible liquids Distillation with superheated steam. ... 

C. 3-Methylcoumarone. Dry 3-methylcoumarilic acid (50 g.) is distilled from a 250-ml. Claisen flask fitted with a long air condenser and immersed in a Wood s metal bath heated slowly to 280°. Carbon dioxide is evolved, and a cloudy liquid distils at 190-220°. The crude product is purified by redistillation through a Vigreux column (Note 6). The dear colorless distillate, weighing 31.5-33 g. (84-88%), boils at 195-197°, n 1.5520. 

The arrangement illustrated in Fig. 23 permits of the continuous distillation in a vacuum of large amounts of liquid, in particular water. By operating the cock from time to time the liquid distilled can be replaced by suction from the storage vessel. 

Volumetric liquid holdups in the reflux drum and column base are held perfectly constant by changing the flow rates of bottoms product B and liquid distillate product. ... 

Vapor and liquid distillate product flow rates (lb - mol/h)... 

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