Partial Pressure Processes

Abstract

Partial pressure distillation", "stum distilbtion", and "azeotropic distillation" an t e r n used to repment the phenomenon of additive partial pressures due to the mutual immiscibility of many pain of liquids, as well as the methodc of carrying out separating operations and chemical reactions involving one or both of the liquids of the pair. The applications to industrial process are numerous, and tremendous tonnages of materials are separated or manufactured in many different industries by some of the methods described above, othen of the processes or operations described hwe been worked only on a small scale. 1106 swtmba, 1s41 I N D U S T R I A L A N D E N GAPORliquid equilibrium relations can be predicted V for only +ma of pairs of liqui-. e., thoae which sua p e r f d y immisdble and t h w which are perfectly raincible.In the hit oam the individual vapor pmsmrea of the respective matetiah am additive; in every other case more complicated reJations are involved. Thus, the compdtion of the vapm may be found from the law of additive vapor pressurea, which stgtee that the ratio of the molar percentages of the two constituene in the vapor is the same aa the ratio of the individual partial pressures at that temperature. Pok mbly a more convenient way of e x p m thie relation is to h t e that the hiling point of the mixture may be found by plotting the individual vapor pressures on the ordinata of merent temperatures, graphi~dy adding these pressures on these ordinaten, and debmining the intersection of the latter m e with the absciem repwenting the desired operating pmure. If, for example, 760 mm. is the pressure at whiah the b o i i temperatwe is desired, the intersection of the 760 nun. line with the additive curve wiU give the boiling temperature of a mixture of the liquids or the wcalled azstropic point. TaLing, for example, b e n e and water aa the insoluble liquids, the b o i i point of the first is 80.Zo and of the second, 100° C., and the hiling point or place at which the pressure of the combination rescbes 760 mm. is 89.26' C., with 8.83 per cent water and 91.17 per cent bemsene. Thus, the efiective boiling point of water has been reduced to 69.?Ba8" C. when in the presence of bemne. A deecription of a new method of plotting and calculating t h m relations waa recently pre m t e d (17). This addition of the pressures of immiscible liquids is tsken advantage of in industrial opemtions, often 8 p O h of 88 aseotropic distillation, partial pressure distillation, or steam distillation. h m DWiUdion practice of ehnl distillation wbich is used d y for loweringThe most cornmoll u~e of partial pressura distillstionis the the &&ve boiling point of one compound. In thin case the othw compormd is ahno& water, added as steam, and it wrvm to bringover ahigher boillng material at Bmne temperature below the boiling point of water.

Heterogeneous Catalysis and Solid Catalysts

“…Reactive Distillation [502][503][504] In reactive distillation (! Reactive Distillation) fractional distillation and chemical reaction are 1.…”

Catalytic Distillation

“…A detailed review on the subject was published as early as 1932 [2], and application was soon extended to other types of reaction, such as nitrations, sulfonations, and saponifications [3]. A detailed review on the subject was published as early as 1932 [2], and application was soon extended to other types of reaction, such as nitrations, sulfonations, and saponifications [3].…”

Heterogeneous Catalysis and Solid Catalysts

“…Reactive Distillation [526][527][528]. In reactive distillation (→ Reactive Distillation) fractional distillation and chemical reaction are performed simultaneously, e.g., for a reaction of the type A + B −→ C + D in which at least one of the products has a volatility which is different form those of the other compounds.…”