Distillation theory review

It must be borne in mind when reviewing the theories of the alchemists, that there were a number of phenomena known at the time, the superficial examination of which would naturally engender a belief that the transmutation of the metals was a common occurrence. For example, the deposition of copper on iron when immersed in a solution of a copper salt e.g., blue vitriol) was naturally concluded to be a transmutation of iron into copper, although, had the alchemists examined the residual liquid, they would have found that the two metals had merely exchanged places and the fact that white and yellow alloys of copper with arsenic and other substances could be produced, pointed to the possibility of transmuting copper into silver and gold. It was also known that if water (and this is tme of distilled water which does not contain solid matter in solution) was boiled for some time in a glass flask, some solid, earthy matter was produced and if water could be transmuted into earth, surely one metal could be... 

Today s petroleum distillation plants are compared with the units in existence in 1925, and a review is presented of the advances during the past 25 years in construction practices and materials, instrumentation, and engineering design, which have made possible the current technology. The theory and application of special processes, such as azeotropic and extractive distillation and Hypersorption, are discussed. The development of molecular distillation and rotary columns is described to indicate possible trends to be expected in the future. 

I wenty-five years of progress in the distillation of petroleum. That means going back to 1925, and some 32,245,073,000 barrels of petroleum have been produced in the United States since then substantially all of this production has been distilled—part of it several times. This paper reviews the development, of distillation processes, equipment, theory, and engineering during this period and suggests probable future innovations. 

Theoretical Efficiency Prediction Theoretical tray efficiency prediction is based on the two-film theory and the sequence of steps in Fig. 14-41. Almost all methods evolved from the AIChE model (AIChE Research Committee, Bubble Tray Design Manual, New York, 1958). This model was developed over 5 years in the late 1950s in three universities. Since then, several aspects of the AIChE model have been criticized, corrected, and modified. Reviews are given by Lockett (Distillation Tray Fundamentals, Cambridge University Press, Cambridge, England, 1986) and Chan and Fair [Ind. Eng. Chem. Proc. 

Edgar, T. F. and Schwanke, C. 0., "A Review of the Application of Modern Control Theory to Distillation Columns," Proc. Joint Automatic Control Conference, 1977, 1370. 

Literature pertaining to salt effect in vapor-liquid equilibrium and to extractive distillation using salt effect was recently reviewed by Furter and Cook (10), and the theory and technical aspects were reviewed by Furter (II). Vapor-liquid equilibrium data for 188 systems containing salt were previously compiled by Ciparis (12), who has also published a recent book with Dobroserdov and Kogan on the theory and practice of extractive distillation by salt effect (13). 

Before getting into specific applications of level control on distillation columns, let us review briefly the theory of averaging level control on simple vessels. 

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