In chemical engineering

The most commonly used index is the chemical engineering plant cost index published in Chemical Engineering Magazine. 

The use of group contribution methods for the estimation of properties of pure gases and Uquids [20, 21] and of phase equilibria [22] also has a long history in chemical engineering. 

Additivity schemes for estimating molecular properties play an important role in chemical engineering. 

Separation Efficiency. Similarly to other unit operations in chemical engineering, filtration is never complete. Some soflds may leave in the hquid stream, and some Hquid will be entrained with the separated soHds. As emphasis on the separation efficiency of soHds or Hquid varies with application, the two are usually measured separately. Separation of solids is measured by total or fractional recovery, ie, how much of the incoming solids is coUected by the filter. Separation of Hquid usually is measured in how much of it has been left in the filtration cake for a surface filter, ie, moisture content, or in the concentrated slurry for a filter-thickener, ie, solids concentration. 

T. Umeda, T. Harada, and K. Shiroko, "A Thermodynamic Approach to the Synthesis of Heat Integration Systems in Chemical Processes," Proceedings of the 12th Symposium on Computer Applications in Chemical Engineering, Montreaux, Swit2edand, 1979, p. 487. 

D. M. Himmelblau, Basic Principles and Calculations in Chemical Engineering, Prentice Hall, Inc., Englewood Cliffs, N.J., 1962. 

T. D. Farr, Phosphorus, Properties of the Element and Some of Its Compounds, in Chemical Engineering Report, No. 8, Tennessee Valley Authority, Wilson Dam, Ala., 1950, pp. 39 and 58. 

V. E. Jenson and G. V. Jeffreys, Mathematical Methods in Chemical Engineering, Academic Press, Inc., Orlando, Ela., 1990. 

National Research Council, Frontiers in Chemical Engineering. Kesearch Needs and Opportunities, National Academy Press, Washington, D.C., 1988, Chapt. 3. 

Ordinary diffusion involves molecular mixing caused by the random motion of molecules. It is much more pronounced in gases and Hquids than in soHds. The effects of diffusion in fluids are also greatly affected by convection or turbulence. These phenomena are involved in mass-transfer processes, and therefore in separation processes (see Mass transfer Separation systems synthesis). In chemical engineering, the term diffusional unit operations normally refers to the separation processes in which mass is transferred from one phase to another, often across a fluid interface, and in which diffusion is considered to be the rate-controlling mechanism. Thus, the standard unit operations such as distillation (qv), drying (qv), and the sorption processes, as well as the less conventional separation processes, are usually classified under this heading (see Absorption Adsorption Adsorption, gas separation Adsorption, liquid separation). 

S. M. Walas, Phase Equilibria in Chemical Engineering, Butterworths, Reading, Mass., 1985. 

Marshall Swift, pubHshed monthly in Chemical Engineering. 

Scale- Up of Electrochemical Reactors. The intermediate scale of the pilot plant is frequendy used in the scale-up of an electrochemical reactor or process to full scale. Dimensional analysis (qv) has been used in chemical engineering scale-up to simplify and generalize a multivariant system, and may be appHed to electrochemical systems, but has shown limitations. It is best used in conjunction with mathematical models. Scale-up often involves seeking a few critical parameters. Eor electrochemical cells, these parameters are generally current distribution and cell resistance. The characteristics of electrolytic process scale-up have been described (63—65). 

James O. Maloney is Professor Emeritus of the Department of Chemical and Petroleum Engineering, University of Kansas. He holds a Ph.D. degree in chemical engineering from Pennsylvania State University. In 1941 he began liis professional career at the DuPont de Nemours Company, before joining the University of Kansas in 1945, where he taught for 40 years. He served as department chairman for nineteen years. He is a fellow of the AIChE. 

In chemical engineering, the primary application of the diffusivity is to calculate the Schmidt number ( l/pD) used to correlate mass transfer properties. This number is also used in reaction rate calculations involving transport to and away from catalyst surfaces. 

Finlayson, B. A. Nonlinear Analysis in Chemical Engineering. McGraw-Hill, New York (1980). 

Hanna, O. T, and O. C. SandaU. Computational Methods in Chemical Engineering, Prentice Hall, Upper Saddle River, NJ (1994). 

Walas, S. M. Modeling with Differential Equations in Chemical Engineering. Butterworth-Heinemann, Stoneham, MA(1991). 

Conduction with Change of Phase A special type of transient problem (the Stefan problem) involves conduction of heat in a material when freezing or melting occurs. The liquid-solid interface moves with time, and in addition to conduction, latent heat is either generated or absorbed at the interface. Various problems of this type are discussed by Bankoff [in Drew et al. (eds.). Advances in Chemical Engineering, vol. 5, Academic, New York, 1964]. 

Reported by Westwater in Drew and Hoopes, Advances in Chemical Engineering, vol. I, Academic, New York, 1956, p. 15. 

Calculations of Giierrieri (S.M. thesis in chemical engineering, MIT, 1932) from room-temperature absorption measurements of Cohlentz (Investigations of Infrared Spectra, Carnegie Institution, Washington, 1905) with poor allowance for temperature. 

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