Nonequilibrium stage model

Powers MF, Vickery DJ, Arehole A, Taylor R. A nonequilibrium-stage model of multicomponent separation processes—V. Computational methods for solving the model equations. Computers Chem Eng 1988 12 1229-1241. 

Two different approaches have evolved for the simulation and design of multicomponent distillation columns. The conventional approach is through the use of an equilibrium stage model together with methods for estimating the tray efficiency. This approach is discussed in Chapter 13. An alternative approach based on direct use of matrix models of multicomponent mass transfer is developed in Chapter 14. This nonequilibrium stage model is also applicable, with only minor modification, to gas absorption and liquid-liquid extraction and to operations in trayed or packed columns. 

In the nonequilibrium stage model of Krishnamurthy and Taylor (1985a) the total mass transfer rates are obtained by combining Eqs. 11.5.3a and lL5.5a and multiplying by the interfacial area available for mass transfer... 

In Section 13.5.1 we presented the data of Vogelpohl for the distillation of two ternary systems acetone-methanol-water and methanol-2-propanol-water in a bubble cap column. Krishnamurthy and Taylor (1985b) simulated these experiments using a nonequilibrium stage model similar to the one described above. The AIChE correlations were used to calculate the mass transfer coefficients. Thermodynamic properties were calculated with the models described by Prausnitz et al. (1980). 

Krishnamurthy, R. and Andrecovich, M. J., Application of a Nonequilibrium Stage Model to Cryogenic Process Simulation, Proceedings of the International Symposium on Gas Separation Technology, held in Antwerp, Belgium, Vansant, E. F. and Dewolfs, R. (Eds.), Elsevier, Amsterdam, The Netherlands, 1989. 

Krishnamurthy, R. and Taylor, R., A Nonequilibrium Stage Model of Multicomponent Separation Processes. I—Model Development and Method of Solution, AIChE J, 31, 449-456 (1985a). 

Zimmermann, A., Gourdon, C., Joulia, X., Gorak, A., and Casamatta, G., Simulation of Multicomponent Extraction Process by a Nonequilibrium Stage Model Incorporating a Drop Population Model, Comput. Chem. Eng., 16 (Suppl.), S403-S410 (1992). 

Chapter 12 presents models of mass transfer on distillation trays. This material is used to develop procedures for the estimation of point and tray efficiencies in multicomponent distillation in Chapter 13. Chapter 14 uses the material of Chapter 12 in quite a different way in an alternative approach to the simulation and design of distillation and absorption columns that has been termed the nonequilibrium stage model. This model is applicable to liquid-liquid extraction with very little modification. Chapter 15 considers the design of mixed vapor condensers. 

Baur R., Higler A., Taylor R. and Krishna R. (2000). Comparison of equilibrium stage and nonequilibrium stage models for reactive distillation. Chemical Engineering Journal 76, 33-47. 2.1, 2.6, 2.9.3,... 

Krishnamurthy R. and Taylor R. (1985). Nonequilibrium stage model of multicomponent separation... 

Wolf-Maciel M.R., Soares C. and Barros A.A.C. (2001). Validations of the nonequilibrium stage model and of a new efficiency correlation for non ideal distillation process through simulated and experimental data. Computer-Aided Chemical Engineering 9, 321-326. 2.9.3... 

Yu S., Zhou A. and Tan Q. (1997). Simulation of multistage catalytic stripping with a nonequilibrium stage model. Computers and Chemical Engineering 21 (4), 409-415. 2.9.3... 

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