An evaluation of models of mixing and chemical reaction with a turbulence analogy

Five mechanistic models of mixing and chemical reaction having an analogy with isotropic turbulent mixing are evaluated. The turbulence analogies, based on matching variance decay laws of models and turbulence theory, provide a physical basis for the models and a means of estimating their micromixing parameters apriori. Experimental data for single second order liquid phase reactions provide strong support for the analogies. However, it is demonstrated that in spite of their success for single reactions, the models may predict grossly different selectivities in the case of competing reactions in a plug flow reactor. This emphasizes the importance of certain structural features of the models which are independent of the existence of a turbulence analogy, such as: (i) reacting regions which are rich in each of the reactants of a two feedstream reactor, and (ii) unmixed regions in the reaction mixture. The importance of obtaining data for competing reactions in a highly segregated plug flow reactor for the p...

[1]  John R. Bourne,et al.  A FLUID MECHANICAL APPROACH TO TURBULENT MIXING AND CHEMICAL REACTION PART I INADEQUACIES OF AVAILABLE METHODS , 1984 .

[2]  J. Villermaux.  Mixing in Chemical Reactors , 1983 .

[3]  John M. Tarbell,et al.  Four environment model of mixing and chemical reaction. Part I. Model development , 1983 .

[4]  John M. Tarbell,et al.  Four environment model of mixing and chemical reaction. Part II. Comparison with experiments , 1983 .

[5]  B. W. Ritchie,et al.  A three-environment micromixing model for chemical reactors with arbitrary separate feedstreams , 1979 .

[6]  R. Brodkey,et al.  Turbulent motion, mixing, and kinetics in a chemical reactor configuration , 1975 .

[7]  B. Ritchie,et al.  Mixing and Product Distribution with Series-Parallel Reactions in Stirred Tank and Distributed Feed Reactors , 1975 .

[8]  Jacques Villermaux,et al.  Representation du melange imparfait de deux courants de reactifs dans un reacteur agite continu , 1975 .

[9]  A. Tobgy,et al.  Residence times, micromixing and conversion in an un-premixed feed reactor — II: Chemical reaction measurements , 1973 .

[10]  A. Tobgy,et al.  Residence times, micromixing and conversion in an un-premixed feed reactor—I. Residence time measurements , 1972 .

[11]  A. Tobgy,et al.  Monte Carlo methods of simulating micromixing in chemical reactors , 1972 .

[12]  O. Levenspiel.  Chemical Reaction Engineering , 1972 .

[13]  R. Adler,et al.  A conceptual framework for mixing in continuous chemical reactors , 1972 .

[14]  R. Shinnar,et al.  Scale‐up criteria for stirred tank reactors , 1969 .

[15]  R. E. Rosensweig.  Isotropic turbulent mixing with boundary sources , 1966 .

[16]  H. L. Toor,et al.  Second-order chemical reactions in a nonhomogeneous turbulent fluid , 1965 .

[17]  Octave Levenspiel,et al.  A Monte Carlo treatment for reacting and coalescing dispersed phase systems , 1965 .

[18]  S. Corrsin,et al.  The isotropic turbulent mixer: Part II. Arbitrary Schmidt number , 1964 .

[19]  R. Curl.  Dispersed phase mixing: I. Theory and effects in simple reactors , 1963 .

[20]  Th.N. Zwietering.  The degree of mixing in continuous flow systems , 1959 .

[21]  S. Corrsin.  Simple theory of an idealized turbulent mixer , 1957 .

[22]  P. V. Danckwerts.  The Definition and Measurement of Some Characteristics of Mixtures , 1952 .

[23]  J. Bourne,et al.  Mixing and fast chemical reaction—IV The dimensions of the reaction zone , 1982 .

[24]  Gary K. Patterson,et al.  APPLICATION OF TURBULENCE FUNDAMENTALS TO REACTOR MODELLING AND SCALEUP , 1981 .

[25]  John R. Bourne,et al.  Mixing and fast chemical reactionITest reactions to determine segregation , 1981 .

[26]  J. Ottino.  Lamellar mixing models for structured chemical reactions and their relationship to statistical models; Macro- and micromixing and the problem of averages , 1980 .

[27]  James C. Hill.  Models for Turbulent Transport Processes. , 1979 .

[28]  W. Ranz,et al.  A lamellar model for analysis of liquid-liquid mixing , 1979 .

[29]  B. Ritchie,et al.  GENERAL POPULATION BALANCE MODELLING OF UNPREMIXED FEEDSTREAM CHEMICAL REACTORS: A REVIEW , 1978 .

[30]  P. Costa,et al.  Reactions with non-linear kinetics in partially segregated fluids , 1972 .

[31]  H. L. Toor,et al.  A diffusion model for reactions with turbulent mixing , 1970 .

[32]  Daniel Yat Chiu Ng,et al.  The effect of incomplete mixing on conversion in homogeneous reactions , 1965 .

[33]  R. E. Rosensweig,et al.  Idealized theory for turbulent mixing in vessels , 1964 .