Reactions in multiphase systems

For purposes of a quantitative discussion, let us first make the following assumptions A and B are binary compounds in a ternary system. The phases in the reaction product lie in the Gibbs triangle on the line joining A and B (see Fig. 6-2). 

In this way we have limited ourselves to a quasi-binary system. Unless interrupted externally, the reaction will continue until at least one of the two reactants is completely consumed (Gibbs phase rule). If the reaction is interrupted at a time when both reactants are still present, then the reaction product will consist of a sequence of all those phases which occur in the phase diagram as compounds between the reactants A and B in the quasi-binary system, as long as local equilibrium is maintained. It can be seen that we have here a convenient method for investigating quasi-binary lines in ternary phase diagrams. 

Suppose, for example, that two binary oxides react to form one or more ternary oxides as in Fig. 6-2. In order to properly understand the reaction, we must first be completely clear as to the number of independent thermodynamic variables. For a given total pressure and a given reaction temperature, there will still be one more independent variable in a binary system, and two more independent variables in a ternary system. Therefore, the experimental conditions are only completely defined if the activity of the component common to all compounds (i. e. the oxygen activity in this case) is fixed in the reaction zone. Only then are the local chemical potentials of the components and the transport coefficients (which depend, in general, upon these potentials) uniquely determined. 

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Burns, J. R., Ramshaw, C., The intensification of rapid reactions in multiphase systems using slug flow in capillaries. Lab. Chip 1 (2001) 10-15. 

Hofmann, H., 1983. in Mass Transfer with Chemical Reaction in Multiphase Systems, Vol. II Three-Phase Systems , Erdogan, A. (Ed.), Martinus Nijhoff Publishers, the Hague. 

Morsi, B. I., and Charpentier, J. C., On mass transfer with chemical reaction in multiphase systems. NATO ASI CESME, Izmir, Turkey, (1981). 

Metal NPs immobilized in ILs are highly active and recyclable for hydrogenation reactions in multiphase systems (see Scheme 1.2, Table 1.2, and Figure 1.5). 

Although we have indicated some applications of thermodynamics to biological systems, more extensive discussions are available [6]. The study of equilibrium involving multiple reactions in multiphase systems and the estimation of their thermodynamic properties are now easier as a result of the development of computers and appropriate algorithms [7]. 

The most catalytic or noncatalytic processes involving reactions in multiphase systems. Such processes include heat and mass transfer and other diffusion phenomena. The applications of these processes are diverse and its reactors have their own characteristics, which depends on the type of process. For example, the hydrogenation of vegetable oils is conducted in a liquid phase slurry bed reactor, where the catalyst is in suspension, the flow of gaseous hydrogen keeps the particles in suspension. This type of reaction occurs in the gas-liquid-solid interface. 

Mass transfer with chemical reaction in multiphase systems" covers, indeed, a large area. Table 1 shows a general classification of the systems encountered. From the possible two-phase systems, solid-solid reactions, liquid-solid (reactive or catalytic) and gas-solid (reactive or catalytic) reactions are not discussed here. The first one was reviewed by Tamhankar and Doraiswamy (2) and gas-solid (reactive) systems, such as, coal gasification, calcination of limestone, reduction of ores, etc. have been treated in some detail in recent reviews (3-5). The industrially important fluid-solid catalytic processes were the topic of a previous Advanced Study Institute (6) and have been also discussed authoritatively elsewhere (5,7). Concerning solid (reactive)-liquid two-phase systems, only some interesting examples are presented in Table 2 (1). 

Alper,E. "Introduction to liquid-liquid systems". (Proceedings of NATO ASI on "Mass transfer with chemical reaction in multiphase systems", Turkey., l98l). 

Deckwer, W.-D."Physical Transport Phenomena in Biological Tower Reactors"( Proceedings of NATO SI on "Mass transfer with chenical reaction in multiphase systems".Izmir,Turkey,1901)... 

Hofimann,H. "Reaction Engineering Problems in Slurry Reactors" (Proceedings of NATO ASI on "Mass Transfer with Chemical Reaction in Multiphase Systems", Izmir, Turkey, 1981). 

Mass Transfer with Chemical Reaction in Multiphase Systems... 

MASS TRANSFER WITH CHEMICAL REACTION IN MULTIPHASE SYSTEMS ... 

NATO Advanced Study Institute on Melss Transfer with Chemical Reaction in Multiphase Systems (I98I ... 

Hass transfer with chemical reaction in multiphase systems. 

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