Simultaneous Mass and Energy Transfer

Figure 11.2. Film model for simultaneous mass and energy transfer. 

Since the heat capacity of SO3 is very high there is a substantial correction to the heat transfer coefficient caused by simultaneous mass transfer. Simultaneous mass and energy transfer needs to be properly taken into consideration in the design of industrial thin-film sulfonation reactors. ... 

Typical composition and temperature profiles in condensation operations are shown in Figure 15.4. The analysis of mass and energy transfer in condensation that follows is an extension of the general analysis of simultaneous mass and energy transfer presented in Section 11.5. The additional complication here is that we must account for energy transfer (but not mass transfer) across the tube wall into the coolant. 

Develop the film model for simultaneous mass and energy transfer including Soret and Dufour effects. Use the Toor-Stewart-Prober linearized theory in developing the model. An example of a process where thermal diffusion effects cannot be ignored is chemical vapor deposition. Use the model to perform some sample calculations for a system of practical interest. You will have to search the literature to find practical systems. To get an idea of the numerical values of the transport coefficients consult the book by Rosner (1986). 

In the five chapters that make up Part II (Chapters 7-11) we consider the estimation of rates of mass and energy transport in multicomponent systems. Multicomponent mass transfer coefficients are defined in Chapter 1, Chapter 8 develops the multicomponent film model, Chapter 9 describes unsteady-state diffusion models, and Chapter 10 considers models based on turbulent eddy diffusion. Chapter 11 shows how the additional complication of simultaneous mass and energy transfer may be handled. 

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