Dispersion second order reaction

FIG. 23-16 Concentration jump at the inlet of a closed ends vessel with dispersion. Second-order reaction with kCat = 5. 

FIG. 23-15 Chemical conversion by the dispersion model, (a) First-order reaction, volume relative to plug flow against residual concentration ratio, (h) Second-order reaction, residual concentration ratio against kC t. 

Determine the yield of a second-order reaction in an isothermal tubular reactor governed by the axial dispersion model with Pe = 16 and kt = 2. 

Solve the dispersion equation for a second order reaction for several... 

A second order reaction is to be conducted in a vessel whose RTD is an Erlang with n = 3. Find conversion with the dispersion and other models for... 

Apply the method of lines to the solution of the unsteady state dispersion reaction equation with closed end boundary conditions for which the partial differential equation for a second order reaction is,... 

Figure 17.5. Second-order reaction with dispersion identified by the Peclet number, Pe - uL/Dl.

P5.08.06. FIRST AND SECOND ORDER REACTIONS. TABLES AND GRAPHS The dispersion equation... 

With these two-point boundary conditions the dispersion equation, Eq. (23-50), may be integrated by the shooting method. Numerical solutions for first- and second-order reactions are plotted in Fig. 23-15. 

Fig. 5. Role of axial dispersion in the bed for single-phase and trickle flow. Minimum bed length as a function of conversion for first and second order reactions and for different catalyst sizes.

Direct contact heat transfer, 185 Dispersion model, 560-562 first order reactions, 561 second order reactions, 562 Distillation, 371-457 batch, 390 binary, 379 column assembly, 371 flash, 375... 

Ming-heng et al. (M15) employ a model for liquid-liquid dispersions similar to those mentioned previously. They analyzed droplet mixing on conversion for a second-order reaction occurring in the dispersed phase. The solution was obtained using the method of moment equations. 

The work discussed in this section clearly delineates the role of droplet size distribution and coalescence and breakage phenomena in mass transfer with reaction. The population balance equations are shown to be applicable to these problems. However, as the models attempt to be more inclusive, meaningful solutions through these formulations become more elusive. For example, no work exists employing the population balance equations which accounts for the simultaneous affects of coalescence and breakage and size distribution on solute depletion in the dispersed phase when mass transfer accompanied by second-order reaction occurs in a continuous-flow vessel. Nevertheless, the population balance equation approach provides a rational framework to permit analysis of the importance of these individual phenomena. 

The utility of the model to predict the effects of interdroplet mixing on extent of reaction was demonstrated for the case of a solute diffusing from the dispersed phase and undergoing second-order reaction in the continuous phase. For this comparison the normalized volumetric dispersed-phase concentration distribution is deflned as fv(y) dy equal to the fraction of the total volume of the dispersed phase with dimensionless concentration in the range y to y -i- dy, where y = c/cq and... 

Fig. 17. Comparison of volumetric dispersed-phase concentration distribution for various levels of droplet mixing for second-order reaction in the continuous phase, = 0.006 [after Zeitlin and Tavlarides (Z3)].

Flocculation and Coalescence. Flocculation being the primary process, the droplets of the dispersed phase come together to form aggregates. In this process, the droplets have not entirely lost their identity and the process can be reversible. Since the droplets are surrounded by the double layer, they experience the repulsive effect of the double layer. Kinetically, flocculation is a second order reaction since it depends in the first instance on the collision of two droplets and is expressed in the form (31)... 

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