Plate catalyst pellets

Develop expressions for the Thiele modulus and the concentration profile of A for the following reversible first-order reaction that takes place in a flat plate catalyst pellet ... 

Set up the equations necessary to calculate the effectiveness factor for a flat-plate catalyst pellet in which the following isothermal reaction takes place ... 

The porosity (i ) and tortuosity (t ) of the flat plate catalyst pellet are then used to calculate the ejfective diffusivities associated with each component according to ... 

To evaluate the effectiveness factor for a first-order, isobaric, nonisothermal, flat plate catalyst pellet, the material and energy balances must be solved simultaneously. As shown previously, the mole balance in a slab is given by ... 

Consider a first-order reaction occurring on a nonporous flat plate catalyst pellet. In Section 6.2, it was shown that the concentration of reactant A on the external surface of the catalyst is related to both the mass transfer coefficient, k, and the surface rate constant, ks. ... 

Now consider the first-order reaction in a porous flat plate catalyst pellet so that both external (interphase) and internal (intraphase) transport limitations are encountered. At steady state, the flux of A to the surface of the pellet is equal to the flux entering the pellet ... 

For example, an isothermal, first-order reaction in a flat plate catalyst pellet has individual effectiveness factors that are ... 

The isothermal, reversible, first-order reaction A = B occurs in a flat plate catalyst pellet. Plot the dimensionless concentration of A (Ca/C s) as a function of distance into the pellet for various values of the Thiele modulus and the equilibrium constant. To simplify the solution, let Cas = 0.9(Ca + Cg) for all cases. 

Fig. 11-8 Reactor for a single flat-plate catalyst pellet...

We consider the situation depicted in Figure 4.5, involving transport through a gas film to a liquid interface, followed by diffusion and reaction in the liquid film. The difference element over which the mass balance is taken is the same as that for the flat-plate catalyst pellet, and leads to the same differential equation and the same boxmdary conditions ... 

Derive the energy balance for a flat-plate catalyst pellet operating under nonisothermal conditions (first-order exothermic reaction). Give a plausible argument why the effectiveness factor can in this case exceed unity. 

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