Present Status of Our Approach to Reactor Sizing and Design

One final comment on the Arrhenius equation. Equation (3-181. It can be put in a most useful form by finding the specific reaction rate at a temperature To, that is, 

This equation says that if we know the specific reaction rale k T(,) at a temperature. 7q, and we know the activation energy, E. we can find the specific reaction rate k(T) at any other temperature, T, for tJiat reaction. 

4 Present Status of Our Approach to Reactor Sizing and Design 

In Chapter 2, we combined the different reactor mole balances with the definition of conversion to arrive at ihe design equation for each of four types of reactors, as shown in Table 3-2. Next we showed that if the rate of disappearance is known as a function of the conversion Jf  

In general, information in the form —rf = g X) is not available. However, we have seen in Section 3.2 that the rate of disappearance of A, — r, is normally expressed in terms of the concentration of the reacting species. This functionality. 

In Chapter 2. we showed how it was possible to size CSTRs, PFRs. and PBRs using the design equations in Table 3-2 (page 99) (/ the rate of disappearance of A is known as a function of conversion. X  

With these additional relationships, one observes that if the rate law is given and the concentrations can be expressed as a function of conversion, ilwn in fact tee have — as a ftmcrhn of X and this is all ihal is needed to ewiuaie ihe design ecjuatimis. One can u.se either the numerical techniques described in Chapter 2. or, as we shall see in Chapter 4, a table of integrals, and/or software programs (e.g.. Polymath). 

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Nonelementary Rate Laws and Reactions Present Status of Our Approach to Reactor Sizing and Design 83 Stoichiometric Table 84... 

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