On the Use of More Complex Kinetic Equations

Derive (4.2-6) by using simple geometric arguments (see also Kim and Smith [1974] and Wen [1968]). 

Consider the general model with the reaction first order in fluid-phase concentration  

note that the results of Chapter 3 can be utilized to solve the transformed problem. 

For a zero-order solid concentration dependence (/(C5) = C50), show that the following results are obtained  

4 The secondary steam reformer of an ammonia plant has to be opened to replace the Ni/alumina catalyst. This requires the prior careful reoxidation of the pyrophoric Ni-catalyst. Simulate the reoxidation by means of an oxygen/nitrogen mixture containing 5 volume % oj gen. Use the general model of Section 4.2 to calculate the evolution with time of the concentration profiles of oxygen ( ) and Ni (. in the catalyst particle for various values of the rate parameters and for conversions based on 5 of up to 50 %. The initial Ni content of the catalyst (Cso) is 0.00624 kmoFkg cat. 

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