Hydrodynamic homogeneous chemical kinetics

In order to be able to represent the behaviour of fluidized bed reactors with confidence, one must have a thorough understanding of the bed hydrodynamics and of the reaction kinetics. Almost all of the reactions carried out in fluidized beds are either solid-catalysed gas phase reactions or gas-solid reactions. (We will not consider here homogeneous gas phase reactions, reactions in liquid fluidized beds or reactions in three phase fluidized beds.) While the chemical kinetics can often be highly complex. 

Let us first consider briefly how the use of mass transport as a variable can provide a guide to the reaction mechanism and give quantitative kinetic detail. As an illustration, we consider the behaviour of CE and EC processes (where E signifies electron transfer and C represents a chemical step) at a rotating disc electrode (RDE). This hydrodynamic system has already been discussed by Albery et al. and the reader is referred to Chap. 4 for details. CE and EC processes represent the simplest conceivable electrode reactions involving coupled homogeneous kinetics mechanistic examples of both types are shown in Table 1. In the discussion which follows, the electron-transfer reaction in the two mechanisms is considered to be a cathodic process the extension to the anodic case is trivial. 

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