ABSTRACT
In Chapter 7, we introduced the basic steps that occur in a solid-catalyzed reaction. The three kinetic steps are detailed in Chapter 8. The remaining steps are those that involve the transport of mass and energy. As seen in Chapter 7, these steps can be divided into external transfer, which involves the transport of mass and energy through the external boundary layer that separates the bulk šuid from the solid, and internal transport, which occurs inside the catalyst volume if it is porous. The external transport is normally referred to as interphase transport, whereas that occurring within the catalyst is called intraphase transport. Both transport processes can lead to signi„cant changes in the observed rate, and, in extreme cases, may be the dominant rate-determining factors in the reactor. Reactors that are analyzed or designed without consideration of transport effects will in most cases fail to meet expectations.
