Scaleup Relationships for Tubular Reactors

This chapter is restricted to homogeneous, single-phase reactions, but the restriction can sometimes be relaxed. The formation of a second phase as a consequence of an irreversible reaction will not affect the kinetics except for a possible density change. If the second phase is solid or liquid, the density change will be moderate. If the new phase is a gas, its formation can have a major effect. Specialized models are needed. Two-phase flows of air-water and steam-water in tubes have been extensively studied, but few data are available for chemically reactive systems. 

We begin a discussion of scaleup relationships and strategies for tubular reactors. Results are restricted to tubes with a constant cross-sectional area. Chapter 3 discusses only isothermal or adiabatic reactors, but the relationships in Tables 3.1-3.3 include scaleup factors for the nonisothermal reactors that are discussed in Chapter 5. These results assume constant density, but Tables 3.4 and 3.5 give some specialized results for ideal gases when the pressure drop down the tube is significant. 

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