Reactor Choice for Gas-Liquid Reactions

As must be evident from a previous section on classification, gas-liquid reactions can be carried out in a large number of reactor types. This is also true of other multiphase reactions in which a liquid phase is involved. For other reactions such as gas-solid, catalytic or noncatalytic, the choice of reactor is confined to a lesser number of variations. Therefore, although reactor choice is an important consideration for all reactions, particularly heterogeneous reactions, it is more so for gas-liquid, liquid-liquid, and slurry systems, all of which are widely used in industrial organic synthesis. We discuss below the cost minimization criteria for a rational choice of reactors for gas-liquid reactions. 

Any criterion for volume minimization must be based on the extent to which reaction occurs in the film. The criterion for a reaction to occur entirely in the film is given by the inequality 

A more elaborate criterion (Kastanek et al., 1993) can also be used based on a parameter N defined as 

The magnitude of N provides a valuable guideline for reactor selection. Table 16.4 presents a broad indication of the types of contactors recommended for 

Criterion based on value of N Regime Type of reactor 

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