Figure 17.12 Final design for type IIR process (LLK + LK , HK + HHK).
8S. P. Chopade and M. M. Sharma, Reaction of ethanol and formaldehyde: Use of versatile cation-exchange resins as catalyst in batch reactors and reactive distillation columns, Reactive and Functional Polymers. 32, 53-64 (1997).
expected, the LK (component D) is introduced into the condenser, and the LLK (component C) is fed into the reactive zone that is 9 trays below (Fig. 17.12). The reflux/feeds ratio is around 4, and the boilup ratio is also close to 4. These values are much higher than that of type IIp, which lead to higher energy consumption in the reactive distillation column.
This example illustrates the conflict between reactant concentration and reaction temperature for a chemical reaction, and this is a particularly important feature of reactive distillation. Because of the reversible reaction, the reactive zone should be placed where the reactants are most abundant. In the type IIp example considered in this section, this occurs in the upper section of the reactive distillation column, which is the low temperature zone. It is interesting to note that the reaction temperature is the lowest (reflux drum) when the product of the two-reactant concentration is the highest. Figure 17.13a indicates that
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