Contacting modes crosscurrent

An attractive property of monolithic reactors is their flexibility of application in multiphase reactions. These can be classified according to operation in (semi)batch or continuous mode and as plug-flow or stirred-tank reactor or, according to the contacting mode, as co-, counter-, and crosscurrent. In view of the relatively high flow rates and fast responses in the monolith, transient operations also are among the possibilities. 

In our example, the lowest value of Y2 that can be attained with crosscurrent contacth with the inlet li uid stream sjtiit equally among N stages is 0.013. Theoretically, K] can be reduced to zero with counlercatrent contacting In our example. These results are plotted in Fig. 4.1-S. Thus, this simple exatiqile illustrates the relative effectiveness of the three classic contacting modes, which are listed in Table 4.1-1. 

Multistage Crosscurrent Adsorption The amount of adsorbent required for the separation of a given amount of solute can be decreased by employing multistage crosscurrent contact, which is usually operated in batch mode, although continuous operation is also possible. The required adsorbent is further decreased by increasing the number of stages. However, it is seldom economical to... 

Table I gives the values of the extraction factor (a) required for americium removals ranging from 80 to 99%. These required values of a are given for the three modes of extraction (single-contact, two stage crosscurrent, and two stage countercurrent).

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