Cross-Linking at High Polymer Content

Influence of Cross-Linking at High Polymer Content 

As mentioned above, lo v polymer loading gives reaction rate curves with the shape observed for commercial macroporous catalysts (maximum for the reaction rate in the region of low methanol concentration). 

Different behavior was observed for the samples with higher polymer content. These curves show no maximum (Fig. 8.18). For all tested catalysts, activity for MTBE is nearly the same. Cross-linking in these cases is of minor importance. 

At low methanol concentrations the rate drops for all samples. The reason for this is that the polymer loading in the pore volume of the carrier causes a transport limitation for isobutene. So the typical activity pattern for macroporous resins cannot be observed. For the operation of an RD column this is beneficial drastic changes in the rate caused by fluid phase concentration changes do not occur. 

The whole packing in the column can be approximated with one rate, especially in the concentration range of industrial plants. 

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