Residence time distribution, a simple tool to understand the behaviour of polymeric mini-flow reactors

A simple method for the determination of the residence time distribution (RTD) of different polymer-based mini-flow reactors has been developed. The flow patterns have been adjusted employing the axial dispersion model, allowing a quantitative comparison of the flow patterns of the different structures. The use of different pulse tracer experiments highlights the differences in reactor behaviour depending on the nature (gel vs. macroporous) and shape (beads vs. monoliths) of the polymeric materials used in the reactor preparation. Thus, reactors based on monolithic columns showed a superior performance in terms of flow distribution when compared to commercial bead-shaped packed polymers of different sizes and backbone structure, confirming previous experimental results. These differences can help to understand the different catalytic efficiency detected for these mini-flow fixed-bed reactors. The model presented can help to properly design new processes based on the use of continuous flow reactors facilitated by functional materials, which is becoming an essential goal nowadays, in particular in the context of developing new efficient and clean technologies.