Chemical Engineering Journal, Vol.363, 337-348, 2019
Scalability of 3D printed structured porous milli-scale reactors
This study addresses the scalability of in-house designed, and 3D printed structured porous reactors for liquid-liquid reactions. The base structure of these porous reactors consists of cylindrical fibres in defined geometrical arrangements. Their scale-up was realized by increasing the reactor diameter by a factor of 1.5 and 2 respectively while keeping the fibre dimensions constant. Also, the effect of altering the fibre dimensions in proportion to the scale-up factor was assessed. The reactors were characterized in terms of their biphasic heat and mass transfer properties. In stratified flow, the scaled-up structured porous reactors exhibited high interfacial mass transfer coefficients (k(L)a) at residence times <10 s, whereas in Taylor flow an overall drop in k(L)a values was observed. Furthermore, the highest biphasic heat transfer coefficients were found for the structured porous reactors with a scale-up factor of 1.5. Moreover, the structured porous reactors were applied to industrially relevant reactions. For the oxidation of nonanol, the scaled-up reactors showed an overall drop in yield, nevertheless with two folds production rate at same pressure drop. For the relatively slow C-N cross-coupling reaction, larger yields were realized by arranging scaled-up reactors in series at same total residence time. Specifically, an arrangement of 8 reactors with a scale-up factor of 2 in series resulted in six times higher production rate than a conventional packed-bed reactor but without any additional pressure drop. For the considered range of residence times, keeping the fibre dimensions constant while increasing the reactor diameter was observed to be advantageous.
Keywords:Scale-up;Liquid-liquid reactions;Interfacial mass transfer;Biphasic heat transfer;Structured porous reactors;3D printed reactors