Towards scaling up of the electrochemical production of Caro’s acid: Electrode size and/or stacking?

This work focuses on very important aspects associated with the scale up of electrochemical devices by facing a 4-times increase in the electrochemical production of the Caro’s acid, starting from a very efficient electrochemical cell that was developed and evaluated in previous works for this process. Thus, the effect is compared of (a) increasing the size of the electrodes by four by resizing, adapting, and manufacturing the cell prototype using 3-D printing technology and (b) that of stacking four cells to reach the same surface area, using different hydraulic connection configurations. Results demonstrate that the resizing of the electrochemical cell is more successful than stacking four cells. Resizing allows to obtain not only results that are comparable to those obtained by the lower scale cell but even to improve those results, because of the lower impact of edge effects. Regarding hydraulic connection, it was found that it is better to use parallel than series configuration. A simple phenomenological model is used to conclude that scavenging effects are higher when the series configuration is used. The resized cell was fully evaluated from the fluid dynamic behavior, pointing out its outstanding behavior.