Optimization of a cell for the electrochemical synergistic production of peroxoacetic acid

Abstract

Highlights Peroxoacetic acid (PAA) is efficiently produced electrochemically from acetic acid  The production of hydrogen peroxide is crucial for an efficient accumulation of PAA  BDD is superior to DSA as anode material for PAA production  High current densities hinder the accumulation of PAA and hydrogen peroxide  Flow from anode to cathode improves the process of PAA production

Reactor design as a critical input in the electrochemical production of peroxoacetic acid

“…The first one is the flow pattern of both reactors. In our previous work, it was demonstrated that when the fluid passed first through the anode chamber and then through the cathodic side of the reactor (flow anode–cathode), the rate of PAA production was higher than with a cathode–anode configuration. In the case of the jet reactor presented in this work, it is difficult to work with an anode–cathode configuration because the inlet of the reactor in the anode side is perpendicular and a high tangential velocity is required to assure an adequate flow of air through the jet device.…”

“…First, we presented a prototype in which we performed the production of PAA from CH 3 COOH aqueous solutions combining the oxidation of CH 3 COOH by boron-doped diamond (BDD) anodes and the cathodic production of H 2 O 2 using a carbon-based gas diffusion electrode (GDE). 13,14 With this design, we observed a clear synergistic effect when combining both the anodic and the cathodic processes in the production of PAA, resulting in the highest concentration reported so far in the literature for the electrochemical production of PAA. Moreover, in those works, we demonstrated that the flow direction (from cathode to anode or vice versa) played an important role in the efficiency of the process.…”

“…Although the specific electric charge and concentration are generally used in this type of plots to compare results, these two parameters were not be used in this case to compare the production rate, because they both depend on the reaction volume, and this parameter varied between the different tests. In all cases, the working current density was 27 A m −2 , the optimum value obtained in a previous work with a reaction volume of 400 mL . As these tests are the basis for evaluating the influence of the volume:area ratio, they were performed in triplicate, with the standard deviation represented as error bars.…”

“…Two different electrochemical cells were used and compared in the present work. The first cell (referred to in this manuscript as GDE reactor or GDE device), described in detail in previous works, consisted of an electrochemical reactor with three chambers: anode, cathode and gas chamber. The total volume of the raw solution was varied from 0.4 to 0.8 L in the first part of the work (section 3.1).…”

“…Based on this fact, our research group recently proposed two advances in the design of electrochemical reactors that can be used in the electrochemical production of PAA. First, we presented a prototype in which we performed the production of PAA from CH 3 COOH aqueous solutions combining the oxidation of CH 3 COOH by boron‐doped diamond (BDD) anodes and the cathodic production of H 2 O 2 using a carbon‐based gas diffusion electrode (GDE) . With this design, we observed a clear synergistic effect when combining both the anodic and the cathodic processes in the production of PAA, resulting in the highest concentration reported so far in the literature for the electrochemical production of PAA.…”