Strongly coupled model for the prediction of the performances of an electrochemical reactor

- Through this model, a wider range of electrochemical systems can be investigated.
- Buttler-Volmer, linear and Tafel forms can be applied accordingly to the needs.
- Current density distribution is correctly predicted along the active plates.
- Deformations of the electrodes due to material deposition and corrosion are modeled.
- Results can optimize the performances of electrolytic cells on industrial scales.

A mathematical model is developed to investigate and predict the performances of electrochemical reactors. It is implemented with a finite volume method, and solved by means of the open source package OpenFOAM. The new solver, named ECpisoFOAM, deals with an intricate set of equations and boundary conditions which describe an electrochemical copper deposition system. The code uses the PISO algorithm for the transient incompressible flow field. A second predictor-corrector sequence combines mass fraction, electric potential and current density. It considers the convection, migration and diffusion mechanisms under the assumption of a dilute solution, mass conservation, and local electro-neutrality. The conservation of charges provides the electrical field which in turn allows the reconstruction of the tertiary current density distribution. At the electrodes, the presence of a charged double layer affects the behavior of the neighbor electrolyte. The effect of this interaction is modeled through the Butler-Volmer equation or its two commonly used simplifications: linear and logarithmic. Furthermore the fluid dynamic and the electrochemical modeling are coupled with the geometric changes of the active plates due to either material deposition or consumption of the electrodes. A dynamic mesh method has been integrated, increasing yet the level of coupling between electrical, chemical and fluid dynamic fields. Results are here presented and analyzed.