Peter Farber
University of Otago

Progress in Computational Fluid Dynamics Simulation of a Microbial Fuel Cell

P. Farber, J. Grabel, N. Kroppen, L. Potschke, M. Rosenbaum, D. Roos, J. Steffens, P. Ueberholz

Commercial Computational Fluid Dynamics (CFD) codes offer a great flexibility to model complex 3D geometries. They have many physical models on board, nevertheless bioelectrochemical reactions in a Microbial Fuel Cell (MFC) are not included.
In this talk, we discuss the extension of Ansys Fluent commercial CFD code to simulate a bioelectrochemical model of an anode in a microliter sized MFC. The biofilm on the anode is a mixed culture enriched with the electroactive model organism Geobacter sulfurreducens and is treated as a conductive material. Besides the stationary 3D Navier-Stokes equation for fluid flow and the species balance equation for acetate in the water and in the biofilm, the model consists of a model for the species mass fraction of acetate at the boundary between water and biofilm. Furthermore, we added a sink for acetate as a source for electrons and a stationary electric charge density balance equation in the biofilm.
Using this extended commercial CFD code allowed the model to analyse the bioelectrochemical conversion of acetate and current production in a microliter sized MFC.