Fundamental modeling of microbial electrosynthesis system using porous electrodes for CO₂-to-acetate conversion

Microbial electrosynthesis (MES) is an emerging carbon capture and utilization (CCU) technology that converts CO₂ into value-added chemicals using microbial catalysts powered by electrical energy. Advancing MES toward commercialization requires rigorous mathematical models for process optimization and scale-up. This study presents a fundamental model for an MES system designed to produce acetate from CO₂ incorporating real-world experimental conditions. Unlike existing models that focus on biofilm growth on nonporous metallic electrodes, the model emphasizes mass transfer, bioelectrochemical reactions, and biomass accumulation within porous graphite felt electrodes, which are widely used for their microorganism affinity and cost-effectiveness. Parameter values were obtained through model fitting with experimental data, accurately reflecting the behavior of the actual system. Simulation results confirmed that the fitted model accurately capture the dynamic behavior of MES system with porous electrodes. This work provides a solid theoretical foundation to support future optimization and the eventual commercialization of MES technology.