BACKGROUND: Microbial electrosynthesis is a carbon capture technology capable of transforming CO2 into valuable organic compounds. The aim of this article is to model the simultaneous production and separation of acetate in an anion-exchange membrane microbial electrosynthesis cell which employs CO2 as feedstock. RESULTS: The maximum amount of acetate product produced was 0.72 mmol after 19 operational days. Simultaneous production and separation of acetate began after 4 days when 0.95 mol m(-3) and 0.04 mol m(-3) of acetate were detected in the cathode and anode MES cell chambers, respectively. A model that fits the simultaneous production and separation of acetate in the microbial electrosynthesis cell was successfully developed and validated. CONCLUSION: The microbial electrosynthesis model developed in this work can be used to predict the product concentrations of a carbon capture technology which simultaneously produces and separates acetate product. (C) 2016 Society of Chemical Industry