A Comprehensive Modeling Analysis of Formate-Mediated Microbial Electrosynthesis

Mediated microbial electrosynthesis (MES) represents a promising strategy for the capture and conversion of CO(2)into carbon-based products. We describe the development and application of a comprehensive multiphysics model to analyze a formate-mediated MES reactor. The model shows that this system can achieve a biomass productivity of similar to 1.7 g L-1 h(-1)but is limited by a competitive trade-off between O(2)gas/liquid mass transfer and CO(2)transport to the cathode. Synthetic metabolic strategies are evaluated for formatotrophic growth, which can enable an energy efficiency of similar to 21 %, a 30 % improvement over the Calvin cycle. However, carbon utilization efficiency is only similar to 10 % in the best cases due to a futile CO(2)cycle, so gas recycling will be necessary for greater efficiency. Finally, separating electrochemical and microbial processes into separate reactors enables a higher biomass productivity of similar to 2.4 g L-1 h(-1). The mediated MES model and analysis presented here can guide process design for conversion of CO(2)into renewable chemical feedstocks.

Automated summary

Mediated microbial electrosynthesis (MES) is a promising strategy for capturing and converting CO(2) into carbon-based products, but it is limited by a competitive trade-off between O(2) gas/liquid mass transfer and CO(2) transport to the cathode.