A Comprehensive Modeling Analysis of Formate-Mediated Microbial Electrosynthesis*

Area of Science:

• Biotechnology
• Environmental Science
• Chemical Engineering

Background:

• Mediated microbial electrosynthesis (MES) is a promising technology for CO2 capture and conversion.
• Optimizing MES reactors is crucial for efficient production of carbon-based products.

Purpose of the Study:

• To develop and apply a multiphysics model for analyzing a formate-mediated MES reactor.
• To evaluate synthetic metabolic strategies for formatotrophic growth and assess process limitations.

Main Methods:

• Development and application of a comprehensive multiphysics model.
• Analysis of mass transfer limitations (O2 and CO2) and their impact on productivity.
• Evaluation of synthetic metabolic strategies and energy efficiency.

Main Results:

• The model predicts a biomass productivity of ~1.7 g L-1 h-1, limited by mass transfer.
• Synthetic metabolism offers a 30% energy efficiency improvement over the Calvin cycle (~21%).
• Carbon utilization efficiency is ~10%, necessitating gas recycling for improvement. Separating processes increases productivity to ~2.4 g L-1 h-1.

Conclusions:

• The multiphysics model provides insights into MES reactor design and optimization.
• Synthetic metabolism and reactor configuration are key factors for enhancing CO2 conversion efficiency.
• This research guides the development of processes for converting CO2 into renewable chemical feedstocks.