Work

Enhancing ethanol selectivity in microbial electrosynthesis from CO2 via digital process control

Year: 2026

Type: article

Abstract: The present work aimed to address the challenges of low efficiency and selectivity that are hindering the industrial adoption of microbial electrosynthesis (MES) for producing ethanol from CO 2. To this end, an electrically efficient MES cell with a low-gap stack configuration was operated and subsequently integrated into a bench scale system, enabling full control of the operating parameters to optimize ethanol production. In a preliminary test, low pH values (<5) along with low CO 2 partial pressure (< 0.2 atm) were identified as key parameters in triggering solventogenesis. Under these conditions, ethanol was produced with 64% selectivity and 57% coulombic efficiency. This resulted in an ethanol:acetic acid molar ratio exceeding 2.0, a final concentration of 3.35 g L −1 and a production rate up to 1.24 g m −2 d −1 . A digital process control was then implemented in the automated bench scale system, setting the pH between 4.5 and 4.7, fixing the dissolved CO 2 concentration range between 200 and 800 ppm and the total pressure to either 1.6 or 1.8 atm. Ethanol production rate boosted to 5.69 g m −2 d −1 while maintaining a similar production selectivity. Overall, the present work lays the foundation for the digital transformation of microbial electrosynthesis by showcasing the application of automated control systems to accurately regulate the operational parameters required to optimize ethanol production from CO 2 .

Source: Journal of CO2 Utilization

DOI: 10.1016/j.jcou.2026.103391

Authors: Meritxell Romans-Casas, Paolo Dessì, M. Dolors Balaguer, Sebastià Puig

Institutions: Universitat de Girona, University of Naples Federico II

Language: English

Topic: Microbial Fuel Cells and Bioremediation

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $3,360