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Design and development of unconventional catalytic conversion processes using electrons, photons, and microorganisms

Problem statement

Our long-term commitment to sustainability and a circular carbon economy involves unconventional catalytic conversion processes. We study various processes assisted by electrons, photons, or microorganisms to produce biofuels, chemicals, electricity, or treated water. For example, bio-electro-chemical systems, including microbial fuel cells (MFCs), electrolysis cells (MECs), and photo-assisted cells (PA-MECs), are promising technologies to simultaneously produce renewable energy and clean wastewater using active microorganisms as biocatalysts.

Our work aims to synthesize multi-functional catalysts and reactors to enhance electrical conductivity, photo-efficiency, microbiological affinity, porosity, hydrophilicity, and surface area for carbonaceous electrodes. We work with materials such as graphene oxide, metallic nanoparticles, nitride and carbide basic materials, and MXenes.

We consider new platform technologies to produce renewable biofuel and chemicals and treat wastewater using the nanotechnology and reaction engineering approach as an innovative combination to increase the productivity of these processes.

Goals

  • Develop and scale up electro-photo-bio-catalyst and -reactors
  • Propose novel processes to clean wastewater and produce electricity, chemicals, and bio-hydrogen
  • Model and simulate fuel cell performance
  • Use innovative catalysts (anode and cathode material) and reactor designs to improve fuel cell performance
EPB2023

Related People

Hend Omar Mohamed
Muhammad Arief Shafarifky
Pewee Datoo Kolubah
Rushana Khairova

Related Publications

Microbial symbiotic electrobioconversion of carbon dioxide to biopolymer (poly (3-hydroxybutyrate)) via single-step microbial electrosynthesis cell

by Le, Mohamed, Kim, Yoo, Eisa, Jadhav, Nguyen, Eam, Myung, Castaño, Chae
Chem. Eng. J. Year: 2024 DOI: https://doi.org/10.1016/j.cej.2024.156635

Abstract

This study proposes an novel single-stage microbial electrosynthesis system (MES) that bioelectrochemically converts CO2 into poly(3-hydroxybutyrate) (PHB). This innovative approach utilizes a symbiotic co-culture of electroactive acetogenic bacteria and PHB-accumulating bacteria within a single reactor, bypassing the need for separate acetate production and extraction. Systematic optimization of key operational parameters, including applied voltage, carbon source, and cathode material, was conducted to maximize PHB production. Results demonstrate that using a voltage of 2.5 V yielded a 7.14-fold increase in PHB content compared to open circuit conditions. Furthermore, functionalizing the cathode with a conductive and hydrophilic PEDOT: PSS polymer coating significantly enhanced the system’s performance, resulting in a 1.5-fold increase in both acetate and PHB production compared to unmodified carbon felt electrodes. The long-term stability and effectiveness of the co-culture system were validated through comprehensive microbial and metagenomic analyses. Results revealed a significant enrichment of CO2-utilizing electrotrophs within the cathode biofilm, including Acetobacterium and Clostridium. Concurrently, a 4 to 14-fold increase in the relative abundance of PHB-biosynthesizing bacteria, such as Pseudomonas, Rhodobacter and Caulobacter was observed in the planktonic phase. This study offers a promising pathway towards a circular bioeconomy by enabling the valorization of CO2 into valuable bio-based products via single-stage MES, utilizing a symbiotic co-culture.

Keywords

EPB HCE CO2