Bioelectrochemical chain elongation of CO2 to caproate: electrification of biotechnology

The world population is growing and the amount of arable land becomes scarce. Therefore, solutions are needed for a more efficient use of the available land and water for the production of biochemicals. Capturing CO2 and utilization of waste streams to (re)produce chemicals in electricity driven microbial electrosynthesis represents an effective solution to circularly utilize waste-resources from our society.

Technological challenge

Bioelectrochemical chain elongation (BCE) is a promising technique to produce caproate from CO2 or evenly organic waste streams. Caproate is a platform chemical that can be used as animal feed additive, plant growth promotor or for the production of biodegradable plastics or fuels. In BCE, water is oxidized to release electrons which take-up renewable electrical energy. The highly energetic electrons are supplied to the biofilm where a CO2 elongating biofilm grows.


The current process yields can be further improved for practical application of the process. And also the working mechanisms of this process remain to be further revealed. The main focus of this research is to investigate the role of the biofilm and the changes therein in the optimization of the electron flux between the cathode and the biofilm. By better understanding of these fluxes we can develop new ways to steer the bioelectrochemical processes.


Research challenges

  • Gain insights about the biofilm composition and the role of different microbial groups in the chain elongation process
  • Study the electrode surface and the changes therein during development of the biofilm
  • The project is performed in collaboration with the Biobased Chemistry and Technology (BCT) group of WUR.