Bioconversion of Carbon Dioxide in a Novel Reactor Type

As the global population increases and fossil fuel consumption rises, there is an urgent need to develop technologies for producing chemicals and fuels from renewable resources. One promising alternative is the bioconversion of CO2.

The bioconversion of CO2 can be carried out by methanogenic and acetogenic microbial consortia via the Wood-Ljungdahl pathway. However, this approach remains challenging on a commercial scale due to the mass transfer limitations, low microbial growth rates under anaerobic conditions, and the need to supply reducing power, usually accomplished with H2 addition via water electrolysis. In the frame of this PhD project, we will design, construct and investigate a novel reactor type that can address these challenges and facilitate a more efficient and effective bioconversion of CO2 using an electroactive methanogenic and acetogenic microbial consortium. Ultimately, this novel reactor will boost the economic competitiveness of gas fermentation technology to produce chemicals and fuels.

The objectives of the PhD project are:

• Designing and constructing the prototype of the novel reactor
• Cultivating, enriching, and characterising electroactive and electro-tolerant methanogenic and acetogenic microbial consortia
• Developing a method for measuring the biofilm thickness that is particularly suitable for anaerobic microbial films
• Starting up, operating and characterising the novel reactor concept concerning performance indicators, i.e. product yields and productivity
• Reaching proof-of-concept and benchmarking the efficiency of the novel reactor against this of a conventional, yet very efficient, Trickle Bed Reactor.
• Techno-economic analysis of the developed concept
• Further development of an existing model for optimising the design and scaling-up of the novel reactor.

Main supervisor:
Hariklia Gavala

Co- supervisor:
Ioannis Skiadas
Alexander Shapiro