CELBICON – Cost-effective carbon dioxide conversion into chemicals

The development and deployment of processes to utilize the greenhouse gas carbon dioxide (CO2) will be a central building block of a future climate-neutral and resource-efficient circular economy. Researchers from Fraunhofer IGB have developed and validated such a process chain in collaboration with partners from academia and industry in the course of the EU-funded project CELBICON.


CELBICON: Development new CO2-to-chemicals technologies

This has been achieved by combining CO2 capture, electrochemical CO2 conversion into intermediates and fermentation of these intermediates into value added chemicals. Each subsystem entered the CELBICON project as a stand-alone technology at a certain technology readiness level. During the CELBICON project these technologies will be further developed and integrated into a single, decentralized, cost-effective and robust technology platform operated at TRL5.

Combination of Capture, ELectrochemical and Biochemical CONversion technologies

Windmill and solar cells.
Windmill and solar cells.

Initial situation and project goal

The recycling of the climate gas CO2 as a carbon source is one of the main challenges of the 21st century. The development of novel processes is of key importance to counterbalance the increasing CO2 emissions and climate change [1]. Regenerative platform chemicals can be produced by integrating renewable energy in the operation of strategically important CO2-neutral processes. Because of the geographical distribution of available regenerative energy and CO2, the development of decentralized processes is of particular interest.

The EU project “Cost-effective CO2 conversion into chemicals via combination of capture, ELectrochemical and BIochemical CONversion technologies – CELBICON” aims at the development of new CO2-to-chemicals technologies by combining CO2 capture, electrochemical CO2 conversion into intermediates and fermentation of these intermediates into value-added chemicals. At the beginning of the project, the subsystems existed as individual technologies at a certain technology readiness level (TRL). During the CELBICON project, these technologies are to be further developed and integrated into a technology platform operated at TRL5. Key criteria for the developments are: (a) a modular and decentralized system, (b) high material and energy efficiency, (c) low investment and operating costs and (d) high robustness providing process variability.

Coupling electrochemistry and biotechnology in process cascades to convert CO2 into value-added chemical products

The targeted process chain was first demonstrated on a laboratory scale.

Adsorption of CO2 from air (direct air capture, DAC) is the first process step, achieved in a pilot plant provided by project partner Climeworks (Switzerland).

The captured CO2 is then converted electrochemically into formic acid. For this step, Fraunhofer IGB has developed tin-based electrocatalysts and a phosphate-buffered electrolyte. The first conversion step involves electrochemical reduction of CO2 to C1 intermediates on the cathode, while wastewater treatment was chosen for the valorization of the anodic current.

The C1 intermediates will be converted into higher-value chemicals such as lactic acid, isoprene and long-chain terpenes in an integrated fermentation process. In this way, the microorganisms used are optimized by tailor-made metabolic engineering aimed at efficient formation of the product and to support process performance.



CELBICON electrolyzer
CELBICON electrolyzer for CO2-based formic acid production.

Demonstration plant

During the last project year, the modules of the CELBICON plant were built and integrated into a single demonstration plant. For doing so, Fraunhofer IGB has designed and constructed the automated demonstration plant featuring an electrolytic cell from project partners Gaskatel (Germany) and Hysytech (Italy), in which the electrochemical conversion of CO2 captured from air into formic acid could be tested in a relevant operational environment. Upon commissioning the demonstrator plant, process validation and optimization will be completed at the end of the project.



In the CELBICON project it was demonstrated that electrochemically generated formic acid can be applied as substrate in a fermentation process to yield a product from the terpenoid metabolism. A fed-batch process at 10 L scale has been developed, enabling promising biomass yields based on optimized operational parameters. Product purification was successfully established, and it was demonstrated that 14% of the fed formic acid can be converted into a terpenoid dye.



 [1] UNEP. (2017) The emissions gap report 2017. United Nations Environment Programme (UNEP), Nairobi.

Project information

Project title

CELBICON – Cost-effective CO2 conversion into chemicals via combination of Capture and ELectrochemical and BIochemical CONversion technologies  


Project duration

March 2016 – November 2019


Project partners

  • Politecnico di Torino (Italy), Coordination
  • Technische Universiteit Delft (Netherlands)
  • Karlsruher Institut für Technologie KIT (Germany)
  • Université de Montpellier (France)
  • Agencia Estatal Consejo Superior de Investigaciones Cientificas (Spain)
  • Avantium Chemicals BV (Netherlands)
  • Climeworks AG (Switzerland)
  • GASKATEL Gesellschaft für Gassysteme durch Katalyse und Elektrochemie mbH (Germany)
  • Gensoric GmbH (Germany)
  • Hysytech S.R.L. (Italy)
  • Krajete GmbH (Austria)
  • M.T.M. SRL (Italy)


The research leading to results in this project receives funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement n°679050.

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