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.