Upgrading steel mill off gas to caproic acid and derivatives using anaerobic technology

Greenhouse gas (GHG) emissions from steel mills, mainly in the form of syngas, can be converted to ethanol and acetic acid via gas fermentation. Ethanol has a relatively low market value and its distillation from diluted broths is an energy intense and costly process. Diluted ethanol can be upgraded to higher value products caproic and caprylic acid by a secondary fermentation (biological chain elongation). These products can be also more easily recovered due to their low water solubility. The proposed approach has the potential to broaden the applicability of carbon capture and utilization, creating added value from GHG and decreasing these emissions.

Innovation goal
This project aims at developing a mixed culture reactor technology (TRL5) to valorize syngas fermentation effluent. It will define the best product extraction method, operational conditions and the required nutrient additions. It will allow ArcelorMittal to upgrade effluents from the Steelanol project, OWS to develop a new anaerobic reactor technology and Proviron to obtain and test syngas-based chemicals. A successful project will result in a new value chain from syngas to product that can be embedded in the chemical industry in Flanders.