Covestro and Recticel convert flue gases from the steel sector into plastics and insulation panels

Making insulating materials and high-quality plastics from flue gases from the steel industry? With the European research project Carbon4PUR, chemical company Covestro and insulation specialist Recticel prove that it is possible. Steel producer ArcelorMittal and the University of Ghent also contributed to the development of a new technology to convert the blast furnace gases from steel plants into raw substances for valuable materials.

Is it possible to recycle the CO2 emissions released during steel production into a raw material for plastics? This is possible, according to the results of Carbon4PUR, a cross-sectoral research project funded by the European Union. Fourteen industrial and academic partners from seven countries conducted joint research work for three and a half years. Amongst them: Covestro, ArcelorMittal, Recticel and the University of Ghent.

New technology for recycling CO2
The consortium investigated new technologies with which blast furnace gases from steel plants can be converted into polyurethane, a plastic with many applications. It was especially important to investigate how carbon monoxide (CO) and dioxide (CO₂) from the waste gases of steel production can be used as a carbon source for the production of polyols, important intermediates for insulation materials and polyurethane-based coatings.

It was the University of Ghent that was responsible for the purification of the residual gases into a mix of carbon monoxide and carbon dioxide. Conclusion: both ecologically and economically, the new technology is judged to be favourable. The research partners have succeeded in producing polyols on a lab scale using carbon monoxide (CO) from gas mixtures. In the new intermediate product, 27 percent CO could be bound, so that petroleum can be saved.

Insulation panels and sports floors
The Carbon4PUR technology has already been successfully scaled up to semi-industrial dimension by the Belgian insulation manufacturer Recticel. For example, it has been shown that polyols based on the new Carbon4PUR technology can be processed into rigid foam insulation panels, with technical specifications comparable to the market reference.

The insights that Carbon4PUR has provided can also have positive consequences for the CO₂ technology that Covestro has developed. The chemical company, in collaboration with Recticel, created the sustainable polyol cardyon® that contains up to 20 percent carbon dioxide instead of crude oil. This is already used today in the production of foam fillings for mattresses, binding agents for sports floors or elastic fibres.