The climate crisis continues uninhibited, and the steel industry has a significant contribution. It is responsible for a quarter of all industrial greenhouse gas emissions. So far, the environmental savings in the sector are mainly due to steel recycling. Circular economy concepts that make the material flow even more efficient could change this, as the case study "More than recycling – the potential of the circular economy using the example of the metalworking industry" shows.
Wiebke Hagedorn, Researcher in Research Unit Production and Consumption Systems at the Wuppertal Institute, investigated together with researchers from three universities the extent to which the circular economy (CE) can increase the resource efficiency and cut emissions in the steel industry. Their recent case study illustrates how the production of an industrial machining knife can be improved by implementing various circular strategies.
The study states that a conventional production of one machining knife has an impact of 106 kg of CO2 eq and requires 1067.6 kg of resources. According to the researchers the main contribution to the aforementioned impacts can be traced back to the steel production, the grinding process, and the heat-treatment. In order to make these production steps and the general material flows in the steel industry more efficient and climate-friendly, the three principles of CE, narrowing, slowing and closing, should be applied. They state that at present, the strategy of closing the material flow is mainly addressed in the industry through recycling and thus only one of the principles would be applied.
"The case study shows the diverse possibilities to design production processes of steel products besides the well-established recycling route. Also, it can achieve a considerable reduction of environmental impacts. However, it also shows that circular solutions are not per se environmentally beneficial," explains Wiebke Hagedorn. The application of CE strategies can make processes like the steel production and heat treatment unnecessary, but might require additional auxiliary processes. In this case, returning the products on a global scale can compensate for the emission savings.
The article issuing the study "More than recycling – The potential of the circular economy shown by a case study of the metal working industry" is published online under the following link and will be issued in December 2022 in the journal of Cleaner Production, Volume 377.