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Recycled steel lowers the carbon footprint

The building sector produces a significant part of the global emissions today. An important step on the road to sustainable practices is to lower the footprint from embodied carbon in products.

Embodied carbon refers to the amount of carbon dioxide (CO2) emissions that are produced in the process of manufacturing a product. It takes into account all the energy and resources required to create and sustain that product. By understanding and reducing embodied carbon, we can make more environmentally friendly choices.

Life cycle assessment (LCA) is an excellent tool to calculate embodied carbon and then use Environmental Product Declarations (EPD) to publish the result.

An EPD is a standardized and independently verified document that provides transparent and scientifically-based information about the environmental performance of a product. EPDs are typically developed in accordance with international standards. They require a comprehensive life cycle assessment that evaluates various factors, including resource consumption, energy use, greenhouse gas emissions, air and water pollution, and waste generation. The EPD document is a valuable tool to make informed decisions, allowing for comparisons between products of similar types.

When it is clear where the embodied carbon comes from, it is possible to make choices to reduce the levels. For example, using renewable energy sources during manufacturing, designing products that require fewer resources to make, and recycling or repurposing items instead of throwing them away can all help reduce embodied carbon. In the case of manufacturing, a lot of the embodied carbon comes from the materials involved. Steel and aluminum, for instance, can have significant environmental impact.

Steel from recycled scrap metal
As for steel, some options have begun to emerge. There are steels that are certified in a system similar to energy attribute certificates. This, however, does not actually lower the carbon footprint very much in reality. A better option would be to use a steel which is at least partly manufactured from scrap metal, thereby reducing the amount of additional embodied carbon. Another way to go would be newly produced carbon-free steel, but the volumes produced today are still quite low. However, it will be worth looking at again at some point down the road. At this moment in time, switching to a steel with a high ratio of recycled scrap metal is clearly the best option.

At Swegon we have actively begun to work to lower the embodied carbon in our products. We commissioned an EPD for the GOLD RX 012 air handling unit, manufactured in Kvänum, Sweden. The EPD showed that the bulk of the embodied carbon, carbon dioxide from the entire manufacturing process, came from the materials, with steel standing for more than 60 percent of the carbon dioxide equivalents. This made finding a replacement steel with a lower carbon footprint a priority.

After discussions with the steel manufacturer ArcelorMittal, we have chosen to work with a steel called XCarb RRP, with RRP standing for “recycled and renewably produced”. It has a recycled steel content ratio of at least 75 percent. In addition, the manufacturing process uses electric arc furnaces that run on 100 percent renewable energy. The result is a steel with at least 70 percent lower carbon footprint compared with traditional steels. Based on the existing EPD for GOLD RX 012, the total global warming potential is expected to be reduced by approximately 20 percent with the transition to XCarb RRP steel, given that all the steel is replaced.

The Swegon plant in Kvänum has received a test shipment of 30 tons XCarb RRP, in order to learn how the steel will perform in the production process, with another 270 tons ordered for further testing during Q3 2023. The long-term goal is to replace at least 90 percent of the production steel – 7500 tons per year in total – with XCarb RRP.

If the trial at Kvänum gives encouraging results, the plan is to continue forward. We believe that this is a necessary step toward lowered environmental impact. There is still a long way to go but we have started with the actions that will bring the biggest effects in the shortest time possible.

For more information see our press release about our Swegon GOLD RX and fossil-free steel and also read our expert’s blog about environmental product declarations (EPDs).