The issue is particularly important for steel components as the steel industry represents more than eight percent of the world’s carbon dioxide emissions.
The key to evaluating a product’s true carbon footprint is through a life cycle assessment of the environmental impacts at every step from raw material extraction, materials processing, manufacture, distribution, use and end of life disposal or recycling.
To achieve this, manufacturers need a true understanding of the energy requirements and carbon dioxide emissions from cradle-to-grave. And in turn, this relies on the same data required by the steel manufacturer from cradle-to-gate.
Key differences in steel manufacture
Some steel manufacturers like Ovako enable their customers to significantly reduce the carbon dioxide footprint of their finished products. They achieve this by using the electric arc furnace (EAF) technique powered by low-carbon energy sources to process ferrous scrap into high-grade steel.
In comparison, around three quarters of steel is made by manufacturers that use the carbon-intensive basic oxygen furnace (BOF) method to process iron ore with heat from burning coking coal.
The result is that the carbon footprint for our hot-rolled bar steel is one sixth of the the world average – and buyers of steel can use that saving to create a competitive edge.
But that edge is only possible if the numbers stand up to scrutiny. To achieve this, Ovako submits Climate Declarations and Environmental Product Declarations (EPDs), which are independently verified and registered according to the ISO 14044 standard for environmental management and life cycle assessment.
Life Cycle Assessment in detail
Ovako has worked hard to reduce the emissions from its own processes. For example, by using the EAF process, optimizing scrap use for alloying and reusing or recycling residual materials or reusing heat. In addition, we focus on energy saving measures as well as sourcing energy from low-carbon generation.
We’re constantly making investments in many areas to improve the environmental performance at our mills. One recent example is the reconstruction of a rolling mill furnace, which lowered its CO2 emissions by 10 percent. In another example, we converted two pit furnaces to Oxyfuel, reducing CO2 emissions by 15 and 20 percent.
In the long term, this sort systematic improvement is making a significant improvement to our overall performance – and in turn, to our customers’ environmental performance.
Compare different steel products
With systems such as the Environmental Product Declarations, there are now increasingly improved opportunities for comparisons of carbon dioxide footprints between different steels.
Ovako achieves a total “cradle-to-gate” carbon dioxide footprint of around 450 kg CO2 / tonne of hot-rolled bar steel, compared with an estimated 2600 kg CO2 / tonne for the global average for all steel products.
Simply put, by switching to Ovako from an ‘average’ steel, steel buyers will save around two tonnes of carbon dioxide for every tonne of steel they buy.
In addition, ‘clean’ steels have lower levels of impurities that lead to high performance – lighter, stronger and more durable components. In turn, these enable manufacturers to further improve carbon footprint through lightweighting and long life.