Steel’s contribution to a low carbon future
Steel is essential to the modern world and the use of steel is critical in enabling man to move towards a more sustainable future. Steel is fundamental in a greener world, whether in lighter more efficient vehicles, renewable energy generation, new highly efficient power stations and construction of smart electrical grids or transport infrastructure development and high energy efficient residential housing and commercial buildings.
Continuing to fulfill a positive role in our sustainable future comes with some major challenges:
- Energy efficiency
In the last 30 years the steel industry has reduced its energy consumption per tonne of steel produced by 50%. However, due to this dramatic improvement in energy efficiency, it is estimated there is now only room for marginal further improvement on the basis of existing technology. In the longer term it will be necessary to identify and introduce breakthrough steelmaking technologies that are viable. The greenhouse gas of most relevance to the world steel industry is carbon dioxide (CO2). On average, 1.9 tonnes of CO2 are emitted for every tonne of steel produced. According to the International Energy Agency, the iron and steel industry accounts for approximately 4-5% of total world CO2 emissions.
A critical element in reducing the carbon emissions from the steel life cycle is to optimise the use of recycled materials. Steel is an almost unique material in its capacity to be infinitely recycled without loss of properties or performance. This in combination with a long history of significant efforts to increase recycling rates has resulted in steel leading the recycling statistics, for example in cars and cans. Policies can provide further support for recycling by putting emphasis on recyclability and design for dismantling.
- Use of by-products
The production of steel results in the generation of by-products that can reduce CO2 emissions by substituting natural resources in other industries. For example, blast furnace slag is used by the cement industry allowing it to reduce its CO2 emissions significantly. Steel making slags are used as civil works aggregates thereby saving natural resources and environmental impact. Industrial by-products and mined raw materials need to be subject to the same legal framework.
- Use of finished steel
In many applications, steel has a very long life and as a result the contribution of modern steels in improving the energy efficiency of buildings, plants, machinery and transportation are much more important in helping man reduce its carbon footprint than the emissions associated with the initial steel production. For example electrical steels produce much more efficient transformers and motors thereby significantly reducing the total energy needed throughout their lives. This saving amounts to more than the CO2 emissions created from the original production phase. The key contribution from the steel industry is to work closely with its customers in optimising the design and use of steel in steel-using products.