Each tonne of steel produced on the planet requires emit approximately two tonnes of carbon dioxide into the atmosphere. It is not the biggest pollutant, but we are talking about 7% of the carbon dioxide produced globally by man (even more than what is emitted by combustion cars). This is a compelling reason for resources to be dedicated to look for a cleaner way to produce this material on which we are so dependent.
A Swedish company called SSAB seems to have found such a way and claims to have delivered already their first 'green steel' orders Volvo to produce the first trucks made of the material. If all goes well, it will be the first of many more.
The most common way of making steel requires the use of coal and coke in industrial furnaces, hence the carbon dioxide emissions mentioned above. In these furnaces iron and carbon particles are mixedThe steel is melted at high temperatures until a suitable mixture of liquid steel is obtained.
It is worth noting that this manufacturing process has a high recycling rate: up to 70% of the steel used can be recycled. But even with this renewability, the demand for steel is expected to grow too much to rely on it alone to justify the pollutant emissions caused by the use of coal in the furnaces. That carbon can be replaced by hydrogen by a method called Hydrogen Breakthrough Ironmaking Technology, o HYBRIT.
This method uses cleanly obtained iron particles, into which hydrogen, also obtained from environmentally friendly methods, is inserted. The result is a steel whose emissions caused during its creation are reduced to water. SSAB has been assisted by LKAB and Vattenfall, a Swedish state and government-owned mining and electricity company.
At the moment the plan is to start converting traditional factories steel to electric and green furnaces starting at SSA's Oxelösund facility around 2025. If there are no problems, we could have the first demonstrations of industrial steelmaking a year later, in 2026.
Bearing in mind that steel production involves 10% of Sweden's total steel emissions (and a 7% in Finland, for example), this method can be an important agent to further reduce pollutant emissions in these countries. And if the method is adopted in more countries, the reduction can be much greater.
