Green steel is a trend in the industrial sector. This metal is nothing more than fossil-free steel, i.e. it does not generate any carbon emissions during its production. The steel industry accounts for 8% of man-made CO2 emissions worldwide, which is why it is necessary to initiate a decarbonisation process that is also a great economic opportunity.
We tell you what green steel is and what its use would mean.
What is green steel?
As mentioned above, green steel is all steel that has been produced using processes that are completely free of CO2 emissions, using renewable energy and metal smelting processes that dispense with coke carbon, and therefore do not emit CO2 into the atmosphere.
Also called green steel or fossil-free steel, it still has a higher price tag than traditional steel, but its environmental and business benefits are clear.
These methods use cleanly obtained iron particles, to which hydrogen, also obtained by environmentally friendly methods, is added. The result is a steel whose emissions produced in its creation are reduced to water.
Decarbonising steel
Making steel with hydrogen will be a real challenge for the steel industry in the coming decades. Currently, low-carbon steel production accounts for 28% of global steel production.
Initial steps to reduce emissions from steel production necessarily involve making more efficient use of steel and increasing its recycling rate, but this is not enough. Future projections indicate that at least half of steel demand will still need to be met from iron ore, making it essential to develop new, more environmentally friendly technologies.
To this end, work is being done on metal smelting processes that use only air, water and clean energy (from renewable sources) and also on processes based on electrolysis to work the ore and obtain the metal without emitting greenhouse gases in the process. However, the transformation of current processes to completely eliminate CO2 is a major challenge, especially when it comes to metals that have been worked with carbon for centuries.
It should not be forgotten that we are dealing with one of the most polluting and energy-consuming industries on the planet. Its manufacture takes place in blast furnaces that use fossil fuels such as coal, oil or natural gas to achieve the high temperatures and chemical reactions necessary to produce the metal. It is here that 8% of the world’s man-made C02 emissions are emitted.
From green steel to green aluminium
The main aluminium smelting process is the Hall-Héroult process: aluminium oxide, obtained from bauxite, is dissolved with aluminium ore in molten cryolite and, using carbon electrodes, aluminium is obtained. This accounts for 1% of global greenhouse gas emissions. Most of the emissions are due to the aluminium smelting process and the degradation of the carbon anodes.
Following in the footsteps of green steel, companies are already starting to work on a completely emission-free aluminium smelting process.
The future of metallurgy
For this sustainable industry to happen, collaboration between companies, universities and the public sector is vital. Precisely, one of the Sustainable Development Goals of the United Nations is to Build resilient infrastructure, promote sustainable industrialisation and foster innovation, where it is proposed to “promote inclusive and sustainable industrialisation and, by 2030, significantly increase the contribution of industry to employment and gross domestic product, in accordance with national circumstances, and double that contribution in the least developed countries”.
As a summary, we can see that the decarbonisation of steel is possible and that there are already very promising options for making steel sustainable.