Steel is one of the major building block of the modern generation, it is used to make almost everything from bridges till cutlery, even wind turbines. But the way steel is produced – using coal – is making the climate change even worse.
On an average, two tonnes of carbon dioxide (CO₂) are released for every tonne of steel made. This forms for about 7% of the global greenhouse gas emissions. Cleaning up the steel production is one of the earliest keys to Earth’s low-carbon future.
Fortunately, a new way is emerging called “green steel”, which made using hydrogen instead of coal, giving us a huge opportunity for creating more steel with low- carbon future.
In steel-making oxygen is stripped from iron ore to produce pure iron metal. In the process of traditional steel-making, this is done by using natural gas or coal and in this process CO₂ is released. In the modern way- green steel production, hydrogen is made from a renewable source of energy which replaces the fossil fuels.
Steel-making is a bit of a complex process and is mainly achieved from one of the any three processes which are:
Globally around 70% of the steel is produced using the method of blast furnace.
In this process, processed coal (coke) is been used in the main part of the furnace. It also acts as a physically support giving structure for all the materials which are entering as well as leaving the furnace, along with other functions. It is also burnt till some extend at the bottom of the furnace and produces both heat and makes carbon monoxide, which helps us to striping oxygen from the iron ore leaving us with a metallic iron.
Around about 30% of the whole world’s steel is produced from recycled steel. Steel’s recycling rate is one of the highest recycling rates compared to any other material.Steel recycling for the most part is done in the arc furnaces, which is driven by electricity. Each tonne of steel produced using recycling method produces around about 0.4 tonnes of CO₂ – which is for the most part due to the emissions produced by the burning of the fossil fuels for the generation of electricity. If electricity was being produced from the renewable sources of energy, the output of CO₂ would be reduced with a significant difference.
DIRECT REDUCED IRON
“Direct reduced iron” (DRI) technology mostly uses methane gas to produce hydrogen and carbon monoxide, which is then used to convert iron ore into iron. This method creates CO₂ emissions, and electricity required more than the blast furnace method. But the overall intensity of the emission can be substantially lower.This method currently accounts for less than 5% of production in the world, but also offers the greatest opportunities for using green hydrogen.
Content by- Henna Majithia