Why green steel production will not happen in India anytime soon

Subject: Environment

Section: Climate change

Context:

Green steel production in India is unlikely to happen anytime soon, perhaps never.

Green steel:

‘Green steel’, or the steel produced through processes that do not emit carbon dioxide, essentially means using hydrogen as the ‘reducing agent’ (remover of oxygen) in steel production.
In other words, iron ore is basically iron oxide and hydrogen is used to pull oxygen away from iron oxide, leaving pure iron behind—to which a little carbon is added to make steel. Right now, carbon, in the form of coke, has been used for pulling away oxygen; when carbon joins hands with oxygen it becomes carbon dioxide, which is a Greenhouse gas.
Hydrogen can do the job of coke just as well.

India iron ore is not suitable for making green steel:

According to Australia’s Commonwealth Industrial and Scientific Research Organization (CSIRO), which is the country’s publicly funded research organisation and an expert in mines and minerals,66 per cent of India’s (and Australia’s) iron ore is not suitable for being made into green steel.
This is because Indian iron ore is low-grade. Low-grade iron ore can only be made into steel in blast furnaces—huge cooking pots in which iron ore is melted and made to combine with coke, before being poured into moulds for making steel slabs.
For technical reasons, green steel making requires the ‘electric arc furnace’ route;EAFs need high-grade ores, in which iron content is over 60 per cent.

Why can’t hydrogen be injected into a blast furnace to do the same job as coke?

This is theoretically possible, but there are two major problems.
- First, blast furnaces need to operate at high temperatures, or the order of 1,000-1,200 degrees C. Combustion of hydrogen releases a lot less heat compared with the combustion of coke.
  - Hydrogen must be pre-heated to high temperatures to provide sufficient heat for the blast furnaces.
  - Pre-heating hydrogen means using more energy, which must again come from renewable sources so that the steel qualifies for the ‘green’ label.
- Second, use of hydrogen results in ‘embrittlement’ of iron, leading to cracks and fractures in the metal.
  - To avoid this, you again need special alloys to resist hydrogen embrittlement.
Therefore, producing green steel in blast furnaces by injecting hydrogen as a replacement of coke is technically challenging and economically infeasible.
Blast furnaces are big emitters of carbon dioxide. A blast furnace capable of producing 2 million tons of steel annually will emit at least 2.5 million tons of CO2 a year.
In 2022, India produced 124.5 million tonnes of steel.

Alternative technologies:

It is possible to reduce CO2 in electric arc furnaces to some extent by replacing a part of the coke with used automotive tyres.
Apart from reducing dependence on coking coal, which India imports, these tyres contain about 7 per cent hydrogen, which helps.
The Indian Institute of Science, Bengaluru, is toying with the idea of replacing some of the coke with biochar.

HIsarna: a new technology developed by Tata Steel:

It is capable of slashing CO2 emissions by 80 per cent compared with the blast furnace route.
In a conventional blast furnace, a mixture of iron ore, coke and limestone – is put into the furnace and a blast of oxygen is sent in through a lance. The mixture melts and collects at the bottom. In HIsarna, the ore is liquefied in a high-temperature cyclone at the top and the molten ore drips to the bottom of the reactor, where powder coal is injected.
The technology removes a number of pre-processing steps and requires less stringent conditions on the quality of the raw materials used.
Since it is highly concentrated carbon dioxide that leaves the reactor, the system is “ideally suited for carbon capture and either storage (CCS) or use (CCU), without the need for a costly gas separation stage.

India-Australia Green Steel Initiative:

In June 2021, the Indian and Australian governments formed an India-Australia Green Steel Partnership to work on a range of research, technology and commercialisation projects over a three-and-a-half year period to accelerate the steel making value chain in both the countries.
CSIRO of Australia is working with the Institute of Minerals and Materials Technology (IMMT), Bhubhaneshwar, on a plasma technology for “very rapid melting of iron oxide using hydrogen”.

Promotion of Green Steel by Indian government:

Steel Scrap Recycling Policy, 2019 enhances the availability of domestically generated scrap to reduce the consumption of coal in steel making.
The Ministry of New and Renewable Energy (MNRE) has announced the National Green Hydrogen Mission for green hydrogen production and usage. The steel sector has also been made a stakeholder in the Mission.
Motor Vehicles (Registration and Functions of Vehicles Scrapping Facility) Rules September 2021, shall increase availability of scrap in the steel sector.
National Solar Mission launched by MNRE in January 2010 promotes the use of solar energy and also helps reduce the emission of steel industry.
Perform, Achieve and Trade (PAT) scheme, under National Mission for Enhanced Energy Efficiency, incentivizes steel industry to reduce energy consumption.
The steel sector has adopted the Best Available Technologies (BAT) available globally, in the modernization & expansions projects.
Japan’s New Energy and Industrial Technology Development Organization (NEDO) Model Projects for Energy Efficiency Improvement have been implemented in steel plants.