As the world continues to strive to reduce its carbon emissions, the use of hydrogen in the production of DRI appears to play a key role as enabling solution.

Tenova is leading the way towards a more sustainable steel manufacturing worldwide. DRI plants using natural gas already can reduce more than 50% the CO2 emissions compared to the traditional blast furnace route, but the company additionally has CO2 absorptions units to capture approximately 250 kg for each ton of steel (using DRI technology), out of the 400 kg of CO2 totally produced during the process. In fact, this unique feature is applied also at both Guerrero and Puebla Ternium DRI modules and the CO2 is sold to the beverages industry as final user.

This may represent an important income stream. For example, in a steel mill that produces 5 million tons of steel per year, they save 250 kg of CO2 per ton of steel which, selling it at 25 dollars a ton, adds up to 31.25 million dollars annually.

In the recent time, Tenova increased their efforts in supplying technology for the manufacture of hydrogen-based steelmaking.

Paolo Argenta, Tenova executive vice president, highlighted the main company’s contributions, remarking the HYBRIT fossil-free steelmaking project in Sweden: “We started looking at hydrogen application for steelmaking a while ago. The first real achievement for us was when we landed the order to supply some equipment for their hydrogen-based DRI plant in Lulea. We also signed a contract to supply Salzgitter with a demo plant for them as well.”

In fact, Tenova HYL, its DRI competence center, has years of experience in implementing hydrogen as a reducing agent. Stefano Maggiolino, president & CEO, considers that the new demo plant in Salzgitter, Germany, is more a training center than a pilot because the technology is ready for the develop of the industry.

On November 2020, Tenova signed a contract with the HBIS Group in China to execute the Paradigm Project. The initiative consists in the development of a 600,000 tpy ENERGIRON DRI plant that foresees the use of hydrogen as reducing agent.

The mill will use make-up gas with a hydrogen concentration of 70% with total CO2 emissions of only 125 kg of CO2 per ton of steel.

The process scheme developed by the company with the use of hydrogen is exactly the same as used in the last 30 years. Back in the 1990s, the company already did tests with campaigns up to above 90% hydrogen, collecting data which allowed them to improve the design of the reactors and on how to produce low-carbon DRI. While the reduction of iron oxides with fossil sources always have CO2 as a by-product, using hydrogen will only produce water.
Tenova has full control of the technical solutions but sees as main challenge the availability of renewable energy and consequently green hydrogen at low cost in the short term. They expect this situation to change rapidly in the next future, as well as they wish that governments will more and more favour this energy transition, transforming steelmaking sooner than expected.

As a conclusion, Tenova believe the key indicators to monitor in this transformation path will be

1. The reduction of tons of CO2 emitted per ton of steel.
2. The amount of direct emissions vs. electrical energy used (related to green of fossil base energy production).
3. The amount of scrap vs. iron ore used.
4. The cost of “green” or “blue” hydrogen in relation to the natural gas price (this might include understanding the trends of renewable energy and CCU/CCS costs).
5. The cost of any “CO2 certificate” or taxation in different countries.
6. The willingness of the end customers to pay a premium for greener steel.