- December 11, 2021
- Posted by: BiconAdmin
- Category: Steel Making Technology
HYBRIT is a ground-breaking effort to reduce CO2 emissions and de-carbonise the steel industry.
HYBRIT aims to replace coking coal, traditionally needed for ore-based steel making, with hydrogen. The result will be the world’s first fossil-free steel-making technology, with virtually no carbon footprint.
During 2018, work started on the construction of a pilot plant for fossil-free steel production in Lulea, Sweden. The goal is to have a solution for fossil-free steel by 2035.
If successful, Sweden’s CO2 emissions can be reduced by 10% and Finland’s by 7%.
Factors like the price of electricity, coking coal and carbon dioxide emissions are crucial for the possibility of making fossil-free steel commercially viable in the long term. It is convinced that fossil-free steel will be able to compete with traditional steel in the future.
EFFECTS IN QUALITY & PERFORMANCE:
Although we are talking about fossil-free steel, the major change in the process is actually replacing the traditional iron-making process. The downstream conversion of iron into steel will use the same advanced technology as today, which means that the product properties will not be affected/will remain unchanged.
RECENT NEWS / DEVELOPMENT:
September 02, 2020 – SSAB joins the European Clean Hydrogen Alliance (ECHA):
In July 2020, the European Commission presented its EU Hydrogen Strategy, underlined by the launch of the European Clean Hydrogen Alliance. The European Commission acknowledges the growing momentum for hydrogen as an essential energy carrier for the de-carbonization of our society. SSAB will be a member of this network, which currently has more than 250 members.
The European Clean Hydrogen Alliance is set to facilitate the implementation of actions of the recently published EU Hydrogen Strategy. By building up a clear and concrete pipeline of renewable or low carbon hydrogen projects and investment plans, the Alliance will play a crucial role in achieving the commitment of the EU to become carbon-neutral by 2050.
August 31, 2020 – SSAB, LKAB and Vattenfall to start up the world’s first pilot plant for fossil-free steel:
At the plant, HYBRIT will perform tests in several stages in the use of hydrogen in the direct reduction of iron ore. The hydrogen will be produced at the pilot plant by electrolyzing water with fossil-free electricity. Tests will be carried out between 2020 and 2024, first using natural gas and then hydrogen to be able to compare production results. The framework for HYBRIT also includes a full-scale effort to replace fossil oil with bio-oil in one of LKAB’s existing pellet plants in Malmberget in a test period extending until 2021. Preparations are also underway to build a test hydrogen storage facility on LKAB’s land in Svartöberget in Luleå, near the pilot plant.
August 05, 2020 – Successful trials using fossil-free fuels in the pellet process:
Full-scale tests are currently under way to replace fossil oil with bio-oil in one of LKAB’s existing pellet plants in Malmberget, reducing emissions for the operation by 40 per cent during the test period, which will last until 2021. These tests are part of the pilot phase in HYBRIT, where the overarching goal is to be first in the world with a fossil-free value chain from mine, using fossil-free electricity and hydrogen, to finished steel product, thereby cutting Sweden’s carbon dioxide emissions by ten per cent.
GROWING GLOBAL DEMAND:
Steel is an important enabler for building the modern society, including industry, innovation and infrastructure.
Per day demand of steel in 2016 was 1,600 MT (400 MT recycled scrap based + 1,200 MT ore based). According to a forecast, per day demand of steel in 2050 will be 2,800 MT (1,400 MT recycled scrap based + 1,400 MT ore based).
The steel industry is one of the highest carbon dioxide emitting industries, accounting for up to 7% of global, and 10% of Swedish CO2 emissions. Sweden has set a national target to reach zero net emissions of carbon dioxide by the year 2045,
DECOUPLING OF CARBON DIOXIDE AND ENERGY:
At the steelmaking site, iron ore is converted to metallic iron by reduction of the iron ore pellets with coke in a blast furnace. The iron oxide and carbon then react to form CO and CO2 gases, as well as metallic iron.
An alternative to the dominant blast furnace ironmaking route is to use the so-called direct reduction process where natural gas replaces coke as the main reductant, and the main product is solid sponge iron. The iron then needs to be melted using an electric arc furnace, before steel is produced. Currently, this gas-based direct reduction process is not used in Sweden, but is an option in other parts of the world where natural gas is in abundance.
Chemical reaction in this method:
Iron ore pellets + Hydrogen (H2) = Sponge iron + Water (H2O).
Difference between a Blast Furnace Route and HYBRIT Route is shown in the below diagram:
When calculating initial emissions of the current dominant production process, both direct and indirect emissions were included. In Sweden, the carbon dioxide emissions using current technology are 1.6 – 1.7 tonnes of CO2 per tonne of crude steel, compared to the estimated 2.0 – 2.1 tonnes of CO2 for a typical integrated steel plant in Western Europe. The result can be explained by differences in the electricity mix, with more renewable sources available in Sweden. Another factor is the high level of energy efficiency in the Swedish industry, where LKAB and SSAB are leading operators in terms of energy and CO2 efficiency.
For implementation of this project some functioning production system in place needs to be reconstructed. Replacing major parts of the existing infrastructure in steelmaking will be very expensive. Therefore, careful planning is important.
The estimated total cost per tonne of crude steel has been calculated based on current commodity and energy prices. The indication is that the production cost for steel via the HYBRIT route is approximately 20 to 30 per cent higher than for the reference case.
The main factors affecting HYBRIT in the long run are mainly price developments for coking coal, electricity and emission allowances. If coking coal prices increase, it will benefit the HYBRIT business case, while increasing electricity prices will weaken HYBRIT. Also, future developments of the emission trading system EU ETS will have an impact.
COMPARISON BETWEEN PRESENT PROCESS & HYBRIT PROCESS OF STEEL MAKING:
|Present Process||HYBRIT Process|
|In the pelletising plant, the fine iron ore concentrate is dewatered, and a binding agent is added before the concentrate is rolled into 10-millimetre pellets. The pellets are dried, preheated, sintered, and cooled down before storage and transportation to steel plants. The magnetite ores in northern Sweden are especially suitable for such processing. During the process, the magnetite is oxidised into hematite. This reaction releases heat, which replaces about two thirds of the fossil fuel needed when pellets are produced from hematite concentrate.||The fossil fuel in ore processing will be eliminated with an increased level of energy efficiency and by switching to fossil-free sources of energy.|
|Coke Production||Hydrogen Plant|
|Coke is a stable fuel and reducing agent with a high carbon content, made from coal. Parts of the volatile matter in coal are used as energy for the high temperature baking process in coke production.||Hydrogen production takes place by electrolysis of water into hydrogen gas and oxygen. Renewable electricity is the primary energy source. Electrolysis is a mature technology, and principally, there are no barriers to building a large-scale plant.|
|Blast Furnace||Direct Reduction|
|The iron ore and coke is added to a process designed to release oxygen from the iron ore according to the simplified reaction: iron ore + carbon → iron + carbon dioxide. This takes place in a shaft furnace where the solids are charged to the top of the furnace, and preheated air is injected in the lower parts to enable an efficient heat transfer. The result is a molten hot metal consisting of iron, with 5% of dissolved carbon.||The existing direct reduction method needs to be adapted to reduction with hydrogen to eliminate carbon dioxide emissions. The off-gas of the reduction process would be water, according to the simplified reaction:
iron ore + hydrogen → iron + water.
The result is a solid porous sponge iron, suitable for steelmaking.
|Oxygen Converter||Electric Arc Furnace|
|The hot metal is treated with oxygen gas to lower the carbon content and form molten steel. The reaction releases heat, which is utilised to melt an additional 10-20% of steel scrap, before the liquid steel is tapped into a ladle, where the final chemical composition and the temperature of the steel is adjusted. After this, the steel is cast into crude steel slabs in a continuous caster.||The Electric Arc Furnace (EAF) is used for heating and melting charged materials by means of electric current. The use of EAFs allows steel to be made from up to 100% scrap metal, or as in the HYBRIT concept, from a mix of direct reduced iron and scrap. Similar to the reference process, the liquid steel is tapped into a ladle where the final chemical composition and the temperature of the steel is adjusted, before it is cast into crude steel slabs in the continuous caster.|
|Carbon dioxide originates from the blast furnace, coke making, decarburisation of hot metal in the converter process, and fossil fuels used in the pelletising process.||CO2 emissions will be reduced dramatically, although minor emissions can still arise because of the use of certain process equipment, and because small amounts of coal must be used in the manufacturing process.|
Diagram of present process of steel making showing Carbon emission in different stages:
Diagram of HYBRIT process of steel making showing Carbon emission in different stages:
Renewable Electricity – Substitution of Coal:
The most significant steps with regards to CO2 reduction are associated with the phasing out of blast furnaces, substituted by hydrogen-based direct reduction plants and electric arc furnaces. The primary iron source in steel plants will then shift from blast furnace iron to hydrogen-based direct reduced iron, using the HYBRIT production principle.
After this development, electricity from renewable sources will be the primary energy carrier and consumption will increase in the order of 15 TWh, primarily to be used for hydrogen electrolysis and steel melting processes.
- Carbon-free processing – Without carbon added in any substantial amount, there is a need to understand mechanisms and define process principles.
- Hydrogen Production – It will be based on existing commercial technology, yet to be proven on a large scale.
- Hydrogen Storage – It plays an important role in the value chain economics and integration. Technology for large-scale hydrogen storage is still untested.
- An Operating Practice needs to be established in the new process to function as a stand-alone unit.
- Electricity demand – Renewable Electricity generation & transmission to the future production sites plays an important role to secure the foreseen increased demand of electricity.