Carbon Capture and Storage in Iron and Steel Industry

Carbon Capture, Use and Storage or Carbon Capture, Utilisation and Sequestration (CCUS) technologies is an effective solution for reducing carbon emissions from the industry. CCUS technologies separate and capture the CO₂ generated during the iron and steelmaking process. The captured CO₂ gets chemically converted into other products such as plastics, concrete or biofuel, or used in enhanced oil recovery (EOR). Using carbon capture and storage (CCS), the CO₂ is stored permanently underground. While the goal of a CCS supply chain network is to reduce the CO₂ emissions, CCUS aims at maximising the revenue or profit from CO₂ utilisation since it can be used or sold as feedstock. Due to the potential to provide CO₂ as feedstock to synthesise materials, chemicals and fuels, CCUS plays an important role in CO₂ reduction and should be complementary to the geological storage in a CCS system. The main advantages of CCUS are:

1. CCUS can be used to retrofit existing power and industrial plants, that emit large volumes of CO₂.
2. CCUS can be adopted to tackle emissions in sectors where other technology options are limited.
3. CCUS is an enabler of least-cost low-carbon hydrogen production.
4. CCUS can remove CO₂ from the atmosphere by combining it with bioenergy or direct air capture to balance emissions that are unavoidable or technically difficult to abate.

CCUS in Steel industry

Iron and steel while vital for the development of modern civilization, is associated with significant amounts of greenhouse gas emissions. On average each ton of steel produced results in about 2 tons of CO₂ emissions, with a wide range depending on production pathway used. The iron and steel industry in contributes to around 7% of global GHG emissions. In the primary steel making route, the coke oven, blast furnace and basic oxygen furnace create many types of co-product gases, including nitrogen, carbon dioxide, carbon monoxide, hydrogen, methane and more. Consumption of carbon-based electrodes in an electric arc furnace releases CO₂. The use of lime fluxes, to remove impurities and promote liquidity, also generates CO₂ emissions. There is no single solution to CO₂ free steelmaking, and a broad portfolio of technological options is required, to be deployed alone, or in combination as and when the conditions permit. Decarbonizing the production processes, switching to low emission production pathways, adopting low emission raw materials and fuels like green hydrogen, increasing recycling rates, increasing material and energy efficiencies are increasingly gaining interest to decarbonize the iron and steel sector.

Al Reyadah in Abu Dhabi launched by Emirates Steel in 2016 is the world’s first fully commercial CCUS facility for the iron and steel industry. Current international initiatives like ULCOS and HYBRIT, evolving government policies and incentives, and pilot projects are helping to improve process economics and shedding light on industrial viability.IEA estimates that to reach Sustainable Development Scenario (SDS) targets, one hydrogen-based DRI plant per month must be deployed from the moment of market introduction, while one CCUS-equipped plant must be deployed every 2-3 weeks from 2030 onwards. Current international initiatives like ULCOS and HYBRIT, evolving government policies and incentives, and pilot projects are helping to improve process economics and shedding light on industrial viability.

CCUS applications in Steel Industry

• Enhanced oil recovery (EOR): In EOR, CO₂ is injected into mature oil fields in their final phase of extraction. The biggest demand for CCUS comes from EOR. While it may seem unintuitive that extracting extra oil using CO₂ can lead to climate benefit, a large proportion of the CO₂ injected into oil fields for EOR purposes (around 90 - 95 %) is permanently sequestered, trapped in the geologic formation where the oil was once trapped. CO₂ captured from the Emirates Steel plant, located in Abu Dhabi, UAE, is currently being used in EOR operations. Annually up to 800kt of CO₂ is captured and injected into the Abu Dhabi National Oil Company’s oil reservoirs.

• Chemical production: This involves conversion of captured steel industry waste gases into useful products.
  • LanzaTech piloted a plant for converting steel plant waste gases to ethanol at New Zealand Steel in 2008. The process was subsequently commercialised, with the first plant beginning operation in 2018 in China at Shougang Steel. The plant produced 30 million litres of ethanol for sale in the first year of operation. A large scale plant at ArcelorMittal in Ghent, Belgium began operation in 2022. The Steelanol plant is expected to produce 80 million litres of advanced ethanol once production reaches full capacity, almost half of the total current advanced ethanol demand for fuel mixing in Belgium.
  • Thyssenkrupp’s Carbon2Chem project developed a pilot phase in 2018 looking to produce ammonia and methanol from steel off-gases, with the aim to develop an industrial scale plant by 2025.
  • The Carbon4PUR project by a consortium of 11 partners across Europe, including ArcelorMittal, is piloting converting steel off-gases to polyurethane foams and coatings with a capacity of 20 t/yr.
  • The FReSMe project, a consortium of European partners including Tata Steel and SSAB, is piloting steel off-gas conversion to methanol with a capacity of 1 t/day.

• Carbon Mineralisation: In this method, the captured CO₂ is used to react with a mineral or industrial waste compound which is used for applications like construction
• Concrete Curing: Here, the captured CO₂ is stored as unreactive limestone within concrete. This is a cost-effective method and uses the flue gas directly.
• Algae cultivation: In this method, captured CO2 is allowed to absorp by microalgae that generates products like proteins, fertilizers, biomass, etc This is one of the competitive source of biofuels.

External Links

• Carbon Capture in the Steel Industry: Opportunities and Challenges | Primetals Technologies