Low-carbon production of iron and steel: Technology options, economic assessment, and policy

Abstract

This paper explores existing approaches and potential decarbonization paths of the global iron and steel industry: fuel switching to low-C hydrogen, solid biomass, zero-carbon electricity substitution, and retrofit with carbon capture and storage (CCS). Achieving net-zero primary production with current available technologies faces many challenges from plant design fundamentals (BF or DRI), resource availability, carbon footprint uncertainty, and cost. Long-term opportunities to reach net-zero require asset replacement, combining approaches, or both. Short-term opportunities lie in CCS retrofit and fuel substitution, particularly blue hydrogen, carbon-neutral biomass, and zero-carbon electricity but only provide low or partial GHG reductions. For individual plants, the optimal local solution depends on geography, natural resources, infrastructure, and economies. Large-scale deployment is limited by resource availability, infrastructure, and policy incentives. Given increased urgency to transition the global economy to net-zero CO2 emission, governments and industry have increased focus on decarbonizing hard-to-abate sectors, including steel making, which contributes roughly 6% of global CO2 emission and 8% of energy-related emission (including power consumption emission). This paper reviews current global iron and steel production and assesses available decarbonization technologies, including hydrogen injection, solid biomass substitution, zero-C electricity substitution, carbon capture and storage (CCS) retrofit, and combinations of these decarbonization approaches. Blast furnace-basic oxygen furnace (BF-BOF) dominates production (71%) and is particularly stubborn to any decarbonization technology. Direct reduced iron to electric arc furnace (DRI-EAF) production is 5% and growing, it appears to have better decarbonization potential to move toward net-zero. Secondary steel production using mainly steel scrap in electric arc furnace (EAF-scrap) is 24% of global production and has both the lowest energy consumption and is technically simplest to decarbonize through electrification but is limited in market share to recycled steel capacity. Of the options assessed, blue hydrogen, carbon neutral biomass, and CCS appear to have the lowest cost and highest technical maturity. However, no single approach today can deliver deep decarbonization to the iron and steel industry and all approaches lead to substantial production cost increase. No uniform ideal solution exists, and different geographies, infrastructure, and economies will determine the local optimum solution with viability and cost. Policy measures will be required to provide financial incentives for decarbonization and to avoid unwelcome outcomes such as emissions leakage or job loss. Given increased urgency to transition the global economy to net-zero CO2 emission, governments and industry have increased focus on decarbonizing hard-to-abate sectors, including steel making, which contributes roughly 6% of global CO2 emission and 8% of energy-related emission (including power consumption emission). This paper reviews current global iron and steel production and assesses available decarbonization technologies, including hydrogen injection, solid biomass substitution, zero-C electricity substitution, carbon capture and storage (CCS) retrofit, and combinations of these decarbonization approaches. Blast furnace-basic oxygen furnace (BF-BOF) dominates production (71%) and is particularly stubborn to any decarbonization technology. Direct reduced iron to electric arc furnace (DRI-EAF) production is 5% and growing, it appears to have better decarbonization potential to move toward net-zero. Secondary steel production using mainly steel scrap in electric arc furnace (EAF-scrap) is 24% of global production and has both the lowest energy consumption and is technically simplest to decarbonize through electrification but is limited in market share to recycled steel capacity. Of the options assessed, blue hydrogen, carbon neutral biomass, and CCS appear to have the lowest cost and highest technical maturity. However, no single approach today can deliver deep decarbonization to the iron and steel industry and all approaches lead to substantial production cost increase. No uniform ideal solution exists, and different geographies, infrastructure, and economies will determine the local optimum solution with viability and cost. Policy measures will be required to provide financial incentives for decarbonization and to avoid unwelcome outcomes such as emissions leakage or job loss. A core challenge in the energy transition and deep decarbonization is the growing demand for primary energy services. It is widely understood that man-made climate change is chiefly caused by greenhouse gas emissions, especially carbon dioxide (CO2), and that the consequences of global warming will be profound, widespread, and destructive.1IPCCSummary for Policymakers.in: Masson-Delmotte V. Zhai P. Pörtner H.-O. Roberts D. Skea J. Shukla P.R. Pirani A. Moufouma-Okia W. Péan C. Pidcock R. Connors S. Matthews J.B.R. Chen Y. Zhou X. Gomis M.I. Lonnoy E. Maycock T. Tignor M. Waterfield T. Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. World Meteorological Organization, 2018: 32Google Scholar Nonetheless, global emissions have risen more or less continuously for the past 25 years and have increased each of the last 3 years.2United Nations Environment ProgrammeEmissions Gap Report 2019.https://www.unenvironment.org/resources/emissions-gap-report-2019Date: 2019Google Scholar This is chiefly due to the growing demand of energy and of products that require energy for their production. Nowhere is this challenge more evident than in the industrial sector, which has grown profoundly and rapidly over the last 20 years.3International Energy AgencyData and Statistics, CO2 emissions by sector.https://www.iea.org/data-and-statistics?country=WORLD&fuel=CO2%20emissions&indicator=CO2BySectorDate: 2020Google Scholar Steel, a major sector from a commercial and emissions standpoint, is an essential material for the modern world and is a key component of many national economies (Figure 1). It is used in construction, military and defense, and manufacturing (e.g., automobiles). A globally traded commodity, iron and steel production has tripled production since 2000, and 2018 saw $2.5 trillion in sales.4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar It is also an enormous source of greenhouse gases: today’s dominant production pathway BF-BOF is very carbon intensive (see Table 1), whereas the iron and steel industry generates roughly 6% of global CO2 emissions (see Table 2). From a technical perspective, the challenge of decarbonization involves two processes: chemical reduction for iron ore refining (process emission), commonly with metallurgical coal and coke, and from the high-temperature heat sourced needed to operate blast furnace (BF) and other production reactor.5Friedmann J. Fan Z. Tang K. Low-Carbon Heat Solutions for Heavy Industry: Sources, Options, and Costs Today. Center on Global Energy Policy, 2019https://www.energypolicy.columbia.edu/research/report/low-carbon-heat-solutions-heavy-industry-sources-options-and-costs-todayGoogle Scholar Unlike the power sector, there are relatively few technical options to manage these challenges. From a non-technical perspective, challenges include the globally traded nature of the commodity, national dependencies for both security and economic well-being, the small margins of most producers, and labor politics.6Sandalow D. Friedmann J. Aines R. McCormick C. McCoy S. Stolaroff J. ICEF Industrial Heat Decarbonization Roadmap. ICEF, 2019https://www.icef-forum.org/roadmap/Google Scholar Moreover, operating assets have long capital lives and are expected to operate for many decades, limiting the rate and range of options to substitute for existing facilities and thereby reduce emissions.7Friedmann J. “Congressional Testimony, House Energy and Commerce Committee, Hearing on Industrial Decarbonization.” CGEP, SIPA. Columbia University, 2019Google Scholar This paper examines near-term options to rapidly reduce greenhouse gas (GHG) emissions in steel production and seeks to identify and explain near-term pathways to reduce GHG emissions of steel hot metal (HM). We examine technical options in terms of cost, viability, readiness, and ability to scale. In addition, we assess key aspects of current commercial markets and potential policy options to accelerate a transition to low-emissions production of steel. World crude steel production exceeded 1,808 million tons in 2018 and had a 4.5% growth compared with the 2017 level.4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar Three dominant production processes contributed to 99.6% of steel HM production (Figure 2) as follows:1.Blast furnace-basic oxygen furnace (BF-BOF): This is the dominant steel production route in the iron and steel industry, involving the reduction of iron ore to pig iron in the blast furnace. BF-BOF operation relies almost entirely on coal products, emitting ∼70% of CO2 in the integrated plant (BF iron making). Hot iron is then charged to a basic oxygen furnace (BOF) to make steel HM (BOF steel making). An integrated BF-BOF production plant also includes process plants for coking, pelletizing, sinter, finishing, and associated power production.2.Electric arc furnace (EAF): this steel making process using electric arc to heat charged materials such as pig iron, steel scraps, and direct reduced iron (DRI) product (also referred as sponge iron) with electricity as the only energy source. Today, EAF is the dominant approach for steel recycling (i.e., secondary steel production) and also contributes to primary steel production by upgrading or refining DRI sponge iron. EAF steel production operates in batch mode instead of continuous like a BF-BOF plant.3.DRI: This iron production process directly reduces iron ore in solid-state with the reaction temperature below the melting point of iron. Reducing gases are produced from natural gas (gas-based DRI) or coal (coal-based DRI) called syngas, a mixture of H2 and CO. Although DRI production is more energy efficient than pig iron production from BF, additional processing (typically EAF) is needed to upgrade DRI sponge iron for market.These processes operate with different feedstocks. The BF-BOF pathway converts raw iron ore to pig iron and then to steel HM, whereas EAF converts both steel scrap and sponge iron to steel HM. DRI converts raw iron ore to sponge iron, a porous, permeable, and highly reactive product that requires treatment with EAF before selling to market. One of the well-known hard-to-abate sectors, substantial iron and steel industry decarbonization will increase production cost significantly (> $120 per ton).8Energy Transitions CommissionMission Possible: Reaching net-zero carbon emissions from harder-to-abate sectors.https://www.energy-transitions.org/publications/mission-possible/Date: 2018Google Scholar The core issue of decarbonizing it is not lack of technological solutions but that these solutions carry high abatement costs, which directly affects market share, trade, and labor. This study focuses on the full process decarbonization of steel making, including the three primary or secondary processes discussed above and any necessary pre-treatments (such as sintering and coking in BF-BOF production) to produce HM (not including post treatment such as finishing and alloying). Specific integrated decarbonization methods that recover part of the energy input (e.g., quench gas reusing, top gas recycling, waste heat for carbon capture and storage (CCS), or H2 production) are discussed on a case basis. The BF-BOF route employs BF to reduce the iron ore to molten iron and subsequently refined to steel in a BOF. As the dominant technology for primary steelmaking, BF-BOF route produced 71% of global crude steel production, over 1,279 million tons in 2018.4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar Integrated BF-BOF operations (Figure 3) include pelleting, sintering, coking, and iron making (in BF) plus steelmaking (in BOF). This study covers the integrated route carbon emission and energy consumption, and assumptions are listed in Table 1.Table 1CO2 emission using integrated route BF-BOF technologyProcessEmission (kg-CO2 per ton-HM)aThe U.S. average electricity carbon intensity case: CO2 460 kg/MWhEmission (kg-CO2 per ton-HM)bThe zero-C electricity caseBF1,5141,476coke production10197sintering276260pelletizing4635BOF steelmaking229193total2,225c2016 global weighted average for the top fifteen steel production countries is 2238 kg/ton crude steel HM, covering > 85% global steel production from BF-BOF.102,061See Orth et al.9Orth A. Anastasijevic N. Eichberger H. Low CO2 emission technologies for iron and steelmaking as well as titania slag production.Miner. Eng. 2007; 20: 854-861Crossref Scopus (67) Google Scholara The U.S. average electricity carbon intensity case: CO2 460 kg/MWhb The zero-C electricity casec 2016 global weighted average for the top fifteen steel production countries is 2238 kg/ton crude steel HM, covering > 85% global steel production from BF-BOF.10Hasanbeigi A. Springer C. How clean if the U.S. steel industry? An international benchmarking of energy and CO2 intensities. Global Efficiency Intelligence, 2019https://www.greengrowthknowledge.org/research/how-clean-us-steel-industryGoogle Scholar Open table in a new tab See Orth et al.9Orth A. Anastasijevic N. Eichberger H. Low CO2 emission technologies for iron and steelmaking as well as titania slag production.Miner. Eng. 2007; 20: 854-861Crossref Scopus (67) Google Scholar The single biggest contributor to integrated BF-BOF steeling making CO2 emission is mainly driven by the requirement of carbon, usually coke, as the reductant. The potential to further minimize CO2 emissions with equipment upgrades and operation optimization is limited.11Cameron I. Sukhram M. Lefebvre K. Davenport W. Blast Furnace Ironmaking Analysis, Control, and Optimization.in: Blast Furnace Ironmaking Analysis, Control, and Optimization. 2019: 453-459Google Scholar This study targets low-carbon heat and low-carbon reductant for BF specifically, such as H2 and biomass-based material. Other assumptions that might be applied include the following: (1) zero-C electricity supply, (2) ore fines to avoid agglomeration, (3) fine coal to avoid coking. Combining these approaches could eliminate CO2 emission from coking, sintering, and pelletizing completely, yielding in maximumly 20% CO2 decrease for a facility. EAF is the most common way of producing secondary (recycled) steel from steel scrap feedstocks. EAF contributes ∼24% of global steel production, over 430 million tons (Mt) in 2018.4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar It is the major steel production method for North American Free Trade Agreement (NAFTA) countries (59%), and the European Union (EU) (41%).4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar As the most important electrification opportunity in the steelmaking industry, EAF production is intrinsically low-carbon compared with the integrated BF-BOF route and is easiest to modify. Studies show that the carbon footprint per ton of EAF steel can be as low as 0.23∼0.46 ton CO2 depending on iron type (pig iron or scrap), electricity sources, and efficiencies. This would be only 10%∼20% of conventional BF-BOF operations.12Kirschen M. Badr K. Pfeifer H. Influence of direct reduced iron on the energy balance of the electric arc furnace in steel industry.Energy. 2011; 36: 6146-6155Crossref Scopus (85) Google Scholar A typical EAF facility has about 1 Mt steel production capacity in comparing with a typical 3 Mt or large capacity of integrated BF-BOF mill,13U.S. Department of Energy.Energy and Environmental Profile of the U.S. Iron and Steel Industry. U.S. Department of Energy Office of Industrial Technologies, 2000https://www.energy.gov/sites/prod/files/2013/11/f4/steel_profile.pdfGoogle Scholar requiring less up-front capital to invest in modifications. Limitations prevent EAF from playing a larger role in decarbonizing the whole steelmaking industry. First and foremost, EAF takes recycled steel scraps as feedstocks and is therefore subject to supply limitation. Second, batch operation yields intermittent and discontinuous duty cycles, causing power quality problems for transmission and generation.14Seker M. Memmedov A. Huseyinov R. Kockanat S. Power Quality Measurement and Analysis in Electric Arc Furnace for Turkish Electricity Transmission System.Elektron. Elektrotech. 2017; 23: 25-33Crossref Scopus (2) Google Scholar Both limitations prevent EAF from easy penetration deeper into the global steelmaking profile. In contrast, the higher penetration of intermittent renewables power generation might lead to increased market share and use. EAF also consumes the products of DRI, also referred as sponge iron. DRI is as pure as pig iron and is an ideal feedstock to EAF efficiency gains. As a feedstock, EAF can take any fraction of sponge iron (from 0% to 100%). The DRI-EAF combination allows for higher electrification and lower emission if low-carbon feedstocks and electricity are used. The production of steel from the DRI-EAF route exceeded 90 million tons in 2018 (5% global production),4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar with DRI sponge iron production over 100 million tons.15Midrex2018 World Direct Reduction Statistics.https://www.midrex.com/wp-content/uploads/Midrex_STATSbookprint_2018Final-1.pdfDate: 2019Google Scholar India (coal feedstock) and Iran (gas feedstock) are the leading countries in producing DRI. DRI production requires lower temperatures for its direct reduction reaction and is a solid-state process at temperatures below the melting point of iron (1,200°C). Reduction gas (commonly a mixture of H2 and carbon monoxide [CO] syngas) is typically made from either natural gas or coal. Two of the main reduction reactions in the kiln: Fe2O3 + CO and FeO + CO, are still the main sources of CO2. The current DRI-EAF route using natural gas has only 62% the carbon footprint as a traditional integrated BF-BOF route.16European commissionEuropean Steel: The Wind of Change, Brussels Seminar.https://ec.europa.eu/research/index.cfm?eventcode=80BB405C-DA08-56D3-800BC46FC9A6F350&pg=eventsDate: 2018Google Scholar It also has a better deep decarbonization potential, given that the reduction gas is easily replaced with higher H2 mixtures or even full hydrogen,17Midrex H2Midrex H2: helping steelmakers reduce CO2 emissions.https://www.midrex.com/technology/midrex-process/midrex-h2/Date: 2020Google Scholar whereas BF-BOF faces greater difficulty in higher H2 use because of facility retrofit barriers (see the section “hydrogen in BF and DRI” below). Both EAF steelmaking pathways’ flow diagram are shown jointly in Figure 4. The above summaries cover the overwhelming majority of world steel production (> 99%). Multiple novel technologies under development show great potential to replace the dominant steel production pathways in the far future but not yet commercially available. These include the HIsarna smelting ironmaking process and molten oxide electrolysis (MOE), both anticipated to enter pilot plant testing in the short-term future.HIsarna is a direct bath-smelting reduction technology that combines coal pre-heating and partial pyrolysis with the smelting reduction vessel working as its core reaction container.18van der Stel J. Meijer K. Teerhuis C. Zeijlstra C. Keilman G. Ouwehand M. Tata steel.https://ieaghg.org/docs/General_Docs/Iron%20and%20Steel%202%20Secured%20presentations/2_1330%20Jan%20van%20der%20Stel.pdfDate: 2013Google Scholar It can allow non-coking coal and low-cost iron ores (outside BF quality range) to produce iron with 20% less carbon footprint.19Quader A. Ahmed S. Dawal S.Z. Nukman Y. Present needs, recent progress and future trends of energy-efficient Ultra-Low Carbon Dioxide (CO2) Steelmaking (ULCOS) program.Renew. Sustain. Energy Rev. 2016; 55: 537-549Crossref Scopus (82) Google Scholar Commercial level successfulness for this technology is expected in 10–20 years.20Yan J. Progress and Future of Breakthrough Low-carbon Steelmaking Technology (ULCOS) of EU.International Journal of Mineral Processing and Extractive Metallurgy. 2018; 3: 15-22Crossref Google ScholarMOE can allow electricity as the only energy source and reduction agent for steelmaking.21Boston MetalMetal oxide electrolysis.https://www.bostonmetal.com/moe-technology/Date: 2020Google Scholar,22Allanore A. Yin L. Sadoway D.R. A new anode material for oxygen evolution in molten oxide electrolysis.Nature. 2013; 497: 353-356Crossref PubMed Scopus (108) Google Scholar Its carbon footprint is therefore chiefly determined by electricity sources. Although promising, novel processes such as these are outside the scope of this study, which focuses on existing facility decarbonization, and only discussed cursorily. In this study, we use three hypothetic plants to represent the global steelmaking asset base (Table 2): one integrated BF-BOF plant, one EAF plant with steel scrap as feedstock, and one DRI-EAF configuration. The data in Table 2 is representative. We recognize that EAF can take feedstock from DRI sponge iron (e.g., India & Iran), BF pig iron (e.g., China), and steel scraps (most Organization for Economic Co-operation and Development [OECD] countries) and process them together.10Hasanbeigi A. Springer C. How clean if the U.S. steel industry? An international benchmarking of energy and CO2 intensities. Global Efficiency Intelligence, 2019https://www.greengrowthknowledge.org/research/how-clean-us-steel-industryGoogle Scholar Similarly, the DRI carbon footprint will vary if syngas is produced from a coal-based process or gas-based process15Midrex2018 World Direct Reduction Statistics.https://www.midrex.com/wp-content/uploads/Midrex_STATSbookprint_2018Final-1.pdfDate: 2019Google Scholar (also see Table 2). As such, our analyses are representative and inclusive but not comprehensive.Table 2Data input for steel production scenariosProduction methodsBF-BOFEAFDRI-EAFglobal production share (%)71%24%5% (coal-based 1% + gas-based 4%)primary reactors: CCS suitableaIn this paper, CCS applies only on large-point source CO2 emission from the primary production reactors such as BF top-gas and DRI exit gas. (kgCO2 per ton)1,4769Orth A. Anastasijevic N. Eichberger H. Low CO2 emission technologies for iron and steelmaking as well as titania slag production.Miner. Eng. 2007; 20: 854-861Crossref Scopus (67) Google Scholar01,048 (coal-based)522 (gas-based)23Dey N. Prasad A. Singh S. Energy survey of the coal based sponge iron industry,.Case Studies in Thermal Engineering. 2015; 6: 1-15Crossref Scopus (10) Google Scholar,24Holling M. Gellert S. Direct Reduction: Transition from Natural Gas to Hydrogen? Conference: ICSTI 2018.https://www.researchgate.net/publication/327962750_Direct_Reduction_Transition_from_Natural_Gas_to_HydrogenDate: 2018Google Scholarpre-treatment reactors: not CCS suitable (kgCO2 per ton)5859Orth A. Anastasijevic N. Eichberger H. Low CO2 emission technologies for iron and steelmaking as well as titania slag production.Miner. Eng. 2007; 20: 854-861Crossref Scopus (67) Google Scholar42025United States Environmental Protection AgencyAvailable and emerging technologies for reducing greenhouse gas emissions from the iron and steel industry. U.S. Environmental Protection Agency, 2012https://www.epa.gov/sites/production/files/2015-12/documents/ironsteel.pdfGoogle Scholar30726Barati M. Energy intensity and greenhouse gases footprint of metallurgical processes: A continuous steelmaking case study.Energy. 2010; 35: 3731-3737Crossref Scopus (26) Google Scholarelectricity intensity (kWh per ton)35627Hasanbeigi A. Price L. Aden N. Zhang C. Li X. Shangguan F. A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.DOE. 2011; https://www.osti.gov/biblio/1050727Google Scholar91827Hasanbeigi A. Price L. Aden N. Zhang C. Li X. Shangguan F. A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.DOE. 2011; https://www.osti.gov/biblio/1050727Google Scholar380 (coal-based DRI)313 (gas-based DRI)27Hasanbeigi A. Price L. Aden N. Zhang C. Li X. Shangguan F. A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.DOE. 2011; https://www.osti.gov/biblio/1050727Google ScholarDRI-EAF electricity intensity (kWh per ton)N/AN/A91827Hasanbeigi A. Price L. Aden N. Zhang C. Li X. Shangguan F. A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.DOE. 2011; https://www.osti.gov/biblio/1050727Google Scholarelectricity carbon intensity (kg per MWh)46028U.S. Energy Information AdministrationU.S. Energy-Related Carbon Dioxide Emissions, 2018.https://www.eia.gov/environment/emissions/carbon/archive/2018/Date: 2019Google Scholar46028U.S. Energy Information AdministrationU.S. Energy-Related Carbon Dioxide Emissions, 2018.https://www.eia.gov/environment/emissions/carbon/archive/2018/Date: 2019Google Scholar46028U.S. Energy Information AdministrationU.S. Energy-Related Carbon Dioxide Emissions, 2018.https://www.eia.gov/environment/emissions/carbon/archive/2018/Date: 2019Google ScholarHM carbon intensity (kgCO2 per ton)2,2258421953 (coal-based)1395 (gas-based)bConversion of DRI to HM in weight is assumed 90% (2018 data, 100 Mt DRI15 produced 90 Mt HM).4 HM carbon intensity from DRI-EAF include both DRI carbon emission and EAF carbon emission (electricity only)global weighted average (kgCO2 per ton)1,857cOn average for 2017, roughly 1.9 tons of CO2 were emitted for every ton of steel produced, which accounts for approximately 6.7% of global GHG emission.29 These 3 hypothetical models’ weighted average matches the global carbon emission from the iron and steel industry. (electricity emission: 246 kgCO2 per ton-HM, 13.3%)See Dey et al.23Dey N. Prasad A. Singh S. Energy survey of the coal based sponge iron industry,.Case Studies in Thermal Engineering. 2015; 6: 1-15Crossref Scopus (10) Google Scholar, Orth et al.9Orth A. Anastasijevic N. Eichberger H. Low CO2 emission technologies for iron and steelmaking as well as titania slag production.Miner. Eng. 2007; 20: 854-861Crossref Scopus (67) Google Scholar, Holling and Gellert24Holling M. Gellert S. Direct Reduction: Transition from Natural Gas to Hydrogen? Conference: ICSTI 2018.https://www.researchgate.net/publication/327962750_Direct_Reduction_Transition_from_Natural_Gas_to_HydrogenDate: 2018Google Scholar, United States Environmental Protection Agency25United States Environmental Protection AgencyAvailable and emerging technologies for reducing greenhouse gas emissions from the iron and steel industry. U.S. Environmental Protection Agency, 2012https://www.epa.gov/sites/production/files/2015-12/documents/ironsteel.pdfGoogle Scholar, Barati26Barati M. Energy intensity and greenhouse gases footprint of metallurgical processes: A continuous steelmaking case study.Energy. 2010; 35: 3731-3737Crossref Scopus (26) Google Scholar, Hasanbeigi et al.27Hasanbeigi A. Price L. Aden N. Zhang C. Li X. Shangguan F. A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.DOE. 2011; https://www.osti.gov/biblio/1050727Google Scholar, and U.S. Energy Information Administration28U.S. Energy Information AdministrationU.S. Energy-Related Carbon Dioxide Emissions, 2018.https://www.eia.gov/environment/emissions/carbon/archive/2018/Date: 2019Google Scholara In this paper, CCS applies only on large-point source CO2 emission from the primary production reactors such as BF top-gas and DRI exit gas.b Conversion of DRI to HM in weight is assumed 90% (2018 data, 100 Mt DRI15Midrex2018 World Direct Reduction Statistics.https://www.midrex.com/wp-content/uploads/Midrex_STATSbookprint_2018Final-1.pdfDate: 2019Google Scholar produced 90 Mt HM).4Worldsteel AssociationWorld steel in figures 2019.https://www.worldsteel.org/en/dam/jcr:96d7a585-e6b2-4d63-b943-4cd9ab621a91/World%2520Steel%2520in%2520Figures%25202019.pdfDate: 2019Google Scholar HM carbon intensity from DRI-EAF include both DRI carbon emission and EAF carbon emission (electricity only)c On average for 2017, roughly 1.9 tons of CO2 were emitted for every ton of steel produced, which accounts for approximately 6.7% of global GHG emission.29Worldsteel AssociationSteel’s contribution to a low carbon future and climate resilient societies - worldsteel positio