A General Vision for Reduction of Energy Consumption and CO2 Emissions from the Steel Industry

Abstract

The 2018 IPCC (The Intergovernmental Panel on Climate Change’s) report defined the goal to limit global warming to 1.5 °C by 2050. This will require “rapid and far-reaching transitions in land, energy, industry, buildings, transport, and cities”. The challenge falls on all sectors, especially energy production and industry. In this regard, the recent progress and future challenges of greenhouse gas emissions and energy supply are first briefly introduced. Then, the current situation of the steel industry is presented. Steel production is predicted to grow by 25–30% by 2050. The dominant iron-making route, blast furnace (BF), especially, is an energy-intensive process based on fossil fuel consumption; the steel sector is thus responsible for about 7% of all anthropogenic CO2 emissions. In order to take up the 2050 challenge, emissions should see significant cuts. Correspondingly, specific emissions (t CO2/t steel) should be radically decreased. Several large research programs in big steelmaking countries and the EU have been carried out over the last 10–15 years or are ongoing. All plausible measures to decrease CO2 emissions were explored here based on the published literature. The essential results are discussed and concluded. The specific emissions of “world steel” are currently at 1.8 t CO2/t steel. Improved energy efficiency by modernizing plants and adopting best available technologies in all process stages could decrease the emissions by 15–20%. Further reductions towards 1.0 t CO2/t steel level are achievable via novel technologies like top gas recycling in BF, oxygen BF, and maximal replacement of coke by biomass. These processes are, however, waiting for substantive industrialization. Generally, substituting hydrogen for carbon in reductants and fuels like natural gas and coke gas can decrease CO2 emissions remarkably. The same holds for direct reduction processes (DR), which have spread recently, exceeding 100 Mt annual capacity. More radical cut is possible via CO2 capture and storage (CCS). The technology is well-known in the oil industry; and potential applications in other sectors, including the steel industry, are being explored. While this might be a real solution in propitious circumstances, it is hardly universally applicable in the long run. More auspicious is the concept that aims at utilizing captured carbon in the production of chemicals, food, or fuels e.g., methanol (CCU, CCUS). The basic idea is smart, but in the early phase of its application, the high energy-consumption and costs are disincentives. The potential of hydrogen as a fuel and reductant is well-known, but it has a supporting role in iron metallurgy. In the current fight against climate warming, H2 has come into the “limelight” as a reductant, fuel, and energy storage. The hydrogen economy concept contains both production, storage, distribution, and uses. In ironmaking, several research programs have been launched for hydrogen production and reduction of iron oxides. Another global trend is the transfer from fossil fuel to electricity. “Green” electricity generation and hydrogen will be firmly linked together. The electrification of steel production is emphasized upon in this paper as the recycled scrap is estimated to grow from the 30% level to 50% by 2050. Finally, in this review, all means to reduce specific CO2 emissions have been summarized. By thorough modernization of production facilities and energy systems and by adopting new pioneering methods, “world steel” could reach the level of 0.4–0.5 t CO2/t steel and thus reduce two-thirds of current annual emissions.

Application of Liquid Hydrogen Carriers in Hydrogen Steelmaking

“…The world's first, and, to date, only, H-DR plant went into operation in 1998 in Point Lisas, Trinidad; however, that plant closed down in 2016 due to poor economic performance [5,15]. In recent years, interest in H 2 steelmaking is growing, with several industrial projects pursuing H-DR, including HYBRIT (SSAB, LKAB and Vattenfall, Sweden), H2FUTURE (voestalpine, Austria), and SALCOS (Salzgitter, Germany) [16,17]. In addition, both ArcelorMittal and thyssenkrupp are planning to implement H-DR at their Hamburg and Duisburg sites, respectively [18][19][20].…”

Analysis of the Influence of Biomass Addition in Coal Mixture for Metallurgical Coke Production

“…teelmaking processes have a high-energy consumption and coal is the main source, and steel production has been responsible for 7-9% of CO 2 emissions in recent years, largely due to the use of fossil fuels. To produce 1.85 t of steelis emitted around 3.3 t of CO 2 , which puts the steel sector in the spotlight of the environmental discussion (Holappa, 2020).…”

An Economic Model to Assess Profitable Scenarios of EAF-Based Steelmaking Plants under Uncertain Conditions

“…Therefore, to counter this alarming trend, 2 • C was set at the 2015 COP 21/CMP 11 Conference of the United Nations as the allowed limit for global warming by 2050; then, it was lowered to 1.5 • C at the COP 24 meeting in 2018. To meet these limits, it would be necessary to reduce current emissions by 80% by 2050 [2]. Consistently, policies have been adopted at the European level to counter climate change and transform the EU into an energy-efficient and low-carbon economy.…”

“…It is estimated that for 2018, emissions from global steel production represented 7-9% of direct emissions generated by the use of fossil fuels, with a specific emissions value of 1.8 tCO2/t steel [9]. As can be observed in Figure 1, global steel production is expected to grow up to 2500 Mt/y by 2050, which would entail, following the current production process, the generation of 4500 tCO2/y, which is a value that is not consistent with the achievement of the aforementioned objectives [2]. The main steel production process is represented by the so-called primary steel production route or integrated steel production route.…”