Decarbonization of the Iron and Steel Industry with Direct Reduction of Iron Ore with Green Hydrogen

Abstract

Production of iron and steel releases seven percent of the global greenhouse gas (GHG) emissions. Incremental changes in present primary steel production technologies would not be sufficient to meet the emission reduction targets. Replacing coke, used in the blast furnaces as a reducing agent, with hydrogen produced from water electrolysis has the potential to reduce emissions from iron and steel production substantially. Mass and energy flow model based on an open-source software (Python) has been developed in this work to explore the feasibility of using hydrogen direct reduction of iron ore (HDRI) coupled with electric arc furnace (EAF) for carbon-free steel production. Modeling results show that HDRI-EAF technology could reduce specific emissions from steel production in the EU by more than 35%, at present grid emission levels (295 kgCO 2 /MWh). The energy consumption for 1 ton of liquid steel (tls) production through the HDRI-EAF route was found to be 3.72 MWh, which is slightly more than the 3.48 MWh required for steel production through the blast furnace (BF) basic oxygen furnace route (BOF). Pellet making and steel finishing processes have not been considered. Sensitivity analysis revealed that electrolyzer efficiency is the most important factor affecting the system energy consumption, while the grid emission factor is strongly correlated with the overall system emissions.Energies 2020, 13, 758 2 of 23 country, on the other hand, has a per capita steel consumption of 66.3 kg. As the standard of living in developing countries increases, demand for steel will grow further. The demand for steel will increase until 2050 [4]. Steel could be produced by reducing iron ore or by recycling steel scrap in an electric arc furnace (EAF). Iron and steel sector releases seven percent of the total CO 2 emission and 16% of the total industrial emission of CO 2 globally [5,6]. Limited availability of scrap and demand for special grades of steel, which can not be produced from steel recycling, would lead to an increased demand for ore based steel production in the future. More than 80% [3] of the ore based steel is produced through the BF-BOF route. The BF-BOF route uses approximately 18 GJ/t of energy supplied from coal [7], and has an emission intensity of approximately 1870 kgCO 2 /tls [4,8] (considering pellet making, steel rolling and finishing steps). Majority of the emissions is released from the blast furnace (61%) and coke making plant (27%) [9].Some of the alternative processes with significantly reduced carbon footprint are BF-BOF with carbon capture and storage (CCS), direct reduction of iron ore (DRI) with CCS, electrowining (electrolysis of iron ore) [10] and green hydrogen-based DRI production. Integration of CCS in steelmaking processes is being explored under the ultra-Low carbon dioxide(CO 2 ) steelmaking (ULCOS) [11,12] project. However, concerns over the safe transport and storage of captured makes CCS options less attractive. Electrowining or molten electrolysis of iron ore is a relatively new technol...

The Role of Green and Blue Hydrogen in the Energy Transition—A Technological and Geopolitical Perspective

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Clean production and utilisation of hydrogen in molten salts

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Thermodynamic Study on Reduction of Iron Oxides by H2 + CO + CH4 + N2 Mixture at 900 °C

“…The gas-based direct reduction iron-making process is a kind of non-blast furnace iron-making process which does not use coke and produces solid iron through gas-solid reaction. It is a rapidly developing iron-making process due to its short technological process, high cleanliness, and low CO 2 emission [1]. The basic composition of a gas-based direct reduction iron-making process can be divided into two parts: the gasification process and reduction process [2][3][4][5][6].…”