The steel industry is one of the most carbon-intensive and difficult to decarbonize industries, accounting for about 7.2% of global carbon emissions. According to the data of China Metallurgical Industry Planning Institute, the carbon emission of the steel industry accounts for about 15% of the country in 2020, which is the largest carbon emission industry among 31 categories of China's manufacturing industry. According to the preliminary draft of the "Steel Industry Carbon Peaking and Carbon Reduction Action Plan" revealed by the Institute of Metallurgical Industry Planning in March 2021, the carbon peaking target of the steel industry is initially set as follows: by 2025, the steel industry will achieve carbon emission peaking; by 2030, the carbon emission of the steel industry will be reduced by 30% compared with the peak. The world's leading steel companies and steel associations have also announced their decarbonization plans, as follows.
Global steel organizations' decarbonization plans
Organization & Projects | Year | Carbon Reduction Targets |
Japan Steel Federation | 2050 | 30% |
Voestalpine | 2050 | 80% |
ThyssenKrupp | 2030 | 30% |
2050 | 100% | |
COOLSTAR | 2050 | 15% |
Dilinger and Saaratahl | 2035 | 40% |
HYBRIT | 2026 | 100% |
POSCO | 2030 | 20% |
2040 | 50% | |
2050 | 100% | |
CISA | 2030 | 30% |
2050 | 100% |
According to a study by ThyssenKrupp in Germany, theoretically, smelting 1 ton of iron requires the consumption of 414 kg of carbon, which is equivalent to the emission of about 1.5 t. In fact, due to the limitations of industrial conditions and the consumption of raw materials and electricity in the smelting process, even after deducting the secondary energy consumption of recycling, the carbon emission of producing 1 ton of iron is about 1.9 tons, accounting for about 90% of the total carbon emission of steelmaking.
Although the steel industry is continuously exploring technologies such as thermal storage combustion technology, blast furnace pulverized coal injection technology, blast furnace gas residual pressure power generation technology, blast furnace gas combined cycle power generation technology, dry coke quenching technology, converter negative energy steelmaking technology, etc. to promote the overall process energy saving and emission reduction, the actual application of these technologies has limited emission reduction capacity. Hydrogen metallurgy, with its huge potential for emission reduction and deep decarbonization capability, has become the high point that leading steel companies at home and abroad are aiming to achieve.
Hydrogen metallurgy is the only process option in the steel industry with ultra-low carbon emission potential. Specifically, green hydrogen can play a role in the following processes: in the sintering process, hydrogen can be used as a sintering fuel for iron ore to reduce high carbon energy consumption such as coke dust/coal dust; in the pig iron smelting process, hydrogen can be used as a reducing agent to directly reduce iron ore; in the steel cold rolling annealing process, hydrogen is needed as a protective gas. Since the pig iron smelting process contributes 73.6% of the total carbon emission of the whole process of steel production, the participation of hydrogen as a reducing agent in pig iron smelting is the main research direction of hydrogen metallurgy at present.
Since 2021, China has issued several policy documents aiming to encourage enterprises to develop low-carbon metallurgical technologies such as hydrogen metallurgy, and the documents mainly include.
Policies related to hydrogen metallurgy in China
Release Time | Policy | Main content |
2021.3 | Preliminary Draft of the Action Plan for Carbon Peaking and Carbon Reduction in the Steel Industry | Application of breakthrough low carbon technologies. Mainly hydrogen smelting, oxygen blast furnace and non-blast furnace smelting, carbon capture, utilization and sequestration technologies |
2021.4 | Implementation Measures for Capacity Exchange in the Steel Industry | Conventional iron and steelmaking capacity shall be replaced with a corresponding ratio (1.5:1 ~ 1.1:1) of reduced capacity in accordance with the policy. If the original production capacity is replaced by hydrogen metallurgy technology, the same amount of replacement can be implemented |
2021.12 | The Fourteenth Five-Year Plan for the Development of Raw Materials Industry | Carry out low-carbon manufacturing pilot projects, such as hydrogen-rich carbon cycle blast furnace, hydrogen energy kiln, hydrogen-based direct reduction and other technologies |
There are currently three main global hydrogen metallurgy technology routes, corresponding to the three traditional ironmaking technology routes, where hydrogen can replace the raw materials coke, natural gas and coal reduction of iron ore, respectively, as shown in the table below. Hydrogen metallurgy engineering research started with the development of direct and molten reduction technologies, mainly including hydrogen-rich reduction and all-hydrogen reduction. Since all-hydrogen reduction is limited by the technology and cost of large-scale hydrogen production, hydrogen-rich high-temperature molten state reduction has been prioritized, and controlling the hydrogen-rich content of the reduction gas is the technical key. The production process of hydrogen-rich gas reduction of iron ore has been gradually industrialized since the middle of last century, such as Midrex process and HLY-III process using natural gas.
Hydrogen metallurgy technology route
Technology Route | Schematic | Main Technologies | Technical Notes | Advantages | Limitations |
Hydrogen-rich ironmaking in blast furnaces |
| - | Injection of hydrogen-rich gas in a conventional blast furnace ironmaking plant | Low cost of equipment transformation, with economic, with increased production effect | Limited theoretical reduction potential, technically difficult to achieve all-hydrogen metallurgy |
Gas-based shaft furnace direct reduction ironmaking |
| HYBRIT, Energiron | Direct reduction of iron making using reducing gas, the proportion of hydrogen directly boosted in the reducing gas | High theoretical abatement potential, up to 90% or more | High conversion difficulty, high iron ore raw material quality requirements, insufficient equipment process level |
Hydrogen fusion reduction of iron |
| CISP, SuSteel | Injection of hydrogen-containing gas in the molten reduction ironmaking process |
The main hydrogen metallurgy projects in China are listed below.
Typical hydrogen metallurgy projects in China
Projects | Enterprise | Start-up time | Hydrogen Source |
Blast furnace hydrogen-rich reduction low carbon ironmaking | Bayi Iron & Steel | 2017 | Coke oven gas |
Low carbon hydrogen-rich ironmaking technology transformation project | Xingtai Iron & Steel | 2020 | Furnace top gas |
2000 cubic meter blast furnace scale up hydrogen injection project | JInnan Steel | 2020 | Coal to ethylene glycol by-product hydrogen |
Hydrogen-based direct reduction project with an annual capacity of 300,000 tons of direct reduced iron | TaiHang Mining | 2013 | Coke oven gas |
Gas-based shaft furnace direct reduction ironmaking project with an annual capacity of 1.1 million tons of pig iron | Mintal Group | 2019 | Coal to gas |
Coal-based Hydrogen Metallurgy Project | JISCO | 2019 | Coal to gas |
Direct iron reduction hydrogen-rich gas-based shaft furnace demonstration project with an annual production capacity of 10,000 tons of pig iron | Huaxin Steel | 2018 | Coke oven gas |
Hydrogen energy development and utilization of engineering demonstration construction projects | HBIS Group | 2020 | Coke oven gas |
1 million tons/year hydrogen-based shaft furnace direct reduction demonstration project | Baowu | 2021 | Natural Gas, Coke oven gas |
Hydrogen-based gas direct reduction ironmaking project with an annual capacity of 500,000 tons of pig iron | Rizhao Steel | 2020 | Hydrogen by-product from vinyl acetate production |
300,000 tons of molten reduction high purity foundry pig iron project | Jianlongsteel | 2019 | Coal gas, coke oven gas |
1 million tons of hydrogen metallurgy direct reduction project | Sichuan Anning Iron and Titanium | 2022 | - |
Our hydrogen metallurgy faces the following challenges.
(1) The overall profitability of China's steel industry is low, and the hydrogen energy industry is difficult to make profit in the short term because of the large investment and long cycle.
(2) China needs to solve many technical problems, such as the proportion of blast furnace blowing hydrogen-rich gas, direct reduction ironmaking technology, high temperature resistant materials for melting furnace, etc.
(3) Steel production facilities generally have a long life span and a low replacement rate. In China, for example, the average life span of its blast furnaces is 13 years, and other related facilities can operate for more than 20 years before decommissioning. The rapid transition may bring a certain degree of stranded asset risk.
(4) The price of green hydrogen is much higher than that of coke, and even if the current hydrogen metallurgy technology reaches an advanced level, hydrogen metallurgy may not be profitable.
(5) There is relatively little policy support for hydrogen metallurgy technology in China.
Although China is relatively late in developing hydrogen metallurgy, it has great potential and even has the leading industrial application in the world in hydrogen melt reduction ironmaking technology. In the future, with the development of China's hydrogen energy industry, key technologies such as hydrogen production, storage and refueling will achieve breakthroughs, and the end-use cost of green hydrogen will drop rapidly, so the best time for China to develop hydrogen metallurgy process on a large scale will come.
