How iron and steel emissions can be cut
The huge emissions from the steel industry can be virtually eliminated by using hydrogen from green power, or from other electric processes. CCS is not used, not needed and not likely to be a mitigation option.
The main climate issue for iron- and steel-making is the CO₂ emissions from the use of coke and coal to reduce ore (iron oxide) to elemental iron in blast furnaces. For every atom of iron product, about 1.5 molecules of CO₂ are emitted. Every ton of steel produced in 2018 emitted on average 1.85 tons of carbon dioxide, equating to about 8 per cent of global carbon dioxide emissions.
The steel industry generates between 7 and 9 per cent of direct emissions from the global use of fossil fuel, according to worldsteel.org. The competing, but much less widely used technology is Direct Reduced Iron, which usually uses (fossil) natural gas as the reducing agent, and which then also emits smaller but still considerable amounts of CO₂. Fossil fuels are also used for heating the steel before rolling it. Electric arc furnaces have indirect CO₂ emissions, depending on the source of electricity, and often also have direct emissions from the fossil fuels used to assist the melt. The Swedish Hybrit project was launched in 2016 to replace coal with hydrogen in steel production.
It was the first of its kind. Now, many of biggest steel companies in the world are heading in more or less the same direction. Just a few years ago the climate strategy of the global steel industry specifically or heavy industry in general could be summarised in three letters: CCS. Or rather in six letters “Say CCS”, as nothing much actually happened. After almost 20 years of hype, no CO₂ has been captured anywhere in the world from the production of steel, cement, glass, aluminium or paper pulp, and very little from power plants. The big EU ULCOS project (ultra-lowCO₂ steel-making), which began in 2004, eventually sank without a trace. Its main message was to keep blast furnaces, keep coal and coke, but add CCS.
Only months after the Paris climate agreement, in April 2016, Swedish steelmaker SSAB, iron ore miner LKAB and power producer Vattenfall launched a new decarbonisation strategy: to produce hydrogen with renewables and use the hydrogen to reduce iron oxide ore pellets to sponge iron. This was a bolt out of the blue, a radical departure from the previous strategy. Four years later, McKinsey found a very different situation: “All major European steel players are currently building or already testing hydrogen-based steel production processes, either using hydrogen as a PCI replacement or using hydrogen-based direct reduction.” ArcelorMittal is the second-biggest steel producer in the world.
It does the same thing as SSAB and is also trying another very different no-carbon tech. The company states that it is “exploring iron ore reduction technologies using hydrogen and electrolysis, both of which could deliver significant carbon reductions if powered with clean electricity. In March 2019, we launched a €65 million pilot project in Hamburg, Germany to test hydrogen steel-making on an industrial scale, with an annual production of 100,000 tonnes of steel. At the same time, we have been exploring direct iron ore reduction using electrolysis for a number of years. We lead the EU-funded Siderwin project, which is now constructing an industrial cell to pilot the technology.”
The company aims to have the Hamburg plant operating in 2025, which is one year before SSAB and LKAB also aim to have their (ten times bigger) hydrogen steel demo plant operating. The Siderwin technology dissolves the ore, for example iron-rich residues from bauxite. It works at low temperature (110 degrees C) and is expected to reach industrial scale by 2030. If it achieves this it will still rely on green electricity. Chinese Baowu, now the world’s largest steel producer, has a hydrogen partnership with Linde, a global industrial gases company, “with the aim of beating the Swedish steel maker SSAB to commercialising clean steel production”, according to an article in the Australian Financial Review, which considers this as potentially bad news for exports of Australian coking coal.
The coming competitivity of hydrogen, and the shrinking market for coking coal, was also recently pointed out by a Friends of the Earth report on a possible new coal mine in Cumbria, England. According to its energy campaigner, Tony Bosworth: “The UK steel industry will only buy a small percentage of the Cumbrian coal, and with European steelmakers already moving to greener steel production, the market for this mine is declining before it has even opened.” The third biggest steel producer, NSSMC (Nippon Steel), is also working with hydrogen (as well as CCS) and also boasts a new steel for hydrogen infrastructure. It is too early to say “problem solved” for CO₂ from steelmaking, but it surely looks as if green electricity and green hydrogen can do the job, whereas CCS is going nowhere.
Hydrogen is getting much more attention for reasons aside from steel production, such as short-term and long-term (seasonal) storage to balance wind and solar, or for ships, trucks and buses. The implication is that hydrogen will be produced by electrolysis using renewable electricity, abundant and cheap wind and solar. Hydrogen will be green. Future power is increasingly synonymous with solar and wind.
(A longer more detailed article with references will be published in a report by AirClim soon)