Using wood instead of concrete reduces CO2 emissions. Fotolia.com © Michael Flippo
Swedish steel group SSAB, the country’s top CO2 emitter, foregoes CCS. It opts to replace coal with hydrogen. The cement industry and refineries also show low-CO2 potential soon, and without CCS.
If R&D efforts are successful they may be replicated all over the world, and pay part of the cost for the introduction of hydrogen as transport fuel.
Blast furnaces produce large amount of CO2, since coal is used to reduce iron oxides to iron.
So far, the approach to producing CO2-free steel has been dominated by CCS in combination with improved fuel efficiency, at least in Europe, as manifested in the Ulcos/Hisarna1 project in the Netherlands.
CCS has also dominated the Swedish approach to CO2 reduction in all heavy industry. The Confederation of Swedish Enterprise was very clear about this in May 2015 at a seminar about carbon cuts2. Nothing was, however, mentioned about costs and who is supposed to pay.
Swedish steel group SSAB, the country’s top CO2 emitter, foregoes CCS. It opts to replace coal with hydrogen.
But in April 2016, SSAB announced3 that they together with miner LKAB and power producer Vattenfall were launching an R&D effort to use hydrogen as a reductant, hoping to achieve zero carbon, and using direct reduction or iron sponge technology.
Hydrogen is a very clean fuel and can be zero carbon if produced by electrolysis from zero-carbon electricity. This is technically possible anywhere in the world. In Sweden, the prospect of very low carbon power is not that distant.
Electricity in Sweden is produced mainly from hydro, nuclear, wind and biomass. So the CO2 emissions are low now, and can stay low when nuclear power is phased out. Vattenfall, SSAB and LKAB expect it to be replaced with more renewables.
SSAB emitted 21 per cent of Sweden’s ETS emissions in 2015. Another three per cent came from LKAB mining, mainly from sintering/pelleting of iron ore.
Neither company has elaborated, but an obvious factor is that SSAB and LKAB believe that after Paris, “coal forever” is no longer an option, while CCS is not making much headway. Another factor is that power prices are low and are expected to stay low.
With an increasing share of renewables, power prices are expected to fluctuate more: higher when there is little wind and lower when it is windy. In Germany and Denmark there are sometimes even negative prices, which is not viable.
This is a problem hydrogen/iron can actually help to solve. With some flexibility in either iron production or some storage of hydrogen, use of electricity at peak price can be avoided for perhaps several hundreds of hours per year. This would lower its cost considerably, for a small loss in production.
That way SSAB and LKAB would act as virtual power plants, so real peak power plants will not be needed even with much more wind power.
The time perspective4 is early 2030s, i.e. 15–18 years.
This is at least as fast as CCS. According to the IEA, as of 2013, CCS for huge blast furnaces “will not be available before 2030–40”5.
Both technology choices involve technical and economic risks, and the demonstration phase needs public support. But hydrogen solves the CO2 problem for good.
Even if CCS could operate earlier than hydrogen it would involve huge costs being written off over just a few years. To go for both would mean paying twice.
One reason why hydrogen may be faster is that blast furnaces have to be made very large to make economic sense. Direct reduction iron plants exist today, with natural gas as fuel. They can be made smaller and also more flexible to operate.
Blast furnaces also have to run continuously, so carbon capture must not stop them at any time. This calls for very careful planning, tight schedules for installing the huge parts, and clarification of all the legal details regarding responsibilities, guarantees, indemnification etc., or the plant owner cannot take the risk.
Sweden has the wrong geology for CO2 storage, so long pipelines to Norway or the Baltic Sea may have to be built from the two furnaces, which are 1,000 km apart.
Another huge global problem, for which CCS has been touted as the only solution, is cement production. But other ways to reduce emissions have recently appeared, again in Sweden.
CO2 is released when quicklime (CaO) is produced from limestone (CaCO3), and accounted for almost six per cent of global CO2 emissions6 in 2013. On top of that fossil fuels are used for heating the lime in kilns.
Riksbyggen is a cooperative developer and manager of apartment blocks. The company has set a number of green requirements for an apartment block to be built in Gothenburg soon, and claims to be able to reduce the carbon footprint for the concrete framework by 30–35 per cent compared to standard concrete. They are doing so in cooperation with Cementa (part of Heidelberg Cement), mainly by changing the recipe for the cement, by decreasing the share of quicklime and increasing the share of fly ash.
Another Swedish company, Thomas Concrete Group, has started marketing products with 30 per cent fly ash, as a substitute for Portland cement.
Fly ash is produced in large quantities at coal power stations, also from biopower. So far much of it has been used as landfill, which is becoming more difficult in countries such as the US and India. There are also huge amounts of similar ash of volcanic origin. Another cement substitute is slag from steel production. Neither emits CO2.
In Sweden, wood is often used as an alternative to concrete, sometimes combined with magnesium oxide, for example in making boards.
If construction companies demand greener building materials and methods, as they sometimes7 do, they can start a chain reaction in the market. Low environmental impact is an important competitive factor, as many customers want their buildings to be certified as LEED Platinum or Gold, where low-CO2 concrete can earn points8.
There is a discernible market dynamic, perhaps even without government intervention, but certainly with it.
Refineries are also big point sources of CO2. These emissions can be tackled in at least three other ways than CCS. A higher share of biofuels means less emissions from vehicles and from refineries. This has happened in Sweden to some extent, especially for diesel-from-wood.
Hydrogen is used in large quantities in refineries, but is now of fossil origin. The biggest refiner in Sweden, Preem, is investigating the production of “green hydrogen”9.
Finally, if electric cars and hydrogen cars, and biofuels such as methane, ethanol, and methanol take more market share, oil refineries can be phased out.
2 www.svensktnaringsliv.se/fragor/miljo-energi-klimat/basindustrin-siktar-... (in Swedish)
9 https://preem.se/framtiden (in Swedish)