The iron and steel industry is one of the largest industrial emitters of CO2, accounting for between 4% and 7% of anthropogenic CO2 emissions globally. In the past 40 years there has been a 50% reduction in energy consumption in the industry in Europe. This has mainly been due to the increased use of recycled scrap iron from a 20% share in the 1970s to around 40% today, while the manufacture of iron from iron ore has declined. However, a complete shift to recycling is limited by the availability and quality of scrap.
State of the art
There are two main routes to produce steel. The integrated route is based on the production of iron from iron ore, while the recycling route uses scrap iron as the main iron-bearing raw material in electric arc furnaces. In both cases, the energy consumed comes from fuel (mainly coal and coke) and electricity. The recycling route consumes much less energy (about 80%) than the integrated route.
The integrated route – used for about 60% of production globally – relies on the use of coke ovens, sinter plants, blast furnaces (BF) and Basic Oxygen Furnace (BOF) converters. The fuels used are fully exploited, first for their chemical reaction potential (during which they are converted into process gases) and then for their energy potential, by capturing, cleaning and combusting these process gases in production processes and by generating heat and electricity. However, the increased energy efficiency that comes with the re-use of process gases – so-called cascadic fuel use – does not reduce overall energy consumption, in terms of the primary fuels used for the chemical reactions.
Alternatives to the two main production routes include direct-reduced iron technology and smelting reduction (which, like the blast furnace, produces hot metal). The advantage of these technologies compared with the integrated route is that the raw materials do not need to be treated (‘beneficiated’), e.g. by sintering and making coke, and that they can adjust well to low-grade raw materials. On the other hand, more primary fuels are needed, especially natural gas for direct reduced iron technology and coal for smelting reduction.
20-25% savings in CO2 emissions in the smelting reduction process can be achieved if the additional coal is transformed into process gases, which are then captured and used to produce heat and electricity. At present in EU-28, only one plant uses direct-reduced iron technology (in Germany), while none of the eight operational facilities for smelting reduction in the world are in Europe.
TECHNOLOGY OBJECTIVES AND ACTIONS
There is potential for reducing direct CO2 emissions by about 27 Mt per year by applying best practice, including the retro-fitting of existing equipment. This potential however relies strongly on a substitution of local raw materials with increased imports of best performance raw materials from outside the EU (especially ores and coal).
The industry’s flagship ULCOS programme (Ultra–Low Carbon Dioxide (CO2) Steelmaking), supported by the European Commission and involving a consortium of 48 leading players in industry and research, aims to reduce the CO2 emissions of today’s best routes by at least 50%. The first phase of ULCOS had a budget of EUR 75 million.
As a result of the first phase of ULCOS, four main processes have been earmarked for further development. The top gas recycling blast furnace is based on the separation of the off-gases so that the useful components can be recycled back into the furnace and used as a reducing agent. Meanwhile, oxygen is injected into the furnace instead of preheated air to facilitate CO2 capture and storage (CCS). The timeline to complete the demonstration programme is about 10 years, allowing further market roll-out after 2020.
The HIsarna technology combines preheating of coal and partial pyrolysis in a reactor, a melting cyclone for ore melting and a smelter vessel for final ore reduction and iron production. Market roll-out is scheduled for 2030. The ULCORED (advanced Direct Reduction with CCS) involves the direct reduction of iron ore by a reducing gas produced from natural gas. The reduced iron is in a solid state and will need an electric arc furnace to melt the iron. An experimental pilot plant is planned in Sweden, with market roll-out foreseen for 2030. The experimental processes, known as ULCOWIN and ULCOSYS, are electrolysis processes to be tested on a laboratory scale.
In thermal power plants, the development of new steel grades will increase temperature and pressure and will contribute to the improvement of energy efficiency. In advanced supercritical plants with steam conditions up to 600°C and 30 MPa, net efficiencies between 46 and 49% could be reached whereas older pulverised coal plants, with subcritical steam parameters, operate with efficiencies between 32 - 40%. Each percentage point efficiency increase is equivalent to a 2.5% reduction in tonnes of CO2 emitted.
The development of new grades (lightweight alloys) for the automotive industry can decrease steel consumption (energy consumption) and at the same time improve the efficiency of the final products – lighter cars will be more efficient.
The production of crude steel in the EU in 2012 represented about 11% of total world production (1 510 Mt of crude steel), compared to a 24.6% share in 1998. The contraction of the EU’s share in overall world production is largely due to the fact that Chinese production has grown more than fourfold over this period.
The growth of iron and steel production in the EU is estimated at about 1.18% per year up to 2030. The increase in the production would be covered mainly by an increase in the recycling route. Production from the integrated route is expected to stay around its current values.
Further increases in the recycling rate beyond the 60% in 2030 will be hampered by the availability of scrap. Such high recycling rates will increase the impurities and reduce overall steel quality. Recycling is associated with high emissions of heavy metals and organic pollutants due to the impurities of scrap.
Meanwhile, the thermochemical efficiency of current blast furnaces is almost optimal. As CO2 emissions are linked to the chemical reaction for the reduction of iron ore, there can be no significant decrease in CO2 emissions without the development of breakthrough technologies, as proposed by ULCOS.
The industry is also facing a social challenge due to the increasing average age of its workforce: more that 20% will retire by 2015 and close to 30% during the following 10 years. The industry will therefore need to attract, educate and secure more qualified people.
There is a clear need to support the ULCOS research effort with a high share of public funds and to encourage the deployment of these breakthrough technologies.
One important synergy in the quest to curb prospective CO2 emissions through the ULCOS project is by sharing innovation initiatives within the power sector or with other (energy-intensive) manufacturing industries that could launch CCS initiatives (e.g. the cement industry).
Not all the European operators are performing as well as they could, so there is still potential to save energy by bringing them up to the level of the best performers.
The EU is the second leading manufacturer of iron and steel products in the world, China being the largest. The main EU steel producers are Germany, Italy, France, Spain, UK, Belgium and Poland. The USA is the main importer and the EU, Japan, Russia and Ukraine are the main steel exporting countries.
The annual turnover in the EU steel sector is approximately € 150 billion and it employs approximately 350 000 people. The outlook for employment in the steel sector is of serious concern and merits full political attention, as restructuring in the sector has seen the number of people employed fall from 416,000 in 2008.
The industry directly employs more than two million people worldwide, with a further two million contractors and four million people in supporting industries. World steel consumption in 2012 amounted to 1.413 billion tonnes, of which the EU-27 accounted for around 10% (140 million tonnes). Worldwide demand is forecast to increase to 1.552 billion tonnes by 2015.
For further information:
 EUROFER, European Steel in Figures 2008 - 2012.