Steel In The Circular Economy PDF

STEEL IN THE CIRCULAR ECONOMY A life cycle perspective CONTENTS Foreword 3 The circular economy 4 Life cycle thinking...

STEEL IN THE CIRCULAR ECONOMY A life cycle perspective CONTENTS Foreword 3 The circular economy 4 Life cycle thinking 6 The life cycle assessment (LCA) approach 8 worldsteel’s LCA methodology and life cycle inventory (LCI) database 10 Sustainability and life cycle assessment 12 LCA in the steel industry 14 LCA by life cycle phase 15 Raw materials and steel production 15 Markets for by-products 16 Manufacturing and use 16 Reuse and remanufacturing 18 Recycling 19 LCA initiatives 20 Regional and global initiatives 21 Market sector initiatives 22 Construction 22 Automotive 24 Packaging 25 End notes 28 Glossary 29 Cover image: Steel staircase, office building, Prague, Czech Republic Design: double-id.com  FOREWORD We live in a rapidly changing world with finite resources. Too many legislative bodies around the world At the same time, improvements in standards of living still enact regulations which only affect the “use and eradication of poverty, combined with global phase” of a product’s life, for example water and population growth, exert pressure on our ecosystems. energy consumption for washing machines, energy consumption for a fridge or CO2 emissions whilst As steel is everywhere in our lives and is at the heart driving a vehicle. This focus on the “use phase” can of our sustainable future, our industry is an integral part lead to more expensive alternative lower density of the global circular economy. The circular economy materials being employed but which typically have a promotes zero waste, reduces the amount of materials higher environmental burden when the whole life cycle used, and encourages the reuse and recycling of is considered. materials, all fundamental advantages of using steel. This offers a markedly different approach and outcome This use phase limitation cannot continue. Life cycle to the “take, make, consume and dispose” economic thinking must become a key requirement for all model the world has been used to. manufacturing decisions. This publication focuses on the importance of a life cycle approach in delivering true sustainability. It highlights for legislators and industry decision makers the importance of analysing the entire life cycle of a product before making legislative or manufacturing material decisions. Dr Edwin Basson Director General World Steel Association We would like to dedicate this publication to the memory of Jean-Sébastien Thomas (ArcelorMittal) who very sadly died recently. Jean-Sébastien was Chairman of the worldsteel LCA Expert Group for the last three years and was a committed and enthusiastic driving force behind our life cycle activities. Much of his passion and knowledge is incorporated in this publication. For more information about the technical terms used in this brochure, please see the Glossary, page 29. Linear business model LINEAR BUSINESS MODEL DESIGN RAW MATERIALS PRODUCTION MANUFACTURING USE DISPOSAL Steel in the circular economy  THE CIRCULAR ECONOMY “The steel industry is an integral part of the circular economy model. The circular economy promotes zero waste, reuse of materials and recycling. It offers a markedly different approach and outcome to the ‘take, make, consume and dispose’ economic model currently in use.” — Dr Edwin Basson, Director General worldsteel The circular economy is a move from linear business REUSE: Because of its durability, steel can be models, in which products are manufactured from reused or repurposed in many ways, with or without raw materials and then discarded at the end of remanufacturing. This already occurs with automotive their useful lives, to circular business models where components, buildings, train rails and many other intelligent design leads to products or their parts being applications. Reuse of steel is not limited to its original repaired, reused, returned and recycled.1 A circular application; repurposing dates back to ancient economy aims to rebuild capital, whether it is financial, times (turning swords into ploughshares). Reuse manufacturing, human, social or natural. This approach occurs in sectors where it is technically possible enhances the flow of goods and services.2 without reducing safety, mechanical properties and/ or warranties. Rates of reuse will increase as eco- The concept of the circular economy drives optimal design, design for reuse and recycling, and resource resource efficiency. It makes sure that resources efficiency become more commonplace. are efficiently allocated to products and services in such a way as to maximise the economic well- REMANUFACTURE: Many steel products, such being of everyone. In addition, products need to be as automotive engines and wind turbines, can be designed to be durable, easy to repair and, ultimately, remanufactured for reuse to take advantage of the to be recycled. The cost of reusing, repairing or durability of steel components. Remanufacturing remanufacturing products has to be competitive to restores durable used products to like-new encourage these practices. Simply replacing a product condition.3 It differs from repair, which is a process with a new one should no longer be the norm. limited to making the product operational, as opposed to thorough disassembly and restoration A circular economy ensures that value is maintained with the possible inclusion of new parts.4 within a product when it reaches the end of its useful life while at the same time reducing or eliminating R  ECYCLE: Recycling has been carried out in the waste. This idea is fundamental to the triple-bottom-line steel industry since steel was first made. Steel is concept of sustainability, which focuses on the interplay 100% recyclable and can be recycled over and between environmental, social and economic factors. over again to create new steel products in a closed Without a life cycle approach, it is impossible to material loop. Recycled steel maintains the inherent have a genuine circular economy. properties of the original steel. The magnetic property of steel ensures easy and affordable recovery for In a well-structured circular economy, the steel recycling from almost any waste stream while the industry has significant competitive advantages high value of steel scrap guarantees the economic over competing materials. Four keywords define viability of recycling. Today, steel is the most recycled these advantages: material in the world. Over 650 Mt of steel are R  EDUCE: Reducing the weight of products, and recycled annually5, including pre- and post-consumer therefore the amount of material used, is key to the scrap. circular economy. Through investments in research, The steel industry continues to further integrate these technology and good planning, steelmakers have advantages into its operations in order to highlight the over the past 50 years drastically reduced the benefits of steel to those people making decisions amount of raw materials and energy required to on material choices. Co-operation from the whole make steel. In addition, the steel industry is actively production chain is necessary to ensure that reused or promoting and developing the use of high-strength remanufactured products have the same properties as and advanced high-strength steel grades in many new steels. applications. These grades contribute to the lightweighting of applications, from wind turbines to construction panels and automobiles, as less steel is needed to provide the same strength and functionality. 5 Steel is 100% recyclable and can be recycled over and over again to create new steel products in a closed-material loop. Recycled steel maintains the inherent properties of the original steel. 6  LIFE CYCLE THINKING Every product we buy has a life cycle. Whether it is a to landfill because there is no economical way to food can, a car, or a washing machine, every product is recycle or reuse the material. Alternatively, they can be manufactured, used, and then can be reused, recycled downcycled to a lower grade product. It is important or disposed of at the end of its useful life. Steel that that this information is known before key material enters the waste stream can be easily separated and decisions are made. The whole life cycle, from raw collected from other materials for recycling, by the use material extraction through to end-of-life recycling or of magnets. disposal has to be considered. Life Cycle Thinking (LCT) is a term that is used to describe the holistic thinking that is needed to solve PACKAGING › Reducing thickness of steel society’s problems sustainably. Life cycle thinking for packaging has positive environmental requires us to consider the raw materials used, energy consumption, waste and emissions of a product across impact over its life cycle each phase of its life. This starts with design and ends The technology used to at the point where the product reaches the end of its manufacture the drawn useful life. A well-designed, steel-containing product wall ironing (DI) tinplate will already anticipate the reuse or recycling of its used in two-piece steel components at the end-of-life. food and beverage cans is very sophisticated. Only by calculating the resources and energy used, Since Baosteel first and the waste and emissions produced at every stage developed DI steel in along this journey can we define the true environmental 1998, its thickness has been reduced from impact of a product. This also enables us to identify 0.280 to 0.225mm. where its long-term environmental sustainability The thinner DI tinplate can be improved. For example, the small increase is widely used in the beverage packaging industry. in energy consumption or the addition of alloying elements required to produce high-strength steels is Reducing material thickness requires additional rolling of the steel, which slightly increases the energy compensated many times over when you consider consumption of the reheating furnace and the rollers. the life cycle of the product. Using these high-strength However, reducing the thickness of DI tinplate brings steels means that products can be lighter 6 and benefits. Less steel is required and the production rate therefore often save energy during the use phase of of finished cans is greatly improved. Transport impacts their life, for example, when applied to the automotive are also reduced. This decreases emissions and energy sector. Over the entire life cycle of the product, less consumption. energy is used. The life cycle environmental benefits of the thinner DI There is another reason why life cycle thinking is very material were quantified in an LCA of two-piece steel important. By knowing the actual impact of each stage cans made by the Baoyi Can Making Co. Ltd. Reducing the thickness of the steel from 0.280 to 0.225 mm has of a product’s life, we can make the best decisions on decreased the weight of the material used as well as what materials we should use. reduced the CO2 emissions of two-piece steel cans For example, in addition to high-strength steels, low by 14.5% over their life cycle. density materials such as aluminium, carbon fibre or Source: Baosteel plastics are sometimes used to make applications lighter. However, manufacturing low density materials can involve a much more expensive or environmentally damaging production process. At the end of the product’s life, these materials may need to be sent 7 The life cycle assessment (LCA) LCA generally comprises four stages: approach 1. G  oal and scope definition: Identify the purpose of the study and its boundaries. Life cycle assessment (LCA) is a tool that enables us to measure the holistic environmental impact or 2. Life cycle inventory (LCI): Data collection and performance of a product at each stage in its life cycle. calculation to create an inventory (a list of inputs It provides a measure which can be used to compare and outputs) of the materials, energy and emissions the environmental sustainability of similar products and related to the product being studied. services which have the same function. 3. L  ife cycle impact assessment (LCIA): Quantify LCA considers the potential impacts from all stages of the potential environmental impacts based on the the material’s life cycle including manufacture, product life cycle inventory of a specific product or system. use and end-of-life stages. This is referred to as the One of the most commonly referred to impacts is cradle-to-grave approach. When the material is fully the global warming potential (GWP) which defines recycled back into the same material, with no loss in greenhouse gas emissions expressed in terms of quality, as is the case for steel, this can be referred to CO2-equivalents. as the cradle-to-cradle approach. 4. Interpretation: Identify the significant environmental issues, make conclusions and recommendations. Steel’s life cycle Steel production Raw material Pr st -c e extraction ee on 10 E l s sum ap r 0% e R cr L s t ee l sum EC a p er B LA YC scr LA on YC BLE Manufacturing EC Pos t -c 10 0 % R Reuse and remanufacturing Steel recycling Use Source: worldsteel 8  LIFE CYCLE THINKING The quality and relevance of LCI/LCA results, and the Technical Specification ISO TS 14067: 2013 - carbon extent to which they can be applied and interpreted, footprints depend on the methodology used. The International ISO 14046: 2014 - water footprints Organisation for Standardisation (ISO) has developed ISO 14025: 2006 - environmental labels and standards which provide guidance on methodological declarations choices and set down rules for transparency and ISO 21930: 2007 - sustainability in building reporting. The relevant ISO standards on LCA are construction (currently being updated) covered in: GHG Protocol (WRI/WBCSD) ISO 14040: 2006 - Environmental management - Life Product Category Rules (PCRs) are becoming cycle assessment - Principles and framework increasingly important as these are documents that ISO 14044: 2006 - Environmental management - Life define the rules and requirements for Environmental cycle assessment - Requirements and guidelines Product Declarations (EPDs) of a specified product These standards form the basis of a number of other category. Following ISO 14025: 2006 (Type III standards which focus on specific issues related to environmental labels and declarations), PCRs are vital LCA. Some examples include: to ensure transparency and comparability between different EPDs based on the same PCR. Durability of steel were manufactured in Belgium and shipped to the Philippines where the church was assembled. A circular economy promotes long product lives. The The iconic Sydney Harbour Bridge has been carrying longer a product lasts the less raw materials will need to road and rail traffic since it opened in 1932. The be sourced. Product durability contributes to reducing bridge contains over 53,000 tonnes of steel waiting the depletion of raw materials. to be recycled. By 2050, an estimated 9 billion people will inhabit None of these structures are scheduled to be the Earth. Steel is an enabler of the sustainable replaced in the foreseeable future. development needed to meet the needs of these Steel’s durability is one of the key properties that make people. it a sustainable material. Not only does steel ensure In theory, all new steel could be made from recycled long product life, it also allows the reuse of countless steel. However, this is not practically feasible due to the products, from paper clips to rail and automotive long life of steel products, given steel’s strength and components (see Reuse and remanufacturing on durability. Around 75% of steel products ever made are page 18). still in use today.7 Buildings and other structures made from steel can last from 40 to 100 years and longer if proper maintenance is carried out. For example: In 1883, New York’s Brooklyn Bridge became the world’s first steel bridge to carry traffic. Over 130 years later it still carries over 120,000 vehicles a day. Completed in 1891, the Basilica of San Sebastien in the Philippines capital, Manila, remains the only pre-fabricated steel church in Asia. Sections Sydney Harbour Bridge 9 There are many different grades of steel ranging from mild conventional steels to high-strength steels, advanced high-strength steels and specialty steels such as stainless. Each grade of steel has properties designed for its specific application. worldsteel’s LCA methodology and electronic appliances). By collecting data from different regions, worldsteel can identify and encourage the use life cycle inventory (LCI) database of best practices amongst its global membership. worldsteel’s LCI data covers the raw material and ent production phases (cradle-to-gate) of the steel life o v em pr Da cycle. This data includes environmental inputs and m t outputs such as resource use (raw materials, energy ti a uc co and water) and emissions to land, air and water from od l lec Process/pr each process within the steelworks. These processes t i on ( LC I ) worldsteel include cokemaking, steel production, final processing LCA methodology of steel products, and other necessary processes such as boilers, power plants and waste water treatment. worldsteel also provides a detailed methodology to En vir nm consider the benefits obtained by recycling steel from nt e o en m tal ss products that have reached the end of their useful life im pact asse (see appendix 10 of the methodology report). This data is also available from worldsteel, based on specific The methodology worldsteel uses to calculate the LCI end-of-life recycling rates of the product. By recycling of steel products is documented in the association’s steel, less primary raw materials are needed. Recycling Life Cycle Assessment (LCA) methodology report, accounts for significant energy and raw material 2011. The methodology is aligned to international savings: over 1,400 kg of iron ore, 740 kg of coal, and standards for the calculation of LCA (ISO 14040: 2006 120 kg of limestone are saved for every tonne of steel and ISO 14044: 2006). The methodology has been scrap made into new steel. peer-reviewed by an external panel at each update. Using this product-specific LCI data on a global or Both the methodology and the database are updated regional basis, the environmental impact, or LCA, can regularly to keep them current and relevant to the be calculated for a final product, from cradle to grave. market. worldsteel has been collecting life cycle inventory (LCI) data from its global membership since 1995. Two Also at worldsteel.org: updates of worldsteel’s global LCI database were made LCA methodology report 2011 in 2001 and 2010 and it is being updated again in LCI data request form for 15 steel products 2015. The LCI data is available to worldsteel member companies and third-parties. The full database is maintained by worldsteel. The data enables academics, architects, government bodies, steel customers and other interested parties to undertake LCA studies of steel-containing products. Anyone wishing to undertake such a study can obtain global and regional LCI data for 15 steel products by completing the request form available on worldsteel. org. The data can be used across all market sectors (for example, automotive, building, packaging, energy, 10  LIFE CYCLE THINKING “At first glance, materials that weigh less or, more precisely, have a lower density than steel, such as aluminium, carbon fibre, magnesium and plastics may appear to be interesting alternatives. However, when the total life cycle of a material is taken into account, steel remains competitive, owing to its strength, durability, recyclability, versatility and cost” — Prof. Jean-Pierre Birat, Secretary General European Steel Technology Platform AUTOMOTIVE › Life cycle thinking leads to intelligent automotive material choices The global transportation industry is a significant contributor The use of LCA gives a much more accurate picture of the to greenhouse gas emissions and accounts for about 23% environmental impact of the vehicles that we drive. It is for this of all man-made CO2 emissions. Regulators are addressing reason that worldsteel and steelmakers agree that life cycle this challenge by setting progressive limits on automotive thinking should play a role in future regulations, but further emissions, fuel economy standards or a combination of both. research is needed on how this can be implemented. Many of the existing regulations began as metrics to reduce Comparison of CO2 emissions of standard VW Golf oil consumption and focused on extending the number against AHSS-intensive Golf and multi-material* Super of kilometres/litre (miles/gallon) a vehicle could travel. This Light Car (SLC) approach has been extended into the regulations which now limit GHG emissions from vehicles. Body-in-white mass, kg The steel industry believes that this approach needs an urgent 300 280 kg review. Extending the fuel economy metric to meet objectives 250 225 kg to reduce emissions is resulting in unintended consequences. 200 180 kg Low-density alternative materials are being used to reduce vehicle mass. These materials may achieve lighter overall 150 vehicle weights, with corresponding reductions in fuel consumption and use phase emissions. However, the 100 production of these low-density materials is typically more 50 energy and GHG intensive, and emissions during vehicle production are likely to increase significantly. These materials 0 Standard VW Golf AHSS-intensive, Super Light Car, are often not able to be recycled and need to be sent to (= baseline) VW Golf (AHSS) multi-material concept (SLC) landfill. Numerous LCA studies show how this can lead to higher emissions over the entire life cycle of the vehicle as well Manufacturing, emissions, % Use phase emissions, % as increased production costs. 60 0 AHSS SLC A study of the Toyota Venza compared the life cycle 40 48% emissions of two body structures: one dominated by high- 20 -5 strength steels and the other using a magnesium/aluminium AHSS 0 -7% structure which is 104 kilograms lighter. Carried out by the SLC -10 -20 -10% independent University of California at Davis, the study found -21% -40 that, while emissions during the use phase decreased by -15 6% in the magnesium/aluminium vehicle, emissions during Reduction in lifetime emissions, % Additional production costs, Euros the entire life cycle increased by 7% compared to the high- AHSS SLC €795 strength steel design. -6,0 800 The Super Light Car (SLC), a European multi-material 600 project, achieved a 36% reduction in the weight of the -6,2 body-in-white compared to the baseline vehicle, a standard 400 -6.3% VW Golf. Emissions during the driving phase of the SLC’s -6,4 200 life were reduced by 10%, and by 6.5% over its entire life cycle compared to the baseline vehicle. However, during the -6.5% €0 -6,6 0 production phase, emissions were 44% higher and costs were AHSS SLC significantly increased - up to €795 per vehicle. By contrast, a VW Golf manufactured from advanced high-strength steels *Materials used in SLC: 53% aluminium, 36% steel, (AHSS) would lead to a 6.3% reduction in emissions over 7% magnesium and 4% plastic. the vehicle’s entire life. This is just 0.2% lower than the SLC vehicle. During the manufacturing phase of the AHSS vehicle, emissions are reduced by 21% at no extra cost. Source: WorldAutoSteel 11 12  SUSTAINABILITY AND LIFE CYCLE ASSESSMENT Life cycle thinking: of steel, including a 60% drop in energy consumption per tonne of steel produced.9 The environmental Key to every aspect of sustainability benefits related to steel’s durability, allowing for long product lifetimes and reuse, and its recyclability are also crucial factors that make steel a sustainable material. SOCIAL Social Life Cycle Assessment Social sustainability is achieved if the manufacture, (SLCA) use and end-of-life processes for a given product are respectful of the human being and ensure that future generations can enjoy the same lifestyle we do today. This involves protecting the health and safety SUSTAINABILITY of the people who make or use a product, managing resources for future generations, and ensuring that ENVIRONMENT ECONOMIC social issues such as inequality and poverty are Life Cycle Assessment Life Cycle Costing addressed. (LCA) (LCC) Economic sustainability requires businesses to make ethical profits which are used to ensure the long- term viability of their enterprises. In turn, this creates sustainable employment which has a positive impact In 2012, 66 members of worldsteel signed the on the well-being of people and communities. worldsteel Sustainable Development Charter8 which More than two million people are directly employed by commits them to improving the social, economic and the steel industry with a further two million contractors environmental performance of their companies. By on site. Indirectly, many millions more have jobs with signing the Charter, worldsteel’s members agreed to upstream suppliers and in the downstream industries operate their businesses in a financially sustainable that rely on steel. In turn, these people and businesses way, supply steel products and solutions that satisfy contribute to their own communities through taxes and customer needs and provide value, optimise the eco- by providing further employment.10 efficiency of steels throughout their life cycle, and foster the well-being of employees and communities. While LCA is typically applied to environmental sustainability, an ‘integrated life cycle approach’ The Charter represents a definitive commitment by the can also be used to measure the social LCA global steel industry to embrace life cycle thinking and and economic impact (life cycle costing, LCC) of all three pillars of sustainability (economic, social and products. Keeping all three in balance is key if we environment). are to make sustainable products. The steel industry is one of the few industries to It is important to note that social and economic monitor and report its sustainability performance at factors are as critical as environmental factors if the global level, since the first sustainability report we are to create industries and societies which are was published in 2004. This has enabled the steel truly sustainable. industry to benchmark its performance and to enhance transparency. Most companies also report on their sustainability performance individually. Also at worldsteel.org: In terms of environmental sustainability, changes at Sustainable steel: Policy and indicators 2014 every phase in the steel production process over the Safety and health section past 50 years have resulted in significant improvements in the resource and energy efficiency in the production 13 14 Source: Severstal  LCA IN THE STEEL INDUSTRY “Steel is the most recycled material in the world. As more steel scrap becomes available, the steel industry will close the loop in the circular economy and will further reduce its need for raw materials” — Dr Paul Brooks, Chairman, Environment Committee, worldsteel and Group Director, Environment, Tata Steel LCA by life cycle phase Steel is made through one of two main production routes: Every product goes through a series of phases during The blast furnace or integrated route: based on its lifetime (see page 4 and 8). The first is design where the blast furnace (BF) and basic oxygen furnace the product is defined. This stage should consider the (BOF). To produce 1,000 kg of crude steel, the main sustainable use of the product as well as including inputs are (approximately) 1,400 kg of iron ore, 800 kg provisions for the sustainable reuse and recycling of the of coal, 300 kg of limestone, and 120 kg of steel product once its use phase comes to an end. scrap.11 About 70% of the world’s steel is produced via this process.12 The next phase is raw material selection, followed The electric arc furnace (EAF) route: Primary raw by manufacturing, use, reuse (which may include materials are steel scrap and/or direct reduced iron remanufacture) and then recycling. At the end of the (DRI) or hot metal and electricity. To produce 1,000 process, the recycled material is transformed into a kg of crude steel, the EAF route uses (on average) new product and the cycle begins again. 880 kg of steel scrap, 300 kg of iron, 16 kg of coal and 64 kg of limestone. The EAF route can also be Raw materials and steel production charged with 100% steel scrap. About 30% of the Key raw materials needed in steelmaking include iron world’s steel is produced via the EAF process.12 ore, coal, limestone and steel scrap (or recycled steel). Another steelmaking technology, the open hearth With the exception of steel scrap, the ingredients for furnace (OHF), makes up about 1% of global steel steelmaking are still relatively abundant. Steel scrap production and is in decline owing to its environmental is in short supply globally, largely due to the long and economic disadvantages. service life of steel in infrastructure. However, the steel industry recycles as much steel scrap as possible that The blast furnace route always uses some scrap (can becomes available. be up to 35%). An EAF can be charged with 100% The steel production routes LUMP ORE FINE ORE LUMP ORE FINE ORE sinter pellets Raw coal material preparation pellets recycled coke steel Blast BF Furnace Direct Reduction DR coal natural gas, natural gas, Ironmaking oil or coal blast oil natural gas O2 shaft rotary kiln fluidized furnace furnace bed hot metal DRI air oxygen recycled steel Alternative recycled recycled input steel Steelmaking steel OHF BOF EAF EAF Crude steel 15 steel scrap but can use no scrap when it is charged complements the continual steps they are taking to with 100% DRI. There is not enough end-of-life steel reduce other emissions such as dust, NOx and SOx available to produce all new steel from recycled from the steelmaking processes.13 sources. The steel industry has dramatically reduced its energy Markets for by-products consumption over the past half century.9 Members of In addition to reducing their demand for raw materials, worldsteel are collectively and individually exploring steelmakers have become more effective at reducing the development of new breakthrough technologies waste and finding markets for the by-products which may make it possible to reduce the energy produced in the steelmaking process. This helps to consumption and CO2 emissions of the steelmaking significantly reduce waste from steel’s life cycle. Today, process further. Steel producers are also working to approximately 96% of the raw materials used to make reduce the impact of CO2 emissions through the use crude steel are converted into steel products or by- of carbon capture and storage technologies. This products.15 The aim is to increase this to 100%. Average GHG emissions during global material production The industry has made significant efforts to find new (In kg CO2e/kg of material) including finishing14 markets and applications for its by-products which include slags, process gases (coke oven, blast furnace Steel 2.0-2.5 and basic oxygen furnace gases), tar and benzene. Aluminium 16.5-16.6 Slag, one of the steel industry’s major by-products, is Magnesium now widely used in the cement industry. This reduces 36-56 the environmental burden of cement production. CFRP* 21-23 According to the Slag Cement Association, replacing Portland cement with slag cement in concrete can save Note: 1kg of steel is not equal to 1kg of another material. up to 59% of the embodied CO2 emissions and 42% of Functional units also need to be compared (see table below the embodied energy required to manufacture concrete for more details on estimated functional units). and its constituent materials.16 However, this does not account for the CO2 emissions associated with Functional units producing slag. Slag has other applications as a crop Material production GHG emissions comparison fertiliser (it is rich in phosphate, silicate, magnesium, for a typical automotive part lime, manganese and iron) and as an aggregate in road Mid-Range CO2e Estimated Part Weight (kg) building. Conventional 2.3 100 steel AHSS** 2.3 75 Manufacturing and use Aluminium 16.5 67 Magnesium 46.0 50 During the manufacturing phase, intermediate steel CFRP* 22.0 45 products (for example, hot rolled coil) are transformed into steel-containing products such as automobiles. Conventional steel 230 One of the key benefits of steel is that it can be AHSS** 173 designed to meet the specific strength, durability, kg CO 2 e Aluminium 1,106 and end-of-life recycling requirements of almost any Magnesium 2,300 application. Steel makes up nearly 60% (by mass) of North American vehicles, and 50% in the rest of the CFRP* 990 world.17 Using advanced high-strength steels (AHSS) makes it possible to design lighter, optimised vehicles *CFRP: Carbon Fibre Reinforced Plastic which enhance safety, improve fuel economy and **AHSS: Advanced High-Strength Steel reduce lifetime greenhouse gas emissions. 16  LCA IN THE STEEL INDUSTRY Ongoing research is producing new steels that are grade steels is expected to reduce the quantity of steel even stronger and lighter than those available today. used in construction. Transportation costs are also Wind tower turbines, vital for producing clean wind reduced thanks to the thinner, and therefore lighter, energy, are already 50% lighter than they were a steel components. They also shorten the time needed decade ago.18 For a 70-metre tower, that translates for processing at plants and on-site construction, into a 200 tonne reduction in CO2 emissions.18 With largely due to a reduction in the number of welds their higher strength-to-weight ratio, the newer steels required. Using these steels, it is possible to reduce can be used to manufacture tower sections of up to the number of columns in building structures and make 30-metres. This reduces emissions during transport them thinner. This results in larger areas and provides and assembly. opportunities for better design and use of space. Higher grade steels enable structures to be developed Higher grade steels are also being developed for which incorporate dissipation mechanisms to absorb construction. They enable the construction of larger the majority of the seismic energy generated by an and taller buildings in a more efficient way and produce earthquake.19 the lowest possible amount of waste. The use of higher WIND ENERGY › Using LCA to calculate A significant reason for this is the high level of steel and iron used in the V112-3.3 MW wind turbine (up to 84% energy payback for wind turbines of the total weight). At the end of the turbine’s useful life, Based in Denmark, Vestas all of this steel and iron can be recycled into new steel is a global manufacturer products with the same, or improved, properties. of wind turbines. Since At least 83% of the V112-3.3 MW turbine is recycled. 1999, the company has The components contributing to its recyclability include been using LCA to develop metal parts which are primarily manufactured from energy-efficient products steel and iron. Overall, around 86% of the V112-3.3 and production methods MW turbine is made from metals (see diagramme for as well as mitigating the materials breakdown). The benefits of recycling the steel environmental impact of its from the turbine at the end of its life lead to a reduction wind turbines over their entire of 15% in the global warming potential (GWP) and a 10% lifetime. improved energy payback. A cradle-to-grave LCA study has enabled Vestas to calculate the energy payback of its V112, 3.3-megawatt Materials breakdown (V112-3.3 MW) wind power plant. The calculation takes into account the energy required to manufacture, Steel and iron materials (84%) operate, service and dispose of the plant. Aluminium alloys (1%) The calculation shows that the energy required to Copper and alloys (