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Comparison of carbon dioxide emissions intensity of steel production in China, Germany, Mexico, and the United States

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Abstract

Production of iron and steel is an energy-intensive manufacturing process. The goal of this study was to develop a methodology for accurately and more fairly comparing the energy-related carbon dioxide (CO2) emissions intensity of steel production in different countries and to demonstrate the application of this methodology in an analysis of the steel industry in China, Germany, Mexico, and the U.S. Our methodology addresses the industry’s boundary definition, conversion factors, and industry structure. The results of our analysis show that, for the entire iron and steel production process, the base-case (2010) CO2 emissions intensity was 2148 kg CO2/tonne crude steel in China, 1708 kg CO2/tonne crude steel in Germany, 1080 kg CO2/tonne crude steel in Mexico, and 1736 kg CO2/tonne crude steel in the U.S. One of the main reasons that Mexico has the lowest CO2 emissions intensity is Mexico’s large share of steel production using electric arc furnaces (EAFs) (69.4%). EAF steel production has lower CO2 emissions intensity than production using blast furnaces/basic oxygen furnaces. China, by contrast, has the smallest share of EAF production among the four countries—9.8% in the base-case year 2010. In one scenario, we applied the Chinese share of EAF production to the other three case-study countries; the result was an increase in CO2 emissions intensity of steel production of 19% (2036 kg CO2/tonne crude steel) in Germany, 92% (2074 kgCO2/tonne crude steel) in Mexico, and 56% (2703 kg CO2/tonne crude steel) in the U.S. compared to these countries’ base-case analyses. In another scenario, we applied the Chinese national average grid electricity CO2 emissions factor from 2010, which is the highest emissions factor among the four countries, to the other three countries. In that scenario, the CO2 emissions intensity of steel production increased by 5% in Germany, 11% in Mexico, and 10% in the U.S.

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... In fact, despite the various efforts to promote and/or develop alternative materials (e.g., wood construction or glass reinforced polymers for structural applications), the Global Cement and Concrete Association [3] estimates a yearly increase in demand from the current 14 billion m 3 of concrete to approximately 20 billion m 3 in 2050. Moreover, the specific (by volume or by weight) environmental impact of concrete is lower than many alternative construction materials (e.g., about 300 kg CO 2 /tonne for a standard concrete mix versus over 1000 kg CO 2 /tonne for steel) [2,[4][5][6] because the components that make up most of its volume (aggregates) are naturally abundant and relatively easy to obtain. However, most of the concrete produced incorporates Portland cement as the key binder, which is responsible for the majority of the environmental impacts. ...
... [47] is 82 g CO 2 /tkm, and this value was used in the simulations. An average distance of 120 km (both ways) was considered adequate, considering the size of Portugal (≈600 × 200 km) and the number of cement plants (6). ...
... Therefore, an estimate of around 270 kg of CO 2 per m 3 of concrete is obtained if considering the entire chain of the concrete production. This value is smaller than the 300 kg/m 3 of CO 2 per m 3 of concrete usually considered in the literature, which is based on the most common cement dosage of 350 kg of cement per m 3 of concrete [2,[4][5][6]. Conversely, the value of 270 kg of CO 2 per m 3 of concrete considers the distribution of concrete throughout the different cement dosages and is a better estimate of the CO 2 emission of concrete production. Table 4 also shows that, in the scenario of carbonating both concrete element types, this CCUS technology reduces the amount of CO 2 released per m 3 of concrete from 236 kg to 215 kg, a reduction of about 9.1% of the CO 2 emissions into the atmosphere. ...
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... In fact, despite the various efforts to promote and/or develop alternative materials (e.g., wood construction or glass reinforced polymers for structural applications), the Global Cement and Concrete Association [3] estimates a yearly demand increase from the current 14 billion m 3 of concrete to approximately 20 billion m 3 in 2050. Moreover, the specific (by volume or by weight) environmental impact of concrete is lower than many alternative construction materials (e.g., about 300 kg CO2/tonne for a standard concrete mix versus over 1 000 kg CO2/tonne for steel) [2,[4][5][6], since the components that make up most of its volume (aggregates) are naturally abundant and relatively easy to obtain. However, most of the concrete produced incorporates Portland cement as the key binder, which is responsible for the majority of the environmental impacts. ...
... The conversion between mass and volume of CO2 was done adopting a specific weight of 1.836 kg/m 3 at ambient temperature. 6 The emissions from CO2 supply entail the liquefaction, transport, vaporization and injection, as depicted in Figure 3. In complement to the typical deterministic approach, a stochastic analysis was also carried out resorting to Monte Carlo simulation. ...
... Therefore, an estimate of around 270 kg of CO2 per m 3 of concrete is obtained if considering the entire chain of the concrete production. This value is smaller than the 300 kg/m 3 of [2,[4][5][6]. Conversely, the value of 270 kg of CO2 per m 3 of concrete considers the distribution of concrete throughout the different cement dosages, being a better estimate for the CO2 emission of concrete production. Table 4 also shows that, in the scenario of carbonating both concrete element types, this CCUS technology reduces from 236 kg to 214 kg of CO2 released per m 3 of concrete, a reduction of about 9.4% of the CO2 emission into the atmosphere. ...
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The concrete sector is known for its significant contribution to the CO2 emissions. There are two main contributing factors for this situation: the large amount of concrete consumed per year on the planet and the high CO2 released from Portland cement manufacture, the key binding agent in concrete. To face the consequent sustainability issues, diverse strategies have been explored on the carbon capture and storage potential of cementitious materials. This paper addresses the potential of storing CO2 in concrete during the curing stage, applied to the precast Portuguese industry. To this purpose, it was assumed that CO2 will become a waste that will require an outlet in the future, considering that carbon capture will become mandatory in many industries. This work concluded that the net benefit in terms of carbon retention is positive for the process of storing carbon in concrete during the curing stage. More specifically, it was demonstrated that the additional emissions from the introduction of this new operation are only 10% of the stored amount, returning a storage potential of 76 000 tonnes of CO2 yearly. Moreover, the overall net reduction in the concrete life cycle averages 9.4% and 8.8% for precast elements and only non-structural elements, respectively. When a low cement dosage strategy is coupled with carbonation curing technology, the overall carbon net reduction is estimated to be 45%.
... The energy demand and GHG emissions are determined by structural parameters like scrap availability, the regional power mix and energy supply, the lifetime, and the used technologies [34]. Based on this, the different manufacturing routes should be compared against the same technologies across different countries, as, for example, the average emission intensity of a country can be misleading [35]. Hotspots for the BF-BOF process are tblast furnaces with 61%, and coke-making plants, with 27% of total CO 2 emissions [36]. ...
... For EAF, the electricity demand for smelting is responsible for the most GHG and depends on the spatial grid mix [32,37]. Figure 5 [26,30,32,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] shows the comparison of emission intensities for steel manufacturing routes where the global average is at 1.9 tCO 2 /t. For the main contributor BF-BOF, the values found in the literature vary from 1.7 tCO 2 /t to Sustainability 2023, 15, 11795 7 of 20 2.8 tCO 2 /t (3.5 tCO 2 /t), and for EAF the range is 0.12 tCO 2 /t to 1.2 tCO 2 /t. ...
... For EAF, the electricity demand for smelting is responsible for the most GH depends on the spatial grid mix [32,37]. Figure [26,30,32,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51] shows the comparis emission intensities for steel manufacturing routes where the global average is tCO2/t. For the main contributor BF-BOF, the values found in the literature vary fro tCO2/t to 2.8 tCO2/t (3.5 tCO2/t), and for EAF the range is 0.12 tCO2/t to 1.2 t Alternatives are also included that are relevant for their decarbonization pote Therefore, the DRI-NG route has an emission intensity of 1.3 tCO2/t to 1.4 tCO2/t, th EAF 0.76 tCO2/t to 1.5 tCO2/t and smelt reduction (SR) has an emission intensity tCO2/t. ...
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... Hence, the CEF parameters from one country cannot be directly referenced in another. Hasanbeigi et al. (2016) compared the 2010 CE intensities for the steel industries in China, Germany, Mexico, and the United States; the CE values for crude steel production in the four countries were 2148, 1708, 1080, and 1736 kgCO 2 /t, respectively. A major reason for the low CE intensity for crude steel in Mexico was the greater popularity of the electric arc furnace (EAF) method in steelmaking (a 69.4% proportion in Mexico and 9.8% proportion in China) (Hasanbeigi, 2016). ...
... Hasanbeigi et al. (2016) compared the 2010 CE intensities for the steel industries in China, Germany, Mexico, and the United States; the CE values for crude steel production in the four countries were 2148, 1708, 1080, and 1736 kgCO 2 /t, respectively. A major reason for the low CE intensity for crude steel in Mexico was the greater popularity of the electric arc furnace (EAF) method in steelmaking (a 69.4% proportion in Mexico and 9.8% proportion in China) (Hasanbeigi, 2016). According to the WSA, for every additional kg of recycled scrap used as raw material, the CEF of crude steel could be reduced by 1 kgCO 2 e/kg (World Steel Association, 2011). ...
... Zhang et al. (2021) conducted a review of CE reduction technologies in the steel industry around the world and inferred that non-BF technologies have great prospects (Zhang, 2021). The CE reduction potential of EAF crude steel to BF-BOF was assessed in numerous studies Zhang, 2018;Chen et al., 2014;Hasanbeigi et al., 2016), but the ratio of EAF in China was assumed to be different. The CE reduction effect of EAF was largely influenced by the carbon intensity of electricity (Arens, 2017). ...
... It was assumed the liquefaction and reconditioning equipment remain functional over the lifetime of the project but require a maintenance cost of 4 % of CAPEX/y (Towler and Sinnott, 2021). The Scope 3 emissions were simplified as steel and concrete requirements based on the engineering estimate of equipment mass and footprint, respectively (Andrew, 2018;Hasanbeigi et al., 2016;Towler and Sinnott, 2021). It was assumed that no ammonia leaks from the system and that ammonia is provided from a zero-CO 2 source. ...
... Carbon dioxide emissions from the manufacturing of trucks was calculated using the GREET model (Wang et al., 2022). For all other equipment, US-based materials production CO 2 intensity factors were applied to the engineering estimates of equipment mass and composition (Andrew, 2018;Hasanbeigi et al., 2016). Likely reductions in material CO 2 intensities from industrial decarbonization are not considered due to currently high levels of quantitative uncertainty. ...
... It was assumed the liquefaction and reconditioning equipment remain functional over the lifetime of the project but require a maintenance cost of 4 % of CAPEX/y (Towler and Sinnott, 2021). The Scope 3 emissions were simplified as steel and concrete requirements based on the engineering estimate of equipment mass and footprint, respectively (Andrew, 2018;Hasanbeigi et al., 2016;Towler and Sinnott, 2021). It was assumed that no ammonia leaks from the system and that ammonia is provided from a zero-CO 2 source. ...
... Carbon dioxide emissions from the manufacturing of trucks was calculated using the GREET model (Wang et al., 2022). For all other equipment, US-based materials production CO 2 intensity factors were applied to the engineering estimates of equipment mass and composition (Andrew, 2018;Hasanbeigi et al., 2016). Likely reductions in material CO 2 intensities from industrial decarbonization are not considered due to currently high levels of quantitative uncertainty. ...
... 24 The high proportion of hot metal use in "Chinese-style" EAF leads to a high emission factor of 1.5 t CO 2 /t steel. 22 Life-cycle assessment literature attempted to re-evaluate CO 2 eq emissions, typically ignoring the effects of off-gas use and upstream energy/material extraction processes. 25,26 In China, the long economic life and new age of steel production facilities also impede decarbonization for ISI. ...
... Due to the CO 2 eq emissions from BF hot metal, the Chinese-style EAF has a higher EI CO2 (1.145 t CO 2 eq/t steel) than the IPCC value (0.080 t CO 2 eq/t steel) 19 but lower than the values obtained by Na et al. (3.07 t CO 2 eq/t steel) 70 and Hasanbeigi et al. (1.5 t CO 2 eq/t steel). 22 Promoting EAF is regarded as an important measure for reducing CO 2 eq emissions in ISI. However, the EAF route does not play a significant role in reducing CO 2 emissions for China's ISI, likely due to the high EI CO2 . ...
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... Among these, the vast majority of production, 90%, results from the blast furnace-basic oxygen furnace (BF-BOF) method, and 10% results from the electric arc furnace (EAF) method. Meanwhile, due to the difference in raw materials and energy sources, the CO 2 that results from producing one ton of crude steel can vary significantly [5]. According to World Steel Organization, the BF-BOF method emits around 1.8 tons of CO 2 per ton of steel produced, and the EAF method, which uses primarily scrap steel and can be powered by low-carbon electricity, emits around 0.4 tons of CO 2 per ton of steel produced. ...
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... Moving steel production to EAF, DRI-EAF: approximately 70% of steel in the world is produced through the BOS-BOF route, which uses coke as a reducing agent to produce iron from iron ore. Steel produced using this method has an embodied carbon of around 2.6 t CO 2 /t of steel [18,19]. Twenty-three per cent of steel production is from recycled steel scrap in EAF [13]. ...
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... According to the official data released by the Sichuan Provincial Economic and Information Department, the proportion of regional short-process steelmaking reached about 40% in 2022, which was much higher than the national average. Its production principle of "steelmaking with steel" could eliminate the sintering and reduction process of iron ore, thus effectively controlling energy consumption and carbon emissions, which is consistent with the findings of Hasanbeigi et al. [93]. From 2015 to 2022, the carbon emission level of glass and calcium carbide production was generally low. ...
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... The speed of phase transformations in steels, including the developments of pearlitic morphology and spheroidization have a direct impact on the carbon footprint of the manufactured products [23,24]. In today's environmentally conscious world, reducing energy consumption and greenhouse gas emissions are pressing concerns [25,26]. ...
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... This is close to what Sahoo calculated, but a little lower [25]. The result is also lower than the 2.15 tonnes of CO 2 mentioned by Hasanbeigi [52]. Emissions vary from year to year due to the different proportions of materials used. ...
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... The steel industry is considered a crucial basic industry and plays a key role in strengthening the national economy. Characterized by high energy intensity, large production volume, and significant reliance on coal as the main energy source, the steel industry's energy demand and CO2 emissions account for approximately 8% and 7% of the global totals, respectively [1][2][3]. The European Union's energy policy aims to reduce dependence on fossil fuels by promoting the use of renewable energy sources and carbonfree reagents [4][5][6][7]. ...
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... According to the presented diagrams, it can be concluded that steel production using the EAF technology is more profitable in terms of the load on the environment. Other studies also show similar results ( Figure 6) [Hasanbeigi et al. 2017]. ...
... For the experiments, this paper devises instances using data gathered from several Brazilian previous studies approaching steel production and transportation (Hasanbeigi et al., 2016;Conejo et al., 2020). ...
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... Carbon emissions from the production of concrete, steel and OPBF were assumed as 173 kgCO 2 /m 3 [68], 1.9 kgCO 2 /kg [69] and 0.0 kgCO 2 /m 3 respectively. Using the quantities calculated in Table 3 for design examples 1, 2 and 3, the quantities of CO 2 emission were calculated for concrete, steel and OPBF by multiplying the volume of the three materials with their respective unit CO 2 emissions. ...
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... In steelmaking, emissions and costs are highly affected by the considered geographic region (Hasanbeigi et al., 2016). We specify our assessment for Germany as the origin of most European steel. ...
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Due to climate change, there is an urgent need to decarbonize high-emission industries. As coal-based operations predominate in primary steelmaking, the steel industry offers an exceptionally high potential for reducing greenhouse gas emissions. Alternative processes for almost fully decarbonized primary steelmaking exist but require substantial investments by steelmakers for their implementation while maintaining desired production levels during the transformation periods. In this context, the energy carriers required change such that the transformation of the steelmaking processes is deeply intertwined with the transformation of the background system. For the first time, we evaluate potential transformation pathways from the steelmakers' perspective using a prospective life cycle assessment approach. We find that hydrogen may facilitate a reduction of direct emissions by around 96 % compared to conventional steelmaking in 2050. However, indirect emissions remain at a high level throughout the transformation period unless the upstream stages of the value chain are transformed accordingly.
... As we all know, the manufacturing industry stands as the primary consumer of energy and a major emitter of carbon dioxide [11][12][13][14]. Very recently, global semiconductor manufacturers have announced plans to expand chip manufacturing capacities to meet the surge in demand for chips [15][16][17]. ...
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Block copolymer (BCP) self-assembly has tremendous potential applications in next-generation nanolithography. It offers significant advantages, including high resolution and cost-effectiveness, effectively overcoming the limitations associated with conventional optical lithography. In this work, we demonstrate a focused solar annealing (FSA) technique that is facile, eco-friendly, and energy-efficient for fast self-assembly of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) thin films. The FSA principle involves utilizing a common biconvex lens to converge incident solar radiation into a high-temperature spot, which is directly used to drive the microphase separation of PS-b-PMMA thin films. As a result, PS-b-PMMA undergoes self-assembly, forming ordered nanostructures in a vertical orientation at seconds timescales on silicon substrates with a neutral layer. In addition, the FSA technique can be employed for grafting neutral polymer brushes onto the silicon substrate. Furthermore, the FSA's compatibility with graphoepitaxy-directed self-assembly (DSA) of BCP is also demonstrated in the patterning of contact holes. The results of contact hole shrinking show that contact hole prepatterns of ∼60.4 nm could be uniformly shrunk to ∼20.5 nm DSA hole patterns with a hole open yield (HOY) of 100 %. For contact hole multiplication, doublet DSA holes were successfully generated on elliptical templates, revealing an average DSA hole size of ∼21.3 nm. Most importantly, due to the direct use of solar energy, the FSA technique provides many significant advantages such as simplicity, environmental friendliness, solvent-free, low cost, and net-zero carbon emissions, and will open up a new direction for BCP lithography that is sustainable, pollution-free, and carbon-neutral.
... Kulkarni and Rao (2016) [9] evaluated the greenhouse gas emissions associated with the manufacturing of fired clay bricks. Hasanbegi et al. (2016) [10] performed a comparative study of the carbon footprint of steel production in three different countries: China, Germany, and Mexico. Venkataraman Reddy (2009) [11], in his review paper pertaining to energy, carbon emissions, and sustainability of building construction with particular reference to the Indian construction industry, emphasized the use of sustainable natural materials. ...
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Houses in villages that are traditionally built with locally available materials like wood, mud, and stones are nowadays being demolished and reconstructed. The current trend has been to adopt framed construction with reinforced cement concrete and red bricks as the main materials. This is going to have a significant environmental impact and needs to be addressed with critical observations. This study is conducted for a local village in Tripura state, India, where a new house for the economically weaker section was constructed using stabilized mud blocks and bamboo as a model house. The main objective is to investigate the environmental impact of the transformation of a traditional house constructed out of locally available materials versus masonry and concrete houses. The impact has been represented as the difference in the Carbon footprint of the two houses based on the LCA approach. It was found that the total carbon footprint of the house built with locally available bamboo and stabilized mud bricks is 9.599 tons, 11.736 tons, and 11.401 tons lower in landfilling, waste treatment, and circular economy, respectively, as compared to concrete and masonry houses, and it has the potential to reduce the impact of the production stage to be negative.
... Recent material flow analysis quantified detailed process-and route-specific emissions, which showed a considerable slowdown in energy efficiency improvement in the global steel industry since the 1990s 11 . However, comprehensive global estimates of steel-related emissions and their cost-effective mitigations for individual iron-and steel-producing facilities are still lacking [17][18][19][20][21][22][23][24][25] . ...
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The critical role of the iron and steel industry in decarbonizing global energy systems calls for refined strategies of climate mitigation. Here, based on a newly developed database of individual iron and steel facilities worldwide, we explore the distinct differences in age-to-capacity ratio and emissions intensity of primary steelmaking plants. We customize regional cost-effective decarbonization strategies by targeting a certain proportion of plants. We find that the more effective indicator for targeted decarbonization in developing regions is emissions intensity, while for developed countries it is age-to-capacity ratio. Whichever indicator we use to target plants, the strategy of transformation towards secondary steelmaking is generally more cost-effective than efficiency improvement in most cases, although obvious regional priorities exist. Our results emphasize the region-specific priorities of mitigation indicators and strategies in targeting plants, which help with designing short-term, cost-effective strategies for reducing steel-related CO2 emissions.
... Next, for each identified hotspot, the sourcing and manufacturing processes are considered to allocate the emissions to the correct sectors. For steel, most emissions occur due to the reduction process with coking coal in the industry sector (Bataille et al., 2021;WBCSD WRI, 2004;Hasanbeigi et al., 2016;Schimmel et al., Achtelik). Nevertheless, the use of hydrogen or electric arc furnaces can lead to a shift. ...
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Climate models and decarbonization scenarios use carbon budgets to distribute emission allowances and derive reduction targets for sectoral developments to limit global warming. These requirements are often not aligned with corporate climate targets due to missing targeting approaches for sectors and scopes as well as differences between absolute and intensity targets. Therefore, the aim of this paper is the development of an allocation scheme by combining frameworks for CO2eq accounting like the ISO 14040, the Greenhouse Gas Protocol and the IPCC Guidelines for inventory accounting to link sectoral carbon budgets to stages of product life cycles and vice versa. To calculate carbon budgets and reduction targets, a case study for the automotive industry is conducted. Consequently, average data sets of emission reporting, studies and LCAs for material compositions, forecasts on vehicles sales and the shares of electrified products are used. Depending on the applied decarbonization scenarios, different reduction trajectories aligned with pathways to limit global warming well below 2 °C and respectively to 1.5 °C are determined. As a result, the company has to reduce their absolute emissions from 2019 to 2030 by −25% to −46% equal to an intensity target of −32% to −51%.
... As the result of rapid economic development and urbanisation, China has been the world's largest steel producer and consumer. The production of crude steel in China accounts for around 50% of the whole world's production [33,34]. Steel slag (SS) is produced as the nonmetallic co-product of steel production, and the discharge and storage of SS cause severe environmental problems. ...
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Calcium sulfoaluminate (CSA) cement is recognized as an environmentally friendly alternative to Portland cement (PC) due to its lower carbon footprint and energy requirements. However, traditional CSA cement production faces significant obstacles, including the high cost and regionally constrained availability of bauxite, a key raw material. Utilizing alternative materials in the production process offers a viable approach to address these limitations. This study evaluated the environmental performance of three laboratory-synthesized CSA cements using alternative raw materials sourced through an industrial symbiosis framework. A comparative assessment with PC was conducted, focusing on energy consumption and CO2 emissions as key environmental performance indicators. The environmental impact of the CSA cements was analyzed using Monte Carlo simulations, a robust statistical approach based on data for the constituent raw materials. This method provides a practical alternative to a full life cycle assessment (LCA) when comprehensive data are not available. The results demonstrate that the CSA cements have significantly lower environmental impacts compared to PC, achieving energy savings of 13–16% and CO2 emission reductions of 35–48%. These results emphasize the potential of industrial symbiosis to enable more sustainable CSA cement production while addressing raw material constraints. In addition, this approach highlights the wider applicability of industrial symbiosis frameworks in the construction industry, contributing to a zero-waste future and supporting global climate goals.
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Houses in villages that are traditionally built with locally available materials like wood, mud, and stones are nowadays being demolished and reconstructed. The current trend has been to adopt framed construction with reinforced cement concrete and red bricks as the main materials. This is going to have a significant environmental impact and needs to be addressed with critical observations. This study was conducted for a local village in Tripura state, India, where a new house for the economically weaker section was constructed using stabilized mud blocks and bamboo as a model house. The main objective was to investigate the environmental impact of the transformation of a traditional house constructed out of locally available materials versus masonry and concrete houses. The impact has been represented as the difference in the Carbon footprint of the two houses based on the LCA approach. It was found that the total carbon footprint of the house built with locally available bamboo and stabilized mud bricks having a built up area of 25 m2 was 9.599 tons, 11.736 tons, and 11.401 tons of CO2 eq lower in landfilling, waste treatment and circular economy, respectively, as compared to concrete and masonry houses, and it has the potential to reduce the life cycle impact of the production stage to be almost neutral.
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Nature provides diverse services to humanity, known as ecosystem services (ES), yet certain services, such as food and timber, are geographically distant from human settlements. This spatial separation of ES from supply area to demand site fosters transfer through human-made carrier as ES flow, resulting in social and ecological impacts. This study delves into this complex ES supply, flow, and demand relation. While the conventional ES assessment approach mainly quantifies ES supply potential, Resources Time Footprint (RTF) is introduced as a new indicator to evaluate human intervention part of ES supply and flow. RTF examines intergenerational sustainability of ES by evaluating material, land, labor, and pollutant resource utilization in relation to individual allocations. The efficacy of this integration is evaluated through a case study covering 17 ESs dynamics in central Bhutan for 2010 and 2020, and RTF is applied to potato-ES, given its higher human intervention in the area. This is finally validated against commonly used emergy analysis and its derivatives. The study observed a 3.5% increase in 17 ESs, with minor intergenerational implications associated with supply and flow of potato-ES. The average per capita RTF values were 0.81 and 0.52 years, or 2 and 1.3 years per 100 kg of potatoes for the 2010 and 2020 base case, respectively. This smaller RTF value for 2020 indicates reduced resource occupancy rates with higher intergenerational sustainability. This replicable indicator effectively evaluated human related impacts on ES supply and flow and identified land and labor as underperforming aspects with higher occupancy rates. The comparative validation showed inadequateness of emergy-derivatives in examining human intervention in ES flow, and limitations of ES-RTF in evaluating nature's contribution. This underscores the complementary nature of two methodologies. Overall, this study contributes to a telecoupling framework for a sustainable society, enhancing coherence and consistency in analyzing ES supply and flow.
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The highly energy-intensive iron and steel industry contributed about 25% (ref. ¹) of global industrial CO2 emissions in 2019 and is therefore critical for climate-change mitigation. Despite discussions of decarbonization potentials at national and global levels2–6, plant-specific mitigation potentials and technologically driven pathways remain unclear, which cumulatively determines the progress of net-zero transition of the global iron and steel sector. Here we develop a CO2 emissions inventory of 4,883 individual iron and steel plants along with their technical characteristics, including processing routes and operating details (status, age, operation-years etc.). We identify and match appropriate emission-removal or zero-emission technologies to specific possessing routes, or what we define thereafter as a techno-specific decarbonization road map for every plant. We find that 57% of global plants have 8–24 operational years, which is the retrofitting window for low-carbon technologies. Low-carbon retrofitting following the operational characteristics of plants is key for limiting warming to 2 °C, whereas advanced retrofitting may help limit warming to 1.5 °C. If each plant were retrofitted 5 years earlier than the planned retrofitting schedule, this could lead to cumulative global emissions reductions of 69.6 (±52%) gigatonnes (Gt) CO2 from 2020 to 2050, almost double that of global CO2 emissions in 2021. Our results provide a detailed picture of CO2 emission patterns associated with production processing of iron and steel plants, illustrating the decarbonization pathway to the net-zero-emissions target with the efforts from each plant.
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The need for alternative construction materials that are both economically and environmentally sustainable cannot be overemphasised. Factors such as rising construction cost, high cost of urban land, and lack of affordable housing finance have made it almost impossible for low and average income earners in developing countries to afford decent housing. Conventional construction materials like reinforced concrete are expensive due to importation of reinforcement steel that is unavailable locally. Furthermore, the energy-intensiveness and high carbon footprint resulting from the manufacturing procedures and transportation of steel has necessitated the need for sustainable and affordable alternative construction materials. Hence the aim of this study is to develop a novel, affordable, and sustainable natural reinforcement for concrete from oil palm broom fibres (OPBF), which are the ribs of the leaflets of the oil palm tree (Elaeis guineensis). Until recently, OPBF were considered a waste and sometimes used as cooking fuel in rural areas or at best for making broom bristles due to its perceived stiffness and durability but without any information on its morphology, physical, and mechanical properties. To achieve this aim, an engineering characterisation of the OPBF was carried out which revealed that the fibres were superior to steel in terms of strength/weight ratio. Investigations into the use of the OPBF in concrete either as discrete randomly distributed reinforcement or as main longitudinal reinforcement were then carried out. In order to overcome the durability challenges associated with natural fibres, a treatment study aimed at improving the bond, physical and mechanical properties of OPBF was also carried out. The study revealed that thermal or chemical treatments were most appropriate for OPBF used as discrete randomly distributed fibres in concrete (OPBF-concrete). For its use as longitudinal reinforcement, steel hose clamps were employed to combine the individual fibres into strand units for the reinforcement of concrete beams (OPBF-reinforced concrete). While Response Surface Models were developed to predict the mechanical properties of OPBF-concrete for up to 112 days, Finite Element Modelling was employed for OPBF-reinforced concrete based on the constitutive relationships derived from the experimental investigations. The Finite Element study also investigated the effect of different parameters on the behaviour of the developed OPBF-reinforced concrete. Finally, design guidance and recommendations were made for which ultimate and serviceability limit states are satisfied. The main conclusion is that the developed natural fibre reinforced concrete can be used for affordable and sustainable housing construction across the world, particularly in developing countries. Keywords: Oil Palm Broom Fibres, Strands, Mechanical properties, Constitutive models, Concrete Damage Plasticity, Tensile strength, ABAQUS, Sustainable construction materials, OPBF-reinforced concrete.
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Wind power is a promising renewable energy source that is rapidly expanding in the global electricity mix. This study explored suitable locations for onshore wind turbines, and estimated the wind power potential in Fujian Province, China. We also analyzed the resource occupancy of 100 years of potential wind turbine operation in terms of the materials, CO2 emissions, land, and labor. This was done using the sustainability indicator – resources time footprint (RTF). RTF measures the ratio of the occupancy of the resource within a period of time to the total capacity to provide a product or service. This is done using a time dimension (years). A higher RTF value indicates a larger environmental and social impact. Fujian Province has an annual wind power potential of 50,638 GWh, which is mainly clustered around its coastal regions. The RTF of steel is the largest in the material aspect, which is 1.2 times that of copper and 23.9 times that of aluminum. Negative values of the RTF of CO2 and land show that wind power is conducive to CO2 emission reduction and the prevention of future land occupancy. Furthermore, the construction and operation of wind turbines will not impose a burden on the labor force. The RTF values of the wind turbines decreased with an increase in the annual average wind speed. By modifying the parameters, this methodology can be applied to determine ideal locations in other regions, which present the highest environmental benefits, for future wind turbine installations.
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Energy saving and emissions reduction in the iron and steel industry is a significant challenge to achieve carbon neutrality and sustainable development. Many studies focus on the optimization of materials, energy and carbon emissions but lack of optimization strategies in the iron and steel industry. A comprehensive and effective system model is still needed to optimize the CO2 emissions to face the production planning of a company in the future. This article applies industrial metabolism to develop a practical optimization model for improving materials consumption and energy consumption in coking, sintering, pelleting, ironmaking and steelmaking, and the minimum carbon emission is set as the optimization objective. The results show that carbon emissions reduce 148.65 kg/ton crude steel compared with the original data with a yield of 8.4 Mt crude steel. In addition, the optimum material and energy consumption of each production unit under different production plans is studied. If breakthrough technologies are not applied to long-route processes, improving scrap steel ratio is the most promising approach for low-carbon manufacturing in the iron and steel industry in the future.
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To clarify the influence factors and optimization direction of energy consumption of EAF steelmaking, this study established a complete mass and energy balance model, comprising infiltrated air and off-gas flowrate measurement model and radiative and convective heat loss model, to forecast power and oxygen consumption. The influence of power supply, oxygen supply, carbon injection, infiltrated air, and hot metal charging on the power consumption of EAF is discussed. The results show that optimizing production parameters will effectively reduce power consumption, especially improve the infiltrated air flowrate when there are sufficient combustible gases, which is conducive to energy conservation and emission reduction. Additionally, due to the intensive energy and carbon input in the upstream process of hot metal production, the energy consumption and carbon emissions of hot metal charging EAF are much higher than those of 100% scrap charging EAF.
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Energy consumption of the iron and steel industry is examined in seven countries (Brazil, China, France, Germany, Japan, Poland and the United States) for the period 1980–1991. Using a decomposition analysis based on physical indicators for process type and product mix, we decompose intra-sectoral structural changes and efficiency improvements. Specific energy consumption decreased in all countries except Poland. Efficiency improvement played a key role in Brazil, China, Germany and the US, while structural changes were the main driver for energy savings in France and Japan. We also compare the use of various economic indicators to physical indicators and find that they do not track physical developments well in Poland or the developing countries we studied. In the industrialized countries, value added based energy intensity indicators generally reflect the specific energy consumption better than other economic indicators, although large differences occur in individual years. We found a smaller correlation between other economic indicators (gross output and value of shipments) and specific energy consumption. We conclude that use of physical energy intensity indicators improves comparability between countries, provides greater information for policy-makers regarding intra-sectoral structural changes, and provides detailed explanations for observed changes in energy intensity.
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Market-based climate change policy instruments have frequently been proposed as efficient means to stimulate industrial energy efficiency improvements and to reduce carbon emissions. This paper presents an assessment of the impacts that energy taxes and policies that increase cost of carbon may have on energy use and emission profiles of the US iron and steel industry. Time series data and engineering information are combined to endogenously specify changes in technologies, fuel mix, and production processes within a dynamic computer model. The results of the model indicate that energy taxes are likely to shift a slightly larger share of production to the electric arc furnace route and reduce total energy use more than combarable climate change policies that raise costs of carbon. However, both energy taxes and costs of carbon will result in a similar decrease in carbon emissions when compared to the absence of those policies.
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A model of the EAF energy efficiency was developed based on a closed mass and energy balance of the EAF melting process. This model was applied to industrial EAFs in steel industry charged with scrap or with mixes of scrap and DRI. Complex mass and energy conversion in the EAF was simplified with the introduction of mass and energy conversion efficiencies for the conversion of oxygen and the energy conversion of electrical energy in the electric arcs, chemical energy from the oxidation reactions in the melt and energy from the combustion of burner gas. It turned out that close agreement with observed process parameters from 16 EAFs is obtained by slight variations of the efficiency values. Especially the sensitivity of the steel temperature from the energy conversion efficiency of the electric arc energy indicates the importance of efficient foaming slag operation in EAF steel making. Characteristics and process parameters of DRI charged EAFs are discussed. Model results for a series of case studies illustrate the correlations between DRI chemical composition, DRI portion, oxygen consumption, etc. with electrical energy demand in order to indentify cost-effective EAF process conditions.
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Ferroalloys are defined as iron-bearing alloys with a high proportion of one or more other elements – manganese, chromium, silicon, molybdenum, etc., mainly used by the iron and steel industries. Life cycle assessment methodology was used to estimate the greenhouse gas (GHG) footprint of a number of these ferroalloy production processes. The results of the study showed that GHG footprint for ferroalloy production in Australia was 1.8 t CO2e/t FeMn, 2.8 t CO2e/t SiMn and 3.4 t CO2e/t FeSi alloy metal. These results compare with GHG footprints for ferronickel and ferrochromium of 13.9 t CO2e/t and 3.0 t CO2e/t, respectively revised from an earlier study. These GHG footprint estimates were calculated using the Tasmanian electricity greenhouse gas emission factor since these ferroalloy industries are located in Tasmania, Australia. The major difference in greenhouse gas emissions between the various ferroalloys is largely due to their respective amounts of electricity use and coke/coal consumption. These results are not too different to the results from a limited number of studies reported in the literature when compared on a similar electricity source basis. The LCA results also showed that coke and coal usage contributed close to 60% or more of the total GHG emissions from the various ferroalloy production processes. In light of this finding, there would appear to be an opportunity to reduce GHG emissions from ferroalloy production if fossil fuel-based coal is replaced with biomass based renewable carbon.
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The goal of this study was to develop a methodology for making an accurate comparison of the energy intensity of steel production in China and the U.S. Such values are often sought by policy-makers when making decisions related to energy, greenhouse gases, and competitiveness. The methodology addresses issues related to boundary definitions, conversion factors, and technology structure. In addition to the base case analysis, four sensitivity and two factor analyses were developed to assess the effect of different factors on energy intensities. The results of the analysis show that for the whole iron and steel production process, the final energy intensity in 2006 was equal to 14.90 GJ/t crude steel in the U.S. and 23.11 GJ/t crude steel in China in the base-case analysis. In another factor analysis that assumed the Chinese share of electric arc furnace production in 2006 (10.5%) in the U.S., the energy intensity of steel production in the U.S. increased by 54% to 22.96 GJ/t crude steel. This result highlights the fact that when comparing the energy intensity of the U.S and Chinese steel industry, the technology structure, especially the share of electric arc furnace should be taken into account. A number of policy implications are also discussed.
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The iron and steel sector is the largest industrial CO2 emitter and energy consumer in the world. Energy efficiency is key to reduce energy consumption and GHG emissions. To understand future developments of energy use in the steel sector, it is worthwhile to analyze energy efficiency developments over the past two decades. This paper analyses the development of the specific energy consumption (SEC) (measured as primary energy use per unit of product) in the German steel sector between 1991 and 2007.We found that the total SEC declined by 0.4%/year. Of this 75%, or 0.3%/year, is due to a structural change towards more electric arc furnaces (EAF). Energy efficiency improvement accounts for about 25% of the observed change in SEC, or 0.1%/year. Energy efficiency improvements are found, especially in rolling (1.4%/year). The net SEC of blast furnaces decreased due to increased top gas recovery by 0.2%/year per tonne iron. Improvements in other processes were very limited or non-existent. In basic oxygen furnaces (BOF) net SEC increased due to a 60% decrease in BOF gas recovery between 1993 and 2007. In EAF and sinter plants the SEC remained constant or, respectively, even increased by 9% between 1991 and 2007 per tonne sinter.
Article
The U.S. steel industry has taken enormous strides over the past decades to reduce its energy consumption; since the end of World War II, the industry has reduced its energy intensity (energy use per shipped ton) by 60 percent. Between 1990 and 1998 alone, intensity has dropped from 20 to 18 million Btu (MBtu) per ton. This figure is projected to decrease to 15 MBtu/ton by 2010 with an asymptotic trend towards 14 MBtu/ton. Domestic shipments are projected to flatten out over the next decade to around 105 million tons which means that total energy consumption will also decrease. Historically, the steel industry has accounted for about 6 percent of U.S. energy consumption. Today, that figure is less than 2 percent and will decrease further to 1.5 percent by 2010. The primary causes for the decrease in energy consumption since WWII are: The use of pellets in the blast furnace and the application of new technology in the ironmaking process to further reduce fuel rates per net ton of hot metal (NTHM); The total replacement of the open hearth process by basic oxygen and electric furnaces; The almost total replacement of ingot casting by continuous casting (which improved yield dramatically and thus reduced the tons of raw steel required per ton of shipments); and The growth of the electric furnace sector of the industry at the expense of hot metal-based processes (which has also stimulated scrap recycling so that about 55 percent of ''new'' steel is now melted from scrap steel). This report focuses on the concept of good practices (i.e., those that are sustainable and can use today's technology). If all the industry could operate on this basis, the additional savings per ton could total 2 MBtu, As further restructuring occurs and the swing from hot metal-based to electric furnace-based production continues, the average consumption will approach the good practice energy per ton. Further savings will accrue through new technology, particularly in the areas of reduced blast furnace fuel rates and reheating efficiency, both of which relate to large tonnages of material.
Article
Ironmaking involves the separation of iron ores. It not only represents the first step in steelmaking but also is the most capital-intensive and energy-intensive process in the production of steel. The main route for producing iron for steelmaking is to use the blast furnace, which uses metallurgical coke as the reductant. Concerns over the limited resources, the high cost of coking coals, and the environmental impacts of coking and sinter plants have driven steelmakers to develop alternative ironmaking processes that can use non-coking coals to reduce iron ores directly. Since the efficiency and productivity of modern large capacity blast furnaces will be difficult to surpass, blast furnaces will continue to retain their predominant position as the foremost ironmaking process for some time to come. The alternative ironmaking processes are therefore expected to play an increasingly significant role in the iron and steel industry, especially in meeting the needs of small-sized local and regional markets. It is likely that the importance of direct reduced iron (DRI) and hot metal as sources of virgin iron will continue to increase, especially in the developing countries where steelmaking is, and will be, primarily based on electric arc furnace (EAF) minimills. Consequently, the challenges that are faced by the new technology have to be embraced.
Article
Die Stahlindustrie in Deutschland gehört aufgrund des Reduktionsmittelbedarfs an Kohlenstoff für ihre metallurgischen Stoffumwandlungsprozesse und ihrer hohen Erzeugungsmenge von rd. 45 Mio. t Rohstahl pro Jahr zu den energieintensiven CO2-emittierenden Branchen. Sie hat sich gegenüber der Bundesregierung verpflichtet, ihre spezifischen Kohlendioxid-Emissionen bis zum Jahr 2012 um 22 Prozent gegenüber dem Referenzjahr 1990 zu verringern. Maßnahmen zur Verringerung der CO2-Emissionen beziehen sich auf die Erhöhung der Energie- und Ressourceneffizienz. Viel versprechende neue Anstze mit erheblichem CO2-Minderungspotenzial bietet die Weiterverarbeitung von Rohstahl zu Walzstahl. Zukunftstechnologien und langfristige Maßnahmen für die Klimavorsorge stellen die Wasserstofftechnologie zur Roheisen- und Stahlerzeugung sowie die Hochtemperaturelektrolyse von Eisenerz mit CO2-unbelasteter elektrischer Energie dar. Innerhalb der Wertschöpfungsketten tragen neue Stahlwerkstoffe zu einer weiteren Verminderung von CO2-Emissionen bei.
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Energy efficiency improvement is a basic yet significant way of addressing both energy security and environment concerns. There are various measures of industrial energy efficiency performance, with different purposes and applications. This paper explores different ways to measure energy efficiency performance (MEEP): absolute energy consumption, energy intensity, diffusion of specific energy-saving technology and thermal efficiency. It discusses their advantages and disadvantages, and roles within policy frameworks. Policy makers should consider the suitability of MEEP based on criteria such as reliability, feasibility and verifiability. The limitations of both energy intensity and necessity of broader all-inclusive indicators and technology diffusion indicators are also discussed. A case study on Japan's iron and steel industry illustrates the critical role of proper boundary definitions for a meaningful assessment of energy efficiency in industry. Depending on the boundaries set for the analysis, the energy consumption per ton of crude steel ranges from 16 to 21 GJ. This paper stresses the importance of a proper understanding of various methods to assess energy efficiency, and the linkage with policy objectives and frameworks. Possible next steps for improvement of MEEP, such as database development, were also discussed.
Article
We develop calibrated models of energy and material consumption patterns in the US steel industry, starting with an energy end-use model based on 1994 Manufacturing Energy Consumption Survey (MECS) data. Then process-step models of material and energy use are developed and calibrated against the energy end-use model and data from the US Commerce Department and the American Iron and Steel Institute. These models can serve as benchmarks for current steelmaking operations and as base cases for simulating changes in steelmaking energy utilization and waste streams spurred by economics, regulations, or technology innovations.
Article
During the seventies and eighties the US steel industry received trade protection. However, these rents were not used to improve competitiveness. Instead, they were reflected in higher wages and a greater share of profits invested in sectors not related to steel. Moreover, the steel industry failed to adopt technological innovations on a timely basis and was displaced by the minimills. We rationalize these puzzling outcomes using a dynamic game between workers and firms.
Article
The pollution-convergence hypothesis is formalized in a neoclassical growth model with optimal emissions reduction: pollution growth rates are positively correlated with output growth (scale effect) but negatively correlated with emission levels (defensive effect). This dynamic law is empirically tested for two major and regulated air pollutants - nitrogen oxides (NOX) and sulfur oxides (SOX) - with a panel of 25 European countries spanning over years 1980-2005. Traditional parametric models are rejected by the data. However, more flexible regression techniques - semiparametric additive specifications and fully nonparametric regressions with discrete and continuous factors - confirm the existence of the predicted positive and defensive effects. By analyzing the spatial distributions of per capita emissions, we also show that cross-country pollution gaps have decreased over the period for both pollutants and within the Eastern as well as the Western European areas. A Markov modeling approach predicts further cross-country absolute convergence, in particular for SOX. The latter results hold in the presence of spatial non-convergence in per capita income levels within both regions.
Article
International comparison of energy intensity is receiving increased scientific and political attention. International comparisons may help in identifying the potentials for energy intensity reduction. Knowledge of these reduction potentials can be used as the basis of national policies to reduce energy intensity, and also for designing international actions to curb the threats of climate change. Although we showed in a previous paper that indicators based on physical production data are well suited for international comparison of energy intensity, many potential problems exist regarding the availability and quality of energy and production data needed for such indicators. We studied these data problems for physical energy intensity indicators for the iron and steel industry. We started by comparing the energy data from four international data sources. It turned out that quite some mistakes are made in the reported energy data, which makes reliable international comparison of countries difficult. The available production data, and the methodology of using physical production indicators, turned out to be less problematic. We found that the accuracy of physical energy intensity indicators is, to a large extent, determined by the accuracy of the energy consumption data used. We recommend that energy analysts be careful in using energy data for international comparisons. We also recommend that national and international statistical organizations put more effort in assuring the quality of the energy consumption data in their publications.
National Energy Balance of 2012. SENER (in Spanish)
  • Energía Secretaría De
Secretaría de Energía (SENER), 2012. National Energy Balance of 2012. SENER (in Spanish).
Prospectiva Del Sector Eléctrico
  • Sener
SENER, 2014. Prospectiva Del Sector Eléctrico 2013-2027. SENER (in Spanish).
Entwicklung der spezifischen Kohlendioxid-Emissionen des deutschen Strommix 1990-2010 und erste Schätzungen
  • Umweltbundesamt
Umweltbundesamt (UBA) (2012). Entwicklung der spezifischen Kohlendioxid-Emissionen des deutschen Strommix 1990-2010 und erste Schätzungen 2011 (in German).
CO2 Emissions Data Collection −User Guide
  • D Worldsteel N
worldsteel n.d., CO2 Emissions Data Collection −User Guide, Version 6, http:// www.worldsteel.org/climatechange/files/2/2/ Data%20collection%20user%20guide.pdf.