The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Tetsuya Nagasaka - One of the best experts on this subject based on the ideXlab platform.
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toward the efficient recycling of alloying elements from end of life vehicle steel scrap
Resources Conservation and Recycling, 2015Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Abstract There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel Materials, including alloy steels that contain alloying elements (AEs) such as manganese, chromium, nickel, and molybdenum, are the main component of automobiles. The recycling of end-of-life vehicles (ELVs) significantly affects the cycling of iron, steel, and AEs. Currently, ELV recycling is performed using the electric arc furnace (EAF). In this method, losses of AEs are likely to occur because their presence is rarely considered. This study evaluated the environmental and economic benefits of alternative ELV recycling schemes, which allow more efficient utilization of AEs found in ELV-derived steel scrap (ELV-dSS). The AE contents in ELV-dSS (as car-parts) were estimated by means of a waste input–Output Material flow analysis (WIO-MFA) model extended for the detailed analysis of automobile composition. Using Japanese data, it was found that sorting ELV-dSS by parts can result in a significant recovery of AEs; more specifically, a 10-fold saving in AEs was achieved by sorting exhaust parts. The recoverable mass of AEs from sorted ELV-dSS was found to correspond to 8.2% of the annual consumption of AEs in Japan, as virgin resources in EAF steelmaking. ELV-dSS sorting was found to be significantly effective in the conservation of AE resources.
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unintentional flow of alloying elements in steel during recycling of end of life vehicles
Journal of Industrial Ecology, 2014Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Alloying elements in steel add a wide range of valuable properties to steel Materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-Output Material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel Materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous Materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.
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simultaneous Material flow analysis of nickel chromium and molybdenum used in alloy steel by means of input Output analysis
Environmental Science & Technology, 2013Co-Authors: Kenichi Nakajima, Hajime Ohno, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Osamu Takeda, Takahiro Miki, Tetsuya NagasakaAbstract:Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or Material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of Materials/substances in supply chains. This study combined a waste input–Output Material flow model and physical unit input–Output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Im...
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Identifying the Substance Flow of Metals Embedded in Japanese International Trade by Use of Waste Input-Output Material Flow Analysis (WIO-MFA) Model
Isij International, 2011Co-Authors: Kenichi Nakajima, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Keisuke Nansai, Shigemi Kagawa, Rokuta Inaba, Tetsuya NagasakaAbstract:This study proposes a method of combining a waste input–Output Material flow analysis (WIO-MFA) model with trade statistical data to identify the flows of substances embedded in trade commodities. We focused on the case of Japan as a typical processing and trading country, and we estimated each mass of iron and aluminum embedded in the imports and exports of 300 product items categorized in the WIO-MFA. We found that iron ore imported from Australia, Brazil, and India as a raw Material is processed and exported to South Korea, China, and other Asian countries as steel Materials and to the United States as steel Materials and automobiles. Primary aluminum imported from Russia, Australia, and Brazil as a raw Material is processed and exported to Asia as rolled Materials and to the United States as rolled Materials and automobiles.
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analyzing polyvinyl chloride in japan with the waste input Output Material flow analysis model
Journal of Industrial Ecology, 2009Co-Authors: Shinichiro Nakamura, Kenichi Nakajima, Yoshie Yoshizawa, Kazuyo Matsubaeyokoyama, Tetsuya NagasakaAbstract:Summary Effective life cycle management of polyvinyl chloride (PVC) calls for the separation of end-of-life PVC products at the time of collection not only from other wastes but among different PVC types as well. Information about the flow of PVC products in the economy is important for this purpose. Within the framework of the Japanese input−Output (IO) table for the year 2000, with around 400 industry sectors, the flow of PVC is captured in terms of six PVC-embodying products and in terms of three PVC types, (1) flexible PVC (soft PVC), (2) rigid PVC (hard PVC), and (3) others. The degree of resolution; the consideration of different PVC types, which are seldom performed in the Material flow analysis (MFA) literature; and the use of waste input−Output Material flow analysis (WIO-MFA) represent distinguishing features of our study. The use of WIO-MFA methodology enables one to convert a monetary input−Output table into a physical interindustry flow table involving an arbitrary number of Materials under full consideration of the mass balance. The results indicate that 40% of the PVC produced in Japan is exported (as resins and as products such as passenger motor cars), and the rest is accumulated mostly as capital stock. The largest share of accumulation goes to public construction in the form of plates, pipes, and bars, which are mostly hard-PVC products.
Shinichiro Nakamura - One of the best experts on this subject based on the ideXlab platform.
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toward the efficient recycling of alloying elements from end of life vehicle steel scrap
Resources Conservation and Recycling, 2015Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Abstract There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel Materials, including alloy steels that contain alloying elements (AEs) such as manganese, chromium, nickel, and molybdenum, are the main component of automobiles. The recycling of end-of-life vehicles (ELVs) significantly affects the cycling of iron, steel, and AEs. Currently, ELV recycling is performed using the electric arc furnace (EAF). In this method, losses of AEs are likely to occur because their presence is rarely considered. This study evaluated the environmental and economic benefits of alternative ELV recycling schemes, which allow more efficient utilization of AEs found in ELV-derived steel scrap (ELV-dSS). The AE contents in ELV-dSS (as car-parts) were estimated by means of a waste input–Output Material flow analysis (WIO-MFA) model extended for the detailed analysis of automobile composition. Using Japanese data, it was found that sorting ELV-dSS by parts can result in a significant recovery of AEs; more specifically, a 10-fold saving in AEs was achieved by sorting exhaust parts. The recoverable mass of AEs from sorted ELV-dSS was found to correspond to 8.2% of the annual consumption of AEs in Japan, as virgin resources in EAF steelmaking. ELV-dSS sorting was found to be significantly effective in the conservation of AE resources.
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unintentional flow of alloying elements in steel during recycling of end of life vehicles
Journal of Industrial Ecology, 2014Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Alloying elements in steel add a wide range of valuable properties to steel Materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-Output Material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel Materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous Materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.
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simultaneous Material flow analysis of nickel chromium and molybdenum used in alloy steel by means of input Output analysis
Environmental Science & Technology, 2013Co-Authors: Kenichi Nakajima, Hajime Ohno, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Osamu Takeda, Takahiro Miki, Tetsuya NagasakaAbstract:Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or Material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of Materials/substances in supply chains. This study combined a waste input–Output Material flow model and physical unit input–Output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Im...
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The anatomy of capital stock : input-Output Material flow analysis (MFA) of the Material composition of physical stocks and its evolution over time
Revue de Métallurgie, 2012Co-Authors: Yasushi Kondo, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro NakamuraAbstract:The operation of an economy is supported by the stock of Materials in the form of durables and infrastructure such as machinery, equipment, buildings, and structures. The amount of durables and infrastructure or “capital stock” in the economy is of great interest in the literature of economics, and is usually measured in monetary terms based on the data on capital expenditure. In spite of its wide use by economists, this measure of “capital stock” is of very limited use for sustainable management of Material stock because of its neglect of physical properties such as the mass and Material composition. This paper proposes a new method of measuring the stock of long-lived durables and infrastructure in terms of the mass of its Materials. This method is based on the WIO-MFA method [S. Nakamura et al. J . Ind . Ecol . 11 (2007) 50-63] and the capital formation matrix that is one of the supplementary tables of the input-Output table. The method is applied to the Japanese input-Output data with 400 sectors, with 9 types of metals (iron, ferroalloy, copper, zinc, lead, tin, aluminum, silver, and gold) and 8 types of plastics (thermo-setting resins, PE (low), PE (high), PS, PP, PVC, high-performance resins, and other resins) occurring as Materials. It was found that substantial variations exist among sectors while fixed capital formation in the year 2000 weighs 518 kg per million Japanese yen on average in metals and plastics.
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Identifying the Substance Flow of Metals Embedded in Japanese International Trade by Use of Waste Input-Output Material Flow Analysis (WIO-MFA) Model
Isij International, 2011Co-Authors: Kenichi Nakajima, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Keisuke Nansai, Shigemi Kagawa, Rokuta Inaba, Tetsuya NagasakaAbstract:This study proposes a method of combining a waste input–Output Material flow analysis (WIO-MFA) model with trade statistical data to identify the flows of substances embedded in trade commodities. We focused on the case of Japan as a typical processing and trading country, and we estimated each mass of iron and aluminum embedded in the imports and exports of 300 product items categorized in the WIO-MFA. We found that iron ore imported from Australia, Brazil, and India as a raw Material is processed and exported to South Korea, China, and other Asian countries as steel Materials and to the United States as steel Materials and automobiles. Primary aluminum imported from Russia, Australia, and Brazil as a raw Material is processed and exported to Asia as rolled Materials and to the United States as rolled Materials and automobiles.
Kenichi Nakajima - One of the best experts on this subject based on the ideXlab platform.
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toward the efficient recycling of alloying elements from end of life vehicle steel scrap
Resources Conservation and Recycling, 2015Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Abstract There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel Materials, including alloy steels that contain alloying elements (AEs) such as manganese, chromium, nickel, and molybdenum, are the main component of automobiles. The recycling of end-of-life vehicles (ELVs) significantly affects the cycling of iron, steel, and AEs. Currently, ELV recycling is performed using the electric arc furnace (EAF). In this method, losses of AEs are likely to occur because their presence is rarely considered. This study evaluated the environmental and economic benefits of alternative ELV recycling schemes, which allow more efficient utilization of AEs found in ELV-derived steel scrap (ELV-dSS). The AE contents in ELV-dSS (as car-parts) were estimated by means of a waste input–Output Material flow analysis (WIO-MFA) model extended for the detailed analysis of automobile composition. Using Japanese data, it was found that sorting ELV-dSS by parts can result in a significant recovery of AEs; more specifically, a 10-fold saving in AEs was achieved by sorting exhaust parts. The recoverable mass of AEs from sorted ELV-dSS was found to correspond to 8.2% of the annual consumption of AEs in Japan, as virgin resources in EAF steelmaking. ELV-dSS sorting was found to be significantly effective in the conservation of AE resources.
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unintentional flow of alloying elements in steel during recycling of end of life vehicles
Journal of Industrial Ecology, 2014Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Alloying elements in steel add a wide range of valuable properties to steel Materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-Output Material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel Materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous Materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.
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DYNAMIC MODELING OF WORLD STEEL CYCLE TOWARD 2050
2013Co-Authors: Niina Fujitsuka, Kenichi Nakajima, Ichiro Daigo, Yoshikazu Goto, Yasunari MatsunoAbstract:In this work, a dynamic Material flow analysis (MFA) was conducted to estimate the global flow and in-use stock of steel for 42countries until 2010. The growth of the future in-use stock and demand of steel for three products (civil engineering, building, and vehicles) towards 2050 was also estimated under the concept of “stocks drive flows”, considering the economic and population growth in every country. In addition, we analyzed the steel scrap generation in each product and in every country up to 2050, and investigated the steel use potentials by using waste input-Output Material flow analysis (WIO-MFA).
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simultaneous Material flow analysis of nickel chromium and molybdenum used in alloy steel by means of input Output analysis
Environmental Science & Technology, 2013Co-Authors: Kenichi Nakajima, Hajime Ohno, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Osamu Takeda, Takahiro Miki, Tetsuya NagasakaAbstract:Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or Material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of Materials/substances in supply chains. This study combined a waste input–Output Material flow model and physical unit input–Output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Im...
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The anatomy of capital stock : input-Output Material flow analysis (MFA) of the Material composition of physical stocks and its evolution over time
Revue de Métallurgie, 2012Co-Authors: Yasushi Kondo, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro NakamuraAbstract:The operation of an economy is supported by the stock of Materials in the form of durables and infrastructure such as machinery, equipment, buildings, and structures. The amount of durables and infrastructure or “capital stock” in the economy is of great interest in the literature of economics, and is usually measured in monetary terms based on the data on capital expenditure. In spite of its wide use by economists, this measure of “capital stock” is of very limited use for sustainable management of Material stock because of its neglect of physical properties such as the mass and Material composition. This paper proposes a new method of measuring the stock of long-lived durables and infrastructure in terms of the mass of its Materials. This method is based on the WIO-MFA method [S. Nakamura et al. J . Ind . Ecol . 11 (2007) 50-63] and the capital formation matrix that is one of the supplementary tables of the input-Output table. The method is applied to the Japanese input-Output data with 400 sectors, with 9 types of metals (iron, ferroalloy, copper, zinc, lead, tin, aluminum, silver, and gold) and 8 types of plastics (thermo-setting resins, PE (low), PE (high), PS, PP, PVC, high-performance resins, and other resins) occurring as Materials. It was found that substantial variations exist among sectors while fixed capital formation in the year 2000 weighs 518 kg per million Japanese yen on average in metals and plastics.
Hajime Ohno - One of the best experts on this subject based on the ideXlab platform.
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Building the Material Flow Networks of Aluminum in the 2007 U.S. Economy
Environmental Science and Technology, 2016Co-Authors: Weiqiang Chen, Thomas E. Graedel, Philip Nuss, Hajime OhnoAbstract:Based on the combination of the U.S. economic input-Output table and the stocks and flows framework for characterizing anthropogenic metal cycles, this study presents a methodology for building Material flow networks of bulk metals in the U.S. economy and applies it to aluminum. The results, which we term the Input–Output Material Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow in the entire U.S. economy and for any chosen industrial sector (illustrated for the Automobile Manufacturing sector). The results are compared with information from our former study on U.S. aluminum stocks and flows to demonstrate the robustness and value of this new methodology. We find that the IO-MFN approach has the following advantages: (1) it helps to uncover the network of Material flows in the manufacturing stage in the life cycle of metals; (2) it provides a method that may be less time-consuming but more complete and accurate in estimating new scrap generation, process loss, domestic final demand, and trade of final products of metals, than existing Material flow analysis approaches; and, most importantly, (3) it enables the analysis of the Material flows of metals in the U.S. economy from a network perspective, rather than merely that of a life cycle chain.
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Building the Material Flow Networks of Aluminum in the 2007 U.S. Economy
Environmental science & technology, 2016Co-Authors: Weiqiang Chen, Thomas E. Graedel, Philip Nuss, Hajime OhnoAbstract:Based on the combination of the U.S. economic input-Output table and the stocks and flows framework for characterizing anthropogenic metal cycles, this study presents a methodology for building Material flow networks of bulk metals in the U.S. economy and applies it to aluminum. The results, which we term the Input–Output Material Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow in the entire U.S. economy and for any chosen industrial sector (illustrated for the Automobile Manufacturing sector). The results are compared with information from our former study on U.S. aluminum stocks and flows to demonstrate the robustness and value of this new methodology. We find that the IO-MFN approach has the following advantages: (1) it helps to uncover the network of Material flows in the manufacturing stage in the life cycle of metals; (2) it provides a method that may be less time-consuming but more complete and accurate in estimating new scrap generation, process loss, domestic final demand, an...
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toward the efficient recycling of alloying elements from end of life vehicle steel scrap
Resources Conservation and Recycling, 2015Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Abstract There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel Materials, including alloy steels that contain alloying elements (AEs) such as manganese, chromium, nickel, and molybdenum, are the main component of automobiles. The recycling of end-of-life vehicles (ELVs) significantly affects the cycling of iron, steel, and AEs. Currently, ELV recycling is performed using the electric arc furnace (EAF). In this method, losses of AEs are likely to occur because their presence is rarely considered. This study evaluated the environmental and economic benefits of alternative ELV recycling schemes, which allow more efficient utilization of AEs found in ELV-derived steel scrap (ELV-dSS). The AE contents in ELV-dSS (as car-parts) were estimated by means of a waste input–Output Material flow analysis (WIO-MFA) model extended for the detailed analysis of automobile composition. Using Japanese data, it was found that sorting ELV-dSS by parts can result in a significant recovery of AEs; more specifically, a 10-fold saving in AEs was achieved by sorting exhaust parts. The recoverable mass of AEs from sorted ELV-dSS was found to correspond to 8.2% of the annual consumption of AEs in Japan, as virgin resources in EAF steelmaking. ELV-dSS sorting was found to be significantly effective in the conservation of AE resources.
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unintentional flow of alloying elements in steel during recycling of end of life vehicles
Journal of Industrial Ecology, 2014Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Alloying elements in steel add a wide range of valuable properties to steel Materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-Output Material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel Materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous Materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.
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simultaneous Material flow analysis of nickel chromium and molybdenum used in alloy steel by means of input Output analysis
Environmental Science & Technology, 2013Co-Authors: Kenichi Nakajima, Hajime Ohno, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Osamu Takeda, Takahiro Miki, Tetsuya NagasakaAbstract:Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or Material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of Materials/substances in supply chains. This study combined a waste input–Output Material flow model and physical unit input–Output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Im...
Kazuyo Matsubae - One of the best experts on this subject based on the ideXlab platform.
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toward the efficient recycling of alloying elements from end of life vehicle steel scrap
Resources Conservation and Recycling, 2015Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Abstract There has been a sharp increase in the production of automobiles over the past decade. In 2010, one billion automobiles were in circulation worldwide. The automobile industry is one of the largest metals consumers and plays an important role in their sustainable use. Steel Materials, including alloy steels that contain alloying elements (AEs) such as manganese, chromium, nickel, and molybdenum, are the main component of automobiles. The recycling of end-of-life vehicles (ELVs) significantly affects the cycling of iron, steel, and AEs. Currently, ELV recycling is performed using the electric arc furnace (EAF). In this method, losses of AEs are likely to occur because their presence is rarely considered. This study evaluated the environmental and economic benefits of alternative ELV recycling schemes, which allow more efficient utilization of AEs found in ELV-derived steel scrap (ELV-dSS). The AE contents in ELV-dSS (as car-parts) were estimated by means of a waste input–Output Material flow analysis (WIO-MFA) model extended for the detailed analysis of automobile composition. Using Japanese data, it was found that sorting ELV-dSS by parts can result in a significant recovery of AEs; more specifically, a 10-fold saving in AEs was achieved by sorting exhaust parts. The recoverable mass of AEs from sorted ELV-dSS was found to correspond to 8.2% of the annual consumption of AEs in Japan, as virgin resources in EAF steelmaking. ELV-dSS sorting was found to be significantly effective in the conservation of AE resources.
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unintentional flow of alloying elements in steel during recycling of end of life vehicles
Journal of Industrial Ecology, 2014Co-Authors: Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya NagasakaAbstract:Alloying elements in steel add a wide range of valuable properties to steel Materials that are indispensable for the global economy. However, they are likely to be effectively irretrievably blended into the steel when recycled because of (among other issues) the lack of information about the composition of the scrap. This results in the alloying elements dissipating in slag during steelmaking and/or becoming contaminants in secondary steel. We used the waste input-Output Material flow analysis model to quantify the unintentional flows of alloying elements (i.e., chromium, nickel, and molybdenum) that occur in steel Materials and that result from mixing during end-of-life (EOL) processes. The model can be used to predict in detail the flows of ferrous Materials in various phases, including the recycling phase by extending steel, alloying element source, and iron and steel scrap sectors. Application of the model to Japanese data indicates the critical importance of the recycling of EOL vehicles (ELVs) in Japan because passenger cars are the final destination of the largest share of these alloying elements. However, the contents of alloying elements are rarely considered in current ELV recycling. Consequently, the present study demonstrates that considerable amounts of alloying elements, which correspond to 7% to 8% of the annual consumption in electric arc furnace (EAF) steelmaking, are unintentionally introduced into EAFs. This result suggests the importance of quality-based scrap recycling for efficient management of alloying elements.
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simultaneous Material flow analysis of nickel chromium and molybdenum used in alloy steel by means of input Output analysis
Environmental Science & Technology, 2013Co-Authors: Kenichi Nakajima, Hajime Ohno, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Osamu Takeda, Takahiro Miki, Tetsuya NagasakaAbstract:Steel is not elemental iron but rather a group of iron-based alloys containing many elements, especially chromium, nickel, and molybdenum. Steel recycling is expected to promote efficient resource use. However, open-loop recycling of steel could result in quality loss of nickel and molybdenum and/or Material loss of chromium. Knowledge about alloying element substance flow is needed to avoid such losses. Material flow analyses (MFAs) indicate the importance of steel recycling to recovery of alloying elements. Flows of nickel, chromium, and molybdenum are interconnected, but MFAs have paid little attention to the interconnected flow of Materials/substances in supply chains. This study combined a waste input–Output Material flow model and physical unit input–Output analysis to perform a simultaneous MFA for nickel, chromium, and molybdenum in the Japanese economy in 2000. Results indicated the importance of recovery of these elements in recycling policies for end-of-life (EoL) vehicles and constructions. Im...
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The anatomy of capital stock : input-Output Material flow analysis (MFA) of the Material composition of physical stocks and its evolution over time
Revue de Métallurgie, 2012Co-Authors: Yasushi Kondo, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro NakamuraAbstract:The operation of an economy is supported by the stock of Materials in the form of durables and infrastructure such as machinery, equipment, buildings, and structures. The amount of durables and infrastructure or “capital stock” in the economy is of great interest in the literature of economics, and is usually measured in monetary terms based on the data on capital expenditure. In spite of its wide use by economists, this measure of “capital stock” is of very limited use for sustainable management of Material stock because of its neglect of physical properties such as the mass and Material composition. This paper proposes a new method of measuring the stock of long-lived durables and infrastructure in terms of the mass of its Materials. This method is based on the WIO-MFA method [S. Nakamura et al. J . Ind . Ecol . 11 (2007) 50-63] and the capital formation matrix that is one of the supplementary tables of the input-Output table. The method is applied to the Japanese input-Output data with 400 sectors, with 9 types of metals (iron, ferroalloy, copper, zinc, lead, tin, aluminum, silver, and gold) and 8 types of plastics (thermo-setting resins, PE (low), PE (high), PS, PP, PVC, high-performance resins, and other resins) occurring as Materials. It was found that substantial variations exist among sectors while fixed capital formation in the year 2000 weighs 518 kg per million Japanese yen on average in metals and plastics.
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Identifying the Substance Flow of Metals Embedded in Japanese International Trade by Use of Waste Input-Output Material Flow Analysis (WIO-MFA) Model
Isij International, 2011Co-Authors: Kenichi Nakajima, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Keisuke Nansai, Shigemi Kagawa, Rokuta Inaba, Tetsuya NagasakaAbstract:This study proposes a method of combining a waste input–Output Material flow analysis (WIO-MFA) model with trade statistical data to identify the flows of substances embedded in trade commodities. We focused on the case of Japan as a typical processing and trading country, and we estimated each mass of iron and aluminum embedded in the imports and exports of 300 product items categorized in the WIO-MFA. We found that iron ore imported from Australia, Brazil, and India as a raw Material is processed and exported to South Korea, China, and other Asian countries as steel Materials and to the United States as steel Materials and automobiles. Primary aluminum imported from Russia, Australia, and Brazil as a raw Material is processed and exported to Asia as rolled Materials and to the United States as rolled Materials and automobiles.