2022/01/20 更新

写真a

ナカムラ シンイチロウ
中村 慎一郎
所属
政治経済学術院 政治経済学部
職名
教授

兼担

  • 政治経済学術院   大学院経済学研究科

  • 政治経済学術院   大学院政治学研究科

  • 理工学術院   大学院環境・エネルギー研究科

学内研究所等

  • 1989年
    -
     

    現代政治経済研究所   兼任研究員

学歴

  •  
    -
    1983年

    ボン大学   経済学研究科   理論経済学  

  •  
    -
    1974年

    慶應義塾大学   経済学部  

学位

  • ボン大学 (ドイツ)   Dr. rer. pol.

  • University of Bonn (Germany)   Dr. rer. pol.

経歴

  • 2005年
    -
    2012年

    名古屋大学エコトピア科学研究所客員教授

  • 1988年
    -
    1990年

    トロント大学訪問準教授

  • 1979年
    -
    1985年

    ボン大学 研究員

所属学協会

  •  
     
     

    日本LCA学会

  •  
     
     

    日本鉄鋼協会

  •  
     
     

    国際産業エコロジー学会

 

研究分野

  • 経済統計

  • 環境影響評価

研究キーワード

  • LCA、ライフサイクルアセスメント,マテリアルフロー解析、、産業エコロジー、計量経済学、産業連関分析

論文

  • Tracing the Consumption Origins of Wastewater and Sludge for a Chinese City Based on Waste Input-Output Analysis

    Lishan Xiao, Chen Lin, Shinichiro Nakamura

    Environmental Science and Technology   54 ( 19 ) 12560 - 12567  2020年10月  [査読有り]

    担当区分:最終著者

     概要を見る

    Water scarcity and pollution are grand challenges to sustainability. We developed a high-resolution wastewater input-output model for a Chinese city, Xiamen, incorporating detailed information on the treatment and quality of wastewater and sludge. We estimated consumption-based wastewater and sludge footprints of products (W2F and SF, respectively). Significant differences were found between the amounts of direct discharge (scope 1) and W2F (scopes 1-3), indicating the need to consider W2F in making plans for future wastewater management strategies. Reflecting its high organic content, food-related consumption was found to be a significant contributor to sludge generation. Scenario analyses were conducted to assess the effects of a shift from the traditional Chinese diet to the European diet and the anticipated industrial growth. Attempts were also made to establish links between the direct wastewater discharge of households and the final consumption of food items through human excretion, or the postconsumption footprints. It was found that the postconsumption W2F outweighed the preconsumption W2F for five out of nine food items, while the postconsumption SF outweighed the preconsumption SF in all cases except one. This research provides a scientific basis to identify the economy-wide fate of wastewater and sludge and to frame a policy for sustainable wastewater and sludge management.

    DOI PubMed

  • Tracking the Product Origins of Waste for Treatment Using the WIO Data Developed by the Japanese Ministry of the Environment

    Shinichiro Nakamura

    Environmental Science and Technology    2020年  [査読有り]

    担当区分:筆頭著者

     概要を見る

    Almost any production and consumption activity generates waste directly or indirectly over its supply chain. This paper is concerned with identifying the product origins of waste or waste footprint of products. It uses the waste input-output (WIO) data recently developed and published by the Japanese Ministry of the Environment (MOE), which is, to date, one of the publicly available WIO data with the highest resolution in products and waste. Results show that footprint calculation can identify factors behind the waste flows that otherwise would not be recognizable. The amount of waste for landfill is smaller than that for incineration only because around 80% of potential waste for landfill, mostly construction waste, is absorbed by recycling, attributed to public capital formation. Without this massive demand for recycling, the amount of waste sent to landfill would have been five to six times larger than the actual one, exceeding incineration. Footprint analysis of plastic waste reveals that targeting only postconsumer plastics waste is misleading, because most plastics waste has its origins in production. Service industries are found to be a major contributor to waste incineration and landfill in terms of footprint, whereas their contribution is minor in direct discharge.

    DOI PubMed

  • Approaches to solving China’s marine plastic pollution and CO<inf>2</inf> emission problems

    Chen Lin, Shinichiro Nakamura

    Economic Systems Research   31 ( 2 ) 143 - 157  2019年04月  [査読有り]

    担当区分:最終著者

     概要を見る

    Global contamination of the oceans by waste plastics is of increasing concern. Besides being the largest emitter of CO in the world, China is suspected of being the largest contributor to marine plastic waste pollution. Responsible for the latter is the still inadequate management of waste in China, a significant improvement of which is necessary for addressing the issue of marine plastic pollution. Since plastics are hydrocarbons, submitting them to appropriate waste treatment/recycling technologies could contribute to mitigating the emission of CO , indicating the possibility of addressing the two environmental issues simultaneously. Based on the combined use of waste input–output and linear programming, we investigated options for mitigating CO emissions under consideration of alternative waste treatment/recycling processes applied to waste plastics of China. It was found that of the nine processes considered, four could result in a net reduction in the emission: a win-win situation. 2 2 2

    DOI

  • Toward an integrated model of the circular economy: Dynamic waste input–output

    Shinichiro Nakamura, Yasushi Kondo

    Resources, Conservation and Recycling   139   326 - 332  2018年12月  [査読有り]

     概要を見る

    © 2018 The Author(s) Since its development at the end of the previous century, the waste input–output (WIO) model has been extended to wide areas of industrial ecology including material flow analysis (MFA), life-cycle costing (LCC), regional analysis, and linear programming (LP)-based technology selection. To our knowledge, the dynamics of waste generation and recycling is an area of possible conceptual extension that remains least explored. Building upon our recent work on dynamic MFA, in this work, we develop a dynamic WIO (dWIO) model that fully considers the issue of quality in recycling that involves mixing, dissipation, and contamination.

    DOI

  • Optimal Recycling of Steel Scrap and Alloying Elements: Input-Output based Linear Programming Method with Its Application to End-of-Life Vehicles in Japan

    Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Yasushi Kondo, Shinichiro Nakamura, Yasuhiro Fukushima, Tetsuya Nagasaka

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   51 ( 22 ) 13086 - 13094  2017年11月  [査読有り]

     概要を見る

    Importance of end-of-life vehicles (ELVs) as an urban mine is expected to grow, as more people in developing countries are experiencing increased standards of living, while the automobiles are increasingly made using high-quality materials to meet stricter environmental and safety requirements. While most materials in ELVs, particularly steel, have been recycled at high rates, quality issues have not been adequately addressed due to the complex use of automobile materials, leading to considerable losses of valuable alloying elements. This study highlights the maximal potential of quality-oriented recycling of ELV steel, by exploring the utilization methods of scrap, sorted by parts, to produce electric-arc-furnace-based crude alloy steel with minimal losses of alloying elements. Using linear programming on the case of Japanese economy in 2005, we found that adoption of parts-based scrap sorting could result in the recovery of around 94-98% of the alloying elements occurring in parts scrap (manganese, chromium, nickel, and molybdenum), which may replace 10% of the virgin sources in electric arc furnace-based crude alloy steel production.

    DOI

  • Quantifying Recycling and Losses of Cr and Ni in Steel Throughout Multiple Life Cycles Using MaTrace-Alloy

    Shinichiro Nakamura, Yasushi Kondo, Kenichi Nakajima, Hajime Ohno, Stefan Pauliuk

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   51 ( 17 ) 9469 - 9476  2017年09月  [査読有り]

     概要を見る

    Alloying metals are indispensable ingredients of high quality alloy steel such as austenitic stainless steel, the cyclical use of which is vital for sustainable resource management. Under the current practice of recycling, however, different metals are likely to be mixed in an uncontrolled manner, resulting in function losses and dissipation of metals with distinctive functions, and in the contamination of recycled Steels. The latter could result in dilution loss, if metal scrap needed dilution with virgin iron to reduce the contamination below critical levels. Management of these losses resulting from mixing in repeated recycling of metals requires tracking of metals over multiple life cycles of products with compositional details. A new model (MaTrace-alloy) was developed that tracks the fate of metals embodied in each of products over multiple life cycles of products, involving accumulation, discard, and recycling, with compositional details at the level of both alloys and products. The model was implemented for the flow of Cr and Ni in the Japanese steel cycle involving 27 steel species and 115 final products. It was found that, under a high level of scrap sorting, greater than 70% of the initial functionality of Cr and Ni could be retained over a period of 100 years, whereas under a poor level of sorting, it could plunge to less than 30%, demonstrating the relevance of waste management technology in circular economy policies.

    DOI

  • Regional distribution and losses of end-of-life steel throughout multiple product life cycles Insights from the global multiregional MaTrace model

    Stefan Pauliuk, Yasushi Kondo, Shinichiro Nakamura, Kenichi Nakajima

    RESOURCES CONSERVATION AND RECYCLING   116   84 - 93  2017年01月  [査読有り]

     概要を見る

    Substantial amounts of post-consumer scrap are exported to other regions or lost during recovery and remelting, and both export and losses pose a constraint to desires for having regionally closed material cycles. To quantify the challenges and trade-offs associated with closed-loop metal recycling, we looked at the material cycles from the perspective of a single material unit and trace a unit of material through several product life cycles. Focusing on steel, we used current process parameters, loss rates, and trade patterns of the steel cycle to study how steel that was originally contained in high quality applications such as machinery or vehicles with stringent purity requirements gets subsequently distributed across different regions and product groups such as building and construction with less stringent purity requirements. We applied MaTrace Global, a supply-driven multiregional model of steel flows coupled to a dynamic stock model of steel use. We found that, depending on region and product group, up to 95% of the steel consumed today will leave the use phase of that region until 2100, and that up to 50% can get lost in obsolete stocks, landfills, or slag piles until 2100. The high losses resulting from business-as-usual scrap recovery and recycling can be reduced, both by diverting postconsumer scrap into long-lived applications such as buildings and by improving the recovery rates in the waste management and remelting industries. Because the lifetimes of high-quality (cold-rolled) steel applications are shorter and remelting occurs more often than for buildings and infrastructure, we found and quantified a tradeoff between low losses and high-quality applications in the steel cycle. Furthermore, we found that with current trade patterns, reduced overall losses will lead to higher fractions of secondary steel being exported to other regions. Current loss rates, product lifetimes, and trade patterns impede the closure of the steel cycle. (C) 2016 Elsevier B.V. All rights reserved.

    DOI

  • Thermodynamic Considerations of Contamination by Alloying Elements of Remelted End-of-Life Nickel- and Cobalt-Based Superalloys

    Xin Lu, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

    METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE   47 ( 3 ) 1785 - 1795  2016年06月  [査読有り]

     概要を見る

    Cobalt and nickel are high-value commodity metals and are mostly used in the form of highly alloyed materials. The alloying elements used may cause contamination problems during recycling. To ensure maximum resource efficiency, an understanding of the removability of these alloying elements and the controllability of some of the primary alloying elements is essential with respect to the recycling of end-of-life (EoL) nickel- and cobalt-based superalloys by remelting. In this study, the distribution behaviors of approximately 30 elements that are usually present in EoL nickel- and cobalt-based superalloys in the solvent metal (nickel, cobalt, or nickel-cobalt alloy), oxide slag, and gas phases during the remelting were quantitatively evaluated using a thermodynamic approach. The results showed that most of the alloying elements can be removed either in the slag phase or into the gas phase. However, the removal of copper, tin, arsenic, and antimony by remelting is difficult, and they remain as tramp elements during the recycling. On the other hand, the distribution tendencies of iron, molybdenum, and tungsten can be controlled by changing the remelting conditions. To increase the resource efficiency of recycling, preventing contamination by the tramp elements and identifying the alloying compositions of EoL superalloys are significantly essential, which will require the development of efficient prior alloy-sorting systems and advanced separation technologies. (C) The Minerals, Metals & Materials Society and ASM International 2016

    DOI

  • Toward the efficient recycling of alloying elements from end of life vehicle steel scrap (vol 100, pg 11, 2015)

    Ohno Hajime, Matsubae Kazuyo, Nakajima Kenichi, Kondo Yasushi, Nakamura Shinichiro, Nagasaka Tetsuya

    RESOURCES CONSERVATION AND RECYCLING   109   202  2016年05月  [査読有り]

    DOI

  • Assessment of soil remediation technologies by comparing health risk reduction and potential impacts using unified index, disability-adjusted life years

    Iwao Sakaguchi, Yasushi Inoue, Shinichiro Nakamura, Yoshihiro Kojima, Ryo Sasai, Kayo Sawada, Kenji Suzuki, Chisato Takenaka, Arata Katayama

    CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY   17 ( 6 ) 1663 - 1670  2015年08月  [査読有り]

     概要を見る

    The assessment methodology of soil remediation technologies including citizen's opinions about environmental policy was developed to enable direct comparison between the resident health risk reduction by carrying out remediation (decreased primary risk) and the potential impacts of chemicals emitted during the remediation on national health, social assets, and primary production (secondary risk). Both risks were quantified with an unified index, disability-adjusted life years (DALYs), by employing life cycle costing (LCC), economic input-output life cycle assessment (EIO-LCA), and life cycle impact assessment (LCIA) database. Four remediation technologies were considered: excavation-disposal, high temperature thermal desorption (HTTD), biopile, and landfarming. There was almost no difference in the decreased primary risk among the four technologies, apart from landfarming, which had the smallest decreased primary risk. The secondary risk of the biological technologies (biopile, landfarming) was smaller than that of the physical and chemical technologies (excavation-disposal, HTTD). The ratio of the decreased primary risk to the secondary risk was largest in case of landfarming, which indicated that landfarming was most effective. The sum of the residual primary risks and secondary risk was small in the biological technologies, indicating that the biological technologies had smaller environmental impacts. Indexing both of decreased primary risk and secondary risk with DALYs enables non-experts who prioritize resident's health to assess the soil remediation technologies and would facilitate the decision making in the selection of remediation technologies.

    DOI

  • Identification of the driving force of waste generation using a high-resolution waste input-output table

    Meng-i Liao, Pi-cheng Chen, Hwong-wen Ma, Shinichiro Nakamura

    JOURNAL OF CLEANER PRODUCTION   94   294 - 303  2015年05月  [査読有り]

     概要を見る

    Effective strategic planning for industrial waste management requires sound knowledge of the waste streams in an economy. Based on an input output analysis with an extended function to consider the entire life cycle of a product, waste input output (WIO) analysis plays an important role in describing the driving forces behind the generation of industrial waste. In this study, we compile a high-resolution WIO table for Taiwan that traces the flow of waste streams covering almost all types of waste emitted from industries into corresponding wake treatments and that identifies the driving force of waste in the economic system. In addition, we generate a detailed breakdown of the final demand categories into sub-categories to clarify consumption patterns or lifestyles that produce specific waste streams. The results show that export is the main driving force generating industrial waste. This dominance is obvious for "waste acidic etchants" and "copper and copper compounds", of which the electronic parts and components sector is the largest generator. In addition, this study reveals the industries that create the substantial demand for incinerators and landfills. This article illuminates the diagnostic features of the high-resolution WIO table and provides useful insights for linking the WIO and supply chain analysis approaching sustainable consumption and production. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

  • Forecasting Replacement Demand of Durable Goods and the Induced Secondary Material Flows A Case Study of Automobiles

    Shigemi Kagawa, Shinichiro Nakamura, Yasushi Kondo, Kazuyo Matsubae, Tetsuya Nagasaka

    JOURNAL OF INDUSTRIAL ECOLOGY   19 ( 1 ) 10 - 19  2015年02月  [査読有り]

     概要を見る

    The aim of this article is to propose a method for forecasting future secondary material flows by combining a product lifetime distribution analysis with a waste input-output analysis and present a simple case study of automobiles. The case study demonstrates that the proposed method enables us to estimate replacement demand of new vehicles, number of end-of-life (EOL) vehicles arising from the aging of vehicles, volume of shredder scraps recovered from EOL vehicles, and volume of shredder scraps required to meet final consumption in the future.

    DOI

  • Thermodynamic Analysis for the Refining Ability of Salt Flux for Aluminum Recycling

    Takehito Hiraki, Takahiro Miki, Kenichi Nakajima, Kazuyo Matsubae, Shinichiro Nakamura, Tetsuya Nagasaka

    MATERIALS   7 ( 8 ) 5543 - 5553  2014年08月  [査読有り]

     概要を見る

    The removability of impurities during the aluminum remelting process by oxidation was previously investigated by our research group. In the present work, alternative impurity removal with chlorination has been evaluated by thermodynamic analysis. For 43 different elements, equilibrium distribution ratios among metal, chloride flux and oxide slag phases in the aluminum remelting process were calculated by assuming the binary systems of aluminum and an impurity element. It was found that the removability of impurities isn't significantly affected by process parameters such as chloride partial pressure, temperature and flux composition. It was shown that Ho, Dy, Li, La, Mg, Gd, Ce, Yb, Ca and Sr can be potentially eliminated into flux by chlorination from the remelted aluminum. Chlorination and oxidation are not effective to remove other impurities from the melting aluminum, due to the limited parameters which can be controlled during the remelting process. It follows that a proper management of aluminum scrap such as sorting based on the composition of the products is important for sustainable aluminum recycling.

    DOI

  • MaTrace: Tracing the Fate of Materials over Time and Across Products in Open-Loop Recycling

    Shinichiro Nakamura, Yasushi Kondo, Shigemi Kagawa, Kazuyo Matsubae, Kenichi Nakajima, Tetsuya Nagasaka

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   48 ( 13 ) 7207 - 7214  2014年07月  [査読有り]

     概要を見る

    Even for metals, open-loop recycling is more common than closed-loop recycling due, among other factors, to the degradation of quality in the end-of-life (EoL) phase. Open-loop recycling is subject to loss of functionality of original materials, dissipation in forms that are difficult to recover, and recovered metals might need dilution with primary metals to meet quality requirements. Sustainable management of metal resources calls for the minimization of these losses. Imperative to this is quantitative tracking of the fate of materials across different stages, products, and losses. A new input-output analysis (IO) based model of dynamic material flow analysis (MFA) is presented that can trace the fate of materials over time and across products in open-loop recycling taking explicit consideration of losses and the quality of scrap into account. Application to car steel recovered from EoL vehicles (ELV) showed that after 50 years around 80% of the steel is used in products, mostly buildings and civil engineering (infrastructure), with the rest mostly resided in unrecovered obsolete infrastructure and refinery losses. Sensitivity analysis was conducted to evaluate the effects of changes in product lifespan, and the quality of scrap.

    DOI

  • Unintentional Flow of Alloying Elements in Steel during Recycling of End-of-Life Vehicles

    Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

    JOURNAL OF INDUSTRIAL ECOLOGY   18 ( 2 ) 242 - 253  2014年04月  [査読有り]

     概要を見る

    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.

    DOI

  • 自動車リサイクルにおける鉄鋼合金のフロー解析

    松八重一代, 大野肇, 中島謙一, 中村愼一郎, 長坂徹也

    ふぇらむ   18 ( 12 ) 743 - 747  2013年12月

  • 鉄と鋼と産業連関

    中村愼一郎

    ふぇらむ   18 ( 7 ) 398 - 402  2013年07月

  • Simultaneous material flow analysis of nickel, chromium, and molybdenum used in alloy steel by means of input-output analysis

    Kenichi Nakajima, Hajime Ohno, Yasushi Kondo, Kazuyo Matsubae, Osamu Takeda, Takahiro Miki, Shinichiro Nakamura, Tetsuya Nagasaka

    Environmental Science and Technology   47 ( 9 ) 4653 - 4660  2013年05月  [査読有り]

     概要を見る

    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. Improvement in EoL sorting technologies and implementation of designs for recycling/disassembly at the manufacturing phase are needed. Possible solutions include development of sorting processes for steel scrap and introduction of easier methods for identifying the composition of secondary resources. Recovery of steel scrap with a high alloy content will reduce primary inputs of alloying elements and contribute to more efficient resource use. © 2013 American Chemical Society.

    DOI PubMed

  • Quality- and Dilution Losses in the Recycling of Ferrous Materials from End-of-Life Passenger Cars: Input-Output Analysis under Explicit Consideration of Scrap Quality

    Shinichiro Nakamura, Yasushi Kondo, Kazuyo Matsubae, Kenichi Nakajima, Tomohiro Tasaki, Tetsuya Nagasaka

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   46 ( 17 ) 9266 - 9273  2012年09月  [査読有り]

     概要を見る

    Metals can in theory be infinitely recycled in a closed-loop without any degradation in quality. In reality, however, open-loop recycling is more typical for metal scrap recovered from end-of-life (EoL) products because mixing of different metal species results in scrap quality that no longer matches the originals. Further losses occur when meeting the quality requirement of the target product requires dilution of the secondary material by adding high purity materials. Standard LCA usually does not address these losses. This paper presents a novel approach to quantifying quality- and dilution losses, by means of hybrid input-output analysis. We focus on the losses associated with the recycling of ferrous materials from end-of-life vehicle (ELV) due to the mixing of copper, a typical contaminant in steel recycling. Given the quality of scrap in terms of copper density, the model determines the ratio by which scrap needs to be diluted in an electric arc furnace (EAF), and the amount of demand for EAF steel including those quantities needed for dilution. Application to a high-resolution Japanese IO table supplemented with data on ferrous materials including different grades of scrap indicates that a nationwide avoidance of these losses could result in a significant reduction of CO2 emissions.

    DOI

  • Thermodynamic analysis of separation of alloying elements in recycling of end-of-life titanium products

    X. Lu, T. Hiraki, K. Nakajima, O. Takeda, K. Matsuabe, H. -M. Zhu, S. Nakamura, T. Nagasaka

    SEPARATION AND PURIFICATION TECHNOLOGY   89   135 - 141  2012年03月  [査読有り]

     概要を見る

    The separation and control of undesired elements are key to recycling scrap or end-of-life (EoL) metal products, as the quality of regenerated metals is often impaired by contamination from the alloying elements in the scrap. However, little is known of their removability or controllability because they are normally absent in the production of primary metal from natural ore. Here, the distribution ratios of 31 kinds of alloying element among the metal, slag, and gas phases in the re-melting of EoL titanium products were quantitatively discussed. Our results clarified that the typical titanium alloying elements - Al, Fe, and V - are essentially uncontrollable in re-melted titanium by oxidation or evaporation. This suggests that the mixing of commercially pure titanium (CP-Ti) and other titanium alloys should be avoided. Hence, the development of new technologies to separate alloying elements from titanium scraps for sustainable titanium recycling is highly anticipated. (C) 2012 Elsevier B.V. All rights reserved.

    DOI

  • The anatomy of capital stock: input-output material flow analysis (MFA) of the material composition of physical stocks and its evolution over time

    Y. Kondo, K. Nakajima, K. Matsubae, S. Nakamura

    REVUE DE METALLURGIE-CAHIERS D INFORMATIONS TECHNIQUES   109 ( 5 ) 293 - 298  2012年  [査読有り]

     概要を見る

    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.

    DOI

  • Hybrid Input-Output Analysis as a Tool for Communication Among Scientists of Different Disciplines Experiences With Metallurgy and Materials Science

    Shinichiro Nakamura

    JOURNAL OF INDUSTRIAL ECOLOGY   15 ( 5 ) 661 - 663  2011年10月  [査読有り]

    DOI

  • Thermodynamic criteria for the removal of impurities from end-of-life magnesium alloys by evaporation and flux treatment

    Takehito Hiraki, Osamu Takeda, Kenichi Nakajima, Kazuyo Matsubae, Shinichiro Nakamura, Tetsuya Nagasaka

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   12 ( 3 )  2011年06月  [査読有り]

     概要を見る

    In this paper, the possibility of removing impurities during magnesium recycling with pyrometallurgical techniques has been evaluated by using a thermodynamic analysis. For 25 different elements that are likely to be contained in industrial magnesium alloys, the equilibrium distribution ratios between the metal, slag and gas phases in the magnesium remelting process were calculated assuming binary systems of magnesium and an impurity element. It was found that calcium, gadolinium, lithium, ytterbium and yttrium can be removed from the remelted end-of-life (EoL) magnesium products by oxidization. Calcium, cerium, gadolinium, lanthanum, lithium, plutonium, sodium, strontium and yttrium can be removed by chlorination with a salt flux. However, the other elements contained in magnesium alloy scrap are scarcely removed and this may contribute toward future contamination problems. The third technological option for the recycling of EoL magnesium products is magnesium recovery by a distillation process. Based on thermodynamic considerations, it is predicted that high-purity magnesium can be recovered through distillation because of its high vapor pressure, yet there is a limit on recoverability that depends on the equilibrium vapor pressure of the alloying elements and the large energy consumption. Therefore, the sustainable recycling of EoL magnesium products should be an important consideration in the design of advanced magnesium alloys or the development of new refining processes.

    DOI

  • UPIOM: A New Tool of MFA and Its Application to the Flow of Iron and Steel Associated with Car Production

    Shinichiro Nakamura, Yasushi Kondo, Kazuyo Matsubae, Kenichi Nakajima, Tetsuya Nagasaka

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   45 ( 3 ) 1114 - 1120  2011年02月  [査読有り]

     概要を見る

    Identification of the flow of materials and substances associated with a product system provides useful information for Life Cycle Analysis (LCA), and contributes to extending the scope of complementarity between LCA and Materials Flow Analysis/Substances Flow Analysis (MFA/SFA), the two major tools of industrial ecology. This paper proposes a new methodology based on input-output analysis for identifying the physical input-output flow of individual materials that is associated with the production of a unit of given product, the unit physical input-output by materials (UPIOM). While the Sankey diagram has been a standard tool for the visualization of MFA/SFA, with an increase in the complexity of the flows under consideration, which will be the case when economy-wide intersectoral flows of materials are involved, the Sankey diagram may become too complex for effective visualization. An alternative way to visually represent material flows is proposed which makes use of triangulation of the flow matrix based on degrees of fabrication. The proposed methodology is applied to the flow of pig iron and iron and steel scrap that are associated with the production of a passenger car in Japan. Its usefulness to identify a specific MFA pattern from the original 10 table is demonstrated.

    DOI

  • Role of Motor Vehicle Lifetime Extension in Climate Change Policy

    Shigemi Kagawa, Keisuke Nansai, Yasushi Kondo, Klaus Hubacek, Sangwon Suh, Jan Minx, Yuki Kudoh, Tomohiro Tasaki, Shinichiro Nakamura

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   45 ( 4 ) 1184 - 1191  2011年02月  [査読有り]

     概要を見る

    Vehicle replacement schemes such as the "cash for clunkers" program in the U.S. and the "scrappage scheme" in the UK have featured prominently in the economic stimulation packages initiated by many governments to cope with the global economic crisis. While these schemes were designed as economic instruments to support the vehicle production industry, governments have also claimed that these programs have environmental benefits such as reducing CO(2) emissions by bringing more fuel-efficient vehicles onto the roads. However, little evidence is available to support this claim as current energy and environmental accounting models are inadequate for comprehensively capturing the economic and environmental trade-offs associated with change&apos;s in product life and product use. We therefore developed a new dynamic model to quantify the carbon emissions due to changes in product life and consumer behavior related to product use. Based on a case study of Japanese vehicle use during the 1990-2000 period, we found that extending, not shortening, the lifetime of a vehicle helps to reduce life-cycle CO(2) emissions throughout the supply chain. Empirical results also revealed that even if the fuel economy of less fuel-efficient ordinary passenger vehicles were improved to levels comparable with those of the best available technology, i.e. hybrid passenger cars currently being produced in Japan, total CO(2) emissions would decrease by only 0.2%. On the other hand, we also find that extending the lifetime of a vehicle contributed to a moderate increase in emissions of health-relevant air pollutants (NO(x), HC, and CO) during the use phase. From the results, this study concludes that the effects of global warming and air pollution can be somewhat moderated and that these problems can be addressed through specific policy instruments directed at increasing the market for hybrid cars as well as extending lifetime of automobiles, which is contrary to the current wisdom.

    DOI

  • 耐久財の動的廃棄物産業連関分析:乗用車利用の場合

    加河 茂美, 中村 愼一郎, 近藤 康之, 松八重 一代, 長坂 徹也

    日本LCA学会研究発表会講演要旨集   2011 ( 0 ) 54 - 54  2011年

     概要を見る

    Replacement demand of durable goods such as automobile is not only an important driving force of economic growth but also a key factor in emissions reduction. Considering the future replacement demand largely depend on engineering scrappage reflecting physical wear and tear which increases with products age and/or use (Greenspan and Cohen, 1999), this study proposed a novel method to forecast the replacement demand of durable goods and the life cycle emissions by incorporating product lifetime distributions reflecting the engineering scrappage into the waste input-output analysis (Nakamura and Kondo, 2009).

    CiNii

  • WIO-MFAによる鉄鋼製品の国際貿易に随伴するCr, Ni, Moフロー解析

    大野 肇, 松八重 一代, 中島 謙一, 中村 愼一郎, 長坂 徹也

    日本LCA学会研究発表会講演要旨集   2011 ( 0 ) 121 - 121  2011年

     概要を見る

    我が国は鉄鋼合金元素の一次資源のほぼ全量を海外から輸入している。これらの多くは特殊鋼鋼材に含まれ、最終的に様々な製品に組み込まれ、国内で消費及び蓄積されるか、再び海外へと輸出される。 本研究では、廃棄物産業連関分析に基づくマテリアルフロー分析手法(WIO-MFA)と、貿易統計等から得られる貿易量情報を組み合わせることにより、合金元素の海外を含めた最終需要先を明らかにし、資源有効利用の可能性を検討する。

    CiNii

  • Impact of the Recovery of Secondary Ferrous Materials from Alternative ELV Treatment Methods on CO2 Emission: A Waste Input Output Analysis

    Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

    ISIJ INTERNATIONAL   51 ( 1 ) 151 - 157  2011年  [査読有り]

     概要を見る

    The demand for iron and steel materials has been increasing mainly because of the rapid economic growth of the BRIC countries. The annual worldwide production of crude steel is approximately 2 billion tons. There has been a corresponding increase in the production of crude steel in Japan. As a result, the significance of Japan as a source of iron and steel scraps has also increased.(1))
    Scrap recycling, however, is subject to some problems, such as unstable supply conditions and contamination by impurities.(2)) A significant part of these problems can be attributed to the increasing use of electric devices, such as circuit boards, motors, and wiring harnesses, in high-tech products. These electric devices/equipments contain many kinds of metals, such as copper, lead, and zinc, which can become a source of contamination of steel scrap recovered from end-of-life vehicles (ELVs) or home appliances.
    Here the contamination of tramp elements was analyzed using a Waste Input Output model, considering the following points: (1) the amount of ferrous scrap usage in iron and steel production process, (2) copper elimination from ELV scraps, and (3) contamination of copper in iron and steel products.
    The results of scenario analysis indicated that copper contamination in crude steel production associated with the use of scrap from ELVs could be reduced by 2 % by the use of a more recycle-oriented ELV treatment. The effects of copper elimination on CO2 emission were more significant for ordinary steel production than special steel production.

  • Identifying the Substance Flow of Metals Embedded in Japanese International Trade by Use of Waste Input-Output Material Flow Analysis (WIO-MFA) Model

    Kenichi Nakajima, Keisuke Nansai, Kazuyo Matsubae, Yasushi Kondo, Shigemi Kagawa, Rokuta Inaba, Shinichiro Nakamura, Tetsuya Nagasaka

    ISIJ INTERNATIONAL   51 ( 11 ) 1934 - 1939  2011年  [査読有り]

     概要を見る

    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.

    DOI

  • Thermodynamic Analysis of Contamination by Alloying Elements in Aluminum Recycling

    Kenichi Nakajima, Osamu Takeda, Takahiro Miki, Kazuyo Matsubae, Shinichiro Nakamura, Tetsuya Nagasaka

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   44 ( 14 ) 5594 - 5600  2010年07月  [査読有り]

     概要を見る

    In previous studies on the physical chemistry of pyrometallurgical processing of aluminum scrap, only a limited number of thermodynamic parameters, such as the Gibbs free energy change of impurity reactions and the variation of activity of an impurity in molten aluminum, were taken into account In contrast, in this study we thermodynamically evaluated the quantitative removal limit of impurities during the remelting of aluminum scrap; all relevant parameters, such as the total pressure, the activity coefficient of the target impurity, the temperature, the oxygen partial pressure, and the activity coefficient of oxidation product, were considered. For 45 elements that usually occur in aluminum products, the distribution ratios among the metal, slag, and gas phases in the aluminum remelting process were obtained. Our results show that, except for elements such as Mg and Zn, most of the impurities occurred as troublesome tramp elements that are difficult to remove, and our results also indicate that the extent to which the process parameters such as oxygen partial pressure, temperature, and flux composition can be changed in aluminum production is quite limited compared to that for iron and copper production, owing to aluminum&apos;s relatively low melting point and strong affinity for oxygen. Therefore, the control of impurities in the disassembly process and the quality of scrap play important roles in suppressing contamination in aluminum recycling.

    DOI

  • Hybrid LCA of a Design for Disassembly Technology: Active Disassembling Fasteners of Hydrogen Storage Alloys for Home Appliances

    Shinichiro Nakamura, Eiji Yamasue

    ENVIRONMENTAL SCIENCE & TECHNOLOGY   44 ( 12 ) 4402 - 4408  2010年06月  [査読有り]

     概要を見る

    In the current recycling system of end-of-life (EoL) appliances, which is based on shredding, alloying elements tend to end up in the scrap of base metals. The uncontrolled mixing of alloying elements contaminates secondary metals and calls for dilution with primary metals. Active disassembling fastener (ADF) is a design for disassembly (DfD) technology that is expected to solve this problem by significantly reducing the extent of mixing. This paper deals with a life cycle assessment (LCA) based on the waste input-output (WIO) model of an ADF developed using hydrogen storage alloys. Special attention is paid to the issue of dilution of mixed iron scrap using pig iron in an electric arc furnace (EAF). The results for Japanese electrical and electronic appliances indicate superiority of the recycling system based on the ADF over the current system in terms of reduced emissions of CO2. The superiority of ADF was found to increase with an increase in the requirement for dilution of scrap.

    DOI

  • WIO-MFAモデルを利用した金属の国際マテリアルフロー分析

    中島 謙一, 南斉 規介, 松八重 一代, 中村 愼一郎, 長坂 徹也

    日本LCA学会研究発表会講演要旨集   2010 ( 0 ) 83 - 83  2010年

     概要を見る

    近年、リサイクル資源を含めた資源の需給構造、および国際的な物質バランスを定量化するための手法として、マテリアルフロー分析(MFA)が有益とされている。本稿では、WIO-MFAモデルを応用した国際マテリアルフロー分析に関する研究事例として、鉄やアルミニウムを対象元素として取り上げて日本を中心とした国際マテリアルフローを明らかにする。

    CiNii

  • 廃棄物産業連関分析を応用したトップダウン型MFAモデルの開発

    中島謙一, 中村愼一郎, 松八重一代, 近藤康之, 長坂徹也

    廃棄物資源循環学会誌   20 ( 5 ) 206 - 211  2009年

  • 社会基盤素材を介したサブスタンスフロー

    松八重一代, 中島謙一, 中村愼一郎, 長坂徹也

    廃棄物資源循環学会誌   20 ( 5 ) 227 - 236  2009年

  • WIO-MFAおよびSFA分析を通じた我が国の鉄資源循環とマンガンフロー分析

    横山一代, 中島謙一, 小野恭平, 中村愼一郎, 長坂徹也

    鋳造工学   80 ( 6 )  2008年06月  [査読有り]  [招待有り]

    DOI

  • A hybrid input-output approach to metal production and its application to the introduction of lead-free solders

    Shinichiro Nakamura, Shinsuke Murakami, Kenichi Nakajima, Tetsuya Nagasaka

    Environmental Science &amp; Technology   42 ( 10 ) 3843 - 3848  2008年

  • Five years in the area of input-output and hybrid LCA

    Sangwon Suh, Shinichiro Nakamura

    INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT   12 ( 6 ) 351 - 352  2007年09月  [査読有り]

    DOI

  • Measuring spatial repercussion effects of regional waste management

    Shigemi Kagawa, Shinichiro Nakamura, Hajime Inamura, Masato Yamada

    RESOURCES CONSERVATION AND RECYCLING   51 ( 1 ) 141 - 174  2007年07月  [査読有り]

     概要を見る

    The present paper proposes an analytical framework for measuring the spatial pollution repercussion effects of regional waste management. The empirical analysis using the 1995 nine-region waste input-output table reveals that as the regional population size become larger, the intraregional waste treatment level directly and indirectly induced by a person's consumption behaviour tends to be large due to economies of scale. In contrast, we especially find that the indirect household contributions per capita of the Chugoku and Shikoku region were, conversely, about 1.4 times larger than that of the Kanto region, because of the differences in the regional commodity consumption patterns. In comparing the actual economic system in 1995 with the hypothetical complete intraregional waste treatment system, we also find that the latter system increased total waste landfill by 18,103 tonnes, which amounts to 0.03% of the total waste landfill, revealing the location advantage of intermediate inputs for waste treatment activities and regional technological differences. (C) 2006 Elsevier B.V. All rights reserved.

    DOI

  • The Waste Input-Output Approach to Material Flow Analysis: Concepts and Application to Base Metals

    Shinichiro Nakamura, Kenichi Nakajima, Yasushi Kondo, Tetsuya Nagasaka

    Journal of Industrial Ecology   11 ( 4 ) 50 - 63  2007年

  • Hybrid LCC of appliances with different energy efficiency

    Shinichiro Nakamura, Yasushi Kondo

    INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT   11 ( 5 ) 305 - 314  2006年09月  [査読有り]

     概要を見る

    Goal, Scope and Background. This paper is concerned with a life cycle assessment (LCA) and life cycle costing (LCQ by the use of the waste input-output (WIO) quantity- and price model of air conditioners with different energy efficiency at the use phase (high-end, lowend and average models) that were available in Japan as of winter 2002. The functional unit is an air conditioner of the 2.5kW type that is used for 10 years, and then subjected to an end-of-life (EoL) process that is consistent with the Japanese law on the recycling of appliances.
    Methods. This is the first simultaneous application of the WIO methodology to an LCA and LCC over the entire life-cycle of a product including the use phase, and represents a methodological extension (in the sense of considering the use phase) and integration (in the sense of a simultaneous application) of previous studies by us (Kondo and Nakamura, Int J LCA 2004, Nakamura and Kondo, Ecol Econ 2006). The main body of data is provided by the WIO table for the year 2000, an update of the previous table for 1995 that was used in the above WIO studies. Compared with the WIO table for 1995 that consisted of only about 80 industry sectors, the current one consists of about 400 industry sectors, and includes air conditioner as a separate sector. The data on the purchase price and efficiency of air conditioners indicate wide variations: the cheapest one (the lowend model) costs half of the most expensive one (the high-end model), but its efficiency is about half of the latter.
    Results and Discussion. When the cost in the use and EoL phases is included, the low-end model becomes the most expensive one, and the high-end model with the highest purchase cost the least expensive. This reversal of the relative cost levels is attributed to the difference in the efficiency in the use phase. A sensitivity analysis indicates that a reduction of the electricity price in the use phase by about 40% does not alter the significant superiority of the high-end model over the low-end model. In spite of the largest amount of input in the production phase, the high-end model performs the best in terms of both global warming potential (GWP) and landfill, while the low-end model performs the worst. The use phase generates the largest amount of waste for landfill across the three models, the largest component of which is flyash generated from coal firing power plants. A possible internalization of externality in the form of carbon tax was found to work in favor of the high-end model. The cost advantage of the high-end model, however, is sensitive to the rate of discounting of future costs: discounting at 15% diminishes its advantage over the low-end model.
    Recommendation and Perspective. The results indicate the effectiveness of the pricing based on the life cycle cost for achieving sustainability, that is, for promoting the shift of the demand away from appliances with low environmental performance to the one with higher environmental performance. Acceptance by society of pricing based on life cycle costing would require, among other things, an economywide standardization of the LCC concept (in a manner analogous to ISO-LCA) that can be used complementary to ISO-LCA.

    DOI

  • A waste input-output life-cycle cost analysis of the recycling of end-of-life electrical home appliances

    Shinichiro Nakamura, Yasushi Kondo

    ECOLOGICAL ECONOMICS   57 ( 3 ) 494 - 506  2006年05月  [査読有り]

     概要を見る

    However excellent a product may be environmentally, it would not come into wide use in the economy to realize its environmental load reducing potential unless it is also economically affordable. Life-cycle costing (LCC) is a tool to assess the cost of a product over its entire life cycle, and can be regarded as an economic counterpart of LCA. A combined use of LCA and LCC would be imperative for assessing the sustainability of a product or product systems in the economy. This paper presents a new methodology of LCC which gives the cost and price counterpart of the hybrid LCA tool (Waste Input-Output, WIO) that was developed by Nakamura and Kondo (2002) [Nakamura, S., Kondo, Y., 2002. Input-output analysis of waste management. Journal of Industrial Ecology 6 (1), 39-63.1]for LCA of waste management. Building upon the preceding LCA study by Kondo and Nakamura (2004) [Kondo, Y., Nakamura, S., 2004. Evaluating alternative life-cycle strategies for electrical appliances by the waste input-output model. International Journal of Life Cycle Assessment 9 (4), 236-246.], the applicability of the methodology is illustrated by a case study of electric appliances under alternative end-of-life scenarios: landfilling, intensive recycling that is consistent with the Japanese law on the recycling of appliances, and an advanced form of intensive recycling augmented by Design for Disassembly (DfD). Application of the proposed LCC methodology indicates that while the life-cycle cost is the highest under intensive recycling and the lowest under landfilling, the cost of recycling can be reduced by appropriate implementation of MD. The possible introduction of a carbon tax is also found to significantly reduce the cost disadvantage of recycling against landfilling. Given the high level of environmental load associated with landfilling and the possible introduction of carbon taxes, Design for Environment or EcoDesign emerges as a strategy of vital importance to achieve the sustainability of appliances. (c) 2005 Elsevier B.V. All rights reserved.

    DOI

  • 産業連関分析を用いた環境LCC分析

    中村愼一郎

    日本LCA学会誌   2 ( 1 ) 15 - 21  2006年02月

  • Waste input-output material flow analysis of metals in the Japanese economy

    S Nakamura, K Nakajima

    MATERIALS TRANSACTIONS   46 ( 12 ) 2550 - 2553  2005年12月  [査読有り]

     概要を見る

    This paper develops a theoretical model of material flow analysis (MFA) within the framework of the Waste Input-Output model (WIO) (Nakamura and Kondo). The model is developed based on two fundamental ingredients: yield ratios and the degree of fabrication. In manufacturing process, multiplication of physical inputs by the yield ratios gives the portion that enters physical outputs, with the rest being discarded as process waste without entering outputs. In input-output analysis, the degree of fabrication can be visualized as triangularity of the input coefficients matrix (goods of lower degree of fabrication can enter those of higher fabrication, but the reverse does not hold), which is known to emerge through an appropriate reordering of sectors. Application to the Japanese 10 data indicates that the model can provide accurate estimates of the weight as well as the composition of metals (Fe, Cu. Pb, Zn. and At) used in a passenger car. The model is also used to estimate the major final use categories (household consumption, public consumption, capital investment, inventory investment, and export) of metals.

  • Waste input-output linear programming model with its application to eco-efficiency analysis

    Yasushi Kondo, Shinichiro Nakamura

    Economic Systems Research   17 ( 4 ) 393 - 408  2005年12月

     概要を見る

    This paper is concerned with a decision analytic extension of the waste input-output model, based on the method of linear programming. The resulting model, which is named the waste input-output linear programming model, allows one to automatically obtain an 'optimal' waste management and recycling strategy from among a given set of alternative feasible strategies. The model can thus explore the extent to which a given measure of eco-efficiency can be maximized by an appropriate combination of existing (technological and resource) potentials. An application to Japanese data is also presented. © 2005 The International Input-Output Association.

    DOI

  • Waste Input-Output Material Flow Analysis of Metals

    Shinichiro Nakamura, Keninci Nakajima

    Advancement in Ecomaterials, 7th International Conference on Ecomaterials   2   586 - 590  2005年07月

  • LCAにおける産業連関分析の可能性と廃棄物産業連関分析

    中村愼一郎

    産業連関   13 ( 2 ) 4 - 15  2005年06月

  • 廃棄物LCAと産業連関分析

    中村愼一郎

    日本LCA学会誌   1 ( 1 ) 29 - 33  2005年04月

  • 廃棄物産業連関分析 (WIO) と廃棄物管理最適化

    近藤康之, 中村愼一郎

    電気学会論文誌 C 電子・情報・システム部門誌   124-C ( 10 ) 2187 - 2194  2004年

  • Evaluating alternative life-cycle strategies for electrical appliances by the waste input-output model

    Y Kondo, S Nakamura

    INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT   9 ( 4 ) 236 - 246  2004年  [査読有り]

     概要を見る

    Goal, Scope and Background. In 2001, a new law on the recycling of end-of-life electric home appliances (EL-EHA) was put into effect in Japan; it was the first legislation of its sort in the world, and deserves to be called the 'Japan model.' This article is concerned with the LCA of alternative life-cycle strategies for EL-EHA, which consist of recycling as prescribed by the law, 'ecodesign' strategies such as the implementation of design for disassembly (DfD) and the extension of product life (EPL), with and without ex-post functional upgradability, and the once-dominant treatment methods such as landfilling and simple shredding.
    Methods. We use the waste input-output (WIO) analysis, a new method of hybrid LCA that was developed by the authors [I]. The WIO extends the conventional input-output analysis to explicitly take into account the interdependence between the flow of goods and the flow of waste in the whole economy, and. hence provides an optimal platform for LCA involving waste treatment and recycling. Furthermore, the WIO enables us to evaluate not only environmental impacts, but also economic: impacts such as sectoral output and employment. Our analysis is based on the WIO table for 1995 and detailed process data. on recycling.
    Results and Discussion. Recycling was found to outperform the 'traditional' treatment method strategy with regard to the reduction of CO2 emission, landfill consumption, and the demand for abiotic resources. Thanks to efficient utilization of the existing retail network system, it was also found to be more efficient economically. Additional implementation of DfD and the associated increase in the quality of recovered materials (plastics) were found to augment the positive environmental impacts of recycling. The EPL without upgrading resulted in a significant reduction in the environmental impacts, but also in the level of employment. On the other hand, the EPL with upgrading was found to outperform the recycling strategy in terms of environmental impacts without having significant negative economic impacts.
    Conclusion and Recommendation. Recycling of EL-EHA, as prescribed by the Japanese law on the recycling of EL-EHA, was found to be effective in reducing CO, emission, depletion of abiotic resources, generation of waste, and landfill consumption, provided the rate of retrieval remains at a high level. Our results also indicate the possible effectiveness of ecodesign strategy toward the realization of a sustainable economy.

    DOI

  • Input-output analysis of waste management

    Shinichiro Nakamura, Yasushi Kondo

    Journal of Industrial Ecology   6 ( 1 ) 39 - 63  2002年12月

     概要を見る

    A new scheme of hybrid life-cycle assessment (LCA) termed the waste input-output (WIO) model is presented that explicitly takes into account the interdependence between the flow of goods and waste. The WIO model has two distinguishing features. First, it expands the Leontief environmental input-output (EIO) model with respect to waste flows. It turns out that the EIO model is a special case of the WIO model in which there is a strict one-to-one correspondence between waste types and treatment methods. By relaxing this condition, the WIO model provides a general framework for LCA of waste management. Second, the WIO model takes into account the "dynamics of waste treatment," which refers to the fact that the input-output relationships of waste treatment are significantly affected by the level and composition of waste feedstock, by incorporating an engineering process model of waste treatment. Because waste treatment is expected to accept whatever waste is generated by industry and households, a proper consideration of this feature is vital for LCA of waste management. We estimated a WIO table for Japan and applied it to evaluating effects of alternative waste management policies with regard to regional concentration of incineration and the sorting of waste with regard to flammability. We found that concentrating treatment in a small number of large incinerators combined with an increased degree of sorting could decrease both landfill consumption and the emission of carbon dioxide.

    DOI

  • Recycling, landfill consumption, and CO2 emission: analysis by waste input-output model

    Shinichiro Nakamura, Yasushi Kondo

    Journal of Material Cycles and Waste Management   4-1, 2-11  2002年

  • A non-homothetic globally concave flexible cost function and its application to panel data

    S Nakamura

    JAPANESE ECONOMIC REVIEW   52 ( 2 ) 208 - 223  2001年06月  [査読有り]

     概要を見る

    A new non-homothetic globally concave flexible cost function is introduced and applied to a panel of firms in the Japanese paper and pulp industry. This cost function is a mixture of the generalized McFadden form and the generalized Ozaki form due to Nakamura (1990). A generalized index of technical change is used in place of the standard quadratic form of time-trend. The estimated cost function satisfied global concavity, and the symmetry condition of the Slutsky matrix was not rejected. Homotheticity was strongly rejected.

  • Waste Input-Output Analysis of Disposal, Recycling, and Extended Life

    Shinichiro Nakamura, Yasushi Kondo

    IEEE Computer Society   814-819  2001年

  • 循環型社会におけるサーマルリサイクル

    中村愼一郎

    資源環境対策   37/5,482-488  2001年

  • Waste Input-Output Analysis of Disposal, Recycling, and Extended Life of Electric Home Appliances, in Second International Symposium on Environmentally Conscious Design and Inverse Manufacturing, Proceedings

    IEEE Computer Society   814-819  2001年

  • Waste input-output analysis of disposal, recycling, and extended life of electric home apppliances

    S Nakamura, Y Kondo

    SECOND INTERNATIONAL SYMPOSIUM ON ENVIRONMENTALLY CONSCIOUS DESIGN AND INVERSE MANUFACTURING, PROCEEDINGS   814-819   814 - 819  2001年  [査読有り]

     概要を見る

    Economic and emission effects of alternative life-cycle strategies for electric home appliances were analyzed by use of Waste Input-Output (WIO). The strategies consist of 1) landfilling, 2) conventional shredding with iron recovery, 3) integrated recycling with the recovery of metals, glass, and plastics, and 4) extension of products lives without and with increased maintenance and updating activities. It was found that strategy 3 outperformed strategies I and 2 in terms of both CO2 emission and landfill consumption. The result was robust to the variation of transport conditions. The overall increase in labor cost under strategy 3 turned out almost neutral. Strategy 4 outperformed strategy 3 in terms of environmental effects. The extent to which the reduced sales of new appliances were compensated by the increased demand for maintenance was found to have significant effects on the level of employment.

  • Thermal Recycling in a Closed-Loop Society

    Journal of Resources and Environment   37/5,482-488  2001年

  • 廃棄物の産業連関分析

    中村 愼一郎

    廃棄物学会誌   11 ( 4 ) 289 - 300  2000年07月

     概要を見る

    環境との調和を図りながら経済発展を実現する手段として, 循環型経済への変換が叫ばれている。循環型経済を設計するためには, 財と廃棄物の循環を巡る動脈と静脈の連関関係を定量的に把握することが極めて重要である。産業連関分析は, 動脈における財の流れを定量的に把握する手法として開発されてきた。これを廃棄物と財の循環をも把握するべく拡張することが出来れば, 上の目的に資する所大であると考えられる。この観点から, 産業連関分析とその廃棄物への応用を解説する。産業連関分析の簡単な解説に続いて, レオンチェフの廃棄物モデルとその派生モデルによる分析 (二酸化炭素分析, 環境統合勘定) を紹介する。続いて, 廃棄物に関する物質収支を踏まえた廃棄物産業連関表・モデルを紹介し, その物質フロー分析, 生態的足跡分析との関連, および国際産業連関表の活用可能性について述べる。

    DOI CiNii

  • 廃棄物処理と再資源化の産業連関分析

    廃棄物学会論文誌   第11巻2号、pp.84-93  2000年03月

  • Recycling of electrical home appliances: Its impacts on the economy and environment

    S Nakamura, Y Kondo

    ELECTRONICS GOES GREEN 2000 (PLUS): A CHALLENGE FOR THE NEXT MILLENNIUM, VOL 1, PROCEEDINGS     827 - 832  2000年  [査読有り]

     概要を見る

    In 1998, the Japanese government passed a law for the recycling of specified kinds of electrical home appliances, which is to be put in full operation in 2001. Under the law, the manufacturers of TV sets, refrigerators, washing machines, and air conditioners, who operate in Japan, are obliged to recycle specified percentage of discarded appliances. While the recycling is said to be technically feasible, uncertainty remains with respect to its overall effects on the environment and economy. Using the Waste Input-Output Model (WIO, [1]) we evaluated these effects, and found that the landfill consumption and carbon dioxide emission could be reduced without reducing the level of employment.

  • Inter-relationships between arterial-and venous sectors

    Journal of Waste Management Research   53/235,200-205  2000年

  • Input-Output Analysis of Waste Treatment and Recycling

    Journal of the Japan Society of Warte Management Experts   11/2,89-93  2000年

  • 動脈部門と静脈部門の相互連関

    全国都市清掃会議,神戸市    1999年12月

  • ライフスタイルと技術と廃棄物の連関分析:シュレッダーダストへの応用

    エコデザイン'99ジャパンシンポジウム 東京    1999年12月

  • 廃棄物産業連関モデル:広域処理と廃プラスチック高炉還元への応用

    第10回廃棄物学会研究発表会    1999年10月

  • リサイクル産業連関モデル:理論と応用

    環境経済・政策学会 1999年大会, 立命館大学    1999年09月

  • 廃棄物循環の線形経済モデル

    三田学会雑誌   92巻2号  1999年06月

  • An Extended Input-Output Modeling of the Flow of Waste

      Proceedings, Fifth International Symposium on East Asian Recycling Technology 工業技術院, 筑波  1999年06月

  • Input-Output Analysis of Waste Cycles

    理論計量経済学会西部大会, 高松大学    1999年04月

  • Input-Output Analysis of Waste Cycles

    First International Symposium on Environmentally Conscious Design and Inverse Manufacturing, Proceedings,   IEEE Computer Society, Los Ala  1999年02月

  • An Interindustry Approach to Analyzing Economic and Environmental Effects of the Recycling of Waste.

    Ecological Economics/Elsevier   28 (1)  1999年02月

  • An interindustry approach to analyzing economic and environmental effects of the recycling of waste

    Shinichiro Nakamura

    Ecological Economics   28 ( 1 ) 133 - 145  1999年01月

     概要を見る

    Recycling of waste reduces the demand for virgin materials, the amount of waste to be incinerated and/or landfilled, and also reduces emissions from these sources, however, it generates waste and emissions of its own. This paper presents a static inter-industry model for analyzing economic and environmental effects of the recycling of waste that is capable of accommodating these aspects of recycling. Waste can be classified into two major categories depending on the way it is generated: (1) those generated as 'undesired' by-products in the production process such as wastewater or sludge, and (2) those originally produced as goods but have turned to waste with the passing of time, such as old paper or discarded consumer durables. We are concerned with the second category of waste. This category of waste tends to be distributed over a wide geographical area because it is generated in the place of final use, whereas the first one is generated in the place of production. Since the issue of sorted collection will thus be a non-negligible element of any recycling program involving this category of waste, we treat the collection and recycling of waste as distinct activities, instead of their being put into a black box. In this respect, our model is an extension of Duchin, 1990, Structural Change and Economic Dynamics, 1, 243-262. We regard the amount of waste as a given stock, and do not consider the process of its generation. As an empirical illustration, we construct a numerical example for the recycling of old paper based on the Dutch NAMEA data for 1992, and analyze effects of alternative recycling scenarios on the industrial activity and emission of CO2. Each scenario consists of a set of parameters referring to the proportion of recycled goods in total input, the efficiency of waste collection, and the efficiency of recycling technology.

    DOI

  • An interindustry approach to analyzing economic and environmental effects of the recycling of waste

    S Nakamura

    ECOLOGICAL ECONOMICS   28 ( 1 ) 133 - 145  1999年01月  [査読有り]

     概要を見る

    Recycling of waste reduces the demand for virgin materials, the amount of waste to be incinerated and/or landfilled, and also reduces emissions from these sources, however, it generates waste and emissions of its own. This paper presents a static inter-industry model for analyzing economic and environmental effects of the recycling of waste that is capable of accommodating these aspects of recycling. Waste can be classified into two major categories depending on the way it is generated: (1) those generated as 'undesired' by-products in the production process such as wastewater or sludge, and (2) those originally produced as goods but have turned to waste with the passing of time, such as old paper or discarded consumer durables. We are concerned with the second category of waste. This category of waste tends to be distributed over a wide geographical area because it is generated in the place of final use, whereas the first one is generated in the place of production. Since the issue of sorted collection will thus be a non-negligible element of any recycling program involving this category of waste, we treat the collection and recycling of waste as distinct activities, instead of their being put into a black box. In this respect, our model is an extension of Duchin, 1990, Structural Change and Economic Dynamics, 1, 243-262. We regard the amount of waste as a given stock, and do not consider the process of its generation. As an empirical illustration, we construct a numerical example for the recycling of old paper based on the Dutch NAMEA data for 1992, and analyze effects of alternative recycling scenarios on the industrial activity and emission of CO2. Each scenario consists of a set of parameters referring to the proportion of recycled goods in total input, the efficiency of waste collection, and the efficiency of recycling technology. (C) 1999 Elsevier Science B.V. All rights reserved.

  • A Linear Economic Model of Waste Cycles

    Mita Journal of Economics   92/2,86-107  1999年

  • 線形経済モデルによる廃棄物処理の有効性分析

    第9回廃棄物学会研究発表会講演論文集   1  1998年11月

  • 廃棄物循環再利用の経済・環境効果の産業連関分析

    第8回廃棄物学会研究発表会講演論文集   1  1997年11月

  • Total Factor Productivity Growth and Technical Change: : The Japanese Chemical Industry 1968-1987

    Memorandum , Department of Economics, School of Economics and Commercial Law, Goeteborg University.   No 244  1997年11月

  • The Generalized Ozaki-McFadden Cost Function and its Application to Panel Data

    6th Biennial Conference on Panel Data,Amsterdam    1997年06月

  • An Interindustry Approach to Analyzing Economic and Environmental Effects of the Recycling of Waste

    現代政治経済研究所ワーキングペーパーシリーズ   9704  1997年04月

  • RATS による産業連関分析

    早稲田政治経済学雑誌   329  1997年01月

  • 廃棄物リサイクルの産業連関モデル

    早稲田政治経済学雑誌   328  1996年10月

  • The short-run structure of labor demand and commodity supply ina aputty-clay type model

    Waseda Economic Papers   35  1996年10月

  • The Generalized Ozaki-McFadden Cost Function and its Application to Panel Data

    現代政治経済研究所 ワーキングペーパー   9604  1996年06月

  • A nonohomothetic globally concave cost function with the general indexof technical change and its application to panel data

    早稲田大学現代政治経済研究所 ワーキングペーパー   9502  1995年10月

  • 生産構造の計量分析

    創文/創文社   366  1995年06月

  • 日独輸送機械及び電気機械産業生産性の分析

    早稲田政治経済学雑誌   321  1995年04月

  • AN ADJUSTMENT COST MODEL OF LONG-TERM EMPLOYMENT IN JAPAN

    S NAKAMURA

    JOURNAL OF APPLIED ECONOMETRICS   8 ( 2 ) 175 - 194  1993年04月  [査読有り]

     概要を見る

    A dynamic factor demand model is presented which pays special attention to the prevalence of a long-term employment relationship in Japan. The model is based on the representation of technology by a variable cost function with adjustment costs for employment and capital stock, where the variable cost consists of the sum of overtime costs and materials costs. With employment being quasi-fixed and scheduled hours institutionally regulated, short-run adjustments are mostly made by overtime hours. Application to a time-series data on the Japanese electrical machinery industry indicates quasi-fixity of capital and employment and reproduces short-run overshooting of overtime hours to compensate for the sluggish adjustment of employment.

  • PRODUCTIVITY IN MANUFACTURING-INDUSTRIES, CANADA, JAPAN AND THE UNITED-STATES, 1953-1986 - WAS THE PRODUCTIVITY SLOWDOWN REVERSED

    M DENNY, J BERNSTEIN, M FUSS, S NAKAMURA, L WAVERMAN

    CANADIAN JOURNAL OF ECONOMICS-REVUE CANADIENNE D ECONOMIQUE   25 ( 3 ) 584 - 603  1992年08月  [査読有り]

     概要を見る

    This paper analyses total factor productivity growth and trends in relative efficiency levels in the national Two-Digit Manufacturing industries of Japan, Canada, and the United States during the last quarter-century. The well-known slowdown in productivity growth rates in the 1973-80 period was a common phenomenon across the three countries but was felt most strongly in Japan and least in Canada. While the 1980s saw a pick-up in productivity growth over the slowdown period, growth in productivity has not returned to the pre-1973 level. The productivity slowdown and any subsequent increase in productivity growth rates have been correlated across industries in the three countries to a very high degree.

  • Triangulation of Japanese input-output tables with 175 sectors

    Shinichiro Nakamura, Jun Shinozuka

    Bulletin of Centre for Informatics, Waseda University   15   55 - 59  1992年06月  [査読有り]

     概要を見る

    The Japanese input-output tables for 1975, 80, and 85 with 175 endogenous sectors were triangulated using the algorithm of Simpson and Tsukui. The degree of obtained triangularity measured by a linearity index is about 0.9, and indicates the existence of significant hierarchy among 175 industries. Rank correlation coefficients of sectoral orderings are about 0.98, and indicate stability of the hierarchical structure over time.

  • Japan's challenge to Canadian manufacturing industries : Productivity growth and level

    Economic Studies Quarterly   43/4  1992年

  • Explaining Japan and US TFP Difference

    Economic Studies Quarterly   43/4  1992年

  • A NONHOMOTHETIC GENERALIZED LEONTIEF COST FUNCTION BASED ON POOLED DATA

    S NAKAMURA

    REVIEW OF ECONOMICS AND STATISTICS   72 ( 4 ) 649 - 656  1990年11月  [査読有り]

  • A dynamic model of factor demand with overtime as a variable input and its application to the Japanese electrical machinery industry

    Kokumin Keizai Zasshi   162/4  1990年

  • Impacts of robotization on the Japanese economy

    Mitsuo Saito, Shinichiro Nakamura

    Technological Forecasting and Social Change   35 ( 2-3 ) 167 - 177  1989年  [査読有り]

     概要を見る

    The introduction of robots leads to a reduction of direct labor, whereas it stimulates the investment activity of firms and thereby brings about a rise in indirect employment. This paper attempts to evaluate relative magnitudes of both effects of robotization on employment. The method of analysis depends on the application of an econometric model. The results of the survey at the individual firm level are also utilized. The forecast for the current five years (1985-1990) is that robotization will result in a net effect of a 23 thousand person decrease in employment. © 1989.

    DOI

  • Productivity and factor prices as sources of differences in production costs between Japan. Germany and the U. S.

    Economic Studies Quarterly   40/1  1989年

  • A flexible dynamic model of multiproduct technology for the West German economy

    Shinichiro Nakamura

    Journal of Applied Econometrics   1 ( 4 ) 333 - 344  1986年  [査読有り]

     概要を見る

    This paper tests symmetry and negativity of the Slutsky matrix for a system of demand functions derived from an aggregate model of multi product technology within a flexible dynamic framework. The model considers three inputs and three outputs, including imports and exports of intermediate goods. We derive a static demand model from a trans log cost function and specify the data generation process by a stationary ARX (1, 1) model. Results based on West German quarterly data indicate that the integrability conditions are not rejected when imposed on the ARX (1, 1) model, whereas they are rejected for all the less general dynamic models considered. Copyright © 1986 John Wiley &amp
    Sons, Ltd.

    DOI

  • A dynamic multisectoral model of production, investment and prices based on flexible cost functions.

    Vierteljahre sheft zur Wirtshaftsforschung   4  1986年

  • A TEST OF RESTRICTIONS IN A DYNAMIC SINGULAR DEMAND SYSTEM - AN APPLICATION TO THE IMPORT OF INTERMEDIATE GOODS IN WEST-GERMANY

    S NAKAMURA

    ZEITSCHRIFT FUR NATIONALOKONOMIE-JOURNAL OF ECONOMICS   45 ( 3 ) 313 - 330  1985年  [査読有り]

    DOI

  • A waste input-output life cycle cost analysis of the recycling of end-of-life electrical home appliances

    NAKAMURA Shinichiro, KONDO Yasushi

    Working paper series   310   1 - 26

     概要を見る

    Life cycle assessment (LCA) enables one to compare the environmental impact of alternative product systems, and identify the one with the least impact. However environmentally sound a product system is however, it cannot be widely introduced into the economy unless it is also economically affordable. Without a wide ranging introduction into the economy, its potential to reduce environmental impact remains unexploited. The aspect of cost is thus of great importance for assessing the economic affordability and hence the economic sustainability of a product system which is found environmentally sound by an LCA. The aspect of cost that maters here is not limited to the conventional one referring to that of manufacturing only, but should be a broader one referring to the life cycle cost that encompasses the use and the end-of-life cost as well. Life cycle costing (LCC) is concerned with the comparison of life cycle costs among alternative product systems. This paper presents a new methodology of LCC, WIO-price model, that builds upon the WIO quantity model, a hybrid LCA tool developed by us that is specially designed for application to waste management (Nakamura and Kondo, 2002). The ap

    CiNii

  • The Generalized Ozaki-McFadden Cost Function and its Application to a Pooled Data on the Japanese Chemical Industry

    Waseda Economic Papers   34

  • Analyzing productirity level of transport nachinery and electrical mochinery industries in Japan and Germany

    Waseda Journal of Political Science and Economics   /322,189-214

▼全件表示

書籍等出版物

  • Waste Input-Output Analysis: Concepts and Application to Industrial Ecology

    Shinichiro Nakamura, Yasushi Kondo

    Spinger  2009年02月 ISBN: 9781402099014

  • ライフサイクル産業連関分析

    中村愼一郎他

    早稲田大学出版部  2007年10月

  • 廃棄物経済学をめざして

    中村愼一郎

    早稲田大学出版部  2002年

  • Recycling of electrical home appliances : its impacts on the economy and environment

    Electronics Goes Green 2000+, Proceedings  2000年

  • Adjustments of Employment and Working Hours under Long-term Employment

    The Frontier of Research in Japanese Economy, Yuhikaku  1993年

  • An interindustry translog model of prices and technical change for the West German Economy

    Lecture Notes in Economics and Mathematical Systems  1984年

▼全件表示

Misc

  • IO-MFA and Thermodynamic Approach for Metal Recycling

    Kenichi Nakajima, Kazuyo Matsubae, Yasushi Kondo, Shinichiro Nakamura, Tetsuya Nagasaka

    REWAS 2013 Enabling Materials Resource Sustainability     412 - 413  2013年02月

    DOI

  • Development of Efficient Recycling System for Steel Alloying Elements in End of Life Vehicles

    Hajime Ohno, Kazuyo Matsubae, Kenichi Nakajima, Shinichiro Nakamura, Testsuya Nagasaka

    REWAS 2013 Enabling Materials Resource Sustainability     414 - 422  2013年02月

     概要を見る

    © 2013 The Minerals, Metals &amp; Materials Society. All rights reserved. Special steels, which have been imparted various properties by the addition of alloying elements, have become increasingly important as materials for human life in recent years. As the largest industrial consumer of special steel materials, the motor vehicle industry requires large volumes of various types of special steel for vehicle production. Scrap containing base metals and alloying elements is generated from end-of-life vehicles (ELVs). In current scrap treatment processes, alloying elements in steel materials are rarely considered, instead becoming impurities in steel recycling processes at electric arc furnaces (EAF) and losing their worth. In this study, with the aim of avoiding loss of useful steel alloying elements, we discuss effective treatment of ELVs for efficient recycling and use of steel alloying elements using waste input-output material flow analysis (WIO-MFA).

    DOI

  • Synthesis of material flow analysis and input–output analysis

    Shinichiro Nakamura

    Thermodynamics and the Destruction of Resources   9780521884556   334 - 362  2011年01月  [査読有り]

     概要を見る

    © Cambridge University Press. Introduction For a model of a production process to be valid in the real world, it has to take proper account of the principles of thermodynamics. Production models in economics are no exception. The conservation of mass requires that proper attention be paid to the mass balance between inputs and outputs entering and leaving a given production process. An increase of entropy implies the generation of process waste in the production phase and the reduction in the purity of materials in the use and end-of-life (EoL) phases. Because process waste is generated in the production phase, it should be classified as an output if the mass balance between inputs and outputs is to be established. The reduction in the purity of materials in the use phase is relevant for materials made of polymers, such as paper, textile, and plastics, whose chemical bindings loosen over time. On the other hand, for metals such as iron, copper, or aluminum, such a decline in quality in the use phase will not occur [except for possible corrosions (oxidization)] because these metals are elements. In fact, it is not the use phase but the EoL phase in which a serious reduction in the quality of metal materials can occur because of the mixing-up of diverse metal elements or the “contamination” of pure elements with other elements in minor quantities (tramp elements).

    DOI

  • Rare-metal flow in steel cycle

    Kazuyo Matsubae-Yokoyama, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

    Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan   95   759 - 765  2009年12月  [査読有り]

    速報,短報,研究ノート等(学術雑誌)  

  • Material Flow Analysis of Polyvinyl Chloride in Japan based on the WIO-MFA Model

    Shinichiro Nakamura, Kenichi Nakajima, Yoshie Yoshizawa, Kazuyo Matsubae-Yokoyama, Tetsuya Nagasaka

    Journal of Industrial Ecology   13 ( 5 ) 706 - 717  2009年10月  [査読有り]

    担当区分:筆頭著者

    記事・総説・解説・論説等(学術雑誌)  

    DOI

  • 経済統計を利用したマテリアルフロー分析:WIO-MFAモデルの開発と適用

    中島 謙一, 南斉 規介, 中村 愼一郎, 松八重 一代, 長坂 徹也

    日本LCA学会研究発表会講演要旨集   2009 ( 0 ) 17 - 17  2009年

     概要を見る

    発表者らはこれまで、産業連関表を利用したマテリアルロー分析モデルとしてWIO-MFAモデルの開発に携わるとともに、金属やプラスチックのマテリアルフロー分析に適用してきた。本研究では、産業連関表および国家統計・業界統計などを活用した多元他部門マテリアルフロー分析手法としてのWIO-MFAモデルの構造を紹介すると共に、適用例として、鉄を例に取り上げた国際貿易に伴うわが国の金属資源の直接・間接輸出入ネットワークに関する研究を紹介する。

    CiNii

  • Material flow analysis on steel recycling considering accompanying substances

    Kazuyo Yokoyama, Kenichi Nakajima, Shinichiro Nakamura, Tetsuya Nagasaka

    Nihon Enerugi Gakkaishi/Journal of the Japan Institute of Energy   87   247 - 253  2008年04月

     概要を見る

    The demand for iron and steel materials has been increasing due mainly to the rapid economic growth of BRICs countries, with approximately 2 billion tons of crude steel being produced per year in the whole world. Under this situation, the production of crude steel in Japan is also increasing. As a result of this, the significance as an iron source of iron and steel scraps is increasing as well. Scrap recycling, however, is subject to some problems, such as unstable supply conditions, contamination by impurities, and so on. Given the huge volume and the wide variety of steel products being used in our society, information about the location, the volume, and the properties of steel materials is difficult to obtain. Owing to its huge volume, the stock of steel materials in our society plays an important role not only as a major future source of iron, but as a carrier of accompanying elements as well. From the view point of an efficient management of rare resources, it is of importance to obtain information about the flow of accompanying elements that are associated with the flow of iron and steel materials. We have surveyed the current situation of the generation and recycling of iron and steel scrap in Japan, and analyzed the usage of steel scrap in each category of steel products quantitatively based on the iron and steel statistics. Furthermore, the possible effects of the diffusion of rare metals in iron scrap, and its effects on the efficiency of steel production were examined by scenario analysis based on waste input output model (WIO). The results indicate that importance of sorting scrap on the basis of the composition of alloying elements.

  • 随伴元素成分を考慮した鉄鋼リサイクルフロー分析

    横山一代, 中島謙一, 中村愼一郎, 長坂徹也

    日本エネルギー学会誌   87 ( 4 ) 243 - 249  2008年04月

    記事・総説・解説・論説等(学術雑誌)  

  • Substance Flow Analysis of Zinc Associated with Iron and Steel Cycle in Japan, and Environmental Assessment of EAF Dust Recycling Process

    Kenichi Nakajima, Kazuyo Matsubae-Yokoyama, Shinichiro Nakamura, Satoshi Itoh, Tetsuya Nagasaka

    ISIJ INTERNATIONAL   48 ( 10 ) 1478 - 1483  2008年

     概要を見る

    Japanese zinc production in 2005 was 6.75x10(5) t, and domestic demand of zinc was 4.82x10(5)t. The main use of metallic zinc is in the surface coating of steel and the metal accounts for 62.8 % of the domestic demand. The purposes of this study are as follows: (1) to identify the material flow of zinc associated with steel production, and (2) to estimate the environmental effects (energy consumption and CO2 emission reduction) of some intermediate dust treatment processes.
    The major conclusions are (a) in Japan, 6.16x10(6) t of blast furnace/converter dust was generated in 2000, and this product contained 2.20x10(4) t-Zn. 0.433x10(6) t of EAF dust was generated and this dust contained 8.86x10(4) t-Zn, and (b) 9.57 MJ of energy is required for producing I kg of zinc oxide by the Waelz process using EAF dust, and the estimated amount of CO, emission in this process is 1.49 kg-CO2. On the other hand, if the LAMS process proposed by the authors is employed, it is estimated that there will be a reduction of 1.70 MJ in energy consumption and a reduction of 0.14 kg-CO2 in CO2 emissions.

    DOI

  • Environmental life cycle costing

    Gerald Rebitzer, Shinichiro Nakamura

    Environmental Life Cycle Costing     35 - 58  2008年01月

     概要を見る

    © 2008 by the Society of Environmental Toxicology and Chemistry (SETAC). The rationale behind environmental LCC is presented, with a specific focus on key issues that one must consider prior to, and during, the assessment. Specific discussions on the appropriate system boundaries, as well as other links to life cycle assessment, are discussed. These methodological issues include the definition of the functional unit and the most appropriate means for data aggregation. The interpretation of the results and the use of portfolio presentations of LCC as a function of the key environmental impact are recommended. Input-output-based LCC is also presented and applied to the cross-cutting washing machine case.

    DOI

  • Evaluating eco-efficiency of appliances by integrated use of hybrid LCA and LCC tools

    Shinichiro Nakamura

    Advances in Life Cycle Engineering for Sustainable Manufacturing Businesses     445 - 448  2007年

     概要を見る

    Airconditioners are the appliance with the largest share of electricity consumption in Japanese households. In our preceding study, it was found that the high-end model (with the highest environmental performance with regard to Global Warming Potential and landfill consumption) turns out to be the one with the lowest life cycle cost, and the low-end model (with the lowest environmental performance) the one with the highest life cycle cost. This paper is concerned with investigating if the above finding still holds for more recent data, say for 2005, and also in analyzing possible changes that have occurred since 2002 from the perspective of eco-efficiency. Compared with the previous results, we notice a significant reduction in the cost at the use phase due to the convergence in efficiency at the use phase, and the resulting reduction in life-cycle costs among alternative models. There was thus a significant increase in eco-efficiency between 2002 and 2005 in terms of both CO, and landfill consumption.

  • 動学的廃棄物産業連関モデルによるリサイクルの持続可能性評価

    横山一代, 中村愼一郎, 長坂徹也

    まてりあ   46 ( 1 )  2007年01月

    記事・総説・解説・論説等(学術雑誌)  

    DOI

  • Material flow analysis of metals based on the waste input-output model (WIO-MFA model): Application to material cycle of iron and steel

    Kenichi Nakajima, Shinichiro Nakamura

    JOURNAL OF THE JAPAN INSTITUTE OF METALS   70 ( 8 ) 618 - 621  2006年08月

     概要を見る

    Material Flow Analysis (MFA) has been widely used to identify and trace the flow of materials and substances. Within the frame work of the Waste Input Output (WIO) model (Nakamura and Kondo, JIE, 2002), we have developed a new methodology of MFA, the Waste Input-Output Material Flow Analysis, reported elsewhere (WIO-MFA) (Nakamura and Nakajima, Materials Trans., 2005). In this study, the methodology is applied for the purpose of analyzing the material cycle of iron and steel in Japan. First, we discuss issues of data that we developed for estimating the WIO-MFA table with 395 sectors, and then proceed to the estimation of the metal composition of specific products. Our major concern is the composition of recycled Fe components in the products.

    DOI

  • Waste input-output material flow analysis and its application to quantity metals

    Shinichiro Nakamura, Kenichi Nakajima

    JOURNAL OF THE JAPAN INSTITUTE OF METALS   70 ( 6 ) 505 - 510  2006年06月

    記事・総説・解説・論説等(学術雑誌)  

     概要を見る

    This paper develops a theoretical model of material flow analysis (MFA) within the framework of the Waste Input-Output model (WIO) (Nakamura and Kondo). The model is developed based on two fundamental ingredients: yield ratios and the degree of fabrication. In manufacturing process, multiplication of physical inputs by the yield ratios gives the portion that enters physical outputs, with the rest being discarded as process waste without entering outputs. In input-output analysis, the degree of fabrication can be visualized as triangularity of the input coefficients matrix (goods of lower degree of fabrication can enter those of higher fabrication, but the reverse does not hold), which is known to emerge through an appropriate reordering of sectors. Application to the Japanese 10 data indicates that the model can provide accurate estimates of the weight as well as the composition of metals (Fe, Cu, Ph, Zn, and Al) used in a passenger car. The model is also used to estimate the major final use categories (household consumption, public consumption, capital investment, inventory investment, and export) of metals.

    DOI

  • 廃棄物産業連関モデルに基づくハイブリッドLCA

    横山一代, 長坂徹也, 中村愼一郎

    ふぇらむ   10 ( 11 ) 16 - 21  2005年11月

    記事・総説・解説・論説等(その他)  

  • 産業連関分析による製品材料組成の推定:ベースメタル

    中村 愼一郎, 中島 謙一

    廃棄物学会研究発表会講演論文集   16   70 - 72  2005年10月

    CiNii

  • 廃棄物処理広域化の環境影響評価:廃棄物産業連関線形計画モデルの地域間産業連関表への応用

    近藤 康之, 加河 茂美, 中村 慎一郎

    廃棄物学会研究発表会講演論文集   16   73 - 75  2005年10月

    CiNii

  • Inter-regional waste input-output linear programming model and its application to the Japanese regions

    Yasushi Kondo, Shigemi Kagawa, Shinichiro Nakamura

    Fourth International Symposium on Environmentally Conscious Design and Inverse Manufacturing, Proceedings   2005   694 - 698  2005年

     概要を見る

    This paper presents a case study to show how beneficial a regional concentration of waste treatment and disposal is. The key method, an inter-regional counterpart of the waste input-output linear programming model (Kondo and Naka-mura, Economic Systems Research, 2005), is developed, and applied to the 1995 Japanese 9-region inter-regional waste input-output table. One of the important problems to solve in Japan is the shortage of landfill site, which is partly due to the uneven distribution of landfill sites. The results indicate that, at the cost of the increase of CO2 emission only by 0.2%, the shortage of landfill site in some regions is alleviated by regional concentration. It is expected that the developed method can support realistic decision-making about the regional strategies of waste management.

    DOI

  • Waste Input-Output Analysis and Optimization of Waste Management

    Yasushi Kondo, Shinichiro Nakamura

    IEEJ Transactions on Electronics, Information and Systems   124 ( 10 ) 2187 - 2194  2004年

     概要を見る

    A decision analytic model of life cycle assessment (LCA) for waste management based on the waste input-output (WIO) model is presented. The resulting WIO-LP model can help environmental decision making with regard to choosing an "optimal" waste management from among a set of possible technological alternatives to meet given policy objectives under consideration of given physical, economic, and institutional constraints. Its implementation to Japanese data reveals the presence of a trade-off relationship between the reduction of CO2 emission and the consumption of landfill capacity. © 2004, The Institute of Electrical Engineers of Japan. All rights reserved.

    DOI

  • Waste input-output analysis of disposal, recycling, and extended life of electric home apppliances

    S Nakamura, Y Kondo

    SECOND INTERNATIONAL SYMPOSIUM ON ENVIRONMENTALLY CONSCIOUS DESIGN AND INVERSE MANUFACTURING, PROCEEDINGS     814 - 819  2001年

     概要を見る

    Economic and emission effects of alternative life-cycle strategies for electric home appliances were analyzed by use of Waste Input-Output (WIO). The strategies consist of 1) landfilling, 2) conventional shredding with iron recovery, 3) integrated recycling with the recovery of metals, glass, and plastics, and 4) extension of products lives without and with increased maintenance and updating activities. It was found that strategy 3 outperformed strategies I and 2 in terms of both CO2 emission and landfill consumption. The result was robust to the variation of transport conditions. The overall increase in labor cost under strategy 3 turned out almost neutral. Strategy 4 outperformed strategy 3 in terms of environmental effects. The extent to which the reduced sales of new appliances were compensated by the increased demand for maintenance was found to have significant effects on the level of employment.

    DOI

  • Input-output analysis of waste cycles

    S Nakamura

    FIRST INTERNATIONAL SYMPOSIUM ON ENVIRONMENTALLY CONSCIOUS DEGIGN AND INVERSE MANUFACTURING, PROCEEDINGS     475 - 480  1999年

     概要を見る

    Any production activity including recycling of waste materials and consumption emits waste. This paper presents an accounting framework describing the interdependence between the flow of goods and waste among different sectors of the economy, and derives a linear input-output model from it that can be used for analyzing the relationships among environmental loads, technology/institutions, and life-style. The accounting framework is used to analyze the MSW flow of a city in Hokkaido with an extensive waste management policy. The input-output model is used to evaluate the effectiveness of the policy with respect to the requirements for landfill capacity and energy.

    DOI

  • An adjustment cost model of long‐term employment in Japan

    S. Nakamura

    Journal of Applied Econometrics   8 ( 2 ) 175 - 194  1993年

     概要を見る

    A dynamic factor demand model is presented which pays special attention to the prevalence of a long‐term employment relationship in Japan. The model is based on the representation of technology by a variable cost function with adjustment costs for employment and capital stock, where the variable cost consists of the sum of overtime costs and materials costs. With employment being quasi‐fixed and scheduled hours institutionally regulated, short‐run adjustments are mostly made by overtime hours. Application to a time‐series data on the Japanese electrical machinery industry indicates quasi‐fixity of capital and employment and reproduces short‐run overshooting of overtime hours to compensate for the sluggish adjustment of employment. Copyright © 1993 John Wiley &amp; Sons, Ltd.

    DOI

▼全件表示

受賞

  • 日本鉄鋼協会 学術貢献賞(浅田賞)

    2012年12月  

  • 鉄鋼環境基金 理事長賞

    2012年09月  

  • 日本LCA学会功績賞

    2012年03月  

  • リサイクル技術開発本多賞

    2006年01月  

  • 廃棄物学会論文賞

    2001年  

  • GEFFRUB 賞

    1983年06月   ボン大学  

▼全件表示

共同研究・競争的資金等の研究課題

  • 希少合金元素の高効率リサイクルを目指した多元物質ストック・フロー解析モデルの開発

    研究期間:

    2019年04月
    -
    2022年03月
     

     概要を見る

    持続可能社会の実現手段として循環経済(サーキュラーエコノミー)の実現が求められている。循環経済をめぐる議論は多岐に渡るが、その定量的基礎として欠かせない全経済的な物質ストック・フローの長期的な挙動を統一的、一般的かつ定量的に捉えた手法は開発されていない。本研究の目的は、多物質・多元素を考慮した動的物質ストック・フロー解析モデルを世界に先駆けて開発し、その実証性をとくに国家備蓄対象となっている鉄鋼合金元素について検証することである。これにより、リサイクルの質、部品リユース、リマニュファクチャリング可能性等を定量的情報に基づいて検討し、循環経済に係る政策立案の支援に資することが期待される

  • 多元物質フロー解析モデルの開発と随伴元素成分を考慮した鉄鋼リサイクルへの応用

    研究期間:

    2015年04月
    -
    2018年03月
     

     概要を見る

    鉄鋼スクラップは、発生量のほぼ全量がリサイクルされているものの、鋼材に含まれる合金元素が有効利用されているとは言えない。合金元素を有効利用できるリサイクルを促進するために、多物質・多元素を同時に考慮できる物質フロー解析のための数理モデルを開発した。開発したモデルをシナリオ分析に応用して、スクラップの分別を徹底することによる合金元素リサイクルの可能性、および、それによって節約されるエネルギーを指標としてリサイクルの質を考慮することの重要性を指摘した

  • 金属資源利用・散逸時間経路及びその温暖化ガス排出の廃棄物産業連関

    研究期間:

    2010年04月
    -
    2013年03月
     

     概要を見る

    金属資源の持続可能な保全にはリサイクルが重要である.元の用途へのリサイクルが望ましいが,解体時の異種金属混合のため,元より要求の低い用途に使わることが少なくない.その結果,追加的な温暖化ガスなどの環境負荷が発生する.この環境負荷を推定する手法を開発し,自動車に使われる鉄鋼に応用した.破砕・選別技術の高度化によるスクラップ品質向上が自動車生産に関わる温暖化ガスを少なからず低減できることを定量的に明らかにした. 関連し,金属素材が廃棄・回収・リサイクルを経て用途を変遷していく過程を定量的に説明する数学モデルを開発した

  • 循環型社会に向けた総合的技術開発

    文部科学省 

    研究期間:

    2001年
    -
    2005年
     

  • サステナビリティ指標としての物質・材料フロー

    研究期間:

    2003年
    -
     
     

  • 製品等ライフサイクル二酸化炭素排出実証等技術開発」プロジェクトにおける廃家電処理の評価手法開発

    研究期間:

    2003年
    -
     
     

  • 廃棄物産業連関を用いた廃棄物処理費用分析

    研究期間:

    1999年
    -
    2001年
     

  • 廃棄物処理の経済分析

    研究期間:

    1996年
    -
    2000年
     

  • 廃棄物循環分析用産業連関表を用いた廃棄物処理費用負担制度の分析

     概要を見る

    動脈(財生産)部門と静脈(廃棄物管理)部門の間の財と廃棄物の循環を巡る相互依存関係を定量的に把握する勘定体系として廃棄物産業連関表の概念を提唱し,これに沿って平成7年度廃棄物産業連関表を開発した.この表は製造業を中心とする70の動脈部門,一般廃棄物と産業廃棄物からなる30種類の廃棄物,および焼却・破砕・埋め立ての廃棄物処理産門から構成されている.焼却はさらに廃熱利用・残差処理形態によって細別されている.この表はすでに昨年度までに開発した平成2年表を更新したものであるが,今後の外部公開を目指して作成手続きをマニュアル化した.これをデータベースとし,廃棄物処理に関わる工学モデルを入れ子とした統合LCAツールとしての廃棄物産業連関モデルをMATLABシステムとして開発した.同モデルを用い,平成13年4月から本格施行された「家電リサイクル法」の評価を行った.家電リサイクルの実行が直接埋め立てや従来型破砕に比べ,最終処分場消費を削減することはもちろん,温暖化ガスとされる化石燃料起源の二酸化炭素排出を全体として削減する,とする結果が得られた.また,補修・メンテナンスを通じる製品長寿命化の効果も評価した.消費支出の低下をともなう長期使用は雇用に悪影響を持つ.これに対し,支出を低下させない積極的な製品機能アップデートのもとでは雇用を悪化させることなく,リサイクルを大幅に上回る環境負荷軽減効果が得られる.LCA的に環境に好ましい製品・技術であっても,これが社会に受容されるためには経済的整合性を持つ必要がある.これに対処するために,WIOモデルの双対として費用面を考慮した価格モデルを作成した.広域化処理についての試算は,広域化が環境負荷を下げるのみでなく,収集方式によっては費用を下げる可能性も持つことを示している

  • 素材産業をプラットホームとした再生可能エネルギー・資原の創成

     概要を見る

    本研究では、我国における物質フローのひとつの巨大ハブとみなせる製鉄所を中心に、その周辺地域をひとつのユニットと捉え、ユニットトータルでの資源エネルギー流入量極少化、廃棄物流出量ミニマムを目指したシステム設計を目指した。すなわち、単なる「廃棄物処理」から「ある地域内での物質やエネルギー循環の有効利用、再生可能エネルギー・資源の創成」へとターゲットを高度化し、他産業や民生・運輸業を包含した各種産業間の連携・融合による「エコ・タウン化」設計を行う場合、鉄鋼等素材産業をメインプラットホームとすることが、エネルギー・マテリアルフローおよび技術・インフラの点から最も合理的であると言える。このような観点から、本研究では、素材産業をプラットホームとした再生可能エネルギー・資源の創成を目指し、製鉄所を中心とした特定地域内における未利用中低温排熱および再資源化可能な難処理廃棄物に関する実態調査を行い、学際的にエコ・タウン実現のための要素技術開発やそのゴールイメージの具体化を試みた。まず製鉄所などの素材産業をプラットホームに据えた周辺地域内をエコ・タウンとして設定し、その内外でのマテリアルフロー、エネルギーフローを精査した。その上で再生可能な資源・エネルギーを抽出し、具体的な再生可能プロセス・システム設計を、(1)技術的可能性と要素研究必要項目の検討、(2)需給バランスの適正化、(3)経済性およびリスク評価、の3つの観点から調査・検討した。その結果、粗鋼年産800万トンクラスの製鉄所を中心に、産業間リンクを適切に設定できれば、膨大な量が見込まれる未利用中低温排熱(スラグ顕熱、コークス、スラブ冷却熱等)、現状では低価値でしか利用されていない有価物(ダスト、スラグ、廃木材バイオマス等)、不規則に大量発生が予想される難処理廃棄物(マットレス、肉骨粉、廃船等)を再生可能エネルギー、資源として受け入れ可能であることが示された。以上の成果を踏まえ、本年度は「特定領域研究」の新規発足研究領域として応募することを計画している

  • 廃棄物産業連関分析に基づくマテリアルフロー分析モデルの動学化とその応用

     概要を見る

    製品ライフサイクルに関わる国民経済全体における多元マテリアルフローを記述する多部門数理モデルを開発した.このモデルを用いることで,非鉄製錬副産物として得られる貴・希少金属の生産過程を考慮したリサイクル可能性,リサイクルにおける多元素混合によるスクラップ品質劣化などを産業連関分析の枠組みで行うことが可能になる.日本におけるポリ塩化ビニールフローの同定,鉛フリーハンダ普及の銀資源への含意,易分解ネジとスクラップ品質の温暖化ガス効果,について応用分析を行った

▼全件表示

特定課題研究

  • 合金元素動的MFAモデルの開発

    2015年  

     概要を見る

    これまで,動的MFA に資するモデルMaTrace (Nakamura et. al., Environmental Science &amp; Technology, 2014, 48 (13), pp 7207-7214) を開発したが,それはいくつかの弱くない制約条件を受けている。その一つが,使用済み製品から発生するスクラップに対し,常にそれを丁度吸収するだけの需要が存在する仮定である。これは,多くの動的MFA研究において採用されているが,日本が鉄スクラップの輸出国であるといった現実を分析するには適切ではない。この問題に対処するため,MaTraceを廃棄物産業連関(WIO, Nakamura and Kondo, Journal of Industrial Ecology Vol. 6, No.1, pp.39-64, 2002.)の枠組みに入れ,最終需要からのend of life products をWeibull 分布で記述し,製品マテリアル組成をスクラップに変換する転換行列を介すことで製品からスクラップへのマテリアルフローを表現することができた。

  • 廃棄物地域産業連関最適化モデルの開発

    2002年   栗山 浩一

     概要を見る

    これまでに筆者らは,伝統的な産業連関表・モデルを廃棄物管理諸策の分析に適用可能なように拡張した廃棄物産業連関表・モデルを開発してきた。 また,シナリオ分析の方法により,環境・経済への影響評価についての 定量分析 (LCA) を行ってきた。この分析モデルを最適化問題のかたちへと拡張し,「最適な」廃棄物管理策探索の枠組みを提供することを主目的とする。 固定投入・排出係数を前提とすると,これまでの廃棄物産業連関分析モデルは線形方程式系として表現される。 解の一意性確保のためには,生産物 (変数) と生産技術 (係数行列の列) とが 一対一に対応しなければならない。 したがって,廃棄物処理・再資源化等の代替的技術の導入は 別の係数行列として表現され,新たに方程式系を解く必要が生じる.モデルを線型方程式系から線形計画問題へと拡張することで, この煩雑さを解消し,シナリオ選択における恣意性を排除することが出来る。 加えて,政策目標に即した目的関数 (例えば,最終処分場消費最小化) を設定することで,「最適な」廃棄物管理計画の策定が可能となる。最適な」廃棄物管理計画探索の枠組みを提供するだけでなく, 既存モデルでは困難であったシナリオ (温暖化ガス排出量削減目標など) が 自然なかたちで容易に導入可能となった。応用事例として,筆者らが開発した廃棄物産業連関表データを用い,厨芥のメタンガス化発電(残渣は堆肥利用),廃プラスチックの高炉還元利用,および焼却の広域化を選択しとし,目的関数としてCO2および最終処分場消費量を設定した分析を行った。埋立容量は最大で25%削減可能であり,その場合,CO2 も0.9% 削減される。CO2は最大で 1.9% 削減できるが,最終処分場消費削減を優先すると 0.9%しか削減されない。その一方で,CO2は最大で 1.9%削減できるが,その場合,埋立容量は7%以上増加してしまう。埋立容量削減を優先しても CO2排出が基準値より増加することはない。しかし,逆に CO2排出削減を優先すると埋立容量が増加してしまう,という意味で相反関係(トレードオフ)の存在が見いだされた。

  • 廃棄物循環分析用IO表の推定とゼロエミッション化の分析

    2000年  

     概要を見る

     財の生産と消費は不可避的に廃棄物を発生させる。静脈部門で適正処理・処分を経た廃棄物は、最終的に「環境負荷因子」として環境に放出される。静脈部門はその活動のために動脈部門からの財投入を必要とするが、一方で、それ自身廃棄物を発生させる。又、廃棄物再資源化は静脈から動脈への財供給である。動脈部門と静脈部門との間の財と廃棄物の循環を巡る、投入・産出・排出・処理・処分の相互依存関係を数量的に把握する分析装置として「廃棄物産業連関勘定及びモデル」を開発した。廃棄物産業連関の概念を既存研究との関連も含めて明確にし、理論的展開方向をで示した。全国表の推定作業を通じて各種統計資料からの廃棄物産業連関表の推定方法のマニュアル化を行い、Excelをインターフェースとして用いる廃棄物産業連関モデルのMATLABシステムを開発している。平成7年度の我が国公表産業連関表等を用いて、60産業部門、24種類の廃棄物、及び破砕・焼却から溶融・埋立までの廃棄物処理・処分部門からなる全国規模の廃棄物産業連関表モデルを推定した。応用として、広域化による集中処理・ごみ発電、廃プラスチックの高炉還元利用等が、産業生産活動・最終処分量・二酸化炭素排出量に及ぼす効果を評価検討した持続的経済社会の実現を目指す廃棄物管理政策にあっては、動脈と静脈の連関を考慮した全体的な環境負荷軽減を計ることが必要である。廃棄物産業連関は、中村者がこの目的に資するために独自に開発した物で、廃棄物発生のみならず廃棄物変換過程としての廃棄物処理と再資源化・処理に伴う動脈との連関を明示的に扱っている点、及び廃棄物処理に関して工学的モデルを入れ子の形で用いている点において、類似研究であるレオンチェフの公害除去産業連関モデル(及びその発展型)やSNAに基づく環境・経済統合勘定NAMEAと比較して大きな特色がある。

  • 廃棄物循環再利用多部門線形モデルにおける資源散逸条件の理論的実証的分析

    1998年  

     概要を見る

     理論的分析:①再資源化を含む生産モデルにおいて重要な資源散逸条件(鷲田豊明・Georgescu-Roegen)を線形多部門モデルについて導出した。②複数の廃棄物及び廃棄物処理過程と再資源化過程を整合的に記述する産業連関形式の廃棄物循環勘定体系を開発した。③この勘定体系に依拠した分析用線形モデルを導出した。①では鷲田豊明の結果を拡張し、②ではオランダ統計局が進めている NAMEA の簡略形と見なされる勘定体系を得た、③では、従来、不等式を含む線形計画法として解かざるを得なかった問題を、廃棄物適正処理情報から得られる変換係数を用いて等式体系として解けることを示した。 実証的分析:①全国一の一般廃棄物の再資源化率を誇る北海道のF市について聞き取り・視察を行い、同市についての廃棄物循環勘定を作成し、拡張産業連関モデルを推定し、堆肥化とRDF化を中心とする同市の廃棄物処理政策を埋立処分場への負荷と化石燃料消費の観点から評価した。F市廃棄物政策の際だった特徴は可燃ごみの再資源化にあるので、分析対象を可燃ごみに限定した。1996年の排出割合をコントロールとし、排出割合について以下の三シナリオを想定した1 [シナリオ 1: 再資源化無し] 全ての可燃ごみは焼却される2 [シナリオ 2: RDFのみ] RDFの割合はコントロールと同じだが、それ以外は全て焼却される3 [シナリオ 3: 有機肥料のみ]有機肥料のの割合はコントロールと同じだが、それ以外は全て焼却される再資源化を全く行わず[シナリオ1] "全量単純焼却 → 焼却灰埋立" とすると、単純焼却量は 132% 増加し埋立処分量も26%増加する。生ゴミを単純焼却しRDFのみ生産する[シナリオ2]場合、単純焼却量は89%増加し埋立は28%増加する。これに対してRDFごみを単純焼却し有機肥料のみ生産する[シナリオ3]場合には、焼却量が43%増加するのに対して、埋立量は微減する(RDF を生産しない方が埋立が微減するのは、RDF生産による他部門への生産誘発を通じる埋立誘発が微減するためと考えられるが、僅かな値なので無視する)。すなわち、再資源化を一切行わないと焼却量は約2.3倍に増えるが、その約7割は生ごみの再資源化を行わないために生じる。生ごみからの有機肥料生産は、埋立処分の減量対策として極めて有効に機能しているのである。 次に、RDFについてのエネルギー的な有効性を検討する。エネルギー投入の尺度として、各シナリオの下で誘発される石油・石炭製品と電力の生産額合計を用いた。F市の焼却炉では助燃が行われていないので、投入ベクトルにおけるエネルギー投入が焼却量に比例するとは考えにくい。従って、エネルギー必要量から焼却量の増加に比例する部分を除いた方が適当であると考えられるので、表の数値は焼却に関する部分を除いている。エネルギー投入は再資源化を全く行わない[シナリオ1]と0.006%と僅かではあるが減少する。しかし、RDFに限定すると[シナリオ2]エネルギー投入は0.07%減少する事から、RDF事業が少なくともエネルギー的に有効であることがわかる。この意味で、F市のRDF化事業は廃棄物処理事業ではなくて生産事業である。この結果は、工学的な見地から廃棄物処理関連部門に限定してRDFのエネルギー分析を行った金贏載、松藤敏彦、田中信寿(1995)の結果と整合的である。

  • 廃棄物処理と再利用の産業連関分析

    1997年  

     概要を見る

    1 従来の産業連関表に、廃棄物発生・処理・循環再利用を加えて拡張するための理論的検討を行った。特に、廃棄物ストックを所与としたときに、その循環再利用と廃棄に関わる環境負荷を求めるための線形模型を作成し、オランダNAMEAデータによってその挙動を検討した。2 実証モデル作成の準備として、自治体収集ゴミの再資源化率が6割近いという北海道富良野市の現地視察を行った。収集した資料を基に、同市についての廃棄物発生・循環再利用・廃棄処分の流れを記述する廃棄物勘定を、前出拡張産業連関模型の応用する形で作成する事を試みた。3 廃棄物発生・循環再利用を含む生産模型においては、Georgescu-Roegen・鷲田豊明等の指摘した「資源散逸条件」を適切に考慮する事が重要である。特に、鷲田が線形模型について導出した条件を、廃棄物を含有資源量ではなくて総量で計測した場合について導出し、鷲田模型との理論的関連を明確にした。研究成果の発表An Interindustry Approach to Analyzing Economic and Environmental Effects of the Recycling of Waste, Ecological Economics, Elsevier,受理済み

  • ミクロパネルデータを用いた生産関数の形状と生産性変動に関する研究

    1996年  

     概要を見る

     筆者が1990年に発表した一般型尾崎費用関数を、これが伸縮性を失うことなく、要素価格について大局的に凹性を満たすように改良した、一般型尾崎-McFadden費用関数を作成した。この関数の実証的挙動を分析するために、紙・パルプ産業の企業パネルデータについて推定した。 推定の結果、大局的な凹性は自動的に満たされていた。さらに、スルツキー行列の対称性も棄却されなかった。トランスログ関数を、同じデータについて推定し、挙動を比較した。トランスログ関数を用いると、標本の10%ほどに於いて凹性が満たされなかった。これに対して、非相似性は、一般型尾崎-McFadden、トランスログのどちらを用いても棄却できなかった。 一般型尾崎-McFaddenが、トランスログよりも経済学的に望ましい結果を示しうる例を得た。更に、非相似性が頑健であり関数型に依存しない事を確認した。

  • ミクロ動学モデルによる生産関数非相似性の研究

    1995年  

     概要を見る

    伸縮的でありながら大局的な凹性を持つ一般尾崎 McFadden 費用関数 (GOM) を導出し,これを我が国紙/紙パルプ製造業の企業パネルデータに応用した。この費用関数型はNakamura (1990) による一般尾崎費用関数(GO) に大局的な凹性を付加したものであり,Komiya (1962), Ozaki (1969) 等によって考慮された非線形Leonief固定係数モデルを特殊例として含んでいる。さらに本研究では,パネルデータを用いることから,通常の時間趨勢の代わりにBaltagi-Griffin (1987) による一般的な技術変化指標を用いた。 推定の結果GOMモデルは大局的な凹性を自動的に満たした。更に,スルーツキー行列の対称性も棄却されない。結局,推定されたGOMモデルは積分可能条件を満たしている。比較のためにトランスログモデルも推定したが,観察点の約8パーセントにおいて凹性が満たされていない,と言う結果を得た。GOMモデルの正則域の方がトランスログモデルのそれよりも標本をよく内包すると考えられる。 しかしながら,GOMとトランスログモデルのどちらにおいても相似性は強く棄却された。特に,資本労働比率が生産量の増加とともに増加することが見いだされた。要素制約性に関しては統一的な結果は得られなかった。

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