EXECUTIVE SUMMARY... 3 CHAPTER 1: INTRODUCTION... 7 CHAPTER 2: GOAL, SCOPE, TERMINOLOGY AND DEFINITIONS... 8

Transcription

1 World Steel Life Cycle Inventory Methodology Report 1999/2000 I NTERNATIONAL I RON AND S TEEL I NSTITUTE C OMMITTEE ON E NVIRONMENTAL AFFAIRS Brussels, October 2002

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3 CONTENTS EXECUTIVE SUMMARY... 3 CHAPTER 1: INTRODUCTION... 7 CHAPTER 2: GOAL, SCOPE, TERMINOLOGY AND DEFINITIONS GOAL SCOPE Function and functional unit System boundaries Process Routes, Technology Coverage ROUTE/SITE/MODULE DATA CATEGORIES Waste/Recovered Material Air and Water Emissions Energy Reminders CHAPTER 3: DATA QUALITY, GEOGRAPHICAL COVERAGE AND CRITICAL REVIEW DATA SOURCES AND STEEL PLANT QUESTIONNAIRES Site Data Upstream Data DATA QUALITY CUT-OFF RULES DATA PRECISION, COMPLETENESS, AND CONSISTENCY CRITICAL REVIEW GEOGRAPHICAL COVERAGE AND AVERAGING CHAPTER 4: METHODOLOGICAL ASSUMPTIONS AND ALLOCATION PRINCIPLES UPSTREAM INVENTORIES Ferrous Scraps Electricity Iron ore and coal Intermediate products from external supply Other raw materials External transportation ALLOCATION Partitioning Multi-function Systems EAF Route Conclusion

4 4.3 WASTE TREATMENT ALLOCATIONS FLARES PACKAGING MATERIALS AND INTERNAL TRANSPORTATION CHAPTER 5: INTEPRETATION CONTRIBUTION ANALYSIS CONTRIBUTION ANALYSIS BY ARTICLES Carbon Dioxide (CO 2 ) Nitrogen Oxides (NO X ) Total Particulates Sulphur Oxides (SO X ) (w) Suspended Matter Total Waste Total Primary Energy Sensitivity Analysis System Expansion vs. No Allocation Coal and Electricity CHAPTER 6: DATA SHEETS EXPLANATIONS DATES STATISTICS LCI FLOWS/ARTICLES CHAPTER 7: CONCLUSIONS ACRONYMS AND ABBREVIATIONS LIST OF TABLES LIST OF FIGURES APPENDICES

5 EXECUTIVE SUMMARY IISI Life Cycle Inventory Study for Steel Industry Products Introduction Selecting the most appropriate materials for any application depends on the consideration of a range of technical and economic factors including, for example, functionality, durability and cost. A further and increasingly important factor for material specifiers in a world where sustainable development is a key issue is the associated environmental performance of material applications both from a manufacturing and product performance perspective. Among the tools available to evaluate environmental performance, Life Cycle Assessment (LCA) provides a holistic approach to evaluate environmental performance by considering the potential impacts from all stages of manufacture, product use and end-of-life stages, sometimes called the cradle-to-grave approach. LCA generally comprises four major components: - Goal and scope definition; - Life Cycle Inventory - data collection and calculation of an inventory of materials, energy and emissions related to the system being studied; - Life Cycle Impact Assessment - analysis of data to evaluate contributions to various environmental impact categories; and - Interpretation - where data are analysed in the context of the methodology, scope and study goals and where the quality of any study conclusions is assessed. A life cycle inventory (LCI) study has been carried out by the International Iron and Steel Institute (IISI) to quantify resources use, energy and environmental emissions associated with the processing of fourteen steel industry products from the extraction of raw materials in the ground through to the steel factory gate. The study was carried for data by the IISI with technical liaison and co-ordination through an IISI LCA Forum, based on data collated within IISI member companies. LCI data were calculated for products derived via the blast furnace/basic oxygen furnace route (based on iron ore and steel scrap) and the electric arc furnace route (mainly based on steel scrap). Downstream processing into manufactured products, their use, end of life and scrap recovery processes have not been included in the inventory, making this a cradle-to-gate study. The boundaries of the study can be extended to include downstream activities particularly in collaboration with customers who are applying LCA s to their product systems. Goals The primary goals of the study were to develop a unified and rigorous LCI methodology for steel products worldwide in accordance with the IISI Policy Statement on LCA and related ISO14040 set of standards to provide reliable data to meet requests from customers and external studies. Further goals were to promote the environmental credentials of steel and to develop steel industry expertise in the subject. Scope The fourteen products included in the study are the main finished products of the steel industry. They include hot rolled coil (with and without pickling), cold rolled coil (with and without finishing), hot dip and electrically galvanised sheet, painted sheet, tinplate and tin-free sheet, tubes, sections, plate, rebar/wire rod, and engineering steels. The products are of general relevance to a wide range of downstream applications including those in the construction, automotive and packaging sectors. 3

6 Stainless steel products were not included but a separate study has is being carried out to provide data on these; the results of the global study will be available in the near future, whereas the European study is available now. In total, 50 sites operated by 28 companies, including 34 blast furnace operations, 13 electric arc furnace operations, and 3 direct reduction operations participated in the study. The companies contributing data to the LCI study account for 39.7% of global crude steel production outside of the former USSR and China. Companies in Europe, and Far East Asia were well represented and a typical range of operating configurations included, North America is included in the global averages. This level of coverage maintains the IISI LCI study one the most representative LCI studies ever carried out for a material and this provides a sound basis for LCA studies relating to steel. Methodology The quality and relevance of LCA/LCI results, and the extent to which they can be applied and interpreted, depends critically upon the methodology used. It is therefore important that methodology is transparent and well documented. ISO standards have been developed to provide guidance on methodological choices and to set down rules for transparency and reporting. To date, the relevant ISO standards have been published are: 4 i. ISO 14040, which sets down the Principles and Framework of LCA, ii. ISO 14041, on Goal and Scope Definition and Inventory Analysis. iii. ISO 14042, on Life Cycle Impact Assessment, and iv. ISO 14043, on Life Cycle Interpretation. The goal of the IISI project was to produce LCI s with sufficient scope to facilitate the range of emerging impact assessment methods in future studies. The IISI LCI study has been fully reported in accordance with ISO and ISO and has undergone critical review from an independent Critical Review Panel (CRP) of LCA specialists. This approach improved the integrity of the study and can help guide methodology. The full CRP Report is included in the report. The main CRP conclusions were: The International Iron and Steel Institute has done a commendable job in the planning, design and implementation of the IISI Worldwide LCI Database for Steel Industry Products. This database will be a valuable resource for LCA studies involving steel products. We have found this LCI study well constructed and adhering to the requirements of the International Standards ISO 14040, and relating to Life Cycle Inventory Analysis (LCI), with a few reservations: - We missed a listing of data quality requirements as specified in ISO 14040, clause , in spite of data quality generally being well documented, especially for the core steel manufacturing processes. - We did not find the requirement in ISO 14041, clause to be fulfilled with respect to excluded upstream processes and the treatment of data gaps in the upstream processes. This also implies that we found the sensitivity analyses inadequate to assess and describe the potential effects of these exclusions on the outcome of the study, as required in ISO 14041, clause The interpretation section of the draft report did not conform to ISO 14043, especially with respect to interpreting the results in relation to the goal and scope (applications) of the study. Our critical remarks should be seen as suggestions for improvement and does not challenge our overall impression of a very thorough and dedicated study, which contributes significantly to the state-of-the art of practical LCI studies.

7 We wish to express our gratitude to IISI for providing the opportunity to review this work in detail, and for the constructive atmosphere in which our comments have been received. Critical Review Report, 25 June IISI welcomes the comments made by the critical review panel, and is in full agreement with the majority of the critical review panel report. IISI believes that the critical review process was an essential step in the Worldwide LCI for steel products and considers that the report adds value to the methodology report. In response to the CRP s report, the IISI accepts that due to the large number of upstream modules in the model, not all will have the same allocation procedure and data quality. The standards required by the database owner for the software model are high, allocation procedure is detailed in the information facility of each module used, and is subsequently listed in full in Appendix 6 of the IISI methodology report. IISI accepts that with respect to ISO14041, clause , particularly precision and uncertainty, the information is limited due to the fewer datasets available for input to the study, but otherwise we consider this to be adequate for the purpose of the study, and upstream data (mainly from DEAM) quality information is available. Upstream data sourced directly by IISI (e.g. iron ore) is consistent with the data quality of the primary data for steel processes. In view of the comments made on the completeness of the interpretation, the IISI believes that the whole report contributes to the interpretation phase, and that the report has been enhanced to cover aspects of interpretation covered in ISO Overall, we believe that the results have been analysed, and the limitations of the study explained, to provide the transparency and confidence that these data are adequate for LCA s using steel. Results The LCI results provide cradle to gate (of the steel factory gate) data on all the major raw materials, energy usage, air and water emissions, and wastes for each of the fourteen steel products included in the study. In total about 450 data categories (flows) have been quantified but for simplification 43 major flow categories are presented in summary tables for communication to third parties. These flows include average values for air and water emissions that were fully accounted in the data collection exercise. Other emissions data were included but site measurements and/or upstream data quality on these emissions were thought to be insufficient to generate reliable averages. Both worldwide and regional averages (Western Europe, Far East Asia and Rest of the World) are available provided that a minimum of three sites contributed data for that product. Additional information includes the number of sites contributing to the average and minimum, maximum and variance for each LCI flow. These data indicate the variation across individual sites and can be used to facilitate sensitivity analyses. The LCI results aggregate the contributions of between 150 and 250 process units depending on the product. IISI intends to pursue continuous improvement of the data quality with time. This will include further updates of the data and expanding the range of reliable data categories as measurement techniques become more widespread. Further efforts will also be made to acquire data for upstream operations directly from suppliers, making the data more regionally relevant and reducing the dependence of results upon generic databases. Availability of Data LCI data can be obtained via the online request facility on the IISI website, which in turn informs the relevant LCA Managers within member companies and organisations across the world. Contact names can be obtained from IISI. The normal procedure is to complete a questionnaire describing the intended application of the data and to discuss this with the LCA Manager. This will help to ensure that the IISI methodology and results can be applied appropriately and will be compatible with the goals of the study. 5

8 Conclusions The IISI LCI study has generated one of the largest, most rigorous and representative databases of any material. The results can be used reliably to assist decision-making and for evaluating the performance of steel products in the context of sustainable development. The results also provide the opportunity for steel companies to benchmark and evaluate improvement measures to their processes and product systems. Steel industry expertise has been enhanced by involvement in the study and the industry is now better equipped to provide technical support to customers and users of steel on LCA issues. The program of the IISI LCA Forum (launched after the first study) to keep the database up to date and further enhance the methodology and understanding of the study has been successful in raising the profile of LCA within the steel industry, and to its customers. Recommendations for improvement concerning both the documentation and the data will be highly welcome. For LCA to be used as reliable tool for decision making high quality data, sound methodology and transparent reporting are essential. This study is a major step towards enhancement of these standards and the steel industry intends to continue and encourage this trend in its future programme of work. For further information, please contact: LCA Manager International Iron and Steel Institute Rue Colonel Bourg 120, 1140 Brussels, Belgium Tel. (direct): +32 (0) Fax. +32 (0) lca@iisi.be See also: 6

9 CHAPTER 1: INTRODUCTION This report presents a summary of the second Worldwide IISI LCI Study. It provides an explanation of the methodology, results and interpretation of the LCI data for steel products. The study was originally carried out for 1994/1995 data and as part of the IISI ongoing commitment to improving data quality has now been updated for 1999/2000 data. The main goal of the study was to provide high quality LCI data for steel products on a global and regional basis. It is believed that other data sets on steel have been derived with limited accuracy or representation and/or contain out of date information. The IISI data contains data on process operation in 1999/2000 collected at individual sites with a universally applied methodology for data collection and LCI calculation. Whilst the report aims to describe the details of the LCI methodology, further details on the steel industry processes are available from other publications (available via the IISI website for example, the IISI/UNEP report Steel Industry and the Environment, Technical and Management Issues, 1997, and IISI Committee on Technology reports Energy Use in the Steel Industry which provides good technical references and specific information on environmental issues. Although this report features a comprehensive level of detail, it is intended to serve as a basis of dialogue between steel industry representatives and third parties using the data. Recommendations of improvement concerning both the documentation and the LCI data are highly welcomed. They will be considered as the IISI LCI database is improved in future. The IISI LCI study has been undertaken in accordance with the ISO14040 set of standards, and in this respect has undergone critical review from an independent panel of specialists, the critical review panel (CRP), to comment on the methodology and reporting of the study. This approach improved the integrity of the study and helps establish transparency. The final CRP report is included in this report. 7

10 CHAPTER 2: GOAL, SCOPE, TERMINOLOGY AND DEFINITIONS 2.1 Goal LCA continues to be a topic of growing interest to the steel industry, as well as other industries, and independent LCA studies have been conducted by several steel companies and regional steel associations, mostly relating to packaging, construction and automotive applications. However, as these studies were different in purpose, system boundary and methodology, in 1996 the Board of Directors of IISI initiated the original global LCI on Steel Industry Products in order to avoid inconsistency and duplicated effort. The update for 1999/2000 data follows the same criteria, The goals of the project were to: - To develop the common worldwide methodology for cradle-to-gate steel product Life Cycle Inventories (LCIs) from the original study for the successful update study. - Produce worldwide LCI data for steel industry products. - Support communication with industry stakeholders. - Assist industry benchmarking and environmental improvement programmes. This aimed to subsequently form the basis for full LCAs, including life cycle impact assessment, across broader boundaries and complete product life cycles. The methodology was defined in compliance with the IISI Policy Statement on LCA and with ISO standards relating to LCA as described in the following sections. 2.2 Scope Function and functional unit Within the scope of this study, the system function is the production of a steel product at the factory gate. Further functions relating to the generation of by-products from the steel production system have been eliminated using the allocation procedure recommended in ISO as documented in Section 4.2. The functional unit, which enables the system inputs/outputs to be quantified and normalised, is one kilogram of steel product at the factory gate. Fourteen steel products (see Table 2-1) were included in the study. The detailed specifications of each steel product, such as size range, gauge and coating thickness, vary from site to site and are a function of the technology, equipment and product ranges at the sites involved. The range of specifications within a product category will to some extent influence the regional and global LCI ranges. A more detailed correlation between the LCI results and product specifications is the subject of ongoing work, but is outside the scope of this study. In particular, Rebar & wire rod (referred to as bars ) were grouped together to rationalise the number of spreadsheets and to help accumulate data for products with similar processes. 8

11 Product Category Manufacturing route List of products Long products Blast furnace route and Electric arc furnace route Sections Rebar/ Wire Rod Engineering Steel Flat products Blast furnace route Plate Hot Rolled Coil Cold Rolled Coil Pickled Hot Rolled Coil Finished Cold Rolled Coil Electrogalvanised Hot-dip Galvanised Tin-free Steel Tinplated Products Organic Coated Flats Welded Pipes Table 2-1: List of Products covered by the Study The study focused on carbon and low alloy steels (with alloy content lower than 2 %). Notably stainless steels (with at least 12% chromium) were outside the study scope, but again form the basis of another study System boundaries The study is a <cradle-to-gate> LCI study. That is, it covers all of the production steps from raw materials <in the earth> (i.e. the cradle) to finished products ready to be shipped from the steelworks (i.e. the gate). It does not include the manufacture of downstream products, their use, end of life and scrap recovery schemes. System Raw material and energy production (including extraction) Site boundaries Transportation Steelworks Steel products Natural resources from earth Consumables production Scrap Recovery processes Non allocated By-products Merchant scrap, other steelworks, etc. minus Saved external operations By-products Equivalent By-product functions Emissions to earth Figure 2-1: System Overview 9

12 As shown in Figure 2-1, the steel product manufacturing system encompasses the activities of the steel sites and all major upstream processes, including the production and transportation of raw materials, energy sources and consumables used on the steelworks. Certain upstream stages, which have a negligible contribution to the resulting LCI, were excluded (see section 3.3). In addition the recovery and use of steel industry by-products outside of the steelworks are taken into account using in most cases the method of system expansion as described in Section 4.2. Externally supplied scraps are sourced from merchants, other factories and municipal facilities. As indicated in Figure 2-1, no upstream burdens from scrap recovery or treatment are included except transport from the latter sources. No allocation procedure for recycling situation was applied to the use of scraps but the net input is quantified in the data sheets to accommodate the extension of system boundaries in future studies for individual products. The issue of scrap allocation is further discussed in Appendix Process Routes, Technology Coverage Steel is produced predominantly by two process routes; the blast furnace route and the electric arc furnace route (the BF and EAF routes respectively). The BF route is primary ore based with up to 25 % scrap input and the steelmaking stage of this route is carried out using the basic oxygen furnace. The EAF route is predominantly a 100% scrap based steelmaking process. Both routes continuously cast products that feed into hot and cold rolling processes. Cold rolling together with coating and finishing processes for flat products are termed here the cold rolling route. Flat products are produced predominantly from the BF route whilst long products are produced from both the EAF and BF routes. Table 2-1 indicates that no flat products from the EAF route were included in the study; however, this is a growth area (e.g., North America), and as such was included in the scope of the study, however these data were not included in the averages due to the low number of sites. Other emerging process technologies include direct reduction of ores that replace the BF route (such as Midrex), these technologies represent a small, but growing contribution to world production, and for this reason are also included in the scope of the study, but no averages were calculated due to the low number of sites. Other steel making technologies such as the open-hearth process (being around 4% of world steel production in 1999) and ingot cast steel products (being less than 16% of world steel production in 1999) were not included. Open-hearth steelmaking and ingot casting technologies are declining for both economic and environmental reasons and tend to be used only in the former eastern block and China. 2.3 Route/Site/Module Terminology has been developed for the various system components as follows. Route refers to the full cradle to gate system including upstream supplies, transport and by product credits. Site refers to the steelworks boundaries. Modules are the component unit processes within the site and the route. A Module corresponds either to one of the main process stages and its associated ancillary workshops (e.g. coke oven battery, coke gas scrubbing and by-products plant) or to a common utility to the site (e.g. a power plant producing electricity and steam). The latter formed the basis for the site questionnaire design that identified specific inputs/outputs for each process stage. A representation of the Basic Oxygen Furnace module is given in Appendix 2. Similar flow diagrams were developed for each site module and used in the questionnaire manual. The modular structure at the site level is required for the LCA calculation because most sites import and/or export intermediate materials (such as coke, hot metal, slabs, etc.). It also 10

13 facilitates data/error analysis and can assist with the potential application of results for benchmarking and environmental improvement. Overall, the LCI results aggregate the contributions of between 150 and 250 process units depending on the product. Information on the contributions can be made available on request. Primary data was collected for 20 separate steelmaking process steps (Table shows the break down), plus water intake, effluents, stockpile emissions, energy, transport, and Fe-C content of flows. Process Stage Number of Processes Process Stage Number of Processes Coke making 28 Engineering Steels 6 Sinter making 25 Seamless/Welded Pipe 5 Blast Furnace 29 Pickling Plant 23 Direct Reduced Iron 2 Cold Rolling Mill 26 Basic Oxygen Furnace 29 Annealing & Tempering Mill 26 Electric Arc Furnace 14 Electrogalvanising 11 Hot Strip Mill 24 Hot-dip Galvanising 19 Section Mill 10 Tin-Free Mill (ECCS) 6 Heavy Plate Mill 11 Tinplate Mill 10 Rebar 10 Organic Coating Line 11 Total Processes 325 Table 2.3-1: Number of process stages represented in the study The steel product manufacturing flow diagrams via Blast Furnace Route, Cold Rolling Route and Electric Arc Furnace Route are shown in Appendix Data Categories The LCI study set out to include all significant inputs and outputs from the steel production route so that any future studies could consider a range of impact categories. Thus all major materials and energy inputs, air and water emissions and solid wastes were included. Notably emissions to soil, which can relate to contaminated land issues, were not included. The methodological aspects for key data categories are discussed below Waste/Recovered Material Material disposed of in landfills, both internal and external to the steel works, and incinerated materials have been classified as waste. For allocation and material balancing purposes materials recovered within the site were identified in the questionnaire and treated in calculation as negative flow inputs at the module where they arise and as positive inputs to the modules where they are recovered/consumed. This rule included the treatment of recovered internal scrap. With the exception of scrap and process gases, the net balance of these internally recycled materials is generally small. 11

14 Finally, materials exported from the site for external applications have been classified as byproducts (also terms by product or recovered matter ). Some materials are partly waste and partly by-products. In such cases, the ratio between byproducts and waste was identified in the questionnaire for site data collection, and a summary can be found in section 6.3. Allocation procedures were applied only to the by-products Air and Water Emissions A list of all known air and water emissions was defined and drawn up for each process stage and included in the site questionnaires for data collection. Because techniques of measurement are more advanced for some sites than others, the combined list of known emissions was more extensive than the typical emission monitoring data collected routinely at any one site. Thus because of limited available data, certain emissions had too few data sets to provide reliable average data. To distinguish between emissions that are known to exist and those which have reliable data for global averaging a set of accounted emissions has been defined for both air and water. These include emissions for which most sites have data and for which calculations, based on reliable site averages, could be used to insert values in the few questionnaires where data were missing. The list in Table has been developed for this study to include the significant emissions for global warming, air acidification, eutrophication indices, a more comprehensive selection of heavy metals, and emissions of minor interest for LCA studies. Further explanation of the air and water articles can be found in section 6.3. Non-accounted emissions were those with too few data sets to apply reliable averages to sites with missing data, but which comprise of important emission categories. As measurement techniques become wider spread, reliable averages can be derived and applied in future. Another factor was that upstream data modules used in the LCI calculation did not necessarily contain all the air emission flows included in the steel plant questionnaires. Hence, even though steel site data may be complete, the upstream data may not take full account of all the air emission categories. A list of non-accounted emissions with minimum and maximum values can be obtained on request but for the reasons given the ranges are not considered reliable. Regarding water emissions specifically, when recorded in the questionnaires, the pollutant amounts in the intake were subtracted from the pollutant amounts in the discharged wastewater because they are not attributable to the steelmaking processes. For some sites located downstream of urban and industrial areas, the outflow water is purer than the intake. However, there are many gaps for this category of data for which it is not possible to calculate an estimate. Therefore, the values of waterborne emissions are potentially overestimated in terms of net emissions. 12

15 Accounted Emission Original Study 1995 Updated Study Greenhouse Gases CO 2 CO 2, CH 4, N 2 O, HFC s, PFC s, SF 6 Air Acidification Gases Organic Emissions NO X, SO X as SO 2 NO X, SO X as SO 2, HCl, H 2 S Dioxins VOC s (excluding methane) Metals Cd, Cr, Pb, Zn Others CO, Particulates (Total) CO, Particulates (Total) Metals Cr, Fe, Zn, Pb, Ni Cr, Fe, Zn, Pb, Ni, Cd Water Others Cl-, F-, Phenols, CN-, N (except ammonia), P matter, Phosphates, COD, S2-, NH4+ (as N), Suspended Matter (unspecified) N (except ammonia), P compounds, Ammonia, COD, and Suspended Matter. Table 2.4-1: List of accounted air and water emissions Energy Reminders The primary components of a Life Cycle Inventory are the material inputs and outputs that are taken from or are emitted to earth. Certain material inputs, particularly fuels such as coal, oil etc constitutes energy as well as mass inputs, which can be calculated based on calorific value. Within the LCI data sheets, these accumulated energy values are indicated in a separate section in order to facilitate energy analysis and to remind analysts that these values are derived from material inputs and are not in addition to them. The section is referred to as Energy Reminders. Energy reminders can be considered to be outside the normal scope of an LCI; however, IISI included these categories to assist with data verification and interpretation purposes. Within Energy Reminders the calculated energy indicators have been based on net (low) calorific values and included the following: - Total primary energy: this is the sum of all energy sources which are drawn directly from the earth, such as natural gas, oil, coal, biomass or hydropower energy. The total primary energy contains further categories namely non-renewable and renewable energy, and fuel and feedstock energy. These are described below: - Non-renewable energy: includes all fossil and mineral primary energy sources, such as natural gas, oil, coal and nuclear energy. - Renewable energy: includes all other primary energy sources, such as hydropower and biomass. - Fuel energy: is that part of primary energy entering the system which is consumed. 13

16 - Feedstock energy: is that part of the primary energy entering the system which is not consumed and/or is available as fuel energy and for use outside the system boundary. In the case of steelmaking, this includes the calorific value of energy of the outputs (such as that contained in products, recovered materials and waste) as well as fuel losses. In practice, feedstock energy from waste and fuel losses were omitted. The sum of fuel and feedstock energy, as well as the sum of renewable and non-renewable energy always equates to the total primary energy. Practically, the steel product feedstock energy is low compared to primary energy values since the calorific value of steel was assumed zero and the by-products feedstock energies were accounted for by allocation procedures relating these to primary energy. The definition of fuel energy within the LCI Study covers all the energy that is spent for process purposes, either to produce heat, mechanical energy or to enable endothermic chemical reactions to take place. Thus, that proportion of the coke and blast furnace injectants, such as natural gas, coal and oil, which are used as reducing agent are included in fuel energy. Within the study, the primary energy calculation is based on the following parameters: - Net caloric values for fossil, mineral and biomass materials, - Gravitational energy for hydropower: 1.11 MJ of gravity energy yields 1 MJ of electricity, - Burn-up rate for uranium ore: g of uranium ore, equivalent to 3.19 MJ of primary energy, yields 1 MJ of electricity. 14

17 CHAPTER 3: DATA QUALITY, GEOGRAPHICAL COVERAGE AND CRITICAL REVIEW 3.1 Data Sources and Steel Plant Questionnaires Site Data Site data were collected on custom designed and developed questionnaires that were formulated through meetings between Ecobilan and IISI. Questionnaires were organised into process stages as defined in Appendix 1 and ancillary utilities such as power plants, compressors, common effluent and waste treatment plants, each of which contained lists of material and energy inputs, air and water emissions, wastes, products and by-products and recovered material categories. A pre-screening exercise took place, involving the ranges from the original study, to obtain typical data values in order that the site questionnaires could include algorithms to flag up out-oftypical-range data. A training manual was developed to describe the procedures for entering site data in accordance with the methodological rules. Questionnaires also contained an iron and carbon balance facility for further verification at the site level. Data sources were defined in three categories F, L and O to be entered in the questionnaires. These were: - Factory: Site-specific measured or calculated data. - Literature: value based on literature information. - Other: data obtained from other site sources e.g. data extrapolated from other steel sites. Each of these data points is then categorised in terms of data quality, by type (Measured, Calculated, an Average, Estimated, or Unknown), and by date ( , , , <1989) and scored respectively. Further explanation of data quality is detailed in section 3.2. Statistics on these data sources and scoring are shown in Appendix Upstream Data Data for processes outside of the steel industry, e.g. upstream and by-product recovery operations were generally obtained from professional LCI databases and literature sources. The quality and transparency of methods to derive these data are less well defined than the steel industry specific data in terms of reliability, geographical relevance, methodology and completeness. In order to avoid potential data quality problems arising from this, the IISI acquired data for those upstream processes that were judged to have a significant contribution to the global LCI results. Data were collected directly from representative sites for iron ore mining, pellet making, limestone quarrying, lime production and sea transport for the original project, and iron ore mining, pelletising (forming additional LCI s), coal mining, and other steelmaking additions for the updated project. Appendix 4 summarises the list of upstream modules that have been used. The main assumptions concerning those upstream models are described in section

18 3.2 Data Quality The data collection methodology featured extensive data quality requirements, in order that the goal of the study could be satisfied in a quantitative manner, and in accordance with the ISO standards. Five data quality categories were specified for each data entry in the steel plant questionnaires as follows: - Measured: flow where values have obtained from continuous or spot measurements on site. For instance, continuous measurements may include the total electricity consumed, which is readily available from electricity meters, or the coal consumption, measured at the weighbridge or using some other form of stock accounting. Spot measurements may include VOC emissions measured quarterly, over the period of a few hours, from which the annual value has been calculated. - Calculated: the flow value has been calculated using some form of empirical ratio (e.g. emission factors, etc.), mass balance or other indirect method. For instance, SO X emissions may have been measured over a period of several years and an emission factor determined and used for the subsequent measurements or CO 2 emissions may be calculated based on a carbon balance for a process. - Averaged: flow value was obtained from an average such as the global averages used as part of the IISI LCI study, or averages from internal information sources on site. - Estimated: the estimated flow value has been established based on approximations. For instance, the transportation distance of a raw material may be estimated because of a lack of better information. - Unknown: This data type is only available for data from literature sources where there is insufficient information to classify the data into the previous types. Data collection related to one-year operation and questionnaires indicated the reference year specific to each data point. The majority of data was derived from the most recent records, primarily covering 1998 to 2000, and in some cases the original data was considered valid for inclusion in the update, and therefore the date indication remained the same. Statistics on data types and age are shown in Appendix Cut-off Rules Criteria were set out in the original study for the recording of material flows and to avoid the need to pursue trivial inputs to the system. These are outlined below: 1. All non-mass inputs to the process stages were recorded, including energy carriers (heating fuels, electricity, steam, compressed air) and water (recorded by volume). 2. At least 99.9% of material inputs to each process stage were included. 3. Wastes representing less than one percent of total waste tonnage for given process stages were not recorded unless treated outside of the site. Criterion 2 was attainable because site input tonnages are weighed by relatively few inputs such as iron ore, pellets, limestone, scrap, dolomite, olivine, serpentine, metallic additions, refractories, coke, sinter, hot metal, and intermediate steel products which account for >99.9% of material inputs to each process stage. 16

19 Following the contribution analysis carried out on the original study, the list of site inputs was simplified for the update. All site inputs, which cumulated contributions, represent less than 2% of the data categories in the data sheets were excluded from the data collection. The criteria for inclusion/exclusion of upstream environmental burden are presented in section Data Precision, Completeness, and Consistency All questionnaires returned from the sites were checked individually by IISI. Suspected out of range data and important missing information were detected both automatically, using a check programme, and manually, following visual inspection of the data. Where data was missing or suspected to be erroneous the site was contacted until all necessary data was received. When completed, the questionnaires were downloaded electronically into TEAM TM using an interface programme specifically developed to avoid typing and miscalculation (e.g. unit conversion) errors. This procedure ensured that a comprehensive and accurate data set was received from each site and that these data were accurately transferred into TEAM TM prior to LCI calculation. After carrying out the initial LCI calculation, the results were distributed to the sites in order that extreme values, revealed by the statistical analyses, could be checked and verified or corrected and the energy balance could be checked using the energy reminders described above. Based on the experience from the original study, and the interaction with the sites with the results, the LCI became ever more accurate and robust. 3.5 Critical Review The methodology, results, and interpretation of the LCI study for 2000 were subjected to a critical review, to ensure that the project was consistent with the ISO14040 standards. The critical review panel for the updated study were Dr. Weidema (2. 0 LCA Consultants, Denmark), Dr. Keoleian (University of Michigan, US), and Dr. Inaba (National Institute of Advanced Science & Technology, Japan). The full critical review panel report is included in Appendix 10. Study critical review The conclusion of the critical review panel report was that The International Iron and Steel Institute have done a commendable job in the planning, design and implementation of the IISI Worldwide LCI Database for Steel Industry Products. This database will be a valuable resource for LCA studies involving steel products. We have found this LCI study well constructed and adhering to the requirements of the International Standards ISO 14040, and relating to Life Cycle Inventory Analysis (LCI), with a few reservations: We missed a listing of data quality requirements as specified in ISO 14040, clause , in spite of data quality generally being well documented, especially for the core steel manufacturing processes. We did not find the requirement in ISO 14041, clause to be fulfilled with respect to excluded upstream processes and the treatment of data gaps in the upstream processes. This also implies that we found the sensitivity analyses inadequate to assess and describe the potential effects of these exclusions on the outcome of the study, as required in ISO 14041, clause The interpretation section of the draft report did not conform to ISO 14043, especially with respect to interpreting the results in relation to the goal and scope (applications) of the study. Our critical remarks should be seen as suggestions for improvement and does not challenge our overall impression of a very thorough and dedicated study, which contributes significantly to the state-of-the art of practical LCI studies. 17

20 Critical Review - IISI Response IISI welcomes the comments made by the critical review panel, and is in full agreement with the majority of the critical review panel report. IISI believes that the critical review process was an essential step in the Worldwide LCI for steel products and considers that the report adds value to the methodology report. In the light of the critical review comments, the following opportunity is taken to address some of the issues, on a case-by-case basis (the full response is found in Appendix 10), in the context of the current IISI position, and for the future use of the study. In view of the comments made on upstream data quality, IISI, as part of its continuous improvement commitment, will work to obtain and use better upstream data for the worldwide LCI study for steel products. IISI accepts that due to the large number of upstream modules in the model, not all will have the same allocation procedure and data quality. The standards required by the database owner for the software model are high, allocation procedure is detailed in the information facility of each module used, and is subsequently listed in full in Appendix 6 of the IISI methodology report. IISI accepts that with respect to ISO14041, clause , particularly precision and uncertainty, the information is limited due to the fewer datasets available for input to the study, but otherwise we consider this to be adequate for the purpose of the study, and upstream data (mainly from DEAM) data quality information is available. Upstream data sourced directly by IISI (e.g. iron ore) is consistent with the data quality of the primary data for steel processes. As described above, primary data was pursued for important upstream processes such as coal, lime, and cement but only limited response was received, therefore we agree that the quality of the upstream data could be improved and will be an area for continuous improvement. IISI believes that these data are sufficiently transparent and accurate to justify their inclusion in the study, and to expand the database in the future. In view of the comments made on the completeness of the interpretation, the IISI believes that the whole report contributes to the interpretation phase, and that the report has been enhanced to cover aspects of interpretation covered in ISO Overall, we believe that the results have been analysed, and the limitations of the study explained, to provide the transparency and confidence that these data are adequate for LCA s using steel. 3.6 Geographical Coverage and Averaging Geographic Coverage (Original study figures in brackets) The companies participating in the study produce about 39.7% (38.9%) of global steel production excluding the former USSR and China and the contributing sites are among the largest of the principal producer countries, representing 7 out of the 10 top steel making companies in the world. At regional level the participating companies produce 60% (44%) of European, 72% (69%) of Far East Asian and 13% (24%) of North American steels. The list of participating companies is shown in Appendix (55) sites located in 20 (17) countries participated in the study (see Table 3.6-1). The sites represented account for 16% (17%) of the total worldwide crude steel production and 21% (22%) when excluding former USSR countries and mainland China. The total production of the participating countries exceeds 53% (55%) of the world total crude steel production. The highest level of representation is for Western Europe (EU15) with 36% (45%) of the EU15 crude steel production followed by Far East Asia with 34% (34%). 18

21 Blast furnace/rolling and coating/ Integrated sites Electric arc furnace sites Western Europe EU15 Far East Asia Rest Of The World (Including N. America) 20 (29) 8 (7) 6 (2) 8 (7) 3 (3) 2 (1) Direct Reduction 0 (0) 1 (0) 2 (0) Table 3.6-1: Number of Contributing Sites per Region (Numbers in brackets indicate the original study). Western Europe EU15 Far East Asia World Total Crude Steel Production (IISI data) (Million metric ton) 163 (156) 166 (138) 847 (752) excl. former USSR and China: 630 (578) Crude steel production of participating sites (Million metric ton) 58.0 or 36% (63.1or 41%) 55.6 or 34% (46.4 or 34 %) 132 (126) Table 3.6-2: Part of Total Crude Steel Production covered by the Study (Numbers in brackets indicate 1995 data). The groups defined for reporting of regional statistics include: Western Europe (EU15), Far-east Asia (Japan, Korea, and Taiwan), and Rest-of-the-World (includes Canada, Czech Republic, Mexico, Slovak Republic, South Africa, Turkey, and US). This group includes the North American sites, as there were too few to calculate a separate average. Regional LCI averages are considered as particularly appropriate since (carbon) steel products are traded mainly at the regional level. Although the study reached a remarkable level of representation, the sampling of sites could be expanded for specific products such as seamless and welded pipe, and for process steps, such as DRI. Averaging Averages have been calculated straight (without weighting the contribution according to production tonnage) and vertically (i.e. LCI s are calculated for each site, and the resulting values averaged across the contributing sites). It was considered that weighted average according to production tonnage was not appropriate since not all steel plants were represented. Furthermore, straight averages facilitate interpretation and benchmarking exercises. In general, it is believed that the sensitivity of the results to the averaging options is low, especially compared to other sources of uncertainty such as the upstream models. 19

22 Some care is needed in interpreting the data differences associated with products from subsequent and parallel process stages because the sample size of sites become fewer as the products become more complex. Thus averages can be derived from different sample sets. Horizontal averaging was enabled in the event that the sample of sites for a product was not representative enough, however all products studied in the update allowed averages to be calculated. 20

23 CHAPTER 4: METHODOLOGICAL ASSUMPTIONS AND ALLOCATION PRINCIPLES The following sections explain the basis of calculation of the LCI s particularly the allocation rules chosen and the integrity and sensitivity of the upstream data modules. 4.1 Upstream Inventories This section describes the main assumptions concerning the upstream models that have been used in the study. The list of upstream modules is shown in Appendix 4 with information on the data sources and relevant information Ferrous Scraps No upstream data for scrap collection, sorting and processing was included in the study. However, for external scraps the environmental burdens associated with the transportation from the scrap merchant, municipal facilities or other factories to the steelworks is included, although generally negligible. The main reason for omitting scrap burdens was because of the complexity and diversity of scrap recovery and recycling practices for all of the products, which would have extended the boundaries and extended the project time scales. However, this decision accommodates the extension of system boundaries in future studies for individual products. Similarly, no allocation procedure was applied to the use of scraps for reuse and recycling situations. This was to allow users of the data to apply consistent allocation procedures for scrap inputs and scrap recycling scenarios arising at end-of-life, as recommended in clause of ISO The issue of scrap allocation is further discussed in Appendix Electricity The grid electricity production associated with individual sites can have a significant effect on the LCI, particularly with regard to CO 2 emissions; therefore this was customised for each country. Thus, the proportion of different energy sources used for grid electricity production (e.g. % nuclear, % hydro, % thermal energy by fuel, including coal, natural gas oil, others) was adapted for each country using the reference Energy Statistics of OECD Countries, , 2000 Edition. Within the United States and Canada, the breakdown of grid electricity production was by region according to the reference Energy Agency Statistics - US Department of Energy, North American Electric Reliability Council (NAERC). The models used for each type of primary energy (e.g. coal extraction, transport and combustion in electricity power plant), however, are standard for the majority of sites (e.g. except Finland, where country specific modifications were sourced) and were sourced from Laboratorium fur Energiesysteme (ETH), Zurich 1996, and Electricité de France Thus, it is assumed that electricity production from coal, for example, has the same efficiency and environmental burdens worldwide. These approximations must be taken into consideration when interpreting the LCI data. 21