Steel LCI Methodology Report | World Steel Association

LIFE CYCLE INVENTORY METHODOLOGY REPORT

Life cycle inventory methodology report for steel products
© World Steel Association 2017
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ISBN 978-2-930069-89-0
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Table of contents
1. Introduction ...................................................................................................................... 1
1.1 Background ....................................................................................................... 1
1.2 Target audience and intended application .........................................................2
1.3 Basis of methodology ........................................................................................ 2
1.3.1 LCI study scope .....................................................................................2
1.3.2 Applicable products ................................................................................ 2
1.3.3 Overarching standards ...........................................................................3
2. Requirements for LCA studies .......................................................................................... 4
3. Study requirements ......................................................................................................... 5
3.1 Goal and scope .................................................................................................. 5
3.2 Functional unit .................................................................................................5
3.3 System boundaries ............................................................................................ 6
3.3.1 Technology coverage .............................................................................. 8
3.3.2 Geographic coverage .............................................................................. 8
3.3.3 Time coverage ........................................................................................ 8
3.4 Application of LCIA categories ........................................................................ 9
3.5 Data collection .................................................................................................. 9
3.5.1 Transport ................................................................................................ 9
3.5.2 Fuels and energy – upstream data ......................................................... 10
3.5.3 Raw and process materials – upstream data .......................................... 10
3.5.4 Emissions to air, water and soil ............................................................ 11
3.5.5 Waste for disposal ................................................................................ 12
3.5.6 Material for recovery ............................................................................ 12
3.5.7 Data quality requirements .................................................................... 13
3.5.8 Cut-o criteria...................................................................................... 14
3.5.9 Flares ................................................................................................... 14
3.5.10 Data validation ..................................................................................... 14
3.6 Methodological details .................................................................................... 14
3.6.1 Co-products ......................................................................................... 14
3.6.2 Steel scrap ............................................................................................ 16
3.7 Interpretation .................................................................................................. 18
3.8 Critical review ................................................................................................. 18
4. Appendices .................................................................................................................... 19
Appendix 1: Steel product manufacturing flow diagrams via the BOF and
EAF routes .............................................................................................................20
Appendix 2: Recycling methodology description ................................................... 22
Appendix 3: Critical review report ......................................................................... 32
References ......................................................................................................................... 34

iv
List of figures
Figure 1: System boundaries overview for cradle-to-gate system ..............................6
Figure 2: System boundaries overview for cradle-to-gate with recycling system ...... 7
List of tables
Table 3-1: Example accounted air and water emissions ...........................................12
Table 3-2: Steelmaking co-products ....................................................................... 15
Acronyms
ADP Abiotic depletion potential
AP Acidication potential
BF Blast furnace
BF Gas Process gas produced in the blast furnace
BOF Basic oxygen furnace
BOF Gas Process gas produced in the basic oxygen furnace
CO Gas Process gas produced in the coke ovens
CRP Critical review panel
EAF Electric arc furnace
ECCS Electrolytic chrome coated steel (tin-free steel)
EP Eutrophication potential
EPD Environmental product declaration
GWP Global warming potential
HDG Hot dip galvanised steel
HRC Hot rolled coil
LCA Life cycle assessment
LCI Life cycle inventory
LCIA Life cycle impact assessment
NCV Net caloric value
ODP Ozone depletion potential
POCP Photochemical ozone creation potential

1
Introduction
1. Introduction
1.1 Background
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 speciers, in a world where
sustainable development is a key issue, is the associated environmental performance of material
applications both from a manufacturing and a 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, which is
referred to as the ‘cradle-to-grave’ approach.
As per ISO 14044: 20061, LCA generally comprises four major components:
• Goal and scope denition;
• Life cycle inventory (LCI) - data collection and calculation of an inventory of materials,
energy and emissions related to the system being studied;
• Life cycle impact assessment (LCIA) - 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.
is LCI methodology has been produced by the World Steel Association (worldsteel)
to outline a steel specic standard based on ISO 14040: 20062 and ISO 14044: 2006,
internationally agreed and universally applicable, to quantify resource use, energy and
environmental emissions associated with the manufacture of steel industry products, from
the extraction of raw materials in the ground through to the point at which they are ready
to be shipped from the steelworks (steel factory gate). e methodology has been developed
over many years, and was rst published as part of an LCI study report in 1995/63. It has
subsequently been updated in 20004, 20055 and most recently in 20116. Global and regional
steel LCI data was published alongside each of these updates and the methodology was
critically reviewed by a panel of external LCA experts. is document is intended to collate
and clarify the worldsteel methodology in a format that provides clear principles to be applied
in steel product LCI studies.
In previous worldsteel LCA updates, a full LCA methodology report, which included both the
methodology and the study results, was published. In order to enable third parties to use this
methodology and to simplify the publication of future worldsteel updates, the study reports are
generated independently of this methodology report. For LCI data generated following this
methodology, a separate study report shall be produced. To be conformant with ISO 14044:
2006, this study report shall also undergo a review as described in the standard.