ISO 19694-4:2023

INTERNATIONAL ISO
STANDARD 19694-4
First edition
2023-03
Stationary source emissions —
Determination of greenhouse gas
emissions in energy-intensive
industries —
Part 4:
Aluminium industry
Emissions de sources fixes — Détermination des émissions de gaz à
effet de serre dans les industries énergo-intensives —
Partie 4: Industrie de l'aluminium
Reference number
© ISO 2023
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 S c op e . 1
2 Nor m at i ve r ef er enc e s . 1
3 Terms and definitions . 1
4 S ymbols and abbreviated terms.2
4 .1 A bbr e v i at e d t er m s . 2
4.2 S ymbols and chemical formulae . 2
4.2.1 Symbols. 2
4 .2 .2 C hem ical f or mu l ae . 4
5 C alculation methods — General remarks . 4
5.1 G eneral . 4
5.2 C alculation methods for process GHG emissions from primary aluminium
production . 4
5.3 S ources of greenhouse gases . 5
5.3.1 Electrolysis . 5
5 . 3 . 2 A no de b a k i n g . 6
5.3.3 Aluminium smelting supporting processes . 6
5.3.4 A lumina refining . 6
5.3.5 Sources of PFC . 6
6 M ethods for calculation of process greenhouse gas emissions . 6
6.1 General . 6
6.2 T ier 1 — Method using process specific formulae with technology typical
parameters for carbon dioxide emissions . 7
6.3 T ier 2 — Method using process specific formulae with facility specific parameters
for carbon dioxide emissions . 7
6.4 C alculation of carbon dioxide emissions from prebake processes . 7
6.4.1 G eneral . 7
6.4.2 G reenhouse gas emissions from prebake anode consumption during
electrolysis . . . 7
6.5 B aking furnace greenhouse gas emissions . 8
6.5.1 General . 8
6 . 5 . 2 F uel . 8
6.5.3 Combustion of volatile matter . 9
6.5.4 B aking furnace packing material . 10
6.5.5 C alculation of greenhouse gas emissions from the Søderberg process . 11
7 M ethods for calculation of PFC emissions .12
7.1 G eneral .12
7.2 T ier 1 method for calculating PFC emissions .12
7.3 T ier 2 method for calculating PFC emissions . 13
7.4 Calculation of PFC emissions from aluminium reduction processes .13
7.4.1 Step 1 — Calculation of the emissions of each PFC gas per tonne of
aluminium .13
7.4.2 Step 2 — Calculation of the total kilogram emissions of each PFC gas .15
7.4.3 S tep 3 — Calculation of the total tonnes of carbon dioxide emissions
equivalent to the PFC emissions . 15
7.5 V erification of the GHG calculation . 15
7.5.1 Validation of the CO emission calculation . 15
7.5.2 V alidation of the PFC emission calculation . 16
8 K ey performance indicators .16
Bibliography .17
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,
Stationary source emissions.
A list of all parts in the ISO 19694 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document serves the following purposes:
— to measure, test and quantify GHG emissions from the aluminium industry;
— to assess the level of GHG emissions performance of production processes over time at production
sites;
— to establish and provide reliable, accurate and quality information for reporting and verification
purposes.
This document can be used to measure, report and compare the GHG emissions of an aluminium
production facility. Data for individual facilities, sites or works can be combined to measure, report and
compare GHG emissions for a company, corporation or group.
Direct fuel-based emissions are not included; for calculation of this part of the GHG emissions, see
ISO 19694-1.
This document deals with sector-specific aspects for the determination of greenhouse gas (GHG)
emissions from aluminium production and is based on documents mentioned under tier 3 of
[6]
Section 4.4.2.4 of the 2006 IPCC guidelines .
v
INTERNATIONAL STANDARD ISO 19694-4:2023(E)
Stationary source emissions — Determination of
greenhouse gas emissions in energy-intensive industries —
Part 4:
Aluminium industry
1 S cope
This document specifies a harmonized method for calculating the emissions of greenhouse gases from
the electrolysis section of primary aluminium smelters and aluminium anode baking plants. This
document also specifies key performance indicators for the purpose of benchmarking of aluminium
and boundaries.
2 Normat ive references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 19694-1, Stationary source emissions — Determination of greenhouse gas emissions in energy-intensive
industries — Part 1: General aspects
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 19694-1 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
aluminium electrolysis
section of an aluminium primary smelter where aluminium is converted from aluminium oxide to
aluminium metal in electrolysis cel
...