EN 19694-4:2016

Stationary source emissions - Determination of greenhouse gas (GHG) emissions in energy-intensive industries - Part 4: Aluminium industry

This European Standard specifies a harmonized method for calculating the emissions of greenhouse gases from the electrolysis section of primary aluminium smelters and aluminium anode baking plants. It also specifies key performance indicators for the purpose of benchmarking of aluminium. This also defines the boundaries.
NOTE   Other requirements and other EU Directives may be applicable to the product(s) falling within the scope of this standard.

Emissionen aus stationären Quellen - Bestimmung von Treibhausgasen (THG) aus energieintensiven Industrien - Teil 4: Aluminiumindustrie

Diese Europäische Norm legt eine harmonisierte Methode zur Berechnung der Treibhausgasemissionen aus dem Elektrolyseabschnitt von Anlagen zur Aluminiumschmelzflusselektrolyse und Anlagen, in denen Anoden gebrannt werden, fest. Darüber hinaus legt sie Schlüsselleistungskennzahlen für das Benchmarking von Aluminium fest. Dadurch sind auch die Grenzen definiert.
ANMERKUNG   Für Produkte, die in den Anwendungsbereich dieser Norm fallen, können weitere Anforderungen und weitere EU Richtlinien anwendbar sein.

Émissions de sources fixes - Détermination des émissions de gaz à effet de serre (GES) dans les industries énergo-intensives - Partie 4: Industrie de l'aluminium

La présente Norme européenne spécifie une méthode harmonisée pour calculer les émissions de gaz à effet de serre provenant du hall d'électrolyse des alumineries de production d'aluminium primaire et des installations de cuisson des anodes. Elle spécifie également des indicateurs clés pour déterminer les performances de l'aluminium. Elle définit en outre le périmètre des procédés.
NOTE   D’autres exigences et d’autres Directives UE peuvent être applicables au(x) produit(s) relevant du domaine d’application de la présente norme.

Emisije nepremičnih virov - Določevanje emisij toplogrednih plinov (TGP) v energetsko intenzivnih industrijah - 4. del: Proizvodnja aluminija

Potrjeni standard določa (opisuje) metodo izračuna za spremljanje emisij toplogrednih plinov iz primarnih talilnic aluminija, vključno s proizvodnjo anod. Emisije toplogrednih plinov vključujejo zlasti ogljikov dioksid (CO2) in perfluorirani ogljikovodik (PFC).

General Information

• Status: Published
• Publication Date: 19-Jul-2016
• Withdrawal Date: 30-Jan-2017
• ICS: 13.040.40 - Stationary source emissions
• Technical Committee: CEN/TC 264 - Air quality
• Drafting Committee: CEN/TC 264/WG 33 - Greenhouse gas (GHG) emissions in energy-intensive industries
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 15-Mar-2022
• Completion Date: 14-Apr-2025
• Mandate: M/478 - Standardisation mandate to CEN, CENELEC and ETSI for the development of EU technical standards in the field of greenhouse gas emissions
• Ref Project: SIST EN 19694-4:2017 - Stationary source emissions - Determination of greenhouse gas (GHG) emissions in energy-intensive industries - Part 4: Aluminium industry

Overview

EN 19694-4:2016 (CEN) is the sector-specific European standard for calculating greenhouse gas (GHG) emissions from the aluminium industry. It specifies a harmonized method to quantify GHG emissions originating from the electrolysis section of primary aluminium smelters and aluminium anode baking plants, defines the calculation boundaries, and sets key performance indicators (KPIs) for benchmarking aluminium production. The standard complements EN 19694‑1 (General aspects) and aligns with IPCC guidance for inventory quality and transparency.

Key topics and technical requirements

• Scope and boundaries: Focuses on process emissions from electrolysis and anode baking; direct fuel-based emissions are excluded (see EN 19694‑1).
• Greenhouse gases covered: Primarily CO2 from electrolysis and baking processes and perfluorocarbons (PFCs) - tetrafluoromethane (CF4) and hexafluoroethane (C2F6).
• Calculation methods:
  • Tiered approach (Tier 1 / Tier 2) for increased accuracy:
    • Tier 1: Process-specific equations with technology‑typical parameters.
    • Tier 2: Process-specific equations using facility-specific parameters and measurements.
  • Detailed treatment of prebake and Søderberg technologies, baking furnace emissions, anode consumption and anode effects.
• Parameters and units: Defines symbols, units and chemical formulae used in calculations (e.g., anode effects, current efficiency, emission rates).
• Verification and reporting: Includes methods for verification and guidance to produce reliable, reproducible GHG inventory data suitable for reporting and benchmarking.
• KPIs: Specifies indicators to compare emissions performance across plants or companies (tonnes CO2e per tonne aluminium, PFC rates, etc.).

Applications and who uses it

EN 19694‑4 is intended for:

• Aluminium smelter operators and plant environmental teams for internal monitoring and continuous improvement.
• GHG reporting and verification bodies preparing or validating emissions inventories for compliance, voluntary reporting or carbon management.
• Environmental consultants and auditors performing emissions assessments, due diligence or benchmarking studies.
• Regulators and policymakers using harmonized methods for sectoral emission accounting and comparison. Practical uses include facility-level emission calculations, trend analysis, benchmarking across sites or corporations, and supporting verification under national/regional reporting schemes. Note: other EU Directives or regulatory requirements may also apply to covered products/processes.

Related standards and references

• EN 19694‑1 (General aspects) - mandatory companion document for methodology, definitions and fuel-based emissions.
• Other parts of the EN 19694 series (Iron & steel, Cement, Lime, Ferroalloys).
• IPCC inventory guidance (2006) and associated technical documents referenced for methodological consistency.

Keywords: EN 19694-4:2016, aluminium industry, GHG emissions, CO2, PFC, CF4, C2F6, electrolysis, anode baking, benchmarking, emissions calculation, CEN.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2017
(PLVLMHQHSUHPLþQLKYLURY'RORþHYDQMHHPLVLMWRSORJUHGQLKSOLQRY7*3Y
HQHUJHWVNRLQWHQ]LYQLKLQGXVWULMDKGHO3URL]YRGQMDDOXPLQLMD
Stationary source emissions - Determination of greenhouse gas (GHG) emissions in
energy-intensive industries - Part 4: Aluminium industry
Emissionen aus stationären Quellen - Bestimmung von Treibhausgasen (THG) aus
energieintensiven Industrien - Teil 4: Aluminiumindustrie
Émissions de sources fixes - Détermination des émissions des gaz à effet de serre dans
les industries à forte intensité énergétique - Partie 4: Industrie de l'aluminium
Ta slovenski standard je istoveten z: EN 19694-4:2016
ICS:
13.020.40 Onesnaževanje, nadzor nad Pollution, pollution control
onesnaževanjem in and conservation
ohranjanje
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
77.120.10 Aluminij in aluminijeve zlitine Aluminium and aluminium
alloys
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 19694-4
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2016
EUROPÄISCHE NORM
ICS 13.040.40
English Version
Stationary source emissions - Determination of
greenhouse gas (GHG) emissions in energy-intensive
industries - Part 4: Aluminium industry
Émissions de sources fixes - Détermination des Emissionen aus stationären Quellen - Bestimmung von
émissions de gaz à effet de serre (GES) dans les Treibhausgasen (THG) aus energieintensiven
industries énergo-intensives - Partie 4: Industrie de Industrien - Teil 4: Aluminiumindustrie
l'aluminium
This European Standard was approved by CEN on 5 May 2016.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 19694-4:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 List of abbreviated terms . 5
5 Symbols, units and chemical formulae . 6
5.1 Symbols and units . 6
5.2 Chemical formulae . 7
6 Calculation methods – General remarks. 8
6.1 Introduction . 8
6.2 Calculation methods for process GHG emissions from primary aluminium
production . 8
6.3 Sources of carbon dioxide . 9
6.4 Sources of PFC . 9
7 Methods for calculation of process carbon dioxide emissions . 10
7.1 General . 10
7.2 Tier 1 – Method using process specific equations with technology typical parameters
for carbon dioxide emissions . 10
7.3 Tier 2 – Method using process specific equations with facility specific parameters for
carbon dioxide emissions . 10
7.4 Calculation of carbon dioxide emissions from prebake processes . 10
7.5 Baking furnace carbon dioxide emissions . 12
7.6 Calculation of carbon dioxide emissions from the Søderberg process. 16
8 Methods for calculation of PFC emissions . 18
8.1 Introduction . 18
8.2 Tier 1 method for calculating PFC emissions . 18
8.3 Tier 2 method for calculating PFC emissions . 19
8.4 Calculation of PFC emissions from aluminium reduction processes . 19
8.5 Verification of GHG calculation . 22
9 Key performance indicators. 22
Bibliography . 24

European foreword
This document (EN 19694-4:2016) has been prepared by Technical Committee CEN/TC 264 “Air
quality”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2017, and conflicting national standards shall
be withdrawn at the latest by January 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document has been prepared under a mandate M/478 given to CEN by the European Commission
and the European Free Trade Association.
EN 19694, Stationary source emissions — Determination of greenhouse gas (GHG) emissions in energy-
intensive industries is a series of standards that consists of the following parts:
— Part 1: General aspects
— Part 2: Iron and steel industry
— Part 3: Cement industry
— Part 4: Aluminium industry
— Part 5: Lime industry
— Part 6: Ferroalloy industry
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This European Standard serves the following purposes:
— measuring, testing and quantifying GHG emissions from the aluminium industry;
— assessing the level of GHG emissions performance of production processes over time, at production
sites;
— establishing and providing reliable, accurate and quality information for reporting and verification
purposes.
This European Standard can be used to measure, report and compare the GHG emissions of an
aluminium production facility. Data for individual facilities, sites or works may 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
EN 19694–1.
The European Standard 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
Section 4.4.2.4 of the 2006 IPCC guidelines [6].
1 Scope
This European Standard specifies a harmonized method for calculating the emissions of greenhouse
gases from the electrolysis section of primary aluminium smelters and aluminium anode baking plants.
It also specifies key performance indicators for the purpose of benchmarking of aluminium. This also
defines the boundaries.
NOTE Other requirements and other EU Directives may be applicable to the product(s) falling within the
scope of this standard.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 19694-1, Stationary source emissions — Determination of greenhouse gas (GHG) 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 EN 19694-1 and the following
apply.
3.1
aluminium electrolysis
section of an aluminium primary smelter where aluminium is converted from aluminium oxide to
aluminium metal in electrolysis cells
3.2
anode baking plant
production of carbon anodes for use in aluminium prebake electrolysis cells
3.3
PFC gases
gas emitted from aluminium electrolysis consisting of CF and C F
4 2 6
3.4
grid specific CO factor
CO factor (t CO /MWh) associated with the electricity delivered to a specific aluminium smelter from
2 2
their supplier
4 List of abbreviated terms
AE Anode effect
CWPB Centre-Worked prebake
DAE Direct anode emissions
DEE Direct electrolysis emissions
GHG Green House Gas
HSS Horizontal Stud Søderberg
IPCC Intergovernmental Panel on Climate Change
PFPB Point Feeder prebake
SWPB Side-Worked prebake
TIE Electrolysis electricity consumption
VSS Vertical Stud Søderberg
WBCSD World Business Council for Sustainable Development (WBCSD)
WRI World Resources Institute
5 Symbols, units and chemical formulae
5.1 Symbols and units
Symbol Quantity Unit
A Anode effects, (= frequency x average duration) minutes/cell
EM
day
A Anode effect overvoltage millivolts
EO
A Net anode consumption wt %
NC
A Ash content in baked anodes wt %
sha
A Ash content in pitch in weight % wt %
shp
A Ash content in packing coke, wt % wt %
shpc
B Baked anode production tonne/year
A
B Baked anode weight tonne
AW
C Carbon content of baked anodes, wt %
BA
C Carbon content of anode butts tonne/year
Butt
C Current efficiency for aluminium production %
E
C Emissions of cyclohexane soluble matter, kilograms per kg/tonne
SM
tonnes aluminium
E Emissions of tetrafluoromethane, kg CF per year kg/year
CF
E Emissions of hexafluoroethane, kg C F per year kg/year
2 6
CF
2 6
CO emissions in tonnes per year tonne/year
E 2
CO
E Emission factor of Packing Coke, tCO /t of Packing Coke tonne
FPC 2
Symbol Quantity Unit
CF dimensionless
F
CF
2 6
Weight fraction of
CF
CF
G tonne/year
A
 
G
AW
Weight of loaded green anodes = B
 
A
B
 AW
G Green anode weight tonne
AW
G Global warming potential. Use latest G data from IPCC tonnes CO
WP WP 2
equivalent/tonn
e
H Hydrogen content in green anode wt %
w
M Total mass of baked anodes tonne/year
BA
M Total mass of anode butts tonne/year
Butt
M Tonnes aluminium per year tonne/year
P
N Net anode consumption, tonnes per tonnes aluminium tonne/year
AC
O Oxidation factor of packing coke (typically 1 for this dimensionless
FPC
stream)
O Overvoltage coefficient for CF kg /t /mV
VC 4 CF4 Al
P Paste consumption, tonnes per tonnes aluminium tonne
C
P Packing coke consumed per tonnes of baked anode tonne
CC
P Packing coke weight tonne
CW
R Emission rates of CF , kg per tonne of aluminium produced kg/tonne
CF
Emission rates of C F , kg per tonne of aluminium produced kg/tonne
R 2 6
CF
2 6
S Sulphur content in baked anodes wt %
a
Slope coefficient for CF , kg CF per tonne aluminium per tonne/effect
S 4 4
CF
anode effect minute per cell day minute/cell day
W Waste tar collected tonne/year
t
wt Weight kg or tonne
5.2 Chemical formulae
Al Aluminium
Al O Aluminium oxide (Alumina)
2 3
C Carbon
CF Tetrafluoromethane
C F Hexafluoroethane
2 6
CO Carbon monoxide
CO Carbon dioxide
NaAlF Sodium aluminium hexafluoride (cryolite)
NaF Sodium fluoride
PFC Perfluorocarbon
6 Calculation methods – General remarks
6.1 Introduction
This standard shall be used in conjunction with EN 19694-1 which contains generic, overall
requirements, definitions and rules applicable to the determination of GHG emissions for all energy-
intensive sectors, provides common methodological issues and defines the details for applying the
rules. The application of this standard to the sector-specific standards ensures accuracy, precision and
reproducibility of the results.
6.2 Calculation methods for process GHG emissions from primary aluminium production
Figure 1 gives sources of process emissions and references to where in the standard calculation
methods are described.
Figure 1 — Decision tree for process carbon dioxide and perfluorocarbon emissions from
primary aluminium production
Process CO emissions in state of the art aluminium smelters comprise around 90 % of total direct CO
2 2
equivalent emissions, with the balance of emissions consisting of CO from fossil fuel combustion and
PFC emissions. Guidance on CO emissions from fuel combustion is not included in this document.
Methodology for calculating CO emissions from the combustion of fuel in anode baking furnaces is
described elsewhere [6, 7], while methodology for calculating process CO emissions is given in
Clause 7.
6.3 Sources of carbon dioxide
6.3.1 Electrolysis
Most of the CO emissions result from the electrolytic reaction of the carbon anode with alumina:
2Al O +→3C 4Al+3CO (1)
23 2
Carbon dioxide is also emitted during the electrolysis reaction as the carbon anode reacts with other
sources of oxygen, primarily from the air. Carbon dioxide is also formed as a result of the Boudouard
reaction where CO reacts with the carbon anode forming carbon monoxide, which is then oxidized to
form CO2. Each unit of CO2 participating in the Boudouard reaction produces two units of CO2 after air
oxidation:
CO + C→2CO (2)
22CO + O → CO (3)
2 2
All carbon monoxide formed is assumed to be converted to CO . By industry convention no correction is
made for the minute amount of carbon consumed as PFCs rather than CO emissions. No CO is
2 2
produced from cathode consumption unless there is on-site incineration and no recommendation is
included here for such operations CO emission from addition of sodium carbonate to electrolyses cells
is not included as this is added at infrequent intervals and is an insignificant source.
6.3.2 Anode baking
Another source of CO emissions, specific to prebake technologies, is the baking of green anodes,
wherein CO is emitted from the combustion of volatile components from the pitch binder and, for
baking furnaces fired with carbon based fuels, from the combustion of the fuel source. Some of the
packing coke used to cover the anodes is also oxidized, releasing CO during anode baking.
Carbon dioxide is emitted from the fuel used in the paste plant and the fuel used for firing the anode
baking furnace.
6.3.3 Aluminium smelting supporting processes
A further source of carbon dioxide emissions is fuel used in the cast house for heating of the metal
during treatment processes before casting, and some fuel may also be used in rodding operations.
6.3.4 Alumina refining
Carbon dioxide is not produced as process emission in the Bayer Process, the process through which
alumina is refined from bauxite ore. Most of the emissions associated with alumina refining are from
the combustion of fossil fuels, which are covered in the WRI/WBCSD [10] calculation tools for GHG
emissions from energy and electricity.
6.4 Sources of PFC
Two perfluorocarbon gases (PFCs), tetrafluoromethane (CF ) and hexafluoroethane (C F ), may be
4 2 6
produced during primary aluminium production.
4Na AlF +→3C 4Al+12NaF+3CF (4)
3 6 4
4Na AlF +→4C 4Al+12NaF+ 2C F (5)
3 6 26
NOTE The following recommendations for calculating PFC emissions are consistent with the inventory
guidance of the Intergovernmental Panel on Climate Change (IPCC) [6].
7 Methods for calculation of process carbon dioxide emissions
7.1 General
Direct CO emissions from aluminium production shall be calculated by using one of the following two
tiers:
— Tier 1: Process specific equations with industry typical parameters.
— Tier 2: Process specific equations with site or company specific parameters.
NOTE Tier 1 and tier 2 in this standard correspond to what is listed as tier 2 and tier 3 in the IPCC technical
guidance [6].
Reference should be made to Figure 1 as an overall guide on how to proceed when calculating direct
CO emissions. For calculation of key performance indicator tier 2 shall be used.
7.2 Tier 1 – Method using process specific equations with technology typical parameters
for carbon dioxide emissions
Tier 1 method for the calculation of total direct CO emissions shall be based on the calculation of CO
2 2
emissions from each individual process step which are then summed to calculate total emissions.
Equations in 7.4 describe the calculation of CO for prebake technologies, while 7.6 contains the
equations for Søderberg technologies.
7.3 Tier 2 – Method using process specific equations with facility specific parameters for
carbon dioxide emissions
The most accurate inventories of CO are obtained by using site or company specific data in the
equations for calculating emissions (tier 2 method). This data may come from measurements made on
site or from data from suppliers. The equations are identical to those used in the tier 1 method
described above. However, facility specific or company specific data, rather than technology typical
data, shall be used.
7.4 Calculation of carbon dioxide emissions from prebake processes
7.4.1 General
Carbon dioxide emissions resulting from CWPB and SWPB reduction technologies have as their sources
electrolysis and anode baking.
7.4.2 Carbon dioxide emissions from prebake anode consumption during electrolysis
The following equation should be used for calculation of CO emissions from prebake anode
consumption during electrolysis:
100- S - A
 
a sha
(6)
E = M ×N 3,664
CO P AC
 
 

where
are the CO emissions in tonnes per year;
E 2
CO
M is the total metal production, tonnes aluminium per year;
P
N is the net anode consumption, tonnes per tonne aluminium;
AC
S is the sulphur content in baked anodes, wt %;
a
A is the ash content in baked anodes, wt %;
sha
3,664 is the CO molecular mass: carbon atomic mass ratio,
dimensionless.
Parameters used in Formula (6) are defined in Table 2 together with technology typical values for
calculating CO emissions from prebake anode consumption during electrolysis.
Alternatively, the following equation may also be used:

(7)
E = M ×%C - M ×%C 3,664
( )
CO BA BA Butts Butts
where
E are the CO emissions in tonnes per year;
CO
M is the total mass of baked anodes, tonnes anodes per
BA
year;
% C is the carbon content of baked anodes, wt %;
BA
M is the total mass of anode butts, tonnes anodes per year;
Butts
% C is the arbon content of anode butts, wt %.
Butts
Parameters used in Formula (7) are defined in Table 1 together with technology typical values for
calculating CO emissions from prebake anode consumption during electrolysis.
Table 1 — Typical uncertainty for individual parameters and analyses used in tier 1 or tier 2
method for carbon dioxide emissions from prebake cells
Tier 1 method Tier 2 method
Data
Data
Parameter
uncertaint
Data source Data source uncertainty
y
(± %)
(± %)
Individual
M : total metal production Individual
P
2 facility 2
(tonnes aluminium per year) facility records
records
Individual
NAC: net anode consumption Individual
5 facility 5
(tonnes per tonne aluminium) facility records
records
Individual
S : sulphur content
...