Review Comments by Governments on the Second Order Draft of Volume 3 of 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories
Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

6908

3

3

5

5

There are no the phrase like "Parts in brackets – comments from
Republic of Korea
Authors/issues that may be refined" in Chapter 6 or "Bracketed text –characterization of guidance as new, updated, and/or elaborated" in
Chapter 7.

Noted

The refinement Final Drafts have been formatted in a manner consistent
with IPCC task-force recommendations, in order to highlight to users: (i)where text has been updated; (ii) where there is new guidance; and (iii)
where there has been no refinement.

6906

3

3

154

154

It wolud be better to add revised or newly added contents first (infront of introduction) like Chapter 6.

Republic of Korea

Accepted withmodification

6486

3

3

188

192

The difference in labels between table 3.3 (new) and table 3.3(updated) is not clear enough. Why are they not table 3.3 and 3.4?

United Kingdom (of GreatBritain and Northern Ireland)

Noted

Across the 2019 Refinement, the changes to text, tables and so on aredetailed within the Mapping Tables. Where appropriate in the IPPU
Final Drafts, text is included in individual sections of text to assist users
to understand the refinements made, to help inventory compilers in crossreferencing with the 2006 Guidelines.
At this stage the authors adopted the agreed conventions in order not tochange the numbers of the tables of the whole volume 3 and be able toeasily identify what has been new and what has been updated.

868

3

3

556

557

Missing unit on the emission factors of “0.019” and “0.04”. Please
add the unit of “kg HFC-23/kg HCFC-22” after “0.019” and “0.04”.

ThailandAccepted

We agreed with the commenter and have added the appropriate units forthe emission factor.

1806

3

3

730

739

In lines 730-732, 766-768, and 777-780, please check the formulas(3.41A), (3.42) and (3.43), and it is suggested to reformulate the text
on the right of the formula as a formula.

China

Accepted

We reviewed Equations 3.41A, 3.42, and 3.43 as suggested by thecommenter. We reviewed Equation 3.41A for accuracy and updated thetext that describes the units. We reviewed Equations 3.42 and 3.43 foraccuracy and did not find errors. For each of these equations, weremoved the text note from the right hand of the formula and added it to
the description of the variables below the equations.

4700

3

3

915

916

Japan
To have a generalized GHG EF specified for fluorochemical
production, without the F-gas specified seems to be inconsistent with
8.2.6 in Volume 1, and lowers transparency. Is it possible for instanceto provide EFs for each of the F-gas species shown in Table 3.28B
instead?

Noted

While we agreed with the reviewer that it is desirable to develop a
specific emission factor for each fluorinated GHG, we also note that thedataset that was used to provide the default emission factor does nothave sufficient detail to enable such a calculation. We anticipated thatuse of the default emission factor in Table 3.28A along with use of therepresentative composition in Table 3.28B in essence provides
fluorinated GHG default emission factors. For example, the default
emission factor value of 0.04 kg fluorinated GHG emissions/kg
fluorochemical produced, times the production value in kg
fluorochemical produced, times 0.12 perfluorocyclobutane from Table
3.28B would provide a de facto default emission factor for
perfluorocyclobutane of 0.0048 kg perfluorocyclobutane/kg
fluorochemical produced. If the inventory compiler has some
information regarding the type of fluorochemical manufacturing that is
occuring, either limited or full information, they could use that
information to estimate the particular fluorinated GHG being emitted inconjunction with the default EF, or use the default EF and theinformation in Table 3.28B to assume a chemical composition for theemission. The inventory compiler could also use a Tier 2 or 3 approach.

870

3

3

947

958

Numbers indicated emission factors in the whole paragraph are notclear without unit. Are these numbers in percent or kg emission/kg
produced?Adding unit after each number would greatly clarify thecontent in this paragraph.

Accepted

We agreed with the commenter and have added the appropriate units, kg
emitted/kg produced, for all EFs in this section.

ThailandComment ID Volume Chapter From line To line
7402

3

3

1060

1736

7574

3

3

1090

1092

5626

3

3

1090

1092

7572

3

3

1212

1241

5628

3

3

1381

1382

5630

3

3

1433

1434

Comment

Country

Response

Authors notes

It is well explained that combustion related emissions should be
Germany
reported under 1.A.1.b, leakage under 1.B.2.iv-v and all process
related emissions under 2.B. However, there is still a high chance of
misinterpretation regarding the allocation of emissions from refineries
with integrated chemical industries and some processes need to be
explained in more detail. In the 2006 Guidelines and also in therefined guidelines, the allocation of stored refinery products is notstraight forward. In chapter 4 Volume 2 line 1951, it is stated that
only fuels should be reported under 1.B.2.a.v, and in Volume 3 e.g.
under 3.9.2.2 (page 3.74 in 2006 Guidelines) storage of feedstock ispart of methanol production. Other production processes provide
neither emission factors nor methods for feedstocks. Countries withboth refineries and chemical industries will need to apply a complex
reporting system with this differentiation, while others with chemicalindustry only would underestimate their emissions. If countries
produce products dedicated for export (e.g. naphtha or LPG),
emissions cannot be reported with the refined guidelines.
A second incomprehensible aspect is asphalt blowing. This aspectused to be part of chapter 3 (page 5.14) – now it is included under
1.B.2.a.iv (Volume 2, chapter 4, line 1931). It should be clear where
to report emissions from asphalt blowing in order to avoid double
counting.
For both aspects, we recommend providing a graphical presentation,
where to report such emissions.
In earlier guidelines, there were no mention, that CO2 emissions from Finland
biological feedstocks in IPPU sector have to be reported as a memo
item. This need to report the CO2 emissions from use of biomass as
feedstocks in the IPPU sector as a memo item does not appear to be
included in the original draft Table of Contents /Chapter Outline asattached to the Terms of Reference for the 2019 Refinement either.

Noted

Reallocated to Energy

Rejected

It is within the scope of hydrogen production, which is within the TOC.

Recommend editing this sentence from lines 1090 to 1092 related to United States of America
biomass use. "Emissions of CO2 from thermochemical processes likesteam reforming and gasification using biomass as feedstock shouldbe accounted for in a memo item, and not included in national totals."
Recommend removing "and not included in national totals" because it
is already included in national totals from the AFOLU chapter incarbon stock changes. Suggested sentence: "Emissions of CO2 fromthermochemical processes like steam reforming and gasification using
biomass as feedstock should be accounted for in a memo item only to
avoid double counting."
Box 3.18: If there is still no evidence that CH4 and N2O emissions
Finlandwill occur from hydrogen production, this box (or related information)
should be placed in an appendix.
Recommend editing this sentence from lines 1381 to 1382 related to United States of America
biogenic use for hydrogen production, "If the feedstock is biogenic,
the CO2 emission should be allocated to a memo item and notincluded in national totals". Recommend editing to read as: "If thefeedstock is biogenic, the CO2 emission should be allocated to amemo item to avoid double-counting as these emissions are alreadycaptured in national totals."
Remove "and exclude it from national totals."
United States of America

Accepted withmodification

The revised text makes even closer reference to the AFOLU chapter.

Rejected

The box is describing an exclusion due to negligible amounts and scarcescientific basis, while the scope of the appendix is suggestions forfurther methodological development.
The revised text makes even closer reference to the AFOLU chapter.

Accepted withmodification

Accepted withmodification

Changed from "national totals" to "the Hydrogen production sector".

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5632

3

3

1470

1470

Remove "and exclude it from national totals."

United States of America

Accepted withmodification

Changed from "national totals" to "the Hydrogen production sector".

5634

3

3

1500

1500

Remove "and exclude it from national totals."

United States of America

Accepted withmodification

Changed from "national totals" to "the Hydrogen production sector".

5636

3

3

1601

1602

Remove "excluded from national totals and"

United States of America

Changed from "national totals" to "the Hydrogen production sector".

5638

3

3

1611

1611

Remove "excluded from national totals and"

United States of America

Accepted withmodification
Accepted withmodification

5640

3

3

1623

1623

Remove "excluded from national totals and"

United States of America

6912

3

4

5

5

6910

3

4

198

199

There are no the phrase like "Parts in brackets – comments from
Republic of Korea
Authors/issues that may be refined" in Chapter 6 or "Bracketed text –characterization of guidance as new, updated, and/or elaborated" in
Chapter 7.
It wolud be better to add revised or newly added contents first (inRepublic of Korea
front of introduction) like Chapter 6.

6766

3

4

251

251

872

3

4

297

298

6768

3

4

300

301

6770

3

4

305

305

874

3

4

343

5200

3

4

484

484

5202

3

4

512

512

Changed from "national totals" to "the Hydrogen production sector".

Accepted withmodification
Noted

Changed from "national totals" to "the Hydrogen production sector".

Accepted

Review of changes included before introduction. However, this will also
be summarised in the Mapping Table.

Russian Federation

Rejected

The coke production is a fuel transformation (it is not only a combustion
for firing the coke ovens). Tier 1b addresses coking coal AD to be used
for CO2 estimates along with coke production AD for a simplified
carbon balance which assumes that 100% of COG is burned onsite forenergy recovery and that all coke oven by-products are transferredoffsite.

ThailandAccepted

This shaded parts include description of "NO" emissions. NO - notoccured.

Russian Federation

Accepted withmodification

Regarding CH4 decision tree a new one will be included in FD.

Russian Federation
Figure 4.8 does not provide decision tree for CH4 emissions fromcoke production. It provides decision tree for CH4 emissions fromiron and steel production. So decision tree for CH4 emissions fromcoke production is missed and it is not clear how to choose the propertier for CH4 emissions estimation from coke production
Two equations are on the same line causing confusion for
Thailandreaders.Add a new line for ECH4, energy = CO• EFCH4 separating
the two equations.

Accepted withmodification

Regarding CH4 decision tree a new one will be included in FD.

Accepted

The equations were separated in FD, however the equation 4.1 is forCO2 and the equation 4.1a is for CH4.

Add the same sentence as for the Tier 1 method: “Total emissions are France
the sum of Equations 4.9, 4.10 and 4.11.”
To avoid confusion with the blast furnace for the iron production,
Francereplace “blast furnace” by “ignition furnace” in the sentence: “COG:
quantity of coke oven gas consumed in ignition furnace in sinterproduction (…)”

Accepted withmodification
Accepted withmodification

Some recommendations/clarifications for energy experts should be
provided in this section how to keep (preserve) fuel balance forenergy sector in case when production activity data are used for
estimation emissions from 1A1c category and fuel combustion AD
are used for all other categories in the sector 1A. The use of
methodology suggested in the section 4.2.2.1 of Vol.3 Ch.4 SOD
Refinements 2019 for estimation of emissions in category 1A1c willlead to increase of difference between Reference and Sectoral
approaches in Energy sector.
What would be the meaning of gray shade in Table 4.1 A? It is
unclear.It would be more explicit with symbol (or “X”) than grayshading.
There are three tiers for CO2 and two tiers for CH4. It is not clear
which tier should be used for CH4 In case is tier 2 is used for CO2.
Estimates for CO2 and for CH4 will be incomparable in this casebecause of the different AD used for different tiers.

The format of how to highlight updates, new guidance and no
refinements will be done consistent with IPCC task-force
recommendations

FD text was changed to: quantity of coke oven gas consumed in ignition
furnace for sinter production.

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

1808

3

4

524

739

In lines 524-528, 730-731, and 735-739, because coke oven gas, blast China
furnace gas and converter gas power generation are typical energy
activities, it is suggested that their emissions be calculated andreported in the energy activity inventory.

Rejected

5204

3

4

572

572

5206

3

4

636

636

Add the sentence: “Total emissions are the sum of Equations 4.12,
France4.13 and 4.14.”
FranceWhy are there 2 rows for the BOF?
We may assume that the EF of 1.39 (VS the current one in GL 2006:
1.46) is the new EF proposed for the 2019 Refinement. But, if we donot mistake, the EU ETS benchmark value under the EU ETS phase 3(2013-2020) Decision 2011/278/UE, annex I, Table 1, is 1.328
allowances/t (i.e. t CO2/t) and not 1.39 (in the annex I: row “Hotmetal” which includes the BOF).

Accepted withmodification
Accepted withmodification

The Chapter 2 "Stationary combustion" from the Volume 3 is providing
the explanation that the reporting of emissions from gases obtained fromprocessing feedstock and process fuels obtained directly from thefeedstock follows the principle stated in Section 1.2 of Volume 3. In
summary, if the emissions occur in the IPPU source category which
produced the gases emitted they remain as industrial processes
emissions in that source category. If the gases are exported to anothersource category in the IPPU sector, or to the energy sector, then the
fugitive, combustion or other emissions associated with them should bereported in the sector where they occur. Inventory compilers arereminded to discriminate between emissions from processes where thesame fossil fuel is used both for energy and for feedstock purposes (e.g.
synthesis gas production, carbon black production), and to report theseemissions in the correct sectors. The information for clarification ofemissions to be split between Energy and IPPU is provided in the Box
1.1, Introduction to the IPPU Chapter.
FD text was changed to: Total emissions are the sum of Equations 4.12,
4.13 and 4.14. for the processes that occur in the country.
Table 4.1 has the oldest EF deleted. New references has been found andaA value of 1.58 has been now included

876

3

4

655

Thailand
EFCH4 for coke production has wide range, 1-80 g CH4/tonne ofcoke produced (Table 4.2).Is it possible to make sub-category of cokeproduction process to provide alternative of selecting appropriate EF,
e.g., old technology process, 1970s technology, BAT process,with/without offgas-recirculation technology, etc.

Accepted withmodification

The upper value has been considered for Tier1, that is coherent withother new value reported by Japan.

7576

3

4

655

656

FinlandDefault emission factor for CH4 emissions from coke production:
According to the reference given for the default emission factor, thefactor is from a single plant and therefore could not be used as
default. Please use more comprehensive references for calculation of a
default emission factor or state that no default can be given.

Accepted withmodification

The upper value has been considered for Tier1, that is coherent withother new value reported by Japan.

6914

3

4

679

680

Tier2 material specific carbon contents are updated but, In energy
Republic of Korea
sector carbon emission factors are not changed, so it need to consider
the revision EF in energy sector for consistency.
Especially emission factors of new guidance for fugitive emissions
from coke production in energy sector(Volume3, Chapter4, Line2796~2797) are different with IPPU sector eventhough emission
source is samee.g) Blast Furnace Gas(IPPU) 0.17tC/ton -> 0.243tC/ton(Updated)(Energy) 2.47TJ/Gg * 70.8kg/GJ / 10^3 = 0.17tC/ton(notupdated)Accepted withmodification

The Table 4.3 carbon contents for fuels has been leave as in 2006
Guidelines. For the rest of the process material, has been updated.

Comment ID Volume Chapter From line To line

Comment

Country

Response

5210

3

4

737

743

The split (export (à Energy) VS internal needs (à IPPU)) seems to be France
very tricky to do for the operators. But I am waiting for their feedbackon that question.

Noted

4702

3

4

746

746

Japan
The method of treating coke use as energy-use is adopted in many
countries. This method was originally developed by World Steel
Association in 2007 and was published as International standard
ISO14404 in 2013. Furthermore, the IEA energy statistics manual
also defined that "all cokes should be treated as transformation use in
the blast furnace. ~Never report the use of coke in blast furnace as"non-energy use" ".Thus, the method of treating coke use as energyuse has been widely adopted in the world, including in privatecompanies, national governments and international organizations.
As stated in paragraph 721, it is difficult to calculate CO2 emissions
for the Energy Sector and the Industrial Processes Sector separately
without any ambiguities. Taking into account the above, the following
sentence should be added to the end of the "RELATIONSHIP TO
THE ENERGY SECTOR" section in order to request Parties which
do not follow the allocation rule described in paragraph 730 to 745
due to their national circumstances and data availability to provide
clear explanation on which emissions are reported under which
category.
"The clear explanation on the allocation of emissions should be
provided in order to make sure that there is no double counting andomissions when the emissions from iron and steel production are notreported as described above."

Accepted withmodification

5642

3

4

747

750

The addition of Figure 4.8a is useful to map how to allocate CO2
United States of America
emissions between Energy and IPPU for integrated Iron and Steelfacilitates, but this figure is difficult to follow the flow of emissions
through the process and whether they are under IPPU or Energy.
While the figure is helpful, further revisions could be made to further
clarify. This could even be expanding Figure 4.8a to take up an entire
page, similar to Figure 4.1 between lines 245 and 246, which would
allow more space to see the flow of emissions to be allocated.

Accepted withmodification

Authors notes
The Chapter 2 "Stationary combustion" from the Volume 3 is providing
the explanation that the reporting of emissions from gases obtained fromprocessing feedstock and process fuels obtained directly from thefeedstock follows the principle stated in Section 1.2 of Volume 3. In
summary, if the emissions occur in the IPPU source category which
produced the gases emitted they remain as industrial processes
emissions in that source category. If the gases are exported to anothersource category in the IPPU sector, or to the energy sector, then the
fugitive, combustion or other emissions associated with them should bereported in the sector where they occur. Inventory compilers arereminded to discriminate between emissions from processes where thesame fossil fuel is used both for energy and for feedstock purposes (e.g.
synthesis gas production, carbon black production), and to report theseemissions in the correct sectors. The information for clarification ofemissions to be split between Energy and IPPU is provided in the Box
1.1, Introduction to the IPPU Chapter.
The Chapter 2 "Stationary combustion" from the Volume 3 is providing
the explanation that the reporting of emissions from gases obtained fromprocessing feedstock and process fuels obtained directly from thefeedstock follows the principle stated in Section 1.2 of Volume 3. In
summary, if the emissions occur in the IPPU source category which
produced the gases emitted they remain as industrial processes
emissions in that source category. If the gases are exported to anothersource category in the IPPU sector, or to the energy sector, then the
fugitive, combustion or other emissions associated with them should bereported in the sector where they occur. Inventory compilers arereminded to discriminate between emissions from processes where thesame fossil fuel is used both for energy and for feedstock purposes (e.g.
synthesis gas production, carbon black production), and to report theseemissions in the correct sectors. The information for clarification ofemissions to be split between Energy and IPPU is provided in the Box
1.1, Introduction to the IPPU Chapter.

The Figure 4.8 was modified to make it more clear and accessible.

Comment ID Volume Chapter From line To line

Comment

Country

Authors notes
The comment is mostly excepted excluding the changing of the namingfrom "LDG" to "BOF". We should also consider the naming BOFg inthis case because we are dealing with a gas.

Accepted

The uncertainty for Tier 1 was recalculated.

United States of America
The sentence at lines 932-933 reads in part: "countries should makeevery effort to us higher Tier methods because emission rates canvary greatly, and the uncertainty associated with Tier 1 factors is veryhigh." This is true for most countries, but as indicated by the decision
tree (Figure 4.12), Tier 1 is not the best approach for countries where
the PFPBmw technology prevails. Therefore recommend inserting asentence reading "The sole exception is countries where the cell
technology is Point-Feed Prebake without fully automated anodeeffect intervention strategies, where use of higher Tier methods islikely to result in less accurate emissions estimates."

Accepted

Included in text

958

Recommend inserting "identified as" between "typically" and"emission" for consistency with previous paragraph.

United States of America

Accepted

Changed in text

973

976

Rejected

The decision tree was slightly modified in the final draft, but the main
purpose of the comment still applies. However, there was no
modification to the text because the reason we recommend to use Tier 1
for "technologies without fully automated anode effects termination
strategies" is based on the inconsistent AE definition within this type oftechnologies which made it impossible to define a representative Tier 2
coefficient for this category (as described in Table 4.16). FInally, if data
is available, and EF specific for the facility is available, it isrecommended to use Tier 3 in the decision tree.

4

975

976

Accepted

Changed in text

4

985

986

These lines contradict the decision tree, which recommends use of the United States of America
Tier 1 method for the PFPBmw technology even if process data are
available. Assuming that the decision tree is correct, recommend
making two changes. In line 975, insert "generally" between"uncertainty associated with higher Tier methodologies is" and"significantly lower than that for Tier 1," In line 976, insert a new
sentence after "if this is a key category": "The only exception iscountries where the cell technology is Point-Feed Prebake without
fully automated anode effect intervention strategies, where use ofhigher Tier methods is likely to result in less accurate emissions
estimates, as discussed below."
Recommend replacing "Tier 2 and Tier 3 are strongly recommended" United States of America
with "it is good practice to use Tier 2 and Tier 3"
For clarity, recommend deleting "focus the methods with reference to" United States of America
and replacing with "focus on"

Accepted

Changed in text

3

4

748

748

878

3

4

847

5644

3

4

932

933

5646

3

4

957

5648

3

4

5650

3

5652

3

FranceIn the Figure 4.8a(new):
Change « LDG » into « BOF » in order to be consistent with theoverall document, where LDG is not used.
For the Power Plant box, for 1 and 2: after “Energy”, add: “(electricity
and/or heat production)”.
For the black box on “Heat (hot rolling mills (…)”: delete the brackets
and add “Heat used for rolling mills (…)” to avoid any confusion withthe “Energy produced” in the black box “Power Plant” (for which theallocation of the CO2 emissions depends on the use of the energy).

Response
Accepted withmodification

5208

The uncertainty of Tier 1 ( ±40%) is likely to exceed this number if
compliers use the lower end default of 1 and the upper end of 80 g
CH4/tonne of coke produced from Table 4.2.Provides EF for subcategory of coke production process based on technology used withdata from the industry in Europe, US., Japan, India, China.

ThailandComment ID Volume Chapter From line To line

Comment

Country

Authors notes
Reference to high performing facilities was removed due to thecontradiction between HVAE and LVAE recommendations.

Accepted withmodification

Have included some wording to be consistent and provide a high level
overview of rationale with reference to Marks and Nunez 2018a forfurther details.

Recommend either combining Equations 4.25 and 4.25(a) for HVAE United States of America
and LVAE or explaining why they and their associated coefficientsare presented separately (e.g., to permit use of Tier 1 LVAE
calculations in association with Tier 2 or 3 HVAE calculations forprevious years).
Multiple papers (Marks & Nunez, 2018, Dion, et Al 2018) show that United States of America
much of the CF4 production during anode affects occur within thefirst 1-2 minutes (the non-linearity is pointed out on line 1125, but
not otherwise discussed). However, many facilities do not consider
anode effects to have occurred unless they exceed a certain amount oftime, e.g. 15 - 90s (Referred to as "twinkle" AEs in Wong et Al 2015).
It would be useful to emphasize the importance of counting shortduration anode effects.

Accepted withmodification

Have included some wording to explain coefficients are presented toallow for flexibility in the adoption of different Tiers for HV and LV.

Noted

There is reference throughout the chapter that anode effect definitions
differ. We have specified the duration 'typically' associated with AEs
and have provided a separate technology class for those facilities thattypically define and approach AEs using different criteria (PFPB MW)

1152

The Tier 2b approach by Marks and Nunez does not include a formula United States of America
for calculating C2F6 emissions. It is unclear how to calculate C2F6
emissions using this method.

Accepted

Guidance has now been provided for C2F6 emissions in Tier 2b. This
will be calculated using the ratio of C2F6/CF4 multiplied by HVAE-CF4
emissions, as per Tier 2a slope and overvoltage methods.

1141

1143

Recommend including a second equation in Equation 4.27A to coverC2F6 emissions.

United States of America

Accepted

Guidance has now been provided for C2F6 emissions in Tier 2b. This
will be calculated using the C2F6/CF4 ratio, multiplied by HVAE-CF4
emissions, as per Tier 2a slope and overvoltage methods.

1141

1143

Recommending simplifying Equation 4.27A by combining the two
multiplied "AEDi" terms and adding "1" to the exponent "K2."

United States of America

Accepted

The correction was done.

3

4

1000

1005

5656

3

4

1027

1028

5658

3

4

1030

1057

5660

3

4

1073

1080

5662

3

4

1132

5670

3

4

5672

3

4

It is unclear whether this section is or is not recommending that Tier 3 United States of America
measurements be made at facilities with low HVAE frequency. Lines
1000-2002 read "For high performing facilities with low HVAE
frequency, the Tier 3 method will likely not provide a significant
improvement in the overall facility GHG inventory in comparison
with the Tier 2 Method to estimate emissions from HVAE."
However, lines 2002-1003 appear to contradict this statement:"However, the impact of LVAE emissions may still be significant andTier 3 methods are recommended to correctly assess the GHG
inventory of individual facilities." Please clarify this one way or theother.
United States of America
To ensure this sentence is consistent with the decision tree (Figure4.12), recommend adding "or when the cell technology is Point-Feed
Prebake without fully automated anode effect intervention strategies."
The authors should then explain this exception, e.g., drawing on
Marks & Nunez, 2018a: "Application of the Tier 2 and Tier 3
methods to Point-Feed Prebake without fully automated anode effectintervention strategies is likely to lead to inaccurate results.
[Following two sentences are from pages 1520-21 of Marks & Nunez,
2018a:] Process data for anode effect frequency and duration [in the
PFPBmw technology] [is] either not available or not comparable todata [for other technologies]. In some instances, cell voltage
increases in excess of 8V, the voltage most commonly used to define
anode effect trigger voltage [for other technologies], are not recorded
as an anode effect [for the PFPBmw technology] unless the duration
exceeds two minutes. Given that PFC emission rates are typicallyhighest during the first two minutes of an anode effect, this definition
prevents capture of the most relevant process data."

Response
Accepted

5654

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5668

3

4

1141

1160

Recommend that authors either choose one of the two Tier 2b/3b
equations (4.27A or 4.27B) or that they develop guidance explaining
how inventory compilers should choose between them based on
country- or facility-specific circumstances. Equation 4.27A may besomewhat simpler than Equation 4.27B in that it uses default
constants (values for K1 and K2) rather than requiring the facility or
inventory compiler to calculate these constants; however Equation
4.27A requires three sets of values (total of 6) whereas Equation
4.27B requires only four values of C1, C2, C3, and C4.

United States of America

Rejected

There is too little indications on the range/and level of accuracy of eachequations to recommend one equation rather than the other for specificcontext. However, we've added the level of uncertainty associated to thedifferent Tier 2b methodology (legacy and modern smelters) in order tohelp and make more informed decision.

5664

3

4

1141

1161

United States of America
Equations 4.27A and 4.27B seem to have excellent agreement interms of CF4 produced (assuming 4.27B is in grams, not kilograms)
as a function of AED at 300 kA (if you use Faraday's law to convert
kA to the theoretical MP); however, the results differ significantly atother line currents (or other equivalent t Al per cell per day). This islargely due to the fact that 4.27A has a linear relationship with line
current, whereas 4.27b does not (it's parabolic and peaks at ~ 290kA). Dion et Al 2008A indicates that a linear relationship is likely
not accurate, at least for high amerage smelters. It would be useful if
guidance was given as to what range of line currents (or metal
production/cell-day) each equation should be used (is one moreaccurate at low amperages and the other at high amperages? and isthere a range where neither is suitable?). From Dion 2018b, it seems
like the g/t Al of CF4 produced for a particular AED is dependent on
the metal production per day (i.e. Amerage of the technology) andthus, using the Marks & Nunez approach for all technologies would
be inappropriate (as the g CF4 per t Al are independent of technologytype). Currently the approaches are presented independent of any
guidance about which equation to use, but the choice of equation
may result in drastically different estimated emissions.

Rejected

There is too little indications on the range/and level of accuracy of eachequations to recommend one equation rather than the other for specificcontext. However, we've added the level of uncertainty associated to thedifferent Tier 2b methodology (legacy and modern smelters) in order tohelp and take a more accurate decision.

5666

3

4

1141

1161

United States of America
It is unclear if the equations for Tier 2B are considered valid for alltechnology types for which you can use a Tier 2 method. It seems
unlikely that these equations would be accurate for all technology
types given the range of slope coefficients given in Table 4.16. Please
add guidance regarding for which technology types Tier 2b isappropriate.

Accepted

Guidance on which technology types the methods apply to has been
included.

880

3

4

1151

1152

New guidance for estimating HVAE emissions in Tier 2b method
seems unclear when it involves the emission rate coefficients (K1,
K2) in Equation 4.27A without citing Table 4.16A at the end.Add“(see Table 4.16A)” at the end of line 1151.

Thailand

Rejected

Reference for equation 4.27A to Table 4.16a is done in the line above
the equation box. (regarding value of K1 and K2)
Reference for equation 4.27b to equation 4.27d is done in the line before
the equation box. (For calculation of C1,C2,C3 and C4)

882

3

4

1157

1174

Similar concerns for the new guidance on the distinction of emission
rate coefficient (C1 vs. C2, and C3 vs. C4) in Equation 4.27B.Add“(see Equation 4.27D” at the end of line 1171

Thailand

Rejected

5674

3

4

1157

1278

Equation 4.27B appears to be in grams not kilograms (based on using United States of America
the coefficients starting on line 1267), as indicated in line 1165.

Accepted

Reference for equation 4.27A to Table 4.16a is done in the line above
the equation box. (regarding value of K1 and K2)
Reference for equation 4.27b to equation 4.27d is done in the line before
the equation box. (For calculation of C1,C2,C3 and C4)Corrected the equation

5676

3

4

1170

1170

Recommend clarifying definition of "MP" by removing "technology" United States of America
after "cell." "Cell technology" could be read to encompass the entire
potline or smelter.

AcceptedLine was edited and a footnote was added to give additionnal
explanations.

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5678

3

4

1177

1204

Box 4.2A appears to include guidance. My understanding is that
United States of America
boxes are not supposed to include guidance, but to provide examples.
If the authors wish to retain the guidance, it should be removed fromthe box.

AcceptedBox has been retained for definitions / description of a cell start-up.
Guidance has been removed from the box and is now a new guidance
sub-section.

5680

3

4

1177

1204

United States of America
Box 4.2A includes potentially helpful guidance on accounting
specifically for cell startups, but this guidance needs to be better
integrated into the guidance in the remainder of the section. For
example, the authors should explain (or point to references that
explain) how "cell startup" is defined. They should also explain how
to avoid either double-counting or underestimating HVAE and LVAE
emissions that occur during cell startups and at other times. The
current guidance in Box 4.2A does not mention LVAE emissions atall, but lines 1211 through 1213 below the box indicate that startups
have unusually high LVAE/HVAE ratios. This indicates that ignoring
LVAE emissions during cell startups could lead to significant
underestimates of emissions.

Accepted

Box now defines cell start ups, and note on not double-counting start-up
emissions with normal operation emissions.
Box also includes a brief description of LVAE emissions.
Guidance is now provided outside the box, including available Tiermethods to account for cell start up emissions, both HVAE and LVAE

5682

3

4

1177

1204

United States of America
The guidance regarding developing emission factors for cell startup
should address whether it is worthwhile to develop such factors if the
facility is using the Tier 2b or 3b methods, which account for anodeeffect duration.

Accepted

Wording has been adjusted that suggests Tier 2b-3b non linear method
for Startup HVAE emissions is on equal footing to Tier 3d facility
specific total emissions for cell start-up

5684

3

4

1203

1204

The statement "Such modifications to the detection threshold should United States of America
be specific to each facility, based on historical data" is unclear. Do theauthors mean "Facilities should use the same voltage threshold toapply EFcsu as they used to develop it"?

Accepted

Clarification has been provided, the same detection threshold for AE
during cell start-up should be the one used for accounting of cell start-up
emissions

5686

3

4

1210

1213

The authors should clarify whether straight (i.e., unweighted)
averages are used for the emission factors or whether weighted
averages are used. Both "average" and "weighted average" are usedcurrently, leading to confusion.

Noted

We have removed T2 ratio which differed in its approach so this is nolonger an issue.

United States of America

Comment ID Volume Chapter From line To line

Comment

Country

5688

3

4

1210

1213

The authors either should use averages (straight or weighted) to
United States of America
estimate default emission ratios for LVAE emissions or should better
justify their use of alternative statistics (e.g., the median). The draft
currently states, "The median is used for select technology classes
where the weighted average was skewed due to a small number ofvery high LVAE/HAVE ratios in the dataset which were reflective of
unusual conditions e.g., start up." However, in one of the source
papers for the section (J. Marks and Nunez, P., "Updated Factors for
Calculating PFC Emissions from Primary Aluminum Production,"Light Metals), the authors of the paper state, "if the intended use [ofthe ratios] is to calculate a collective national or global inventory, theaverage ratio may be the better alternative [than the median]" (p.
1523). The goal of the Refinement is to provide guidance fordeveloping national inventories, indicating that the average should be
used. In general, as long as the sample set (aluminum smelters whose
emissions were measured) is representative of the modeled set(aluminum smelters in general), an average should be used. Outliers
often exist in both sample sets and modeled sets. In this case, theunusual conditions cited (cell startups) are likely to exist in allaluminum smelters at one time or another. In order to justify using astatistic other than the average for an EF, the authors need todemonstrate that startups are overrepresented in the sample set
relative to the modeled set. Even if startups are overrepresented, thebest solution may be to calculate a weighted average EF, giving lessweight to the measurements reflecting cell startups, rather than amedianInstead of using the median ratio or the average ratio from Marks & United States of America
Nunez for Table 4.16B, you should use the ratio of the average AE
related EF to average LVAE EF. This method would result in a ratioof 1.15 for Legacy PFPB and 1.64 for Modern. This would be more
representative of the data than a median of the ratios or an average ofthe ratios. This would result in an overestimate for many individual
smelters but result in the correct total for all smelters combined.

5690

3

4

1211

1212

5692

3

4

1211

1212

To remove an outlier and instead use the median for the
LVAE/HAVE value in Table 4.16B, justification needs to be given
for why the value is being discounted, i.e. why is it nonrepresentative? Outliers should be kept unless there is reason tobelieve that it is not representative (and if so, the reason for theirremoval explained). One possible explanation provided for theseoutliers exists in Dion et Al 2018a. In that paper, it is explained thathigh ratios exist at some facilities due to large decreases in HVAE
emissions. As these lower HVAE emissions (or similar data) were
presumably used when determining the EFs for HVAEs, thecorrespondingly high ratios should not removed here

6288

3

4

1218

1230

Australia
A question in relation to equation 4.27c - if an emission ratio is
applied to HVAE emissions to derive LVAE emissions, is it necessary
to multiply the result by metal production (MP)? When this approachis taken - emissions seem implausibly high? I would suggest the term
Mp is not required in this equation

United States of America

Response

Authors notes

Noted

We have removed T2 ratio which differed in its approach so this is nolonger an issue.

Rejected

We considered this approach however the uncertainties for T2 would
still be >T1 due to the inclusion of the HVAE element in its calculationand the range of the underlying data.

Noted

We have removed T2 ratios and this is no longer an issue. We have notremoved any 'outlier' data in the calculation of the Efs included.

Accepted

The reviewer's comment was correct. MP has been removed.

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5694

3

4

1233

1240

United States of America
In the decision tree, the decision diamond "Is there an automatic
HVAE termination strategy" should be moved to immediately follow
the Start box. If the answer to the question is "no," the action
recommended is to calculate PFC emissions using the Tier 1 method,
regardless of whether process data are available or whether the
category is key. A "yes" answer would lead to the rest of the decisiontree.

Rejected

It is important to allow for these cell technologies the possibility to use
Tier 3 if the data is available.

5696

3

4

1233

1240

Accepted withmodification

An additionnal box was added in the decision tree to account for this
scenario.

5698

3

4

1235

1236

In the decision tree, consider replacing the question "Is there an
United States of America
automatic HVAE termination strategy" with "Do facility tracking
systems for anode effects detect and record them as soon as the cellvoltage exceeds 8 volts?" The discussion in Marks & Nunez, 2018a(Updated Factors for Calculating PfC Emissions from Primary
Aluminum Production) implies that it is a "no" response to the latterquestion rather than the former that makes use of a Tier 1 approachnecessary for PFPBmw.
The Decision Tree (Figure 4.12) currently allows you to by-passes the United States of America
question "Is this a key category" if process data is available but stillends up possibly recommending a Tier 1 method. A Tier 1 method isinconsistent with good practice for key categories but would bepossible with this decision tree.

Accepted

Decision tree was modified to take this into consideration.

5700

3

4

1247

1248

The values listed in Table 4.15 for CF4 from HVAE are the values
listed in Marks & Nunez 2018 as the TOTAL CF4 from LVAE and
HVAEs. Since Table 4.15 separates out LVAEs from HVAEs, thevalues for HVAEs should be from column E in Marks & Nunez or
you are double counting LVAEs.

United States of America

Accepted

Changed in table

5702

3

4

1247

1248

The value for C2F6 for PFPB-MW seems low, as it's much lower than United States of America
the average C2F6/cF4 ratio of 0.073 (Marks & Nunez 2018)

Rejected

Tier 1 C2F6-HVAE emission factor value of 0.005 kg C2F6/t Al in
Table 4.15 for PFPB_MW is correct. The 0.073 value quoted by thereviewer refers to the Tier 2 coefficient/ ratio of C2F6/CF4 in the Marks& Nunez 2018 publication, not to Tier 1 emission factors here

5706

3

4

1247

1248

In the source paper for Table 4.15 (Marks & Nunez 2018a), the paper United States of America
authors observe that performance improvements and technology
changes have made the Tier 1 default emission factors in the 2006
IPCC Guidelines out of date. The authors of section 4.4 apparently
rely on this conclusion in their decision to replace the 2006 Tier 1
defaults with those published in the source paper. Rather thanreplacing the 2006 factors, however, the authors should provide
guidance on how to use them, along with the updated factors, toestimate emissions over the entire time series (e.g., back to 1990). For
example, the authors could recommend that inventory compilers
apply the new factors after 2010 and the old factors from 1990-2005,
linearly interpolating between 2005 and 2010. The Refinement must
provide guidance for estimating emissions over the entire time series.

Accepted withmodification

A specific table was added to the refinements in order to specify which
coefficient to use, for which periods.

5708

3

4

1247

1248

United States of America
In Table 4.15, in the first column under the headings "HVAE" and"CF4," default CF4 EFs are provided for HVAE. These factors are thesame as the values shown in column C of Table 1 in the source paper(Marks & Nunez 2018a). However, the source paper indicates that thevalues in column C represent total emissions from both HVAE and
LVAE (page 1520, second column). The source paper includes adifferent column for HVAE-only emission factors, column E. The
section authors should ensure they are drawing from the correctcolumn of the source paper.

Accepted

Changed in table

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5704

3

4

1247

1284

United States of America
In Tables 4.15, 4.16, and 4.16B, the source paper is identified as
Marks & Nunez 2018B, which is identified in the endnotes as "New
Algorithm for Calculating CF4 Emissions from High Voltage Anode
Effects" in: Light Metals, Phoenix. For all three tables, the correctsource paper appears to be Marks & Nunez 2018A, "Updated Factors
for Calculating PFC Emissions from Primary Aluminum Production."
In: Light Metals, Phoenix, AZ.

Accepted

There was indeed an inversion in the reference.

5710

3

4

1254

1255

The values in Table 4.16 for PFPB-L do not match the Marks &Nunez 2018 paper. If a different source was used, it should be noted

Accepted

Changed in table

5712

3

4

1254

1255

In the source paper for Table 4.16 (Marks & Nunez 2018a), the paper United States of America
authors observe that technology changes have made the Tier 2 default
slope factors in the 2006 IPCC Guidelines out of date. The authors ofsection 4.4 apparently rely on this conclusion in their decision to
replace the 2006 Tier 2 defaults with those published in the source
paper. Rather than replacing the 2006 factors, however, the authors
should provide guidance on how to use them, along with the updated
factors, to estimate emissions over the entire time series (e.g., back to1990). For example, the authors could recommend that inventory
compilers apply the new factors after 2010 and the old factors from1990-2005, linearly interpolating between 2005 and 2010. The
Refinement must provide guidance for estimating emissions over theentire time series.

Accepted withmodification

A specific table was added to the refinements in order to specify which
coefficient to use, for which periods.

5714

3

4

1254

1255

In Table 4.16, the first value in the column (SCcf4 for PFPBL), 0.127, United States of America
does not match the corresponding value in the source paper (Marks &Nunez 2018a, Table 3), 0.111. Instead, it appears to be a simple
average of the 2006 IPCC slope factor of 0.143 and the 0.111 value
provided in Marks & Nunez. This may be appropriate if the difference
between the 0.143 2006 slope factor and the 0.111 value simply
reflects different sample sets rather than a trend. However, if thedifference between the slope factors reflects a trend (as seems likely
given the technological changes cited in Marks & Nunez), then 0.111
factor should be adopted for some set of recent years while the 0.127
factor should be retained for some set of earlier years.

Accepted

0.111 value adopted in table to reflect latest data

5716

3

4

1261

1262

United States of America
In Table 4.16A, the source paper is identified as Marks & Nunez
2018A, "Updated Factors for Calculating PFC Emissions fromPrimary Aluminum Production," in: Light Metals, Phoenix, AZ. The
correct source paper appears to be Marks & Nunez 2018B, which is
identified in the endnotes as "New Algorithm for Calculating CF4Emissions from High Voltage Anode Effects" in: Light Metals,
Phoenix.

Accepted

Citations have been corrected

5718

3

4

1261

1270

Table 4.16A needs to be expanded to include the uncertainties
associated with the constants K1 and K2 for the three categories ofanode effect duration. Uncertainties should also be provided for theconstants C1 through C4 in Equation 4.27D.

United States of America

Accepted

The uncertainties associated to the Tier 2b methodologies were added tothe document.

5720

3

4

1283

1284

It seems like this should reference Marks & Nunez 2018A instead ofMarks & Nunez 2018B. I think there are multiple instances wherethese references are mixed up.

United States of America

Accepted

There was indeed an inversion in the reference.

United States of America

Comment ID Volume Chapter From line To line
5722

3

4

1283

1284

5724

3

4

1294

1312

5726

3

4

1313

1314

5728

3

4

1317

5730

3

4

5732

3

5734

Comment

Country

Table 4.16B includes median LVAE/HVAE values for the PFPBL and United States of America
PFPBM technologies rather than average values for thesetechnologies. This is a very consequential decision as the medianvalue for PFPBL is 7 times smaller than the average value, while themedian value for PFPBM is 5 times smaller than the average value(Marks & Nunez, 2018a). The average should be used unless the
sample populations of smelters for each technology differ
fundamentally from the general populations of smelters for eachtechnology.
This section needs to be expanded to address the new Tier 2b and 3b United States of America
methods, which require process data on the duration of each HVAE
and on either line current or production for cells where HVAEs occur.

Response

Authors notes

Noted

We have removed T2 - no longer an issue.

Accepted

Activity data section has been updated to describe data requirements for
HVAE, LVAE and cell start-up emissions.

Given the inclusion of a new source in this section of the Refinement United States of America(LVAE emissions), it would be prudent and reasonable to include one
or two sentences in the "Completeness" discussion advising thatinventory compilers account for this source. Even if edits to theCompleteness discussion were not identified in the original TOC,
they are easily justified as edits to maintain consistency with the otherparts of the aluminum section.

Accepted"Completeness" discussion for Aluminium has been updated, adressing
the addition of LVAE emissions and those from cell start-ups improveoverall completeness for total PFC emissions.

1332

United States of America
This guidance should also address how to ensure time seriesconsistency while transitioning from using the current Tier 2 and Tier
3 slope factor approaches (renamed Tier 2a and Tier 3a in the SOD)
to the new Tier 2b and Tier 3b approaches based on anode effectduration. Using the methods in parallel for three years, as
recommended for the overvoltage and slope methods in lines 1333
through 1338, may be a good solution.

Accepted withmodification

There was not any clear solution suggestion but it was refered to thesimilar "parallel" approach to ensure consistency.

1329

1332

This guidance to use the Tier 2 slope factors from the 2006
Guidelines through 2018 should be emphasized by also including it
above Table 4.16, and by expanding Table 4.16 to include columns
for the slope factors from the 2006 Guidelines, along with the years
for which they should be used (1990-2018).

United States of America

Accepted withmodification

A specific table was added to the refinements in order to specify which
coefficient to use, for which periods.

4

1333

1338

3

4

1341

1345

5736

3

4

1347

1351

5738

3

4

1356

1358

The suggestion to use the Tier 3 overvoltage and slope models inUnited States of America
parallel for three years is a good one.
Suggest including "alumina feeding strategy" in the list of factors that United States of America
can affect the applicability of Tier 3 slope factors to previous or later
years.
Recommend referencing Volume 1, Chapter 5 guidance on time series United States of America
consistency, as well.
United States of America
The guidance "to backcast the LVAE PFC emissions, for national
inventories, by using the respective Tier 2 coefficient specific to eachcategory up to 2007" is unclear. Is the advice to estimate pastemissions back to 2007, e.g., between the current inventory year and2007? If so, recommend changing "up to 2007" to "back to 2007."

Noted
Accepted

Added alumina feed control strategy as another factor that affects
application of past Tier 3 coefficients or emission factors

Accepted

Added reference to Vol 1, Chapter 5 at start of section 4.4.2.7

Accepted

A specific table was added to the refinements in order to specify which
coefficient to use, for which periods.

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

5740

3

4

1363

1369

This discussion states that, due to the high uncertainty of LVAE PFC United States of America
emissions from individual smelters, the Tier 2 approach should not be
used to backcast LVAE emissions from a small number of smelters.
However, the same logic could be used to argue against using the Tier
2 approach to estimate LVAE emissions for the current inventory year
from a small number of smelters. It is always the case that, whendefault emission factors are based on data showing high variability,
the resultant uncertainties in the emissions of the population will behigher (in relative terms) for smaller populations than for larger
populations. The uncertainty associated with the estimate for smaller
populations is nevertheless preferable to the underestimate that would
result from not making the estimate at all. If the authors mean that theTier 2 LVAE/HVAE ratios may not be applicable to all years because
the underlying measurements reflect significant process andtechnology changes that have occurred since 1990, then the authors
should suggest an alternative to applying the Tier 2 LVAE/HVAE
ratios to years before 2007, e.g., using Tier 1 LVAE EFs. Ignoring
LVAE emissions for years before 2007 will lead to incomplete,inconsistent estimates.

Rejected

It was proposed to neglect LVAE prior to 2006 because the process
conditions that favors LVAE has changed over time and it is very
unlikely that the level of LVAE emissions were as high as 2010 and up.
In addition, the IAI AE survey demonstrate a clear downward trend inreported HVAE up to the year 2010, this corroborates the fact that
LVAE were not as important in comparison to the total PFC emissions
from a facility, thus LVAE were most probably immaterial. Finally,
there is no data available to reasonably determine a pre-2006 LVAE EF,
thus it is preferable to ignore those emissions than to blindly guess anumber.

5742

3

4

1365

1369

Instead of omitting LVAE emissions in historical data, it would be
preferable to take a conservative approach for accounting for theseemissions. Perhaps it would be appropriate to use one of the lower
LVAE/HVAE ratios as a default for pre-2007 data?

United States of America

Rejected

5744

3

4

1365

1369

Accepted

5746

3

4

1381

1399

5748

3

4

1400

1418

5750

3

4

1419

1420

5752

3

4

1489

1490

Can you clarify what you mean by 'historical data'? Do you mean pre- United States of America
2007? Earlier on line 1358, the guidance encouraged national
inventories to account for LVAE PFC emissions 'up to 2007' (Iassume you mean back to 2007) and for pre-2006, not to calculate
LVAE emissions, but this is unclear.
Should this guidance, which addresses the uncertainties of EFs forUnited States of America
CO2, be grayed out? CO2 emission factors are not being addressed in
the Refinement.
This discussion should address the uncertainties associated with use United States of Americaof the 2b and 3b methods relative to the 2a and 3a methods.
This sentence is unclear. Are the authors trying to say that theUnited States of America
absolute uncertainty associated with LVAE emissions based on the
Tier 2/3 methods is higher than that associated with HAVE
emissions? Or are they referring to the relative uncertainty?
To address the data requirements of the Tier 2b and 3b methods,
United States of America
Table 4.17 needs to be expanded to include separate columns forTiers 2a, 2b, 3a, and 3b; and rows for the duration of each anodeeffect, the line current for each anode effect, and the daily aluminumproduction of cells that experience anode effects.

It was proposed to neglect LVAE prior to 2006 because the process
conditions that favors LVAE has changed over time and it is very
unlikely that the level of LVAE emissions were as high as 2010 and up.
In addition, the IAI AE survey demonstrate a clear downward trend inreported HVAE up to the year 2010, this corroborates the fact that
LVAE were not as important in comparison to the total PFC emissions
from a facility, thus LVAE were most probably immaterial. Finally,
there is no data available to reasonably determine a pre-2006 LVAE EF,
thus it is preferable to ignore those emissions than to blindly guess anumber.
The text was modified and a table was added to clarify time-consistency
concerns.

Accepted

Section greyed out

Accepted

The uncertainties associated to the Tier 2b methodologies were added tothe document.
Changed wording in text to clarify

Accepted withmodification

Accepted

Table 4.17 has been updated to include all data requirements for new
methods in 2019 Refinements

Comment ID Volume Chapter From line To line

Comment

Country

Authors notes
Cement production is not a part of alumina production. It is external
process that use belite mud as a raw material. So Cement production
shall use the appropriate methodology for cement production
considering carbonate content in raw materials. The primary intention touse belite mud in cement production is waste utilization to reduce
environmental impact but not for GHG emissions reduction. The
appropriate text has been changed to give more clear explanation about
by-product process CO2 emissions calculation.

The proposed Tier3 approach is very complicated and requires a lot of Russian Federation
additional data and technological parameters. It seems to be very timeand resource consuming. Implementation of Tier3 methodology may
be very difficult or impossible for inventory compilers. (It is stated,that frequent (annual?) calculations of emissions could beburdensome even for some plants (line 1733)). However, in theabsence of Tier2 approach it will be mandatory for national inventory
compilers to use Tier3 in case alumina production is a key category ofnational inventory. To solve this problem a Tier2 methodology should
be developed. The Tier 2 methodology may be similar tothe Tier1 butusing national or plant specific Emission Factors. Emission Factors
for Tier 2 methodology may not be provided in the text, they can be
developed by Parties or obtained (in future) from the IPCC EFDB
taking into account national circumstances of Parties.

Accepted

A Tier 2 method shall be the same like Tier 1 method but country
specific emission factors shall be used instead of World-wide emissions
factors.

The statement that Tier 1 method is based on the site specific data is Russian Federation
contrdictorary to the description of this methodology below. In fact,
the proposed Tier 1 is based on the country specific activity data andthe default EFs. As it formulated in the Terms of Reference for
production of a Methodology Report to refine the 2006 IPCC
Guidelines for National Greenhouse Gas Inventories: "Tier 1
approaches are simple methods that can be applied by all countries inall circumstances." Tier1 approach cannot be based on site specificinformation.
Russian Federation
Taking into account that in the table 4.17A (lines 1860 -1861) two
different Emission Factors are provided for two different
technologies, the equation 4.27e (lines 1675 - 1677) should be
rewrited as follows: CO2 Emissions = MAl2O3 * Sbs *EFbs+MAl2O3 *Snp*EFnp +MLime*EFLime, here Sbs - mass fraction ofalumina produced by Bayer-sintering (BSS and BSP) technology,
EFbs - Emission Factor for Bayer-sintering (BSS and BSP)
technology, Snp - mass fraction of alumina produced by Nepheline sintering process (NP), EFnp - Emission Factor for Nepheline sintering process (NP). The other variables of the equation are thesame as in lines 1680 - 1687.
In table 4.28, using 'kg/tonne RE Metal' instead of the current 'g/tonne United States of America
RE metal' would be more consistent and comparable with thealuminum section of the chapter.

Rejected

Because each country (one of three) has one or maximum two plans
operated with similar technology it is impossible to avoid usage of site
specific data for Tier 1 emissions factor calculation. If any other country
in future will apply one of the technology with sintering the Tier 1
coefficient can be applied.

Accepted

The Formula has been modified as it was porposed.

Rejected

To our understanding, there is no standard unit for emission factors
across the IPCC guidelines and there is no need to be consistent withaluminium. Other metal industries use t CO2/t metal, or g CO2/ t
production, etc. Use of kg/t metal units for PFC emission factors for
Rare Earths would result in many decimal places for C2F6 and C3F8 inparticular. Ultimately, the output is in kg PFC emisisons, which isconsistent wtih aluminium.

3

4

1563

1565

There is no CO2 emission from soda ash and potash production.
These two by-products reduce CO2 emission from alumina
production. It is not also clear how to split CO2 emissions between
alumina and cement production. Obviously, using of belite mud incement producing industry reduces CO2 emissions from cement
production. However, no methodology is provided to estimate thisCO2 emission reduction. This issue should be considered in the
Guidlines.

6778

3

4

1644

1645

6772

3

4

1663

1664

6774

3

4

1674

1687

5754

3

4

2371

2372

Russian Federation

Response
Noted

6776

Comment ID Volume Chapter From line To line
5756

3

4

2371

2372

Comment

Country

The EF for C2F8 for RE alloys using the ratio from Cai 2018 of
United States of America
0.03/109.43 *the CF4 EF of 146.1 results in a value of 0.04, not 0.05.

Response
Rejected

Authors notes
The C3F8 emission factor of 0.05 was calculated using original raw data
values from the Cai et al. 2018 study, rather than rounded values foundpaper itself, in order to minimise rounding errors.
Using C3F8/CF4 ratio = 0.000318 (instead of just 0.00031), when
multiplied by EF_CF4 of 146.1, this gives EF_C3F8 of 0.0465 g/t Al,
which was then rounded up to 0.05 g/t Al, to the nearest 2 decimal
places. In any case, the scale of C3F8 emissions to Total CO2e PFC
emissions is <0.05%, so there is effectively no difference between an
EF_C3F8 value of 0.05 vs. 0.04.

5758

3

4

2371

6916

3

6

5

884

3

6

215

6488

3

6

215

886

3

6

241

6490

3

6

241

5760

3

6

241

888

3

6

890

3

6

892

3

6

252

6492

3

6

252

894

3

6

896

3

6

2372

5

In Cai et al. 2018 it is noted that automated feeding resulted in a 40% United States of America
reduction in the measured emission factor from 2014. Based on thisinformation, it seems like it would be better to adopt similarterminology to the Aluminum chapter and have an emission factor
technologies that have the automated feeding and a separate one forthose which do not. Cai presents three different classes: lowamperage technology, high amperage technology and high amperagewith automatic control technology. If there is not enough data for all
three categories, it still is likely to be appropriate to separate thosethat have automatic control technology from those that do not,especially as the current data set is not presented as a globally
representative data set in terms of technology types. Another option
would be to weight the EF data to resemble the global percentage oftons of RE manufactured using automatic control technology to makeit more representative. The guidelines state that "many rare earth
technologies currently do not use automated computer control
systems to detect anode effects" (lines 2265-2266) but much of theCai 2018 data used to develop EFs is from a facility that has
automated control systems.
Republic of Korea
Why are these phrases of "Parts in brackets – comments from
Authors/issues that may be refined" in Chapter 6 and "Bracketed text–
characterization of guidance as new, updated, and/or elaborated" in
Chapter 7 different? It would be better to unify the patterns if there
are no special reasons.
Chemical formula format of “NF3”, “C4F6”
Thailand

Rejected

There is insufficient emissions factor data to support adoption of
separate technology classes within the rare earths guidance.
Furthermore, the 'automation upgrades' in the Cai et al 2018 paper were
unclear and vague on details of what was implemented to achieve lower
emissions, that would then justify and enable a separate technology class
to be described.
However, further guidance has been added noting the potential forfurther automation and technology development to reduce PFC
emissions from rare earths production. In this case, it is good practice toemploy Tier 3 facility specific methodologies.

Accepted

The discussion of changes to each section or chapter has been
harmonized in the Final Draft.

Accepted

Change made on final draft

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

Chemical formula format of “NF3”, “C3F8”

ThailandAccepted

Change made on final draft

243

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft244

It is unclear what this sentence means. It seems to be missing words. United States of America

Accepted

Change made on final draft

242

Chemical formula format of “NF3”, “C3F8”, “N2O”

ThailandAccepted

Change made on final draft

243

Chemical formula format of “N2O”

ThailandAccepted

Change made on final draft

215

Chemical formula format of “N2O”

ThailandAccepted

Change made on final draft

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

253

Chemical formula format of “N2O”

ThailandAccepted

Change made on final draft

260

Chemical formula format in “BOX 6.1”

ThailandAccepted

Change made on final draft255

Comment ID Volume Chapter From line To line

Comment

Country

Response

Authors notes

6494

3

6

260

260

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6496

3

6

263

263

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6498

3

6

267

268

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6500

3

6

272

272

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6502

3

6

274

274

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

898

3

6

377

Chemical formula format of “N2O”

ThailandAccepted

Change made on final draft

6504

3

6

461

461

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6506

3

6

525

527

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6508

3

6

530

530

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

5762

3

6

594

717

The addition of Tier 2C - process type and wafer size specificemission factors - is a significant improvement over the previous
guidelines. However, it would be useful to specify if the "Adapting
Tier 2 Methods to Account for Technological Change" section ismeant to modify Tier 2C, if applicable, or could be used in
combination with any Tier 2 method, which is implied.

United States of America

NotedThis was clarified in the final draft.

6510

3

6

633

635

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

6512

3

6

638

638

Subscript the numbers in all of the chemical formulae

United Kingdom (of GreatBritain and Northern Ireland)

Accepted

Change made on final draft

5764

3

6

695

700

In lines 695-700, facilities are given the option to use a default of 0.8 United States of America
for 1-U for new gases or process types, but the decision tree indicatesthat they should take measurements. It would be useful to provide
guidance for when the 0.8 default is acceptable (e.g. for low gas
consumption volumes of the new gas or like in the case of the new
substrate type described in lines 710-716, for the first year of use).

Accepted

Added a sentence saying that defaults of 0.8, 0.15 (for CF4) and 0.05
(for C2F6) are acceptable when gas usage for the new GHG and process
type combination is below 1% of facility-wide gas usage.

5766

3

6

696

697

The caveat "and when the use of the input gas(es) does not result in
United States of America
the formation of greenhouse gases as process byproducts (e.g.
formation of CF4 from F2, COF2 chamber cleaning or from CF3Ibased etch processes)" should be deleted. The possibility of byproductgeneration from low-GWP input gases is adequately addressed by theassumption that 20% of the gas mass is transformed into CF4 andC2F6 byproducts.

Accepted withmodification

Removed caveat and updated the option for using a default of (1-U)=0.8
and BCF4=0.15 and BC2F6=0.5 in text.

6514

3

6

697

697

Subscript the numbers in all of the chemical formulae

Accepted

Change made on final draft

United Kingdom (of GreatBritain and Northern Ireland)Comment ID Volume Chapter From line To line
5768

3

6

718

1117

5770

3

6

720

726

900

3

6

802

6516

3

6

1194

1194

6918

3

6

1217

1226

902

3

6

6920

3

7

83

7578

3

7

6518

3

7582

Comment

Country

United States of America
The refinement of the Tier 3 method (to the new Tier 3a), including
the addition of criteria for similarity among recipes, is a significant
improvement to the guidance, as is the addition of the Tier 3B method. These refined and additional methods will allow facilities todevelop emission factors that are more accurate for their facilities andallow them to more easily show reductions in the GHGs due tochanges in process conditions.
If Tier 3a uses the same equations as Tier 2c, then the equations
United States of America
referenced should be equations 6.10 to 6.13, not 6.7 to 6.10. (Seeboth line 721 and line 726).
ThailandMisuse label of the equation number.Change “EQUATION 6.13
(NEW)” in page 6.24, line 802 to “Equation 6.14 (NEW)” because
the number “6.13” already exit in page 6.20, line 657.
Subscript the numbers in all of the chemical formulae
United Kingdom (of GreatBritain and Northern Ireland)

Response

Authors notes

Noted

Accepted

Change made on final draft

Accepted

Change made on final draft

Accepted

See comment 6508

To reduce the uncertainty of estimation, the emission factors need tomove the decimal point of the left by changing the unit such as
0.00003kgCH2F2/kgSF6 -> 0.03kgkgCH2F2/tonSF6
Tier 3B Method use subscript “j” to represent the “stack system” inequations 6.14 and 6.15 but equations 6.16-6.18 use “s” to describe
the same notation. It may confuse the reader.Is it possible to use thesame notation for the same description in the same section?

Republic of Korea

Rejected

Does not reduce uncertainty to change the units.

Thailand

Noted

Addrssed in the final draft.

84

It wolud be better to add revised or newly added contents first (infront of introduction) like Chapter 6.

Republic of Korea

Noted

The refinement Final Drafts have been formatted in a manner consistent
with IPCC task-force recommendations, in order to highlight to users: (i)where text has been updated; (ii) where there is new guidance; and (iii)
where there has been no refinement.

190

191

Finland
Table 7.3B includes data only from Article 5 Parties. Please add
similar data from Non-Article 5 Parties because the share between
different sub-applications can vary considerably. Especially the shareof Commercial Refrigeration can be considerably higher in many
countries.

Accepted

7

292

292

Accepted

3

7

541

544

7580

3

7

566

623

6520

3

7

576

576

6922

3

8

5

5

The link to the HFC guidance sheets on the Ozone Secretariat website United Kingdom (of Great
doesn’t work. The Secretariat is building a new website and the link Britain and Northern Ireland)
will need to be updated.
FinlandPlease extend Table 7.9 to include more subcategories also in othercategories than Mobile A/C. If possible, the equipment types could
also be separated according to their power/capacity. In addition, wesuggest that an appendix would be created where examples fromdifferent countries could be gathered on the different
subcategories/equipment with the national/country-specific emission
factors.
The reported data according to Article 19 of Regulation (EC) No
Finland517/2014 (F-gas regulation) should be added as an example of a
useful data source for the inventory data for EU member states. The
data is accessible via the EU's F-gas Portal.
Suggest saying 'Countries that have ratified the Kigali amendment to United Kingdom (of Greatthe Montreal Protocol will have to report consumption and
Britain and Northern Ireland)
production data annually.'
Republic of Korea
There are no the phrase like "Parts in brackets – comments from
Authors/issues that may be refined" in Chapter 6 or "Bracketed text –characterization of guidance as new, updated, and/or elaborated" in
Chapter 7.

Accepted withmodification

It is difficult to find a common matrix for different equipment types indifferent regions. In order to provide the readers with more possibilities
than only table 7.9, we have included three tables in Appendix X
showing emissions factors from German, Californian and Japan studies.

Rejected

Data from the EU f-gas Portal is not publically availalbe.

Accepted withmodification

The sentence now specifies that consumption includes production,
import and export

Accepted

Change made on final draft

Comment ID Volume Chapter From line To line
6924

3

8

69

70

7584

3

8

444

484

5772

3

Appendix 1

7108

3

Cover page

9216

3

3

1397

1483

9218

3

6

525

530

5

Comment

Country

It wolud be better to add revised or newly added contents first (inRepublic of Korea
front of introduction) like Chapter 6.
Some estimates of the share of this emission source from the total F- Finland
gas emissions of a country could be presented in this chapter in orderto estimate whether this could be a key category in some countries.
When no default emission factors are available the inclusion of thisemission source to the inventory can be a very demanding task
bearing in mind the often very limited resources for the inventory
work in many countries. The description of the methodologicalframework needs to be kept in the appendix until default emission
factors become available.
United States of America
Does the IPCC plan to address reabsorption of CO2 throughcarbonation within the cement industry, which is previous discussed
in the 2006 IPCC Guidelines? This would require revision to Volume
3 Chapter 2, or perhaps adding discussion/methodology into an
appendix similar to Fluorinated Compounds Emissions from Textile,
Carpet, Leather and Paper

Response

Authors notes

Accepted

Change made on final draft

Rejected

The format for including this new source category to Chapter 8 was
discussed and agreed to with the IPCC Task Force Bureau. The
description of the methodological framework is already in the Appendix.

Noted

No action can be taken because comment is out of scope of 2019
Refinement. This was not included as part of IPCC refinement mandate.
The authors thank the reviewer for highlighting this issue, which wenote as potentially of interest for future IPCC research.

NorwayAccepted

The authors thank the reviewer for highlighting these new F-gas
observations. The electronics authors recognize PFTBA as a popularheat transfer fluid used in electronics manufacturing. Although thecompound's GWP and atmospheric lifetime have not been published in
the peer-reviewed scientific literature, research by the manufacturer, as
well as the compound's perfluorinated structure, indicate that it has avery long atmospheric lifetime and a 100-year GWP near 10,000.
Guidance on estimating emissions of this and other fluorinated liquids isprovided in Chapter 6 of the Refinement. Research into the othercompounds indicates that they are used in a variety of applications,some of which are addressed in the 2006 IPCC Guidelines. For example,
PFPHP is used in cosmetics and medical applications, whose emissionsof perfluorinated compounds are addressed in Volume 3, Section 8.3 ofthe 2006 Guidelines (Use of SF6 and PFCs in Other Products). The
authors will note the other substances as potentially of interest for future
IPCC research.

The method for estimating CO2 emissions from H2 production should Canada
be similar to that for CO2 from ammonia production (both use steam
methane reforming). The emission estimation method for ammonia
production includes a carbon oxidation factor (COF), but not thatmethod for H2 production. Suggest to include such factor in themethod for H2 production. The current method assumes 100%oxidation.
CanadaDoes the factor AB(i, CF4) assume that there is NF3 or F2 exhaust
formed with all types of process gas consumed? Or is this factor only
considered if NF3 or F2 is the process gas? Is there a summary ofAB(i, CF4) default values located somewhere in the document (Icould not find these values in Table 6.3 for a Tier 2A methodology)?
There are two default values provided in line 529 and 530 but I
cannot see where these values were referenced. There is anotherversion of this same statement as Note 6 of Figure 6.4 (lines 12531257). PLease clarify.

Rejected

It is not assumed to be 100% oxidation, but all other production
processes for hydrogen is accounted for in other sectors. Hence,
including them in the hydrogen sector would lead to double counting.

Noted

The authors clarified the procedure to account for CF4 formation within
abatement systems and introduced a new equation (6.6B to be relabeled
6.7) with an option to use default values for AB(i,CF4) as indicated in
the definition of equation 6.6B.

See our comment to Vol 1, Ch. 8, line 110-118.