Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories

NON -CO 2 E M I SS IONS FR OM
STA TIONARY C OM BUSTIONACKNOWLEDGEMENTS
This paper was written by Samir Amous (Tunisia) and reviewed by Gregg Marland (USA), Jim Zihang (China),
and Karen Treanton (IEA).

ABSTRACTIn parallel to CO2 emissions due to the Stationary Combustion, five major non-CO2 greenhouse gases are emitted
during the combustion process: CH4, N2O, NOx, CO, and NMVOCs. In addition, due to the sulphur content offossil fuels, significant quantities of SO2 are emitted during the combustion, and may influence the climate,although SO2 is not a greenhouse gas.
All these gases are addressed by the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories(IPCC Guidelines). The technical approach in estimating CO2 emissions is relatively simple and the accuracy
level high since the CO2 emission factors are mainly a function of the fuel properties, which are generally welladdressed by most countries. The non-CO2 emissions however are closely linked to a number of parameterswhich are specific to each combustion plant: the type of technology, the combustion process; operating andmaintenance conditions, the size and the vintage of the combustion equipment, the emission control policy, thefuel characteristics, etc.
The most accurate emission inventory of the non-CO2 emissions due to stationary combustion would betherefore to have all the necessary details regarding the specific emission factors (EF) and the activity data (AD)of each combustion plant in a given country.
While the unavailability of detailed data is a major obstacle that prevents countries from applying suchapproaches, it should be noted that the contribution of non-CO2 gases due to stationary combustion to thenational emission budgets is low, particularly for CH4 and N2O.
In estimating non-CO2 emissions, the most accurate result is obtained by:•

Using the best available data in the country and applying the national emission factors;•

Using the Tier 2 approach recommended by the IPCC Guidelines where the national activity data present
the level of details that fits into the IPCC suggested default emission factors;•

Using the Tier 1 approach recommended by the IPCC Guidelines where the level of detail of the national
activity data does not fit in the Tier 2 IPCC suggested default emission factors, and•Reporting transparently on assumptions that are considered when carrying out the calculations.

In addition, there is some room for improving the methodological approaches, in particular in relation to:•

The development of more appropriate emission factors. These might be defined for instance by using theclassification of the determining factors that were described above (e.g. classification according to
combustion conditions in Organisation for Economic Cooperation and Development (OECD) countries,
Countries with Economies in Transition, Developing Countries, etc.). This would eventually be achieved
through relevant research and data collection processes at the international level, and•The development of more appropriate default emission factors for biomass combustion, particularly in small
devices, which are in use in the developing countries.

Non-CO2 Emissions from Stationary Combustion

41

Background Paper

1

INTRODUCTION

1.1

Nature, magnitude, and distribution of source

Different non-CO2 gases are emitted through energy combustion processes from stationary sources. The Revised
1996 IPCC Guidelines for National Greenhouse Inventories (IPCC Guidelines) include calculations for mainly
six non-CO2 gases: methane (CH4), nitrous oxide (NO2), nitrogen oxides (NOX), carbon monoxide (CO),non-methane volatile organic compounds (NMVOCs) and sulphur oxide (SO2)
On the other hand, five major end-use combustion sources are considered:•

Energy Industries (i.e. electricity generation, charcoal production, etc.);•

Manufacturing industries (including electricity self-generation);•

Commercial/institutional sector;•

Residential sector, and•Stationary Agriculture/Forestry/Fishery sources.

Unlike the CO2, the emission estimates related to these gases require much more detailed information regarding
the specific emission factors and activity data.
Different greenhouse gases addressed by the IPCC Guidelines
CH4
CH4 is emitted in limited quantities from fuel combustion due to incomplete combustion of hydrocarbon in fuels.
The emission of methane is dependant on the temperature in the boilers. In large combustion facilities andindustrial applications, the emission rates are very low, while these emission rates are much higher in smaller
applications such as residential (i.e. small stoves, open burning).
The contribution of the stationary combustion to total CH4 emissions is generally minor and the uncertainty is
medium to high. Therefore according to the IPCC Guidelines, the use of the simplified Tier 1 Approach consistsof an aggregated fuel/sources split. However, it might be necessary to pay greater attention to the methodologicalapproach addressing the biomass use, given the significant contribution of the biomass combustion to CH4emissions in the countries with large biomass consumption, particularly in developing countries.
N 2O
N2O is emitted directly from fuel combustion. The emission of N2O is dependant on the temperature in the
boilers. The emission rates are the highest when the combustion temperature ranges from 800K to 1200K, while
the emissions are negligible below 800K and over 1200K. The mechanisms of N2O chemistry is relatively wellunderstood though the experimental data are limited.
Like CH4, the contribution of the stationary combustion to total N2O emissions is minor and the uncertainty ishigh. In addition, reliable emission factors are not yet available for all sources Therefore the IPCC Guidelines
allow the use of a very simplified Tier 1 approach that considers an aggregated fuel/sources split. N2O emission
estimates due to biomass uses are poorly documented and the emission factors are uncertain.
NOx
Nitrogen Oxides (NOx1) are indirect greenhouse gases. Fuel combustion activities are the most significant
anthropogenic sources of NOx, in which energy industries and mobile sources are the most important. Two
different formation mechanisms of NOx can be distinguished:•

Formation of “fuel NO” from the conversion of chemically bound nitrogen in the fuel, and•Formation of “thermal NO” from the fixation of the atmospheric nitrogen in the combustion process.

The majority of NOx emitted from coal (80-90%) is formed from fuel nitrogen. Excess air and high temperatures,
which depend on the boiler type and technological operations encourage the formation of NOx.
1

In the IPCC Guidelines the NOx emissions (NO+NO2) from fossil fuels combustion are expressed on a fullmolecular basis assuming that all NOx emissions are emitted as NO2.

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Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories

For oil, less than 50% of the NOx emitted is formed from fuel nitrogen, while the totality of NOx emitted fromgas is formed from thermal nitrogen.
The NOx emission factors that are estimated should be adjusted according to the emission control used in the
country. The IPCC Guidelines provide some default reduction efficiencies for coal-fired installations when
information related to these equipment are not available in the country.
CO
Carbon Monoxide (CO) is an indirect greenhouse gas. While the motor vehicles are the most significant fuelcombustion sources of CO, the small residential combustion equipment are also important.
The formation process of CO is directly influenced by usage patterns, technology type and size, vintage,
maintenance and operation of technology. It should be noted that the emission rates may vary by several ordersof magnitude and are particularly highly affected by the operating and maintenance conditions, particularly inthe case of older or smaller equipment. The small woodstove devices that are widely used in the developingworld have a particular high emitting potential (and variable according to the region and conditions of use) due
to the inefficient combustion.
Overall, the stationary combustion generally contributes to a small but still significant portions of national CO
emissions.
NMVOCsThe Non-Methane Volatile Organic Compounds (NMVOCs2) are indirect greenhouse gases. The NMVOCs are a
result of an incomplete combustion and are directly influenced by usage patterns, technology type and size,
vintage, maintenance and operation of technology. It should be noted that the emission rates may vary by several
orders of magnitude as a function of the operating and maintenance conditions, particularly in the case of older
or smaller equipment. The emissions are generally very low for larger combustion plants where combustion
process is more efficient.
While the mobile sources are the most significant fuel combustion sources of NMVOCs, the small residential
combustion devices, particularly those using biomass, are also important. The small woodstove devices that are
widely used in the developing world have a particular high emitting potential (and vary according to the region
and conditions of use) due to the inefficient combustion devices.

1.2

Sources of emissions associated with stationary
combustion

The IPCC Guidelines consider five main sources (or sectors) of Stationary Combustion. The minimum datarequirement is therefore to have a detailed energy consumption picture presenting the energy consumption by
sector and by energy product.
Energy industries
This sector includes all combustion sources, whose primary activity is to exploit, treat and transform primaryenergy products, and to supply secondary energy products. These include:•

Public Electricity and Heat Production (combined or not);•Petroleum Refining;•

Manufacture of Solid Fuels (such as production of coke, brown coal briquettes, charcoal, etc.), and•Other energy industries (combustion arising during coal-mining and oil and gas extraction activities, etc.).

Manufacturing industries and construction
This sector includes all combustion arising in the manufacturing industries including combustion for thegeneration of electricity and heat that occurs at the level of industrial units. Emissions due to electricity
self-generation should be assigned to the sectors where they occurred. These should also be separated from theemissions that are generated in the combustion plants, and where possible, the specific emissions due toelectricity and heat generation should be reported separately.

2

All hydrocarbon compounds excluding those inventoried under the Montreal Protocol are considered as
NMVOCs. These gases are volatile under ambient air and expresses as mass units.

Non-CO2 Emissions from Stationary Combustion

43

Background Paper

Emissions from Manufacturing Industries should be specified by sub-sectors that correspond to the International
ISIC Classification. The IPCC Guidelines suggest the following sub-sectors:•

Iron and Steel;•

Non-Ferrous Metal;•

Chemicals;•

Pulp, Paper and Print;•

Food Processing, Beverages and Tobacco, and•Other industries.

A particular issue related to the combustion in coke ovens within the Iron and Steel industry, which IPCC
Guidelines recommend to report under Energy Industries (Volume I - Reporting Instructions, p.1.4) needs to beclarified.
Other sectors
These include three main emission sources:•

Emissions due to the combustion in Commercial and Institutional Buildings;•

Emissions due to the combustion in household devices, and•Emissions due to stationary combustion in Agriculture and Forestry sectors.

1.3

Current state of inventory methodologies

The IPCC Guidelines describe two approaches in estimating non-CO2 emissions from Stationary Combustion:
Tier 1 and Tier 2. However, these approaches are based on a similar calculating principle:
Emissioni = Σ (EFab ● Activityab)
Where:i:

The concerned gas (CH4, N2O, etc.)

EF:

Emission Factor (kg/TJ)

Activity:

Energy input (TJ)a:

Fuel Type (or energy product)b:

Sector Activity

Tier 1 Approach
The Tier 1 approach is used because of the limited availability of the national activity data and emission factors.
Therefore, the calculation method does not take into account the combustion technology and conditions underwhich the fuels are consumed.
The IPCC Guidelines suggest a specific table for each gas, presenting the aggregated EF (by source sector andby group of energy product3) that could be utilized under the Tier 1 approach. This table was compiled using
different international sources:•

CORINAIR90 database;•

CORINAIR94 default emission factors;•

The EDGAR version 2.0 database;•

National Communications to FCCC;•

Berdowski and 1993a and 1993b;•

Radian Corporation, and•

USEPA.

3

E.g. coal, natural gas, oil, etc. Refer to ANNEX 1 attached to this paper.

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Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories

Tier 2 Approach
The Tier 2 approach implies a wider degree of refinement. The use of this approach is recommended when
detailed and accurate activity data on the technology contribution within a given emitting source are available. In
addition, the corresponding emission factors should be available or easily derived (e.g. by using the default
information provided by the IPCC Guidelines), assuming an acceptable knowledge of the combustion
technologies and conditions under which the fuel is consumed.
The Tier 2 approach focuses on the combustion of all commercial fuels. It also covers the biomass that is
generally traded commercially and used in large combustion plants, while the biomass used in small residential
devices is not considered by the IPCC default emission factors.
Special considerations on Biomass sources
The IPCC Guidelines provide some rough guidance for estimating non-CO2 emissions from biomass.
In the Tier 1 approach, some rough default emission factors are presented. The approach that was used inestimating these emission factors (EF) is not described by the IPCC Guidelines. Moreover, the figures are highly
aggregated. For example, the EF related to wood and other biomass and waste are similar. In addition, the IPCC
Guidelines only differentiate between the large combustion plants (Energy Industries, Manufacturing Industries
and Construction) and the smaller combustion equipment (commercial, residential, agriculture). The various
combustion conditions of the small equipment, which are the major bio-fuel consuming devices in thedeveloping world, would need further research and evaluation.
In the Tier 2 approach, the default emission factors are again provided only for large combustion plants. The
carbon emission rates, and hence the non-CO2 emission rates of each biomass type are directly influenced by thefollowing determining parameters:•

The moisture content;•

The net calorific value;•

The carbon fraction of each bio-fuel type, and•The combustion efficiencies.

The good practice in addressing this emission module is to use the national data regarding these parameters.
However, the IPCC Guidelines provide default moisture content and net calorific values that could be used incase of unavailability of these data.
In addition, the IPCC Guidelines provide default carbonization efficiencies (6 kg of wood for 1 kg of charcoal),
default carbon content that could be considered for charcoal, as well as the default non-CO2 emission factors(Table 1).
TABLE 1DEFAULT NON-CO2 EMISSION FACTORS FOR CHARCOAL PRODUCTION (KG/TJ)
Default Emission Factor(kg/TJ of Wood input)

Default Emission Factor(kg/TJ of charcoal produced)

CH4

300

1000

N2O

N/A

N/A

NOx

5

10

CO

2000

7000

NMVOCs600

1700

Source: Table 1-14 – Vol. 3 - IPCC Guidelines, 1996.

2
2.1

METHODOLOGICAL ISSUES
Selection of good practice methods

The IPCC Guidelines provide some explanation on the approach to be used when undertaking non-CO2
calculations from stationary combustion equipment.

Non-CO2 Emissions from Stationary Combustion45

Background Paper

When actual non-CO2 emissions from stationary sources are not available, it is possible to use the Tier 2
approach, which provides a satisfactory level of accuracy, and uses three distinct sets of data assumptions:•

Emission Factors;•

Energy Activities, and•Relative share of technologies in each of the main energy activities, which should be available (bottom-up:
actual data detailed by individual source), or might be derived at national level (top-down: statisticalsampling, engineering judgment, etc.).

The IPCC Guidelines recommends six main steps to carry out the inventory calculations:•

Determine the source and form of the best available energy activity data with the highest level ofdesegregation. The good practice is to collect the national consolidated energy data, which are generally
adequately established at national levels, while the international ones may not be sufficiently accurate or are
based on rough estimates;•

Determine the main categories of emission factors that fit into the national energy system;•

Compile the best available emission factors, preferably from national sources. Where national sources are
not available, the selected EF should to some extent, have a minimum consistency with the technologicaland operating conditions of the country, and take the pollution control regulations that are in place in the
country, into account;•

Identify the technology categories to be used in the national inventory;•

Develop estimates of non-CO2 emissions (the six considered gases for each of the main sources), and•Sum the individual calculated GHG emission estimates.

Ultimately, the IPCC Guidelines recommend the use of Tier 1 approach in case of important gaps on activity
data or inadequate emission factors.

2.2

Emission factors

Unlike the CO2 emissions where emission rates are linked to almost solely the fuel properties, the non-CO2
emission factors are mostly influenced by various parameters that are specific to each country, and also to thespecific conditions of each combustion equipment or plant viz:•

The fuel characteristics;•

The type of technology;•

The combustion, operating and maintenance conditions;•

The size and the vintage, and•The emission control policy.

Therefore, the determination of the emission factors is a crucial issue for the quality, completeness, andconsistency of the inventory results.
The best approach is therefore to use the actual emission rates, or at least the most specific emission factors
available in each country. However, since it is not possible to find a full set of specific EF in each country,
particularly in the developing ones, the IPCC Guidelines suggest a set of default EF in order to improve thecompleteness of the inventory work.
Tier 1In many countries, the difficulties of deriving country-specific emission factors are combined with data
availability constraints that prevent applying the default EF that are derived from other countries or internationaldata, such as those presented by CORINAIR.
In order to overcome this barrier, the IPCC Guidelines provide an aggregated EF table for each of the non-CO2
gases. These tables4 present emission factors in terms of kg/TJ according to the sectoral sources of emissions(Energy industries, Manufacturing Industries, etc.) and the Energy Product (Oil, Gas, etc.).

4

Refer to ANNEX 1 attached to this paper.

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Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories

It should be noted that the EF tables related to non-CO2 emission factors represent very aggregated figures,
whose estimating approach is not described by the IPCC Guidelines. For example, in many instances, the IPCC
Guidelines do not discriminate the EF among the main sources (Energy Industries, Manufacturing Industries andConstruction, Commercial, Residential, Agriculture), as a function of the main determining factors such as
operating conditions, vintage or equipment size.
Therefore, while this simplified approach allows improving, as much as possible, the completeness of theinventory, particularly for the developing countries, it neither guarantees the accuracy of the results, nor does itallow carrying out a quantified or even a qualitative quality control assessment.
Tier 2
Some representative detailed default emission factors are presented in the IPCC Guidelines for CH4, N2O, NOx,CO, and NMVOCs. As mentioned in the IPCC Guidelines, these data were derived from a few internationalsources (US-EPA, Radian 1990, etc.), and were already included in the first version of the OECD/IPCC Manual(1991). These emission factors were presented in five tables:
•

•

•

•

•

Table 1-15 - Utility boiler source performance:•

Emission performances are presented for 15 different coal technologies;•

Emission performances are presented for 6 different oil technologies;•

Emission performances are presented for 3 different Natural gas technologies, and•Emission performances are presented for 2 different Municipal Solid Waste Energy recovering
technologies.

Table 1-16 - Industrial boiler source performance:•

Emission performances are presented for 12 different coal technologies;•

Emission performances are presented for 8 different oil technologies;•

Emission performances are presented for 6 different Natural gas technologies, and•Emission performances are presented for 4 different wood technologies;•

Emission performances are presented for 6 different Municipal Solid Waste Energy recovering
technologies.

Table 1-17 - Kilns, Ovens, and dryers source performance:•

Emission performances are presented for 3 cement energy sources technologies;•

Emission performances are presented for 1 cooking steel energy source technology, and•Emission performances are presented for 3 chemical processes energy sources technologies.

Table 1-18 - Residential source performance:•

Emission performances are presented for 4 different coal technologies;•

Emission performances are presented for 4 different oil technologies;•

Emission performances are presented for 2 different Natural gas technologies, and•Emission performances are presented for 8 different wood technologies.

Table 1-19 - Commercial source performance:•

Emission performances are presented for 1 coal technology;•

Emission performances are presented for 6 different oil technologies;•

Emission performances are presented for 1 Natural gas technology;•

Emission performances are presented for 1 wood technology, and•Emission performances are presented for 3 different Municipal Solid Waste Energy recovering
technologies.

These EF’s are still useful in showing the range of emission rates according to the different sources. Howeverthese tables present many gaps particularly for N2O and NMVOCs, and the range is likely to be higher according
to the different determining factors. In addition, the standard deviation of the emissions is rarely reported.

Non-CO2 Emissions from Stationary Combustion47

Background Paper

According to a study (Eggleston and McInnes, 1987), variation of emission factors within energy activity ranges
from 20 to 50 percent.
If they are to be used by countries, these uncontrolled emission factors would have to be adjusted in order to take
into account any possible control policies that are in place in each OECD country. The IPCC Guidelines present
4 different tables of some emission control technologies in use in the OECD countries, and their representativeemission reduction rates:•

Table 1-20 - Utility boiler emission controls performance (23 alternative technologies);•

Table 1-21 - Industrial boiler emission controls performance (19 alternative technologies);•

Table 1-22 - Kilns, Ovens, and dryers emission controls performance (5 alternative technologies), and•Table 1-23 - Residential and Commercial emission controls performance (24 alternative technologies).

These tables are more relevant for large stationary sources and should be used in combination with the net
emission factors for each of the technologies considered in the Tier 2 approach.

2.3

Activity data

Activity data include the energy use (in TJ) in each of the concerned emitting sources. The availability and thelevel of details of the data determine, to a large extent, the approach to be adopted. While data at end-use levels
are not automatically available, some relevant approximation might be alternatively carried out by someindustrialized countries, given their well developed statistical infrastructure.
The Tier 2 approach requires more refined activity data, which should be combined with the default emission
factors that are suggested by IPCC Guidelines. When using this approach, it is necessary to have a goodknowledge of the technology split, and a minimum guarantee of the relevance of the adoption of the default
factors. Again, the use of this approach is possible after carrying out a good approximation of the activity data
figures for each kind of technology, and is conditioned by a minimum knowledge of the technologicalcharacteristics of the combustion plants in the country.
Ultimately, the aggregated approach (Tier 1) might help in presenting a more complete inventory. Activity data
include the energy use (in TJ) in each of the concerned energy consuming sectors by group of energy product.
Six groups of energy products were defined by the IPCC methodology: Coal, Natural Gas, Oil, Wood/Woodwaste and other Biomass and Wastes.
In general, the energy balance provide enough details to meet the minimum data requirements for the Tier 1
method. When the energy balance is not available for GHG inventory activities, a specific effort (realisticallyfeasible within the framework of the inventory activity) should be made in order to get the activity data.

2.4

Uncertainty

It is worth noting that uncertainty levels related to non-CO2 emissions associated with stationary combustion
sources are generally high. This is particularly true for the Non-Annex I countries, which are generally obliged toadopt aggregated emission factors. But it is also true for some Annex I countries. According to the first Reviewof the first National Communications of the Annex I Parties (UNFCCC 1997), the quality of the emission
estimate was quoted MEDIUM for CH4, and LOW to MEDIUM for N2O, CO and NMVOCs. For illustration,some Annex 1 Parties have even described the quality of the emission estimate due to stationary combustion for
CH4, N2O and NMVOCs as LOW.

2.5

Completeness

While the activity data should be completely available and accurate enough, at least for the Tier 1 approach, theavailability or adequacy of emission factors may dramatically limit the completeness of the estimates,
particularly for N2O. Countries might consider consulting other national communications, and adopting the mostappropriate EF according to the specific conditions of each country, in order to fill in the gaps. In any case, suchan approach will allow presenting estimates that are closer to the reality and therefore to improve thecomparability across national inventories.
In order to allow the comparability of inventories and review by any Party, as well as to improve theirtransparency, Parties are recommended to report the following:•48

Clear definitions of what is included in a particular IPCC source category (i.e., the sub-sources);

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Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories•

Clear definitions of thresholds for reporting, and the use of terms such as “Not Applicable (NA)”, “Not
Estimated (NE)”, and “Not Occurring (NO)”, and•Identification of the documentation needed to demonstrate completeness, including confirmation of
non-occurring sources.

2.6

Other important issues

Baseline emission determination
The non-CO2 emissions are the most sensitive to methodological development and emission factor changes. In
addition, given the low quality of the EF related to these gases, there are likely to be significant improvements inthe future with the development of statistical systems. Once a new approach, a new source or a new EF is
adopted, it is important to recalculate the previous historical estimates in order to keep consistency of the timeseries.
Treatment of emissions from pipeline transport
The emissions due to combustion in pipeline’s compression devices should be approached with the appropriate
guidance as to be realistically estimated. While the corresponding emissions might be included in the Transport
sector (although combustion plants are stationary), this might not be consistently understood, by the inventory
teams, and should therefore be better clarified by the IPCC guidelines.
Consistency among sources
The way to account for the emissions due to the combustion in coke ovens, particularly in the iron and steel
industry should be clarified, as well as possible double counting or omissions (e.g. energy combustion versus
industrial processes).
On the other hand, the approach to address the fuel gas, heat or the refinery gas that is recovered from primary
combustion activities should be clearly explained in the energy statistics so as to avoid double counting.

3

REPORTING AND DOCUMENTATIONThe Reporting Instructions of the Guidelines establish:•

A common Reporting Framework: Standard tables, definitions, units, and time intervals for reporting all
types of emissions to ensure consistency of reporting across countries;•

Documentation Standards: The necessary documentation to enable comparison of national inventories,
including worksheets, major assumptions, methodological descriptions, and enough data to allow a third
party to reconstruct the inventory from national activity data and assumptions, and•Verification and uncertainty assessment.

Non-CO2 emission tables are reported under the IPCC category I A within the Energy sector. The Reporting
instructions desegregate the non-CO2 emissions into sources (sectors) and sub-sources (sub-sectors or branches
are only considered for Energy Industries and Manufacturing Industries).
More aggregated Reporting tables consist of presentation of the emission results across sectors only
(commercial, residential and agriculture are grouped under a single row called: Other Sectors). General issues
such as supplemental reporting of emissions calculated with reference and default methods, baselines, timeseries, and double counting should be addressed in the context of individual sources.
In addition to the information currently requested by the IPCC inventory experts should discuss the suitability ofreporting the following information:•

An identification and description of the underlying method, including algorithms and equations;•

A discussion of methodological changes from previous years and the impact on estimates;•

An analysis of the trends, with special emphasis on explaining anomalies;•

All activity data, including any permutations performed on standard data to derive a value used in theinventory;•

All emissions factors, including explanations of why emissions factors were changed from previous years, and

Non-CO2 Emissions from Stationary Combustion

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Background Paper•

Complete bibliographical information for activity data and emissions factors.

4

QUALITY ASSURANCE AND QUALITYCONTROL (QA/QC)

An adequate quality assessment of an inventory requires both internal and external control procedures.
Internal control activities are intended to ensure accuracy, documentation and transparency of the inventory
operations. This control is first implemented by the agency that is responsible for compiling the inventory ineach country during the compilation of the data and calculations. Efforts should be made by this agency to check
actual data availability, correctness, consistency and completeness, and to document the origin of data and thespecific assumptions adopted. The implementation of an approved standardized procedure for emission
calculations may facilitate the accuracy of an inventory and the internal control.
In addition, the inventory activities should be implemented in a cooperative approach in such a way that the
specific skills needed in order to make decisions and assumptions could be provided by the different national
experts involved in the work. It is also highly recommended to systematically describe the specific context ofeach emission source in the inventory report, and to present the inventory results publicly so as to stimulate thefeedback from the national experts.
The external control is undertaken through relevant external reviews, and is designed to minimize the potential
errors and bias. The way in which the internal QA (quality assurance)/QC (quality control) is conducted
determines the potential conclusions of the external control.

4.1

General information requirements for QA/AC
systems

Prerequisites to data quality assurance for estimating non-CO2 emissions due to stationary combustion are
dependant on good data acquisition and handling procedures. The national data that are required to carry out theinventory generally come from the national energy statistics. However, accurate and updated, data should berequested from the direct energy consumers (e.g. Manufacturing Industrial units, etc.) or producers (Public
Utilities, Refineries, etc.), when the energy balance is not accurate enough.
In general, an inventory team that involves the major actors of the energy sectors should be constituted. This
ensures a rapid collection and good interpretation of the information.

4.2

Information needed to provide transparency

In addition to the inventory document, which should be in line with the IPCC Guidelines, all information that isneeded by any Party to understand the assumptions and the calculation approach should be reported.
It is important to describe and to list the types of information that should be provided and in which form theyshould be presented. For example, the national energy statistics might not be sufficient to recalculate theinventory. Moreover, it might be necessary where a Tier 2 approach was used, to provide some information on
the energy consumption by end-use, or the approaches used to determine them.

4.3 Public/peer reviews verification/validation
The GHG inventory should normally be reviewed and validated domestically prior to its publication. Regarding
Stationary Combustion, the full involvement of all actors at an early stage of the inventory process would reduce
the risks of wrong interpretation of the data or of producing highly uncertain estimates.
On the other hand, since the methodologies and approaches are still under development, it might be interesting toseek informal external review for the inventory report.

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5

IDENTIFICATION OF PRIORITY AREAS

With the exception of countries which rely heavily on biomass-energy in meeting their energy needs, thenon-CO2 emissions due to stationary combustion have generally a minor contribution to the emission budget interms of CO2 equivalent. However, in order to improve the completeness and the quality of the inventory there isa need to develop more appropriate emission factors. In addition, to some measurement campaigns, someresearch that attempts to link emission factors to operating conditions, for instance by region, could beundertaken. This would allow countries to complete a better estimate of their non-CO2 emissions.
Regarding biomass transformation and combustion, there is a need to develop more appropriate default emission
factors, particularly in small devices that are in use in developing countries.

REFERENCES
Berdowski, J., Olivier, J. and Veld, C. 1993a. Methane from fuel combustion and industrial processes. In A.R.
Amstel, (ed.), Proceedings of an International IPCC Workshop on Methane and Nitrous Oxide: Methods in
National Emissions Inventories and Options for Control. RIVM Report No. 481507003, Bilthoven, The
Netherlands.
Berdowski, J., Beck, L., Piccot, S., Olivier, J. and Veld, C. 1993a. Working group report: methane emissions
from fuel combustion and industrial processes. In A.R. Amstel, (ed.), Proceedings of an International IPCC
Workshop on Methane and Nitrous Oxide: Methods in National Emissions Inventories and Options forControl. RIVM Report No. 481507003, Bilthoven, The Netherlands.
Eggleston, H.S. and G. McInnes (1987), Method for the Compilation of UK Air Pollutant Emission Inventories.
Warren Spring Laboratory, Stevenage, UK.
IPCC Guidelines for National Greenhouse Gas Inventories- Volume 1.
IPCC Guidelines for National Greenhouse Gas Inventories- Volume 2.
IPCC Guidelines for National Greenhouse Gas Inventories- Volume 3.
UNFCCC Secretariat - Communications from Parties included in Annex I to the Convention FCCC/SBI/1997/INF4First Review of information communicated by each Party included in Annex 1 to The Convention - Compilationand synthesis of national communications from Annex I Parties - A/AC.237/81, December 1994.
Climate Change 1992 – The Supplementary Report to the IPCC Scientific Assessment
EMEP – Cooperative Programme for Monitoring and Evaluation of the Long Term Transmission of Air
Pollutants in Europe – CORINAIR – Atmospheric Emission Inventory Guide Book.

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Background Paper

ANNEX 1

THE AGGREGATED EMISSION FACTORS TABLESTABLE 2CH4 DEFAULT (UNCONTROLLED) EMISSION FACTORS (KG/ TJ)

Emitting Sources

Coal

Natural
Gas

Oil

Wood
/Wood
Waste

Charcoal

OtherbiomassandWastesEnergy Industries

1

1

3

30

200

30

(emission due to consumption)
Energy Industries

kg CH4/TJ(emissions due to Charcoal
Production)

wood input

300

kg CH4/TJ

1000

charcoal output
Manufacturing Industries and Construction

10

5

2

30

200

30

Other

Commercial/Institutional

10

5

10

300

200

300

Sectors

Residential

300

5

10

300

200

300

Stationary Agriculture/ Forestry /Fishing

300

5

10

300

200

300

TABLE 3
N2O DEFAULT (UNCONTROLLED) EMISSION FACTORS (KG/ TJ)
Emitting Sources

Coal

Natural
Gas

Oil

Wood
/Wood
Waste

Charcoal

OtherbiomassandWastes

1.4

0.1

0.6

4

4

4

Manufacturing Industries and Construction

1.4

0.1

0.6

4

4

4

Other

Commercial/Institutional

1.4

0.1

0.6

4

1

4

Sectors

Residential

1.4

0.1

0.6

4

1

4

Stationary Agriculture/
Forestry / Fishing

1.4

0.1

0.6

4

1

4

Energy Industries(emission due to consumption)
Energy Industries(emissions due to Charcoal
Production)

52

kg N2O /TJ woodinput
kg N2O /TJ
charcoal output

Energy Sector

Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories

TABLE 4
NOX DEFAULT (UNCONTROLLED) EMISSION FACTORS (KG/ TJ)
Emitting Sources

Coal

Natural
Gas

Oil

Wood
/Wood
Waste

Charcoal

OtherbiomassandWastesEnergy Industries

300

150

200

100

100

100

(emission due to consumption)
Energy Industries(emissions due toCharcoal Production)

kg NOx /TJ wood
input

5

kg NOx /TJ charcoal
output10

Manufacturing Industries and Construction

100

150

200

100

100

100

Other

Commercial/Institutional

100

50

100

100

100

100

Sectors

Residential

100

50

100

100

100

100

Stationary Agriculture/ Forestry /Fishing

100

50

100

100

100

100

TABLE 5CO DEFAULT (UNCONTROLLED) EMISSION FACTORS (KG/ TJ)
Emitting Sources

Coal

NaturalGas

Energy Industries

20

20

Oil

Wood
/Woo
d
Waste

Charcoal

OtherbiomassandWastes

15

1000

1000

1000

(emission due to consumption)
Energy Industries(emissions due to Charcoal
Production)

kg CO /TJ wood
input

2000

kg CO /TJ
charcoal output

7000

Manufacturing Industries and Construction

150

30

10

2000

4000

4000

Other

Commercial/Institutional

2000

50

20

5000

7000

5000

Sectors

Residential

2000

50

20

5000

7000

5000

Stationary Agriculture/ Forestry/ Fishing

2000

50

20

5000

7000

5000

Non-CO2 Emissions from Stationary Combustion

53

Background Paper

TABLE 6
NMVOCS DEFAULT (UNCONTROLLED) EMISSION FACTORS (KG/ TJ)
Emitting Sources

Coal

Energy Industries

5

Natural
Gas

Oil

Wood
/Wood
Waste

Charcoal

OtherbiomassandWastes

5

5

50

100

50

(emission due to consumption)
Energy Industries(emissions due to Charcoal
Production)

kg NMVOCs /TJ
wood input

600

kg NMVOCs /TJ
charcoal output

1700

Manufacturing Industries and Construction

20

5

5

50

100

50

Other

Commercial/Institutional

200

5

5

600

100

600

Sectors

Residential

200

5

5

600

100

600

Stationary Agriculture/
Forestry / Fishing

200

5

5

600

100

600

Source: 1996 IPCC Guidelines Vol. 2.

54

Energy Sector