Aarhus University Seal / Aarhus Universitets segl

No. 94: Annual Danish Informative Inventory Report to UNECE. Emission inventories from the base year of the protocols to year 2012

Nielsen, O.-K., Winther, M., Mikkelsen, M.H., Hoffmann, L., Nielsen, M., Gyldenkærne, S., Fauser, P., Plejdrup, M.S., Albrektsen, R., Hjelgaard, K. & Bruun, H.G. 2014. Annual Danish Informative Inventory Report to UNECE. Emission inventories from the base year of the protocols to year 2012. Aarhus University, DCE–Danish Centre for Environment and Energy, 759 pp. Scientific Report from DCE–Danish Centre forEnvironment and Energy No. 94. http://dce2.au.dk/pub/SR94.pdf

Summary

I Background information on emission inventories

Annual report
This report is Denmark’s Annual Informative Inventory Report (IIR) due March 15, 2014 to the UNECE Convention on Long-Range Transboundary Air Pollution (LRTAP). The report contains information on Denmark’s inventories for all years from the base years of the protocols to 2012.

The air pollutants reported under the LRTAP Convention are SO2, NOX, NMVOC, CO, NH3, TSP, PM10, PM2.5, As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Zn, dioxins/furans, HCB, PCBs and PAHs,.

The annual emission inventory for Denmark is reported in the Nomenclature for Reporting (NFR 2009) format. In December 2008 the current reporting guidelines were adopted by the EMEP Executive Body. Many of the new elements and demands in the reporting guidelines have not been implemented yet. The reason for this is that they require significantly more resources, which are not currently available.

The issues addressed in this report are: trends in emissions, description of each NFR category, uncertainty estimates, recalculations, planned improvements and procedures for quality assurance and control. The structure of the report follows to the extent possible the proposed outline.

Information contained in this report is available to the public on the Danish Centre for Environment and Energy (DCE), Aarhus University’s homepage:
http://envs.au.dk/videnudveksling/luft/emissioner/emissioninventory/

and this report and the NFR tables are available on the Eionet central data repository:
http://cdr.eionet.europa.eu/dk/Air_Emission_Inventories/Submission_EMEP_UNECE

Responsible institute
DCE-Danish Centre for Environment and Energy, Aarhus University, is on behalf of the Danish Ministry of the Environment responsible for the annual preparation and submission to the UNECE-LRTAP Convention of the Annual Danish Emissions Report and the inventories in the NFR format. DCE participates in meetings under the UNECE Task Force on Emission Inventories and Projections and the related expert panels, where parties to the convention prepare the guidelines and methodologies on inventories.

II Trends in emissions

Acidifying gases
In 1990, the relative contribution in acid equivalents was almost equal for the three gases SO2, NOx and NH3. In 2012, the most important acidification factor in Denmark is ammonia nitrogen and the relative contributions for SO2, NOX and NH3 were 5 %, 34 % and 61 %, respectively. However, with regard to long-range transport of air pollution, SO2 and NOX are still the most important pollutants.

Sulphur dioxide (SO2)
The main part of the SO2 emission originates from combustion of fossil fuels, i.e. mainly coal and oil, in public power and district heating plants. From 1990 to 2012, the total emission decreased by 93 %. The large reduction is mainly due to installation of desulphurisation plants and use of fuels with lower content of sulphur in public power and district heating plants. Despite the large reduction of the SO2 emissions, these plants make up 25 % of the total emission. Also emissions from industrial combustion plants, non-industrial combustion plants and other mobile sources are important. National sea traffic (navigation and fishing) contributes with about 13 % of the total SO2 emission in 2012. This is due to the use of residual oil with high sulphur content.

Nitrogen oxide (NOx)
The largest sources of emissions of NOX are road transport followed by other mobile sources and combustion in energy industries (mainly public power and district heating plants). The transport sector is the sector contributing the most to the emission of NOX and, in 2012, 49 % of the Danish emissions of NOX stems from road transport, national navigation, railways and civil aviation. Also emissions from national fishing and off-road vehicles contribute significantly to the NOX emission. For non-industrial combustion plants, the main sources are combustion of gas oil, natural gas and wood in residential plants. The emissions from energy industries have decreased by 77 % from 1990 to 2012. In the same period, the total emission decreased by 58 %. The reduction is due to the increasing use of catalyst cars and installation of low-NOX burners and denitrifying units in power plants and district heating plants.

Ammonia (NH3)
Almost all atmospheric emissions of NH3 result from agricultural activities. Only a minor fraction originates from road transport (2.0 %) and stationary combustion (0.2 %) in 2012. This share for road transport increased during the 1990’s and early 2000’s due to growing use of catalyst cars. In more recent years the share is again decreasing due to more advanced catalysts being implemented. The major part of the emission from agriculture stems from livestock manure (80 %) and the largest losses of ammonia occur during the handling of the manure in stables and in field application. Other contributions come from use of mineral fertilisers (10 %), N-excretion on pasture range and paddock (3 %), sewage sludge used as fertiliser, crops and ammonia used for straw treatment (7 %) and field burning (less than 1 %). The total ammonia emission decreased by 39 % from 1990 to 2012. This is due to the active national environmental policy efforts over the past twenty years.

Other air pollutants

Non-methane volatile organic compounds (NMVOC)
The emissions of NMVOC originate from many different sources and can be divided into two main groups: incomplete combustion and evaporation. Road vehicles and other mobile sources such as national navigation vessels and off-road machinery are the main sources of NMVOC emissions from incomplete combustion processes. Road transportation vehicles are still the main contributors, even though the emissions have declined since the introduction of catalyst cars in 1990. The evaporative emissions mainly originate from the use of solvents and the extraction, handling and storage of oil and natural gas. The emissions from the energy industries have increased during the nineties due to the increasing use of stationary gas engines, which have much higher emissions of NMVOC than conventional boilers. The total anthropogenic emissions have decreased by 52 % from 1990 to 2012, largely due to the increased use of catalyst cars and reduced emissions from use of solvents.

Carbon monoxide (CO)
Mobile sources and non-industrial combustion plants contribute significantly to the total emission of this pollutant. Transport is the second largest contributor to the total CO emission. In 1990 a law forbidding the burning of agricultural crop residues in the fields was implemented, which caused a significant reduction in CO emission. The emission decreased further by 51 % from 1990 to 2012, largely because of decreasing emissions from road transportation.

Particulate Matter (PM)
The particulate matter (PM) emission inventory has been reported for the years 2000 onwards. The inventory includes the total emission of particles Total Suspended Particles (TSP), emission of particles smaller than 10 µm (PM10) and emission of particles smaller than 2.5 µm (PM2.5).

The largest PM2.5 emission sources are residential plants (67 %), road traffic (10 %) and other mobile sources (8 %). For the latter, the most important sources are off-road vehicles and machinery in the industrial sector and in the agricultural/forestry sector (32 % and 37 %, respectively). For the road transport sector, exhaust emissions account for the major part (60 %) of the emissions. The PM2.5 emission increased by 3 % from 2000 to 2011, due to an increasing wood consumption in the residential sector counteracted by a decrease in emission from the transport sector and to a less degree from manufacturing industries and construction.

The largest TSP emission sources are the residential sector and the agricultural sector. The TSP emissions from transport are also important and include both exhaust emissions and the non-exhaust emissions from brake and tyre wear and road abrasion. The non-exhaust emissions account for 65 % of the TSP emission from road transport in 2012.

Heavy metals

In general, the most important sources of heavy metal emissions are combustion of fossil fuels and waste. The heavy metal emissions have decreased substantially in recent years, except for Cu. The reductions span from 27 % to 91 % for Zn and Pb, respectively. The reason for the reduced emissions is mainly increased use of gas cleaning devices at power and district heating plants (including waste incineration plants). The large reduction in the Pb emission is due to a gradual shift towards unleaded gasoline, the latter being essential for catalyst cars. The major source of Cu is automobile tyre and break wear (94 % in 2012) and the 30 % increase from 1990 to 2012 owe to increasing mileage.

Cadmium (Cd)
The main sources of emissions of Cd to air are combustion in energy industries (mainly combustion of wood, wood waste and municipal waste) and manufacturing industries (mainly combustion of residual oil). In the transport sector emissions from passenger cars is the main source contributing with 57 % of the sectoral emission in 2012. The emission from non-industrial combustion is dominated by wood combustion in residential plants which accounts for 76 % of the sectoral emission in 2012. Emissions from combustion in residential plants have increased by 97 % since 1990. The decreasing emission from energy industries are related to the decreasing combustion of coal.

Mercury (Hg)
The largest sources of Hg emissions to air are waste incineration and coal combustion in energy industries. Due to improved flue gas cleaning and decreasing coal combustion the emissions from energy industries decreased by 76 % from 1990-2000. The trend has continued in the following years and the corresponding decrease from 1990-2012 is 93 %. Non-industrial combustion is dominated by wood combustion in residential plants while emissions from the waste sector mainly owe to cremation. The variations in emissions from industrial processes owe to shut down in 2002 followed by re-opening and a second shut down in 2005 of the only Danish electro-steelwork.

Lead (Pb)
The main Pb emission sources are combustion in residential plants and energy industries and transport. In earlier years combustion of leaded gasoline was the major contributor to Pb emissions to air but the shift toward use of unleaded gasoline for transport have decreased the Pb emission from transport by 94 % from 1990 to 2012. In the non-industrial combustion sector the dominant source is wood combustion in residential plants. The trend in the Pb emission from non-industrial combustion from 1990 to 2011 is almost constant. This is due to a decrease in emission caused by the shift towards unleaded gasoline, as this sector includes other mobile sources in household, gardening, agriculture, forestry, fishing and military. This is counteracted by an increase in the emission from residential plants. The decreasing emission from energy industries (97 % from 1990 to 2012) is caused by the deceasing coal combustion.

Polycyclic aromatic hydrocarbons (PAHs)
The present emission inventory for polycyclic aromatic hydrocarbons (PAH) includes four PAHs: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluor-anthene and indeno(1,2,3-cd)pyrene. Benzo(b)fluoranthene and Benzo(a)py-rene contribute the major PAH emission by 34 % and 32 %, respectively in 2012. The most important source of PAHs emissions is combustion of wood in the residential sector making up 71 % of the total emission in 2012. The increasing emission trend is due to increasing combustion of wood in the residential sector. The PAH emission from combustion in residential plants has increased by 93 % from 1990 to 2012.

Dioxins and furans
The major part of the dioxin emission owes to wood combustion in the residential sector, mainly in wood stoves and ovens without flue gas cleaning. Wood combustion in residential plants accounts for 60 % of the national dioxin emission in 2012. The contribution to the total dioxin emission from the waste sector (25 % in 2012) owes to accidental fires, especially building fires. The emissions of dioxins from energy industries mainly owe to the combustion of biomass as wood, wood waste and to a less extend agricultural waste.

Hexachlorobenzene (HCB)
Stationary combustion accounts for 66 % of the estimated national hexachlorobenzene (HCB) emission in 2012. This owes mainly to combustion of municipal solid waste in heating and power plants. Transport is an important source too and has increased by 58 % since 1990 due to increasing diesel consumption. The HCB emission from stationary plants has decreased 74 % since 1990 mainly due to improved flue gas cleaning in MSW incineration plants. The emission from agriculture was very high in the early 1990s due to the use of pesticides containing impurities of HCB. The HCB emission from agriculture decreased by 94 % from 1990 to 1994, and by 99 % from 1990 to 2012, causing the share of HCB emission from agriculture to drop from 69 % in 1990 to 5 % in 2012.

Polychlorinated biphenyls (PCBs)
Transport accounts for 59 % of the estimated national polychlorinated biphenyls (PCBs) emission in 2012. This owes mainly to combustion of diesel in road transport. The emission from transport has decreased by 73 % since 1990 due to the phase out of leaded gasoline, which has a high PCBs emission factor. This has led to diesel fuel use being the most important source of PCBs emissions from transport in later years. The emission from manufacturing industries and non-industrial combustion is dominated by diesel fuel used in non-road machinery.

III Recalculations and Improvements

In general, considerable work is being carried out to improve the inventories. Investigations and research carried out in Denmark and abroad produce new results and findings, which are given consideration and, to the extent which is possible, are included as the basis for emission estimates and as data in the inventory databases. Furthermore, the updates of the EMEP/EEA Guidebook, and the work of the Task Force on Emission Inventories and its expert panels are followed closely in order to be able to incorporate the best scientific information as the basis for the inventories.

The implementation of new results in inventories is made in a way so that improvements, as far as possible, better reflect Danish conditions and circumstances. This is in accordance with good practice. Furthermore, efforts are made to involve as many experts as possible in the reasoning, justification and feasibility of implementation of improvements.

In improving the inventories, care is taken to consider implementation of improvements for the whole time series of inventories to make it consistent. Such efforts lead to recalculation of previously submitted inventories. This submission includes recalculated inventories for the whole time series. The reasoning for the recalculations performed is to be found in the sectoral chapters of this report. The text below focuses on recalculations, in general, and further serves as an overview and summary of the relevant text in the sectoral chapters. For sector specific planned improvements please also refer to the relevant sectoral chapters.

Energy
Improvements and updates of the Danish energy statistics are made regularly by the producer of the statistics, the Danish Energy Agency. In close cooperation with the DEA, these improvements and updates are reflected in the emission inventory for the energy sector. The Danish energy statistics have, for the most part, been aggregated to the SNAP categorisation.

The inventories are still being improved through work to increase the number of large point sources, e.g. power plants, included in the databases as individual point sources. Such an inclusion makes it possible to use plant-specific data for emissions, etc., available e.g. in annual environmental reports from the plants in question.

Stationary Combustion
For stationary combustion plants, the emission estimates for the years 1990-2011 have been updated according to the latest energy statistics published by the Danish Energy Agency. The update included both end use and transformation sectors as well as a source category update. The changes in the energy statistics are largest for the years 2009, 2010 and 2011.

The emission factors for residential wood combustion have been revised according to the EEA Guidebook update (EEA, 2013). This has caused large recalculations for residential plants.

The HCB emission inventory has been improved and an emission inventory for dioxin-like PCB has been elaborated.

Mobile sources

The following recalculations and improvements of the emission inventories have been made since the emission reporting in 2013.

Road transport
Based on the updated version of COPERT IV launched in 2013, new vehicle sub categories have been introduced in the emission inventories for mopeds and passenger cars. For mopeds a division is now made between 2-stroke and 4-stroke engine technologies and for passenger cars small engine sizes below 0.8 l. for gasoline and below 1.4 l. for diesel have been included. Also NOx emission factors for euro 5 diesel passenger cars have been updated in the model based on the new COPERT IV version.

Small errors in input gasoline fuel consumption for the years 2009-2011 and for input diesel fuel consumption in the years 2010-2011 have been corrected.

The percentage emission change interval and year of largest percentage differences (low %; high %, year) for the different emission components are: SO2 (-0.5 %; 0.0 %, 2008), NOx (0.0 %; 4.3 %, 2011), NMVOC (-4.1 %; -1.1 %, 2011), NH3 (-1.3 %; 0.1 %, 2008) and TSP (-2.1 %; 0.0 %, 2011).

Navigation
Minor changes in ferry input data have been made for the years 2008-2011 causing minor emission changes for domestic navigation. The following largest percentage differences (in brackets) for domestic navigation are noted for: SO2 (-0.2 %), NOx (-0.3 %), NMVOC (-0.5 %), NH3 (0.0 %) and TSP (-0.5 %).

Agriculture/forestry/fisheries
The number and engine size of machine pool tractors has been updated for the years 2007-2011. The number of ATV’s has been changed for the years 2009-2011.

Errors in the fuel consumption for fisheries in 2000, 2010 and 2011 have been corrected.

In 2000 the following percentage differences (in brackets) for agriculture/forestry/fisheries are noted for: SO2 (18.2 %), NOx (11.1 %), NMVOC (3.1 %), NH3 (0.0 %) and TSP (3.1 %). due to fuel consumption changes in fisheries.

For other years than 2000, the following largest percentage differences (in brackets) are noted for: SO2 (-12.1 %), NOx (-6.4 %), NMVOC (-0.8 %), NH3 (1.7 %) and TSP (-2.2 %).

Industry
The number of mini loaders has been updated for the years 2004-2011.

The following largest percentage differences (in brackets) for industrial non road machinery are noted for: SO2 (1.7 %), NOx (1.6 %), NMVOC (1.9 %), NH3 (1.6 %) and TSP (3.4 %).

Civil aviation
A small error in the NMVOC emission factor has been corrected for the years 1985-2011, due to CH4 emission factor updates from 1985-2000 and corrections in the general NMVOC-CH4 split of VOC. The emission factors are now in line with the factors proposed by the EMEP/EEA emission inventory guidebook. The NMVOC emission percentage differences are between -3.1 % and 1.8 %.

Military
Emission factors derived from the new road transport simulations have caused some emission changes from 1985-2011. The following largest percentage differences (in brackets) for military are noted for: SO2 (0.0 %), NOx (2.5 %), NMVOC (-1.1 %), NH3 (0.2 %) and TSP (-1.7 %).

Fugitive emissions

Service stations
The activity data has been updated for 2009-2011 according to the latest energy statistics published by the Danish Energy Agency. The largest recalculation for 2010 has changed the NMVOC emission by 0.02 ktonnes, corresponding 0.2 % of the total fugitive NMVOC emission in 2010.

Natural gas transmission and distribution
Activity data and IEF for the time series 1990-2011 has been updated for transmission and distribution according to annual environmental reports and the latest national energy statistics, respectively. The largest recalculation for 2002 has changed the NMVOC emission by 0.75 ktonnes, corresponding 4 % of the total fugitive NMVOC emission in 2010.

Venting
EFs for NMVOC have been added for the years 1990-1993 for one gas storage plant. In these years the plant is treated as an area source in the national system, while it is treated separately as a LPS in the following years. EFs are based on data from annual reports for 1995-1999, as no data are available for the years 1990-1994.

Further, a minor error has been applied for venting in 2011, according to the annual report from one of the natural gas storage facilities.

The recalculation has changed the NMVOC emission by 0.02 ktonnes and the CO emission by 0.07 ktonnes for each of the years 1990-1993, corresponding 17% and 25 % of the total fugitive NMVOC and CO emission in 1993, respectively.

Industrial processes
Emissions of HCB and PCBs have been included in the emission inventory. Also, emissions from production of tar products have been included.

Solvent and other product use
Improvements and additions are continuously being implemented due to the comprehensiveness and complexity of the use and application of solvents and solvent containing products in industries and households. The main recalculations and their implications on the emissions in the 2014 reporting include the following:

  • Updated statistical data for the activities of tobacco, fireworks, candles and charcoal for barbequing
  • Emission factors for NH3, PCB, HCB, Cu, benzo(b)flouranthene, benzo(k)flouranthene, benzo(a)pyrene and PCBs have been added for charcoal for barbequing and PM10 and PM2.5 have been added for the burning of candles. Furthermore, emission factors for Cr, TSP, PM10 and PM2.5 have been updated for charcoal for barbequing.

Agriculture
Compared with the previous NH3 and PM emissions inventory (submission 2013), some changes and updates have been made, see Table 6.24. These changes cause a relatively high increase in the NH3 emission for all years (1985–2011) between 5-10 % and a decrease in the PM emission 2000-2011 by 3-5 %.

The emission of NH3 has increased all years due to change in the emission factor for synthetic fertiliser as a consequence of updating of the EMEP/EEA Guidebook (2013). Some other changes have been made, which slightly increases the emission of NH3 from manure management; number of geese all years, number of weaners and fattening pigs in 2011 and change of distribution of housings for hens, also in 2011.

Emission of PM TSP decreased all years due to changes of emission factor in the revised EMEP/EEA Guidebook (2013). The overall decrease is mainly due to decrease in emission factor for fattening pigs and weaners.

Waste
For sector 6.C. Waste Incineration; changes were made to the human cremation with flue gas cleaning emission factors for heavy metals (HMs), PAHs and PCDD/Fs, the abatement of these pollutants by the newly installed flue gas cleaning equipment have not previously been included in this report, this change reduces the listed pollutants for 2011. Furthermore, an error has been corrected for the PM2.5 emission factor for human cremation, as, correctly described in the text, the PM2.5 emission is estimated as 80 % for the TSP and not 90 % as reported in the last submission; this correction reduces the PM2.5 emission for 2000-2010.

For sector 6.D. Waste Other several recalculations were made. NH3 emission factors for composting of sludge and organic municipal waste have been updated. These new emission factors causes a decrease in NH3 emissions for 1985-1997 (0.3-0.7 %) and an increase for 1998-2011 (2.1-19.3 %)

For accidental vehicle fires, an update in vehicle population data has given a small decrease in the FSE activity data for accidental tractor and combined harvester fires. In addition to this, the average weight of caravans, motorhomes, combined harvesters and motorcycles/mopeds have been updated to more well-founded expert judgments. Finally the emission factors for particles and heavy metals have been updated. While the changes in activity data leads to a general decrease in emissions for 1980-1999 (-16 % to -5 %) and only subtle changes for 2000-2011 (-5 % to 4 %), the new emission factors results in a strong increase in particle and heavy metal emissions for all years 1980-2011 (1413-1874 %).

There are no recalculations for accidental building fires.