Nielsen, O.-K., Nielsen, M. & Illerup, J.B. 2007. NERI Technical Report no. 628. pp 176.
Summary
Danish emission inventories are prepared on an annual basis and are reported to the UNECE Framework Convention on Climate Change (UNFCCC or Climate Convention) and to the UNECE Convention on Long-Range Transboundary Air Pollution (LRTAP Convention). Furthermore, a greenhouse gas emission inventory is reported to the EU, due to the EU – as well as the individual member states – being party to the Climate Convention. The annual Danish emission inventories are prepared by the Danish National Environmental Research Institute (NERI). The inventories include the pollutants: CO2, CH4, N2O, SO2, NOX, NMVOC, CO, particulate matter, heavy metals, dioxins and PAH. In addition to annual total emissions, the report includes sector specific emissions and uncertainty estimates. Every five years the reporting includes data on the geographical distribution of the emissions, a projection of emissions data and details of the activity data – e.g. fuel consumption – on which the inventories are based.
The inventories are based on the Danish energy statistics and on a set of emission factors for various sectors, technologies and fuels. Plant specific emissions for large combustion sources are incorporated into the inventories. This report provides detailed background information on the methodology and references for the input data in the inventory - energy statistics and emission factors.
The emission factors are based either on national references or on international guidebooks (EMEP/Corinair 2004 and IPCC 1996). The majority of the country-specific emission factors refer to: Danish legislation, Danish research reports or calculations based on plant-specific emissions from a considerable number of large point sources. The plant-specific emission factors are provided by plant operators, e.g. in annual environmental reports.
In the inventory for the year 2004, 72 stationary combustion plants are specified as large point sources. The point sources include large power plants, municipal waste incineration plants, industrial combustion plants and petroleum refining plants. The fuel consumption of these large point sources corresponds to 64% of the overall fuel consumption of stationary combustion.
The Danish fuel consumption rate fluctuates due to the import/export of electricity. Since 1990 fuel consumption has increased by 13%, fossil fuel consumption, however, only increasing by 4,2%. The use of coal has decreased whereas the use of natural gas and renewable fuels has increased.
Stationary combustion plants account for more than 50% of the total Danish emission for the following pollutants: SO2, CO2, heavy metals (except Cu) PM2.5 and PAH. Furthermore, emissions from stationary combustion plants account for more than 10% of the total Danish emission for the following pollutants: NOX, CO, NMVOC, TSP, PM10 and Cu. Stationary combustion plants account for less than 10% of the total Danish CH4 and N2O emission.
Public power plants represent the most important stationary combustion emission source for SO2, CO2, NOX and heavy metals.
Lean-burn gas engines installed in decentralised CHP plants are the largest emission source for CH4. Furthermore, these plants also represent a considerable emission source for NMVOC.
Residential plants are the most important stationary combustion source for CO, NMVOC, particulate matter and PAH. Wood combustion in residential plants is the predominant emission source.
The report in hand includes time-series for stationary combustion plants for the range of pollutants.
The development in greenhouse gas (GHG) emission follows that of CO2 emission very closely. Both CO2 and the total GHG emission were lower in 2004 than in 1990: CO2 by 5% and GHG by 4%. However, fluctuations in the GHG emission level are significant, the fluctuations in the time-series arising from electricity import/export and outdoor temperature variations from year to year.
The CH4 emission from stationary combustion has increased by a factor of 4,3 since 1990. This is a result of the considerable number of lean-burn gas engines installed in CHP plants in <st1:place w:st="on"><st1:country-region w:st="on">Denmark</st1:country-region></st1:place> during this period.
SO2 emission from stationary combustion plants has decreased by 95% from 1980 and 84% from 1995. The large emission decrease is mainly a result of the reduced emission from electricity and district heat production made possible by installation of desulphurisation plants and due to the use of fuels with lower sulphur content.
The NOX emission from stationary combustion plants has decreased by 50% since 1985 and 33% since 1995. The reduced emission is mainly a result of the reduced emission from electricity and district heat production plants in which the use of low NOX burners has increased. Also, de-NOX flue gas cleaning units have been put into operation in a greater number of the larger power plants. The fluctuations in the time-series follow fluctuations in fuel consumption in power plants, these occurring due to electricity import/export.
Wood consumption in residential plants has increased by 94% since 1990 causing an increase in the CO emission. The increase in CO from residential plants is less steep than the increase in wood consumption as the CO emission from straw-fired farmhouse boilers has decreased considerably.
The NMVOC emission from stationary combustion plants has increased by 51% from 1985 and 22% from 1995. The increased NMVOC emission results mainly from the increased use of lean-burn gas engines.
All heavy metal emissions have decreased considerably since 1990 – between 7% and 85%. The decreases result from improvements in flue gas cleaning systems installed in municipal waste incineration plants and in power plants.
The PAH emission has increased since 1990 due to increased combustion of wood in residential plants.
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