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Industrial Processes

In the Danish emission inventories system emissions from industrial processes and product use (IPPU) are treated separately from emissions related to fuel consumption in the industry; these are included in the Energy Sector (Stationary combustion). IPPU emissions in Denmark are divided in seven main groups of sources;

  • A. Mineral Industry; includes emissions from cement production, lime production, glass production, production of ceramics, fluegas desulphurisation, mineral wool production, other process uses of soda ash, quarrying & mining, construction & demolition and storage, handling & transport of mineral products. The relevant pollutants are CO2, SO2, NMVOC, NH3, CO, particles (TSP, PM10, PM2.5), BC, heavy metals (Pb, Cd, As, Cr, Ni, Se, Zn), HCB, PCBs and PDCC/F.
  • B. Chemical Industry; includes emissions from production of sulphuric acid (ceased in 1997), nitric acid (ceased in 2004), production of catalysts/fertilizers, pesticides, tar products and other chemical ingredients. The relevant pollutants are CO2, N2O, SO2, NOx, NMVOC, NH3, particles (TSP, PM10, PM2.5), BC and Hg.
  • C. Metal Industry; includes emissions from iron foundries, steelworks, magnesium production (ceased in 2000), secondary aluminium production, secondary lead production and gun metal production (red bronze). The relevant pollutants are CO2, SF6, SO2, NOx, CO, NMVOC, particles (TSP, PM10, PM2.5), BC, heavy metals (Pb, Cd, Hg, As, Cr, Cu, Ni, Se, Zn), HCB, PCBs and PCDD/F.
  • D. Non-Energy Products from Fuels and Solvent Use; includes emissions from solvent use, road paving with asphalt, asphalt roofing, coating applications, dry cleaning, printing, chemical products, urea used in vehicle catalysts and paraffin wax use (candles). The relevant pollutants are CO2, CH4, N2O, NMVOC, particles (TSP, PM10, PM2.5), CO, PCDD/F and PAH.
  • E. Electronics Industry; includes fibre optics. The relevant pollutants are HCB and PCBs.
  • F. Product Uses as Substitutes for Ozone Depleting Substances; includes refrigeration, stationary and mobile air conditioning, foam blowing agents, aerosols and solvents. The relevant pollutants are HCB and PCBs.
  • G. Other Product Manufacture and Use; includes use of electrical equipment, use of running shoes, use of SF6 in laboratories, production of double glazed windows, medical application of N2O, propellant for pressure and aerosol products, use of other products (fireworks, tobacco and charcoal for barbeques), food & beverages industry, wood processing and slaughterhouse waste. The relevant pollutants are CO2, CH4, N2O, SF6, NOx, NMVOC, SO2, NH3, particles (TSP, PM10, PM2.5), CO, heavy metals (Pb, Cd, Hg, As, Cr, Cu, Ni, Se, Zn), PCDD/F, PAH, HCB and PCB.


The most important pollutants in the IPPU sector in 2017 are greenhouse gases (GHG) (especially CO2 and F-gasses), NMVOC, SO2, PM2.5 and some heavy metals. The IPPU sector makes up 4.0 % of the total national emission of greenhouse gasses (incl. LULUCF); hereof 4.0  % of the CO2 emission and all of the F-gas emissions. The corresponding percentage for NMVOC, SO2 and PM2.5 are 26.4 %, 15.2% and 4.3 %. A full list of the pollutants emitted from the IPPU sector with total 2017 emissions and the fraction of these emissions in relation to total national emissions are available in the linked Table 1.  The following figure presents the distribution of GHG, NMVOC, SO2 and PM2.5 emissions respectively on the individual subsectors in 2017.    

Figure 1   Distribution of the emissions from the IPPU sector.


GHG emission by source categoryNMVOC emission by source category
SO2 emission by source categoryPM2.5 emission by source category

For greenhouse gasses, the largest single source is cement production (A.1) with 1194 Gg CO2 (59 % of total IPPU GHG emission), the second largest is refrigeration and air conditioning (F.1) with 388 Gg CO2e (19 % of total IPPU GHG emission).  

Only four sources contribute to the SO2 emission in 2017; production of ceramics (A.4) (1.50 Gg), production of catalysts (B.10) (0.02 Gg), lead production (C.5) (0.004 Gg) and use of other products (G.4) (0.03 Gg). Lastly, for PM2.5 emissions, the largest contributing sources are quarrying and mining of minerals other than coal (A.5a) with 0.25 Gg (30 %) and use of other products (G.4) with 0.24 Gg (29 %) (primarily caused by the use of tobacco).    


The trends of the individual greenhouse gasses along with the total GHG emission are presented in Figure 2. The decrease in emission of CO2 in 2008-2009 may be explained by the decrease in economic activity. 

Figure 2   Total emission and emission of the individual greenhouse gasses from the IPPU sector, and total emission and emission from individual sources for NMVOC, SO2 and PM2.5.


Time-series for GHG emissions from the IPPU sector

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Time-series for NMVOC emissions from the IPPU sector

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Time-series for SO2 emissions from the IPPU sector

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Time-series for PM2.5 emissions from the IPPU sector

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NMVOCs are not considered direct greenhouse gases, but their role as precursors in tropospheric ozone formation, which is a greenhouse gas, justifies their inclusion in a greenhouse gas inventory. Although the CO2 contribution is relatively small compared to e.g. carbonate use, the emissions are included in the national GHG emission inventories as CO2. For NMVOC the largest sources are solvent use (D. 3i) and chemical products (D.3g) with 13.7 Gg (51 % of IPPU) and 4.6 Gg (17 % of IPPU) respectively.

The main source of NMVOC emissions in the IPPU sector is solvent use. Solvents are chemical compounds which are used on a global scale in industrial processes and as constituents in final products to dissolve e.g. paint, cosmetics, adhesives, ink, rubber, plastic, pesticides and aerosols. The most abundantly used NMVOC as solvent are ethanol, turpentine (white spirit defined as a mixture of stoddard solvent and solvent naphtha) and propylalcohol. Ethanol is used as solvent in the chemical industry and as windscreen washing agent. Turpentine is used as thinner for paints, lacquers and adhesives. Propylalcohol is used in cleaning agents in the manufacture of electrical equipment, flux agents for soldering, as solvent and thinner and as windscreen washing agent. Household emissions are dominated by propane and butane, which are used as aerosols in spray cans, primarily in cosmetics.

Emission of SO2 is mainly caused by the production of ceramics; between 67 % (in 1989) and 96 % (in 2007). The fluctuations in the SO2 emission during the time series are primarily caused by variations in the building/construction activities and the strong decline in emissions from 2007-2009 is due to the economic recession caused by the global financial crisis.

The vast majority of nitrous oxide emissions (98 % in average) were caused by nitric acid production, the emissions therefore decreased drastically when the singular production site closed down in 2004. This shut down also caused a significant decrease in particle emissions. While PM2.5 emissions from construction and demolition have been increasing (until the years of the global financial crisis) emissions from glass production and steel production (due to the closing of the one Danish electro steelwork in 2005) have been decreasing. 

Emissions from the IPPU sector are calculated based on information given in annual environmental reports/PRTR, through contact with the companies, national statistics and modelling. Also, activity data and emissions from the EU Emission Trading Scheme (EU ETS) are used. International literature or default values given in international inventory guidelines (IPCC Guidelines and EMEP/EEA Emission Inventory Guidebook) are used where no country specific data are available.     

For more information on the methodology and data used in the inventory of emissions of industrial processes, see the latest sector report Danish Emission Inventory for Industrial Processes.