| Front page | | Contents | | Previous | | Next |

Denmark's Greenhouse Gas Projections until 2012, an update including a preliminary projection until 2017

4 Industrial Processes

Greenhouse gases are produced from a variety of industrial activities, which are not related to energy. This section covers the emissions from industrial production processes, which chemically or physically transform materials. For Denmark this means CO₂ emissions from the production of cement, lime and yellow bricks, and emissions of HFCs, PFCs and SF₆.

4.1 Mineral Products

4.1.1 Cement, lime and yellow bricks production

Only the mineral products sector is contributing to the emission of CO₂. In 2000 a total of 1.46 million tonnes of CO₂ originated from production of cement, lime and yellow bricks. According to Table 3 this is an increase of about 50% from the 1.0 MtCO₂ in 1990. However, the present level of emissions are not expected to increase in the period until 2012.

The CO₂ emissions from cement production are shown in Figure 6. In 2000 the emission was 1.35 million tonnes of CO₂. Since 1990 the emission has been increasing due to the increase in building activity. The Ålborg Portland plant is now running at its full capacity, it is therefore assumed that the Danish CO₂ emission form cement production will not increase in the period to 2010, since it will take 5-10 years for a new cement plant to be operational after the decision to build it.

Figure 6.
CO₂ emission from cement production

The curve in Figure 6 is based on information from Ålborg Portland [17]. The total CO₂ emissions in the figure consist of two parts: The emissions from white cement calculated the amount of white cement produced multiplied by an emission factor of 0.669 t CO₂/t cement. The CO₂ emission from grey cement is calculated as the amount of grey cement weighted by the relative fractions of the three types of clinker multiplied by the three respective emission factors shown in Table 13 [17].

Table 13.
CO₂ emission factors for grey cement

The source of information for the production of bricks and lime is the Industrial Sales Statistics [18]. Assuming that half of the bricks are yellow bricks, their production gives rise to an emission of 0.158 kg CO₂/brick [19]. This emission factor is calculated the following way. When limestone (CaCO₃) is heated it decomposes into lime (CaO) and CO₂. Using the molecular weights, 44 kg of CO₂ is emitted for every 100 kg CaCO₃ decomposed. Since clay used to produce yellow bricks contains 18% limestone and the average weight of a brick is 2 kg, the emission factor is 2*0.18*0.44= 0.158. With the annual production of yellow bricks shown in Table 14, the emissions from brick production was in the range 0.02-0.03 million tonnes of CO₂ in the period 1988-2000.

If the amount of yellow bricks used in Denmark is projected with the long range annual increase of 1.5% p.a. used in the ADAM projections for the supplier of building materials made by Denmark's Statistics, the CO₂ emissions from yellow bricks will increase to 0.04 Mt CO₂ in 2010.

Table 14.
CO₂ emissions from production of yellow bricks

The production of lime emits 0.785 t CO₂/t burned lime (standard IPCC value), since 44.01 kg of CO₂ is emitted for every 56.08 kg of CaO produced, according to the molecular weights in the two products in the disintegration of CaCO₃. According to Table 15 the annual emission from lime production was in the range 0.07-0.10 million tonnes of CO₂ in the period 1988-2000.

Table 15.
CO₂ emissions from production of burned lime.

4.1.2 HFCs, PFCs and SF₆

This section contains a projection of the emissions of three groups of greenhouse gases, perfluorocarbons (PFCs), sulphur hexafluoride (SF₆), and hydrofluorocarbons (HFCs) through to the year 2020. These gases were added to the gases CO₂, CH₄ and N₂O under the 1997 Kyoto Protocol to the United Nations Framework Convention on Climate Change. The GWPs of the gases are shown in Table 1.

The information in Table 16 is from a report made by COWIconsult [20]. The emission levels have decreased compared to former reports for several reasons:

1. Because the actual emissions have been corrected for the greenhouse gases contained in the exported and imported appliances.
2. A tax has been introduced on these three groups of gases amounting to 1/10^th of their GWP in Table 1 up to a maximum of 400 kr/kg.
3. New Danish legislation containing dates for outphasing import, production and use of these industrial greenhouse gasses.
4. New rules for decommissioning, where the GHG in refrigerators, foam etc. are destroyed instead of emitted to the atmosphere. This is a mayor reason for the decrease in the present projection compared to the last one in [58]. The difference with the old calculation is especially large in the second commitment period, 2013-17 (marked as "2015").
5. Further there have been changes in the leak-rates for commercial and mobile refrigerants. The reduction in leak-rates decreases the emission form those sources with a smaller amount.

In agreement with Article 3.8 of the Kyoto Protocol, the Denmark has chosen 1995 as the base year for HFCs, PFCs and SF₆ [57]. The total emission of the three groups of gases increase from 0.35 Mt CO₂ in 1995 to the peak of 0.81 Mt CO₂ in 2000. Thereafter the emission decrease gradually to 0.71 Mt CO₂ in "2010" and further to 0.50 Mt CO₂ in "2015".

The emissions are calculated using the IPCC method for actual emission, taking into account the time lag between consumption and emission, which may be considerable in some application areas, e.g. closed cell foams and refrigeration.

Hydrofluorocarbons (HFCs)

HFCs are used as replacements for chloro-fluorocarbons (CFCs) and hydrochloro-fluorocarbons (HCFCs). Unlike the CFCs and the HCFCs, HFCs do not convey chlorine to the stratosphere and thus do not contribute to ozone depletion. According to the 1987 Montreal Protocol and its subsequent amendments, CFCs were largely banned for developed countries after January 1996 (and developing countries after 2010), although some countries have failed to meet the deadline. Furthermore, according to global rules, HCFC usage will be subject to a gradual phase-out with cuts of 35%, 65% and 90% in 2004, 2010 and 2015, respectively. Final HCFC consumption phase-out will occur in 2020 (2040 for developing countries). The main sources of emissions of HFCs are from the uses as refrigerant in cooling and as a blowing agent for insulation foams. The most used HFC is HFC-134a. The mixtures with the names R-401a to R-507a contains various amounts of different HFCs sometimes mixed with HCFCs and hydrocarbons. The weight in tonnes of the emissions of these R-mixtures are therefore not only HFCs. However, in order to calculate the total emissions in CO₂ equivalents, the GWPs shown at the top of the table were used. The GWPs for the mixtures are calculated from the GWP of the individual HFCs in the mixture.

The main emission is from HFC-134a and HFC-404a (containing 44% HFC-125, 4% HFC-134a and 52% HFC-143a). The total emission reaches 0.64 Mt CO₂ in "2010" and only 0.37 Mt CO₂ in "2015".

Perfluorocarbons (PFCs)

PFCs are fully fluorinated hydrocarbons. Because of their extreme long atmospheric lifetimes (2,600 - 50,000 years), they have particularly high GWPs.

The production of aluminum is thought to be the largest source of emissions of the CF₄ and C₂F₆. These emissions are produced primary by the anode effect, which occurs during the reduction of alumina (aluminum oxide) in the primary smelting process, when alumina concentrations become too low in the smelter. Under these conditions, the electrolysis cell voltage increases sharply to a level sufficient for bath electrolysis to replace alumina electrolysis. This causes a high energy loss and a release of fluorine, which combines with the carbon to form CF₄ as well as C₂F₆ in lower quantities. However, there is no primary aluminum production in Denmark. The only source of PFC emission is the use of a small amount of Perflouropropane (C₃F₈) as a component in a cooling liquid in some older cooling installations. Table 1 shows that the emission of PFC (C₃F₈) from Denmark had a maximum of 28 kt CO₂-eq. in 2000 and decreases to 18 kt CO₂ -eq. in "2010" .

Sulphur hexafluoride is an extremely stable atmospheric trace gas. Its unique physico-chemical properties make this gas ideally suited for many specialised industrial applications. Its GWP of 23,900 is the highest of any atmospheric trace gas.

The emissions of SF₆ from Denmark are from three main applications. The largest consumer (60%) is the glass industry, using SF₆ as a sound insulating gas. The second largest consumer is the power plants using SF₆ as an electrical insulation gas. Additionally there is a small consumption (6%) in magnesium foundries, where SF₆ is used to prevent oxidation of molten magnesium and laboratories using the gas.

The time-serie for the emission on SF₆ in Table 16 declines from 107 kt CO₂-eq. in 1995 to 28 kt CO₂ -eq. in 2008 but increases to 107 kt CO₂-eq. in 2012 due to end of life emissions.

Table 16.
Actual emission of HFCs, PFCs and SF₆ from Denmark

Look here!

| Front page | | Contents | | Previous | | Next | | Top |