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Prioritisation within The Integrated Product Policy

5 Resource and waste flows

5.1 Introduction to material flow analyses
5.2 Data sources
     5.2.1 Danish resource extraction
     5.2.2 Foreign resource extraction
     5.2.3 Current amounts of deposited and hazardous waste in Denmark
5.3 TMR for Denmark 1999
5.4 Product groups with high material requirements
5.5 Product groups with high amounts of deposited waste in DK

5.1 Introduction to material flow analyses

The Input-Output-tables applied for the prioritisation in Chapter 1 can also be applied for material flow accounts and analyses (MFAs). In fact, the emissions recorded for each industry in the environmentally extended Input-Output-tables, are just one specific type of material flow.

Resources enter the economy through a limited number of industries, notably agriculture, fishery, forestry and mining. From these primary industries, the materials flow into the other industries, where losses occur in the form of wastes and emissions, before the remaining material flows with the products onto the next industry or into final use, where further losses occur.

A material flow analysis may be limited to a specific geographical area and/or a specific time period, or it may apply a product perspective, like the environmental analyses in Chapter 1 (Hinterberger et al. 2003).

When limited to a specific geographical area and/or a specific time period, there will typically be a difference between materials in and out of an industry, i.e. a change in stock. In contrast to this, the product perspective is a steady-state perspective, i.e. all materials entering the economy are traced until they leave the economy again as waste or emissions, even when this takes place at very different places or points in time. Stock changes are only temporary, and for each product, the materials in must equal the materials out. Both primary and secondary materials need to be accounted for in order to make the mass balances complete.

To allow a full material flow analysis, both the input of materials in the form of resources and the output of materials in the form of products, waste or emissions needs to be known for each industry. The amounts of secondary materials supplied and used by each industry must also be known. The difference between materials in and out of an industry is its change in stock.

For the foreign industries, we have not been able to find data on amounts of materials in products and waste, nor on recycled materials or changes in stock. This implies that it has not been possible to trace the input of foreign materials through the economy and thus to identify in which foreign industries they build-up as stock and in which foreign industries they become waste, and how large a share of materials are incorporated in products imported into Denmark.

The Danish import statistics provide us with information on the total weight of products entering Denmark, but it is only possible to identify the material composition for the most homogeneous product groups.

Without having the amount of imported materials as a starting point, it is impossible to establish the total Danish waste potential per material and product, even though it is possible to identify the amounts of specific materials in products and waste at the level of Danish industries from Danmarks Statistik (2003b) and Dall et al. (2003). See also Christensen et al. (2002) for recommendations on improving the data basis for MFA.

Thus, in this chapter, we limit ourselves to prioritising the product groups according to:

• their overall resource use (and thus waste potential) for each type of material input, and
• their contribution to the current amount of deposited waste and hazardous waste in Denmark (i.e. disregarding waste abroad and future waste potentials from materials built into stocks) for each type of material.

We account for the material inputs (both foreign and Danish) divided on the following types:

• Iron
• Aluminium
• Copper
• Other metals
• Coal
• Crude oil and natural gas
• Sand, gravel and stone
• Clay and soil
• Other minerals
• Fibre biomass
• Food biomass (including tobacco)

For these material types, we account for both the amounts extracted for use, and the related unused extraction (mining overburden, unused straw, fish discards etc.). The latter corresponds to the amount of bulk waste in the resource extracting industry. The sum of used and unused extraction is also known as the Total Material Requirement (TMR), see Pedersen (2002).

For the Danish industries and final use, we account for current amounts of deposited waste, divided on the following groups:

• Aluminium
• Copper
• Other metals
• Mineral oil products (asphalt, plastics, waste oil)
• Sand, gravel and stone
• Ceramics and soil
• Other mineral products (gypsum, glass etc.)
• Fibre biomass (including natural rubber)
• Food biomass (as sludge)
• Combustible materials n.e.c.
• Non-combustible materials n.e.c.

Iron, steel, coal slag and ashes, products from flue gas cleaning, bricks and concrete are all regarded as completely recycled and therefore not included under bulk waste in the Danish statistics.

In addition, we account for hazardous waste from Danish industries and final use.

5.2 Data sources

5.2.1 Danish resource extraction

For the Danish resources, we have used the same data sources as Pedersen (2002) for the DMI and TMR for 1997, i.e. the Energy Statistics, Agricultural Statistics and Resource Extraction Statistics from Statistics Denmark. We also applied the same material density conversion factors as applied in the calculation by Pedersen (2002). Our data are therefore basically an update of the DMI and TMR data of Pedersen (2002).

A minor difference compared to Pedersen (2002) is that we did not include aquaculture products as primary resource extraction, as they are mainly fed on fish fodder produced from wild fish, and therefore resemble other animal husbandry products.

The ratios for unused to used resources have also been taken from Pedersen (2002).

5.2.2 Foreign resource extraction

We supplemented the US American NAMEA (Suh 2003) with data for resource extraction based on the USGS data (USGS 2001) for apparent consumption less secondary supplies, and FAOSTAT data on food biomass. This results in resource consumption intensities for each imported product group.

We validated the resulting resource consumption intensities against the weight recorded in Danish import statistics for those commodity groups where the resources occur as relatively pure products, i.e. “Basic ferrous metals, ROW” for iron, “Basic non-ferrous metals, ROW” for the remaining metals, coal, crude oil and natural gas as specific commodities, “Gravel, clay, stone and salt etc., ROW” for minerals, “Forestry products, ROW” for fibre biomass, and “Agriculture, ROW” for food biomass. We found very good correspondence between the import statistics and our calculated values for iron, aluminium, copper, and coal, which are all relatively homogeneous products. Also for food biomass, the correspondence is reasonable (calculated biomass extraction 1.17 E+06 Mg; actual imports 0.90 E+06 Mg), considering the very diverse nature of this product group, which also includes some animals and animal products.

For other metals than Fe, Al and Cu, our calculated values were only ¼ of the actual weight of the Danish imports recorded under “Basic non-ferrous metals, ROW.” This may be explained by the metals imported to Denmark having a different composition than the average composition of non-ferrous metals in the US American economy (metals imported to Denmark generally being more expensive than the average). We therefore corrected the resource extraction for “Other metals” imported under “Basic non-ferrous metals, ROW” with a factor 4. The content of other metals in other imported products were not corrected, since it is reasonable to expect that the average composition of other metals in these products correspond to the US American average.

For resource extraction of crude petroleum and natural gas recorded under “Coal, crude petroleum, natural gas etc., ROW”, a similar correction factor of 0.58 was applied to fit the actual weight of imported oil and gas. Again, this correction was not seen as relevant for the resource extraction of crude petroleum and natural gas for other imported products.

For sand, gravel, stone and clay, the calculated extraction for “Gravel, clay, stone and salt etc., ROW” is more than 4 times the weight of the actual import. It is likely that for such bulk materials, materials that are imported (and thus transported over long distances) are of higher value than the average mineral in the US economy. This is less pronounced for other minerals (chemical and fertiliser minerals) where we see a good correspondence between the calculated values and the actual imported weight. We therefore corrected the resource extraction for sand, gravel, stone and clay for “Gravel, clay, stone and salt etc., ROW” with a factor 0.25. As above, this correction was not seen as relevant for other imported products, where the mineral use must be expected to take place closer to the extraction.

Also for fibre biomass, the calculated biomass resource extraction for “Forestry products, ROW” was larger (1.9 E+06 Mg) than the weight of the actual import (0.7 E+06 Mg), again probably due to the import being of higher value than the average wood in the US economy, which is mainly pulpwood. This is confirmed by the much better correspondence between the calculated and actual values for imports under “Pulp, paper and paper products, ROW” as well as “Textiles, ROW”. We can therefore ascribe the deviations to the inhomogeniety of the fibre resources, and have not made any corrections to the calculated data.

We have applied the same ratios for unused to used resources as Bringezu and Schütz (2001), as reported in the dataset A of Moll et al. (2003). We have used the factors for imports to EU for metals, coal and oil, and the factors for EU for natural gas and minerals. For fish discard, we have applied a factor 0.25. For fibre biomass we have applied a factor 0.2, corresponding to the value used for forest biomass in the calculations by Pedersen (2002). In our calculations, forest biomass constitutes 80-90% of the fibre biomass extraction for imported products, and in view of the above-mentioned large uncertainty on the fibre biomass values, the factor 0.2 has been applied to all fibre biomass, although e.g. the amounts of unused straw is likely to be of the same size as the amount of used straw.

5.2.3 Current amounts of deposited and hazardous waste in Denmark

We have used the Danish Waste Statistics for year 2000 (DEPA 2002) to supplement and correct the information in Dall et al. (2003), where deposited waste is specified for 27 material groups. The resulting values are shown in table 5.1, also showing how these amounts were allocated to the waste supplying industries and final uses.

For hazardous waste to deposits, the dominating sources according to DEPA (2002) were in year 2000: Asbestos dust from repair and maintenance of buildings (8812 Mg), sludge and dust from flue gas cleaning from metal casting (248 Mg), and sludge from metal-hydroxides and –oxides (3611 Mg). The latter are allocated to galvanizing industries based on their expenditure on chemicals for galvanizing (zinc oxides and peroxides, chromium oxides and hydroxides, hydrogen chloride, aluminates, potassium dichromate, hydroxides, ester salts of phosphoric acid, hydrogen fluoride, and sulphuric acid). Other hazardous wastes are not considered.

Table 5.1 Total amounts of deposited waste in Denmark, year 2000

5.3 TMR for Denmark 1999

From the data reported in Chapters 5.2.1 and 5.2.2, we can calculate the TMR for Denmark, as presented in Table 5.2. For easier comparisons, the values are also given in percentages in Table 5.3.

Table 5.2. Total Material Requirement of Denmark 1999 in Mg

Table 5.3. Total Material Requirement of Denmark 1999 in % of column sums

Comparing the results for 1999 to the TMR for 1997 calculated by Pedersen (2002) in Table 5.4, we see a 57% increase in foreign resources extracted for use. Some of this increase is likely to be due to the change in methodology (the 1997 data include only the weight of imported products, while the 1999 data include also resources used in upstream foreign processes), but some of the difference may also be explained by increased imports. It is nevertheless interesting to note that there is not a similar increase in the related unused extraction. All in all, the difference in methodology does not appear to be very important for the overall result.

Table 5.4. Comparison of TMR for 1997 and 1999

5.4 Product groups with high material requirements

From Tables 5.2 and 5.3 it is obvious that the fossil fuels and sand, gravel and stone make the largest contributions to the overall TMR, with biomass as another important group. It is therefore not surprising to find that the product groups with large material requirements (Tables 5.5 and 5.6), are similar to those found in Tables 1.2 and 1.3 for global warming (which is to a large extent governed by the combustion of fossil fuels), mixed with product groups where sand, gravel and stone are major components (the extracting industry exporting these raw materials, and the major consuming industries: construction materials and civil engineering). Food products and horticultural products rank high, both for their consumption of energy carriers and for their biomass extraction.

Table 5.5. Product groups within Danish net production with the largest Total Material Requirement (TMR), in Mg and % of total TMR from Danish production and consumption.

1) The value shown represents the total impact from Danish electricity and heat minus the values for “Electricity (unconstrained)” and “District heat (unconstrained)”

Table 5.6. Product groups within Danish consumption with the largest Total Material Requirement (TMR), in Mg and % of total TMR from Danish production and consumption.

Similar findings appear when looking at product groups with high total material intensity, i.e. parallel to the results in Chapter 1.4.2. Except for the extracting industry “Gravel, clay, stone and salt etc.”, the same product groups as for global warming (see Tables 1.18 and 1.19) dominate the result.

Materials that contribute less to the overall TMR, notably the metals, will obviously not contribute to place product groups high in the ranking in Tables 5.5 and 5.6. Therefore, separate analyses for each material are especially relevant for the metals. As an example of the results that can be provided for each material, using the project database (see Chapter 7), the results for metals are presented in Tables 5.7 and 5.8. It appears that for the major metals (Fe, Al, Cu), it is the same product groups that are have large requirements for the different metals, and even in approximately the same ranking order. This may to some extent be due to the aggregation that occurs in the IO-tables, i.e. in a more disaggregated analysis for specific products it is likely that a larger difference will be found between the requirements for the different metals than what appears from Tables 5.7 and 5.8.

Table 5.7. Product groups within Danish net production with the largest metals requirement in Mg and % of total requirement from Danish production and consumption. The product groups included represent more than 50% of the total requirements for each metal. The data are for extracted metals for use, not including related unused extraction.

However, even at this level of aggregation, it can be seen that iron is used relatively more than the other metals in engines, power plants, machinery in general, construction and civil engineering. Aluminium and copper, on the other hand, is used more in hand tools & packaging, and radio & communication equipment, aluminium also with a larger share in restaurants, while copper has a somewhat lower share in motor vehicles.

Table 5.8. Product groups within Danish consumption with the largest metals requirement in Mg and % of total requirement from Danish production and consumption. The data are for extracted metals for use, not including related unused extraction.

5.5 Product groups with high amounts of deposited waste in DK

From the way deposited waste was allocated to the waste supplying industries and final uses, as reported in Chapter 5.2.3, it is not surprising to find that the main product groups contributing to deposited waste in Denmark are dwellings and repair and maintenance of buildings in general, the sugar industry (due to the soil from beets), sewage treatment (sand, fibres and food biomass), and civil engineering (mainly removed soil). Thus, for waste, the product-oriented approach does not provide substantially more relevant information than already provided by the waste statistics.

However, it may be interesting to use the project database (see Chapter 7) to investigate the source of specific types of waste. As an example of this, we show in Tables 5.9 and 5.10 the product groups contributing to deposited copper waste in Denmark. Since marine engines, compressors, hand tools, packaging etc., which contribute most to the deposited copper waste, are not products that contribute much to Danish private and public consumption (they are nearly all exported), Tables 5.9 and 5.10 look quite different. Dwellings is the first product group, while most of the copper waste in following product groups in Table 5.10 can be traced back to their input of marine engines, compressors etc. For the product groups in private consumption, the dominating source is copper in hand tools etc.

Table 5.9. Product groups within Danish net production with the largest contribution to deposited copper waste in Denmark, in Mg and % of total deposited copper waste in Denmark from Danish production and consumption.

Table 5.10. Product groups within Danish consumption with the largest contribution to deposited copper waste in Denmark, in Mg and % of total deposited copper waste in Denmark from Danish production and consumption.

It is interesting to note that there is a good correspondence between the product groups in Table 5.9 (deposited copper waste) and those for copper requirement in table 5.7. A similar correspondence is found between most of the product groups in Table 5.10 and those for copper requirement in Table 5.8. A notable exception is copper in automobiles, topping the list in Table 5.8 but apparently not contributing to deposited copper waste according to Table 5.10. This may point to a better separation of copper during waste treatment of automobiles, but may also be an artefact from the allocation of deposited copper waste, which is done exclusively over the industries supplying commodity V740400 Copper waste. It has not been possible within this project to investigate this further.

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Version 1.0 February 2005, © Danish Environmental Protection Agency