Scenarier for øget genanvendelse af dagrenovation
samt vurdering af arbejdsmiljø

Summary

Scenarios
In this note we work with the following 4 scenarios:

• A reference scenario, describing the situation in Denmark in 1996 where the recycling of collected household waste is approx. 15%, excluding household compost.
    

• Two scenarios (scenario 1 and scenario 2) take their starting point in the two goals for increased recycling of organic household waste as described in the upcoming waste management plan from the Danish EPA "Affald 21". The total recycling of organic household waste for scenario 1 and 2 is just under 10% and just above 21% respectively of the total amount of household waste.

In case of increased recycling of organic household waste in relation to the reference scenario, recycling will presumably be in the form of biogasification.

• One scenario (scenario 3), takes its starting point in "Affald 21" and its goals of approx. 60% recycling of paper from households, the equivalent of recycling just under 16% of the total amount household waste.

Tabel: Look here

Total amount of waste divided to 4 scenarios

In the scenarios we operate with the following notions:

• unsorted collection of household waste for incineration
• dual collection of household waste (2 container system for organic waste and rest waste)
• home composting (plan administered by the local authorities)
• collection system at the home address for paper (with container)
• bring banks for paper and glass and/or civic amenity stations.

The reference scenario aims to describe the situation in Denmark in 1996 based on the prevalence of unsorted collection systems, dual collection systems for organic household waste and other waste, home compost arrangements, bring banks for glass, and bring banks/collection at the home address for paper.

Potentials
The paper potentials mentioned in this note all take their starting point in potentials (in absolute amounts) "Survey of paper potentials for private households", Econet, 1998.

Container volume
The assumed container capacity for paper waste described in Work Report nos. 85 and 86, the Danish EPA, 1997, and in this note is approx. 30 litres per household per week.

It is to be expected that there is a correspondence between the available volume and the efficiency of collection.

Environmental implications
The environmental implications of collection and transportation and of the applied types of treatment such as:

• incineration of unsorted household waste
• incineration of rest waste
• biogasification
• composting
• home composting
• recycling of paper

are described in connection with the individual scenarios.

The described environmental data are:

• consumption of subsidiary materials NH₃, lye, lime, filling materials
• residual products for landfilling and recycling
• net energy
• net emissions of NO_x, SO₂, HCl, CO₂, Cd, Pb and NH₃

In addition, we have calculated the free incineration capacity.

Free incineration capacity
When increasing amounts of organic waste and paper are collected for either biogasification or recycling, the amount of remaining waste set for incineration is reduced accordingly. This means a free incineration capacity for scenario 1 and scenario 2 of 300 TJ and 1,000 TJ per year respectively, and of 2,000 TJ per year for scenario 3.

Net energy
The net energy goes up in scenario 1 and scenario 2 by 1% and 2%, respectively, due to the fact that the net energy from biogasification of organic household waste is approx. 10% higher than from incineration.

The net energy for scenario 3 goes up by 14% or 1,700 TJ/year because of the large energy savings gained by recycling paper instead of producing virgin paper.

NO_x emission
The net emission of NO_x corresponds by and large with the net energy results.

SO₂ and CO₂ emissions
The net emissions of SO₂ and CO₂ increase in scenario 1 and scenario 2, due to emissions from biogas engines. The increase in CO₂ emissions has gone from 4% to 13% (13% corresponds to an increase of 31,500 tons/year). The increase is caused by emission of CH₄ from biogas engines, which for CO₂ equivalents should be multiplied by a factor of 25.

By utilising catalysts or afterburning it is possible to reduce the emission of CH₄ to 0 or almost 0. This may, however, effect the efficiency of the biogas engine slightly.

The net emission of SO₂ and CO₂ in scenario 3 has been substantially reduced owing to large energy savings from the recycling of paper.

Emission of heavy metals
The burden from heavy metals - cadmium and lead - is only marginally altered. The change occurs when liquid fertiliser from biogasification is utilised instead of commercial fertiliser.

This brings about a marginal increase in lead emissions and a marginal reduction of the emission of cadmium. The content of cadmium and lead in commercial fertiliser is, however, connected with a considerable amount of uncertainty, and the results should be read accordingly.

Financial implications
The financial implications have been evaluated:

• partly in relation to the implications for the individual household (change in the waste collection fee) in connection with the shift from a system based on collection of unsorted household waste and bring banks arrangements for glass, newspapers, etc. to a system based on dual collection or collection of paper at the home address.
• partly in relation to the implications connected with the reference scenario and the other three scenarios.

Waste collection fee
Depending on the type of household, the waste collection fee for a system based on bring banks and collection of unsorted household waste is estimated at DKK 556-992 a year.

The fee will go up to DKK 607-993 a year if collection of unsorted waste is replaced by dual collection of organic waste and rest waste.

If we only shift from bring bank arrangements for newspapers, etc. to collection at the home address for paper, the waste collection fee, depending of the type of household, will increase by DKK 59-98 a year per household, resulting in a total fee of DKK 654-1,051 a year.

If both dual collection and collection at the home address of paper are implemented, the waste collection fee is estimated to be DKK 705-1,051 a year per household.

Annual costs
The annual costs are calculated as the sum total of:

• annual depreciation and interest payment on waste collection material
• annual costs in connection with collection and transport of household waste
• annual costs of waste treatment

In the reference scenario, the annual costs are estimated at DKK 1,862 million.

The annual costs of scenario 1 are DKK 1,877 million – an increase of 0.8%.

The annual costs of scenario 2 are DKK 1,885 million – an increase of 1.2%.

The annual costs of scenario 3 will see an increase of DKK 128 million, bringing the total to DKK 1,991 million – or an increase of just under 7%.