Environmental Engineering Reference
In-Depth Information
not until the 1960s that waste incineration really began to show some development. The
prerequisites for this were the district heating networks that began to appear after the Second
World War, when municipalities' interest in district heating was aroused. In 1948, Sweden's
first district heating network was operational in the city of Karlstad and other cities soon
followed. This expansion created opportunities for waste incineration plants, since it provided
an outlet for the heat produced, giving the waste a value. In the 1970s, waste began to be seen
as a resource rather than a problem; in 1975 a proposition from the government stated that
recovery had to increase in the future. The proposition did not state which technology was to
be preferred, but incineration was regarded as preferable in bigger cities. As a result of the
new view of waste as a resource, a number of plants with central sorting and composting were
built. This venture failed since the plants did not work satisfactorily and there was no outlet
for the residual product. This served to increase interest in waste incineration. Waste
incineration expanded significantly, especially during the 1970s, over the years up until 1985.
The number of plants increased from 2 in 1960 to 27 in 1985, and treatment capacity from
100,000 tons annually to 1,800,000 tons. The oil crises of the 1970s led to a growth in interest
in waste incineration as an indigenous fuel, in order to decrease oil dependency.
2
During the
1980s, researchers began to report widespread diffusion of heavy metals and dioxins in the
environment and the effects on humans and animals. Waste incineration was found to be an
important cause of this diffusion of hazardous substances in the environment.
3
In 1985, a ban
on investment in waste incineration was issued by the Swedish Environmental Agency, until
the issues of emissions and technology had been solved. The Environmental Agency and the
Energy Agency were commissioned to analyse the risks associated with waste incineration
and concluded that it was possible to reduce the emissions to acceptable levels through a
number of measures, including “cleaner” waste (i.e. more sorting of waste), more efficient
combustion, advanced flue gas cleaning equipment, and the safe disposal of residual products.
Limits were set for emissions. On the basis of these results, the ban on investment was lifted.
Of the existing plants, 20 went through with modernisations while 7 were shut down.
However, the debate on dioxins in the municipalities did not end there. Hrelja (2006) shows
that in the 1980s the municipality of Skövde chose not to build a waste incineration plant due
to lack of confidence in the treatment method. Later, however, Skövde went ahead and built
the plant, which was inaugurated in 2005.
Waste Incineration in Sweden Today
Today, there are 29 waste incineration facilities in Sweden, both hot water boilers (14)
and combined heat and power plants (15) producing about 8.6 TWh heat and 0.74 TWh
electricity (Swedish Association of Waste Management, 2005b). These facilities treat about
1.95 million tons of municipal waste and 1.2 million tons of other waste, mainly from the
manufacturing industry. Cleaner fractions of waste can also be incinerated at other facilities
and is not included in the figures presented here. Figure 1 shows the waste treatment methods
2
This was only one of a number of measures to decrease oil dependency.
3
There are a number of sources, of which waste incineration is one. Industrial processes can also give raise to
dioxins as can power plants using other fuels. Spontaneous fires at landfills are also a source of dioxins, where
the contribution of emissions is hard to estimate.
