Newsletter and Technical Publications
<Municipal Solid Waste Management>
Regional Overviews and Information Sources
2.3 Topic d: Incineration
European countries vary widely in their reliance on
incineration. Northern European countries, including all of the
"progressive club" of countries and, in this case, Sweden, are highly
reliant on mass-burn incineration, coupled with energy generation, which in
these countries is accompanied by state of the art pollution control equipment.
In Western European countries, it is usually the case that at least 35% and in
some cases as much as 80% of the residential waste stream is disposed of through
incineration. Until relatively recently, this has consisted of reliance on
mass-burn technology, but there is increasing interest in and growing positive
experience with fluidized-bed technologies.
Among other factors, the relative paucity of truly open land has resulted in
a broader social consensus that incineration is necessary than can be found, for
example, in North America. At the same time this consensus has in general also
extended to a strong commitment to pollution control, a commitment which is
strengthened by the proximity of European nations to each other and by their
awareness that they are all at risk for pollution from a neighbor.
Another factor underlying the acceptance of incineration in Europe is that
the energy generated by European waste-to-energy plants goes to supply steam to
district heating loops. The heavy reliance on district heating, and the ready
market for steam that this reliance provides, is part of what makes incineration
so attractive in European cities. Producing steam is more energy-efficient and
more profitable than generating electricity, and contributes to the robustness
of the European waste-to-energy sector. The coupling of incineration with
electricity generation, which contributes substantially to the capital costs of
incineration, is quite rare in Europe, in part because European countries do
not, in general, have utility rate structures that allow non-utility-generated
electricity to be sold to the grid.
Waste incineration is nevertheless often the subject of controversy, usually
because of its air emissions. Waste is a complex combination of substances, and
burning them at high temperatures results in the production of a number of
substances, which are then released from smokestacks to the surrounding air. The
emissions of acid gases, including SOx and NOx, together with heavy metals,
dioxins, and mercury, are some of the sources of concern. Pollution control
equipment on more modern incinerators includes, in most cases, flue gas cleaners
in the form of acid gas scrubbers, together with either electrostatic
precipitators or baghouse filters. Acid gases, SOx, and NOx are removed in flue
gas cleaning systems, which usually consist of either wet or dry scrubbers, or,
as is the case in Sweden, a combination of the two. Heavy metals are more likely
to be removed in post-scrubbing filters, or via the injection of sodium sulfate
in an electrostatic precipitator. This type of pollution control equipment can
also remove dioxins and furans. The European Union is enforcing severe emissions
standards for all types of incinerators, along with rules for protecting the
health and safety of workers.
While accepting their long-term reliance on waste incineration as a disposal
and energy recovery strategy, many European governments are phasing out an older
generation of non-energy-generating incinerators, most of them small and serving
only a single city, because these do not comply with emissions limitations in
national and European Community law. In some cases, these older incinerators are
being upgraded and retrofitted with pollution control equipment.
European countries tend to be well advanced in the utilization of byproducts
of incineration. Fly ash is often used in bonded asphalt and other road
products. The use of bottom ash and slag as an aggregate in road construction or
in the production of brick materials is more common in some countries like the
Netherlands than in others, but has had some setbacks as awareness has grown of
the presence and the leachability of the toxic constituents of these materials.
Where these materials cannot be used, they are generally permitted to be
landfilled in Europe, and not, as in North America, considered to be hazardous
The production of refuse-derived fuel is a second type of energy recovery
system in operation in Europe. A period of enthusiasm for mixed waste sorting in
the early 1970s produced a number of recycling and RDF-producing installations,
mostly of German or Italian design. Many of these facilities were initially
designed to also feed the wet and putrescible wastes into composting systems.
Incinerators in Eastern Europe are often older ones that usually do not have
adequate, or in some cases any, environmental controls. Eastern European cities,
other than major ones, have wastes that cannot be incinerated without auxiliary
fuel. In the context of economic changes that are moving these countries away
from government subsidies of all types, incineration is no longer economically
attractive in some places where it once was deemed to be reasonable.
The Sound Practices section of the Source Book includes a description of the
technologies used in European incinerators: mass-burn facilities, refuse-derived
fuel plants, and fluidized-bed incinerators.