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polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), as well as
other emission products, have raised much concern. Unfortunately, information
presented to the public about health risks of incineration is often incomplete, includ-
ing only data on PCDD/Fs levels in stack gas samples (Domingo et al., 1999). In
order to get overall information on the environmental impact of a municipal solid
waste incinerator (MSWI), a wider study must be performed. Next we present and
analyze the case of an MSWI in Tarragona, Spain. This case study is presented with
three different alternatives explained below.

1.7.2 MUNICIPAL SOLID WASTE INCINERATOR (MSWI)
IN TARRAGONA, SPAIN
Our case study will focus on an MSWI (SIRUSA) located in Tarragona (northeastern
Spain) that has operated since 1991. In 1997 an advanced acid gas removal system
was installed. Thus, two situations (or scenarios) were studied: the operation of the
plant during 1996 (later called former situation or scenario 1) and the current oper-
ation with the advanced acid gas removal system working (later called current
situation or scenario 2).
The incinerator has parallel grate-fired furnaces with primary and secondary
chambers. The combustion process is based on Deutsche Babcock Anlagen technol-
ogy. Each of the furnaces has a capacity of 9.6 tons per hour, which makes
approximately 460 tons daily incineration capacity of municipal waste. The temper-
ature in the first combustion chamber varies between 950 and 1000∞C. In the
secondary postcombustion chamber, the temperature is 650 to 720∞C and the output
temperature of the flue gas is 230 to 250∞C. The minimum incineration conditions
are 2 s of incineration time at 850∞C with 6% minimum oxygen excess. The com-
bustion process is controlled by on-line measurements (CO , O ) and visually with
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2
the help of TV monitors (Nadal, 1999). The process generates electricity of the
steam at a rate of 44.8 tons per hour. About 80% of the total electricity produced is
sold and 20% is used for the operation. The scrap metal is collected separately and
iron is recycled (STQ, 1998). The incinerated residues are solids. The average
composition of the municipal waste is shown in Table 1.1 and a schematic overview
of the plant is given in Figure 1.9.
The flue gas cleaning process is a semidry process consisting of an absorber of
Danish technology (GSA). The acid compounds of the flue gas, such as HCl, HF,
SO , are neutralized with lime, Ca(OH) . The reaction products are separated in a
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2
cyclone and after that the gases are treated with injected active carbon to reduce
dioxin and furan concentrations. The last cleaning step, a bag filter house, ensures
that the total emissions meet the legislative emission limits: Spanish RD 1088/92
Directive and also a regional Catalan Directive 323/1994, which is an improved
version of the European 89/369/CEE Directive. The total emissions and other process
data are presented in Table 1.2.
The emissions are also controlled by the local authorities (Delegació Territorial
del Departament de Medi Ambient de la Generalitat de Catalunya.). Thus, the plant
is under continuous, real-time control, which guarantees independent information
on the emissions.

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