SO - Rheinkalk

Thermal waste treatment plants
At the beginning of the 1990s retrofitting or construction of flue-gas cleaning plants
was initiated for municipal waste and hazardous waste incineration plants (MWI /
HWI). The driving force for this was the 17th BImSchV in Germany which was nearly
completely transferred to European legislation, which moreover also affected other
industrial fields.
Important objectives in this respect include high efficiencies in the removal of HCl
and SO2 in addition to the already much-discussed ecotoxic pollutants. In order to
meet the mandatory objectives, very complicated wet processes were installed in the
first phase while some operators used retrofitting or upgrading existing semi-dry or
dry processes. The installation of the MCD process proved to be a successful
measure for the cost-effective compliance with the 17th BImSchV. The various
methods include combinations of spray sorption and dry sorption as well as a
combination of two dry sorption steps. Of considerable importance for this is the use
of a highly reactive Spongiacal ® product in the dry sorption stage. The application of
mixed adsorbents is widely used to reduce ecotoxic pollutants.
SO2-separation [%]
100
80
60
40
20
0
Schematic description of the MKT-process
one stage spray
dry sorption
Stoichiometric ratio
savings ~ 30 - 50 %
0,0 1,0 2,0 3,0 4,0
Stoichiometric ratio [-]
Graph 5: Description of the MCD process (Two-Stage-Process)
The operating temperatures of the dry sorption stages have recently been used to
optimise operational processes. The temperatures in the fabric filter stage usually lie
between 150 °C and 190 °C. Current investigations have also been carried out at
220 °C.
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