Approvability Study on Fluidized Bed Combustion Plant Operation Deviating from § 4 (2) of the 17th BImSchV (Federal Immission Control Act)
Project Number 235
Combustion of alternative fuels not being regular fuels as per 1.2 and 8.2a and b of the annex to the 4th BImSchV (Federal Immission Control Act) do gain increasing importance in the power plant area, particularly as co-combustion of biomasses. For these plants, the regulations of the 17th BImSchV do apply. The 17th BImSchV is also applicable for electricity generation from biomass (under consideration of the specifications of the biomass-regulation); this affects an increasing number of power plants.
§ 4 (2) of the 17th BImSchV defines the demands on the combustion conditions regarding minimum temperature, minimum residence time and minimum oxygen content in the combustion phase; they are at least 850 °C for two seconds and six vol.% O2.
Such combustion conditions can hardly be adhered to for fluidized bed combustion plants due to conceptual plant characteristics; they also cause undesirable effects both from the technical and environmental point of view.
The study is to deal with these effects on the basis of the conceptual particularities of fluidized bed combustion plants and thus create the preconditions for the approvability of operation deviating from § 4 (2) (model approval). In here, combustion chamber temperature and residence time of the co-combustion fuels as well as their turbulence characteristics are in the focus of interest (TTT = temperature, time, turbulence).
The project will be realised until end of March 2003, headed by Dr. Tai Nguyen of TÜV Nord GmbH, Hannover. The Working Panel "Fluidised Bed Firing Systems" will support the investigations.