European Bio-Energy Projects

Expected impact and exploitation
A wider range of waste and biofuels would be
used in existing and new boilers in Europe.
Project results will contribute to achieving the
goals of the Kyoto Protocol as well as to higher
operational reliability, cost savings, less
shutdowns, higher boiler steam properties and
efficiency of power plants. Results will be utilised
in practice for power plant operation, for boiler
design, for defining limits for fuel mixture ratios,
and for heat exchanger material selection.
Progress to date
Characterisation reports from the power plants
used for corrosion tests have been prepared. Two
sets of laboratory-scale combustion tests with
a 40 kW fluidised bed reactor (CFB) have been
carried out. Ashes from filter and cyclone have
been used in laboratory exposures. Preliminary
laboratory tests have been carried on the
oxidation behaviour of the primary alloys selected
for the project. Long- and short-term corrosion
tests have been performed at the Forssa BFBplant,
at the Varkaus CFB-plant and at the
Idbäcken-plant in Nyköping. Co-combustion tests
were performed on the 0.5 MWth pilot furnace.
At this stage few, conclusions can be drawn
from the laboratory experiments:
• Corrosion rate, for the alloys without the
deposit, increases with increasing CO2 content,
especially for the ferritic steels;
• Corrosion rate for samples with the deposit
increase significantly and, in this case, the
internal oxidation of the samples studied was
observed; and
• Cl is not found in the scale and in the deposit
itself after the experiments under usual
conditions.
Figure 1. A deposited superheater in a CFB boiler
(left); deposit probe after a four-week measurement
trial (right).
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Figure 2. SEM images of high-temperature exposure
tests at 600°C. On the left, molydenym oxide with Ca
(sample 10CrMo9 10 covered with cyclone ashes);
on the right, complex oxide, Fe-Mn-O with Ca (sample
X20 CrMoV121 covered with filter ashes).
INFORMATION
References: ENK5-CT-2001-00532
Programme:
FP5 - Energy, Environment and
Sustainable Development
Title:
Mitigation of Formation of Chlorine Rich
Deposits Affecting on Superheater
Corrosion under Co-Combustion
Conditions – CORBI
Duration: 36 months
Contact point:
Markku Orjala
VTT Energy
Tel: +358-1-4672534
Fax: +358-1-4672597
markku.orjala@vtt.fi
Partners:
VTT (FIN)
Vattenfall Utveckling (S)
JRC Petten (INT)
ENEL Produzione (I)
Max-Planck-Institut für Eisenforschung (D)
EC Scientific Officer:
Pierre Dechamps
Tel: +32-2-2956623
Fax: +32-2-2964288
pierre.dechamps@cec.eu.int
Status: Ongoing