Chemistry in Biomass Combustion
2008-2010
ChemCom 2.0
Åbo Akademi University
Project Introduction (2008-2010)
 Mainly funded by Tekes
 Research Partners
 Åbo Akademi (co-ordinator)
 Helsinki University of Technology
 Tampere University of Technology
 VTT
 Industrial Partners
 Andritz Oy
 Metso Power Oy
 Oy Metsä-Botnia Ab
 Foster Wheeler Energia Oy
 UPM-Kymmene Oyj
 Clyde Bergemann GmbH
 International Paper Inc.
Research Structure (1/2)
Workpackages (9/19)
Biomass
M1: Modelling and validation of recovery boiler measurements
Oxyfuel
conditions
Black Liquor
M2: Modelling and validation of BFB boiler measurements
Waste
M3: Collection and improvement of thermodynamic data for
trace element prediction in combustion and gasification systems
M4: Application specific model development for CFD
Full-scale
measurements
Experiment
Modelling and
validation
Information
I1: Update from the Nordic Graduate School of Biofuel Science
and Technology
I2: Utilisation, developments and up-dating of the ÅA/PCCdatabases
I3: Information on the progress of novel chemical recovery
processes
I4: Oxy-fuel combustion in power boilers fired with solid fuels
and fuel mixtures
I5: National and international collaboration – researcher and
information exchange
F1
E1
E2
M1
I1
F2
E3
E4
M2
I2
F3
E5
E6
M3
I3
M4
I4
F4
I5
Research Structure (2/2)
Workpackages continue.....
Workpackages and responsible research institute
F1: Full-scale measurements; technique development
F2: Full-scale measurements in a recovery boiler:
Pietarsaari, UPM-owner, Andritz built, February 2009
F3: Full-scale measurements in a bubbling FBC;
Rauma, UPM-part owner, Metso built, October 2009
F4: Full scale measurements – treatment of deposits;
method development
E1: High temperature laboratory reactors
ÅA/PCC
F1
F2
F3
F4
E1
E2
E3
E4
E5
E6
E2: Combustion and gasification analysis of black liquor
E3:Combustion, oxyfuel, and gasification analysis of
biofuels and fuel mixtures
E4: Mineral matter and trace elements in biofuels and waste
fuels
E5: High temperature corrosion mechanisms in biomass cofiring, oxyfuel and black liquor combustion/gasification
E6: Laser analytic diagnostics for biomass combustion
M1
M2
M3
M4
I1
I2
I3
I4
I5
TKK
TUT
VTT
Rauman Voima Oy
Campaign program
 Day 1: Bark
 Day 2: Bark+Sludge
 Day 3: Bark+Sludge+REF
Measurement point overview
Gas measurement
Camera
Deposit probe
Suction pyrometer
Laser
Bark+Sludge+REF
Reporting to industrial partners
 Twice a year technical meetings and steering board meetings
 Spring meeting
 Fall meeting

2 - 3 days with different topics each day (totally 20-25
presentations)
 Solid fuels, modelling, corrosion, black liqour, etc.
 Usually about 20 participants from industry
 Totally about 40-50 participants
 www.chemcom.info
on
Power Production & Environment
August 29th - September 3rd 2010
Lapland, Finland
 www.fuelqualityimpacts.org
 fuel.quality@abo.fi
Research Structure (2/2)
Workpackages continue.....
Workpackages and responsible research institute
F1: Full-scale measurements; technique development
F2: Full-scale measurements in a recovery boiler:
Pietarsaari, UPM-owner, Andritz built, February 2009
F3: Full-scale measurements in a bubbling FBC;
Rauma, UPM-part owner, Metso built, October 2009
F4: Full scale measurements – treatment of deposits;
method development
E1: High temperature laboratory reactors
ÅA/PCC
F1
F2
F3
F4
E1
E2
E3
E4
E5
E6
E2: Combustion and gasification analysis of black liquor
E3:Combustion, oxyfuel, and gasification analysis of
biofuels and fuel mixtures
E4: Mineral matter and trace elements in biofuels and waste
fuels
E5: High temperature corrosion mechanisms in biomass cofiring, oxyfuel and black liquor combustion/gasification
E6: Laser analytic diagnostics for biomass combustion
M1
M2
M3
M4
I1
I2
I3
I4
I5
TKK
TUT
VTT
Reactions of pure chromium with
different chlorides
Juho Lehmusto
V Liekkipäivä
14.1.2010
The motives of the study
 Although high temperature chloride
corrosion is a well-known phenomenon,
reasons leading to it are still ambiguous.
 Detailed mechanisms may pave the road
for better control of corrosion.
 Disagreements concerning the roles of
different cations and chlorine.
 Grabke et al., MPIE, Düsseldorf, Germany:
Active oxidation.
 Molecular chlorine
 Doesn’t explain the oxide breakdown.
 Svensson et al., HTCC, CUT, Gothenburg,
Sweden: Two-stage reaction.
1) Oxide breakdown by potassium
2) Direct attack by KCl
 Shinata, MC, AU, Akita, Japan: Two-stage
reaction.
1) Cl- acts as a catalyst
2) Chromate formation determines the magnitude.
Why chromium?
 The capability to form a thin, yet very
dense oxide layer.
Flue gases
Superheater tube
(alloyed steel)
Cr2O3-layer
The effect of KCl
Before
After
Cr-granule with one KCl crystal (0,6 mass-%): 10°Cmin-1 up to 400°C; 2°Cmin-1
up to 700°C; 240 min @ 700°C. Mass growth: 7,1%.
Materials and Methods
-DTA/TG-
 Gives a good general
view about the
possible reaction.
 Presents changes in
mass and heat of
reaction as a function
of temperature and/or
time.
Materials and Methods
2,0
120
1,5
110
DTA
1,0
TG
100
0,5
90
0,0
Exo
80
-0,5
Endo
100
200
300
400
500
o
Temperature / C
600
o
130
Relative mass / %
 Sample is heated up
under controlled
conditions.
 Changes in mass are
detected (TG).
 Other physical and
chemical changes
can also be detected
(DTA).
Temperature difference / C
-DTA/TG-
Test parameters
 Powder samples.
 Constant molar cation
to chromium-ratio.
 400°C, 500°C, 550°C
and 600°C.
Substance
Melting point / °C
Cr
1890
CaCl2•2H2O
772 (anhydr.)
KCl
776
NaCl
801
Heating profiles
20°Cmin-1 → X°C in N2, 60min @ X°C in N2, 120min @ X°C in synthetic air.
800
o
Temperature / C
700
N2
Synthetic air
60 min
120 min
o
500
600 C
o
550 C
o
500 C
400
400 C
600
o
300
200
100
40
80
120
Time / min
160
Chlorides at 550°C
Relative mass / %
130
120
o
550 C
T
110
Gas change
100
Cr (dotted)
Cr + KCl
Cr + NaCl
Cr + CaCl2*2H2O
90
80
40
80
120
Time / min
160
200
Chlorides at 600°C
Relative mass / %
130
o
600 C
T
Gas change
120
110
100
Cr (dotted)
Cr + KCl
Cr + NaCl
Cr + CaCl2*2H2O
90
80
40
80
120
Time / min
160
200
Oxide (Cr2O3) formation
Cr-powder @ 600°C
1 μm
Cr-powder + KCl @ 600°C
1 μm
Chromium with different chlorides @ 600°C
Cr
Cr + KCl
1 μm
1 μm
Cr + NaCl
1 μm
Conclusions
 KCl and NaCl accelerate the corrosion
reaction.
 NaCl and KCl corrosive already far below
their melting points.
Thank You for Your
attention!
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