1. No category

The Mechanisms of Corrosion –
and how to avoid it them?
Dr.-Ing. Ragnar Warnecke, GKS, Schweinfurt
Dr. rer. nat. Bernd Benker, CUTEC, Clausthal-Zellerfeld
Dipl. Phys. Christian Deuerling, GKS, Schweinfurt
Prof. Dr. Ferdinand Haider, Univ. Augsburg, Augsburg
Prof. Dr. Siegried Horn, Univ. Augsburg, Augsburg
Dr. Jürgen Maguhn, GSF, Neuherberg
Dipl.-Ing. Volker Müller, GKS, Schweinfurt
Dipl. Chem. Hermann Nordsieck, BIfA, Augsburg
Dipl. Phys. Barbara Waldmann, Univ. Augsburg, Augsburg
Prof. Dr. Ralf Zimmermann, GSF, Neuherberg
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
Content
Introduction!
Understanding?
Solution?
Summary / Perspective!
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
2
1. Introduction
GKS = Coal-, Gas and WtE-CHP-Plant
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
3
Flow Chart of GKS GmbH
C-CHPP Steam Parameters:
115 bars; 535 °C
WtE-CHPP Steam Parameters:
65 bars; 435 °C
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
4
Availability = Economy
1
6
11
16
21
26
31
36
41
46
51
56
61
66
71
76
81
86
91
96 101 106 111 116 121 126 131
-2,00
-4,00
2. Zug
vor ÜH 5
-6,00
vor ÜH 6
vor ÜH 4
vor ÜH 3
-8,00
vor ÜH 2
vor Eco
Kesselende
-10,00
95
-12,00
85
75
-14,00
65
Zeit [Tage]
55
t/h
Deposits 45
mm
Druckdifferenz [mbar]
Feuerraum
35
25
15
5
Corrosion -5
25.09.2007
13:55:12
25.09.2007
14:02:24
25.09.2007
14:09:36
25.09.2007
14:16:48
25.09.2007
14:24:00
25.09.2007
14:31:12
25.09.2007
14:38:24
25.09.2007
14:45:36
25.09.2007
14:52:48
25.09.2007
15:00:00
25.09.2007
15:07:12
Zeit
SPW Menge 13LAB20CF301.ZQ01
FD Menge 13LBA10CF901.ZQ01
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
Trommelniveau 13HAD01CL302.XQ01
5
Extended Corrosion Diagram - WtE
Extended corrosion
Diagram
[Warnecke, 2003]
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
6
2. Understanding?
HTCl-Corrosion
H2O- /
Tubeside
Red Layer:
Mainly Cl and Fe
(FeCl2)
Thickness:
~ 100 – 250 μm
Alkali- and Earthalkali chlorides
Alkali- and Earthalkali sulfates
Green Layer:
Mainly S and
Fe (FeS2)
Thickness:
~ 100 – 200 μm
Blue Layer:
Mainly O und
Fe (Fe2O3 )
Thickness:
~ 800 – 1200 μm
Deposits-/
Flue gas side
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
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7
Examples for Coupling CFD and TEC
GKS-WtE-Boiler:
Used Programs:
CFX and FactSage
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
8
300 °C
Boiler wall
DilutionAir PTD
“Button hook”
Curved Inlet
Porous tube
diluter
Cyclone
Isokinet.
Divider
Inletnozzle
Cyclone
Drying
Ejector diluter
Dilution air
Ejector diluter
Raw gas
Condensation
Sampling
Volume
Flow
Meas.
Pump
Partikel analysis
Analysis
Gas analysis
Mas.%:
ELPI – Online (30nm-10m)
65 %
APS - Online (800nm-20m)
25 %
10 %
Cyclone (>20m)
Inlet curve
Berner-Low pressure-Impactor (<62nm - 10m)
10nm
100nm
1m
10m
100m
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
1mm
9
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
10
Discrepancy: Calculation - Measurement
Calculation with FactSage: Main species at 600°C
0%
20%
40%
60%
80%
Measurement, identified Species at 600 °C;
2. Pass
100%
20%
15%
10%
5%
0%
SiO2
SiO2
ZnAl2O4(s)
ZnAl2O4(s)
ZnCl2(g)
ZnCl2(g)
K2ZnCl4
K2ZnCl4
K3OCl
K3OCl
KCl(Mischph.)
KCl(Mischph.)
KCl(g)
KCl(g)
K, NaCl
K, NaCl
NaCl(Mischph.)
NaCl(Mischph.)
K2SO4(Mischph.)
K2SO4(Mischph.)
K3Na(SO4)2
K3Na(SO4)2
Na2SO4(Mischph.)
Na2SO4(Mischph.)
CaSO4(Mischph.)
CaSO4(Mischph.)
Ca5HO13P3(s)
Ca5HO13P3(s)
KAlSi2O6(s)
KAlSi2O6(s)
PbCl2(g)
PbCl2(g)
Fe2O3(s)
Fe2O3(s)
Mn2O3(s)
Mn2O3(s)
NiO(s)
NiO(s)
Mg2SiO4(s)
Mg2SiO4(s)
CrSO4(Mischph.)
CrSO4(Mischph.)
CrCl2(Mischph.)
CrCl2(Mischph.)
(CuCl)3(g)
(CuCl)3(g)
(CuO)(Fe2O3)(s2)
(CuO)(Fe2O3)(s2)
CaTiO3(s)
CaTiO3(s)
V2O5(s)
V2O5(s)
CuBr3(g)
CuBr3(g)
amorph
amorph
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This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
11
Massenkonzentration
Mass concentration
[g/m3] [g/m_]
Normal Operation:
Particle Distribution
0.1
0.01
0.001
0.0001
0.01
0.1
1
10
100
1000
10000
Partikelgröße [m]
Average of 3 - 8 Measurements
Z1
Aerodynamic particle diameter [m]
Z1 Trend
Z2
Z2 Trend
Z3
Z3 Trend
Z4
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This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
Z4 Trend
12
Normal operation:
Chemical Composition of Particles – 3 Summed Fractions
Mittlere Zusammensetzung Zug 2
Average Composition Pass 2
Mittlere
Zusammensetzung
Zug
Average
Composition Pass
11
100%
100%
90%
90%
80%
80%
Rest
70%
Rest
70%
Cl
S
50%
Pb
40%
Zn
Cl
60%
Anteil
Ratio
Anteil
Ratio
60%
K
30%
S
50%
Pb
40%
Zn
K
30%
Na
Na
20%
20%
Ca
10%
Ca
10%
Si
Si
0%
0%
< 1m
1-20m
< 1m
> 20m
1-20m
Coarse fraction:
Primary particle
(Ca, Si)
• Ca-high
• “Balance" increasing
> 20m
Particle
Fraction
Partikelfraktion
Partikelfraktion
Particle
Fraction
Mittlere
Zusammensetzung
Zug4 4
Average
Composition Pass
Mittlere
Zusammensetzung
Zug33
Average
Composition Pass
100%
100%
90%
90%
80%
80%
Rest
70%
Rest
70%
Cl
S
50%
Pb
40%
Zn
K
30%
Cl
60%
Anteil
Ratio
60%
Anteil
Ratio
Fine fraction:
Secondary particle
(Na, K, Cl)
• Cl-high,
decreasing
• S-low,
partially increasing
S
50%
Pb
40%
Zn
K
30%
Na
20%
Ca
10%
Si
0%
Na
20%
Ca
10%
Si
0%
< 1m
1-20m
Particle
Fraction
Partikelfraktion
> 20m
< 1m
1-20m
> 20m
Partikelfraktion
Particle
Fraction
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
13
Normal Operation:
(De-)Sulphidation
Particle-phase (< 0,2 m):
HCl
SO2
60
Chemical equivalents (HCl; S/2)
[Mol/kg]
Chemical equivalents (HCl; SO2 /2
[mMol/m_ STP]
Gas-phase:
14
Cl
S
12
50
10
40
8
30
6
20
4
10
2
0
0
1st
pass
2nd
pass
BE
519 n2
519 n2
519 n2
pass
2nd
pass
BE
1st
pass
2nd
pass
1st
pass
2nd
pass
1st
pass
519 n3
519 n3
519 n3
518 n1
518 n1
519 n2
519 n2
519 n3
1st
2nd
pass
519 n3
BE = Boiler End
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14
Corrosion Sensor
Water cooled lance
Air cooed sensor head
Electrical contacts for measurement
Ceramic rings
Air Inlet
Material Probes
Water Fitting
Total Length ca. 3 m
Fittings for Thermocouples
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This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
15
Comparison: Plant Tubes vs. Sensor
Example:
3 months plant tubes:
Tube
3 months sensor rings:
Tube
FeaClb
FecSd
FeeOf
Alkali-Cl
Alkali-S
Identical Structure of Tube and Sensor!
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
16
Layer Thickness [m]
Thickness of Layers
Iron Oxid
Tube Reduction
Iron Chorine
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17
Correlation: Wall decline vs.
Ceramic rings
Corr.-signal
Probe of 15Mo3
(a) free corrosion potential
Ring 1: 15Mo3
Ring 2: Inconel
Ring 3: 15Mo3
U
(b) power-voltage-line
Ring 1: 15Mo3
Ring 2: Inconel
Ring 3: 15Mo3
I
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
18
Sensor data – systematic temperature
variation
Corrosion conductance is depending exponentially on temperature
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
19
FeCl3(g)
Reactions at boundary layers
O2, HCl, Cl2
• 15Mo3/FeCl2 :
O2
2 FeCl3 + Fe 3FeCl2
Cl2
•FeCl2/FexOy:
FexOy+MClx+MSOy
Cl2
FeCl3(g) Gas
transport
4 FeCl2 + 3O2 2 Fe2O3 + 4Cl2
2 FeCl2 + Cl2 2 Fe Cl3
FexOy
FeCl3
FexOy
Cl2 FeCl2
•Fe2O3/Fe3O4:
FexOy
FeCl2+x
FeCl2
Ion
transport
15Mo3
4 FeCl3 + 3O2 2 Fe2O3 + 6Cl2
6 FeCl3 + 4O2 2 Fe3O4 + 9Cl2
Metal chlorine
Metal sulfate
(not complete
until now!)
2 NaCl ,2 KCl , CaCl2 + 3SO2 + 3O2 Na2 SO4 , K 2 SO4 , CaSO4 + 3Cl2
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
20
NextGenBioWaste
EFRE-KORR
Distant Range
Comb. Ch.
calcination
Close-up Range
changes during flight
fouling/tube
approach to border
outer layer
active layer
Stokes
550°C
>500m
combustible
+++
middle
Y+
+
Impaction
400°C
Chem.
sulphation
Physics
Diffusion
surface d.
coarse
X
Chem.
adhesion
Physics
gas d.
Chem.
agglomeration
"slagparticle"
condensation
grate
slag
sedimentation
Physics
particle
foulinganalogy
800°C
transport
to border
1050°C
sulphation
1200°C
FexOy
barrier
STOP
Cl (-)
S (+)
?
?
?
?
Cl –
S+
?
Cl –
S+
+
coarse
(>20)
++
small (<1)
anorg.
S / Cl
Impaction
Thermophoresis
Interception
+
STOP
condensable
matter (salts,
metals, etc.)
grate
Cl –
S+
small
z-
(+)
Thermophoresis
Turbophoresis
?
+++
org.
S / Cl
Cl ?
S?
2 FeCl2 + [Cl] 2 FeCl3
2 FeCl3 + Fe 3 FeCl2
STOP
Condensable
Salts ?
combustion
chamber (S/Cl)
corrosion of tube
STOP
middle
(1<x<20)
chloride, gaseous
no
vapor
pressure
Fe2O3 + Fe 3 FeO
[Cl]
HCl
HCl +
HCl
yes
yes
HCl ++
SOx
SOx -
SOx
yes
yes
SOx--
grate system
air system
plant
Rest
(O2,
H2O, ...)
Rest
O2, H2O, ...
1st pass
2nd pass
yes
3rd pass
yes
e.g.
FeS, FeOx
O2 –
H2O --
Super heater
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
21
How to avoid HT-Chlorine-Corrosion?
At superheater:
Chlorine Trap
HWS
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22
Crossover 2./3. Pass: Chlorine Trap
Actual situation:
3 vaporiser tubes (distance:
400 mm)
Future condition:
T=180
(distance: 100 mm)
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
23
HWS
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
24
HWS – Effect of Cleaning
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This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
25
Adding Sulphur
Direct sulphur and SO2
Schwefelpellets, Mittelwerte, Vgl. m. Normalbetrieb 060801
10
Mittlere Zusammensetzung Zug 3
S-pellets (30,18 kg/h) - Mittl. Zus.-setzung Zug 3
Massenkonzentration [g/m?]
1
0.1
0.01
0.001
0.0001
100%
100%
90%
90%
80%
80%
70%
70%
60%
60%
50%
50%
Pb
40%
40%
Zn
30%
30%
20%
20%
10%
10%
0.00001
0.01
0.1
1
10
100
1000
10000
Partikelgröße [m]
Z2, SP, Mittelwert
Z3, SP, Mittelwert
Z2, NB, 060801
Z3, NB, 060801
Rest
Anteil
Cl
S
K
Na
Ca
Si
0%
0%
< 1m
1-20m
Partikelfraktion
> 20m
< 1m
1-20m
> 20m
Partikelfraktion
Increasing of sulphur content, without reducing chlorine
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
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26
4. Summary / Perspective
Boiler influences Gas/Aerosol within FG way
Chlorine layered large particles depositing by impaction
Interaction between flue gas and particles: sulphidation with
release of chlor(ine) in the deposits
Chlorine trap shall catch chlorides before SH
Attack of chlorine should be modified by using
process know-how or depositing protection layers
Next step: Better understanding of chlorine formation in the
combustion chamber (NGBW)
ISWA -Beacon-Conference, 25.-26. October 2007, Malmö
This Project was co-financed by the Baverian Ministery for Environment, Health and Consumer Protection within the European Regional Development Fund (ERDF)
27