DEVELOPMENT OF ELECTROCHEMICAL METHOD TO STUDY TOP-OF-THE-LINE CORROSION … · 2017. 12. 22. ·...
Transcript of DEVELOPMENT OF ELECTROCHEMICAL METHOD TO STUDY TOP-OF-THE-LINE CORROSION … · 2017. 12. 22. ·...
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Md Mayeedul Islam
PhD student
Curtin University
DEVELOPMENT OF ELECTROCHEMICAL
METHOD TO STUDY TOP-OF-THE-LINE CORROSION
Content
• Background of study
• Experimental
• Results
• Conclusions
Top-of-the-line Corrosion
Top-of-the-line corrosion (TLC) is the result of temperature gradient between
inside and outside of the pipeline in stratified flow regime
Background of study
QCMER
probe Weight
lossCold finger
probe
TLC monitoring techniques
Advantages
In-situ, operating on mechanism, no
disturbance to specimen, easy to operate
Electrochemical
technique
Challenges
Low volume and conductivity of the
electrolyte, complicated cell arrangement
Objectives
To incorporate electrochemical method for in-situ monitoring
of TLC
To study the interfacial process under a condensed liquid
droplet
Experimental setup
1. Working electrode connection, 2. Counter/reference connection, 3. Thermocouple, 4. Surface temperature
probe, 5. Gas temperature probe, 6. CO2 inlet, 7. Cooling coil for maintaining surface temperature, 8. Polyethylene
terephthalate lid, 9. TLC probe, 10. Condensate collector, 11. 2-L glass vessel, 12. CO2 outlet, 13. Condensate
reservoir, 14. Milli-Q water, 15. Heater
1
2
3
1
3
30
mm
20 mm
2 m
m
1 = Counter electrode
2 = Resin
3 = Working electrode
Ø
12
3
4
5
6 7
8 9
10 11
14
12
13
15
Test Matrix
Parameters Condition
Gas temperature, °C 55
Surface temperature of the sample, °C 20, 30, 40 an 45
Test duration 5 days, 17 days
Bulk liquid Deionized water
Materials Carbon steel
Non-electrochemical method Weight loss, Fe2+measurement
Electrochemical method EFM, LPR and EIS
TLC rate from non-electrochemical method
Fe2+
measurement
1 2 3 4 50.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Corr
osio
n r
ate
(m
m y
-1)
Exposure time (d)
20 C
30 C
40 C
0.2
0.4
0.6
0.8
1.0
1.2
0.4
0.6
0.8
1.0
1.2
1.4
20 30 40
Condensation ra
te (
g m
-2s
-1)
Corr
osio
n r
ate
(m
m y
-1)
Surface temperature (°C)
Weight
loss
TLC rate from electrochemical method
1 2 3 4 50.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Corr
osio
n r
ate
(m
m y
-1)
Exposure time (d)
20 C
30 C
40 C EFM
1 2 3 4 5Exposure time (d)
20 C
30 C
40 C
LPR
TLC rates comparison from different technique
0.0
0.2
0.4
0.6
0.8
1.0
Temperature (°C)
Co
rro
sio
n r
ate
(m
m y
-1)
Wt. loss
Fe2+
EFM
LPR
EIS
20 30 40
Study of the interfacial process
Surface temperature = 45 °C
Gas temperature = 55 °C
Corrosion rate measured by LPR
Active
dissolution
Formation of
porous layer
Formation of
protective layer
Active dissolution (D1-D5)
0 50 100 150 200 250 300
0
50
100
150
200
250
Zim
az (
ohm
.cm
2)
Zreal
(ohm.cm2)
D1
D5
FittedRs R1
Rl
C1
L
Surface image at 3rd day
Formation of porous layer (D6-D13)
0 100 200 300 400 500 600 700 800
0
100
200
300
400
500
600
700
Zim
az (
ohm
.cm
2)
Zreal
(ohm.cm2)
D7
D11
D13
Fitted
Rs
R1
C1
C2
R2
Corrosion product at 6th day
Surface
Cross section
Porous layer
Double layer
Formation of protective layer (D14-D17)
500 1000 1500 2000 2500 3000 3500 4000 4500
0
1000
2000
3000
4000
Zim
az (
oh
m.c
m2)
Zreal
(ohm.cm2)
D14
D15
D16
D17
Fitted
Rs
R2
C2
C3
R3
C1
R1
Surface
Cross section
Corrosion product at 17th day
Outer layer
Inner layer
Double layer
Conclusions
Electrochemical method is successfully applied for online monitoring of
TLC, which gives comparable results with non-electrochemical tests.
Mechanism and growth of corrosion product film can be successfully
explained under a condensing droplet.
The method opens up a new window for investigating the volatile
corrosion inhibitor for mitigating TLC by studying the interfacial process
under condensing condition.
Acknowledgement
• Professor Rolf Gubner
• Dr Thunyaluk Pojtanabuntoeng
• Curtin University for Providing IPRS scholarship
• Curtin Corrosion Centre
THANK YOU FOR YOUR ATTENTION
Question???