Prediction of Amine Corrosion in Refinery and Gas Processing Rich Amine Circuits Predict-Amine 2.0

23 Pages·2011·1.77 MB·English

Prediction of Amine Corrosion in
Refinery and Gas Processing
Rich Amine Circuits
Predict-Amine 2.0
FFaaiilluurree PPrreevveennttiioonn
Risk Mitigation
Optimized Material Selection
By
Sridhar Srinivasan
Vishal Lagad
PRELMINARY VERSION
Outline
• Introduction to Amine Corrosion
• Overview of Rich Amine Joint Industry Program
• Predict-Amine 2.0: Functionality Description
•• PPrreeddiicctt--AAmmiinnee 22..00:: IInntteerrffaaccee // AApppplliiccaattiioonn
• Questions and Discussion
2
Impact of Amine Corrosion
• Amine units provide gas treating capabilities that remove
acid gases (CO and H S) from feed gas
2 2
• Most piping in amine units built from carbon steel - some
higher alloy utilization in re-boilers and heat exchangers
• There are limited data and guidelines in industry to
quantify amine corrosion with respect to velocity (wall
shear stress) and acid gas loadings
•• DDiiffffeerreenntt aammiinneess aarree uusseedd iinn tthhee iinndduussttrryy wwiitthh vvaarriieedd
operating conditions and limits
• Loss of production in Amine Units
can cost upwards of $400,000 per day
3
Corrosion Problem Areas in Typical Amine Units
TREATED GAS
LEAN AMINE
C
RICH AMINE O
N
ACID
T FILTER GASES
A S
C ACCUM
T
O
R S
T
A
Lean To RR
BB
RRiicchh I
S
Amine
O P
Heat Exch.
R P
B
E
E
SOUR GAS R
R
FEED
Amine
Make-up
4
Amine Corrosion – Overview
• H S and CO from feed gases are absorbed into the amine
2 2
solvent by chemical reaction
• Amines with dissolved CO and H S from the contactor are
2 2
called Rich Amines
• Corrosion in Rich Amine circuits is caused due to
dissolved acid gases and presence of impurities
•• AAcciidd ggaasseess aarree rreemmoovveedd ffrroomm aammiinneess iinn rreeggeenneerraattoorrss aatt
hhiigghh tteemmppeerraattuurree oorr llooww pprreessssuurree
• Amine from regenerator contains low dissolved acid gases
and is called Lean Amine
• Predict-Amine 2.0 focuses on Rich Amine Corrosion
5
Amine JIP Inception
• Absence of quantified data made corrosion prediction /
prevention of failure difficult
• Need for a sound engineering basis to quantify corrosion
in amine systems
• In 2003 Honeywell along with major refiners and gas
processors formed a Joint Industry Program designed to
ggeenneerraattee ddaattaa ffoorr aammiinnee ccoorrrroossiioonn
-
Program sponsored by twelve leading operating companies
• Purpose: To create a definitive, engineering basis for
dealing with amine corrosion for MEA, DEA and DGA®
® DGA is a registered trademark of Huntsman Corporation
6
Corrosion Prediction using Predict-Amine 2.0
• Key Variables for assessing Amine Corrosion
- Acid Gas Loading
- Velocity (Wall Shear Stress)
- Temperature
- Impurities and HSAS
- CO / H S Ratio
2 2
• Types of Amines
- MEA
- DEA
-- DDGGAA
- Phase II of Amine JIP focuses on MDEA
• Materials evaluated
- CS
- 304L
- 316L
- Alloy 2205
- Alloy 825
7
Predict-Amine 2.0
• Incorporates
-
Large database of quantitative corrosion data developed by Amine
JIP from simulated lab tests
-
Flow modeling calculations for wall shear stress
-
Algorithms/rule sets to address effect of the key variables that affect
corrosion
•• PPrreeddiiccttss aammiinnee ccoorrrroossiioonn rraattee ffoorr ffiivvee ((55)) ccoommmmoonnllyy uusseedd
mmaatteerriiaallss iinn MMEEAA,, DDEEAA aanndd DDGGAA sseerrvviicceess
• Provides tools for sensitivity and multipoint analysis
• Provides access to 3D Piping tools for modeling
• Provides secure access to all JIP data, presentations,
trends and correction factors
8
Predict-Amine 2.0: How does it work?
1. Calculate shear stress at pipe wall for process flow
conditions
2. Convert the field shear stress into an equivalent lab flow
loop velocity
33.. UUssiinngg llaabb vveelloocciittyy aanndd aacciidd ggaass llooaaddiinngg,, pprreeddiicctt ccoorrrroossiioonn
rates for all materials using respective iso-corrosion
diagrams developed from JIP DATA
4. Correct corrosion rates for the effect of temperature,
impurities and CO loading based on trends developed
2
from JIP DATA
9
Iso-Corrosion plots in Predict-Amine 2.0
• Ability to predict corrosion rates for all relevant data ranges
• Facilitates easy quantification of amine corrosion
ISOCORROSION DIAGRAM FOR COMBINED AVG CS-CS HAZ
(72 Hour Laboratory Test, 18 wt% MEA, 130 F)
90
65.8
15.6 18.4 25.1
80
> 50 mpy
70
13.2 20 - 50 mpy 42.7
16.1
6600 1199..55
c) < 5 mpy
e 15 - 20 mpy
s
(ft/ 50 5 - 10 mpy
ty 11.5 10 - 15 mpy 14.4 16.5 10 - 15 mpy
ci 40 19.9
o
l 15 - 20 mpy
e 5 - 10 mpy
V
30
20 - 50 mpy
7.5 11.8 11.5 12.0
20 > 50 mpy
< 5 mpy
10
0.2 0.1 1.0 1.3
0
0.0 0.2 0.4 0.6 0.8 1.0
H2S Loading (mole H2S/mole MEA)
Confidential
CONFIDENTIAL
Honeywell –Rich Amine JIP
InterCorr Amine JIP
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