Report on CO2 Stripper

1. 2011
CO2 STRIPPER
(T-1101)
Problems, Solutions & Suggestions
Report contains stripper history in detail and advanced
technologies introduced for stripper tubing. Style of report is
absolutely different from traditional styles as it gives an
excellent & immediate review of stripper.
SYED ETIZAZ HASSAN
U.E.T LAHORE
8/25/2011

2. [T-1101] [INTERNSHIP 2011]
APPROVALS
SUPERVISOR
(Mr. Abdul Hakim )
MENTOR
(Mr. Azhar Rasool)
GL
(Mr. Qamar Jaleel)
ENGRO FERTILIZERS Page 2

3. [T-1101] [INTERNSHIP 2011]
CONTENTS
x CO2 STRIPPER
x HISTORY OF CO2 STRIPPER(TURN AROUNDS)
x T/A 2009 ,AN EXAMPLE
x CURRENT ISSUES
x SOLUTIONS SUGGESTED
I. TUBES
II. TUBESHEETS
III. DISTRIBUTION TRAY
IV. SWIRLS
GASKETS
V.
x T/A 2012
x PREVENTIVE MEASURES
x MY SUGGESTIONS
WHAT I HAVE LEARNT?????
What I DID FOR ALL OF IT????
THINGS IMPRESSED ME HERE @ ENGRO
ENGRO FERTILIZERS Page 3

4. [T-1101] [INTERNSHIP 2011]
T-1101 in ACES
• A ADVANCE
• C COST
• E ENERGY
• S SAVING
T-1101 Installation
(October-1998)
ENGRO FERTILIZERS Page 4

5. [T-1101] [INTERNSHIP 2011]
ENGRO FERTILIZERS Page 5

6. [T-1101] [INTERNSHIP 2011]
CO2 STRIPPER (UREA STRIPPER T-1101)
Stripper in ACES synthesis loop consists of tray part and stripping
part with vertical tubes. The solution from Reactor is fed to tray
part contacting with mixed gas from stripping part. NH3 and CO2
molar ratio is reduced from 4.0 to 3.0 at tray part to achieve
suitable composition for CO2 stripping. Solution from side down
comer of tray part enters on distribution plate. At the
distribution plate, solution is distributed on tube sheet through
holes of distribution plate equally with keeping liquid level
around 100-200mm on the distribution plate.
On the tube sheet, the solution makes liquid level higher than
swirl’s holes by 60-70mm. And the solution enters to swirls’ holes
tangentially to make uniform thin falling film on the internal
surface of tube. CO2 gas introduced at the bottom of tubes as
stripping medium contacts with the solution in the tubes under
the falling film condition. The solution is heated from tube
outside by 20kg/cm2g steam during contacting with CO2 gas.
Carbamate is decomposed and NH3 is removed and separated
from the solution by CO2 gas under the high-pressure condition.
Finally, NH3 content in the solution from the bottom of Stripper
is reduced to 13-14%.
ENGRO FERTILIZERS Page 6

7. [T-1101] [INTERNSHIP 2011]
T-1101 Design by Toyo Engineering
SHELL SIDE
 Operating Temperature
417°F(214 °C)
 Design Temperature
464°F(240 °C)
 Operating Pressure
284 psig
 Design Pressure
355 psig
TUBE SIDE
 Operating Temperature
356°F/374°F(179/190°C)
 Design Temperature
428°F(220 °C)
 Operating Pressure
2490 psig
 Design Pressure
2613 psig
ENGRO FERTILIZERS Page 7

8. [T-1101] [INTERNSHIP 2011]
METALLURGY
Outer Shell CS Tube DP-12
Internal Lining DP-12 Sieve Tray DP-12
Distribution Tray DP-12 Swirl DP-12, SUS-329, J4L, DP28W
Stay Rod DP-12 Gasket Tombo 9007-SC & Comp Graph
IMPORTANT DATA
Internal diameter top 2600 mm Length top 3060 mm
Internal diameter middle 2500 mm Length after tubes 1000 mm
Tube Length 5963 mm Length bottom 900 mm
No. of Tubes 3100 diameter of Tube 31.8 mm
Thickness of tube 2.9 mm Weep Holes 69
Number of Trays 3 No. of holes per tray 4508
Lining thickness 6mm Corrosion allowance 1.5 mm (tube)
Weight of shell 197000 kg
ENGRO FERTILIZERS Page 8

9. [T-1101] [INTERNSHIP 2011]
HISTORY of T-1101
TURN AROUNDS’ SCHEDULE
1 TURN AROUND 2000(MARCH)
2 TURN AROUND 2001(APRIL)
3 TURN AROUND 2002(OCTOBER 15)
4 TURN AROUND 2004(MARCH-APRIL)
5 TURN AROUND 2005(APRIL)
6 FORCED OUTAGE 2006(OCTOBER)
7 TURN AROUND 2009(MARCH)
ENGRO FERTILIZERS Page 9

10. [T-1101] [INTERNSHIP 2011]
T/A 2000
 10 % swirls were swinging & loose
 Uneven liquid level on distribution plate
 Seal weld leakage testing
ENGRO FERTILIZERS Page 10

11. [T-1101] [INTERNSHIP 2011]
T/A 2001
 High bottom temperaturev
 100% ECT
 Short circulation of liquid from bottom tray
 Bottom tray sagging
 ‘o’ rings damaged
 All the swirls were swinging
 Stay rods damaged
T/A 2002
 Swirls inspection
 33% ECT
 IPRL arrange adequate inventory of stay rods
 IPRL plan repair /replacement of swirls based on
TOYO analysis
 Steam side PSV flange gasket replacement
 Distribution holes on the distribution plate had been
enlarged
 Sample point valves relocation required
ENGRO FERTILIZERS Page 11

12. [T-1101] [INTERNSHIP 2011]
T/A 2004
 Lube oil filters Replacement
 Swirls holes diameter increased from 2.8 mm to 3.1
mm
 60 % ECT
 Gaskets and swirl "o" rings damaged
 Stay rod damaged
 Bare wire for welding (Pak American)
 Bottom temp raised to 192 deg C
 Ammonia concentration raised to 21.19 %(NH3
rec. system overloaded )and NH3 vapors increased
to 50%
 Distribution holes on the distribution plate have
been enlarged
ENGRO FERTILIZERS Page 12

13. [T-1101] [INTERNSHIP 2011]
T/A 2005
 Tube and tube sheet seal welds leakage
 ‘o’ rings damaged
 Gaskets of steam inlet and outlet valves damaged
FORCED OUTAGE 2006
 Tubes leakage was detected
 Tube sheet inspection
 Swirls hole diameter increment
 Swirl guards damaged
 2.8 % ECT
ENGRO FERTILIZERS Page 13

14. [T-1101] [INTERNSHIP 2011]
T/A 2009
 Thermo well corroded
 Swirls destroyed
 Vessel liner inspection
required
 Gaskets for manhole to be
replaced
 Swirls 'o' rings damaged
 Soft gaskets for swirls
 Washers for stay rod
 Seal welds damaged
 Distribution plate hole
diameter increased 129%
 Chest side bleeder valve is leak
thru
 Condensate outlet sample point valve glands repacking required
 Steam inlet sample point valve glanding required
ENGRO FERTILIZERS Page 14

15. [T-1101] [INTERNSHIP 2011]
OUTCOME OF T/As
T/A 2009 AN EXAMPLE
Efficiency BEFORE & AFTER t/a 2009
ENGRO FERTILIZERS Page 15

16. [T-1101] [INTERNSHIP 2011]
SWIRLS REPLACEMENT
350
300
250
200
New 2009
150 Old 2005-2006
100
50
0
Segment Segment Segment Segment Segment Segment Segment Segment Segment Segment
#1 #2 #3 #4 #5 #6 #7 #8 #9 # 10
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17. [T-1101] [INTERNSHIP 2011]
DISTRIBUTION PLATE HOLE DIMENSIONS
ENGRO FERTILIZERS Page 17

18. [T-1101] [INTERNSHIP 2011]
CURRENT ISSUES
ISSUES FORESEEN (HISTORY BASED)
 High bottom temperature
 Swirl's hole diameter increment
 Swirl/stay rod gasket & 'o' ring damaged
 Swirls’ guard damage
 Tubes leakage( CS lines corrosion)
 Swirls, tubes and shell corrosion
 Spurger holes diameter increment
 Carbamate condenses on the level transmitters
 Vortex breaker corroded
 Sieve trays gasket leakage
ENGRO FERTILIZERS Page 18

19. [T-1101] [INTERNSHIP 2011]
ALARMING ISSUES
 Stripper efficiency dropped 2 %(02 /02/2011)
 Decreasing tube thickness (TOYO report in 2006)
 Distribution plate holes diameter increment
 Weep holes
 Seal welds leakages
 Carbamate leakage at bottom may way
 Corrosion & erosion
ENGRO FERTILIZERS Page 19

20. [T-1101] [INTERNSHIP 2011]
SOLUTIONS SUGGESTED
TUBES
 Proper adjustment of swirls
 High pressure & temperature (non chloride)steam cleaning
 Welding at lower temperature
 ECT of 100% tubes
 Tubes plugging
ENGRO FERTILIZERS Page 20

21. [T-1101] [INTERNSHIP 2011]
TUBE SHEET
 Arrangements for proper seal welding of tubes
 Distribution plate laser leveling
 Efficient grinding of seal welds
DISTRIBUTION PLATE
 Proper adjustment of swirl guards and stay
rods’ gaskets
 Proper bolting with shell
 Plugging
 Change it(as in 2004)
SIEVE TRAYS
 Gasket replacement
 Level maintenance
ENGRO FERTILIZERS Page 21

22. [T-1101] [INTERNSHIP 2011]
SWIRLS
 Installation procedure
 ‘O’ rings replacement
 2-passes seal welds
 Gaskets for swirl guards
 Proper adjustments for distribution plate leveling
 Proper hole testing (specially for swirls of 2004-05)
 Buy some new swirls (as swirls replaced in
2004-05 may destroyed)
GASKETS
 Gaskets at inlets & outlets
 ‘O’ rings Teflon gaskets (tombo T #2090)
 Black gasket (Tombo #9007-SC)
 Soft gasket (Tombo T #9096)
 Man way gaskets
 Sieve trays gaskets
ENGRO FERTILIZERS Page 22

23. [T-1101] [INTERNSHIP 2011]
T/A 2012 (CO2 STRIPPER) PLAN
ENGRO FERTILIZERS Page 23

24. [T-1101] [INTERNSHIP 2011]
PREVENTIVE MEASURES
 New swirls purchase
 Tombo sheets for gaskets and 'o' rings
 Stay rods replacement required
 Bare wire DP 3T
 Prepare for 100 % ECT
 Man holes gaskets replacement
 Weep holes cleaning and lining judgment
 Proper arrangement for seal welder & seal weld cutter
 Proper testing of methyl red solution for weep hole testing
 UT for shell lining
 Distribution plate needed to be replaced
ENGRO FERTILIZERS Page 24

25. [T-1101] [INTERNSHIP 2011]
MY SUGGESTIONS
 Tubes replacement (FFC)
 2RE69(Cr & Ni ) by Sand vick
 Zr layering Omega Bond technology (ATI Wah
Chang) (waiting for quotation)
 Seal welding machine & grinder (Ar cooling)
 Distributor plate plugging and boring more holes
 Thermo vision of stripper lines
 ECT report should be sent to TOYO
 Experienced persons’ involvement in T/A s
 A/C cooling during shutdown
ENGRO FERTILIZERS Page 25

26. [T-1101] [INTERNSHIP 2011]
OTHER THAN MY PROJECT
UREA II
 C2E Shutdown
 NH3 Line tracing
 NH3 Reservoir (D-261)
 NH3 Condensers (E-264)
 MP 262 A/B
 URACA’S Pumps(P 201’S)
 ACES Tower visit (Thermo vision)
 Prill Tower visit
OVER ALL PLANT
 GT startup @ URUT
 Packing leak in ST @ enven
 Piston repairing @ workshop
 Visited skill shop
ENGRO FERTILIZERS Page 26

27. [T-1101] [INTERNSHIP 2011]
Shut down @ urea ii (c2e)
SHUT DOWN @ UREA II (C2E)
ENGRO FERTILIZERS Page 27

28. [T-1101] [INTERNSHIP 2011]
SHUT DOWN @ UREA II (C2E)
ENGRO FERTILIZERS Page 28

29. [T-1101] [INTERNSHIP 2011]
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30. [T-1101] [INTERNSHIP 2011]
WHAT I HAVE LEARNT?????
 Technical data handling
 T/A planning
 Equipment Order & purchase for T/A
 Total maintenance procedure
 Collaboration of Operation ,Process, Maintenance ,Inspection ,I& E and Safety section
 Non-destructive techniques
 Permit protocol
 Seniority protocol
 Crisis management
 Rapid decision making
What I DID FOR ALL OF IT????
 Spent most of the time in plant premises
 Read all history files and job cards
 Visited inspection, planning ,process ,projects
 Met the technicians of FM
 Coordinated with operators & board men in CCR
 Met senior persons worked here before
ENGRO FERTILIZERS Page 30

31. [T-1101] [INTERNSHIP 2011]
THINGS IMPRESSED ME HERE @ ENGRO
 Safety and importance of life
 Line of protocol
 Team work
 Qualified staff
 Well equipped offices
 Ethics & moral values
 Well mannered workers
 Seniority honor
ENGRO FERTILIZERS Page 31