1. PERFORMANCE MONITORING OF UREA PLANT
Presenter:
Muhammad Amin
Management Associate (Chemical)
18th Batch

2. Contents OBJECTIVE INTRODUCTION PERFORMANCE MONITORING
ROLE OF PROCESS ENGINEERING
OVERVIEW OF UREA PROCESS
HP LOOP PERFORMANCE
UREA PROCESS INDICATORS
CO2 COMPRESSOR
HP PUMPS
HEAT EXCHANGERS
UREA GRANULATION
CONCLUSION

3. Objective
To give an overview of Performance Monitoring of Urea Plant which is also part of Technical Monitoring Program (TMP) as executed by Process Engineering

4. PERFORMANCE MONITORING OF UREA PLANT
Introduction
Process:
Urea Wet: Stamicarbon, Holland
Urea Dry: Hydro Agri, Belgium
Capacity:
Design: ,670 MTPD
Raw Material:
Ammonia: ,110 MTPD
Carbon Dioxide: ,480 MTPD
Urea Formaldehyde: MTPD
Storage capacity : MT
PERFORMANCE MONITORING OF UREA PLANT

5. Performance Monitoring
To collect process data of the entire plant or its components for evaluation.
Performance indicators are calculated, highlighted to make aware of equipment running with low or high efficiency.
To identify system losses that may be causing cost impact of operation away from design point.
For early detection of wear and damage that reduces unnecessary time based inspections and improves availability, operability and efficiency of equipment.
Data of deviations from normal operating parameters help to establish, diagnose and predict performance trends that dictate future line of action.
PERFORMANCE MONITORING OF UREA PLANT

6. PERFORMANCE MONITORING OF UREA PLANT
Process Engineering
Responsible to monitor the performance of operating unit and troubleshoot or diagnose process related problems.
Execute Technical Monitoring Program (TMP) and produce report.
PERFORMANCE MONITORING OF UREA PLANT

7. PERFORMANCE MONITORING OF UREA PLANT
Process Tools
Pressure measurement
Temperature measurement
Flow measurement
Softwares:
HYSYS, HTRI etc.
PERFORMANCE MONITORING OF UREA PLANT

8. Overview of Urea Process
PERFORMANCE MONITORING OF UREA PLANT

9. PERFORMANCE MONITORING OF UREA PLANT
HP Loop
OFF GASES
OFF GASES TO ABSORBER
RECYCLE CARBAMATE SOL
SCRUBBER
REACTOR
LHS EXPORT
HPCC
Delta T
Steam
HP Loop Press
Press
OFF GASES
NH3
CARBAMATE SOL
STRIPPER
N/C
34% UREA SOL
H/U
TO RECTIFYING COLUMN
CO2 Conversion
H/U
54% Urea Sol
N/C
CO2
PERFORMANCE MONITORING OF UREA PLANT

10. PERFORMANCE MONITORING OF UREA PLANT
HP Pumps
HP Ammonia Pump HP Carbamate Pump
PERFORMANCE MONITORING OF UREA PLANT

11. Turbine Steam Consumption PERFORMANCE MONITORING OF UREA PLANT
HP Pumps
Parameter (design)
NH3 Pump
Carbamate Pump
Flow
m3/h
63.2
28.3
Efficiency %
54.4
51.7
Suction Press
Kg/cm2g
16.5
3.9
Discharge Press
168.8
149.6
Inlet Temp oC 18 74
Outlet Temp 25 69
Power KW
540
309
Turbine Steam Consumption
Kg/h
11369
6432
Turbine RPM
4000
A model of pump is generated in HYSYS.
Efficiency and developed head is calculated.
Temp, Press, at suction and discharge is recorded.
Flow at suction is recorded.
Turbine efficiency and steam consumption is also calculated.
PERFORMANCE MONITORING OF UREA PLANT

12. PERFORMANCE MONITORING OF UREA PLANT
HP Ammonia Pump
PERFORMANCE MONITORING OF UREA PLANT

13. PERFORMANCE MONITORING OF UREA PLANT
HP Carbamate Pump
PERFORMANCE MONITORING OF UREA PLANT

14. CO2 Compressor A model of CO2 Compressor is generated in HYSYS.
Efficiency of each stage.
Specific steam consumption.
Power of steam turbine and train.
Temp, Press and Flows.
NORMAL CONDITIONS (7228 RPM)
Parameter I II
III IV
Polytropic Efficiency % 81 72 75 62
Inlet Temp OC 43 63
Outlet Temp
201
199
185
140
Outlet Press
Kg/cm2g 6 24 76
149
PERFORMANCE MONITORING OF UREA PLANT

15. PERFORMANCE MONITORING OF UREA PLANT
CO2 Compressor
PERFORMANCE MONITORING OF UREA PLANT

16. PERFORMANCE MONITORING OF UREA PLANT
Heat Exchangers
Heat Duty is calculated
OHTC is calculated
Delta T
Cooling water flow is calculated
PERFORMANCE MONITORING OF UREA PLANT

17. PERFORMANCE MONITORING OF UREA PLANT
Heat Exchangers
PERFORMANCE MONITORING OF UREA PLANT

18. PERFORMANCE MONITORING OF UREA PLANT
Granulation
Bed Temperature C
Vacuum
-50 mm WC
Design Pressure
mm WC
Design Temperature
150 C
Header Pressure
kg/cm2
Urea Solution Flow rate
75-76 m3/hr
Perforated hole diameter and hole angle
2mm, 450
Level in Granulator %
Urea Solution Concentration
96% Urea
PERFORMANCE MONITORING OF UREA PLANT

19. PERFORMANCE MONITORING OF UREA PLANT
Granulation
Atomization and Fluidization air flow and pressure.
Roller crushers.
Vibrating screens.
UF-85
Granulator Washing.
As per final product specification:
Product T=50oC, Mo=0.30%, Bi=<1%, FA=>0.38--<0.46%
Larger than 4.75 mm should be less than 3 %
Between 4.75 mm and 2.3 mm, 95 % granules should fall
Smaller than 2.3 mm should be less than 2.0%
PERFORMANCE MONITORING OF UREA PLANT

20. PERFORMANCE MONITORING OF UREA PLANT
Conclusion
Performance monitoring is very important for smooth and optimum plant operations.
Performance monitoring ensures our product is produced with desired specifications.
Performance monitoring ensures the timely management of equipment health.
PERFORMANCE MONITORING OF UREA PLANT

21. THANK YOU

22. END of SLIDES

23. Urea Process Indicators
CO2 Conversion
Indicates how far the Urea reaction proceeded or used to express how much Urea is formed.
Higher N/C increases CO2 conversion.
PERFORMANCE MONITORING OF UREA PLANT

24. PERFORMANCE MONITORING OF UREA PLANT
N/C Vs Conversion
PERFORMANCE MONITORING OF UREA PLANT

25. PERFORMANCE MONITORING OF UREA PLANT
REACTOR
PERFORMANCE MONITORING OF UREA PLANT

26. PERFORMANCE MONITORING OF UREA PLANT
REACTOR
PERFORMANCE MONITORING OF UREA PLANT

27. PERFORMANCE MONITORING OF UREA PLANT
REACTOR
PERFORMANCE MONITORING OF UREA PLANT

28. Urea Process Indicators
NH3/CO2 ratio
This molar ratio is measured at the reactor outlet line (Or Initial mixture).
The principle is based on linear relationship of liquid density and N/C.
This should be between and indicates the reactor efficiency and also HPCC performance.
Higher N/C increases the CO2 conversion.
PERFORMANCE MONITORING OF UREA PLANT

29. PERFORMANCE MONITORING OF UREA PLANT
N/C Advantages
Environment protection through lower NH3 emissions and a reduction of steam consumption.
Faster plant start up.
Easier and more stable production possible.
Safer than taking manual samples.
Operation of synthesis at optimum yield.
PERFORMANCE MONITORING OF UREA PLANT

30. Urea Process Indicators
H20/Urea ratio
High water content in reactor mixture is not desirable as it shifts the chemical equilibrium to the left side.
High H/U ratio decreases the urea formation in reactor or decreases the CO2 conversion.
H/U ratio gives an indication of extra water added in synthesis section, typically via carbamate recycle.
PERFORMANCE MONITORING OF UREA PLANT

31. Urea Process Indicators
Stripper Efficiency (ALFA)
It indicates the stripper performance.
Calculated at stripper downstream.
PERFORMANCE MONITORING OF UREA PLANT

32. PERFORMANCE MONITORING OF UREA PLANT
STRIPPER
PERFORMANCE MONITORING OF UREA PLANT

33. PERFORMANCE MONITORING OF UREA PLANT
STRIPPER
PERFORMANCE MONITORING OF UREA PLANT

34. PERFORMANCE MONITORING OF UREA PLANT
STRIPPER
PERFORMANCE MONITORING OF UREA PLANT

35. Urea Plant at FFBL CONSUMPTIONS PER 1000 KG OF UREA PRODUCT QUALITY
DESIGNER/ LICENSER (WET) STAMICARBON
DESIGNER/ LICENSER (DRY) HYDROAGRI
PROCESS (WET) CO2 STRIPPING
DESIGN CAPACITY MT / DAY
PRODUCTION APRIL 1999
CONSUMPTIONS PER 1000 KG OF UREA
AMMONIA KG
CARBONDIOXIDE KG
UREA FORMALDEHYDE 9 KG
ELECTRICITY 54 KWH
STEAM KG
PRODUCT QUALITY
NITROGEN 46 %
BIURET %
WATER %
FORMALDEHYDE %
FREE AMMONIA 10 ppm

36. HP CARBAMATE CONDENSATION LP CARBAMATE CONDENSATION
BFD
HP CARBAMATE CONDENSATION
AMMONIA
ATMOSPHERE
 UREA REACTOR
SCRUBBER
ABSORPTION
34 % Urea
CARBON
DIOXIDE
STRIPPER
56 % Urea
RECTIFICATION
LP CARBAMATE CONDENSATION
75 % Urea
EVAPORATION
CONDENSATION
DESORPTION
HYDROLIZATION
96 % Urea
GRANULATION
STORAGE
EFFLUENT
GASEOUS
LIQUID

37. Plant Operation at Low Load
Since control valves, are sized for a certain max & min flow basis for their smooth operation. Accordingly, if we want to keep product specs in acceptable limits, we have to keep flow rates in that ranges.
With lower than 60% plant load, the resident time of solution in synthesis will be higher than normal value and finally will result in increased biuret formation in synthesis loop.
If plant load is below 60%, few of the stripper tubes would run dry and falling film will not be there. This will result in higher skin temperature of those tubes resulting in their severe corrosion.
PERFORMANCE MONITORING OF UREA PLANT

38. If plant load is below 60%, few of the stripper tubes would run dry and falling film will not be there in those tubes. This will result in higher skin temperature of those tubes resulting in their severe corrosion.
1-Hp control valves can not work properly lower than 60% load of synthesis.
2-If the plant load is lower than 60% ,the distribution of liquid in HP stripper tubes would be lower than normal value and some of tubes may be run with very thin film and finally will result in higher skin temperature of those tubes resulting in their severe corrosion .

39. 3-with lower than 60% plant load ,the resident time of solution in synthesis will be higher than normal value and finally will result to increase the biuret formation in synthesis loop.
The flow controling system i.e. control valves are sized to remain 60-70% open max at design load i.e. 100% of name plate capacity [to have enough margin to cope with emergincies]. Accordingly if we want to avoid / minimize any hunting in control valves [keeping same residance time to avoid distrubance in urea product specifications like biuret, moisture etc.] we have to operate these controling systems at their recommended values i.e. > 30 %. So, the controling system limits the minimum load your plant can bear for keeping your product specifications at optimum / required level.

46. Urea Reactor To HP SCRUBBER From HPCC To HP Stripper CO2 32.4 %
BIURET 0.1 %
CO %
NH %
H2O %
kg/hr oC
From HPCC
22673 kg/hr oC
To HP SCRUBBER
CO %
NH %
H2O %
N %
O %
To HP Stripper
CO %
NH %
H2O %
N %
Kg/hr 187 ºC
CO %
NH %
H2O %
N %

47. HP Scrubber To Absorber from Carbamate pump From Urea Reactor To HPCC
35529 kg/hr 70 ºC
1811 kg/hr 114 ºC
CO %
NH %
H2O %
CO %
NH %
N %
O %
H2O %
CO %
NH %
N %
O %
H2O %
To HPCC
CO %
NH %
H2O %
22673 Kg/hr 183 ºC
From Urea Reactor

48. HPCC From HP Scrubber From HP Stripper To Urea Reactor
Kg/hr 187 ºC
To Urea Reactor
95303 Kg/hr 106 ºC
From HP Scrubber
CO %
NH %
H2O %
From HP Stripper
CO %
NH %
H2O %
N %
CO %
NH %
H2O %
N %

49. PERFORMANCE MONITORING OF UREA PLANT
Granulation
PERFORMANCE MONITORING OF UREA PLANT

50. Stripper To HPCC From Urea Reactor To Rectifying Column
170oC
140oC
From CO2 Compressor
UREA %
BIURET 0.1 %
CO %
NH %
H2O %
CO %
NH %
H2O %
N %
kg/hr oC
Urea
55.4 %
Biuret
0.3
CO2
10.2
NH3
7.9
H2O
26.2
CO2
94.5 %
H2O
0.9 N2
4.0 O2
0.6

51. PERFORMANCE MONITORING OF UREA PLANT
Urea Reactor
Design Pressure 162Kg/cm2
Design Temperature 190oC
Volume 204 m3
No. of sieve trays 10
PERFORMANCE MONITORING OF UREA PLANT

52. PERFORMANCE MONITORING OF UREA PLANT
HP Stripper
Design Pressure (shell) 30 Kg/cm2 Design Pressure (Tube) Kg/cm2 Design Temperature 235oC Shell 225oCTubes No of tubes 2400
PERFORMANCE MONITORING OF UREA PLANT

53. PERFORMANCE MONITORING OF UREA PLANT
HPCC
Design Pressure (shell) 8.2 Kg/cm2 Design Pressure (Tube) 162 Kg/cm2 Design Temperature 175oC (Shell) 192oC(Tubes) No of tubes 2544
PERFORMANCE MONITORING OF UREA PLANT

54. Heat Exchangers UH-125 UH-131 UH-133 UH-134 UH-225 UH-251 UH-275