1. Design, Modeling and Simulation of Seawater RO Desalination Plant
ENGINEERING
UAEU
Design, Modeling and Simulation
of Seawater RO Desalination Plant
Presented by
Haleimah Mohamed
Tamadher Ali Mohamed
Reem Khalifa
Fatima Al-Zarouni
Under the supervision of
Dr. Mohamed Abdulkarim

2. Anti-scalant addition Neutralization pH adjustment
Process flow Diagram
HCl
Al2(SO4)3.14.3H2O
SBS
Disinfection
pH adjustment
Anti-scalant addition
Media Filter
Coagulation unit
Cartridge
Filter
(Chlorination)
De-Chlorination unit
Neutralization pH adjustment
Storage Tank
RO Membrane
NaOCl
Hypersperse AS110
HPP
NaOH
Pump

3. Material Balance - Media Filter
Used to prevent reverse osmosis membrane from fouling by removing large percentage of suspended solid from feed water
SDI measurement commonly used to indicate the effectiveness of media filter
Almost, all RO membrane manufacture recommends SDI to be less than 3

4. Material Balance - Antiscalant
[Ksp] =
2.44 x10-5
1.05 x10-4
L/day
[Ca+2] x [SO4-2]= 4.23 x 10-4 mol/L Ksp= 2.44 x 10-5
The equation of calulating the dose rate
Antiscalant (Hypersperse AS110)

5. Material Balance - Cartridge filter Plant SDI before cartridge
SDI after cartridge
Al Jubail, Saudi Arabia RO desalination plant 3
2.8
Singapore pilot plant
6.5
6.1
desalination plant at Larnaca, Cyprus

6. Material Balance
- Cartridge filter

7. Material Balance - Dechlorination
Normally, the available free chlorine concentration before RO membrane is 0.5 – 1 ppm.
The maximum allowable chlorine concentration before RO membrane is 0.05 ppm.
Residual free chlorine can be removed by:
adsorption onto activated carbon media filter
chemical reducing agent (SBS)

8. - Dechlorination Chemical
Material Balance
- Dechlorination Chemical
Sodium Bisulfite can be formed by dissolving Sodium Metabisulfite (SMBS) in water
In theory, 1.34 mg of SMBS will remove 1 mg of free chlorine.
In practice, designers used to add 3 mg/L of SMBS of chlorine
Total amount of free chlorine in water = 503 * 106 mg /day

9. - Dechlorination Chemical
Material Balance
- Dechlorination Chemical
SMBS
H2O
SBS
The amount of SMBS needed to remove free chlorine = mole/day
The amount of moles of Sodium Bisulfite needed to remove the free chlorine = 15, mole/day
The dosage rate of SBS needed to remove residual chlorine = gal/day

10. Material Balance RO membrane - RO membrane Q6 Stage 1 Stage 2 Q1 Q2 Q4

11. Material Balance - RO membrane Parameters Value Overall Recovery% 30%
Recovery for second stage
85%
Salt rejection %
95%
Total product
40MGD
Total dissolved solid for total product
170 ppm
Total dissolved solid for feed
43153ppm

12. Material Balance - RO membrane Q6 Q1 Q2 Q4 Q5 Q3 Q2 =47 MGD
TDS2 = ppm

13. Material Balance - RO membrane Q6 Q1 Q2 Q4 Q5 Q3
Material balance on second stage:
TDS5 =13415 ppm Q6 Q1 Q2 Q4 Q5 Q3
Material balance on first stage:
The overall salt balance for the system
TDS6= ppm

14. Material Balance - NaOH
Added for pH adjustment to minimize the corrosion in the product water pipes
The required pH for drinking and potable water is in the range of 6.5 – 9.5
The calculation was based on
Neutralization of acid
Adjust pH from 7 to 8

15. Design - Cartridge filter Feed flow rate = 349 x 103 L/min
Capacity of each filter = 600L/min
feed water flow rate / filter capacity = Number of filter element
number of filter = 582 filter
Number of vessel = 25
( 23 in operate + 2 standby)
Filter cartridge/ vessel = 26
ΔP = 4 psi per 1 m3/min
The feed flowrate inter each vessel= 15 m3/min
Total ΔP = 15 x 4 = 60 psi = 4 bar

16. Design
- Ultrafiltration
number of module =
module

17. Design
- Ultrafiltration
number of configuration = 203 configuration

18. Design ions C (mg/l) C (mol/L) Mg+2 829.35 0.03412 Ca+2 488 0.0122 Na+
- RO membrane
ions
C (mg/l)
C (mol/L)
Mg+2
829.35
Ca+2
488
0.0122
Na+
0.572
HCO3_
115.9
0.0019
SO4-2
3473
Cl-
23811
0.6726

19. Design
- RO membrane
For feed

20. Design properties Stage #1 Stage#2 47 MGD 40 MGD 2755 L/h 2690 2290
- RO membrane
properties
Stage #1
Stage#2
Permeate flow
47 MGD
40 MGD
Qper,vessel
2755 L/h
# of vessels
2690
2290
# of element
16140
13740

21. Design
- RO membrane
Feed
Permeate
One vessels

22. Design
- RO membrane
The calculations of pressure drop in RO membrane

23. Environmental Impact Products Chemicals Sodium Hypochlorite
Antiscalent
Hydrochloric acid (HCL)
Sodium bio-sulphate
Coagulant (Aluminum sulphate)
NaOH
2. Process
MMF
Membrane
Desalination plant Intake
Products
Brine

24. Actions Advantage: Disadvantages: Sand filter Chemicals Process
Sand work as a filter
Disadvantages:
Need higher pressure
Limits on flow rate
Cost

25. Actions 3. Products Mix brine with seawater before discharge.
RO plant
Feed seawater
To seawater
Mix brine with seawater before discharge.
2) More than one discharge.
These are located a way of each other at a distance.
3) Mixing brine water with cooling water coming from adjacent power plant.
4) Evaporation ponds
5) Deep well disposal

26. HAZOP Analysis
PID Before HAZOP

27. HAZOP Analysis
HAZOP analysis on water feed entering multi media filter. (Line no. 2)
Guide Word
Deviation
Causes
Consequences & Action NO
FLOW
Pump failure
Ruptured (broken) pipe
Valve (V2) shut
No product
Check valve
Check & Repair pump and pipe
Put flow indicator (FI 2)
LESS
Pipe leakage
Low production quality
Less feed pressure
Slow operation
MORE
Damage pump
The multi media will be shutdown.
The ratio between feed water and coagulant is not the same
Need to fix coagulant dosing
The efficiency of media filter will decrease.
The suspended solid will not be removed
Lower the product quality
Over flow
Lower removal capacity
Check & Repair V2

28. PID After Hazop

29. Modeling and Simulation
- Reference Process

30. Any Question??