Background
BRINE TREATMENT USING
Water pollution by industrial brines
FREEZE DESALINATION
Sources
of brine
TECHNOLOGY
(HybridICE™
Technology)
Reverse Osmosis
Electro-dialysis
T Mtombeni
J P Maree, W J Louw, J K O Asante, F Oosthuizen, C M Zvinowanda
Live your life. Create your destiny.
Page  1
Current Treatment Methods
Evaporation ponds
Distillation
Deep Well injection
Page  2
A new approach to Brine treatment
Evaporation ponds
Advantages
Drawbacks
Very low operational costs
Leaching
Free energy (solar driven)
Expensive lining material
Minimal maintenance costs
High cost of land
Slow process
Depends on climatic conditions
Susceptible to natural disasters
Page  3
A new approach to Brine treatment
Distillation
Advantages
Page  4
Drawbacks
High water recovery (99%)
Energy intensive
Zero Liquid Discharge
Costly process
Potential mineral recovery
Scaling and Corrosion
A new approach to Brine treatment
Comparison of Freeze and Evaporation methods
Parameter
Freeze
Evaporate
Temperature change dT
Energy required to reduce tempt to 0°C (MJ/m3)
Energy required to freeze/evaporate 1 m3 of water
(MJ/m3)
Energy required to freeze/evaporate 1 m3 water
(GJ/m3)
Energy required to freeze/evaporate 1 m3 water
(kWh/m3)
25.0
104.5
75.0
313.5
333
2,257.0
0.44
2.57
121.53
714.03
Price (R/kWh)
Cost to freeze/desalinate 1 m3 (R/m3)
0.30
36.46
0.30
214.21
1
6
Cost ratio
Page  5
A new approach to Brine treatment
Freeze desalination
History
Old technology but generally not accepted due to:
Process complexity
Solid-Liquid phase separation
High capital costs
Page  6
A new approach to Brine treatment
Freeze desalination
Advantages
Low energy costs
Zero Liquid Discharge
Potential mineral recovery
Low operating temperature
Minimal corrosion and scaling
Energy recovery
Low cost materials
Pre-treatment not necessary
Low ecological impact
Page  7
Drawbacks
High capital costs
Process complexity
Impurity entrapment
Freeze-up
A new approach to Brine treatment
Concentrate
The
HybridICE™
Brine
Page  8
The
HybridICE™ Technology
… a new approach to Freeze Desalination
HybridICE™ P&ID
A
A – Ice outlet (ice sampling point)
B – Concentrate outlet (feed sampling point)
C1 – Compressor
HX1 & 2 – Scrapped Surface heat exchangers
HX3 – Refrigerant condenser (forced air)
M1,M2,M3 – Electric motors
P1 – Centrifugal pump
PI-101, PI-102, PI-103, PI-104 – Pressure indicators
R-101 – Brine storage tank
U-101 – Ice filter
V-101 – Brine valve
V-102, V-103 – Evaporation temperature control valves
VFD1, VFD2 – Variable frequency drives
WI-101 – Weight indicator (Mass lost = Mass of ice)
U-101
PI
103
M3
HX2
VFD
2
C1
M2
B
HX1
VFD
1
M1
WI
PI
PI
104
V-103
101
101
PI
102
R-101
V-101
Page
9
The
HybridICE™
Technology
V-102
P1
HX3
F1
… a new approach to Freeze Desalination
HybridICE™ Filter operation
Ice out
…
…
…
Slurry in
Concentrate out
The HybridICE™ Technology
… a new approach to Freeze Desalination
Ice from the HybridICE™ plant
The
HybridICE™
Technology
Page
 11
… a new approach to Freeze Desalination
HybridICE™ Key Attributes
Production of ice without washing
Compact and simple technology
Low energy consumption and energy recovery
Free cooling energy (Case of AngloGold, Mponeng Mine)
Retrofitting of existing systems
Page  12
The
HybridICE™ Technology
… a new approach to Freeze Desalination
HybridICE™ Key Attributes
High impurity removal
No use of chemicals
Cheap materials used in plant design
Minimal scaling and corrosion
Page  13
The
HybridICE™ Technology
… a new approach to Freeze Desalination
Mine cooling using ice
Case of Anglo Gold Ashanti Mponeng mine
Depth
Virgin rock temp.
Cooling water temp.
Service water
Installed capacity
Water circulated
Electricity generation
Savings by load shifting
(ice dams)
Page  14
The
HybridICE™ Technology
:
:
:
:
:
:
:
:
3.5 km
54.5°C
3°C
10°C
4,200t/day
49ML/day (-5*)
32GWh/month
2.3%
… a new approach to Freeze Desalination
HybridICE™ Applications
Brine treatment
Heat pump
Pre-heating stage
HybridICE™
Impurity
concentration for
chemical recovery
Page  15
The
HybridICE™ Technology
Space cooling
… a new approach to Freeze Desalination
Conclusion
Evaporation pond disposal
Attractive but environmentally unfriendly
Slow process
Distillation
Energy intensive
High operational & capital costs
Page  16
The
HybridICE™ Technology
… a new approach to Freeze Desalination
Conclusion cont’d
Freeze desalination (HybridICE™ Technology)
Low energy consumption
High impurity removal
Simple and compact
Environmentally benign
Page  17
The
HybridICE™ Technology
… a new approach to Freeze Desalination
THANK YOU
Email : mtombenit@tut.ac.za
Cell : 0027788745617
The
HybridICE™
Technology
Page
 18
… a new approach to Freeze Desalination