Desalination: A Global Perspective
Craig R. Bartels, PhD HYDRANAUTICS
1 Desalination Growth: Installed Capacity, 1980 – 2010 (cumulative)
Desal ng Technology Total Electric Energy Equiv. kWhr/m3 Mul ple Effect Dis lla on 5.7-6.5 Mul ple Stage Flash 17-18 Reverse Osmosis 3-5 1,800,000 8x40” Spiral Elements Typical Life: 3-6 years
2 DESALINATION TECHNOLOGY
3 RO Membrane Separation Mechanism
Pressure
++ + SO Fe FEED Na 4 ++ H2O Mg Concentrated FLOW Salts ++ HCO3 Ca H2O Cl H2O H2O
H O H O 2 H O 2 2 Membrane
H O H2O 2 H2O
Permeate
4 Osmotic Pressure
Semi Permeable Membrane P
π1 π2
P = π2 - π1 = Δπ
Applied pressure required to prevent the flow of water through a semi- permeable membrane from a dilute solution to a concentrated solution. Osm Press ~ 0.011* salinity in mg/l Reverse Osmosis
Semi Permeable Membrane P
π1 π2
P > (π2 - π1)
Osmotic flow can be reversed by applying a pressure greater than the osmotic pressure difference between the two solutions
6 SWRO Pressure Requirement Recent Membrane Improvements
62 bar = 900 psi
Bar 20 16 14 33% of pressure is used to Only 25% of permeate pressure is used to water permeate water through the through the membrane membrane 7 GLOBAL COMMERCIAL APPLICATION
8 Regional Size of Desalination Market
26.4 BGD
Water Desalina on Using Renewable Energy Technology Brief Interna onal Renewable Energy Agency, IRENA ENERGY TECHNOLOGY SYSTEMS ANALYSIS PROGRAMME, March 9 2012 Large-Scale Plant References Example of Major Global Desal Plants
Seawater Desalination : Total 6,000,000 /d and over � ㎥ Japan Okinawa Wastewater Reclamation : Total 1,000,000 ㎥ /d and over 40MLD ’97
China Fukuoka Spain 50MLD ’05 Yuhuan 11.5MLD ’06 Carboneras 126MLD ’02 Yueqing 10MLD ’07 Cartagena 65MLD ’03 Qingdao 10MLD ’07 Escombreras 64MLD ’07 Singapore Tianjin 100MLD ’09 Bedok 42MLD ’02 Barcelona 200MLD ’09 Kranji 40MLD ’02 Ulu Pandan Algeria 166MLD ’06 Skikda 100MLD ’08 Beni Saf 200MLD ’08 Tlemcen 200MLD ’09 Honaine 200MLD ’09
USA Chennai India Orange County 100MLD ’09 264MLD ’06 100MLD ‘13 Oman USA Saudi Barka Israel Tampa Arabia 125MLD ’08 Sorek 95MLD ’06 Rabigh Sur 440MLDMLD: ’13 Carlsbad 192MLD 84 MLD ‘09 Million Liter Per Day 190 MLD ‘15 UAE Fujairah 170MLD ’03 Australia ’ Chile Al Hamriya 90MLD ’08 Gold Coast 132MLD 09 Antofagasta 52MLD ’03 Adelaide 300MLD ’10 Melbourne 450MLD ’10 6 Key Aspects Affecting Desalination
INTAKE CAPEX 5-15% CAPEX 5-20% OUTFALL
PRETREAT CAPEX 15-20% RO SYSTEM CAPEX 40-60%
POWER PRODUCT WATER
11 Carlsbad, CA Desal Plant Global Desal Trends/Considerations v Reliability v Seawater quality, redundancy, technology acceptance v Energy Consumption/Cost v Membranes, Co-location at Power Plant v Water Quality Targets v TDS, Chlorides, Boron, Bromide, TOC v Pretreatment v Media Filters, Ultrafiltration, Floatation (DAF), v Intake/Outfall v Permitting, Shared intake, Wells, Env impact
12 Water Cost Components of a SWRO Plant
Electric Power: 33%
Maintenance: 8%
Chemicals: 4%
Labor: 4%
Membrane Replacement: 3% Equipment Amor za on: 48%
13 Reported Energy Use in SWRO Plants
SWRO Energy SWRO Energy Facility Energy Plant Capacity m3/d Capacity MGD only $/1K gal only kWh/m3 kWh/m3 permeate ADC Pilot 1.58 290 0.08 $0.42 Melbourne 2.2 450,000 119 $0.59 Perth 2.47 4.34 144,000 38 $0.65 Barcelona 2.88 200,000 52.8 $0.76 Mekorot 3.74 10,000 2.6 $0.99 Fujairah 3.80 4.50 170,000 45 $1.01 Ashkelon 3.90 330,000 87.2 $1.03 Gold Coast 4.00 133,000 35 Valdelen sco 4.17 200,000 52.8 Las Palmas 4.35 36,000 9.5 Larnaca 4.42 52,000 13.7
14 Energy es mated at $0.07 USD per kWh Energy Efficiency: Gold Coast Plant
• Desalina on plant: $557.5 mill • Intake/ou all: $280.6 mill • Distribu on pipeline: $218.5 mill • Total capital cost: $1.057 bill • Total water cost: $1.09/m3 $4.12/kgal
35 MGD 133,000 m3/d < 250 mg/l TDS < 50 mg/l Cl < 0.1 mg/l Br < 1 mg/l B
15 Reference: GHD publication, Gary Crisp, & WDR Energy Use in the Gold Coast Plant
4.5 2.9 kWh/m3 11 kWh/kgal 4 (80% of energy) 3.5 Transformers losses 3 Chemicals dosing pumps 2.5 Misc. services 2 Residuals treatment
1.5 Potable water pumps Intake pumps 1 Pretreatment
Specific energy consumption (kWh/m3) 0.5 RO 0 < 50,000 m3/day > 100,000 m3/day
Plant production
16 133 MLD Gold Coast SWRO Energy Consumption
4.50 Total plant specific energy consumption
Pretreatment + RO specific energy consumption 4.00
3 3.50
kWh / m / kWh 3.00
2.50 Energy Reduced ~10% by “Split Permeate” Design
2.00
17 Mega Plant: Melbourne, AUS
41,200 8” SWRO Elements 14,280 8” BWRO Elements SWRO: 800 psi (8.4 kWh/kgal) < 20 mg/l Cl < 0.5 mg/l B < 0.1 mg/l Br Source: WDR, Vol 48, #40 18 15 October 2012 18 Melbourne Plant Pressure Profiles
Gold Coast SWRO Melbourne SWRO
SWC5 Avg Fd Press
19 Seawater Pretreatment Options v Beach Well v Coagulation and Clarification v Dual Media Sand Filters v Dissolved Air Flotation v Ultra/Micro Filtration
20 Growth of Membrane Pretreatment (based on 96 plants listed in public)
MF/UF Pretreatment in Seawater Desalination: Applications and Trends Authors: Robert P. Huehmer, IDA Proceedings, Dubai 2009 Kindasa IMS Plant System Layout
Start-up Fall 2006
22 Kindasa Ultra Filtration System
• Design Capacity – 14.9 mgd (56,500 m³/d) • UF Membrane – HYDRA cap60 • MWCO – 100,000 Daltons • Number of Racks – 8 • Design Flux – 53 gfd 97 lmh • Max. Flux – 61 gfd 106 lmh • Recovery – 94% • Mode – Dead End Filtration • No Coagulant Addition
* These are not actual feed pressure values, but feed to filtrate differential pressure values (driving pressure) Average Filtration Energy Consumption
UF UF DMF DMF BW Filtr’n BW Filtr’n Feed Flow (Avg) (gpm) 4,400 1,244 4,893 2,244 Feed Pressure (psi) 36.3 3.04* 14.5 4.4* Pump Efficiency (%/100) 0.84 0.86 0.78 0.81 Pump Power (kW) 83.7 1.9 39.9 5.3 Hours of oper’n (Hours/day) 1.3 24.0 0.08 24.0 Motor Efficiency (%/100) 0.85 0.94 0.94 0.94 Specific Power (kWh/kgal) 0.071 0.028 0.001 0.042 Total Specific Power (kWh/kgal) 0.099 0.044 * These are not actual feed pressure values, but feed to filtrate differential pressure values (driving pressure)
24 Average RO Energy Consumption Average RO Energy Consumption
Energy Credit from Energy Recovery Device
SWRO SWRO SWRO BWRO HPP BP ERT LPP Feed Flow (Avg) (gpm) 3,568 2,364 1,783 1,418 Feed Pressure (psi) 847 215 998 197 Pump Efficiency (%/100) 0.9 0.8 0.9 0.8 Pump Power (kW) 1540 293 920 148 Hours of oper’n (Hours/day) 24 24 24 24 Motor Efficiency (%/100) 0.85 0.94 1.00 0.95 Specific Power (kWh/kgal) 17.550 2.962 8.733 2.071 Total Specific Power (kWh/kgal) 11.779 2.0713
25 Relative Contribution of Plant Energy Consumption
0.20% 0.01% Specific Power 0.51% 0.30%
14.80% SWRO HPP-ERT SWRO BP 24.84% BWRO LPP 73.96% UF Bflush UF Filtration DMF BW DMF Filtration
26 Sorek Desalination Plant: 16 in SWRO
410,000 m3/d 108 mgd < 16 mg/l Cl < 0.26 mg/l B
Ver cal Vessels
16”: 1700 2 8” : 400 2
27 Sorek Compact Plant Design
1400 press Water Selling Price: vessels versus ~US$0.50 per m3 5950 for 8” ~US$1.89 per kgal elements
28 Conclusions v RO Desalination is most prevalent in Middle East and Mediterranean regions v RO Desalination plants are typically reaching 50-100 mgd capacity v RO Desalination growth has been fueled by lower energy costs, high reliability, and greater experience v Energy costs range from $0.60 to $1.00 per kgal v Significant growth of membrane pretreatment v Cost reduction through new concepts such as improved membranes, co-location, and large elements.
29 More technical information can be found at: www.membranes.com
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