DESALINATION and
SAN DIEGO’S ROLE IN ITS DEVELOPMENT
SHERMAN MAY, PE 1
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INTRODUCTION
Why Desalination ? Desalination Process Development Desalination Processes Review Seawater Desalination Concerns San Diego’s Contributions Applications Summary
WHY DESALINATION ?
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EXISTING SUPPLIES •MET WATER (MWD) •GROUND WATER •SURFACE WATER
NEW SUPPLIES •BRACKISH WATER •RECYCLE •SEAWATER
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INTRODUCTION TO WATER
WATER-Essential and a Universal Solvent TOTAL DISSOLVED SOLIDS (tds)
What’s in the water
WATER SOURCE CHARACTERISTICS Brackish Sea Water
WATER QUALITY REQUIREMENTS Drinking/Industrial/Agricultural/Aquatic
COST/VALUE
TERMINOLOGY and UNITS TDS (ppm) RECOVERY RATIO (%) PRODUCT/PERMEATE BRINE/REJECT MWD (Metropolitan Water District) UNITS
Gallons (100 gallons/day/person) Cubic Meters (264 gallons) Acre Feet (326,000 gallons)
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DESALINATION PROCESS DEVELOPMENT
PRESIDENT KENNEDY-“No water resources program is of greater long-range importance than our efforts to convert water from the world’s greatest and cheapest natural resources – our oceans – into water fit for our homes and industry. Such a break-through would end bitter struggles between neighbors, states and nations” (1961)
OFFICE OF SALINE WATER Five Test Centers-One was in San Diego
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DESALINATION PROCESSES
MULTI-STAGE FLASH (MSF) MULTI-EFFECT DISTILLATION (MED) VAPOR COMPRESSION (VC) FREEZING ELECTRODIALYSIS (ED) REVERSE OSMOSIS (RO) DEVELOPING PROCESSES!
MULTI-STAGE FLASH (MSF)
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GOR-Gained Output Ratio
DESALINATION PLANT (SUPPLIES RIYADH)
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MULTI-EFFECT (ME)
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ME PLANTS
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MECHANICAL VAPOR COMPRESSION (MVC)
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MVC KESTERSON RESERVOIR
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FREEZING PROCESS
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ELECTRODIALYSIS (ED)
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RO FUNDAMENTALS
Osmotic Pressure Seawater has a TDS of 35,000 ppm and osmotic pressure of 350 psi Brackish Water is only a few thousand TDS so low
osmotic pressure (i.e. 20 psi) 16
RO MEMBRANE DEVELOPMENT
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Loeb-Sourirajan Membrane UCLA
RO MODULE
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RO SCHEMATIC
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RECOVERY RATIO (RR)
RO PLANT
PUMP BAY RO MODULES
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PROCESS COMPARISON S/W ENERGY REQUIREMENTS
SEAWATER DESALINATION PROCESS
MULTI-STAGE FLASH
MULTI-EFFECT
DISTILLATION
MECHANICAL VAPOR
COMPRESSION
REVERSE OSMOSIS
MSF MED MVC ROElectric Energy (kWhr/m3) 4-6 1.5-2.5 7-12 3-5.5Thermal Energy (kWhr/m3) 50-110 60-110 none noneElectic Equivalent of Thermal Energy (kWhr/m3)
9.5-19.5 5-8.5
none noneTotal Equivalent Electrical Energy (kWhr/m3)
13.5-25.5 6.5-11 7-12 3-5.5
(kWhr/kgal) 51-97 25-42 27-45 11-21
DESALINATION COMPARISON BRACKISH vs. SEAWATER
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% of FEED REMAINING (RECOVERY RATIO)
100 40 50 60 80 90 95 98
CONCENTRATION FACTOR 1.67 2 2.5 5 10 20 50SEAWATERTDS 35000 58,333 70,000 87,500 175,000OSMOTIC PR 350 583 700 875 1,750
BRACKISH WATERTDS 2000 3,333 4,000 5,000 10,000 20,000 40,000 100,000OSMOTIC PR 20 33 40 50 100 200 400 1,000
SEAWATER DESALINATION CONCERNS
WATER COST ELECTRICAL ENERGY USAGE ALTERNATIVES SUPPLIES
(CONSERVATION) IMPINGEMENT/ENTRAINMENT BRINE DISPOSAL GROWTH INDUCEMENT
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DESALINATION COST
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CALIFORNIA Water Accounts For 19% of Electric Usage
MWD WATER FROM NORTHERN CALIFORNIA
10.4 kWh/kgal (2.75 kWh/m3) AFFORDABLE DESALINATION COLLABORATION (ADC)
Demonstrate Energy Consumption of 10.4 to 11.3 kW-hr/kgal (2.75-2.98 kWh/m3)
PERTH, AUSTRALIA (38 mgd)
8.7 to 13.2 kWhr/kgal (2.3 to 3.5 kWh/m3) REUSE (ORANGE COUNTY GROUNDWATER REPLENISHMENT SYSTEM)
Requires About 1/3 of That Required for Seawater Desalination (SD says 1/6) BRACKISH DESALTING
Depends But Is Less Than Seawater Desalination
ELECTRICAL ENERGY USAGE
CONSERVATION SAN DIEGO’S WATER SUPPLY
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IMPINGEMENT/ENTRAINMENT
ENTRAINMENT-occurs when marine organisms enter the desalination plant intake system and enter the treatment facilities.
MOSTLY A CONCERN WITH OPEN INTAKES
INTAKE ALTERNATIVES SUBSEA OTHER METHODS
UNDEFINED REQUIREMENTS FOR RO
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INTAKE ALTERNATIVES
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SAN DIEGO’S CONTRIBUTIONS
POINT LOMA DESALINATION PLANT CLAIR ENGLE MSF PLANT-SOUTH BAY ROGA-Reverse Osmosis General Atomics SPIRAL WOUND MEMBRANE CONCEPT SEVERAL OTHER RO COMPANIES CARLSBAD DESALINATION PLANT PROSPECTS TO SHARE DESALINATION
PLANT WITH MEXICO 29
LOCAL COMPANIES MEMBRANES
Hydranautics ROGA (Koch Membranes)
ENGINEERING SPI Malcolm Pirnie PBS&J
SUPPORT King Lee Avista Myron L Home RO units
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WORLDWIDE DESALINATION APPLICATIONS
Australia-117 mgd near Melbourne (H)
Singapore-84 mgd Tuaspring Israel-143 mgd Sarek (H)
Saudi Arabia-271 mgd Ras Azzour India-20 mgd Reliance refinery Japan-13 mgd Fukuoka UAE-500 mgd Taweelah
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USA and LOCAL EXAMPLES
South Florida-33 brackish and two seawater desalination plants, additional 7 plants under construction. Total capacity 245 mgd
California-20 brackish desalting plants, 19 located in southern California. Plant capacities range from 500,000 to 10 mgd
Texas-44 municipal brackish water desalination facilities 72 mgd Desalination Plant at Yuma Oceanside-6.4 mgd operating since 1992 Water Factory 21 is 70 going to 100 mgd Proposed San Onofre S/W Desalination Plant (~100 mgd) Proposed SD recycle project Santa Barbara, Marin County, Santa Cruz,
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CALIFORNIA S/W FACILITIES
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S/W DESALINATION AT ROSARITO BEACH POWER PLANT
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RED SEA-DEAD SEA PROJECT
Jordan River water over allocated
Dead sea is being lost Water is in short supply
______________ Canal and pipeline carries
ocean water to Dead Sea Power and Desalted water
is produced
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SUMMARY
California is not unique in the application of seawater desalination
Water can have a value far in excess of its cost Desalination is a dependable water supply as
demonstrated in many countries in the world S/W desalination will become an increasing important
part of our water supply San Diego has played a key role in desalinating
development There continues to be process improvements (can’t
stand still)
INTAKE ALTERNATIVES
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INTAKE TYPE RELATIVE COST
RELATIVE PRETREATMENT
SPACE REQUIREMENTS
RELIABILITY
Beach Wells Low High Variable based upon
litho logy
Constructed Seabed/infiltration Gallery
High Medium Unknown
Submerged Open Intake
Medium-Low
Low High
Surface-Open Intake
Low Low High
Co-located Intake Low Low High