evolution of thermal desalination processes

8/11/2019 Evolution of Thermal Desalination Processes

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Saline Water Conversion CorporationSaline Water Desalination Research Institute (SWDRI)

Evolution of Thermal Desalination

Processes

Dr. OSMAN AHMED HAMED


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OUTLINE

Background

Evolution of MSF desalination plantsEvolution of MED desalination plants

Dual purpose power/water and hybriddesalination plants

R&D Prospects


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Evolution of Installed membrane and thermalcapacity (cumulative ) 1980-2012

Thermal33%

Membrane 67%

0

10

20

30

40

50

60

70

80

1980 1985 1990 1995 2000 2005 2008 2010 2012

membrane

thermal

year

m i l i o n m 3

/ d

0

10

20

30

40

50

60

70

80

1980 1984 1988 1992 1996 2000 2004 2008 2012


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Breakdown of Total Worldwide Installedcapacity by technology

Other (2%) Hybrid (1 %)

ED (3 %)

MED (8 %)

MSF (23%RO (63%)

74.8 million m 3 /d


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MULTI EFFECTDISTILLATION(MED)

COMMONSEAWATERTHERMAL

DESALINATIONPROCESSES

MULTI STAGEFLASH (MSF)

DISTILLATION

Evolution of Thermal DesalinationProcesses


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The multi-stage flash

(MSF) desalination process


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High reliability

& availability.Life-time over 30years

Evolutionary

Developmentsof MSF Plants

Evolutionary


Evolutionary


Evolutionary


Evolutionary



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Life TimeCapacity(migd)

YearPlantsS.#

344x51979Jeddah-III1

3210 x 51981Jeddah-IV2316 x 6.21982Al-Jubail-I33110 x 61982Al-Khobar-II43040 x 5.381983Al-Jubail-II5272 x 2.61986Al-Khafji-II62410 x 5.061989Shoaiba-I7244 x 6.51989Shuqaiq-I8

325 x 51981 Yanbu-I9

144 x 7.941999 Yanbu-II10128 x 7.52001Al-Khobar-III111110 x 102002Shoaiba-II12


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90%

7% 3%

Availability

Planned ShutdownForced Shutdown

91%

9%

Water ProductionDesign Deficiency

88%

12%

Power ProductionDesign Deficiency

Average Availability for Al-Jubail Plant Phase II(1983-2012)

Average Water and Power Load Factors for Al-Jubail Plant Phase II (1983-2012)


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12

Reasons For high reliabilityand availability

Selection ofHigh Design

Fouling Factor


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13

BHDesignFoulingFactors

Al-Khobar III 0.264 m 2 oC/kW

Al-Khobar II 0.160 m 2 oC/kW (1982)

Shuaiba II 0.211 m 2 oC/kW

Shuaiba I 0.30 m 2 oC//kW (1982)

Tawaleh B 0.15 m 2 oC/kW

Jebel Ali 0.12 m 2 oC/kW

Al-Jubail II 0.176 m 2 oC/kW (1983)


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14



Fouling Factor

Effectivealkaline scale

control


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16

3

4.5

6.5

9

15

0

2

4

6

8

10

12

14

16

85 90 95 100 105 110 115 120

A n t i s c a l a n t D o s e R a t e ( p p m )

Top Brine Temperature (oC)

Dose Rate recommended in 1981

Optimization Tests

Improvement ofChemical

Formulation

Adoption of On-Line Sponge BallCleaning System

1.5

1 .75

3.53

2.5

0

2

4

6

8

10

12

14

16

85 90 95 100 105 110 115 120

Dose Rate Optimized in 1987

SWCCs ACHIEVEMENTS IN CONTROLLING

ALKALINE SCALE FORMATION


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17

0.8 1

2.521.5

0

2

4

6

8

10

12

14

16

85 90 95 100 105 110 115 120


3

4. 5

6.5

9

15

0

2

4

6

8

10

12

14

16

85 90 95 100 105 110 115 120

A n t i s c a l a n t D o s e R a t e ( p p m )

Top Brine Temperature (oC)

Dose Rate recommended in 1981

Optimization Tests

Improvement ofChemical

Formulation

Adoption of On-Line Sponge BallCleaning System

1.5

1 .75

3.53

2.5

0

2

4

6

8

10

12

14

16

85 90 95 100 105 110 115 120


SWCCs ACHIEVEMENTS IN CONTROLLING

ALKALINE SCALE FORMATION

2010


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Economic Impact of Antiscalant Dose RateReduction in SWCC MSF Plants

7.86

4.65

3.21

0 1 2 3 4 5 6 7 8 9

Antiscalant Annual Operating cost as

per 1987 dose rate

Antiscalant Annual Operating cost as per current dose

rate

Annual Savings

M i l l i o n U S $


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Fouling Factor

Effectivealkaline scale

control

GoodSelection ofMaterial of

Construction


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20

Section Material of Construction

Brine Heater

Shell Carbon steel (all plants)

Tubes Either 70/30 o,90/10 Cu-Ni or modified 66/30/2/2Cu/Ni/Fe/Mn except Al-Jubail I (Titanium)

Heat RecoverySection

FlashChamber

First high temperature stages Al-Jubail, Al-Khafji andthe first two modules of Jeddah IV cladded withstainless steel

Al-Khobar II completely cladded with 90/10 Cu/Ni Al-Shuqaiq 1completely claded with stainless steel

Tubes All plants except Yanbu and Al-Jubail I: 90/10 Cu Ni

Jubail I: TitanuimYanbu 70/30 (1 to 10 stages)90/10 (11 to 21 stages)

Heat Rejection Tubes All plants except Jeddah & Shoaiba : TitaniumJeddah II, III, IV 90/10 Cu/NiShoaiba 70/30 Cu Ni


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21

Flash chamber of both recovery

and heat rejection sections

Carbon steel lined with stainless steel(floor lined with 317L, walls with316L and roof with either 316L or

304.

Water boxes Carbon steel lined with 90/10Copper-Nickel

TubesBrine heater tubes modified 66/30/2/2

Cu/Ni/Fe/Mn ; heat recovery tubes:

Copper/Nickel (first four stages 70/30and remaining stages 90/10)

Heat rejection tubes Titanium &modified 66/30/2/2 Cu/Ni/Fe/Mn

Projects which were recently built use the following materials ofconstruction for the major components


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Increase in distillersize

High reliability


Evolutionary


Evolutionary


Evolutionary


Evolutionary


Evolutionary



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Historical Growth of MSF Distiller Size

2.5

5.1

7.9

10

17.5

20

0

5

10

15

20

25

1973-1978 JeddahI&II kKhobar I

1979-1988 Jeddah III&IV Yanbu I Jubail

I&II Khobar II

Shuaiba I

1999-2001 Yanbu IIkhobar II

2002 Shuaiba II 2003 UAE 2011 Ras Alkhair

Low investment cost for auxiliary equipment such as interconnection and controlpiping .

Operating and maintenance people depends on the number of unit installed. Savings in operational cost.

Large unit size:

23


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Reasons Constant Reduction of Investment per MIGD optimized use of material of construction. Reduction of redundant equipment. Optimized mechanical design of evaporator vessel. Optimized thermo-dynamic design parameters.

8

6 54

12

0

2

4

6

8

10

12

14

1985 1990 1995 2000 2004

year

$ / I G D

Price Trend for turn-key complete MSF plants

2010


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Use of thermallyefficient powergeneration cycles

Evolutionary


Evolutionary


Evolutionary


Evolutionary

Developmentsof MSF Plants Increase in distillersize

High reliability


Evolutionary



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2828

After 1983 SWCC employed back-pressure turbine arrangement

Condensate Pump

MSF Distillers

Deaerator

Heater # 2 Heater # 1

G

Boiler

Fuel

Back PressureTurbine

Ejector MoistureSeparator

Power to water ratio 5 to 7.9 MW/MIGD


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After 1983 SWCC employed back-pressure turbine arrangement


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2012 Combined Gas-vapor power generation cycles coupled with MSF/RO desalinationplants

Compressor GasTurbine

CombustionChamber

SteamTurbine

Exhaustgases

Air in

RecoverySection

GAS CYCLE

STEAM CYCLE

Waste Heat Boiler

RejectionSection

Product Water

Blow downBrineHeater

Fuel in

Recycle Brine

Power Output

Power Output

Seawater in

CoolingSeawater

Reject

SWRO

1100 oC

613 oC539 oC

140 oC, 2.89 Bar EjectorSteam

18 bar, 50MW

230 oC

300,000m 3 /d 1,000,000 m 3 /d

62.5 MW

700,000m 3 /d

81MWCommonEquipment

Net 2400 MW

5 x 129.7 MW


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Financial Benefits for Dual Purpose Plants

Tremendous saving in fuel consumption related tothe desalting process

Elimination of some equipment(power plant condenser)

Dual purpose power/water plants have an overallfinancial gain against two single purpose plants.

Sharing of some common equipment (boiler and its

associated facilities, intake and outfall facilities).


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243 MW

204 MW

100Electrical

Water Production15 MIGD

DualPurpose

DualPurpose

=447 MWMW

Fuelrequirements

285 MW

280 MW

SinglePurpose

SinglePurpose

=565 MW

Fuelrequirements

Thermal Benefits of Cogeneration Plants


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ThermalProcesses

MSF

MED/TVC

MED TVC


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MED_TVCoffers the best potential method of improving the performance of straight MED desalination plants and

achieving high performance ratios and hence low water cost.

or SteamTransformer

GOR=61kg


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They provide higher overall heat transfer coefficients whencompared to multistage flash (MSF) desalination systems.

MED does not employ recycling and are thus based on theonce through principle and have low requirements for

pumping energy.The power consumption of MED/TVC plants is only around1.5 kWh/m 3 as there are no requirements to re-circulate largequantities of brine.

Increase of MED unit capacity results in the decrease of theinvestment cost.

Multi-effect distillation also offers the possibility of reducingthe plant size and footprint

Factors responsible for the recent market emergence ofMED-TVC desalination plants

EVOLUTION OF MED/TVC DESALINATION PLANTS


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0

3

69

1215

1990 2000 2009year

u n i t c a p a c i t y

M I G D

MED UNIT CAPACITY GROWTH

5MIGD

8-10 MIGD

EVOLUTION OF MED/TVC DESALINATION PLANTS

1MIGD

15MIGD

2012


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1 2 3 4 5 6 7

B

A

B

A

B

A

B

A

B

A

A A

C C

B B

Steam

ProducedSteam

Distillate throughguillotine

Distillate throughSaw line

Distillate throughU pipe

Brine suction

Cell 1 / distillatesuction

REB 5REB 3

8


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HYBRID CONCEPTS


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Integrated Hybrid systemsthe plant is designed fromthe beginning

as a combined plant .

HYBRIDSYSTEMS

Simple hybrid Systemsadding a standalone

RO desalinationplant to an existing MSF complex


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Power Plant

Electricity

To main grid

To RO Plant

To MSF Plant

MSF Unit

CondensateReturn

Steam to MSF

Heat

Rejection

SeawaterOut

CommonOutfallFacility

BlendedProduct

MSF Product

MSFMake-up

Brine

Blow Down

Single Pass

RO Unit

CommonIntakeFacility

MSFFeed

ROFeed

Seawater FeedRO

Product

Schematic diagram of simple hybrid configuration


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ADVANTAGES

Such arrangement allows to operate the RO unit with relativelyhigh TDS and consequently allows to lower the replacementrate of the membranes.

If the useful life of the RO membrane can be extended from 3 to5 years the annual membrane replacement cost can be reducedby nearly 40 percent . Blending the products of the thermal andSWRO allows for the use of a single stage SWRO instead of thetwo stage SWRO plant normally employed in standalone SWROplants.

Combining thermal and membranes desalination plant in thesame site will allow to use common intake and outfall facilitieswith less capital cost.

An integrated pretreatment and post-treatment operation canreduce cost and chemicals.


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Hybridsystems

Simple hybrid

IntegratedHybrid


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Schematic diagram of fully integrated hybrid configuration

Power Plant

Electricity

To main grid

To RO Plant

To MSF Plant

MSF Unit

CondensateReturn

Steam to MSF

Heat

Rejection

SeawaterOut Common

OutfallFacility

BlendedProduct

MSF Product

MSFMake-up

Brine

Blow Down

Single Pass

RO Unit

CommonIntakeFacility

MSFFeed

ROFeed

Seawater Feed RO

Product

Common PostTreatment

Facility


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Commercially AvailableHybrid Desalination

Plants

JeddahMSF/SWRO

YanbuMSF / SWRO

Al-Jubail

MSF/SWRO

Ras Al KhairMSF/SWRO

Product blended with MSF Product

SWRO 28.16 MIGD

Phase II MSF 40 MIGD

20 MIGD

Comman intake/outful with MSF

Product blended with MSF

1989 , Phase ISingle stage , 12.5 MIGD

1994 , Phase II

Single stage , 12-5 MIGD


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HHGas

turbine

system

HRSG

Steamturbine

MSFplant

SWROplant

Natural gas

P=10*199.7 MW

P=5*129.7 MW

P= 10*199.7 MW Pnet2400 MW

P MSF

P RO

300000m3/d

700000m3/d

1000000m3/d

P RO

Fluegases

SteamSteam

Condensatereturn

Block diagram of the combined power cycle integratedwith the hybrid MSF/SWRO desalination plant

P aux


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R&DPROSPECTS IN

THERMAL DESALINATION

Address the shortcomingsOf currently employed thermal

desalination processes

Development of desalination conceptsThat have not been fully explored and

Applied in commercial scale

Development of new desalination concepts


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R&DPROSPECTS IN


Address the shortcomingsOf currently employed thermal

desalination processes


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NF Reject

SeawaterNF Unit

NF Product

Ca = 481

Mg = 1507

TH = 7406HCO3 = 145

SO4 = 3257

TDS =45400

Ca = 72

Mg = 63

TH = 440HCO3 = 51

SO4 = 23

TDS =32060

NF/RO/MSF or NF/RO/MED Tri -hybird System

RO Reject

SWRO UnitRO Product

Ca = 281

Mg = 437

TH = 2502

HCO3 = 101

SO4 = 124

TDS = 61080

Ca = 1

Mg = 2

TH = 9HCO3 = 4

SO4 = -

TDS = 660

MSF/MED UnitMSF/MED Product


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CONCEPTUAL DESIGN OF THE HIGHTEMPERATURE AND UNIT CAPACITYMED-TVC DESALINATION PLANT


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S h i fl di f MED


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Schematic flow diagram of MEDunit of Tri-Hybrid Desalination Plant

The impact of energy cost in $/bbl oil equivalent on the water production cost


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0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60 70 80 90 100

W a t e r C o s t ( S R

/ m 3 )

($/bbl)

Standalone MED

0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60 70 80 90 100


/ m 3 )

($/bbl)

Standalone MED

MED+Power Plant

0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60 70 80 90 100


/ m 3 )

($/bbl)

Standalone MED

MED+Power Plant

StandaloneNF/RO/MED(70-30)

0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60 70 80 90 100


/ m 3 )

($/bbl)

Standalone MED

MED+Power Plant

StandaloneNF/RO/MED(70-30)

NF/RO/MED (70-30)+Power Plant


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Schematic flow diagram of trihybrid NF/RO/MSF desalination system

RO Unit

RO ProductBlendedProduct

MED/TVC Unit

MED Product

Steam

Cooling Seawater out

Cooling Seawater in

CondensateReturn

RO Reject

NF Unit

NF Reject

Seawater Intake

NF Product

Pretreatment

Make-up Seawater

MED Brine

RO Unit

RO ProductBlendedProduct

MED/TVC Unit

MED Product

Steam

Cooling Seawater out

Cooling Seawater in

CondensateReturn

RO Reject

NF Unit

NF Reject

Seawater Intake

NF Product

Pretreatment

Make-up Seawater

MED Brine

MSF

MSF

The impact of TBT on water production and energy consumption


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The impact of TBT on water production and energy consumption


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Comparison between the standalone MSF and

MSF combined with NF/RO configuration

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Standalone MSF MSF Wthin Trihybrid Scheme

Ad*102( m2 /kg/hr )

34%

Pumping Power (kWh/m3) 10% 42 %

Mc/Md23 %

Mr/Md17 %PR

39 %

68

Saline Water Conversion Corporation (SWCC)


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Prospects of reduction of operational cost

of SWCC small scale thermal desalinationplants using solar energy

Saline Water Conversion Corporation (SWCC)

Synergy between desalination and solar energy


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Electricity

RO ED MVC

RO = Reverse OsmosisED = Electrodialysis (ED)MVC = Mechanical vapor compressionTVC = Thermal Vapor compressionMED = Multieffect distillationMSF = Multistage flash distillation

TVC MED MSFRO ED MVC

Heat

TVC MED MSF

HeatElectricityThermal power

cycle

Thermalenergy

Electricity togrid

Synergy between desalination and solar energySolar desalination combinations

Concentrating solarcollector field,

Photovoltaic cells(PV)

Solar energy drivendesalination processes

solar ponds,evacuated tube , flat

plate,parabolic trough

SWCC-SWDRI/HITACHI ZOSEN Joint Solar Research Project


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j

Schematic diagram of the solar assisted thermal desalinationexperimental set-up

l


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SWDRISWCC

Solar En ergy for

Desal inat ion Plants


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R&DPROSPECTS IN


Address the shortcomingsOf current thermal desalination processes

Development of desalination conceptsThat have not been fully explored and

Applied in commercial scale


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R&D PROSPECTS

Development ofdesalination conceptsThat have not beenfully explored and

Applied in commercialscale

Membrane distillation

Freezing processes


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W a t e r

P r o

d u c t i o n

C o s

t

Year

Step Change

Evolutionary change


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Thank You

77


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evolution of thermal desalination processes

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