Dias nummer 1 - Danish Water Forum

danishwaterforum.dk

Dias nummer 1 - Danish Water Forum

Hvor står afsaltning energimæssigt?

Chefingeniør Christian Stamer

Krüger A/S

DWF temamøde

Vand og energi-effektivisering

torsdag den 28. april

1 -


Energi til afsaltning omfatter i bredere forstand både anlæg og

drift. Vi behøver en fælles standard for at kunne sammenfatte

det totale energikoncept.

I Veolia har vi valgt at benytte begrebet Carbon Footprint, som

udtrykker den ækvivalente mængde CO2, som aktiviteten

belaster kloden med set over en lang årrække.

Veolia har udviklet et særligt værktøj til dette formål, som jeg

vil anvende i det følgende.

2 -


Which tools to calculate

the Carbon Footprint?

Computes the GHG emissions based on basic process models

Excel spreadsheet dedicated to Carbon Footprint

Other impact indicators

Human Health (human toxicity, respiratory effect…)

Biodiversity (aquatic and terrestrial ecotoxicity…)

Resource depletion (e.g. « water footprint » under development)

Carbon Footprint =

Perimeter (construction, operation, decommissioning)

n


i1

Ai * EFi

Emissions Factor (in kg.CO2eq per)

Activity Data (tons of steel, KWh elec…)

Conversion factor: Global Warming

Potential (GWP) over 100 years

Gas

GWP over 100 years

(CO 2 eq)

Carbon dioxide (CO 2 ) 1

Methane (CH 4 ) 25

Nitrous oxide (N 2 O) 298

Hydrofluorocarbons 12 to 12,000

Perfluorocarbons 5,700 to 11,900

Chlorofluorocarbons 4,600 to 14,000

3 -

One single unit, ton CO 2 eq,

reflecting the impacts of all GHG


How to assess the Carbon Footprint ?

Life Cycle Inventory

INPUT FLOWS

Fossil fuels

Minerals

Background processes

Production

of chemicals

Production

of concrete

Production

of electricity

Ecoinvent database

For Emission Factor

Plant perimeter

OUTPUT FLOWS

Indirect GHG

Emissions

Construction

Raw water

Inventory of

intermediates

Technical modeling

of process units

Operation

Intake pumping

Water treatment

Water distribution

Decommissioning

Potable water

Direct GHG

emissions

LCA scope

4 -


Emission Factors

Construction

Concrete: 260 kg.eq CO 2 / m 3

Steel: 2770 kg.eq CO 2 / t

Power – impact of local energy mix

Operation

•FeCl 3 40%: 719 kg.eq CO 2 / t

•Ca(OH) 2 : 750 kg.eq CO 2 / t

•NaOCl 15%: 813 kg.eq CO 2 / t

•Polymer: 1.57 kg.eq CO 2 /kg

France: 0.09 kgCO 2 /kWh

Spain: 0.35 kgCO 2 /kWh

Saudi : 0.75 kgCO 2 /kWh

Australia: 0.92 kgCO 2 /kWh

5 -


SWRO desalination plant

Green House Gases emissions

in kg CO 2 -eq/m 3 of potable water

3

2,5

2

1,5

1

0,5

0

Construction < 2% of GHG emissions

Membrane renewal

Plant and piping network construction

Disinfectant NaOCl production

Remineralization chemicals production

CIP chemicals production

Antiscalant production

Coagulant / Flocculent production

Electricity production for water treatment

Electricity production for intake and distribution

RO pumping needs > 75% of GHG emissions

6 -


Impact of local energy mix

GHG emissions in kg CO 2 -eq/m 3 of potable water

4,5

4

3,5

3

2,5

2

1,5

1

0,5

0

Australian

model

Power supply

UAE grid mix

Saudi Arabia grid mix

Australian grid mix

Spanish grid mix

Nuclear thermal plant

Wind turbine

Photovoltaic cells

Combined cycle gas turbine

Oil fired plant

Coal thermal plant

UAE Saudi grid Australian Spanish Arabia mix: 99% grid mix: grid gas 75% mix: turbines, 47% coal, 22% gas coal, 20% 1% turbines, gas, oil 30% fired 5% gas 53% plants hydro/wind turbines, oil fired plants

20% nuclear electricity, 18% hydro / wind

But, energy mix is not within the scope of the suppliers of water

technology

7 -

Need to look at the C footprint of the water treatment schemes


kg CO2 eq/ m3 potable water

4

Greenhouse Gaseous emissions in kg CO2 eq/m3

for desalination plants

3,5

3

Membrane renewal

2,5

Plant and piping network construction

2

3.92 kWh/m3

average per year

3.78 kWh/m3 @

39 g/L TDS 28°C

3.84 kWh/m3

average per year

Sodium hypochlorite / sodium bisulfite

production

Sulfuric acid, sodium hydroxide, CO2

production

1,5

1

Energy mix:

98% gas

2% oil

Energy mix:

82% gas

18% oil

Energy mix:

79% coal

12.14% gas

6.36% hydro

Antiscalant and cleaning chemicals

production

Coagulant and polymer production

Electricity production

0,5

0

FUJAIRAH OMAN SUR SYDNEY

Projects

Results from Eolia TM

February 2009

François Vince

8 -


Pressure

Case Study: Oman

Salinity/ temperature impact on 1st pass RO pressure

Pressure 1 st Pass

80,0

TDS g/l

75,0

38

70,0

65,0

60,0

max 64,5 bars

Gap: 6,5 bars

39

40

41

42

45

50

55,0

min 58 bars

55

50,0

15 20 25 30 35 40 45

9 -

28

Temperature

32


Case Study: Oman

Where is the electricity consumption the highest: 1st pass

Intake

Booster

HP pump

Seawater

Pretreatment

Reverse

osmosis

Permeate

Post

treatment

Drinking

Water

Variable

frequency drive

ERD

Concentrate

Variable Frequency Drive on RO booster pumps allows

flexibility to adapt to pressure variations

10 -


kwh/m3

Kg CO2 eq/ m3

Case Study: Oman

Electrical consumption Breakdown on RO 1st pass

2,50

Emission factor at Oman: 0.92 kg CO2eq/ kwh

2.3

2,00

1.84

1,50

DWEER =

1.38

1,00

Dual Work Exchanger Energy Recovery

0.92

0,50

0.46

0,00

1 -HP RO Booster pumps 2 -DWEER Booster pumps 4-1st PASS HP pumps 5-Recirculation pump for DWEER

HP RO Booster DWEER Booster HP Pump DWEER Recirculation

type of pump

0

11 -


Case Study: Oman

Where is the electricity consumption the highest?

Example at Oman Sur : up to 76.5% of electrical consumption on the

first pass

Electrical consumption Breakdown on Oman Sur

Pretreatment 5%

1 -HP RO Booster pumps

2 -DWEER Booster pumps

4-1st PASS HP pumps

5-Recirculation pump for DWEER

6-Second pass RO pumps

1st pass RO 67-76,5%

7-Intake pumps

10-Existing plant

11-Others

12 -


Impact of the choice of membrane on electrical consumption

HYDRANAUTICS

DOW

1st PASS

Pressure at maxi conditions - worst case

(TDS max / T°C min - 4,5 years) 60,0 62,5

Boron in permeate 1st pass - worst case

(4,5years - 35°C) 3,23 2,01

2nd PASS

Pressure at maxi conditions

(TDS max / T°C min - 4,5 years) 12,0 10,2

Feed pH max 10,4 10,2

Boron in permeate 2nd pass - worst case

(4,5years - 35°C) 0,37 0,39

13 -


kWh/m3 - kgCOeq/m3

Impact of Energy Recovery Device

Pelton Turbine: 80% DWEER - ERI: 95%

3,5

3

2,5

DWEER - ERI - 95%

Pelton - 80%

2

1,5

1

0,5

14 -

0

Power Consumption (kWh/m3)

Carbon Footprint (kCO2eq/m3)


CONCLUSIONS

Tools available:

Compare water supply scenarios and main process trains

Excel spreadsheet to get into more details in the calculation

Carbon footprint of SWRO plants: 80-90% from energy

consumption

How can we reduce the Carbon footprint

Use the most efficient ERD – optimal pump

Find new membrane system configurations

Use the most energy-efficient membranes => e.g. NanoH2O

Desalination systems powered by renewable energies

15 -

More magazines by this user
Similar magazines