CHEMISTRY AURAIYA GAS POWER STATION

Optimization of water consumption: Journey towards zero water discharge

NTPC O&M CONFERENCE – IPS 2013

1 Shri K K Mundhada (AGM-OPN) 2. Vikas Pandey (Dy. Manager- Chemistry)

INCLUSION

Water consumption & source

Effective Measurement

Findings through external & internal audit,

suggestion, QC PC, customer meet

Water optimization schemes

Gains

1

Optimization of water consumption, describes a systems approach that reduce

the amount of water required by a process, whether it is individual consumption,

or for industrial production.

Finding a balance between what is needed by humans and what is

needed in the environment is an important step in the sustainability

of water resources.

WATER STRESS FEW FACTS

India will have the largest number of water-deprived persons in

the world in the next 25 years.

Case Study: Mumbai is not only intermittent but inequitable

4% of population receive water > 8 hrs/day

33% receive water > 4 hrs/day

42% receive water for just 3 hrs/day

21% receive water < 3 hrs/day

3

Third world war will be for water

Sunder Lal Bahuguna

Before 2007 Water

consumption

74 lakh cubic

meter

Water

cost Rs24

lakh

In 2012

Water

consumption

56 lakh cubic

meter

Water cost

Rs150 lakh

FUTURE WATER COST ?

WATER CONSUMPTION FOR PLANT WITHOU EVAPORATION LOSS & OTHER LOSSS

OPTIONS ANALYSIS

Canal Water

Pump 3X1500

M3/HR

FOR PLANT

MANGAL PUR DISTRIBUTORY OF ETAWAH CANAL

WATER SOURCE

AUGPS draws water from Mangalpur

distributory of Etawah canal originating

from Lower Ganga canal.

RAW Water Reservoir

7,73,000 M3

Live Water

Reservoir

2,46,500 M3

6

Narora Dam

A B C

RAW WATER RESERVOIR

LIVE WATER RESERVOIR

GRAVITY FILTER

5 X 350 M3/HR

USE 700 M3/HR

CLARIFIED

WATER STORAGE

TANK 150 M3

CLR WATER PUMP

FOR DM PLANT

3 X 50 M3

POTABLE WATER

PUMP 3 X 55 M3

COOLING

TOWER

GT 4 X 635 M3

EQUIPMENT

COOLING /

SEALING

CLR WATER

PUMP 3 X 60 M3

CANAL WATER PUMP

3 x 1500m3/hr

850 M3/HR

CLARIFIER

1500 M3/HR

CLARIFIER

1500 M3/HR

EVAPORATION LOSS

A 800 M3

B 800 M3

TO FIRE

SYSTEM

EVAPORATION LOSS

50M3/HR

BLOWDOWN

11.3 M3/HR

SOFTENING PLANT

9 X 250M3/HR

USE 750 M3/HR

20 M3/HR DURING

REGENERATION

DESLUDGE &

DRAINING

100 M3/DAY

EVAPORATION LOSS

840 M3/HR

COOLING

TOWER

ST 2X 23340 M3

BLOWDOWN

115 M3/HR

WASTE WATER PUMP

7 X 900 M3/HR EFFLUENT DRAIN (AVERAGE DAILY DISCHARGE 2800 M3)

30 M3/HR DURING

BACKWASH RINSE

5 M3/HR

2 M

3/H

R

CAPACITY 1000000 M3

DRAIN

FIRE WATER TANK

COOLING WATER

90%

DM WATER

0.6%

DRINKING

WATER PLANT

2%

DRINKING

WATER T/SHIP

4%

FIRE WATER

2% CLARIFIED

WATER (MISC)

1%

HORTICULTURE

ACTIVITY

0.4%

WATER CONSUMPTION PATERN

ROAD MAP FOR

OPTIMISATION OF WATER CONSUMPTION

•Measurement Effectiveness

•Field survey

•People participation: suggestion, QC PC, customer

meet

•Reporting

•Audits

9

MEASUREMENT OF WATER WITHDRAWL

Water

consumption for

plant & T/ship

Water

Evaporation loss

Water seepage

loss

Water

consumption for

plant & T/ship

Water withdraw monitoring at different source

Clarified

water

intake

Soft

water

intake

Domestic

potable

water

intake

Water consumption monitoring through reservoir level drop

DM

water

intake

Auxiliary

water

intake

Practical

approach

RESERVOIR EVAPORATION RATE

ESTIMATION

Calculation

of

Evaporation

Loss

The amount of evaporated water

empirical equation as:

g = Θ A (xs - x) /3600

g = amount of evaporated water (kg/s)

Θ = (25 + 19 v) = evaporation

coefficient (kg/m2h)

v = velocity of air (m/s

A = water surface area (m2)

xs = humidity ratio in saturated air at

the same temperature as the water

surface (kg H2O in kg Dry Air)

x = humidity ratio in the air (kg H2O in

kg Dry Air)

Referring Report on

Evaporation Control

in Reservoirs by

Central Water

Commission

FINAL RESERVOIR EVAPORATION RATE

ESTIMATION

summary of 03 methods tried as above:

Evaporation loss practical approach =17.33mm/day

Referring Report on Evaporation Control in Reservoirs by

Central Water Commission =12-14mm/day

Calculation for Evaporation Loss in Raw & Live

Reservoir by empirical equation as used for small reservoir

and swimming pool =12.71mm/day

Excel sheet for calculation of evaporation loss

14

SEEPAGE LOSS

Water

Evaporation loss Water drawn to

Reservoir

Water consumed

in plant & T/ship

Excel sheet for water balance

Bottom and all sides of these reservoirs consists of 25 mm sand blanket +

LDPE Film + 10 mm cement mortar + burnt tile lining to control percolation

loss .

Residents awareness

regarding water use

People participation

Clariflocculators B/D recycle

Cooling tower over flow redirected to basin

Quality Circle

Professional Circle

ST cooling blow down at

salt lagoon for salt solution preparation

DM water reduction by benchmarking

Customer meet

ST cooling blow down for fire water

GT Cooling Water B/D

Rerouting to ST Cooling water channel

Softener backwash O/L

water to Gravity Filter rinse drain pit

Recycle of DM Plant

filter back wash effluent to reservoir

Gravity Filter B/W Water Recycling to Reservoir

WATER CONSUMPTION OPTIMISATION THROUGH TOTAL INVOLVEMENT

Suggestion Scheme

Cooling tower overflow

diverted to basin

Use of SWAS Drain in

to GT cooling water

Use of stp effluent

Gravity Filter Rinse

Water Recycled to Gravity Filter I/L

Completed Water conservation scheme 1

Recycle of GT Cooling water to ST cooling tower basin

GT 1 GT 2 GT 3 GT 4

ST 1 Cooling Tower

Basin

ST 2 Cooling Tower

Basin

Over flow Blow down Blow down Over flow

Saving= 15M3 x 4 x 24 x 365

= 525600M3 / Year Chemical parameters of

effluent

COC<2.5

COC<6.0

COC<2.5

COC<6.0

18

Recycle of GT Cooling water to ST cooling tower basin

Level switch

Dewatering pump

Water recycle scheme no 2

Recycle of Gravity Filter Back Wash effluent back to reservoir

3 5 4 2 1

UNDER

PIPE

Gravity Filters at Softening Plant

Back wash effluent from Gravity Filters

To Raw Water

reservoir

Earlier system

Going to Drain

B/W inlet

Saving= 400M3 x 365

= 146000M3 / Year

Chemical parameters

of effluent

20

Recycle of Gravity Filter Back Wash effluent back to reservoir

Water recycle scheme no 2

Recycle of Rinse water back to Gravity Filter I/L

3 5 4 2 1

Rinse water from Gravity Filters to Rinse drain pit

Drain

Gravity

filter I/L

Saving= 60M3 x 365

= 21900M3 / Year

RINSE DRAIN

PUMP

Water recycle scheme no 3

Chemical parameters

of effluent

Water recycle scheme no 4 Recycle of Filter B/W to reservoir

CONSERVATION

PIT

To raw water reservoir

Exis

tin

g s

yste

m ,

To D

rain

Saving

44308 M3 / Year

Activated Carbon

Filter

(2)

DM Plant sand Filter

(2)

Potable Filter

(3)

BLOW DOWN

Chemical parameters of

effluent

Water recycle scheme no 6

Steam Turbine Cooling Blow down for fire water

ST Cooling Water

Blow down

FIRE WATER

TANK-1

(925M3)

FIRE WATER

TANK-2

(925M3)

Saving

146000 M3/Year

Chemical parameters of effluent

Pump

PARAMETERS

ST CBD

WATER

FIRE

WATER

pH 8.5-9.3 8.5-9.3

Specific Conductivity 700-1200 200-260

Turbidity (ntu) 0-5 30-60

Total-Hardness(ppm) (as CaCO3) 5-30 100-200

Chloride(ppm) (as CaCO3) 100-150 20-40

Reactive Silica (ppm) 2.0-5.0 2.0-5.0

Water recycle scheme no 7

Steam Turbine Cooling Blow down at salt lagoon

ST Cooling Water

Blow down

Well-1 Well-2

SALT LAGOON

Saving

18250 M3/Year

FOR

HORTICULTURE

USR

OH TANK

SALT LAGOON Pump

Chemical parameters

of effluent

RAIN WATER USE

RAIN WATER

HARVESTING

RAIN WATER

REROUTING

1 2 3 4

5

HARVESTING PIT

6 SOFTENING PLANT

ROOF RAIN WATER

Saving

10000

M3/Year

GF

INLET

Water recycle scheme 5

Recycle of Softener B/W water back to Gravity Filter I/L

3 4 2 1

Softener Vessel at Softening Plant

B/W water from Softener to Rinse drain pit

Exis

tin

g d

rain

RINSE DRAIN

PIT

Saving= 90M3 x 365

= 32850 M3 / Year

5 6 7 9 9 8 7 6 5 4 3 2 1

Chemical parameters

of effluent

COMPLETED SCHEMES

REDUCTION SCHEMES SAVING M3 /

YEAR

1 GT CBD WATER REROUTING TO ST COOLING WATER CHANNEL 525600

2 GRAVITY FILTER B/W WATER RECYCLING TO RESERVOIR 146000

3 GRAVITY FILTER RINSE WATER RECYCLED TO GF I/L 21900

4 RECYCLE OF DM PLANT FILTER BACK WASH EFFLUENT TO RESERVOIR 44308

5 ST COOLING BLOW DOWN FOR FIRE WATER 146000

6 ST COOLING BLOW DOWN AT SALT LAGOON FOR SALT SOLUTION PREPARATION 18250

7 WATER USE RESTRICTION BY DECREASING SUPPLY TIME 51100

8 DM WATER REDUCTION BY BENCHMARKING 7300

9 RAIN WATER REUSING IN GRAVITY FILTER I/L 10000

TOTAL 960458

WATER CONSUMPTION

YEAR

6884593 6807917

5617031

5001451

500000

1500000

2500000

3500000

4500000

5500000

6500000

7500000

2009-10 2010-11 2011-12 2012-13

WATER CONSUMPTION (CUBIC METER)

*projected consumption for 2012-13

RESERVOIR

CLARIFLOCCUL

ATOR B/D

(100 M3)

DM PLANT

REGENERATION

WASTE (30 M3)

SOFTENING

PLANT GRAVITY

FILTER B/W

(400 M3)

RINSE DRAIN

PIT WATER

(60 M3)

SOFTENER B/W

(90 M3)

SWAS SAMPLE

DRAIN

(30 M3)

WHRB B/D

WASTE

(5 M3)

DM PLANT

FILTERS B/W

(121 M3)

GT COOLING

WATER B/D

(1440 M3)

ST COOLING

WATER B/D

(2640 M3)

OTHER

CLEANING

WASTE (5 M3)

FINAL PLANT

EFFLUENT

(1890 M3)

PIT FIRE WATER

TANK

(800)

SALT

LAGOON

(200)

Fig: Daily effluent balance

SOFTENER

REGEN WASTE

(180 M3)

30

SCHEMES PROPOSED

SAVING

M3 / Yr

Reverse osmosis based CBD treatment plant 569400

RO based ETP plant

REJECT OF RO PLANT

Well-1 Well-2

SALT LAGOON

OH

TANK

FOR

HORTICULTURE

USR

SALT LAGOON

USE OF RO REJECT

FOR TOILET

FLUSHES

ST COOLING BLOWDOWN, 2640

GT COOLING BLOWDOWN, 1440 DM PLANT FILTER

B/W, 121

SOFTENING PLANT GRAVITY FILTER B/W,

400

GRAVITY FILTER RINSE DRAIN PIT, 60

SOFTENERS B/W , 90

CLARIFLOCCULATOR BLOWDOWN, 100

DM PLANT REGENERATION

WASTE, 30 TOWNSHIP STP

WASTE, 600

SWAS SAMPLE DRAIN, 30

REUSE

WATER

DM PLANT, RO

REGENERATIO

N WASTE, 430

EFFLUENT DISCHARGE AFTER IMPLEMENTATION OF

PROPOSED SCHEMES

1890 M3

/DAY

430 M3

/DAY

WATER SAVING COMPLETED PROPOSED

WATER SAVING (CUBIC METER) 960458 626850

Pumping cost canal water pump (Rs 0.02367/m3) 22734 14838

Pumping cost raw water pump (Rs 0.092/m3) 88362 57670

Pumping cost effluent water pump (Rs 0.144/m3) 138498 90392

Pumping cost filter/fire water pump (Rs 0.222/m3) 213222 139161

Chemical cost (pre treatment cost) 87571 57154

Effluent neutralization cost 2000 1500

TOTAL SAVING /YEAR (Rs) Rs 552387 Rs 360714

GRAND TOTAL (RS) Rs 913101

. . . strike a balance between conserving our limited water

resources and facilitating development

THANK YOU

Every Drop counts

Web resources

•www.usibc.com/sites/default/files/.../files/towardsanintegratedsolution.ppt

•ww.worldenergy.org/documents/11.151mex._city.ppt

•12thplan.gov.in/.../20_Key%20Challenges%20for%2012th%20Plan%20-

%20Initial%20CII%20Note.ppt

•www.kelman.com.br/ppt/DesigningEffectiveNationalIncentive.ppt

•www.sustainableplant.com/.../ge-says-better-incentives-needed-to-stimulate-water-reuse-and-

recycling/

•www.gpem.uq.edu.au/docs/.../OzWater_Brisbane%20Waterpaper.pdf

•www.civil.iitm.ac.in/.../PPT_Discussion%20with%20WSP_21st%20Aug%2009_changed.ppt

•www.karunadu.gov.in/.../Presentation%20on%20Water%20Sector%20-

%20Emerging%20Challenges.ppt

•www.ucowr.org/updates/pdf/V111_A7.pdf

•www.igidr.ac.in/~ashima/Water-iir-ashima-preprint.pdf

•www1.gadnr.org/sustain/files_ppt/wcw1-a.ppt

•Ntpcindia.com, ntpc intranet

•Water balance report

35

Metering & Accounting

Water distribution system should be water tight

Residents awareness regarding water use should be enhanced

Common place water taps should be of auto close type.

All cistern type flush tanks toilets should be converted to smart

type flushes with flushes short &long.

Retrofits for water tap to reduce water consumption

REDUCTION IN DOMESTIC CONSUMPTION

36

COMPLETED COST

1 Recycling of GT cooling water blow down pump & pipeline 150000

2 Drain pipe for gravity filter backwash to reservoir 20000

3 Rinse drain recycling pipe 10000

PROPOSED COST

1 Dm plant filter B/W water recycling pit & pump 110000

2 Softener B/W drain & piping 180000

3 Reverse osmosis based ETP 24000000

4 Pump for water to salt lagoon OH tank 40000

5 Revival of horticulture pipeline network 220000

6 Retrofits for water conservation 10000

Total 24740000

37

38

IDEA SHARING