WATER CONSERVATION & QUALITY
IMPROVEMENT INITIATIVES
H.S.BAGGA
VINOD RATAN
PRAG SOOD
From Industrial prospective, High cost, strict environmental regulations & poor availability of fresh water has emerged as one of the big challenges and driven the industries towards “Reduce, Reuse and Recycle” of the precious natural resource.
Plant overview
Kawas Gas Power Project An ISO 9001:2008; 14001:2004;OHSAS 18001:2007;SA 8000 :2008
Location Hazira-Surat-Gujarat
Installed Capacity Stage-I 656.2MW (2 CC Modules)
Type Combined Cycle Gas Power Plant
Gas Turbines 4 Nos. GE 9001 E 106 MW
Steam Turbines 2 Nos. Alsthom Rateau 116.1MW
Fuels Natural Gas: RLNG: Naphtha: HSD
Source of Water River Tapti. Pump House at Variav
Evacuation Thru’ 220 KV Transmission lines
Beneficiaries Gujarat, MP, Maharashtra ,DNH Chhattisgarh, Daman & Diu
NTPC Kawas (Stage - I) An ISO 9001:2008; 14001:2004; OHSAS 18001:2007; SA 8000 :2008
SOURCE OF WATER
Since commissioning of the plant in 1993. Raw water for the project was sourced through irrigation canal of river tapi flowing very near of the plant
NTPC, Kawas along with other industries of Hazira belt and Surat Municipal Corporation constructed a weir at Siganpore Weir in 1996 (around 18 km away from the project)
Raw Water fed through Intake channel up to Two Reservoirs of Capacity approx. 18.5 Lac Cu.M, with Water distribution in the ratio of 1:4.
Since then Water is drawn from Siganpore Weir ( Upstream of River Tapi) at Variav through 16 KM pipeline having pumping capacity of 1500 Cu. M/Hr.
Reservoir Capacity ( Lacs CuM) at 3.9 meters depth
Capacity ( Lacs CuM) at normal operational [ 2.5 m]
Retention Time ( Days)
Live 4.69 2.9 14 days
Dead 13.93 8.78 44 days
In 1996 Gujarat Government intimated its inability to continue the supply of water from the irrigation canal to the project due to rapid industrialization in the Surat region
Variav Pump House
NTPC KAWAS
WATER USAGE AREA AT PLANT
• 680 M3/hr • 45 M3/hr
• 45 M3/hr
• 50 M3/hr
DM Water
(For cycle & non cycle makeup)
Drinking
Water (plant &
township)
Make up to
Cooling water
system
Service
Water
Average Daily water usage of 21000 M3/Day when plant runs at full load
WATER CONSUMPTION PATTERN
Year
Total Water Consumption
(M3) Generation (MU)
Specific water consumption
[L/KWhr]
2010-11 6759893 3882.114 1.741
2011-12 6611950 3608.422 1.832
2012-13 3585786 2193.878 1.634
1.500
1.550
1.600
1.650
1.700
1.750
1.800
1.850
2010-11 2011-12 2012-13
Specific water consumption [L/KWhr]
WATER CHARGES AT KAWAS
This incremental hike @ 10 % in water charges is likely to get double @ Rs 28 – 30 / CuM from next FY 2013-14 as per recent proposal put up in front of state government after exhaustive survey & deliberation
done during a study carried out by a reputed institute.
WATER CHARGES CALCULATION
Particular As on Jan 2013 Anticipated by FY 2013-14
charges for water drawn through VARIAV pump house, Ave.18000 M3/Day
@Rs. 14.34 per M3 @ Rs. 28.68 per M3
Chemical Cost @Rs. 1.23 per M3 @Rs. 1.23 per M3
Water Cess @Rs. 0.05 per M3 @Rs. 0.05 per M3
Pumping & Maint cost & Variav pump house Ave. Rs 20 Lac/Month
@Rs. 3.70 per M3 @Rs. 3.70 per M3
Industrial water cost to site @Rs. 18.09 per M3 @Rs. 18.09 per M3
Process water cost inclusive of chemical @Rs. 19.32 per M3 @Rs. 33.66 per M3
NTPC KAWAS Financial figures of last 3 yrs (in Crores)
YEAR O&M Cost Station overheads Water charges
% of Overheads
2009-10 70.32 27.66 7.07 24.6 %
2010-11 84.28 30.88 7.43 24.5%
2011-12 85.78 31.18 7.79 25.1%
IMPACT OF WATER CHARGES ON PROFITIBILITY
Profit of Project = FIXED COST RECOVERY +MARGINAL GAIN-EXPENSES
O&M Cost Is the Major Component of EXPENSES
WATER CHARGES plays a significant role in the profitability of project
Decrease in WATER CHARGES can increase the profit of plant
INITIATIVES TAKEN TO REDUCE WATER CONSUMPTION
• WATER CONSERVATION THROUGH INCREASE IN COC FROM 1.65 TO 5.0
• SWAS RECYCLE
• USAGE OF CW BLOWDOWN FOR HORTICULTURE PURPOSE
• CHECKING OF WHRB V/V PASSING DURING SHUTDOWN
INCREASE IN COC FROM 1.65 TO 5.0
As per the design COC of 1.65 the water requirement was @ 2000 m3/hr
In the year 1996 the water source is shifted to Singpaur Weir at 18km
It forced to think on reduce the plant make up by operating the Circulating water system at a higher Cycles of Concentration (COC)
Site filtration skid to for continuous filtration of 1.25% of CW Water (1050 M3/hr) & Dedicated CW Chemical Treatment plant was commissioned to maintain the water quality
COC was increased to 5.0 from design of 1.65
WATER SAVING = 1000 M3/HR (50% of Original consumption)
Recycling of SWAS Drains
Original Header of
SWAS Drains
New Header of
SWAS Drains
WATER SAVING 20 M3/DAY
TAPPING TAKEN FROM CW BLOW DOWN LINE FOR HORTICULTURE USAGE
WATER SAVING 45 M3/DAY
CW WATER USED FOR HORTICULTURE USING WATER
SPRINKLERS
IDENTIFICATION OF V/V PASSING
INITIATIVES TAKEN FOR IMPROVEMENT IN WATER QUALITY
• ISOLATION OF DEAD RESERVOIR
• SEPARTAION OF CLARRIFER
• ULTRA FILTRATION SYSTEM IN TOWNSHIP.
• REPLACEMENT OF DRINKING WATER/SERVICE WATER PIPELINES
PROBLEM OF DEAD RESERVOIR WATER QUALITY
– Deterioration in Raw Water Quality • Increased industrialization
• Non release of water to Tapti river.
– Increased C0C to 5 from Design value of 1.65 • Increased stagnation time in reservoir due to low water
requirement
• Plant Water requirement reduced @ ~ 1000 M3/Hr from design
– Carry over of High Organics present in raw water and that originated from casurina trees to Dead reservoir.
– Due to High Retention Time ( > 30 days) in dead reservoir, Concentration of Organics are getting multiplicated.
Earlier water quality at Dead Reservoir
After water quality at Dead Reservoir
Impact of Dead Reservoir Water on the Plant Process & Other Systems
• Severe Foaming in CW Forbay.
• Organic fouling / deposits in condenser tubes
• Disturbance in boiler chemistry due to carry over of organics to drums .
• Difficult to maintain ACC < 0.3 uS/cm
• Deterioration in MB o/l Quality.
• Difficult to achieve Cond < 0.3 uS/cm
• Reduction in OBR of DM Plant from 600 to 250 M3 .
• Specific Consumption of Chemicals increased.
• Red Worms Problems
Drinking Water
DM Plant
CW System
Boiler Cycle
Various steps done to improve water quality
Improvement observed in the various processes.
Dead Reservoir has been isolated since Jan’2009.
It has been decided to Isolate Dead reservoir & fresh water to be taken through live reservoir only.
Joint Committee of M/s NETRA and Site representatives did a comprehensive study
Benchmarks achieved in Quality of Water in 2012
• MB Outlet conductivity of 0.051 uS/cm
• DM Storage Tank Outlet conductivity of 0.22 uS/cm.
• After Cation Conductivity (ACC) of 0.09 uS/cm in SWAS system
SEPARATION OF CLARIFIER
• Common outlet channel of two clarifiers has been separated.
• One clarifier is used for DM & Potable Water System @ 20 -30 % design flow to increase retention time thereby improving the clarification process
• Other clarifier is used for make up to CW system.
Better Organic
&
Turbidity Control
Separation of clarifiers
New outlet line Laid for Clarifier -02
This modification of isolation of clarifiers has resulted in significant improvement in the DM water quality and maintaining ACC in the boilers.
•1st in any NTPC Station •Specifically dedicated for drinking water purpose •Consist of Carbon filter, micro filter, UF Skid & storage tanks
ULTRA FILTERATION PLANT OPERATIONAL & PERFORMANCE REPORT OF JAN-2013
SCHEME OF EFFLUENT DISCHARGE AT JHANOR
Year Effluent discharged (M3) DM Water Consumption (M3) DM water
consumption as %
of Effluent disposed
2009-10 1350930 890668 66%
2010-11 1203365 745020 61.9%
2011-12 1054935 532369 50.4%
PIL PILOT UNIT SCHEME
A pilot study was conducted at site by M/s Pall Filtrations with MF+RO combination skid to treat CW blow down water, which is the major constituent of the combined effluent.
PIL OUTCOME OF PILOT STUDY AT JHANOR
The quality of output from MF+RO skid w.r.t chemical parameters is such that it can be directly used as inlet to DM Plant for polishing and further use. It can reduced water consumption by 60% Recycling the effluents, in this manner, will fetch benefits in terms of reduced chemical consumption in DM plant, lower power consumption in the effluent disposal system and a big leap towards zero discharge.
On similar lines, NTPC Kawas has also initiated proposal for
recycling the CW Blow Down water @ 150 – 200 M3/Hr and utilizing
the same in CW system as make up, which will reduce the fresh
water consumption of the plant by ~ 20 % and effluent generation
will be reduced by ~ 75 %.
VARIOUS STUDIES DONE TO CONSERVE WATER
• RAIN WATER HARVESTING IN YEAR 2012-13
• WATER BALANCE STUDY WITH THE HELP OF THERMAX 2011-12
• STUDY OF BTF LEAKAGE PROBLEM THROUGH CMI, BELGIUM IN YEAR 2012-13
• CANAL TOP SOLAR PROJECT FOR RAW WATER CANAL YR 2012-13
RAIN WATER HARVESTING STUDY
Study being carried through M/s Furaat Earth Pvt ltd, Ahedabad to assess the potential of rain water harvesting at NTPC – Kawas Report envisages that with average rainfall of 1300 mm @ coefficient of 60 %, there is potential to harvest approx 18 lacs M3 of rain water considering the entire plant area of 560 acres. Report has identified following three potential points from where the rain water can be harvested. •COOLING BAY •OPEN INTAKE CHANNEL •ROOF TOP RAIN WATER FROM BUILDING
RAIN WATER HARVESTING STUDY
MODULAR SYSTEM FOR ROOF TOP WATER HARVESTING
WATER BALANCE STUDY BY THERMAX
A comprehensive Water Balance Study was carried out in 2011 - 12 by M/s Thermax – To assess the gaps in the various
process water consumption / usage pattern
– To identify the areas for recycling of the effluents
– To improve the overall efficiency of the plant through installation of energy efficient devices, wherever applicable.
STUDY OF BTF LEAKAGE PROBLEM THROUGH CMI, BELGIUM
• OEM of WHRB, M/s CMI, Belgium was awarded
to study the boiler tube leakage problem at Kawas.
• CMI representative visited site for study & assessment of problem.
• Observation of Comprehensive Report:- – HP2 SHT Inlet Header to be relocated to be modified
for complete draining during shut downs. – Provision of extra drain valves before & after
Desuperheating temperature control valves.
FEASIBILITY STUDY OF CANAL TOP SOLAR PROJECT AT NTPC KAWAS
Feasibility Report
Canal Top solar project is feasible.
Expected cost of project = Rs 4 Crores
Expected Solar Output of project = 0.3 MW
Installation Time = 6-8 months from LOA
Site Feasibility survey has been completed by M/s Sunedison (I) Ltd [ Party who has carried out India’s 1st Canal Top Solar
Project].
Canal Top Solar project has been identified as S.D. Project of Kawas.
PAY BACK PERIOD OF VARIOUS INITIATIVES
Initiative Actual/anticipated water saving /yr
Approx. Initial Cost
Pay Back period
Running at higher COC of 5 compare to design of 1.65
87.6 Lacs M3 2.5 Crores 6 months
Recycling of cooling water blow down water for horticulture purposes
0.164 Lacs M3 0.5 Lacs 2 months
Recycling of SWAS drains 0.073 Lacs M3 0.5 Lacs 4 months Rain water Harvesting 6 Lacs M3 10.0 Lacs 2 months Recycling of CW Blow down to achieve ZERO EFFLUENT DISCHARGE
14 Lac M3 21 Crores 7 years
TOGETHER WE CAN TOGETHER WE WILL
MAKE THE DIFFERENCE
Thank you!
Comparison of Water Charges in Western Region
This incremental hike @ 10 % in water charges is likely to get double @ Rs 28 – 30 / CuM from next FY 2013-14 as per recent proposal put up in front of state government after exhaustive survey & deliberation
done during a study carried out by a reputed institute.
State Project name Water Charges ( Rs / CuM)
Madhya Pradesh Vindhyachal 4.00
Chhattisgarh Korba, Sipat 7.24
Gujarat Kawas, Jhanor 14.64