Environmental Issues Associated With a Thermal Power Plant

1. Environmental Impact Assessment
(EIA)
of
Thermal Power Plant
By:-
Vandana Bharti
Department of Environmental Engineering
Ch. B.P. Government Engineering College
New Delhi (India)
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3. SUMMARY TABLE OF ELECTRIC POWER
GENERATION
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Source India Japan U.S.
Coal 59.2% 21.2% 51.8%
Oil 13.9% 16.6% 03.1%
Gas 06.3% 22.1% 15.7%
Nuclear 02.5% 30.0% 19.9%
Hydro 17.8% 08.2% 07.4%
Others 00.3% 01.9% 02.2%
Ref:-CPCB-2012

4. INTRODUCTION
 A thermal power station is a power plant in which
the prime mover is steam driven. Water is heated,
turns into steam and spins a steam turbine which
drives an electrical generator.
 After it passes through the turbine, the steam is
condensed in a condenser and recycled to where it
was heated; this is known as a Rankine cycle .
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5. MECHANICAL DESIGN
• Boiler.
• Furnace.
• Turbine.
• Super Heater & Re- Heater.
• PA,FD & ID Fan.
• Cooling Tower
FUNCTION HELD IN PLANT
• Coal Flow
• Steam Flow
• Water Flow
• Ash Handeling
FEED WATER SYSTEM
• High Pressure Heaters
• Boiler Feed Pump (BFP)
• Feed Regulating System
• Drip & Drain System
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7. PROCESS
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 Coal supply
After haulers drop off the coal, a set of crusher and
conveyor prepare and deliver the coal to the power
plant. When the plant need coal, coal hopper crush coal
to a few inches in size and the conveyor belt bringing
the coal inside.
 WAGON TIPPLER:
It is the machine which is used to tip the coal from the
wagon. The coal tipped is directly feed to conveyor belt.
Its capacity is 12 wagon per hour.
 CRUSHER:
It crushes the coal into small pieces.
 COAL MILLS:
In it small pieces of coal are converted into pulverized
from.

8.  FURNACE:
It is the chamber in which fuel burns & fire blows.
 BOILER DRUM:
It contains water for boiling.
 ELECTROSTATIC PRECIPITATOR:
In this we have electrodes which attract fly ash and extract it
from flue gases so that it cannot enter atmosphere.
 CHIMENY:
It is used to release flue gases into the atmosphere.
 TURBINE:
Turbine is the part which revolves due to steam pressure. It is of
three types.
a) High pressure turbine.
b) Intermediate pressure turbine.
c) Low pressure turbine.
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9.  TURBO GENERATOR:
It is the main machine which produces250 MW electricity .
 CONDENSER:
It condenses steam coming from low pressure turbine (L.P.T.) to
hot water. By removing air and other non-condensable gases
from steam while passing through them.
 COOLING WATER (C.W.) PUMP:
This pump send water from cooling tower to condenser.
 COOLING TOWER:
It is used to cool the water its height is near about 143.5 mtrs.
The hot water is led to the tower top and falls down through the
tower and is broken into small particles while passing over the
baffing devices. Air enters the tower from the bottom and flow
upwards. The air vaporizes a small percentage of water,
thereby cooling water falls down into tank below the tower from
where it is pumped to the condenser and cycle is repeated.
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12. Air Pollution :-High particulate matter emission levels due to burning
of inferior grade coal which leads to generation
of large quantity of flyash
Emissions of SO2, NOx & Green house gas (CO2) are also
matter of concern
Water Pollution :- Mainly caused by the effluent discharge from ash
ponds, condenser cooling /cooling tower, DM
plant and Boiler blow down.
Noise Pollution :- High noise levels due to release of high pressure
steam and running of fans and motors
Land Degradation :- About 100 million tonnes of fly ash is generated by
use of coal far energy production. The disposal of such large
quantity of fly ash has occupied thousands
hectares of land which includes agricultural
and forest land too.
ENVIRONMENTAL ISSUES IN COAL BASED POWER GENERATION
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13. POLLUTION LOAD FROM COAL
BASED THERMAL POWER PLANT
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Pollutants Emissions (in tones/day)
CO2 424650
Particulate
Matter
4374
SO2 3311
NOx 4966
Ref:-CPCB
2012

14. Status of Pollution Control in Thermal Power
Plants in India
Total number of power plants : 81
Air Pollution
 Power plants complying with emission : 43
standards
 Power plants not complying with emission : 35
standards
 Power plants closed : 03
Water Pollution
 Power plants complying with ash pond : 49
Effluent standards
 Power plants not complying with ash pond : 29
Effluent standards
 Power plants closed : 03
Ref:-CPCB
2012
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15. Activities involved and their Impacts
Change in land use pattern/ Site clearing:-
•Erosion
•Loss of biodiversity
•Loss or change of soil quality and quantity
•Huge diversion and acquisition of land in case of power plant with Captive mining
Civil works:-
•Dust pollution
•Noise pollution
Operational Activities:-
•Air pollution
•Waste generation
•Water consumption
•Emission of mercury
•Greenhouse emission
Local biodiversity
Solid waste management
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16. Activities involved and their Impacts
Air pollution from point sources:-
Particulate matter, Gaseous emission- SOx,, NOx,CO, CO2, hydrocarbon etc…
Air pollution from non-point sources:-
Transport of coal, loading/unloading, coal storage, fly-ash handeling
Sources of water pollution:-
Cooling tower blow down, Boiler blow down, Demineralisation (DM), plant effluent,
Leachate of heavy metal (ash pond) contaminate ground water, Effluent from oil handeling
and transformer areas, power house and turbine Area Effluent , Domestic waste water
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17. REASONS FOR NON-COMPLIANCE OF
ENVIRONMENTAL STANDARDS IN
THERMAL POWER PLANTS
Inconsistent supply of coal
High resistivity of coal
Inefficient operation of ESPs
Delay in supply of ESPs
Low Specific Collection Area (SCA) of ESPs
Inefficient management of ash ponds
Large quantities of ash generation
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18. An Indian Case Study
On
Comprehensive EIA
Of
THERMAL POWER PLANT
at
Raigarh district of Chattisgarh
by
Jindal Steel and Power Ltd (JSPL)
For better understanding of EIA
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19. Project Proposal
• JSPL is operating a open cast coal mine, along with
Crushing, Screening and Washing plant
•JSPL is now proposing to set up a 2*150 MW thermal power
plant which will use the middling and coal fines generated
during coal washing as Raw material
•The company runs a steel plant in Raigarh and proposes to
transmit the power generated by this thermal power plant to
its steel plant through its own dedicated transmission network
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20. Salient features of the project
Location
Village- Dongamahua, 50kms away from Raigarh
The KELO river flows at a distance of around 3.5 kms from this proposed site.
There are many seasonal drains and tributeries of the Kelo, which ultemately merge
into the river
Fuel
Coal
Requires 2.47 million tonnes of coal per annum (@ 312tonnes/hr for 330 days)
Middlings and coal fines will be tranported to plant site via road or conveyor belts
The project will also require some light diesel oil (LDO)
Water Requirement
7.46 MCM which will be sourced from ground water collected in the mine sump, and
from bore borewell
Land use
Requires 56 acres (22.7 hectares of land), Flat topography, either agricultural or
wasteland
Human habitation
94 inhabited revenue villages
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21. IMPACT ANALYSIS
→ Type biophysical, social, health or economic
→ Nature direct or indirect, cumulative, etc.
→ Magnitude or
severity
high, moderate, low
→ Extent local, regional, trans-boundary or global
→ Timing immediate/long term
→ Duration temporary/permanent
→ Uncertainty low likelihood/high probability
→ Reversibility reversible/irreversible
→ Significance* unimportant/important
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22. TOOLS FOR IMPACT ANALYSIS
 checklists
 matrices
 networks
 overlays and geographical information systems
(GIS)
 expert systems
 professional judgement
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23. IMPACT MITIGATION
 to avoid, minimise or remedy adverse
impacts
 to ensure that residual impacts are within
acceptable levels
 to enhance environmental and social
benefits
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24. FRAMEWORK FOR IMPACT MITIGATION
Common (desirable)
Rare (undesirable)
Alternative sites or
technology to
eliminate habitat loss
Actions during
design, construction and
operation to minimise
or eliminate habitat
loss
Used as a last resort
to offset habitat loss
Avoidance
Mitigation
Compensation
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25. REPORTING
Different name of EIA reports
 Environmental Impact Assessment Report (EIA
Report)
 Environmental Impact Statement (EIS)
 Environmental Statement (ES)
 Environmental Assessment Report (EA Report)
 Environmental Effects Statement (EES)
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26. Remediation Measures in Thermal power plant
Air pollution control:-
For boiler stacks ESP/ Bag house
Coal crusher Bag filter
Coal mill Bag filter
SOx control:-
Use of alternative fuel
Low sulphur containing fuel
Lime dosing
High stack
NOx control:-
Ammonia injection
Low NOx burner
Flue gas recirculation
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27. Remediation Measures in Thermal power plant
Fugitive Dust control:-
Covered storage yard for coal
Closed unloading of coal with adequate dust suction device
Closed conveyor belt for transportation of raw
Fly ash management:-
Ash disposal site should be lined to prevent metal contamination
Construction of green barrier all around the ash pond
Construction of piezometric holes
Recycling of ash pond effluents
New technologies practices:-
Water conservation techniques:-
Practices to reduce transportation impact:-
Practices for soil management:-
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28. REFRENCES:-
1. CPCB
2. An India case study on Thermal power plants
3. International journal of Environmental Engineering and management
4. www.envfor.nic.in
5. www.harmo.org/confrences
6. www.environmental-experts.com
7. Dr. Amit Jain
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