Environmental Impact Assessment

(EIA)

of

Thermal Power Plant

By:-

Vandana Bharti

Department of Environmental Engineering

Ch. B.P. Government Engineering College

New Delhi (India)

1

2

SUMMARY TABLE OF ELECTRIC POWER

GENERATION

3

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

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 .

4

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

5

6

PROCESS

7

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.

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.

8

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.

9

10

11

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

12

POLLUTION LOAD FROM COAL

BASED THERMAL POWER PLANT

13

Pollutants Emissions (in tones/day)

CO2 424650

Particulate

Matter

4374

SO2 3311

NOx 4966

Ref:-CPCB

2012

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 : 03Ref:-CPCB

2012

14

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

15

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

16

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

17

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

18

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

19

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

20

IMPACT ANALYSIS

→ Type biophysical, social, health or economic

→ Nature direct or indirect, cumulative, etc.

→ Magnitude or

severityhigh, 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

21

TOOLS FOR IMPACT ANALYSIS

checklists

matrices

networks

overlays and geographical information systems (GIS)

expert systems

professional judgement

22

IMPACT MITIGATION

to avoid, minimise or remedy adverse

impacts

to ensure that residual impacts are within

acceptable levels

to enhance environmental and social

benefits 23

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

24

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)25

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

26

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:-

27

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

28