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TECHNOLOGY
ALTERNATIVES FOR THERMAL POWER PLANTS INDUSTRY IN INDIA
Thermal
Power Plants
Thermal Power
Plants can be classified based on the type of fuel used. The main categories
of the power plants are coal/lignite based; gas/Naphtha/oil based and Nuclear
power plants.
Coal/liquite
based thermal power plants
Particulate
matter, sulphurdioxide and oxides of nitrogen are the main pollutants emitted
form these plants which lead to air pollution. The suspended solids, oil
and grease are main pollutants in effluent generated besides higher temperature
in cooling water discharge.
The pollution
control systems in practice and the requirements are tabulated below :
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Technologies/Current
Practices
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Requirements
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Electrostatic
Precipitators have been provided to control the emission of particulate
matter with appropriate stack height for adequate dispersion of gaseous
pollutants.
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High efficiency
ESPs with EPIC controller should be provided. Further, based on background
concentration or future development of power generation in cluster areas,
space provision for installation of flue Gas Desulphurisation (FGD) system
and DeNOx system, for control of SO and NOx emissions are needed so that
the same control be provided where needed. For controlling smaller particulate
emissions from stacks i.e. PM10/PM2.5, bag filters may be used as ESP would
not trap small particles efficiently. Bag filters may also be used in combination
with mechanical collectors or ESPs.
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To reduce ash
content in coal, use of beneficiated coal has been made mandatory w.e.f.
June 2001.
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Fluidised Bed
combustion (FBC)/CFBC technology for the solid fuel containing higher ash
and sulphur.
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Integrated Coal
Gasification combined cycle (IGCC) technology should be tried.
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Wet ash disposal
system (lean phase) has been adopted. Some of the plants have dry ash disposal/collection
system vis-a-vis wet disposal in ash pond with wastewater recycling system.
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Dense Phase wet
ash disposal system. Ash pond wastewater should by recycled hundred percent
by the new plants.
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To promote utilisation
of flyash, provision for dry collection and storage (Silos) should be made
an integral part of the ash management system.
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Once through cooling
system is in practice in some plants. However, new plants have provided
cooling towers (which discharge less quantity of hot water)
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In water scarce
areas and in locations where power plants are sited near lakes/reservoir,
cooling towers should be provided.
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Gas/naphtha based
Thermal Power Plants
Oxides of nitrogen
and noise are the main pollutants from these plants. In combined cycle
power plants, cooling water discharge at high temperature is a problem
for the recipient water bodies.
The available
and required pollution control measures in such plants are tabulated below
:
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Technologies/Current
Practices
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Requirements
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Low NOx burner
and steam injection for control of oxides of nitrogen.
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Turbines in acoustic
enclosures (in door) to control noise.
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Once through cooling
system
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High efficiency
catalysts based fuel gas denitrification (selective catalytic reduction,
SCR) system.
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Low noise and
low vibration turbines.
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SOURCE:
CENTRAL POLLUTION CONTROL BOARD
DATE:
22nd NOVEMBER, 2000
KEYWORDS
:
TECHNOLOGY
ALTERNATIVES, ALTERNATIVE TECHNOLOGIES, BEST PRACTICES, INDIAN INDUSTRY,
TECHNOLOGY TIPS, POLLUTION CONTROL, CENTRAL POLLUTION CONTROL BOARD, CPCB,
TECHNOLOGY OPTIONS, THERMAL POWER PLANTS INDUSTRY, THERMAL POWER PLANTS |