NORMS FOR EMISSION OF SOx, NOx, SPM & MERCURY FROM THERMAL POWER PLANTS

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  • The notification from MoEF & CC dated 7th December-2015 amends existing norms related to emission of SPM and introduces new norms for emission of SO2, NOx and Mercury from Thermal Power Plants (TPPs).
  • It also specifies modified limits for specific water consumption by TPPs.
  • To convert existing once through based condenser cooling system to recirculation type.
  • Different limits are specified based on capacity of power plant and year of installation.

 NEW REGULATIONS ON EMISSION

A summary of new regulations on air emission is given in below:


Date of
Installation

PM

SO2

Nox

Mercury (Hg)

Before
31-12 -2003

100 mg/Nm3

600 mg/Nm3 for <500MW

600 mg/Nm3

0.03 mg/Nm3 for >=500MW

200 mg/Nm3 for >=500MW

After 01-01-2003 & Upto 31-12-2016

50 mg/Nm3

600 mg/Nm3 for <500 MW

300 mg/Nm3

0.03 mg/Nm3 for >=500MW

200 mg/Nm3 for >=500MW

0.03 mg/Nm3

On or after 01-01-2017

30 mg/Nm3

100 mg/Nm3

100 mg/Nm3

0.03 mg/Nm3

 NEW REGULATION ON WATER USE

All plants with Once through Cooling (OTC) shall install Cooling Tower (CT) and achieve specific water consumption up to maximum of 3.5 m3 /MWh within a period of two years from the date of publication of notification.
All existing CT-based plants reduce specific water consumption up to maximum of 3.5 m3 /MWh within a period of two years from the date of publication of notification.
New plants to be installed after 1st January 2017 shall have to meet specific water consumption up to maximum of 2.5 m3 /MWh and achieve zero waste water discharged.

MOEF & CC HAS SUBSEQUENTLY ISSUED AN AMENDMENT DATED 28 TH JUNE 2018 FOR STACK HEIGHT POST FGD AND WATER CONSUMPTION WHICH IS MENTIONED BELOW:


INDUSTRY

PARAMETER

STANDARDS

TPS with FGD
stack height /limit in meters

Power Generation capacity :

100 MW and above
 H = 6.902 (QX0.277)0.555
 Or
 100 m Whichever is more

Less than 100 MW H = 6.902 (QX0.277)0.555 Or 30 m Whichever is more

Q = Emission rate of SO2 in kg/hr*

H = Physical stack height in meter

*Total of the all units connected to stack

Note: These standards shall apply to coal /lignite based Thermal Power Plant.
  • All monitored values for SO2 and NOx shall be corrected to 6% Oxygen, on dry basis. 
  • Specific water consumption shall not exceed maximum of 3.0 m3/MWh for new plants installed after the 1st January 2017 and these plants shall also achieve zero waste water discharge.
  • Seawater based plants are exempted from conversion of once through to Cooling Tower based system

The SO2 reduction technology shall be done considering following factors:

1: Sulphur Content in Coal.
2: SO2 removal Efficiency requirement of particular plant.
3: Availability of Reagent (if Any).
4: Disposal and handling of By-product.
5: Locational/Geographical factors of the plant.
6: Plant life.
7: Space requirement for FGD facility

AUXILIARY POWER CONSUMPTION for FGD:

Auxiliary Power Consumption (APC) is estimated to be maximum 1% for FGD operations. In case GGH (Gas to Gas Heater) is used maximum 0.3% additional APC may be required.


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