Regulatory requirements on the utilisation of Fly Ash from Thermal Power Plants in India

In order to reduce the land requirement for disposal and the environmental impacts of Fly Ash generating from TPPs in India, the Government of India have taken several steps. One of the measures is utilisation of Fly ash in a phased manner.

The target of achieving 100% Fly ash utilisation in a progressive manner is specified by MoEF notification dated
3/11/2009 for all Coal/Lignite based TPPs.

Successive Years   Prescribed Targets
                                        of FA utilisation for
                                         TPPs in operation                                                      before 3/11/2009                                                                                       
1st year                             50%
2nd year                           60%
3rd year                            75%
4th year                             90%
5th year                            100%

(Such TPPs will have to achieve 100% target in successive 5yrs from the date of this notification, 3.11.2009)


Successive Years         Prescribed Targets
                                          of FA utilisation for
                                          TPPs in operation                                                      after 3/11/2009
                                                                      
1st year                              50%
2nd year                            70%
3rd year                             90%
4th year                             100%

(Such TPPs will have to achieve 100% target in successive 4yrs from the date of commissioning)

MoEF has come up with new notification No. S.O. 254(E) dated 27.01.2017, for promoting the utilisation of Fly Ash. The notified points are given below
1. Fly ash based products shall be used by all construction agencies in every construction projects, within the radius of 300Kms from Coal/Lignite based TPPs. 
2. Cost of transportation of Fly Ash to interested parties, within the radius of 100Km from TPPs, shall be borne by such TPPs. Whereas between 100-300Kms, the cost shall be shared equally between the User & TPPs.
3. Detailed information of Stocks of each type of Fly Ash available with the TPPs, be uploaded on their website, within 3 months from the date of notification 27.01.2016. This information about the stock shall be updated thereafter atleast once in a month.

Requirement or Criteria on the use of Beneficiated/Blended Coal in Thermal Power Plants in India

In order to minimise Fly Ash generation, MoEF, GOI notified on 2/1/2014 (vide Gazette Notification GSR 02(E) on the use of Beneficiated coal containing Ash not more than 34% on quarterly average basis in the following TPPs depending on their Location.

1)   A stand-alone TPPs of any capacity
                                    or
 Captive PPs of installed capacity of  100MW or above

Located beyond 1000 Km from Pit-head  area
                                     or
Located in an Urban area
                                    or
Located in an ecologicaly sensitive area 
                                    or 
Located in a critically polluted Industrial area, irrespective of its distance from Pit-head area 

except Pit-head TPPs with an immediate effect.

2)  A stand-alone TPPs of any capacity
                                    or
 Captive PPs of installed capacity of  100MW or above

Located between 750-1000 Km from Pit-head 

 with effect from 1/1/2015.

3) A stand-alone TPPs of any capacity
                                    or
 Captive PPs of installed capacity of          100MW or above

Located between 500-749 Km from Pit-head

with effect from 5/6/2016.


The following Technologies or the Green /Clean technologies or any other technology approved by MoEF, used in TPPs, are exempted from use of Beneficiated Coal irrespective of their locations.

The technologies are
Power plants using
1. Circulating Fluidised based combustion or 2. Atmosphere Fluidised based combustion or
3. Pressurised Fluidised bed combustion or
4. Integrated Gasification combined cycle technologies.
5. Supercritical Power Plant

Stack Height Requirement for Thermal Power Plants in India

Stack Height (Limit) criteria for Coal based Thermal Power Plants have been developed in India, based on proper dispersion of SO2 emissions from TPPs in Ambient Air.

For TPPs having Boiler Capacity more than 500 MW and above, space provision for installing FGD has been recommended.

TPPs having              Stack Height in Mtrs
Capacity (MW)

1. < 200/210                Height in Mtrs= 14Q<sup>0.3 
2. 200/210 to < 500       220 Mtrs
3. 500 MW & above       275 Mtrs</sup>

Q is SO2 Emission rate from stack in Kg/Hr





There are some requirements for TPPs sanctioned earlier to 1 June 1994 with regards to stack height.

Such TPPs may not be required to increase the existing height subject to the following conditions:-

1. The ambient SOx & Nox concentration     levels is less than 1/3 th of the prescribed air quality standards for SOx & NOx for the Concerned Area.

2. Such TPPs shall install adequate no.of Air quality monitoring stations in & around the Power plant area. These Monitoring station be selected in consultation with SPCB/CPCB.

Existing and New (Revised) Emission Standards for coal based Thermal Power Plants in India

Existing and New (Revised) Emission Standards for coal based Thermal Power Plants(TPPs) in India

Existing Emission Standards:

Particulate Matter (PM) Emission

Parameter        Standard Limits, mg/Nm3

PM                    350 (for <210 MW TPPs)

PM                    150 (for 210 & above MW TPPs

New Emission Standards as per MoEF Notification dated 7.12.2015 :-

1) For new TPPs to be  installed after 1/1/2017. These units includes all those TPPs which have got EC and are under construction.

Parameter                   Standard Limits, mg/Nm3

PM                                         30

SO2                                       100

Oxides of Nitrogen(NOx)  100

Hg                                         0.03

2) For TPPs installed between 1/1/2003 to       31/12/2016, these units have to meet the limits   within two years from the date of MoEF Notification (7/12/2015)

Parameter             Standard Limits, mg/Nm3

PM                                       50

NOx                                    300

Hg                                       0.03

SO2     600 (for <500MW Power Plants)

SO2     200 (for Power Plants of 500MW & above)

3) For TPPs installed before 31/12/2003

Parameter       Standard Limits, mg/Nm3 

PM                         100

NOx                        600

Hg                          0.03

SO2     600 (for <500MW Power Plants)

SO2     200 (for Power Plants of 500MW & above)

Air pollutants Unit Conversion

The following is with reference to Air Pollutants,

(* means multiplication and,  / means division)

ppb :-   parts per billion by volume
ppm :-  parts per million by volume

Numbers

Million = 1,000,000

Billion = 1,000,000,000

Trillion = 1,000,000,000,000

1 ppm = 1000 ppb = 10^{3 ppb}
1 ppb = 0.001 ppm = 10^-3 ppm
1% = 10000 ppm
% = ppm * 10^{-4
% = (}10^{3 ppb *}10^{-4) = (ppb/10)}
 %= ppm * 10^-4 = ppb * 10<sup>-1

For concentrations  (of chemical contaminants or soil contaminants)  in water, in soil
the following holds true</sup>

1 ppm = (1 mg/Lit, like in water)= (1 mg/Kg, like for concentrations in soil) = (1gm/m³  like for concentration of chemicals in water)

same for ppb,

1 ppb = 1μg/Lit  = 1 μg/Kg = mg/m³ 

But for concentration of air pollutants in Air, following conversion formula is to be used,

mg/m³  is same as  mg/Nm^3
μg/m3  is same as  μg/Nm³

mg/Nm³ = (ppm * MW )/(0.08205 * °K)

where °K is Deg Kelvin and MW is 
molecular wt. of air pollutants

At 1 atm pressure and 25°C, the above equation becomes

mg/Nm³  = (ppm* MW)/24.45

or

μg/Nm³  = (ppb* MW)/24.45

Standard molar volume of an ideal gas at 1 atm pressure and 25°C temp = 24.45 m³/mol

and at 0°c this volume is 22.414 m³/mol

NAQI:- National Air Quality Index for India

NAQI
National Air Quality Index for India
There are Six (6) AQI categories like GOOD, SATISFACTORY, MODERATELY POLLUTED, POOR AIR QUALITY, VERY POOR AIR QUALITY, SEVERALLY POLLUTED. These AQI are integrated with AQI Sub-index (which is a range in real numbers). These six categories are decided based on Ambient concentration values of air pollutants & their likely health effects. The AQI sub index  and health impacts (health breakpoints) are evolved for eight (8) pollutants like PM10, PM2.5, NO2, SO2, CO, O3, NH3, Pb. 

NAQI standard are prescribed for these 8 pollutants for short term exposure (24hrs).  Sub-index is calculated based on ambient concentrations of these air pollutants. It is to be noted that AQI Sub-index is linear function of ambient concentrations of these 8 air pollutants.
The worst Sub-index determines Overall AQI.


AQI                         Possible Health impacts  
                        or health break point


Good -                    Minimum Impact
(0-50)

Satisfactory -        Minor Breathing
(51-100)                discomfort to
                               sensitive  persons

Moderately Polluted-  Breathing discomfort  
(101-200)                     to persons having Heart
                                      or Lung disease, to older
                                      ones & to children's

Poor -                     Breathing discomfort to
(201-300)              persons on prolonged
                               exposure 

Very Poor -            Respiratory illness to
(301-400)              people on prolonged
                               exposure 

Severe -               Respiratory effects even on
(>400)                  healthy people


One observation means one AQI calculated
for daily Ambient Air Quality data at
one Air Monitoring Station.



Air Pollutant      AQI Sub-index     Ambient        
                                                          concentration                                                                      of PM2.5

PM2.5                      100                  60 μg/m3
PM2.5                       75                   45 μg/m3
PM2.5                       50                   31μg/m3

Standards for Water Consumption in Thermal Power Plants in India

Standards for Water Consumption in Thermal Power Plants in India

1. All plants with Once Through Cooling (OTC) shall install cooling tower (CT) and achieve specific water consumption upto maximum of 3.5m3/MWh by 7/12/2017.

2. All existing Cooling Tower(CT) based plants reduce specific water consumption of 3.5m3/MWh by 7/12/2017.

3. New Plants to be installed after 1/1/2017 shall have to meet specific water consumption upto maximum of 2.5m3/MWh and achieve zero Wastewater discharge.