ENVIRONMENT & COAL/ASH HANDLING : GOVERNMENTS

INITATIVES IN INDIABy

Ms Sanchita JindalFormer Adviser (Scientist G) & Director (T)-HSMD

Ministry of Environment, Forests and Climate ChangeGovernment of India

Presentation For Conference on TTP – O&M by Mission Energy Foundation

Indian Power Scenario

• Indian power sector grown from an installed capacity of 1,713MW in 1950’s to 3,49,288 MW as on 31st December, 2018.

• About 25% of Indian Population doesn’t have access toelectricity.

• Planning Commission projected addition of about 120 GW ofCoal based capacity during 2012-2022 i.e. double the existingcapacity and by 2031, an addition of 600GW capacity.

• India’s per capita consumption of electricity was about914kWh in 2012-13- about one third of the world’s average

Indian Power Scenario

• Power generation is about 75% of Thermal (coal, Gas & Oilbased), about 10% of Hydro, about 2.38 % of Nuclear andabout 13.5% of Renewable Energy Sources.

• Out of the thermal- about 70% is coal based.

• China – the world’s largest power producer- surpasses the US and 78% is Coal based.

• During 2011-35, bulk growth in coal based electricity would be in China and India.

• India’s development Objectives- 8% growth rate for 25 years

Indian Power Scenario

• The National Electricity Plan of 2018 by GoI- thecountry does not need additional non-renewablepower plants in the utility sector until 2027, with thecommissioning of 50,025 MW coal-based power plantsunder construction and achieving 275,000 MW totalinstalled renewable power capacity after retirement ofnearly 48,000 MW old coal fired plants

Coal: The Backbone of PowerAND BIGGEST SOURCE OF POLLUTION

• In India , for another two decades , Coal will be the primary source of electricity- the most viable source.

• Chattisgarh, Odisha, Jharkhand, West Bengal and MP are the main power states. Maharashtra, Andhra Pradesh and Tamil Nadu – the future capacities-Coastal capacities in Gujarat also.

• ‘Cradle- to – Grave’ - Coal Mining – the biggest source of pollution.

Coal: The Backbone of PowerAND BIGGEST SOURCE OF POLLUTION

• Poor Quality of Coal- 35-40% of Ash content and low calorific value.

• Coal mining – huge forest land diversion• Coal mining regions – air pollution hot spots-

Korba, Singrauli and Dhanbad- critically polluted zones- high fugitive dust

• 10% of human related emissions of methane is from Coal Mining

• Huge waste in coal mining - 1:4

Environmental Issues

Air Pollution• Emission of particulate matter (dust)• Emission of Sulphur Dioxide and Oxides of Nitrogen• Green House Gas Emissions• Emission of Mercury (both gaseous and in ash)• Fugitive emission of suspended particulate matter from CHP,

Wagon Tripler and ash pondWater Pollution (A very water intensive industry) • Cooling water discharge at higher temperature- affects

marine/aquatic life• Ash pond effluent• Coal Washing• Shop floor washingSolid Waste ( use of high ash containing coal)• Large volume of coal ash generation (Flyash & Bottom ash)• Large land requirement for ash disposal

AIR POLLUTION FROM THERMAL POWER PLANTS

• Coal combustion- CO2, SOx, NOx, Heavy Metals, Hg, Fly Ash

• Highest Green House Gas emitter sector- 53 % of CO2 emission in India from burning fuel is caused by electricity generation

• GHG highest- low efficiency- 1.08 kg CO2/kWh compared to China and USA –0.95 kg/kWh

Estimated Sulphur Dioxide emission (Industrial sector wise)

Estimated mercury emission(Industrial sector wise)

Causes of Air Pollution fromTTPs

• Poor Quality Coal• Poor Combustion Efficiency• Inefficient Technology choice- Subcritical units • Older and Smaller plants <300 Mw• High ambient temperature and high humidity – lower

efficiency • Only 1% Super Critical and no Ultra Super Critical • High Outage period• Low PLF• Low O&M• Plants Operating under capacity

Water Pollution from Thermal Power Plants

• Water intensive Industry• Water used for Cooling- discharged at higher temperature- affects

marine/aquatic life• Coal Washing• Ash Dykes• Shop floor washing

• A common cause of thermal pollution is the use of water as acoolant by power plants and industrial manufacturers. ...When water used as a coolant is returned to the naturalenvironment at a higher temperature, the sudden change intemperature decreases oxygen supply and affects ecosystemcomposition. Fish and other organisms adapted to particulartemperature range can be killed by an abrupt change in watertemperature (either a rapid increase or decrease) known as"Thermal shock."

Combating Pollution from Thermal Power Plants

Government Initiatives EC is mandatoryStricter EC conditionsStricter Standards for Air and

Water PollutionCoal Benification NotificationFly Ash Notification

Environment Clearance - Mandatory

• Prior Environment Clearance as per the Environment Impact Assessment (EIA)Notification, 2006 under the Environment (Protection) Act, 1986 has to betaken.

• TPPs are listed at Item 1 (d) of the schedule of the EIA Notification, 2006.

• As per this Notification, Thermal Power Plants (coal/lignite/naphta & gasbased) of capacity ≥ 500 MW have been classified as “A” category projects andrequires environment clearance from the Central Government. Thermal PowerPlants based on Pet coke diesel and all other fuels require environmentclearance from the Central Government for ≥ 50 MW.

• Less than these capacity are classified as “B” category and require environmentclearance from the State Level Environment Impact Assessment Authorities(SEIAA).

• Approvals for new capacities only for supercritical/ultra supercriticalplants

New emission Standards notified on 07.12.2015

Air Emission Norms for Gas Based Thermal Power Plants

Gas/Naptha based Thermal Power Plants

(i) Emission standards for NOx

(a) For units installed before 1-6-1999- 150 ppm (v/v) at 15% excess oxygen

(b) For units after 1-6-1999 - (Limit for NOx emission (v/v), at 15% excess oxygen)

Generation capacity of gasturbine (i) 50 ppm for the units burning natural gas 400 MW and above (ii) 100 ppm for the units burning naphtha

Less than 400 MW but upto 100 MW - (i) 75 ppm for the units burning natural gas (ii) 100 ppm for the units burning naphtha

Less than 100 MW - 100 ppm for units burning natural gas or naphtha as fuel For the plants burning gas in a conventional boiler- 100 ppm

(ii) Stack Height to be calculated by the formula

Conditions in EC for Air Pollution

• Flue Gas Desulphurisation System to be installed basedon Lime/Ammonia dosing to meet the SO2 emissionsstandard of 100 mg/Nm3.

• Selective Catalytic Reduction (SCR) system or theSelective Non-Catalytic Reduction (SNCR) system or LowNOX Burners with Over Fire Air (OFA) system to achieveNOx emission standard of 100 mg/Nm3.

• High efficiency Electrostatic Precipitators (ESPs) to beinstalled in each unit to meet the PM standards of 30mg/Nm3.

• Stacks of prescribed height shall be provided withcontinuous online monitoring instruments for SOx, NOxand Particulate Matter.

• Exit velocity of flue gases shall not be less than 20-25m/s.

• Mercury emissions from stack shall also be monitoredperiodically.

Other Conditions

• Continuous Ambient Air Quality monitoring tobe installed within the plant area at least at onelocation.

• Manual Monitoring at atleast three locationsoutside the plant area.

• Dust extraction/suppression system in coalhandling, ash handling areas and materialtransfer points to control fugitive emissions.

• Appropriate Air Pollution Control measures(DEs/DSs) at all dust generating sources likewater sprinkling arrangements at variouslocations viz. roads, excavation sites, crusherplants, transfer points, loading and unloadingareas, etc.

For Water Pollution

• COC of 5.0 or above for closed cycle with fresh water

• To achieve specific water consumption of 2.5 m3/MWbr.

• Zero Discharge • COC of 1.5 or above for open cycle with

sea water.• Groundwater shall not be drawn during

construction of the project unless permission from CGWA.

For Water Pollution

• In case of the water withdrawal from river, a minimumflow 15% of the average flow of 120 consecutiveleanest days should be maintained for environmentalflow whichever is higher, to be released during thelean season after water withdrawal for proposed powerplant.

• Records for daily water withdrawal and upstreamand downstream river flows to be maintained.

• Rainwater harvesting in and around the plant area betaken up. If possible, recharge of groundwater to beundertaken.

• Atleast six monthly monitoring of groundwaterquality in and around the ash pond area, includingheavy metals (Hg, Cr, As, Pb, etc.) to be carried out . .

For Water Pollution

• Surface water quality monitoring to be undertakenfor major surface water bodies.

• The treated Effluents from different processessuch as DM plant, boiler blow down, ashpond/dyke, sewage, etc. to be treated conformingto the prescribed standards and to be re-circulated and reused.

• Sludge/ rejects to be disposed off in accordancewith the Hazardous Waste Management Rules.

• Hot water dispensed from the condenser should beadequately cooled to ensure the temperature of thereleased surface water is not more than 5degrees Celsius above the temperature of theintake water.

For Water Pollution

• Water to be used from the near by SewageTreatment Plants within the radius of 50 km

• Wastewater from various sources (coolingtower blow down, boiler blow down,wastewater from ash handling etc.) to betreated to meet the standards

• Sewage Treatment plant to be set up forSewage

• Ash pond to be lined Adequate protection fordam/dyke ash dyke from getting breached.

Coal Beneficiation Notification

• First notified in June, 2002. Latest GSR-02 (E) dated 2nd

January, 2014.Coal of Ash content <34% will be used by -• Stand alone TTPs of any capacity or 100 MW and above

captive TTPs located beyond 1000 km from the pit head-with immediate effect

• Stand alone TTPs of any capacity or captive plants of 100 Mw or more located at a distance of 750-1000 km – 1st

January , 2015• 500-749 km – 5th January, 2016 Fluidized Combustion bed , Integrated Gasification

Combined technology exempted Coal Rejects is an issue- costs – Rs. 85-135/tonne and 1.5-2.5

tonne of water /tonne of coal

How to meet the Requirement

• Short Term Measure: Blending of low ash withhigh ash coal at the plant site on annual averagebasis.

• Long Term Measure: Setting up of coal washeriesto meet the requirement -

• The Coal producers sell beneficiated coal• The consumers (TTPs) set up coal beneficiation

units at the mine site.• A third party undertakes coal washing on Build

Own Operate basis for either the producer or theconsumer.

Benefits of Thermal Coal Beneficiation

• Saving in transportation• Saving in capital and operating cost of power plants.• Cost of energy produced using washed coal may also

reduce further provided the washed coal helps inincreasing PLF and washery rejects are utilizedefficiently in higher capacity AFBC/CFBC boilRegulating the quality of coal feed

• Reduce the ash content resulting in improving the lifeof the pressure parts of the boilers, grinding parts ofmill, pulverized coal pipe lines, coal burner nozzles,ducts, ESP internals, air pre-heater seals, ID fanimpellers etc.

• Specific secondary oil consumption is also expected toreduce.

• Less Fly Ash handling cost•

ers.

Expected Environmental Benefits

• Reduction in PM, Sulhur dioxde and Oxide ofNitrogen by about 40, 48 & 48 % respectivelywhich in turn will help in improvement in AAQ inand around thermal power plants.

• Reduction of mercury emission by about 60%

• Limiting the use of water in thermal power plantwill lead to reduction in water consumption byabout 40%. Thermal power plant is one of thewater intense category (70% of total Industrialwater is consumed in Power sector).

Available TechnologiesPollutant Existing approach Future technologies to be adopted

Water Consumption

Once through / coolingtower without recycling

Ash pond effluent recycling sincethe year 2005 onwards

Cooling tower with recycling of effluent with RO systemAsh pond effluent recycling from day one

Particulate matter

Electrostatic precipitator (ESP)with efficiency of 99.6% Use of beneficiated coal

Electrostatic precipitator with efficiency of 99.9% / Hybrid ESP/ bag filterCompulsory use of beneficiated coal

SO2 Dispersion in larger area by providing Tall stack height

Flue gas Desulphurisation with 90% SO2 reduction in emission

NOx Low NOx burners Low NOx burners & two layer of Over fireAir/ Selective Catalytic Reduction/ SelectiveNon Catalytic reduction with 90% efficiency

Mercury No control Will be controlled as co- benefit with SO2 and NOx control technologies

Fly Ash Utilisation For Thermal Power Plants

• The fly ash generation in India has increased from 40 million toneduring 1994 to about 172 million tone (MT) in the 2013-14. Theannual generation of fly ash is expected to be >300 million ton everyyear by 2021-22.

• The main objective of notification for using beneficiated coal is toreduce fly ash generation at power plant site.

• In order to make mandatory use of fly ash and fly ash based productsby the brick kilns, Thermal Power Stations and CPWD & State PWDs, anotification was issued September 14, 1999 by the Ministry ofEnvironment. In 2009, TTPs to use 100% of the fly ash after the4th/5th year of commissioning .

• Presently, only about 50-60 per cent of the 172 million odd tonne offly ash generated by the sector is utilised. The remaining is dumpedinto poorly designed and maintained ash ponds.

Fly Ash Utilisation Notification For Thermal Power Plants

• No person shall within a radius of 100 kms fromthermal power plants, manufacture clay bricks, tilesor blocks without mixing atleast 25% of flyash or pondash with soil.

• Every construction Agency including private sectorbuilders within a radius of one hundred kilometersfrom coal or lignite based thermal power plant shalluse the fly ash based product for construction.

Revised Fly Ash Utilisation Notification

Revised Fly Ash Utilization Notification- S.O.254 (E) dated 25th

January , 2016

• The distance increased from 100 km to 300 km .

• 20% of Dry fly ash to be given free of cost is now removed provided TTP is able to sale it.

• TPPS to install dry SILOS with separate access.

• TPPs to up-load data on stock position of ash availability on their web-site -once in every month.

• TTPs to install ash based manufacturing facilities .

Revised Fly Ash Utilisation Notification

• The cost of transportation of fly ash up to 100 km for such projects to be borne by the concerned TTP.

• The cost of transportation beyond 100 km and up to 300 km to be shared equally between the construction agency and the TTP .

• TTPs will bear entire cost of transportation of fly ash to road constructionprojects under Pradhan Mantri Gramin Sadak Yojna (PMGSY) and assetcreation programmes of the Government.

• The State Authorities approving construction projects to ensure anagreement or MoU between the TTPs and construction agencies.

• State Authorities to amend the by-laws for cities having population of One Million or more .

• Authoritie for Raoad Construction shall pay to the contractor only after getting the certificate of fly ash use certificate from the TPPs

EC Conditions for Fly Ash

• Fly ash to be collected in dry form• Ash to utilised as per provisions of the Notification

on Fly Ash Utilization By the end of 4th year, 100% fly ash utilization to be ensured.

• Unutilized ash to be disposed off in the ash pond in the form of High Concentration Slurry.

• Ash water recycling system shall be set up to recover supernatant water.

• Mercury and other heavy metals (As, Hg, Cr, Pb, etc.) to be monitored in bottom ash and in the effluents from the ash pond.

• Flyash utilization compliance Study to be published on company’s website.

THANK YOU

Sanchita Jindalsansomj@gmail.com#9810865227

Earlier Air Emission Standards For Thermal Power Plants

• So far prevailing Emission Standards for Particulate matter emission were-

• Less than 210 MW - 350 mg/Nm3

• 210 MW or more - 150 mg/Nm3

• APCB and DPCC have stipulated stringent standards of 115 and 50 mg/Nm3 respectively.

• National norms for SOx, NOx and Mercury (Hg) were absent.

• Stack height criteria was only considered for proper dispersion of SO2 emissions.

Earlier Air Emission Standards For Coal / Lignite Based Thermal Power Plants

• Stack height (m) for < 200/210 MW would be calculated by H = 14(Q) 0.3 where Q is emission rate of SO2 in kg/hr, H = Stack height in metre

• For 200/210 MW or <500 MW- 220 m height • 500 MW and above – 275 m • For larger capacities of boilers (500 m and

above)- space provision for installing FGD system was needed to be provided

• Stringent Norms : S.O.3305 (E) dated 7th December, 2015-TO BE MET WITH IN TWO YEARS

TPPs installed before 31st December, 2003- PM – 100 mg/Nm3, SO2 – for unit smaller than 500 Mw- 600 mg/Nm3

- for 550 Mw and above- 200 mg/ Nm3 NOx – 600 mg/Nm3

Tighter Air Emission Standards For Thermal Power Plants

Tighter Air Emission Standards For Thermal Power Plants

TPPs installed after 1st January, 2003 and upto 31st December, 2016- PM – 50 mg/Nm3, SO2 – for unit smaller than 500 MW- 600 mg/Nm3

- for 550 Mw and above- 200 mg/ Nm3 NOx – 300 mg/Nm3 Mercury (Hg) – 0.03mg/Nm3

TPPs installed to be installed from 1st January, 2017 including which have been given EC and are under construction PM – 30 mg/Nm3, SO2- 100 mg/ Nm3 NOx – 100 mg/Nm3 Mercury (Hg) – 0.03mg/Nm3