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FLYASH (SOLID- WASTE) MANAGEMENT AS ONE OF THE PROSPECTS & CHALLENGES OF ELECTRICAL POWER INDUSTRY IN INDIA

INTRODUCTION

 

  1. ENERGY :Nowadays the life of human beings is impossible without energy which in the form of Electricity,Oil,Gas,etc.Electricity is the major form of energy being consumed by people.

Energy is one of the major inputs for the economic development of any country. Energy can be classified into several types based on the the criteria of 1)Primary and Secondary energy  2)Commercial and Non- commercial energy  3)Renewable and Non-Renewable energy.

Primary energy sources are those that are either found or stored in nature. Common pri- mary energy sources are coal, oil, natural gas, and biomass,etc.Primary energy sources are mostly converted in industrial utilities into secondary energy sources; for example coal, oil or gas converted into steam

Commercial Energy: The energy sources that are available in the market for a definite price are known as commercial energy. By far the most important forms of commercial energy are electricity, coal and refined petroleum products. Examples: Electricity, lignite, coal, oil, natural gas etc.Non-Commercial Energy: The energy sources that are not available in the commercial market for a price are classified as non-commercial energy. Non-commercial energy sources include fuels such as firewood, cattle dung and agricultural wastes, which are traditionally gathered, and not bought at a price used especially in rural households.

Renewable energy is energy obtained from sources that are essentially inexhaustible. Examples of renewable resources include wind power, solar power, geothermal energy, tidal power and hydroelectric power.Non-renewable energy is the conventional fossil fuels such as coal, oil and gas, which are likely to deplete with time.

The per capita Electricity consumption in India as of March,2013 is 917.2 kWh against the world average of 2782 kWh.India placed in 51st place in electricity consumption among the world,. In India Goa tops with 2264, Delhi with 1651,Gujarat with 1615 and at the bottom Bihar with 122 kWh. All it reveal that there is lot more scope for increase in the per capita electricity consumption in India in future.

2) POWER PLANTS :In India at the time of Independence,1947, power generation capacity of the Power plants was just 1362 MW only. By September,2014, the installed capacity of Power Plants of Utility is 2,54,049 MW and additionally 39,375 MW of captive plants are existing, i.e., total of 2,93,424 MW. Non Renewable Power Plants constitute 87.55 % and that of Renewable 12.45 %.

Growth of Installed Capacity in India

 
Installed Capacity
as on
Thermal (MW) Nuclear
(MW)
Renewable (MW) Total (MW) % Growth
(on yearly basis)
 
Coal Gas Diesel Sub-Total
Thermal
Hydel Other
Renewable
Sub-Total
Renewable
 
31-Dec-1947 756 98 854 508 508 1,362  
31-Dec-1950 1,004 149 1,153 560 560 1,713 8.59%  
31-Mar-1956 1,597 228 1,825 1,061 1,061 2,886 13.04%  
31-Mar-1961 2,436 300 2,736 1,917 1,917 4,653 12.25%  
31-Mar-1966 4,417 137 352 4,903 4,124 4,124 9,027 18.80%  
31-Mar-1974 8,652 165 241 9,058 640 6,966 6,966 16,664 10.58%  
31-Mar-1979 14,875 168 164 15,207 640 10,833 10,833

26,680

12.02%  
31-Mar-1985 26,311 542 177 27,030 1,095 14,460 14,460 42,585 9.94%  
31-Mar-1990 41,236 2,343 165 43,764 1,565 18,307 18,307 63,636 9.89%  
31-Mar-1997 54,154 6,562 294 61,010 2,225 21,658 902 22,560 85,795 4.94%  
31-Mar-2002 62,131 11,163 1,135 74,429 2,720 26,269 1,628 27,897 105,046 4.49%  
31-Mar-2007 71,121 13,692 1,202 86,015 3,900 34,654 7,760 42,414 132,329 5.19%  
31-Mar-2012 112,022 18,381 1,200 131,603 4,780 38,990 24,503 63,493 199,877 9.00%  
30-June-2014 148,478 22,608 1,200 172,286 4,780 40,730 @31,692 72,422 249,488

10.35%

 

 

Growth of Electricity Consumption in India  
Consumption
as on
Total (in GWh) % of Total Per-Capita
Consumption
 (in kWh)
 
Domestic Commercial Industrial Traction Agriculture Misc  
31-Dec-1947 4,182 10.11% 4.26% 70.78% 6.62% 2.99% 5.24% 16.3  
31-Dec-1950 5,610 9.36% 5.51% 72.32% 5.49% 2.89% 4.44% 18.2  
31-Mar-1956 10,150 9.20% 5.38% 74.03% 3.99% 3.11% 4.29% 30.9  
31-Mar-1961 16,804 8.88% 5.05% 74.67% 2.70% 4.96% 3.75% 45.9  
31-Mar-1966 30,455 7.73% 5.42% 74.19% 3.47% 6.21% 2.97% 73.9  
31-Mar-1974 55,557 8.36% 5.38% 68.02% 2.76% 11.36% 4.13% 126.2  
31-Mar-1979 84,005 9.02% 5.15% 64.81% 2.60% 14.32% 4.10% 171.6  
31-Mar-1985 124,569 12.45% 5.57% 59.02% 2.31% 16.83% 3.83% 228.7  
31-Mar-1990 195,098 15.16% 4.89% 51.45% 2.09% 22.58% 3.83% 329.2  
31-Mar-1997 315,294 17.53% 5.56% 44.17% 2.09% 26.65% 4.01% 464.6  
31-Mar-2002 374,670 21.27% 6.44% 42.57% 2.16% 21.80% 5.75% 671.9  
31-Mar-2007 525,672 21.12% 7.65% 45.89% 2.05% 18.84% 4.45% 559.2  
31-March-2012 785,194 22.00% 8.00% 45.00% 2.00% 18.00% 5.00% 883.6  
31-March-2013 852,902 21.79% 8.33% 44.87% 1.81% 17.95% 5.25% 917.2

In FY 2012-13, the total power generation was 967 TWh by Utility and 135.75 TWh by captive and renewable plants ( ,i.e.,total :1102.90 TWh) emerged as third highest power producer  with 4.8% of global share,surpassed  Japan and Russia . The 60% of the total capacity  is of thermal power. The 57% of total installed capacity is from Coal-based thermal power plants, i.e., 1,20,103 MW, and many new projects are in pipeline. The SEBs, NTPC,DVC, NHPC,NPCL,PGCI and many more corporates contributing for power industry.

Our country is facing power shortage normal and  peak demand to the tune of 10.9% and 13.8%  respectively.High transmission &distribution losses prevailing. The AT&C(Aggregate Technical & Commercial) losses to 26% against the world average of 9%. In J&K Orissa,UP,Bihar, Jharkhand and North Eastern States the losses are more than 40%.

The 12th Five Year Plan (April 2012 to March2017),projections made by Planning Commission indicate that for a sustained Gross Domestic Product(GDP) growth rate of 9% per yaer,energy supply has to grow at around 6.5% per year.As per IEA projections,per capita energy consumption in India will be 1895 kWh by year 2030. Hence installed capacity should be more than 5,00,000 MW along with associated T&D network.In order to achieve the projected capacity addition of around 1,00,000 MW and commensurate T&D capacity,investment of more than INR 11,00,000 crore would be required in 12th Five Year Plan.Moreover,for proper functioning of the power system, investments in Generation Vs Transmission Vs Distribution should be in the ratio of 2:1:2.

3) COAL :Coal is the most abundantly available fossil fuel having world reserves of 826 billion tons which will be sufficient for about 114 years.USA(29%), Russia(19%),China(14%),Australia(9%) and India(7%) of world reserves existing,i.e., India occupies 5th place (58.6 Billion Tons) in coal reserves and 3rd place in coal production. In India 80% of coal consumed by Power sector. It is high ash content (30—45%) with low CV (3000—4500 kCal/kg) coal which being mined about 80% in open- cast and 20% as under-ground.

4) FLYASH : The residual solid waste that comes from coal burning is Flyash which is a major concern of coal based thermal Powerplants. As our ENERGY consumption going to be increased, many more coal-based thermal POWER PLANTS about to come and the COAL consumption expected to increase drastically in future.It is the big concern for disposal since the quantity generated is very very huge because Indian coal contains high percentage of ash in the range of 30 to 45%. Even it would be very high in case of coal –washerymiddlings  which especially used in AFBC and CFBC boilers, generally those designed for inferior quality coal.

The Flyash could be marketed as a by-product but the fields of utilization have been not favourable. In addition to it,theGovt.authorities not being insisting the parties strictly to use the flyash mix in various products, e.g., Flyashbricks,FlyashProducts,CementProduction,LandFilling,Embankments,etc. Govt of India (MoEF) enacted the ‘Flyash notification’ in year 1999 and amended in 2003 and 2009 and stressing upon the industries to implement the flyash utilization. But however the statutory support for the utilization by others is not appreciable.Flyash is the solid waste from coal-based thermal power plants. The Flyash could be marketed as a by-product but the fields of utilization have been not favourable. In addition to it,theGovt.authorities not being insisting the parties strictly to use the flyash mix in various products, e.g.Flyasbricks,Flyash Products,Cement Production,Land Filling,Embankments,etc. Govt of India (MoEF) enacted the ‘Flyash notification’ in year 1999 and amended in 2003 and 2009 and stressing upon the industries to implement the flyash utilization. But however the statutory support for the utilization by others is not appreciable.

5) CLASSIFICATION OF FLYASH:

Fly ash particles are generally spherical in shape and range in size from 0.5 μm to 100 μm. They consist mostly of silicon dioxide (SiO2), which is present in two forms: amorphous, which is rounded and smooth, and  rystalline, which is sharp, pointed and hazardous; aluminum oxide (Al2O3) and iron oxide (Fe2O3). Fly ashes are generally highly heterogeneous, consisting of a mixture of glassy particles with various identifiable crystalline phases such as quartz, mullite, and various iron oxides. Two classes of fly ash are defined by ASTM C618: Class F fly ash and Class C fly ash.

The chief difference between these classes is the amount of calcium, silica, alumina, and iron content in the ash. The chemical properties of the fly ash are largely influenced by the chemical content of the coal burned (i.e., anthracite, bituminous, and lignite)

The American Society for Testing and Materials, ASTM C-618,  defines pozzolan as “a siliceous or siliceous and aluminous material, which in itself possesses little or no cementitious value, but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures (> 40°F (> 5C),to form compounds possessing cementitious properties.”Natural pozzolans and fly ashes categorized into the following three ( C,F and N)

Class- C  fly ash normally comes from coals which may produce an ash with higher lime content — generally 15 to 30 percent. Elevated CaO may give Class C unique self-hardening characteristics.

Class- F fly ash is available in the largest quantities. Class F is generally low in lime, usually under 15 percent, and contains a greater combination of silica, alumina and iron (greater than 70 percent)

Class N   Raw or calcined natural pozzolans such as some diatomaceous earths, opalinechert and shale, stuffs, volcanic ashes and pumice come in this category. Calcined kaolin clay and laterite shale also fall in this category.

Class F and Class C fly ash are products of the combustion of coal in power plants. Although both types of fly ash impart a wide range of qualities to many typesof concrete, they differ chiefly in the following ways:

Class F –Most effectively moderates heat gain during concrete curing and istherefore considered an ideal cementitious material in mass concreteand high strength mixes. For the same reason, Class F is the solution to a wide range of summer concreting problems.  Provides sulfide and sulfate resistance equal or superior to Type V cement. Class F is often recommended for use where concrete may be exposed to sulfate ions in soil and ground water.

Class C-  Most useful in “performance” mixes, prestressed applications, and other situations where higher early strengths are important.  Especially useful in soil stabilization since Class C may not require the addition of lime.

  • FLYASH NOTIFICATION

Flyashis categorised as high volume low effect waste under Hazardous Wastes ( Management, Handling & Trans boundary movement ) Rules ,2008. Chemically ,flyash mainly consists of oxides of silica, aluminium, Iron and calcium., besides trace of elements like arsenic, beryllium, boron,cadmium, chromium, chromium VI, cobalt, lead, manganese, mercury, molybdenum etc.

Environmental issues

  • Air Pollution ( Dust emission from ash pond)
  • Water Pollution ( Contamination of ground &
  • surface water
  • Land degradation

Govt of India , Ministry of Environment & Forests (MoEF) issued Notification for Flyash  on Dt.14th Sept., 1999 vide SO 763(E) ,First Amendment vide . S.O.979(E), [27/8/2003] and Second amendment vide S.O. 2804(E), [ 03.11.2009]

Objectives

  • To protect the environment, conserve top soil and prevent the dumping and disposal of fly ash from coal or lignite based thermal power plants

Directions /Notification

  • Use of flyash, bottom ash or pond ash in the manufacture of Building Materials /Products
  • Use of Flyash in civil construction jobs
  • Specifications for use of flyash based products by Government agencies
  • Backfilling of Mines

Second Amendment

2.S.O. 2804(E), [ 03.11.2009]- Amendments to  S.O. 763 (E) dated 14/09/1999

[ Flyash means and includes ash collected from ESP, dry flyash, bottom ash, pond ash & mound ash generated from coal/lignite based thermal power plants including CPP]

Amendment dated 3rd November 2009

“(1A)     Every construction agency engaged in the construction of buildings within a radius of hundred kilometers (by road) from a coal or lignite based thermal power plant shall use only fly ash based products for construction, such as:

cement/concrete, fly ash bricks or blocks or tiles or clay fly ash bricks, blocks or tiles or cement fly ash bricks or bricks or blocks or similar products or a combination or aggregate of them in every construction project.

(1B)      Applicable to all construction agencies of Central or State or Local Government and private or public sector. Submit annual returns to the concerned State Pollution Control Board or Pollution Control Committee.”;

(1C)       Minimum Flyash content for building materials or products to qualify as ‘ flyash based Products’

SNo Building Materials or Products Minimum % of Flyash by Weight
01 Flyash bricks, Blocks, Tiles,etc made with Flyash, lime, Gypsum,S and, Stone Dust, Cement,etc (without Clay) 50% of Total raw material
02 Paving Blocks,Tiles,Chequeredtiles,mosaictiles,RoofingSheets,Precastelements,etc (where in cement used as binder) Uasage of PPc(flyash) or 20% of OPC content
03 Cement 20% of raw materials
04 Clay based building-materials 25% of raw materials
05 Concrete,mortar and plaster Usage of PPC(flyash) or 20% of total raw materials

 

“(2A) State Government or Union territory Government shall be the enforcing and monitoring authority for ensuring compliance of the provisions of sub-paragraph (1A) and (1B).”;

  1. “(4) Each coal or lignite based thermal power plant shall constitute a dispute settlement committee
    Composition:
    General Manager of the thermal power plant
    Representative of the relevant Construction and fly ash Brick Manufacturing Industry Association / Body
    TOR
    Ensure unhindered loading and transport of fly ash without any undue loss of time.( 5) Construction of Flyover embankments
    Approval of design & Construction of roads or flyover embankments with top soil shall not be permitted by any agency, person or organization within a distance of one hundred kilometers (by road) of a thermal power plant
    • The guidelines or specifications issued by the Indian Road Congress (IRC) as contained in IRC specification No. SP: 58 of 2001 regarding use of fly ash shall be followed.
    • Any deviation from this direction can only be agreed to on technical reasons approved by Chief Engineer (Design)/ Engineer-in-Chief of the concerned agency or on production of a certificate of “fly ash not available” from the thermal power plant(s) (TPPs) located within hundred kilometers of the site of construction.

Reclamation and compaction of low-lying areas No agency, person or organisation shall within a radius of hundred kilometers (by road) of a coal or lignite based thermal power plant undertake or approve or allow reclamation and compaction of lowlying areas with soil. Only fly ash shall be used for compaction and  reclamation. They shall also ensure that such reclamation and compaction is done in accordance with the specifications and guidelines laid down

  • Stowing of mine :No person or agency shall within fifty kilometers (by road) from coal or lignite based thermal power plants, undertake or approve stowing of mine without using at least 25% of fly ash on weight to weight basis, of the total stowing materials used and this shall be done under the guidance of the DGMS or CMPDIL
  • Back Filling of open cast mines :No person or agency shall within fifty kilometers (by road) from coal or lignite based thermal power plants, undertake or approve without using at least 20% of fly ash on volume to volume basis of the total materials used for external dump of overburden and same percentage in upper benches of back filling of opencast mines and this shall be done under the guidance of DGMS or CMPDIL

Sale of flyash :All coal or lignite based thermal power stations would be free to sell fly ash to the user agencies subject to the following conditions:

  • The pond ash and mound ash should be made available free of any charge on “as is where is “basis to manufacturers of bricks, blocks or tiles including clay fly ash product manufacturing unit(s), farmers, the

Central and the State road construction agencies, Public Works Department, and to agencies engaged in backfilling or stowing of mines.

  • At least 20% of dry ESP fly ash shall be made available free of charge to units manufacturing fly ash or clay-fly ash bricks, blocks and tiles on a priority basis over other users. If the demand from such agencies falls short of 20% of quantity, the balance quantity can be sold or disposed of by the power station. Provided that the fly ash obtained from the thermal power station should be utilized only for the purpose for which it was obtained failing which no fly ash shall be made available to the defaulting users.m

All coal and, or lignite based Thermal Power Stations and, or expansion units in operation before the date of this notification are to achieve the target of fly ash utilization as per the table •

SNo Percentage Utilizatio of Flyash Target date
1 At least  50%   of Flyash generation One year from the date issue of Notification
2 At least  60%   of Flyash generation Two years from the date issue of Notification
3 At least  70%   of Flyash generation Three years from the date issue of Notification
4 At least  90%   of Flyash generation Four yearsfrom the date issue of Notification
5 At least  100%  of Flyash generation Five years from the date issue of Notification

The unutilized fly ash in relation to the target during a year, if any, shall be utilized within next two years in addition to the targets stipulated for those years. The balance unutilized fly ash accumulated during first four years (the difference between the generation and the utilization target) shall be utilized progressively over next five years in addition to 100% utilization of current generation of fly ash

New coal and, or lignite based Thermal Power Stations and, or expansion units commissioned after this notification to achieve the target of fly ash utilization as per table •

SNo Percentage Utilizatio of Flyash Target date
1 At least  50%   of Flyash generation One year from the date of Commissioning of the Plant
2 At least  70%   of Flyash generation Two years from the date of Commissioning of the Plant
3 At least  90%   of Flyash generation Three years from the date of Commissioning of the Plant
4 At least  100%  of Flyash generation Four years from the date of Commissioning of the Plant

The unutilized fly ash in relation to the target during a year, if any, shall be utilized within next two years in addition to the targets stipulated for these years. The unutilized fly ash accumulated during first three years (the difference between the generation and utilization target) shall be utilized progressively over next five years in addition to 100% utilization of current generation of fly ash.”;

Land for ash disposal for future plants

The Central Electricity Authority and other approving agencies may permit the land area for emergency ash pond or fly ash storage area up to 50 hectares for a 500 MW unit, based on 45% ash content coal, or in the same proportion for units in other capacities taking into account the ash content in coal or lignite to be used.

Annual Implementation Report

  • Annual implementation report (for the period 1st April to 31st March) providing information about the compliance of provisions in this notification shall be submitted by the 30th day of April, every year to the Central Pollution Control Board, concerned State Pollution Control Board or Committee and the concerned Regional Office of the Ministry of Environment and Forests by the coal or lignite based thermal power plants, and also be made a part of the annual report of the thermal power plant as well as thermal power plant wise information be provided in the annual report of thermal power producing agency owning more than one thermal power plant.”;

Directions to all agencies undertaking construction of roads or fly over bridges and reclamation and compaction of low lying areas, including Department of Road Transport and Highways (DORTH), National Highways Authority of India (NHAI), Central Public Works Department (CPWD), State Public Works Departments and other State Government Agencies,

  1. make provisions in their tender documents, schedules of approved materials and rates as well as technical documents for implementation of this notification, including those relating to soil borrow area or pit
  2. make necessary specifications or guidelines for road or fly over embankments that are not covered by the specifications laid down by the Indian Road Congress (IRC).
  • All local authorities shall specify in their respective tender documents, building bye-laws and regulations, the use of fly ash and fly ash-based products and construction techniques in building materials, roads embankments or for any usage with immediate effect
  • CHALLENGES IN COAL -FLYASH  MANAGEMENT

Coal fly ash is an industrial waste generated from coal combustion process in thermal power plants. It is a fly ash, a coal combustionresidue having a complex heterogeneous mixture of amorphous andcrystalline phases and is generally fine powderedferroaluminosilicate material with Al, Ca, Mg, Fe, Na and Si as the

predominant elements. The coal fly ash also contains significantamounts of toxic metals such as As, Ba, Hg, Cr, Ni, V, Pb, Zn and Secharacteristically enriched in coal fly ash particles

Fly ash emissions from a variety of coal combustion units show a wide range of composition. All elements below atomic number 92 are present in coal ash. A 500 MW thermal power plant releases 200 mt SO2, 70 t NO2 and 500 t fly ash approximately every day. Particulate matter (PM) considered as a source of air pollution constitutes fly ash.

Coal ash creates multiple problems. this can gravely pollute air and water sources, with severe health impact. This is a serious issue as ash has several toxic elements including heavy metals and also suspected radioactivity.It is a very fine material about 60-70% of which is below 76 microns.Principal contents of flyash are normally Silica(30-60%),Alumina(15-30%),Iron Oxides(10-15%), and small quantities of CaO, MgO , Sulphates,etc.

Ash disposal

Coal ash is disposed off in two ways. One is through dry disposal, wherein ash is deposited in ash Mounds. The second is wet disposal, where ash is mixed with water to make slurry which is disposed of in ash ponds/ dykes. Both methods are causing several risks, including ash being blown by winds onto habitations, farms and water bodies, and contamination of water sources through leaching, spilling and ash dyke breaches (not to mention illegal discharge of ash into streams, rivulets and rivers). Moreover huge quantities of water and large areas of land are required for such disposal of ash.However, there is another way to handle ash. Ash can also be re-used and utilised in several applications.

FLYASH Generation and Utilization (Source: CEA Annual Report 2013-14)

SNo Year Flyash Generation

(Million Tons)

FlyashUtilisation

(Million Tons)

% Utilisation
1 1996-97 68.88 6.64 9.63
2 1997-98 78.06 8.43 10.80
3 1998-99 78.99 9.22 11.68
4 1999-00 74.03 8.91 12.03
5 2000-01 86.29 13.54 15.70
6 2001-02 82.81 15.57 18.80
7 2002-03 91.65 20.79 22.68
8 2003-04 96.28 28.29 29.39
9 2004-05 98.57 37.49 38.04
10 2005-06 98.97 45.22 45.69
11 2006-07 108.15 55.01 50.86
12 2007-08 116.94 61.98 53.00
13 2008-09 116.69 66.64 57.11
14 2009-10 123.54 77.33 62.6
15 2010-11 131.09 73.13 55.79
16 2011-12 145 85.05 58.48
17 2012-13 163.56 100.37 61.37
18 2013-14 55.62

In the year 2012-13, the total ash generated by thermal power plants in the country was 163.56 million tons.  To put this in perspective, the entire municipal solid waste generated in the country in 2012 was 127,486 tons per day, or 46.5 million tons per year. This is just about 32 per cent of the coal ash generated in the country in the year 2011-12.

PERCENTAGE FLY ASH UTILIZATION DURING THE 1 st HALF OF THE YEAR 2013-14 (CEA Report)

SNo. Level of FlyashUtilisation No. of Power Stations
1 100% and more than 100% 39
2 Less than 100% and up to 75% 29
3 Less than 75% and up to 60% 17
4 Less than 60% 52
Nos. of TPS which have not generated any significant fly ash or any 04
141

FLYASH Utilization Sector- wise (CEA Annual Reports 2011-12)

SNo Sector Utilisation(Million Ton)

FY:2011-12

Utilisation(Million Ton)

FY:2012-13

1 Cement 38.08 41.33
2 Reclamation of Low-Lying Area 14.21 11.83
3 Roads & Embankments 5.54 6.02
Concrete 0.63 1.03
Ashdyke Raising 5.86 10.93
4 Mine Filling 7.74 10.34
5 Bricks& tiles 5.83 9.98
6 Agriculture 0.88 2.5
7 Others 6.28 6.41
T O T A L 85.05 100.37

FLYASH Utilization Sector- wise (CEA Annual Report 2011-12)

SNo Sector % Utilisation
1 Cement 48.13
2 Reclamation of Low-Lying Area 8.72
3 Roads & Embankments 13.02
4 Mine Filling 6.76
5 Bricks& tiles 6.51
6 Agriculture 1.02
7 Others 15.83

FLYASH Utilization Sector- wise During the 1st half of the Year 2013-14 (CEA Annual Report)

SNo Sector % Utilisation
1 Cement 41.53
2 Reclamation of Low-Lying Area ents 11.04
3 Mine Filling 11.40
4 Bricks& tiles 10.68
5 Ashdyke Raising 9.07
6 Roads & Flyover 4.67
7 Agriculture 3.12
Concrete 1.44
Others 7.05

 

Apart from Cement Industry, some of the other uses do little to address the risk of contamination from toxic elements present in fly ash, and for this reason, have been disallowed by the Expert Advisory  Committee (Thermal Power &Coal Minining)  — the EAC — of the Ministry of Environment and Forests (MoEF). The EAC is the expert body that examines all thermal power projects from the angle of environmental impact and recommends whether to grant them environmental clearance or not, and under what conditions.

In its 12th Meeting, held on 6 Dec 2010, the EAC noted:

Regarding use of Fly Ash in agriculture, the Committee also expressed its strong reservations considering that the available information is limited and not supported by long term scientific study. Considering that flyash is reported to contain about 48 elements including radioactive elements and toxic heavy metals (in mild dose), the Committee advocated that unless scientific study rules out long term adverse health impacts, as such, this method of fly ash disposal shall not be resorted to.

Another worrying “utilisation” is “reclamation of low lying areas”. This is often an euphemism for dumping of ash anywhere. Just as in utilisation modes such as agriculture and filling of mine voids, this too leaves ample scope for the toxic elements to leach out into water sources, or even spread through the wind.

In its 32nd Meeting held on 12 September 2011, the EAC noted that:

It was pointed out that over a period of time due to weathering action heavy metals or radioactivity content increases manifold when fly ash is left open in fields. It was, therefore, of paramount importance that a detailed study…be carried out before advocating promotion of fly ash for utilisation in agriculture, reclamation of low lying areas [or] as mine void filling”.

One of the major risk factors identified in coal ash is the presence of radioactivity. While use of ash in manufacture of cement or fly-ash bricks may “fix” or “bind” the ash, so that toxic elements can’t leach out, such products will still remain prone to the risks of radioactivity.

On 20 September 2011, the National Green Tribunal passed an order in a matter related to the Koradi thermal power plant near Nagpur. In this order, the Tribunal ruled that:

Ministry of Environment and Forests is directed to look into the matter as to long term impacts caused by nuclear radiation from the thermal power projects, by instituting a scientific long term study … with reference to the coal ash generated by thermal power project…

CEA then calls upon the MoEF to review these conditions. It’s pertinent to note that the EAC itself has asserted against the use of such technicality by noting, in its meeting in September 2013, that a project has been “carrying out mine void filling activity which is undesirable irrespective of existing legislation permitting mine void filling.” (emphasis added)

Need for comprehensive re-look

While the EAC has been increasingly stressing the risks inherent in any use of ash, and has been suggesting studies and attaching conditions for such use, its approach is still piecemeal and targeted towards individual projects. Further, the EAC only has an advisory role and the final decision is the MoEF’s.

The MoEF, in it’s gazette amendment in 2009, stated to back-fill the mines which located within  in the 50km radius from power stations. Mines authority not accepting the ash to fill since High Stripping Ratio , Swelling Factor of OB,etc

The problem is connected with the  MoEF,Mo Power, Mo Coal Mines, Civil Administartion,etc

  • FLYASHUTILISATION / MANAGEMENT
  1. Development of Fly Ash Based Polymer Composites as Wood Substitute

Fly ash based composites have been developed using fly ash as filler and jute cloth as reinforcement. The technology on fly ash Polymer Composite using Jute cloth as reinforcement for wood substitute material can be applied in many applications like door shutters, partition panels, flooring tiles, wall panelling, ceiling, etc.This technology has been developed by Regional Research Laboratory, Bhopal in collaboration with Building Materials & Technology Promotion Council (BMTPC) and TIFAC. One commercial plant has also been set up based on this technology near Chennai

  1. Fly Ash Based Cement

As per the specifications of Bureau of Indian Standards flyashupto 35% can be used in manufacture of PPC, while worldwide there are examples of countries that permit upto 55% utilisation of fly ash in PPC production. Setting aside 25% of cement production for OPC for such applications, the balance 75% can be PPC with an

average fly ash content of 30% [14]. It would consume around 25 MT fly ash, replacing same amount of cement clinker and resulting in net saving Rs. 2500 crore

  1. Role of bio-amelioration of FA on soil

Recent investigations suggest that FA can find better application if combined with organic amendments such as cow manure,press mud, paper factory sludge, farmyard manure, sewage sludge,crop residues and organic compost for improvement of degraded/marginal soil . Few beneficial combined effects of FA and organic matter on soil have been found such as reduced heavymetal availability and killing pathogens in the sludge ; improved soils through higher nutrient concentrations,bettertexture,lower bulk.density, higher porosity and mass moisture content and higher content of fine-grained minerals enhanced the biological activity

in the soil reduced the leaching of major nutrients ; and beneficial for vegetation; .Use of swine manure with FA increased the availability of Ca and Mg balancing the ratio between monovalent and bivalent cations (Na++ K+/Ca2+ Mg2+), which otherwise proves detrimental to the soil ; Co-utilization of ‘slash’ a mixture of FA, sewage sludge and lime in the ratio of 60:30:10 had beneficial soil ameliorating effect. ‘Slash’ incorporation in soil showed positive effects on soil pH and Ca, Mg and P content and reduction in the ranslocation of Ni and Cd] and enhanced growth and yield of corn, potatoes and beans in pot trials. So, amendment with FA will enhance agricultural sector for crop production. Further, organic amendment application will provided anchorage and growth of the plant on a FA dumping site

  1. Fly ash bricks

The Central Fuel Research Institute, Dhanbad has developed a technology for the utilization of fly ash for the manufacture of building bricks . Fly Ash can be used in the range of 40-70%.Our current clay brick production exceeds 100 billion bricks a year. In such circumstances and when fly ash brick is technically acceptable, economically viable and environment friendly, it may not be wrong to target to produce at least 2 billion fly ash bricks per year. It would  consume about 5 million tonne of flyash/year, yielding a net saving of around Rs. 20 crores per annum. Fly ash bricks have a number of advantages over the conventional burnt clay bricks. Unglazed tiles for use on footpaths can also be made from it. Awareness among the public is required and the Government has to provide special incentives for this purpose .

  1. Fly ash in distemper

Distemper manufactured with fly ash as a replacement for white cement has been used in several buildings in Neyveli, Tamil Nadu, in the interior surfaces and the performance is satisfactory. The cost of production will only be 50% that of commercial distemper.

  1. Fly ash-based ceramics

The National Metallurgical Laboratory, Jamshedpur has developed a process to produce ceramics from fly ash having superior resistance to abrasion.

  1. Ready mixed Fly ash concrete

Though Ready Mix concrete is quite popular in developed countries but in India it consumes less than 5 percent of total cement consumption. Only recently its application has started growing at a fast rate. On an average 20% Fly ash (of cementitious material) in the country is being used which can easily go very high. In ready mix

concrete various ingredients and quality parameters are strictly maintained/controlled which is not possible in the concrete produced at site and hence it can accommodate still higher quantity of fly ash.

  1. Minefills

Nearly one third of our thermal power stations are at or near to pit heads. Most of these mines cart sand for backfilling from river beds, which are normally 50-80 kms away. Apart from the royalty, huge amount of expenditure is incurred on transportation of sand. It is estimated that about 15-20 million tonne of ash per annum can be safely consumed in minefills yielding a saving of about Rs. 150 crore a year

  1. Fly Ash in Road Construction

Fly ash can be used for construction of road and embankment. Saves top soil which otherwise is conventionally used, avoids creation of low lying areas (by excavation of soil to be used for construction of embankments) . Fly Ash may be used in road construction for: Stabilizing and constructing sub-base or base; upper layers of pavements; filling purposes. Concrete with Fly Ash (10-20% by wt) is cost effective and improves performance of rigid pavement;Soil mixed with Fly Ash and lime increases California Bearing Ratio (CBR), increased (84.6%) on addition of only Fly Ash to soil. National Highway Authority of India (NHAI) is currently using 60 lakh m3 of Fly Ash and proposed to use another 67 lakh m3 in future projects.

  1. Embankment

Fly ash properties are somewhat unique as an engineeringmaterial. Unlike typical soils used for embankment construction, flyash has a large uniformity coefficient consisting of clay-sizedparticles. Engineering properties that will affect fly ash use inembankments include grain size distribution, compactioncharacteristics, shear strength, compressibility, permeability, andfrost susceptibility.Nearly all fly ash used in embankments are Class F fly ashesIn view of the growing need for development of roadinfrastructure in the country, conservative estimates show that about15-20 MT ash can be used in construction of road and flyoverembankments per annum in the vicinity of TPPs. This would yield asaving of around Rs. 100 crore per year [

 

  1. Roller compacted concrete

Another application of using fly ash is in roller compacted concrete dams. Many dams in the US have been constructed with high fly ash contents. Fly ash lowers the heat of hydration allowing thicker placements to occur. Data for these can be found at the US Bureau of Reclamation. This has also been demonstrated in the

Ghatghar Dam Project in India

  1. Asphalt concrete

Asphalt concrete is a composite material consisting of an asphalt binder and mineral aggregate. Both Class F and Class C fly ash can typically be used as a mineral filler to fill the voids and provide contact points between larger aggregate particles in asphalt concrete mixes. This application is used in conjunction or as a replacement for, other binders (such as Portland cement or hydrated lime) . For use in asphalt pavement, the fly ash must meet mineral filler specifications outlined in ASTM D242. The hydrophobic nature of fly ash gives pavements better resistance to stripping. Fly ash has also been shown to increase the stiffness of the asphalt matrix, improving rutting resistance and increasing mix durability

  1. Use of Fly Ash in Agriculture

Agriculture and waste land management have emerged as prime bulk utilization areas for fly ash in the country. It improves permeability status of soil; improves fertility status of soil (soil health)/ crop yield; improves soil texture; reduces bulk density of soil; improves water holding capacity/porosity; optimizes pH value;improves soil aeration; reduces crust formation provides micro nutrients like Fe, Zn, Cu, Mo, B, Mn; provides macro nutrients like K, P, Ca, Mg, S etc; works as a part substitute of gypsum for reclamation of saline alkali soil and lime For reclamation of acidic soils; ash ponds provides suitable conditions and essential nutrients.for plant growth, helps improve the economic condition of local inhabitants; crops grown on fly ash amended soil are safe for human consumption & groundwater quality is not affected.Use of fly ash in agriculture has also proved to be economically rewarding. The improvement in yield has been recorded with fly ash doses varying from 20 tonne/hectare to 100 tonne/hectare. On an average 20-30% yield increase has been observed Out of 150 million hectare of land under cultivation, 10 million hectares of land can safely be taken up for application of fly

ash per year. Taking a moderate fly ash dose of 20 mt per hectare it would consume 200 million tonneflyash per year. This is more thanthe annual availability of fly ash, therefore the shortfalls would be metfrom accumulated 1500 million tonne stock of fly ash (available inash ponds). The fly ash treated fields would give additional yield of 5million tonnefoodgrains per year valued at about Rs. 3000 crore.

  • STRATEGIES AND PRACTICES ADOPTED BY J.S.P.L,RAIGARH FOR FLYASH UTILISATION

JINDAL Steel & Power Ltd., Raigarh having CPP with WHRB-18 Nos and Coal fired Boilers 05 No.s The flyash generated from the Boilers have been utilized and also disposed into Ashdykes by using High Concentration Slurry Disposal (HCSD) System. The  flyash generated from the coal fired boilers has been utilized as per the terms of Consent to Operate (CTO) by Chhattiisgarh Environment Conservation Board.

JSPL has adopted all the possible ways of Flyash utilization as followed

  1. Cement Plant-JSPL
  2. Flyash Brick Making Plants (JSPL & Others)
  3. Land Filling ( JSPL & Others)
  4. Mines Back-Filling (JOCCM)
  5. Others
  6. Cement Plant-JSPL

JSPL Cement Plant which is located in adjacent to the steel plant. The slag based cement plant at present running. 2 MTPA integrated cement plant yet to come up. Some quantity of  flyash has been supplied to Cement plant. As the expansion takes place there will be very will be lot scope for flyashutilization.At present no other cement plant is using the flyash from JSPL.

  1. Flyash Brick Making Plants

Earlier JSPL was running Flyash Brick Making Plants at Chiraipani,Khairpur and Cement Plant locations.But the state of the art and India’s biggest automatic Flyash brick making plant installed inside the premises of JSPL-Cement Plant with a capacity of 3,00,000 Bricks/Day. FRIMA Flyash Brick Plant supplied by Germany which had installed and commissioned from July, 2012. This plant has been manufacturing flyash based Bricks, Tiles, etc with good quality and finish by using flyash and bed-ash.

Some of the Flyash Brick Baking Plants   (FBMP) which take the Flyash from JSPL Raigarh as followed.

  1. Flyash Brick Baking Plants (FBMP)
  2. Chattisgarh Cement Products,Chiraipali
  3. Durgaflyash ,Jorapalli
  4. Sri Sai Ash Bricks,Sarangarh
  5. BhumikaFlyash ,Raiagarh
  6. JK FlyashProducts,Sarangarh
  7. MangalFlyashBricks,Kharsia
  8. Land Filling (Low Lying Areas)
  9. We have ash dyke 1 & 2 situated nearby Godamdiba hamlet. We have been using the ash dykes since year 2000 as alternatively. During the tenure we have raised the height of ash dykes couple of times. And we are not intended to further raise the height of ash dykes. Hence in order may use of the dykes for further course of time decided to evacuate the dyke which is inactive. We have made inactive the ash dyke from April 2013.
  10. We have got many requests from the nearby sites for filling the land by fly ash but due to various reasons it was not made thorough. But with the help of top management we have taken inititatives to evacuate the fly ash from ash dykes.

We have got requests from M/s VLPL and TRC whose site is at parsada road (4.5 acres), nearby chiraipam and also from M/s RIPL at Khairpur (18.5 acres) land, Kirodimal Nagar Nigam Limited site.

  1. We have developed O.P (Standard Operating Procedure) for processing the requests from persons / parties as followed:
  • Submission of written ‘Request Letter ‘ (standard format made by JSPL)
  • Attach ‘NOC from Local Bodies’ (e.g. Gram Panchayat)
  • Attach the land registration documents.(The actual documents of a requestor shown in the following)
  • The request shall be submitted to HOD-PP who after physical verification of site- location

and approach conditions, if satisfied will continue following procedure.

  • Forward the Request to Executive .Director.
  • After getting clearance from E.D. instructed the party to make, boundary formation around

the site to avoid any out flow of fly ash to surroundings. 

  • A letter of ‘ Intimation to Regional Officer(RO) of CECB,Raigarh’ sent as a formality from Environment ManagementDepartment(EMD).
  • After the preparation of sites the vendor ordered for shifting of fly ash to dumping sites.
  • And as part of the JSPL Vehicle Safety policy, the vehicles (e.g., Dumpers )which going to be engaged shall be got checked and issued the permit.
  • Security deptt also informed about the shifting activity and also the path of movement vehicles decided.
  • Logistics deptt informed for the Weighment of Vehicles (i.e., Dumpers with Gross/Tare Weight).
  • Vendor(s) ordered in such a manner that within their scope all activities included:
  • Excavation of fly ash from A.D. by proclaim
  • Shifting of fly ash by Dumpers (10 wheeler)
  • Dozing the fly ash at dump site by dozer
  • Dampening the dust with help of water spraying by deploying water tankers.

 

About the Author

RAMA NADHAM  DEVULAPALLY had obtained Graduation in Mechanical Engineering,B.Tech.from Jawaharlal Nehru Technological University, Hyderabad (AP). Also acquired Diploma in Industrial Safety,DIS from Annamalai University, TN. And conferred as Chartered Engineer, C. Engr. also honoured as Member,MIE by Institution of Engineers (India). In addition, got ‘Boiler Operation Engineer-proficiency’,BOE from Govt of Karnataka. And also accredited as Energy Manager & Auditor, EM&A by Bureau of Energy Efficiency(BEE). Apart from these qualified as ‘Lead-Auditor of ISO-9001&14001’. Involved in O&M of Power Plants and contributed innovations in the field of Energy Efficiency,Safety,Systemization,etc. 

About The Author