Ajay K. Singh and Amalendu Sinha
Co2 Storage Potential in Unmineable Coal Seams in India
Central Institute of Mining and Fuel Research(Erstwhile Central Mining Research Institute)
Barwa Road, Dhanbad – 826 001
Speaker
Ajay K. Singh
CO2 Sequestration in Geologic Formations
One of the options for mitigating the GHG effect is to
sequester CO2 in geologic formations.
The geologic formations are
i. Depleted oil and gas reservoirs
ii. Use of CO2 in EOR.
iii. Deep unmineable coal seams
iv. Use of CO2 in enhanced CBM recovery
v. Deep saline water-saturated reservoir rocks
vi. Other suggested options (basalts, oil shales, cavities)
Coal and Lignite Deposits in India
Gondwana- Nearly 99.7 per cent bituminous
to subbituminous coal of India
is available in the Lower
Gondwana in the eastern region
of India located in West Bengal,
Jharkhand, Madhya Pradesh,
Chhattisgarh, Orissa, Andhra
Pradesh and Maharashtra
provinces. Tertiary- Tamilnadu, Kerala, Gujarat and
Himalayan foot hills from Pir
Panjal of Jammu and Kashmir
to Abor Hills and Kuen Bhum
range of Arunanchal Pradesh.
Deep seated lignite in region of
Kalol of Cambay basin, Gujarat
and Barmer–Sanchor basin in
Rajasthan.
Geological Resources of coal as on 1.1.2007 in India (By GSI)
State Coal resources in Million tons
Proved Indicated Inferred Total
Andhra Pradesh 8475 6328 2658 17461
Arunanchal Pradesh 31 40 19 90
Assam 315 27 34 376
Bihar 0 0 160 160
Chhattisgarh 9872 27035 4443 41450
Jharkhand 36881 31094 6338 74313
Madhya Pradesh 7584 9259 2934 19777
Maharashtra 4856 2822 1992 9670
Meghalaya 118 41 301 460
Nagaland 4 1 15 20
Orissa 17464 30239 14296 61999
Uttar Pradesh 766 296 0 1062
West Bengal 11454 11810 5071 28335
Total 95920 118992 38260 255172
Potential Coalbeds for CO2 Storage in India
The potential sites for CO2 storage in coalbeds of Indian basins have been identified
with due consideration of accepted exploration norms, depth wise resource distribution quality wise abundance and mining status of coal.
Identified candidates for CO2 storage in India.
Category of coal beds Grade of coal Candidates /Basins
Unmineable Coalbeds in explored areas
Power Grade coal SingrauliMand RaigarhTalcherGodavari
Grey Areas Coalbeds Coking coal JhariaEast BokaroSohagpurSouth Karanpura
Superior non coking coal RaniganjSouth Karanpura
Power grade coal Talcher
Concealed Coalfields Tertiary age coal Cambay basinBarmer Sanchor basin*
Power grade coal West Bengal Gangetic PlainBirbhum Domra Panagarh Wardha Valley Extension Kamptee basin Extension
Comparative Adsorption of CO2 and Methane
Studies conducted so far supports stronger affinity of CO2
to the coal molecule.
2 to 3 molecules of CO2 may displace one molecule of
methane
It means carbon dioxide is preferentially adsorbed onto the
coal structure over methane (2:1 ratio).
Methane sorption capacity for Indian coals has been
investigated by CIMFR.
Understanding controls on CO2 and CH4 adsorption in
coals is important for the modeling of both CO2
sequestration and CBM production.
Methane and CO2 Adsorption Isotherm
Methane Adsorption (actually measured)
Estimated CO2 Adsorption
cc/gPressure (atm)Moisture Equilibrated
cc/g
0 0 0
4.91 1.8 3.6
10.99 3.7 7.4
18.08 5.3 10.6
27.91 6.5 13.0
37.62 7.6 15.2
48.04 8.4 16.8
57.14 9.2 18.4
67.69 10.0 20.0
77.20 10.4 20.8
86.98 10.8 21.6
96.57 11.1 22.2
Properties of Potential Coalbeds
Proximate analysis and rank of Unmineable and Grey area coalbeds.
Coalfields Basic parameters(mmf basis)
Other properties Reflectance
VRo%VM(%)
FC(%)
East Bokaro 28-36 85-90 0.85-1.05
South Karanpura 37-40 80-84 0.60-0.80
Jharia -Barakar 17-35 87-93 0.90-1.30
Raniganj 39-44 79-90 0.70-0.85
Rajmahal-Barakar 38-40 78-81 0.45-0.50
Singrauli- Barakar 37-45 78-81 0.45-0.50
Sohagpur 34-40 80-87 0.55-0.65
Pench valley 32-40 82-89 0.50-0.60
Wardha valley 35-40 78-82 0.55-0.60
Godavari Valley 35-42 78-83 0.55-0.60
Talcher 35-45 79-82 0.50-0.55*mmf - Mineral matter free basis
Properties of Potential Coalbeds
Proximate analysis and rank of Concealed coalbeds.
Coalfields Basic parameters(mmf basis)
Other propertiesReflectance
VRo %VM(%)
FC(%)
Cambay basin 45-58 52-68 0.32-0.44
Barmer Sanchor basin 47-60 48-66 0.26-0.40
W Bengal 38-52 65-82 0.42-0.65
Birbhum 16-38 68-86 1.10-1.86
Wardha valley 24-35 72-88 0.54-0.68
Kamptee Kanhan valley 26-36 75-92 0.52-0.66
*mmf - Mineral matter free basis
Unmineable Coalbeds in explored areas
In depth coal resource analysis of Indian territory as per quality, depth wise
distribution and status of exploration has supported in identification of
suitable sites for CO2 sequestration.
The resources reported by GSI and other agencies have been classed as
mineable and unmineable on the basis of the following factors.
- Exploration limit of coal has been to 1200m depth cover.
- Coking and superior grade non coking up to the explored limit has been
classed as mineable.
- Inferior grade non coking coal (Grade E-G) upto 900m depth cover in
Damodar and Mahanadi Valleys have been taken as within mineable limit.
- Mineable limit for inferior grade non coking coal of Godavari and Wardha
Valleys have been taken as 800m due to premium pricing structure.
Unmineable coal and CO2 storage capacity
Coalfield Estimated adsorption capacity of CO2
(m3/t)
UnmineableCoal Reserve
(Mt)
CO2 storage
capacity
(Bm3)
CO2 storage
capacity
(Mt)
CO2 storage
capacity(50%)(Mt)
Singrauli Range 18.0 – 22.0Average 20.0
37.0 0.74 1.46 0.73
Mand Raigarh
Range 16.0-23.0 Average 19.0
79.0 1.50 2.97 1.48
Talcher Range 17.2-24.8Average 20.4
1017.0 20.80 41.18 20.69
Godavari Range 16.8-22.2Average 19.2
1976.0 38.02 75.28 37.64
Grey Area Coalbeds
The extension of coal beds below 1200m depth cover in coking and superior grade non coking coal have not been explored even though the continuity of the coal beds was well indicated within the lineament. The coal beds of such zones beyond mineable limit have been classed as Grey Area reserve.
These reserves in case of East Bokaro, South Karanpura, Jharia and Raniganj and Sohagpur are below 1200m depth cover while in case of inferior grade non coking the limit is 600m for Son Mahanadi Valley and 800m for Wardha Godavari Valley coal fields.
Grey Area Coalbeds
Coalfield Estimated CO2
adsorption capacity
(m3/t)
CumulativeCoal seam thickness
(m)
Block Area (km2)
Coal Reserve
(Bt)
CO2 storage
capacity(Bm3)
CO2
storage capacity
(Mt)
CO2
storage capacity
(50%) (Mt)
South Karanpura
Range 19.5-28.0Average 24.5
73.0 76.0 0.75 18.35 36.33 18.16
East Bokaro Range 22.3-33.5Average 28.1
100.0 113.0 1.53 42.90 84.94 42.47
Jharia Range 22.0-56.0Average 34.5
40.0 193.0 1.04 35.96 71.20 35.60
Raniganj Range 20.8-29.0Average 24.0
30.0 240.0 0.97 23.33 46.19 23.09
Sohagpur Range 18.9-26.4Average 22.6
15.0 450.0 0.91 20.59 40.76 20.38
Talcher Range 17.2-24.8Average 20.4
120.0 149.0 2.41 49.24 97.49 48.75
Grey Area coal reserve and CO2 storage capacity
Concealed Area Coalbeds
The coal beds not covered in resource estimation exercise because of the basalt trap or thick alluvium beds have been classed as concealed coalbeds.
Invariably such beds come under chance discovery during oil and natural gas exploration or drilling for some special missions.
The bottom most coal bearing Barakar formation in such operations has been located within 300m to 3km depth cover over Nagaland to Cambay Basin Gujarat.
Concealed Gondwana Sediments in Gangetic Plain Barmer-Sanchor basin
Continued…..
Coalfield Estimated adsorption
capacity of CO2
(m3/t)
Cumulativethickness of
the coal seams(m)
Area of the block
(km2)
Coal reserve
(Bt)
CO2 storage
capacity(Bm3)
CO2 storage
capacity(Mt)
CO2
storage capacity(50%)(Mt)
Cambay basin Range 13.8-19.6Average 16.7
102.0 6900 63.0 1057.81 2094.45 1047.23
Barmer-Sanchor Basin
Range 128-18.4Average 15.6
100.0 6700 60.0 936.00 1853.28 926.64
W.B. Gangetic plain
Range 16.4-23.2Average 18.3
--- --- 7.2 131.76 260.88 130.44
Birbhum coalfield
Range 17.2-24.8Average 20.2
100.0 312.0 4.2 85.08 168.46 84.23
Domra Panagarh
Range 18.6-25.8Average 21.8
48.0 116.0 0.751 16.39 32.45 16.23
Wardha Valley extension
Range 15.7-22.8Average 17.8
13.0 212.0 0.37 6.62 13.11 6.55
Kamptee Extension
Range 7.2-9.2Average 8.1
14.0 300 0.57 9.81 19.42 9.71
Concealed area coal reserve and CO2 storage capacity
Quantity of CO2 Storage in Indian Coalbeds
Coalfield CO2 storage potential in Mt with 90% saturation level
Total-Mt
Unmineable beds Grey areas Concealed areas East Bokaro x 84.94 x 85South Karanpura x 36.33 x 36Jharia x 71.20 x 71Raniganj x 41.57 x 42Singrauli 1.32 x x 1Sohagpur x 36.70 x 37Mand Raigarh 2.67 x x 3Talcher 37.06 87.75 x 118Godavari-Ramgundam 67.75 x ? 68Cambay Basin x x 1885.02 1885Barmer Sanchor basin X x 1667.95 1668W. Bengal Gangetic Basin
x x 234.80 235
Birbhum x x 151.61 152Domra Panagarh x x 29.20 29Wardha x x 11.80 12Kamptee Coalfield x x 17.48 17Total 4459
CO2 storage capacity in Indian Coalfields
CO2 point Sources and Compatibility of Unmineable Coalbeds
The identified sites are estimated to have 4459 Mt CO2
storage potential, sufficient to store over 20% of total gas emission from the present power plants over their life time.
The sites close to the operating thermal power units may be
the most appropriate for CO2 sequestration as the
transportation cost of the gas will be minimum and the
pollution level of CO2 is alarming (Bradshaw, 2002 and 2003).
The rate of CO2 generation and total CO2, generated within
the life span of a thermal power station; presuming 20 years more from the date.
The sites with storage capacity below 12Mt have been ignored because of their insignificant size.
CO2 storage capacity and point source gas generation in close vicinity
Candidate CO2 storage
capacity(Mt)
Nearest Point Source CO2
generation
Mt in life time(20 yrs)
t/day Mt/year
Cambay 1885 9200 3.36 67
Barmer Sanchor 1668 14600 5.33 107
Godavari 68 200800 73.29 1465
East Bokaro 85 16700 6.10 122
South Karanpura 36 43600 15.91 318
Birbhum 152 26000 9.49 190
Domra Panagarh 29 28400 10.36 207
West Bengal basin
235 103700 37.85 757
Jharia 71 17900 6.53 131
Talcher 118 66700 24.35 487
Sohagpur 37 2175 0.79 16
Raniganj 42 6900 2.51 50
Continued…..
Conclusion
CO2 sequestration potential in Indian coalbeds is
estimated to be 4459 Mt.
Indian coalbed are classified into grey, concealed
and unmineable based on its depth of occurrence
and grade characteristics.
The storage potential howsoever small may help in
minimizing the GHG pollution level.
Storage of CO2 in coal seams may have an added
advantage of enhanced CBM recovery.