Underground Coal Gasification - India & Global
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Transcript of Underground Coal Gasification - India & Global
UNDERGROUND COAL GASIFICATION
MOHAMMED KABIRUDDIN University of Petroleum & Energy Studies
UCG PRINCIPLES & ESSENTIALS
Underground Coal Gasification (UCG) converts coal into a gaseous form (syngas) through the same chemical reactions that occur in surface gasifiers
The economics of UCG look promising as capital expenses should be considerably less than surface gasification
Essentials:
Site location -biggest issue
Coal characteristics–operations
Technologies-connecting wells
INTRODUCTION
The technology was first widely used in the USA during the later 1800s.
India in Calcutta (Kolkata) and Bombay (Mumbai) in early
1900.
Lamplighters in many cities used to light streetlights by “town gas”, the product of early and relatively crude forms of coal gasification.
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INTRODUCTION
1912 Co. Durham UK First Test
1930’s Intensive Soviet Development
1950/60’s Early European Trials – inc.
1955 Newman Spinney – Ntl Coal Board
1970/80’s US Programme - 6 Major Trials
1980’s European Studies and First Trial
Early 1990’s First US commercial designs
Mid to late 1990’s El Tremedal, Spain
European Trial
DTI UCG Initiative (1999-2005)
Australian Pilot
Firth of Forth Feasibility Study
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WHY UCG NOW?
Security of supply
– indigenous coal
– Un - mineable coal
• Carbon Capture & Storage
– Pre-combustion processing
– Local storage options
Advances in UCG Technology
– Drilling, completion, control
Production Costs for clean syngas
– Competitive against natural gas
(EU, US)
Flexibility of Syngas for poly-generation
– Existing or new power stations, GTL,
SNG, H2 and other chemicals
FACTORS AFFECTING UCG DESIGNS
CRITERIA FOR UCG
UCG requires special properties of coal seam:
Coal seam lays underground between 100 and 600 metres (preferably more than 300 metres)
Thickness is more than 5 metres
Ash content is less than 60%
Minimal discontinuities in seam
No good water aquifers
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US SITE SELECTION CRITERIA
HOW DOES UCG WORK?
Step 1: Find the coal
Step 2: Drill the boreholes
Step 3: Link the boreholes
Step 4: Ignite the coal
Step 5: Inject the O2 and steam
Step 6: Extract the syngas
WORLD STATUS
WORLD SITES
UCG SITES
UCG SITES
US
31 tests involving DOE, Gulf, Texas A&M, GRI,
ARCO
Rocky Mountain Trial, 14,000 tons of coal 93
days
Oxygen Fired CV 9-11 MJ/m3
Commercial scheme for ammonia production
developed – not constructed
UCG HARNESS
Worldwide UCG operations experience with respect to coal seam
depth and thickness(2004).
ANGREN UCG POWER STATION, UZBEKISTAN
UCG Co-fired
Plant operating for 30 years
UCG used in dedicated 100MW steam turbine
Linc Energy have bought a majority stake in the plant
UCG IN SOUTH AFRICA Eskom UCG Trial at
Majuba Coal field, 3.5m thick at 300m depth (Jan 2007).
Air-blown co-fired 350MWe IGCC unit planned
Sasol initiated a new
UCG trial project at Secunda as a potential feedstock for CTL Plant.
CHINA
China has over 50 large coal gasification facilities nationwide.
China has executed at least 16 pilots since
1991,
And has invested in extensive research
programs at China University of Mining Technology in Beijing.
INDIA & WORLD
There is over 5 million PJ of resource for UCG gas in the United States, 2.2 million PJ of UCG gas in China, and 1.9 million PJ of UCG gas available in India.
The Lawrence Livermore National Laboratory (USA)
has estimated that recoverable reserves could be increased by at least 300% to 400% and that 1.6 trillion tons of un-mineable coal in the USA may be recoverable with UCG.
AUSTRALIA
The World Energy Council’s 2007 Survey on
Energy
Resources estimates that 45% of Australia’s
proven in place reserves, or 44 billion tonnes, is
available for extraction by UCG.
Applying this same proportion to Queensland’s
measured plus inferred sources of thermal coal,
suggests that there are possibly 16 billion tonnes
that may be available for UCG in Queensland.
AUSTRALIAN DEVELOPMENTS
Linc Energy,
– Successful share offering in 2006, now
worth $1.5B
– Development of a GTL plant is underway
– New projects starting in S Australia, Vietnam & USA (Dec 08)
Carbon Energy (2006)
– Joint venture with CSIRO gas now started
(Oct 2007)
Cougar Energy (2007)
– Site for 400MW CCGT Plant in S Australia
– Using Ergo energy.
THE CHINCHILLA UCG FACILITY
THE CHINCHILLA UCG FACILITY
AUSTRALIA
AUSTRALIA
OTHER FEASIBLE AREAS
Indonesia
Vietnam
Pakistan (Thar Coalfield Power & GTL)
Japan
Chinese Mining Companies, e.g. Xinwen, Ezhuang
Mongolia
New Zealand (Solid Energy)
INDIA
GAIL also plans to set up a coal gasification project in eastern India (Durgapur, Haldia, and Talcher) to produce 3.4 MSCMD of syngas.
In September 2005, GAIL has signed an memorandum with the Shaanxi Huashan Chemical Industry group of China to undertake coal gasification activities in the Shaanxi province.
INDIA
GAIL (India) Ltd has signed a memorandum of
cooperation with Ergo Exergy Technologies Inc., Canada, to explore UCG projects in India.
Ergo Exergy will help GAIL to
i) determine the technical and economic viability of each project ii) bring in efficient drilling techniques and
production of UCG gas in commercial quantity with quality.
NTPC VIEW
UCG IN INDIA
The Neyveli Lignite Corporation Ltd. (NLC), which has
got Government approval for taking-up a UCG Project
in lignite deposits of Rajasthan, has not been able to
get a suitable technical partner, so far.
• The Reliance Industries Limited (RIL) has been
exploring possibilities for taking up a UCG project in
India.
UCG IN INDIA
ONGC, while drilling in search of hydrocarbons, discovered large reserves of coal at depths more than 600m.
These are spread in Gujarat and West Bengal and
have been estimated to contain more than 350bt of coal deposit.
In Gujarat alone, these coal reserves have been
estimated to be around 63 bt in Mehsana-Ahmedabad block and 60 bt in Patan-Tharad block.
UCG IN INDIA
The energy estimated for Mehsana - Ahmedabad block alone, is equivalent to about 15,000 bcm of natural gas.
The ONGC is conducting a pilot test in Mehsana area
at an estimated cost of Rs 9.60 crores.
• An Information Well – UCG-1 – was drilled in 1986 to
a depth of 1005m at the selected site.
ESTIMATED RESERVES FROM WEC 2008
POSITIVE FACTORS
1. UCG is the only feasible technology, which enables exploitation of deep (> 700m) coal reserves, which are not amenable to known conventional mining methods.
2. UCG offers an environmentally clean way to harness energy from coal.
3. UCG brings no solid waste to the surface.
POSITIVE FACTORS
4. Even at shallower depths (< 500m), UCG can be more
economical than conventional mining.
5. UCG reduces capital investment, operating costs, and
the output gases cost by 25 to 50% as compared to
surface gasification.
6. Possibilities of transport of medium calorific value gas
over a distance of 100 km. exist.
POSITIVE FACTORS
7. Possibilities of using CO2 from the gas for enhanced
oil recovery exist.
8. Basic UCG technology is known.
9. Conditions in India are far more compelling for
adopting UCG than most locations in the world.
ANNUAL CASH FLOW FOR 1,000MW UCG GAS PLANT WITH CO2
CAPTURE (CO2 $20/TONNE)
Internal rate of return 25-30%, (with storage)
CO2credit 32% of
revenue Syngas Utilisation
Options
480 Mwe electrical
power 10,00 bb/d diesel
savings
ADVANTAGES:
Much higher coal extraction – up to 95%
No pillars
Multiple seams
Thick and thin seams
More economic – less capital expenditure
Economic on a smaller scale
Potential to be cleaner technology – smaller
environmental footprint
Little or no rehabilitation required
No fine coal
No Ash
Safer
DISADVANTAGES
Potential for contamination
Controllability of the reaction
CONCLUSION
Viable alternative mining method for otherwise unminable coal
Potential smaller environmental footprint than
conventional process
Better utilisation of coal reserves