Presentation on Underground Coal Gasification for Footprints. Won the first place !

2. • Introduction
• Why UCG?
• Process Description
• Benefits
• Demerits
• World Scenario
• Conclusion

3. Underground coal gasification (UCG) is an industrial process,
which enables coal to be converted into product gas.
UCG is an in-situ gasification process carried out in non-
mined coal seams using injection of oxidants, and
bringing the product gas to surface through production
wells drilled from the surface.
It is a complex process involving
Chemical reactions
Heat and mass transfer
Complex flow dynamics
Growing cavity dimensions

4. Coal is a readily combustible black or brownish-
black sedimentary rock normally occurring in rock
strata in layers or veins called coal beds
Composition
Primary carbon
Secondary sulfur,
hydrogen,
oxygen,
nitrogen

5. Energy market scenario
High and ever-increasing fuel prices.
A rising energy consumption in the Developing World.
Growing shortages of supply of oil and natural gas.
Depletion of several major natural gas fields across the
world
Energy market dynamics are unfolding on mounting
concerns about global warming.

6. Characteristics of the coal seam i.e. permeability, fault
structure of local strata , geology and hydrogeology of
area which surrounds target coal seam should be
known.
Drilling of pilot bore holes to coal seam depth for coring and
seam characterization.
Seismic survey / 3D survey of whole area
Modeling of hydrogeology to meet ground water
requirements.

7. Underground coal gasification projects have specific
requirements regarding the coal seam:
The seam lies underground at a depth of between 30 and 800
meters
The seam thickness is more than 5 meters;
The ash content of the coal is less than 60%;
The seam has minimal discontinuities; &
There are no aquifers nearby (to avoid polluting supplies
of drinking water).

8. Responsible UGC projects
require careful site selection
and evaluation to identify
deep coal seams that are at
least 650 feet below the
surface. UCG coal beds are
below fresh water aquifer,
isolated from fresh water
and contained by strong,
impermeable overlying rock
layers

9. The process begins by drilling two wells in
a coal seam

10. At one well, operators inject an oxidant
such as air to start a carefully controlled
combustion reaction

11. Heat and pressure convert the coal to
gas:
coal+water+oxygen+heat=Hydrogen, CO

12. Operators control or halt the process by
managing oxygen supply. Natural water
Influx quenches the reaction, eliminating
the possibility of unwanted coal seam fires.
Ash and other byproducts remain
underground

13. Gas moves through porous coal seam.

14. The second well produces syngas to
surface for processing.

15. Processing and clean up at the surface
Prepare syngas for near-site use or
transport. Syngas is an energy rich gas
product that can be handled and used like
natural gas; piped, stored or used to fuel a
turbine to generate electricity and
upgraded or converted to make synthetic
natural gas or liquid fuel.

16. UCG with carbon capture and
sequestration leaves a carbon
footprint that is far smaller than
conventional coal and similar to
natural gas.CO2 is easily separated
from syngas using existing
technologies for underground
sequestration. Commercial scale
carbon capture has successfully
removed CO2at surface coal gasifier
plants

19. Many experiments have been carried out to develop
mathematical models for UCG which can be used for
carrying out process calculations.
The best suitable match is a MFR followed by a PFR.
MFR
PFR

20. UCG offers significant benefits, financial, social and
environmental, over traditional coal mining or coal gasification
methods.
Environmental benefits
Financial benefits
Social benefits

21. Lower capital and operating costs .
Reduced cost of plant installation - No Surface Gasifier.
Syngas can be piped directly to end-user, reducing need of
rail / road infrastructure.
Lowers cost of environmental clean up due to solid waste
being confined underground
GT power plants can be switched from natural gas to
cheaper UCG product gas.

22. UCG may not require an external water source to operate, a major
environmental advantage over water-intensive coal mining
operations and pulverized-coal-fired energy production methods
Lower emissions, because gasification in UCG is underground
thereby reducing environmental management costs
Particulates are generated at half the rate of their surface
equivalents and stay underground
Lower dust, noise, visual impact on the surface
Low risk of surface water pollution
Reduced methane emissions - coal seam gas is recovered in the
process, rather than lost in the atmosphere as in most conventional
mining
No dirt handling and disposal at mine sites

23. No coal washing and fines disposal at mine sites.
UCG process creates an immense underground gas and heat storage
capacity, which makes the gas supply very stable and robust.
USE UCG AND SAVE THE ENVIRONMENT

24. Risk of injury or death to humans is significantly reduced
since workers need not to enter a mine.
Local communities no longer face air pollution
As mining isn't involved and land degradation reduces
keeping surrounding land fertile .

25. UCG Gas gives 25% increase in the gas turbine power output
compared to natural gas.
Fewer air emissions: greenhouse gas emissions as low as 30%
than natural gas.
Cost of power generation is much less than with natural
gas.
UCG gas can be produced in abundance for years to come
and used to fuel GT plants .

26. UCG uses un mined coal and performed in underground
coal seams compared to conventional gasification
It eliminates cost of coal mining & transport
It does not require capital cost of the surface gasification
reactor.
UCG does not incur cost of ash and slag removal,
storage and disposal all inert solids remain underground.
UCG is usually produced at lower temperature, easier to
process and clean up.
Unlike UCG, conventional gasification requires coal mining
with environmental and safety issues.
Conventional gasification uses large volumes of water
whereas UCG uses groundwater present in coal seam.

27. Visual and acoustic Environmental impacts.
Air emissions (tough low) and groundwater impact.
Geological and hydro geological risks. The voids from which
gas is removed become weak .
But with an optimistic approach and technological advance
we can overcome these.

28. In the last few years there has been significant renewed interest in UCG as the technology has
moved forward considerably.
China has about 30 projects in different phases of preparation that use underground coal
gasification.
India plans to use underground gasification to access an estimated 350 billion tonnes of coal.
In 2007 India compiled a 93-page status report on underground coal gasification that
highlighted interest from many of the country's biggest companies. Jindal power coming up
with its plant in orissa.
South African companies Sasol and Eskom both have UCG pilot facilities that have been
operating for some time, giving valuable information and data.
In Australia, Linc Energy has the Chinchilla site, which first started operating in 2000. Carbon
Energy has completed a successful 100 day commercial scale study in Bloodwood Creek in
2008.
Demonstration projects and studies are also currently under way in a number of countries,
including the USA, Western and Eastern Europe, Japan, Indonesia, Vietnam, India, Australia
and China, with work being carried out by both industry and research establishments.
A number of issues remain to be resolved before wider deployment can be achieved

30. Today high prices of oil and gas and uncertainties about
political stability is most of oil producing countries, have
renewed interest in all kinds of fuels. A renewable interest
in coal gasification is therefore not surprising. Further-
more, hydrogen is now a welcome by product because of
current interest in alternatively fuelled vehicles. Ultimately,
it could be a substitute for deep mining coal for power
generation use.

31. ADOPT UCG
Save the
world

32. Chemical Weekly ,8 march 2011
Online references:
www.ErgoExergy.com
www.ucgp.com
www.syngasrefiner.com
www.cirienergy.com

33. Thank You
Made by
Dev Mehta
Sapna Budhwani
FTE MSU