new method of extraction

1. Presented by
MD.Saddam Hussain
B tech mining
*Underground coal
gasification

2. INTRODUCTION:
 Mining process is commonly done in two ways
opencast mining and underground mining.
 As the population increasing their artificial needs are
also increasing and by these two methods we are
unable to reach the needs of increasing population.
 Now a days modern methods are implementing in
mining and one of them is UNDERGROUND COAL
GASIFICATION Process.

3.  Underground coal gasification (UCG) is an industrial process
which converts coal into product gas.
 It is an in-situ gasification process carried out in non-mined coal
seams, using injection of oxidants to burn the coal and bringing
the product gas to surface through production wells drilled from
the surface to coal seam.
 The product gas could be used as a chemical feed stock or as fuel
for power generation.
 The technique can be applied to resources that are otherwise
unprofitable or technically complicated to extract by traditional
mining methods and it also offers an alternative to conventional
coal mining methods for some resources.

4. *Underground coal gasification
converts coal to gas. Gas
produced is known as
synthetic gas(syngas) or
product gas.
Gas is produced and
exhausted through wells
drilled into the non-mined coal
seam, The drilled holes are
named as Injection well &
Production well.

5.  Through injection well
oxidants (air, oxygen or
steam) are supplied to ignite
and fuel the underground
combustion process.
 Production well is used to
bring product gas or syngas
to the surface.
 The calorific value is nearly
800 – 1200 K Cal/NM3 and
it may reach up to 1500 K
Cal/NM3 also.

6. Syngas uses

7. This process decomposes coal and generates CO2, CO, H2, N2,
and CH4. In addition to them, there are small quantities of various
contaminants including Sulphur oxides (SOX), mono-nitrogen
oxides (NOX) and hydrogen supplied (H2S). As the coal face burns
and the immediate area is depleted, the oxidants injected are
controlled by an operator. Which helps us to control the flow rate
and burning capacity of the coal.

8. There is no surface impact after completion of UCG
process

9. NEED OF GASIFICATION TECHNOLOGY
Fuel-wise Primary Energy consumption in %.
Coal production has been increasing over the past 10 years, despite
calls for lower emissions and continued research into the
development of alternative energy sources. The International
Energy Association (IEA) predicts an increase in coal usage of 55%
to 2030 as emerging nations develop industrial infrastructure and
the world moves from reliance on depleting supplies of oil and gas.
FUEL INDIA WORLD
Oil 32 37
Natural gas 8 24
Coal 54 27
Nuclear energy 1 6
Hydro electricity 5 6
Total 100 100

10. Coal will increasingly be used but UCG offers, a cleaner,
cheaper and safer method. However nearly 85% of known coal
reserves are deemed un-mineable with surface mining
techniques, being too deep, too remote, and too economical or
of poor quality. The majority of countries with large coal
reserves have few alternative indigenous energy sources. many
of the poorest nations have low rank coals that emit noxious
chemicals and low energy when conventionally mined.
It is in these regions that UCG has much to offer, so many are
now turning to UCG to fully utilize this valuable resource,
which many experts believe could treble the availability of coal
suitable for UCG globally.

11. UCG is especially suitable for low rank coals like lignite and sub-
bituminous coal and bituminous coal.
 The calorific value of bituminous coal is 10,500 to 15,000 Btu
per pound as mined.
 The calorific value of sub bituminous coal is 8,500 to 13,000 Btu
per pound, as mined.
 The calorific value of lignite coal is 4,000 to 8,300 Btu per
pound.
which produces less heat and more CO2 when burned. In addition,
the UCG process is an effective generator of large quantities of
CO2,hydrogen, now in demand as feedstock for the chemical
industry and as an alternative fuel for vehicles

12.  In India most of the mines are closed being coal seams present
but the seam is too deep and it cannot be mined because of some
economic reasons (such as it does not produces sufficient profits
and in other way it causes much losses).
 In India an underground mine depth is not more than 400 to
500mts but we are having coal seams present below 600mts.
 These seams cant be mined due to heavy depths and some reasons
but in such cases we can use the UNDER GROUND COAL
GASIFICATION and we can take the complete coal out in the
form of syngas and we can produce electricity and etc. Without
depending on any others.
 This process is so easy and can be done in depths.

13. ADVANTAGES AND ENVIRONMENTL BENEFITS:
UCG does not cause any type of environmental impacts which are
usually caused by traditional mining methods.
UCG causes much less pollution do not release gases (SOX, NOX
and NOXIOUS GASES) directly into atmosphere.
Coal gasification offers certain environmental benefits compared to
traditional coal fired power units, plants using coal gasification
technology produce much lower carbon emissions and solid waste,
rather the waste products can be valuable for instants, pure sulfur
can be extracted from sulphur dioxide scrubbers.
Methane gas produced during this process can be used as a substitute
for natural gas.

14.  Another example is the chemical synthetic gas which consists of
carbon monoxide and hydrogen. It is the raw material for
producing industrial chemical such as ammonia and methyl
alcohol.
 Compared to the above gasification UCG is much cheaper. Does
not disturb land by mining, leaves ash in its natural location and
allows on operating. UCG plant to increase its syngas production
at minimum capital cost.UCG seems to be most suitable
technology to be used in conjunction.
 With CO2 storage, providing a reduction of greenhouse emissions
compared to surface exploitations.
 The gases released during this process can be processed and used
in chemical industries, fertilizer companies.

15. ECONOMICALBENEFITS:
 UCG is a cheaper process when compared to other coal mining
methods
 UCG does not allow gasifier purchase.
 Coal transport or purchase is not done in UCG.
 In UCG power generation costs is very low.
 The gases produced during UCG can be sold to chemical
factories.
DISADVANTAGES:
The main disadvantage of the underground coal gasification is
ground water contamination. Due to the ground water present at the
processing area the pollutants released are mixed with in the water
and makes it contaminated and poisonous.

16. SUGGESTIONS TO OVER COME DISADVANTAGE:
 Contamination can be prevented by proper siting-UCG plants at the
place where there is no groundwater to be contaminated.
 Isolating the site from current or future ground water sources and
understanding how UCG affects the local hydrology.
 Regular monitoring of the groundwater around the UCG operation
to take appropriate measures.
 Heating and subsidence from UCG might lead to fractures leading
to change in ground water flow. Heated water having low density
and low viscosity may affect ground water flow.
 Where the UCG process has made the surrounding ground water is
permanently declared as unsuitable for irrigation or animal feeding.

17. World wide view of countries using
UNDERGROUND COAL GASIFICATION Process

18. CONCLUSION:
 Coal is the prime energy resources in India.
 Major problems associated with the current coal based
technologies are lower efficiency, environment and consequent
damages there off.
 Coal gasification has been internationally accepted as one of the
most viable and effective clean coal technology for various
applications with limitations

19. “I believe that one day hydrogen and oxygen,
which together form water, will be used either
alone are together as an inexhaustible source
of heat and light”
-Jules Verne,
the mysterious island 1874.

20. *