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Transcript of 88361 Coal Brochure Final Web
Gasificationunderground coalgasification:converting unmineablecoal to energy
w w w . g a s i f i c a t i o n . o r gw w w . g a s i f i c a t i o n . o r g
4301 North Fairfax Drive, Suite 300
Arlington, VA 22203
703.276.0110
4301 North Fairfax Drive, Suite 300
Arlington, VA 22203
703.276.0110
©Copyright by the GTC 2012.
w w w . g a s i f i c a t i o n . o r g 1
IntroductIon
currently, about 1.5 billion people –almost a quarter of the world’s popu-
lation—are without electric power. The International Energy Agency
estimates that world energy demand (for all forms of energy, including
transportation fuels) will increase by 36 percent by 2035 and fossil fuels, such
as coal, will continue to play a critical role in meeting this demand.
GasIfIcatIonUndergroUnd Coal gasifiCation:Converting UnmineableCoal to energy
(Courtesy of the UCG Association)
GasIfIcatIon Converting Unmineable Coal to energy2
However, only about 15 percent of the known coal deposits in the world
are economically mineable. Thus, about 85 percent of the world’s coal
resources (about 1.7 trillion tonnes) are “unmineable” because of economic,
environmental, or technical reasons. For example, such coal may be too
deeply underground or buried offshore. This “stranded” coal represents an
untapped energy source. Underground coal gasification (UCG) can unlock
the energy potential in this stranded coal while performing well within all
environmental requirements.
GasIfIcatIon ProductsAbove-ground gasification has been used worldwide on a commercial scale
for more than 75 years by the chemical, refining, and fertilizer industries and
for more than 35 years by the electric power industry. More recently, it is being
adopted in smaller-scale applications and in new settings to solve the problem
of waste disposal by extracting the valuable energy contained in that waste,
and to utilize alternative renewable feedstocks, such as biomass.
The syngas produced from UCG is similar to that produced by above-ground
gasification and it can likewise be combusted in a gas turbine to produce
electricity or further processed to produce chemicals, transportation fuels,
substitute natural gas, hydrogen, or fertilizers.
w w w . g a s i f i c a t i o n . o r g 3
What Is GasIfIcatIon?Gasification is a unique process that transforms any carbon-based material,
such as coal, other fossil fuels, biomass, or secondary recycled materials,
into energy without burning it. Instead, gasification converts materials into
a gas by creating a chemical reaction. This reaction combines those carbon-
based materials (known as feedstocks) with small amounts of air or oxygen,
breaking them down into a gas composed of relatively simple building block
molecules—called synthesis gas or “syngas”. The syngas consists primarily of
hydrogen and carbon monoxide and, depending upon the particular gasifica-
tion technology and feedstock used, may also contain smaller quantities of
methane, carbon dioxide, hydro-
gen sulfide, and water vapor.
Any pollutants and impurities
contained in the raw syngas can
typically be readily and substan-
tially removed leaving a clean
“synthesis” gas (syngas) that can
be converted into electricity and
valuable products.
In traditional gasification, the
feedstocks and air or oxygen are
injected into a gasifier where a
combination of heat and pressure
causes the gasification reaction.
The resulting syngas is then
cleaned to remove any impurities
and the clean syngas can then be
converted into electricity and/or
other valuable products.
VITRIFIED SLAGBY-PRODUCT
SULFURBY-PRODUCT
GASIFIER
FEEDSTOCK OXYGEN PLANT
GAS CLEAN-UP
CLEAN SYNGAS
TO POWER TO PRODUCTS
THE GASIFICATION PROCESS
GasIfIcatIon Converting Unmineable Coal to energy4
What Is underGround coal GasIfIcatIon?With UCG, the actual gasification process takes place underground, generally
below 1,200 feet depth. Recent advances in well drilling technologies are now
enabling UCG development of coals in the 4000-6000 foot depth range, with
increased environmental protection and process efficiency benefits at these
depths. The underground setting provides both the feedstock source (the
coal) as well as pressure comparable to that of an above-ground gasifier. With
most UCG facilities, wells are drilled on two opposite sides of an underground
coal seam. One well is used to inject air or oxygen (and sometimes steam) into
the coal seam to initiate the gasification reaction. The second well is used to
collect the syngas that is formed from the gasification reaction and to pipe it
to the surface for additional processing and use. A pair of wells can last as long
as fifteen years.
The UCG reactions are managed by controlling the rate of oxygen or air that is
injected into the coal seam through the injection well. The process is halted by
stopping the injection of the oxygen or air. After the coal is converted to syngas
in a particular location, the remaining cavity (which will contain the leftover
ash or slag from the coal, as well as other rock material) may be flooded with
w w w . g a s i f i c a t i o n . o r g 5
saline water and the wells are capped. However, there is a growing interest in
using these cavities to store carbon dioxide that could be captured from the
above-ground syngas processing. Once a particular coal seam is exhausted,
new wells are drilled to initiate the gasification reaction in a different section
of the coal seam.
UCG operates at pressures below that of the natural coal seam pressure, thus
ensuring that materials are not pushed out into the surrounding formations.
This is in sharp contrast to hydraulic fracturing operations in oil and gas
production, where pressures significantly above natural formation pressure are
used to force injectants into the formation.
FEEDSTOCK
HYDROGEN FOROIL REFINING
CONSUMERPRODUCTS
SUBSTITUTENATURAL GAS
CHEMICALSFERTILIZERS
TRANSPORTATIONFUELS
POWER
STEAM
SYNGAS
GA
SIFI
CA
TIO
N
GASIFICATION PRODUCTS
GasIfIcatIon Converting Unmineable Coal to energy6
Converting Unmineable Coal
The International Energy Agency estimates that developing countries will
account for 93 percent of the projected increase in global energy demand and
that global demand for fossil fuels, including coal, will account for over 50
percent of the increase in total primary energy demand. (See www.iea.org.)
UCG can help meet this rising energy demand by converting coal to energy and
other products, utilizing resources that otherwise would be too deep, of poor
quality or simply not economical enough to mine. Estimates from the U.S.
Department of Energy’s Lawrence Livermore National Laboratory suggest that
UCG could help increase the recoverable coal reserves in the U.S. by as much
as 300-400 percent, without the need to develop coal mines to tap this energy
source. The World Energy Council estimates that UCG could potentially
increase the world’s recoverable coal reserves by 600 billion tonnes. In addi-
tion, UCG effectively utilizes up to 85 percent of the original heating value of
the coal; a much higher overall efficiency than conventional coal mining and
subsequent combustion boilers.
Carbon dioxide
In the traditional gasification system, carbon dioxide can be captured using
commercially available processes before it would otherwise be vented to the
atmosphere. For most gasification applications, except electric power genera-
tion, carbon dioxide capture is actually required by the process design as part
of the overall syngas cleaning. For electric power generation, and as part of
the process to adjust syngas composition for other gasification applications,
a process, called the water-gas shift reaction, (illustrated next page) is used to
convert the carbon monoxide in the syngas stream into carbon dioxide mol-
ecules that can be captured. Capture of carbon dioxide from syngas has been
commercially practiced for decades in the non-power gasification applications,
such as for the production of chemicals, fertilizers or hydrogen.
w w w . g a s i f i c a t i o n . o r g 7
Capturing the carbon dioxide prior to combustion is more economical than
removing carbon dioxide after combustion, effectively “de-carbonizing” or, at
least, significantly reducing the carbon in the syngas. Captured carbon dioxide
can be injected into declining oil fields for enhanced oil recovery and perma-
nent carbon dioxide storage. The oil industry has been using this technique
with naturally occurring carbon dioxide for over thirty years to increase the
output of older production fields.
co2 removal floW
GasIfIcatIon Converting Unmineable Coal to energy8
In addition, captured carbon dioxide can be injected into other deep coal
seams for enhanced coal bed methane recovery. The injected carbon diox-
ide displaces the methane (used as a substitute natural gas) and the carbon
dioxide is then absorbed into the coal itself.
Carbon dioxide can be captured from UCG operations as well using the same
capture technologies as used in traditional gasification plants. This captured
carbon dioxide can then be used for enhanced oil recovery or enhanced coal
bed methane permanent geologic storage. One advantage of UCG is that the
depleted coal seams used for UCG may also potentially be used as locations
for permanent sequestration or storage of any carbon dioxide produced and
captured from the process.
UCg’s eConomiC benefits
There are a number of significant economic benefits associated with UCG that
include:
ÂÂ No need for coal mining
ÂÂ No need for coal handling
ÂÂ No need for coal transportation
ÂÂ No need to prepare the coal to be fed into a reactor
ÂÂ No need for ash or slag disposal
ÂÂ Carbon dioxide can be captured and used for Enhanced Oil Recovery
or Enhanced Methane Recovery or other permanent geologic storage
w w w . g a s i f i c a t i o n . o r g 9
UCg’s environmental benefits
ÂÂ Minimal land use
ÂÂ Underground saline water may be used to reduce the use of drinkable
groundwater or freshwater
ÂÂ Fewer environmental impacts traditionally associated with coal
mining and handling
ÂÂ Coal seams being gasified are located well below fresh drinking water
supplies (the deeper the UCG, the greater the degree of isolation from
fresh water aquifers)
ÂÂ Significantly reduced criteria air pollutants compared to conventional
coal combustion plants
•Â All or a substantial portion of the sulfur, mercury, arsenic, tar, ash
and particulates found in coal remain underground
•Â Any sulfur or metals that reach the surface do so in a chemically
reduced state, making them easier to remove
ÂÂ No landfill disposal is required for ash or slag
UCg market
UCG was first developed in Europe in the late 1800s, but not commercially
developed until the 1920s and utilized primarily in the former Soviet Union.
Today, with the advancement of new drilling technologies from the oil and
gas industry, the UCG market is global. There are currently commercial scale
projects in Europe, Australia, and South Africa, plus others at the pre-commer-
cial pilot feasibility stage in the USA, New Zealand, Russia, Pakistan, United
Kingdom, Eastern Europe, Chile, Turkey and China. China has the most
extensive modern UCG development program to date. (see map next page)
GasIfIcatIon Converting Unmineable Coal to energy10
Ru
ssia
: 2
01
1 P
roje
ct
sta
rte
d in
Kem
ero
vo,
Sib
eri
a. L
on
g h
isto
ry o
f U
CG
act
ivity
Bel
giu
m:
EU
tri
al a
t T
hu
lin in
1
98
7. N
o f
urt
he
r U
CG
act
ivity
. R
ese
arch
inte
rest
Ser
bia
: L
oo
kin
g to
sta
rt r
ese
arc
h
soon
. P
ote
ntia
l co
al s
ou
rce
s in
vest
iga
ted
Po
lan
d:
EU
HU
GE
p
roje
ct,
incr
ea
sin
g in
tere
st a
nd
re
sea
rch
, su
itab
le
com
me
rcia
l site
s id
en
tifie
d.
Ch
ina:
Lo
ng
his
tory
of
pilo
ts, t
rain
ing
of m
any
. N
ew
pro
ject
s p
lan
ne
d a
t Y
i He
co
al f
ield
an
d
Ula
nch
ap
Inn
er
Mo
ng
olia
. O
the
r p
roje
cts
in r
eg
ion
at
pla
nn
ing
sta
ge
.
Slo
van
ia:
UC
G u
nde
r re
vie
w f
or
suita
bili
ty.
Kaz
akh
stan
:
Site
s id
en
tifie
d b
ut
com
plic
ate
d a
pp
rova
l p
roce
ss h
amp
ers
pro
gre
ss
Bu
lgar
ia:
Tw
o p
roje
cts
un
der
re
vie
w.
Ext
ens
ive
re
sea
rch
so
me
with
EU
b
ack
ing
.
Tu
rkey
: U
CG
pro
ject
at
pla
nn
ing
sta
ge
, se
vera
l su
itab
le s
ites
ide
ntif
ied
.
Can
ada:
Ad
van
ced
re
sea
rch
in
Alb
ert
a a
nd
No
via
Sco
tia.
Sw
an
n H
ills
pilo
t at
se
con
d
sta
ge
. M
an
y su
itab
le c
oa
l se
am
s id
en
tifie
d.
US
A:
Pro
ject
at
Co
ok
Inle
t,
pla
ns
to g
o co
mm
erc
ial i
n 2
015
Lo
ng
his
tory
of r
ese
arc
h/
pilo
t st
ud
ies
& m
ajo
r tr
ials
in 1
95
0s
an
d 1
98
0s.
Su
bst
an
tial i
nte
rest
a
nd
ne
w p
roje
cts
pla
nn
ed
for
Wyo
min
g,
Mo
nta
na
, N
ort
h
Da
kota
, C
olo
rad
o,
Ala
ska
.
Bra
zil:
De
mo
nst
ratio
n
pro
ject
pla
nn
ed,
te
chn
ica
l re
sea
rch
co
ntin
ue
s,
seve
ral s
uita
ble
site
s kn
own.
C
hile
: Jo
int
UC
G
pro
ject
to s
tart
20
12.
Co
lom
bia
: U
CG
pro
ject
p
lan
ne
d, s
eve
ral s
uita
ble
si
tes
ide
ntifi
ed
, co
ntin
uin
g re
sea
rch
.
So
uth
Afr
ica:
UC
G
pro
ject
at
Ma
jub
a is
th
e m
ost
ad
vanc
ed
. E
xte
nsi
ve h
isto
ry o
f re
sea
rch
an
d h
ug
e
am
ou
nt
of in
tere
st
an
d e
xpe
rie
nce
.
Bo
tsw
ana:
UC
G s
een
as
key
to m
axi
mis
ing
its
21
0
bill
ion
to
ns o
f co
al.
No
p
roje
cts
yet
an
no
unce
d.
Se
vera
l la
rge
are
as
suita
ble
.
Ind
on
esia
: S
eve
ral M
OU
s si
gn
ed
aft
er a
pp
rop
ria
te s
ite
sele
ctio
n.
La
ck o
f lic
ensi
ng
st
ruct
ure
.
Ind
ia:
Go
vern
me
nt
loo
kin
g a
t U
CG
to
util
ise
the
60
%
of
its 2
70
bill
ion
ton
ne
s o
f u
nm
ina
ble
co
al.
Ma
ny
suita
ble
New
Zea
lan
d:
Pilo
t p
roje
ct c
ont
inu
es
at
Hu
ntly
We
st,
no
w in
its
thir
d y
ea
r. O
ther
o
pe
rato
rs s
ee
kin
g
po
ten
tial s
ites.
Au
stra
lia:
UC
G
pro
ject
s in
Qu
ee
nsl
an
d,
at
Ch
inch
illa
&
Blo
od
wo
od
Cre
ek.
V
icto
ria
an
d S
ou
th
Au
stra
lia a
lso
d
eve
lopi
ng
pro
ject
s .
Ban
gla
des
h:
UC
G a
ctiv
ity
pla
nn
ed
bu
t no
lic
en
ces
yet
aw
ard
ed
.
Vie
tnam
: T
wo
pro
ject
s in
Re
d R
ive
r D
elta
re
gio
n a
t pla
nn
ing
sta
ge
. H
isto
ry o
f re
sea
rch
.
Uzb
ekis
tan
: W
orl
d’s
o
lde
st U
CG
(5
0+ y
ears
) a
t A
ngr
en
.
EU trial at Tremedal
finished 1998. Further
research continues for
I licence awarded in Dublin
18 UCG licences awarded, all
coastal regions, all off shore.
Licensing and regulations
Irel
and
: O
ne
lic
en
ce D
ub
lin B
ay.
Sp
ain
: E
U t
ria
l at
Tre
med
al
finis
hed
199
8.
Fu
rthe
r re
sea
rch
co
ntin
ue
s fo
r su
itab
le s
ites.
UK
: 1
8 U
CG
lice
nce
s a
ll o
ff s
ho
re.
Lic
ensi
ng
a
nd
re
gu
latio
ns.
a
dva
nce
d.
Cze
ch R
epu
blic
: U
CG
un
der
re
vie
w
as
suita
ble
site
s id
en
tifie
d.
Hu
ng
ary:
Th
e M
ecs
ek
Hill
s p
roje
ct c
on
tinu
es.
F
urt
her
site
s a
nd
exp
an
sio
n o
f a
ctiv
ity
pla
nn
ed
in 2
01
2.
Ro
man
ia:
Te
chn
olo
gy
be
ing
re
view
ed.
Jap
an:
Incr
ease
d
rese
arc
h a
nd
site
id
en
tific
atio
n.
Pak
ista
n:
Th
ar
Sin
dh
Pro
vin
ce,
UC
G p
ilot
pro
ject
e
xpe
cted
to
p
rod
uce
10
0M
W
of
ele
ctri
city
by
the
en
d o
f 2
01
3.
Slo
vak
Rep
ub
lic:
re
sea
rch
, su
itab
le
site
s, M
oU
s si
gn
ed
(Cou
rtes
y of
th
e U
nd
ergr
oun
d C
oal G
asifi
cat
ion
Ass
ocia
tion
)
w w w . g a s i f i c a t i o n . o r g 11
UCG does face a number of issues, including:
ÂÂ A number of coal seams may not be suitable for UCG because of
geologic or hydrologic conditions, particularly at relatively shallow
depths.
ÂÂ Project economics may be uncertain until a number of UCG projects
are in commercial operation.
ÂÂ Site selection needs to be done properly to avoid any potential for
groundwater contamination and surface subsidence for shallow UCG
projects.
These issues can be mitigated through careful project design, site selection,
and monitoring and these are not usually issues for deep UCG projects. UCG
has enormous potential to allow the world to take advantage of coal resources
that would otherwise be too expensive or difficult to reach. UCG can help
address the global energy challenge.
For more information about gasification see www.gasification.org.
For additional information on UCG, see www.ucgassocation.org.
Gasificationunderground coalgasification:converting unmineablecoal to energy
w w w . g a s i f i c a t i o n . o r gw w w . g a s i f i c a t i o n . o r g
4301 North Fairfax Drive, Suite 300
Arlington, VA 22203
703.276.0110
4301 North Fairfax Drive, Suite 300
Arlington, VA 22203
703.276.0110
©Copyright by the GTC 2012.