TECHNICAL FIELD
The present. invention r e l a t e s t o upgraded coal
production equipment, and is p a r t i c u l a r l y u s e f u l when used t o
5 upgrade coal of low rank (low-rank c o a l ) , such as brown coal
or subbituminous coal, which is porous and has a high water
content.
BACKGROUND ART
Coal of low rank (low-rank c o a l ) , such as brown coal or
LO subbituminouscoal, which i s p o r o u s andhas a h i g h w a t e r c o n t e n t
generates alowamountofheatperunitweight, a n d i s t h e r e f o r e
dried through a heating treatment t o have improved amount of
heat generation per u n i t weight.
As upgraded coal production equipment configured t o
15 perform such upgrade of low-rank coal, t h e r e is, f o r example,
equipment including: an i n d i r e c t - h e a t i n g p y r o l y s i s device
which performs p y r o l y s i s on low-rank coal by heating t h e
low-rank coal i n d i r e c t l y by use of a heating gas; and a
combustion furnace which generates t h e heating gas by
20 combusting a p y r o l y s i s gas generated i n the p y r o l y s i s device
and s u p p l i e d t o t h e combustion furnace throuah a p y r o l y s i s uas
supply pipe.
The p y r o l y s i s gas described above is composed of a
low-boiling component. However, since the low-rank coal is
25 processed under a r e l a t i v e l y high temperature, the p y r o l y s i s
gas is accompanied by t a r ( p y r o l y s i s o i l ) which is a
high-boiling component. When the p y r o l y s i s gas is cooled, the
t a r i s attached t o a w a l l surface of a duct or t-he l i k e t h r o ~ i g h
which the p y r o l y s i s gas flows. When a l a r g e amount of t a r i s
30 attached, a p r o b l e m . m i g h t occur, such as clogging thc duct.
Hence, various techniques have been developed t o remove the
t a r .
For example, P a t e n t Document 1 given below d i s c l o s e s a
decoking method f o r combusting and removing coke attached t o
5 the i n s i d e of a pipe by use of n gas which is obtaincd by
a d j u s t i n g a i r t o have an oxygen concentration of 3 vol% t o 2 1
~01%rh rough d i l u t l o n w i t h warer vapor or an i n e r t gas, and
which is a l s o adjusted t o have a temperature of 350 O C t o 500
Patent Document 2 given below d i s c l o s e s a method f o r
p e r f o r m i n g a p y r o l y s i s t r e a t m e n t o n a p r o c e s s e d o b j e c t b y u s i n g
a n e x t e r n a l h e a t i n g k i l n . I n t h i s m e t h o d , anoxygen-containing
gas is supplied i n t o an inner c y l i n d e r of the e x t e r n a l heating
k i l n t o combust a carbide of o r g a n i c m a t t e r i n t h e processed
15 object and/or a combustible gas, which a r e produced by
p y r o l y s i s . Thereby, the temperature of a p y r o l y s i s gas
i n c r e a s e s , so t h a t l i q u e f a c t i o n or s o l i d i f i c a t i o n is
prevented-
PRIOR ART DOC-NTS
20 PATENT DOCIMENTS
Patent Document 1: Japanese Patent Application Publication No.
Hei 5-188653 ( s e e , e . g . , paragraphs [0013], [0017], and the
like)
Patent Document 2: Japanese P a t e n t A p p l i c a t i o n PublicationNo.
25 2004-3738 (see, e-g., paragraphs [0011], [0014], [0015], and
t h e l i k e )
SUbMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
1 tothe upgraded coal production equipmentdescribedearlier,
5 the decoking has to be performed with the py~olysis device
itself being stopped. Alternatively, two systems of ducts
through which the pyrolysis device supplies the combustion
furnace with a pyrolysis gas are provided, and the decoking
has to be performed while stopping one of the systems. This
10 entails decrease in operating rate of the equipment, size
increase, a n d t h e like, causingincreaseincosts for producing
upgraded coal. In other words, the tar cannot be removed
cf ficicntly.
By directly supplyingthe oxygen-concentration adjusted
15 gas adjusted for its oxygen concentration to the pyrolysis gas
supply pipe described earlier, tar produced during operation
is combusted, sb that attachment of the tar to the pyrolysis
gas supply pipe can be si-~ppressed~H nwever, generating the
oxygen-concentration adjusted gas from air or from an inert
20 gas ( n i t r u g e n ur water vapor) r e q u i r e s an a p p a r a t u s specialized -
forthat, andthis increases costs forproducingupgradedcoal.
Moreover, the oxygen-concentration adjusted gas has to be
increased in temperature in advance in order for it to react
with the tar. Thus, additional energy is needed. In sum, the
25 tar cannot be removed efficiently.
In the method for performing a pyrolysis treatment on
a processed object by using an external heating kiln described
in Patent Document 2, the carbide itself of organic matter in
the processed object produced by the pyrolysis is combusted.
30 Thus, when this method is applied to the pyrolysis device of
t h e upgraded coal production equipment, the production volume
of t h e upgraded coal i s lowered.
In v i e w of the above, the p r e s e n t i n v e n t i n n has heen made
t o solve the problems described above, and has an o b j e c t i v e
5 of providing upgraded coal production equipment capable of
e f f i c i e n t t a r removal without lowering t h e production volume
of upgraded c o a l .
MEANS FOR SOLVING THE PROBLEMS
Upgraded coal production equipment according t o a f i r s t
10 aspect of t h e invention f o r solving the above problems is
upgradedcoalproductionequipmentwhichincludes dryingmeans
f o r drying coal, i n d i r e c t - h e a t i n g p y r o l y s i s means f o r
performing p y r o l y s i s on t h e d r i e d coal by i n d i r e c t l y heating
t h e d r i e d coal by use of a heating gas, and cooling means f o r
15 cooling the coal subjected t o the p y r o l y s i s , and which is
c h a r a c t e r i z e d i n t h a t the equipment comprises: heating gas
generationmeans f o r generating the heating gas; p y r o l y s i s gas
supply means f o r supplying the heating g a s g e n e r a t i o n means
with a p y r o l y s i s gas generated i n the i n d i r e c t - h e a t i n g
20 pyrolysismeansi waste-heat gas generationmeans f o r r e c e i v i n g
supply of p a r t of the heating gas generated i n t h e heating gas
generationmeans a n d g e n e r a t i n g a waste-heat gas by s u b j e c t i n g
the heating gas t o heat exchange; and mixed gas supply m e a n s
f o r supplying the p y r o l y s i s gas supply means with the
25 waztt-heat gas and a luw-ternyeizllu~e l i e d L i 1 1 y y d s y e 1 1 e ~ d L e dw l i e ~ i
the ' h e a t i n g gas heats the coal i n d i r e c t l y i n t h e
i n d i r e c t - h e a t i n g p y r o l y s i s means.
Upgraded coa 1 product i n n equipment according t o a second
aspect of t h e invention for solving t h e above problems is the
30 upgraded coal production cquipmcnt according t o the f i r s t
aspect o f t h e i n v e n t i o n d e s c r i b e d a b o v e , c h a r a c t e r i z e d i n t h a t
the equipment f u r t h e r comprises gas temperature measurement
means, provided a t the p y r o l y s i s gas supply means, f o r
measuring a gas temperature, and the mixed gas supply means
5 includes gas flow r a t e adjustment means f o r a d j u s t i n g a flow
' r a t e of the waste-heat gas and t h e low-temperature heating gas
supplied t o the p y r o l y s i s gas supply means, and c o n t r o l means
for c o n t r o l l i n g the gas flow r a t e adjustment means based on
thegastemperaturemeasuredbythe~astemperaturemeasurement
1 0 means.
EFFECT OF THE IMTENTION
According t o t h e upgraded coal production equipment of
t h e present ~ n v e n t i o n , the low-temperature heating gas and t h e
waste-heat gas canbe s u p p l i e d t o t h e p y r o l y s i s gas supplymeans.
15 Thereby, even i f the p y r o l y s i s gas is cooled i n t h e p y r o l y s i s '
gas stippl y rnpanc, to f a r e pnssihl~ 7 i q i ~ ~ f a r t l n nn r
solidification of t a r ( p y r o l y s i s o i l ) , the low-temperature
hcating gas and the waste heat gas make t h e oxygen
concentration about 1 t o 2 %, and thereby the t a r is o x i d a t i v e l y
zo decomposed. As a r e s u l t , the t a r becomes l l g h t In welght and
is thereby prevented from being attached t o a wall surface of
a duct or the l i k e forming the p y r o l y s i s gas supply means.
Further, since a l i g h t gas generatedwhenthetarbecornes l i g h t
i n weight is combusted, the temperature of t h e p y r o l y s i s gas
25 r i s e s , which can prevent attachment of t a r t o a wall surface
of t h e duct or the l i k e forming t h e p y r o l y s i s gas supply means.
The o x i d a t i v e d e c o m p o s i t i o n o f t h e t a r canbeperformedwlthout
stopping the devlce, and t h e r e f o r e t h e operating r a t e of the
equipment can be improved compared t o equipment which has t o
30 s t o p t h e d e v i c e i n o r d e r f o r t h e t a r t o b e o x i d a t i v e l y d e c o m p o s e d .
In other w o r d s , tar can be removed efflclently. Since the
pyrolysis gas has almost the same temperature as the
low-temperature heating gas a n d t h e waste-heat gas, preheating
of the low-temperature heating gas and the waste-heat gas is
unnecessary, which is energy-saving.
5 BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic diagram showing the overall .
contiguration of amain embodiment of upgraded coal production
equipment according to the present invention.
MODE FOR CARRYING OUT THE INVENTION
10 An embodiment of upgraded coal production equipment
according to the present invention is described.
MAIN EMBODIMENT
Based on Fig. 1, a main embodiment of upgraded coal
production equipment according to the present invention is
15 described.
First, as shown in Fig. 1, low-rank coal 1 such as brown
coal or subbituminous coal is supplied to a drying device 111
by a hopper or the like (not shown), the dryinq device 111 being
drying means for drying the low-rank coal 1. An outlet opening
20 of t.he drying C J P T T ~ C P 111 r n m m l ~ n i c a t ~wsi t h an i n l e t np~ning
122a of a pyrolysis device 121 configuredto perform pyrolysis
o n d r i e d c o a l 2 . A n o u t l e t o p t n i n g 1 2 2 b o f t h e p y r o l y s i s device
121 communicates with an inlet opening of a cooling device 131
being cooling means for cooling pyrolysis coal 3.
The pyrolysis device 121 has an inner cylinder 177 and
an outer cylinder 123 surrounding the inner cylinder 122. The
outer cylinder 123 is supplied with a heating gas 11 to be
described later. Thereby, the dried coal 2 supplied into the ,
inner cylirrder 122 is indirectly heated and is subjected to
7
pyrolysis, to generate the pyrolysis coal 3. In other words,
the pyrolysis device 121 is an indirect-heating device, such
as, e. g., an external heating kiln, in which a hot gas (heating
gas) being a heat source does not come into direct contact with
5 the low-rank coal 1. The pyrolysis device 121 forms
indirect-heating pyrolysis means.
A gas exhaust port of the inner cylinder 122 of the
pyrolysis device 121 communicates with a gas intake port of
a combustion furnace 124 via a pyrolysis gas supply pipe 101.
10 Thereby, a pyrolysis gas 14 containing gaseous tar (pyrolysis
oil) generated by the pyrolysis is supplied to the gas intake
port of the combustion furnace 124. The gas intake port of the
combustion furnace 124 is also supplied with a fuel (not shown)
such as a natural gas. The combustion furnace 124 generates
15 the heating gas 11 by cornbusting the pyrolysis gas 14 and the
fuel such as a natural gas. In other words, thp cornhustinn
furnace 124 forms heating gas generation means. A gas exhaust
port of thc combustion furnace 124 communicates with a gas
intake port of the outer cylinder 123 of the pyrolysis device
20 121 via a heating gas feed pipe 51.
The heating gas feed pipe 51 communicates with a gas
intake port of a steam generator 125 via a heating gas branch
pipe 53. The steam generator 125 forms waste-heat gas
generation means for generating a waste-heat gas 13 through
25 heat exchange between tlie 1-ieatir~yy ds 11 dr~dw d L e ~L U Ll~ereby
generate steam. A gas exhaust port of the steam generator 125
communicates with an exhaust pipe 52 to be described later via
a waste-heat gas feed pipe 54.
A gas exhaust port of the outer cylinder 123 of the
30 pyrolysis dcvice 121 communicates with a gas intake port of
an exhaust-gas treatment device 127 via the exhaust pipe 52, ,
the exhaust-gas treatment device 127 being exhaust-gas
purification means for purifying the waste-heat gas 13 and a
.low-temperature heating gas 12 which is generated when the
5 heating gas 11 heats the inner cylinder 122. The
low-temperature heating gas 12 and the waste-heat gas 13 are
discharged to the outside of the system after undergoing the
purification treatment in the exhaust-gas treatment device
10 The exhaust pipe 52 communicates with a gas intake port
of a blower 126 via a mixed gas feed pipe 55. A gas exhaust
port of the blower 126 communicates with a gas intake port of
tlie ~ u ~ r b u s L i vfr ui rilace 124 v i d a irlixed y d s s u p p l y p i p e 56. Tlie
mixed gas supply pipe 56 communicates with a mixed gas branch
15 pipe 102. The mixed gas branch pipe 102 communicates with a
mixed gas communication pipe 104 via a flow rate adjustment
valve 103. The mixed gas communication pipe 104 communicates
with the pyrolysis gas supply pipe 101.
The pyrolysis gas supply pipe 101 is provided with a gas
20 temperature measurement instrument 105 which is gas
temperature measurement means for measuring the temperature
of a gas inside the pipe. The gas temperature measurement
instrument 105 is connected to a control device 106 such that
the measured gas temperature can be sent to the control device
25 106, the controldevice106beingcontrolmeans for controlling
the valve position of the flow rate adjustment valve 103.
The exhaust pipe 52, the waste-heat gas feed pipe 54,
themixedgas feedpipe 55, theblower126, themixedgas supply
pipe 56, themixedgasbranchpipe102, the flow rate adjustment
30 valve 103, the mixed gas communication pipe 104, and the like
form mixed gas supply means.
In the upgraded coal production equipment according to
?his ~mhndiment thus configured, when the low-rank coal 1 is
charged into the hopper, the hopper supplies the low-rank coal a
5 1 a t n r o o m t c m p c r ~ t u r e t o t h cdr ying device 111 apredetermined
amount at a time. The low-rank coal 1 supplied to the drying
device 111 is removed of water and becomes the dried coal 2
by being heated up to about 200 "C by a drying combustion gas
(about150to 300 O C ) frorna dryingcombustor (not shown). Then,
10 the dried coal 2 is transferred into the inner cylinder 122
of the pyrolysis device 121. The dried coal 2 transferred to
the pyrolysis device 121 is subjected to pyrolysis by being
indirectlyheatedbythe heating gas 11 (gas temperature: about
1050 O C , oxygen concentration: about 2 to 3 % ) from the
15 combustion furnace 124. Thereby, the dried coal 2 becomes the
pyrolysis coal 3 as a result of removal of components such as .
the pyrolysis gas 14 containing gaseous tar, and the pyrolysis
coal 3 is fed t o the cooling device 131. The pyroly~is coal
3 fedtothe coolingdevice131becomes upgradedcoal4 by being
20 cooled down tu about 50 "C.
Meanwhile, the heatinq qas 11 (qas temperature: about
1050 O C , oxygen concentration: about 2 to 3 %) generated in
the c n m h ~ i s tni n f ~ ~ r n a c1e24 is fed t o the outer cylinder 123
of the pyrolysis device 121 via the heating gas feed pipe 51.
25 Thc heating gas 11 usecl inside the outer- cylinder- 123 to heat
the inner cylinder 122 becomesthe low-temperature heating gas
12 (gas temperature: about 350 "C, oxygen concentration: about
2 to 3 % ) . The low-temperature heating gas 12 is fed to the
exhaust pipe 52. Meanwhile, the heating gas 11 is also fed to
30 the steam generator 125 via the heating gas feed pipe 51 and
the heating gas branch pipe 53. The heating gas 11 used in the
steam generator 125 for generation of water vapor becomes the
waste-heat gas 13 (gas temperature: about 350 O C , oxygen
concentration: about 2 to 3 % ) . The waste-heat gas 13 is fed
5 to the exhaust pipe 52 via the waste,-heat gas feed pipe 54.
Part of the low-temperature heating gas 12 and the
waste-heat gas 13 is supplied to the exhaust-gas treatment
device 127. The low-temperature heating gas 12 and the
waste-heat gas 13 undergo the purification treatment in the
10 exhaust-gas treatment device 127 and are then discharged to
the outside of the system. The rest of the low-temperature
heatinggas12 andthewaste-heat gas (gas temperature: about
350 OC, oxygen concentration: about 2 to 3 % ) is fed to the
blower 126 via the mixed gas feed pipe 55.
15 Part of the low-temperature heating gas 12 and the
waste-heat gas .13 fed to the blower 126 is supplied to the
combustion furnace 124 via the mixed gas supply pipe 56. The
rest of the low-temperature heating gas 12 and the waste-heat
gas 13 (gas temperature: about 350 O C , oxygen concentration: ,
20 about2to 3%) fedtothe blower126is suppliedtothepyrolysis
gas supply pipe 101 via the mixed gas branch pipe 102, the flow
rate adjustment valve 103, andthemixedgas communicationpipe
104.
The valve position of the flow rate adjustment valve 103
25 io controlled by the control device 106 based on tlie gas
temperature measured by the gas temperature measurement
instrument 105. For example, the control device LU6 adjusts
the flow rate adjustment valve 103 by opening it to increase
the aperture when the gas temperature measured by the gas
30 temperature measurement instrument 105 is equal to or higher
than 400 "C, and a d j u s t s t h e flow r a t e adjustment valve 103
by narrowing it when the gas temperature exceeds 550 "C.
Thereby, the low-temperature heating gas 12 and the waste-heat
gas 13 (oxygen concentration: about 2 t o 3 % ) a r e mixed with
5 t h e p y r o l y s i s gas 1 4 (gas temperature: about 400 OC, oxygen
concentration: about 0 % ) , and t h i s mixed gas has an oxygen
concentration adju%ted t o about 1 t o 2 %. As a r e s u l t , gaseous
t a r ( p y r o l y s i s o i l ) is o x i d a t i v e l y decomposed (decoking) t o
hecome l i g h t i n weight, and thereby attachment of the t a r t o
10 t h e p y r o l y s i s gas supply pipe 101 can be prevented. The t a r
is reduced in weight to become a light gas, and this light gas
is combusted. Thus, decrease i n the gas temperature is
preverlled. T l i e r e b y , d L L d ~ l 1 1 i l e r i Lu f the tar to the p y r o l y s i s gas
supply pipe 101 can be prevented. S p e c i f i c a l l y , the decoking
15 is performed j u s t when t h e t a r is about t o be attached t o the
inner wall surface of the p y r o l y s i s gas supply pipe 101 by
adjustment of t h e amount of the low-temperature heating gas
1 2 a n d t h e w a s t e - h e a t g a s 1 3 s u p p l i e d t o t h e p y r o l y s i s gas supply
pipe 101 based on the g a s temperature i n s i d e the p y r o l y s i s gas
20 supply pipe 101. Hence, t h e t a r can be e f f i c i e n t l y removed.
Thus, according t o t h e upgraded coal production
equipment according t o t h i s embodiment, by supplying t h e
low-temperature heating gas 12 and the waste-heat gas 13 i n t o .
the p y r o l y s i s gas supply pipe 101, t h e oxygen concentration
25 of t h e gases 12, 13, 1 4 i n t h e p y r o l y s i s gas supply pipe 1 0 1
'is adjusted t o about 1 t o 2 %, so t h a t t a r contained i n the
p y r o l y s i s gas 1 4 ( p y r o l y s i s o i l ) is o x i d a t i v e l y decomposed
[decoking) t o become l i g h t i n weight. Thereby, attachment of
t h e t a r t o t h e p y r o l y s i s gas supply pipe 101 can be prevented.
Moreover, sincealightgasgeneratedwhenthetarbecomes
light in weight is combusted, the temperature of the pyrolysis
gas 14 rises, which can prevent attachment of the pyrolysis
oil to a wall surface of the pyrolysis gas supply pipe 101 and
the like. Since the pyrolysis gas 14 has almost the same
5 temperature as the low-temperature heating gas 12 and the
waste-heat gas 13, preheating of the low-temperature heating
gas 12 and the waste-heat gas 13 is unnecessary, which is
energy-saving. Furthermore, since decoking can be performed
to remove tar without stoppinq the device, the operatinq rate
10 of the equipment can be improved compared to equipment which
has to stop the device to decoke the device for tar removal.
In other words, tar can be removed efficiently.
INDUSTRIAL APPLICABILITY
The upgraded coal production equipment according to the ,
15 present invention can remove tar efficiently without lowering
the production volume of upgraded coal, and can t h ~ r e f o r eh e
utilized significantly beneficially in various industries.
WE CLAIM:
1. Upgraded coal production equipment including
drying means for drying coal,
i n d i r e c t - h e a t i n g p y r o l y s i s means f o r performing
p y r o l y s i s on the dried coal by indirectly heating the
d r i e d coal by use of a heating gas, and
coolingmeans ror c o o l i n g t h e c o a l s u b j e c t e d t o t h e
p y r o l y s i s ,
c h a r a c t e r i z e d i n t h a t the equipment comprises:
hcating gas qcncration rncans for generating the
heating gas;
p y r o l y s i s gas supply means f o r supplying the
heating gas generation means with a p y r o l y s i s gas
g e n e r a t e d . i n t h e i n d i r e c t - h e a t i n g p y r o l y s i s means;
waste-heat gas generation means f o r receiving
s u p p l y o f p a r t o f t h e h e a t i n g g a s g e n e r a t e d i n t h e h e a t i n g
gas generation means and generating a waste-heat gas by
s u b j e c t i n g t h e heating gas t o heat exchange; and
mixed gas supplymeans for s u p p l y i n g t h e p y r o l y s i s
gas supply means with t h e waste-heat gas and a
low-temperature heating gas generated when t h e heating
gas heats t h e c o a l i n d i r e c t l y i n the i n d i r e c t - h e a t i n g
pyrolysis means.
2. The upgraded coalproductionequipmentaccordingto claim
2 5 1, c h a r a c t e r i z e d i n t h a t
the equipment f u r t h e r comprises gas temperature
measurement means, provided a t the p y r o l y s i s gas supply
means, for measuring a gas temperature, and
the mixed gas supply means includes
gas f l o w rate adjustmentmeans f o r a d j u s t i n g a f l o w
rate of the waste-heat gas and the low-temperature
heating gas supplied to the pyrolysis gas supply means,
and
control means for controlling the gas flow rate
adjustment means based on the gas temperature measured
by the gas temperature measurement means.
. D a t e d this 15* day of July 2014