TECHNICAL FIELD
The present invention relates to a method for producing
pyrolized coal in which pyrolized coal is producedbypyrolizing
5 coal, a method for running a blast furnace, and a method for
operating a boiler.
BACKGROUND ART
Raw-material coal (raw coal) contains mercury, and a
10 technique for reducing the mercury content in the raw coal is
studied. For example, Patent Document 1 listed below discloses
amethod forproducinglowmercury coal in which low mercury coal
with low mercury content is produced by subjecting raw coal to
heat treatment at a predetermined temperature on the basis of
15 the mercury emission characteristics in the raw coal which shows
a relationship between a heating temperature of the raw coal and
the mercury emission amount in the raw coal.
PRIOR ART DOCUMENT
20 PATENT DOCUMENT
Patent Document 1: US Patent No. 5,403,365 (for example, see Fig.
3 and the like)
SlBIMARY OF THE INVENTION
25 PROBLEMS TO BE SOLVED BY THE INVENTION
However, Patent Document 1 described above discloses only
the method for producing low mercury coal on the basis of the
mercury emission characteristics of raw coal produced in the
Eagle Butte mine. In a case of producing low mercury coal from
30 raw coal and the like produced in another mine, there is a need
to obtain data on the mercury emission characteristics of this
2
raw coal which are special data obtained through experiments.
Work of obtaining data itself is thus cumbersome and may lead
to an increase of production cost.
5 Moreover, when raw coal is subjected to heat treatment at
a temperature simply set only for the purpose of obtaining low
mercury coal by removing mercury from the raw coal, there is
possibilitythatvolatilematters in the raw coal are excessively
removed and the ignitability of the obtained coal deteriorates.
10
Meanwhile, although high-rank coal (high-quality coal)
among various types of coal is used as blast-furnace injected
coal injected into a tuyere of a blast furnace facility and as
fuel of a boiler, use of low-rank coal (low-quality coal) such
15 as brown coal, subbituminous coal, and bituminous coal which are
cheaper than the high-quality coal is studied. Since the
low-quality coal contains a large amount of moisture and has a
lower calorificvalueperunitweightthanthe high-quality coal,
the low-quality coal is subjected to heat treatment to be dried
20 and pyrolized and is thereby turned into pyrolized coal having
an improved calorific value per unit weight. Since the
low-quality coal also contains mercury, there may be a demand
to reduce the mercury content of the pyrolized coal.
2 5 In view of this, the present invention has been made to
solve the problems described above, and an object thereof is to
provide a method for producing pyrolized coal, a method for
running a blast furnace, and a method for operating a boiler in
which pyrolized coal whose mercury content is reduced with
30 excessive reduction of volatile matter content being suppressed
can be produced without performing cumbersome work.
MEANS FOR SOLVING THE PROBLEMS
A method for producing pyrolized coal of a first aspect
of the invention for solving the problems described above is a
5 method for producing pyrolized coal in which pyrolized coal is
produced by pyrolizing raw-material coal, characterizedin that
the method comprises:
obtaining proximate analysis data and ultimate analysis
data on the raw-material coal;
10 deriving a pyrolizing temperature T of the raw-material
coal from calculation expressed by formula (I), by using a
calorific value A which is one type of the proximate analysis
data or which is obtained from the Dulong's formula on the basis
of the ultimate analysis data, a fuel ratio B which is based on
15 the proximate analysis data, a hydrogen content C relative to
a carbon content which is based on the ultimate analysis data,
and an oxygen content D relative to the carbon content which is
based on the ultimate analysis data; and
setting a temperature at which the raw-material coal is
20 to be pyrolized on the basis of the pyrolizing temperature T of
the raw-material coal,
T = tl+aA+bB+cC+dD ... (1)
where tl is an intercept, a, b, c, and d are coefficients,
and tl, a, b, c, and d satisfy 4501t11475, 0.1451a10.155,
25 -6401bI-610, 16001cg1700, and -5401dI-500, respectively.
A method for running a blast furnace of a second aspect
of the invention for solving the problems described above is
characterized in that pulverized coal produced by pulverizing
30 thepyrolizedcoalproducedinthemethodforproducingpyrolized
coal according to the first aspect is used as blast-furnace
i n j e c t i o n c o a l i n j e c t e d i n t o atuyere ofablast furnace facility.
A method for operating a boiler of a third aspect of the
invention for solving the problems described above is
5 characterized in that the pyrolized coal produced in the method
for producing pyrolized coal according to the first aspect is
used as fuel of a boiler.
EFF%CT OF THE INVENTION
10 In the method for producing pyrolized coal of the present
invention, pyrolized coal whose mercury content is reduced with
excessive reduction of volatile matter content being suppressed
can be produced only by setting the temperature at which the
raw-material coal is to be pyrolized to the pyrolizing
15 temperature T of the raw-material coal obtained by substituting
the calorific value, the fuel ratio, the hydrogen content
relative to the carbon content, and the oxygen content relative
to the carbon content which are obtained from the proximate
analysis data and the ultimate analysis data on the raw-material
20 coal and the Dulong's formula, into the aforementioned formula
(1) . Since the proximate analysis data and the ultimate analysis
data on the raw-material coal are not special data but are the
most basis datausedto show the qualityofthe raw-material coal,
there is no need to perform cumbersome work such as obtaining
25 data on the mercury emission characteristics in the raw-material
coal.
In the method for running a blast furnace and the method
for operating a boiler of the present invention, since the
30 pyrolized coal itself is coal whose mercury content is reduced,
itispossibletogreatlyreducethemercurycontentincombustion
5
exhaust gas generated when the pyrolized coal is combusted.
Moreover, since the pyrolized coal is coal in which excessive
reduction of volatile matter content is suppressed,
deterioration of ignitability of the pyrolized coal can be
5 suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a flowchart showing procedures for setting a
pyrolizing temperature in a method for producing pyrolized coal
10 of the present invention.
Fig. 2 is a flowchart showing procedures in the method for
producing pyrolized coal of the present invention.
15 MODE FOR CARRYING OUT THE INVENTION
The present invention is not limited to the following
embodiment in which a method for producing pyrolized coal, a
method for running a blast furnace, and a method for operating
a boiler of the present invention are described.
20
In the embodiment, specific description is given based on
Figs. 1 and 2.
In the embodiment, as shown in Fig. 2, raw coal 11 which
25 is raw-material coal is dried by being heated (for example, at
110 to 200'~ for 0.1to lhour) in a low-oxygen atmosphere (oxyger,
concentration: equal to or less than 5 volume percent) (drying
step S21) to remove moisture. Thereafter, the coal is pyrolized
by being heated (at a pyrolizing temperature T for 0.1 to 1 hour)
30 in a low-oxygen atmosphere (oxygen concentration: equal to or
less than 2 volume/weight percent) (pyrolizing step S22) to
remove volatile matters (for example, H20, C02, tar, Hg, and the
like) as pyrolysis gas andpyrolysis oil. Then, the coal is cooled
(at a temperature equal to or lower than 50"~)in a low-oxygen
atmosphere (oxygen concentration: equal to or less than 2 volume
5 percent) (cooling step S23), and pyrolized coal 12 is thus
produced.
Here, the pyrolizing temperature T described above is set
based on the following formula (1).
10
T = tl+aA+bB+cC+dD . . . (1)
In the formula, T represents the pyrolizing temperature
("c) , A represents a calorific value (as received basis)
(kcal/kg), B represents a fuel ratio, C represents a hydrogen
15 content (wt%) relative to a carbon content (wt%) (H/C), D
represents an oxygen content (wt%) relative tothe carbon content
(wt%) (O/C), tl represents an intercept (constant), and a, b,
c, and d represent coefficients, respectively.
20 Note that tl, a, b, c, and d are each set within a range
shown in the following table 1.

Specifically, tl satisfies 4501t11475, a satisfies
0.145-
U
-
010
2
C -4
h u m m i d o
01
d
2
0
w . 0
m
w
0 x
4 m
a
o\o
. ? $
0 '.x
w w m
0
. w r - m
0 0 0 0
. I d 1
0
w r - m
- 1 4 1
w r - L C
- 1 4 1
I
-
C O O O O 2 - 0 -
d l d l
0
m r i o o
O I I
0 - 0 -
0
U P Q
i o o o o
0 0 0 0 0
o m 0 0 0
e - 0 -
I
- - t ' U U
ri - ri
a, Id
4 0 a u 5 m 9
0
d
-4 z 5
Id U
L- La- -aad
5 2
U -
m
a ,
a 0
U 8 rn L- a-
-
4
Id o
0
4 . 4
a
Q a
rn =r
a, m
b -
-
ri
0
a , n
a o
5 . 5
CI U
rn -4 8 a
U
.d
d
3
0
0
I
-
-
r-
0
U
r
m
1
m
m
- I I d + J U U + J C I
~ u o m o o o
d r i W W 0
0
m
m
* m d d o O
W ~ ~ O I ~ a , ~ 0 0 0 0 0
a5 5 00 L-O O0 O-0 r n . r i w w i n
o
io
i o o o
~ U - j l O I r i I
~ 9 U U P C , U
m w m
0
I
-
[ T a b l e 51 I Item Pyrolizing temperature T
Test sample 1 (bituminous coal)
Unit
Test sample 2 (subbituminous coal)
(Lower limit of coefficient to upper limit of coefficient)
c 0
Test sample 3 (brown coal)
[ T a b l e 61
Comparative sample 1 (subbituminous coal) 269
Item
Unit
Test sample 1 (bituminous coal)
Test sample 2 (subbituminous coal)
Test sample 3 (brown coal)
Comparative sample 1 (subbituminous coal)
Mercury removal rate
(actual measurement)
%
77 to 90
77 to 85
75 to 97
50
Fuel ratio after pyrolysis
(actual measurement)
-
1.7 to 3.0
1.8 to 2.8
1 to 1.5
1.35
Next, the aforementionedtestsamples 1to 3 werepyrolized
at the pyrolizing temperatures shown in the table 5 above. As
a result, as shown in the table 6, it was confirmed that, in the
5 coal of each of test samples 1to 3, the fuel ratio after pyrolysis
was equal to or lower than 3 and the mercury removal rate was
equal to or higher than 75%. The aforementioned comparative
sample 1 was pyrolized at 269"~as shown in the table 5 above.
As a result, as shown in the table 6, it was found that, although
10 the fuel ratio after pyrolysis was 1.35 being equal to or lower
than 3, the mercury removal rate was 50% and was lower than those
of the test samples 1 to 3.
Accordingly, the following fact was confirmed from the
15 confirmation test I. Pyrolized coal whose mercury content is
reduced with excessive reduction of the volatile matter content
being suppressedcanbe obtainedonlyby: obtainingtheproximate
analysis data and the ultimate analysis data on bituminous coal,
subbituminous coal, and brown coal; and setting the temperature
20 at which the raw coal is to be pyrolized on the basis of the
pyrolizing temperature T derived by using the calorific value
being one type of the proximate analysis data, the fuel ratio
based on the proximate analysis data, the hydrogen content
relative to the carbon content based on the ultimate analysis
25 data, and the oxygen content relative to the carbon content based
on the ultimate analysis data, and by setting tl, a, b, c, and
d in the aforementioned formula (1) to satisfy 4501t11475,
0.1451a10.155, -6401bI-610, 16001~11700, and -5401dI-500,
respectively.
30
Meanwhile, in the comparative sample 1, great reduction
(reduction to a target level) of the mercury content could not
be achieved only by setting the coefficient a in the
aforementioned formula (1) outside the numerical range of a in
the aforementioned embodiment. Accordingly, it is assumedthat,
5 even if the intercept tl and the coefficients b, c, and d in the
aforementioned formula (1) are set outside the numerical ranges
of the intercept tl and the coefficients b, c, and d in the
aforementioned embodiment, it is impossible to obtain the
appropriate pyrolizingtemperature range and greatly reduce the
10 mercury contents as in the comparative sample 1 in which only
the coefficient a was set outside the numerical range.
[Confirmation Test 21
Test 2 was performed to confirm whether the pyrolizing
15 temperature (target value), which is obtained based on the
mercury content and the volatile matter content in the raw coal
inthemethodforproducingpyrolizingcoalofthe aforementioned
embodiment and at which pyrolized coal whose mercury content is
reduced with excessive reduction of the volatile matter content
20 being suppressed can be obtained, is included in the range of
pyrolizing temperature (calculation value) derived from the
calculation of the aforementioned formula (1) by using the
proximate analysis data andtheultimate analysis data. Note that
the intercept tl and the coefficients a, b, c, and d in the
25 aforementioned formula (1) were set to satisfy 4501t11475,
0.1451a10.155, -6401bI-610, 16001~11700, and -5405dI-500,
respectively.
O L n O O O O
L n P O L n O O
m m L n L n w m
a,
M
a,
3
4
2
CI
a, rn
I-I
a
B
-
: @ a ,
9 3
G
d
'"
.$:
4
0
Sr
IL
rl
M 3
U
G d
M 3 . 2
a, a, 3 2
a+ 5>
U d
~ . - ~ m r r n w ~
m : % - " - w w w w
0 L n l N W W W rn
r l 5
4
I-I 9
a, U 8 ;
2
+ J m m - L n m -
~ a v n w b
4 4 4 4 i l 4
€ + € + E + B B € +
a , a , a l a , a , a ,
a a a a a a $ 5 5 5 5 5 m m m m m m
+ J + J U + J Q C I
m m m m m m
m m a , m a , a ,
The test sample A is brown coal. As shown in the table 7
above, it was found that the pyrolizing temperature (target
value) was included in the range of pyrolizing temperature
5 (calculation value) derived from the calculation of the
aforementioned formula (1) by using the proximate analysis data
and the ultimate analysis data.
The test sample B is subbituminous coal. As shown in the
10 table 7 above, it was found that the pyrolizing temperature
(target value) was included in the range of pyrolizing
temperature (calculation value) derived fromthe calculation of
the aforementioned formula (1) by using the proximate analysis
data and the ultimate analysis data.
15
The test sample C is bituminous coal. As shown in the table
7 above, it was found that the pyrolizing temperature (target
value) was included in the range of pyrolizing temperature
(calculation value) derived from the calculation of the
20 aforementioned formula (1) by using the proximate analysis data
and the ultimate analysis data.
The test sample D is bituminous coal different from the
test sample C. As shown in the table 7 above, it was found that
25 the pyrolizing temperature (target value) was included in the
range ofpyrolizingtemperature (calculationvalue) derived from
the calculation of the aforementioned formula (1) by using the
proximate analysis data and the ultimate analysis data.
30 The test sample E is bituminous coal different from the
test samples C and D. As shown in the table 7 above, it was found
2 1
that the pyrolizing temperature (target value) was included in
the range of pyrolizing temperature (calculation value) derived
from the calculation of the aforementioned formula (1) by using
the proximate analysis data and the ultimate analysis data.
5
The test sample F is bituminous coal different from the
test samples C, D, and E. As shown in the table 7 above, it was
foundthatthepyrolizingtemperature (target value) was included
in the range of pyrolizing temperature (calculation value)
10 derived from the calculation of the aforementioned formula (1)
by using the proximate analysis data and the ultimate analysis
data.
Accordingly, the following fact was confirmed from the
15 confirmation test 2. Since the pyrolizing temperature
(calculation value) derived from the calculation of the
aforementioned formula (1) by using the proximate analysis data
and the ultimate analysis data includes the pyrolizing
temperature (target value) which is obtainedbasedonthemercury
20 content and the volatile matter content of the raw coal and at
which pyrolized coal whose mercury content is reduced with
excessive reduction of the volatile matter content being
suppressed can be obtained, pyrolized coal. whose mercury content
is reduced with excessive reduction of the volatile matter
25 content being suppressed can be obtained by pyrolizing the raw
coal at the pyrolizing temperature (calculation value).
INDUSTRIAL APPLICABILITY
30 In the method for producing pyrolized coal, the method for
running a blast furnace, and the method for operating a boiler
sf the present invention, pyrolized coal whose mercury content
is reduced with excessive reduction of the volatile matter
content being suppressed can be produced without performing
cumbersome work. Accordingly, the methods of the present
5 invention can be very useful in the steel industry and the power
generation industry.
WE CLAIM:
1. Amethod forproducingpyrolizedcoalinwhichpyrolizedcoal
is produced by pyrolizing raw-material coal, characterized
5 in that the method comprises:
obtaining proximate analysis data and ultimate
analysis data on the raw-material coal;
deriving a pyrolizing temperature T of the
raw-material coal fromcalculation expressedby formula (I),
10 byusing a calorificvalue Awhichis one type ofthe proximate
analysis data or which is obtained from the Dulong's formula
on the basis of the ultimate analysis data, a fuel ratio B
which is based on the proximate analysis data, a hydrogen
content C relative to a carbon content which is based on the
15 ultimate analysis data, and an oxygen content D relative to
the carbon content which is based on the ultimate analysis
data; and
setting atemperature at which the raw-material coal
is to be pyrolized on the basis ofthe pyrolizingtemperature
20 T of the raw-material coal,
T = tl+aA+bB+cC+dD . . . (1)
where tl is an intercept, a, b, c, and d are
coefficients, and tl, a, b, c, and d satisfy 4501t11475,
0.1451a10.155, -6401bI-610, 16001~11700, and -5401dI-500,
2 5 respectively.
2. A method for running a blast furnace, characterized in that
pulverized coal produced by pulverizing the pyrolized coal
producedinthemethodforproducingpyrolizedcoalaccording
30 to claim 1 is used as blast-furnace injection coal injected
into a tuyere of a blast furnace facility.
3. A method for operating a b o i l e r , characterized i n t h a t the
pyrolizedcoalproducedinthemethodforproducingpyrolized
coal according t o claim 1 is used a s f u e l of a b o i l e r .