DESCRIPTION
METHOD FOR INCREASING COKE-OVEN GAS
Technical Field
The present invention relates a method of increasing the
amount of coke-oven gas, and, more particularly, to a method
of increasing the amount of coke-oven gas by optimizing the
starting point of introduction of steam into a gas way in a.
carbonization chamber of a coke oven and thus increasing the
introduction time of the steam into the gas way.
Background Art
A coke oven is an apparatus for preparing coke by
carbonizing coal (raw material) at high temperature. In the
coke oven, coal is charged in a carbonization chamber, heated
to 1100°C ~ 1340°C and then maintained at the same temperature
for a predetermined time to carbonize the coal. Here, in
order to maintain such a temperature state, air and fuel gas
are supplied into a combustion chamber.
A coke oven is equipped with a plurality of independent
carbonization chambers, and each of the carbonization chambers
is provided with a gas rising pipe.
Such a coke oven generates coke-oven gas (COG), which is

a volatile gas, during the process of carbonizing the coal
stored in each carbonization chamber. This coke-oven gas is
discharged through the gas rising pipe of the coke oven.
The coke-oven gas discharged through the gas rising pipe
of the coke oven includes a large amount of environmental
pollutants, such as dust, tar and the like, together with
volatile materials. In order to remove such environmental
pollutants, generally, they are collected in a gas collection
pipe, and then sent into a post-treatment process.
Meanwhile, coke-oven gas is mostly reused as fuel in an
iron mill by a refining process. With the increase in the
usage of coke-oven gas, methods of increasing the usage of
coke-oven gas have recently been researched and developed;
In relation to such research and development, various
conventional technologies are disclosed.
Japanese Unexamined Patent Application Publication No.
2000-144142 (2000.05.26.) discloses "a method of removing
carbon attached to a carbonization chamber of a coke oven".
This method is a technology of removing carbon attached
to a carbonization chamber of a coke oven by injecting a gas
mixture including carbon dioxide and steam into the
carbonization chamber, and is characterized in that carbon
dioxide (steam) and air is alternately provided in order to
prevent the extreme rise and fall of temperature in the
carbonization chamber at the time of gas injection.

Further, Korean Patent Registration No. 10-1082127
(2011.11.03.)/ filed and registered by the present inventor,
discloses "a method of increasing the amount of coke-oven gas
using carbon dioxide". This method is a technology of
increasing the amount of coke-oven gas by reacting high-
temperature carbon with carbon dioxide and water using the
waste heat generated from a coke oven, and is characterized in
that carbon dioxide, water or a mixture thereof (gasifying
agent) was supplied into a gas way in a carbonization chamber
of a coke oven, and thus the gasifying agent reacts with
carbon in the carbonization chamber, thereby increasing the
amount of coke-oven gas.
The above-mentioned conventional technologies disclose
methods of increasing the amount of coke-oven gas as well as
recovering waste heat from coke-oven gas by injecting carbon
dioxide and water into a coke oven to induce an endothermic
reaction with high-temperature carbon.
However, the present inventor' ascertained that various
problems occurred when the amount of coke-oven gas was
increased by the conventional technologies.
In order to confirm the above problems, the present
inventor made experiments on the change in temperature of a
gas way located at the upper portion of a carbonization
chamber of a coke oven and the change in amount of generation
of coke-oven gas over time, assuming that the operation time

of the coke oven in one cycle is set to 24 hours. The results
thereof are shown in FIG. 1.
As shown in FIG. 1, it can be ascertained that the
temperature of the gas way located at the upper portion of the
carbonization chamber was maintained at 500°C ~ 1100°C and that
the amount of generation of coke-oven gas started to increase
rapidly in about 6 hours, was maximized in about 10 hours, and
decreased rapidly • in about 13.5 hours. These numerical
results may be changed by various factors, such as rate of
temperature increase, structure of a coke oven, amount of
charged raw material, etc., but the forms of generation of
coke-oven gas are similar to each other.
According to this change in amount of generation of coke-
oven gas, carbon dioxide must be introduced when the amount of
generation of coke-oven gas is less than the average amount
thereof. Therefore, when carbon dioxide is introduced
therebefore, there is a problem in that it moves together with
coke-oven gas in the gas way, so the effective residence time
thereof in the gas way is insufficient, and thus the reaction
time thereof with carbon in the gas way is also insufficient.
That is, a predetermined level of residence time can be
secured only when carbon dioxide is introduced in 14 hours,
and an endothermic reaction of carbon dioxide with carbon
attached to a coke oven occurs even when the temperature of

coal charged in the coke oven reaches 800°C or higher.
Therefore, there occurs a problem that a carbonization region,
which can be used at the time of a reaction of carbon dioxide
and carbon, is limited to a predetermined region.
Meanwhile, for the purpose of treating coke-oven gas, a
coke-oven gas treatment system is disposed at the rear end of
a coke oven. Here, when the amount of coke-oven gas is
increased by the introduction of carbon dioxide, a part of
unreacted carbon dioxide is introduced into a hydrogen sulfide
(H2S) removal system to remove H2S, whereas most of unreacted
carbon dioxide is supplied to a subsequent process to remove
combustible components from coke-oven gas, thus lowering
calorific value. Further, in this case, carbon dioxide,
instead of H2S, is removed by the hydrogen sulfide (H2S)
removal system itself, thus lowering H2S removal efficiency.
It is to be understood that the foregoing description is
provided to merely aid the understanding of the present
invention, and does not mean that the present invention falls
under the purview of the related art which was already known
to those skilled in the art.
[Cited references]
(Patent document 1) Japanese Unexamined Patent
Application Publication No. 2000-144142 (2000.05.26.)
(Patent document 2) Korean Patent Registration No. 10-

1082127 (2011.11.03.)
Disclosure
Technical Problem.
Accordingly, the present invention has been made to solve
the above-mentioned problems, and an object of the present
invention is to provide a method of increasing the amount of
coke-oven gas, wherein the amount of generation of coke-oven
gas can be increased by optimizing the starting point of
introduction of steam, the reaction rate of steam with carbon
being higher than the reaction rate of carbon dioxide with
carbon, into a coke oven and thus maximizing the reaction time
of steam with carbon in the coke oven.
Technical Solution
In order to accomplish the above object, an aspect of the
present invention provides a method of increasing an amount of
coke-oven gas, including the step of: introducing, steam into a
gas way of a carbonization chamber of a coke oven such that a
water-gas reaction is conducted at 500°C or higher during a
process of carbonizing coal in the carbonization chamber of
the coke oven, wherein the starting point of introduction of
steam into the gas way is moved up prior to a time point at
which an amount of generation of coke-oven gas is maximized,

so as to increase the steam introduction time, thereby
maximizing a reaction of steam with carbon existing in the
carbonization chamber of the coke oven.
Assuming that carbonization time in the coke oven is 24
hours, steam may be introduced after 2 hours from
carbonization start point.
Tar generated in the early stage of carbonization may be
removed by the following Reaction Formula: Tar + H2O —> CO +
CH4 + H2, and the effective residence time (T ) of steam may be
determined by dividing the effective volume of the gas way by
the total amount of the introduced steam and the generated
coke oven.
The collision frequency of the carbon existing in the
carbonization chamber of the coke oven and the steam
introduced into the gas way may be increased.
The collision frequency of the carbon existing in the
carbonization chamber of the coke oven and the steam
introduced into the gas way may be expressed by a collision
frequency factor (A) , and the collision frequency factor (A)
may be determined in consideration of the structure of the gas
way and the flow of the steam.
The conversion ratio (X) of the introduced steam into
coke-oven gas may be represented by the following Formula:
X = [l-l/(Ae-E/RT* T )]1/n

(E: activation energy (J/mol), R: 8.3144(J/mol*K), T:
reaction temperature (K), n: reaction order).
The amount of introduction of steam may be changed
according to the effective residence time of steam and the
reaction temperature.
The effective residence time of steam may be changed
according to the introduction position of steam and the
introduction manner of steam.
The introduced steam may react with carbon existing in
the carbonization chamber of the coke oven by the following
Formula:
C + H2O —> H2 + CO,
and the relation among the total production (P) of
reducing gas (H2 + CO) , the conversion ratio (X) of steam and
the amount (FH2o) of introduced steam may be represented by the
following Formula:
P = 2 * Σ X * FH2o * t
(P: total reducing gas production (Nm3/min) , FH2o: steam
introduction amount (Nm3/min), t: steam introduction time
(min)).
The relation between the conversion ratio (X) of the
introduced steam into coke-oven gas and the partial pressure
of the steam existing in the carbonization chamber of the coke
oven may be represented by the following Formula:

dX/dt = Ae-E/RT(PH20)n(l-X)
(E: activation energy (J/mol), R: 8.3144(J/mol*K), T:
reaction temperature (K), n: reaction order).
Oxygen may be supplied into the carbonization chamber of
the coke oven before the steam is introduced into the gas way.
The steam may be introduced into the gas way of the
carbonization chamber of the coke oven while it is preheated
by waste heat discharged from a gas rising pipe provided on
the carbonization chamber.
Advantageous Effects
The present invention can exhibit the following
advantages thanks to the above technical configuration.
First, steam introduction time can be increased because
steam can be introduced before the amount of generation of
coke-oven gas in a carbonization chamber of a coke oven is
maximized.
Second, thanks to the increase in steam introduction
time, the amount of generation of coke-oven gas can be
increased several times compared to when a conventional coke
oven using carbon dioxide is used.
Third, tar generated in the early stage of carbonization
reacts with steam to be converted into hydrogen and carbon
monoxide, and thus the burden of a tar removal process can be
reduced.

Fourth, a problem of a H2S removal rate being reduced due
to the introduction of carbon dioxide can be solved.
Fifth, a steam conversion rate can be calculated by using
the residence time of steam in a gas way of a carbonization
chamber of a coke oven.
Sixth, the total production of reducing gas can be
calculated by using the steam conversion rate.
Description of Drawings
FIG. 1 is a graph showing the change in amount of coke-
oven gas generated from a coke oven over time.
FIG. 2 is a schematic view showing a coke oven for
realizing the method of increasing the amount of coke-oven gas
according to the present invention.
FIG. 3 is a graph showing the starting point of
introduction of steam in the method of increasing the amount
of coke-oven gas according to the present invention.
Best Mode
Hereinafter, preferred embodiments of the present
invention will be described in detail with reference to the
accompanying drawings.
As shown in FIG. 2, the method of increasing the amount
of coke-oven gas according to the present invention is carried
out by a coke oven including a carbonization chamber 10, a

combustion chamber (not shown), a coke supply unit 20, a steam
introduction pipe 30 and a gas rising pipe 40. Detailed
descriptions of these constituents will be omitted because
they are the same as those disclosed in Korean Patent
Registration No. 1082127.
However, it is preferred that the steam introduction pipe
30 be disposed at a side of the carbonization chamber 30
provided at the opposite side thereof with the gas rising pipe
40, the side being far away from the opposite side thereof.
That is, the steam introduction pipe 30 is disposed in this
way in order to secure sufficient residence time and
sufficient reaction time while steam moves to the gas rising
pipe 40 through a gas way (W) of the carbonization chamber 10.
The method of increasing the amount of coke-oven gas
according to the present invention is characterized in that
steam is introduced into a gas way of a carbonization chamber
of a coke oven such that a water-gas reaction is conducted at
500°C or higher during a process of carbonizing coal in the
carbonization chamber of the coke oven, so the effective
residence time of steam increases, thereby maximizing the
reaction time of steam with carbon existing in the
carbonization chamber of the coke oven.
When steam is introduced under the condition of lower
than 500°C, thermodynamically, a reaction does not easily take

place.
As above, high-temperature waste heat can be efficiently
recovered by a water-gas reaction corresponding an endothermic
reaction at 500°C or higher, and a carbonization region
capable of introducing steam is enlarged, thus remarkably
increasing the amount of coke-oven gas.
As shown in FIG. 1, when the carbonization time in a coke
oven is set to 24 hours, the temperature of the gas way
located at the upper portion of the carbonization chamber is
maintained at 500°C ~ 1100°C, and the amount of generation of
coke-oven gas starts to increase rapidly in about 6 hours from
the carbonization start point, is maximized in about 10 hours
therefrom, and decreases rapidly in about 13.5 hours
therefrom. These numerical results may be changed by various
factors, such as rate of temperature increase, structure of a
coke oven, amount of charged raw material, etc., but the forms
of generation of coke-oven gas are similar to each other.
According to the pattern of generation of coke-oven gas
over carbonization time, in order to increase the amount of
coke-oven gas by the introduction of carbon dioxide into a
coke oven, sufficient carbon dioxide residence time can be
secured only after the lapse of at least 13.5 hours from
carbonization start point, so there is a problem that the
starting point of introduction of carbon dioxide is limited.

That is, since coke-oven gas generated in a coke oven moves
toward a gas rising pipe through the gas way, when carbon
dioxide is introduced at the carbonization time region in
which the amount of generation of coke-oven gas rapidly
increases, there is a problem that the effect of increasing
the amount of coke-oven gas is reduced in half because the
residence time of carbon dioxide in the coke oven and the
reaction time of carbon dioxide with carbon existing in the
carbonization chamber are very short..
In the method of increasing the amount of coke-oven gas
according to the present invention, steam is introduced into
the gas way in a carbonization chamber of a coke oven before
the amount of coke-oven gas generated in the process of
carbonizing coal in the carbonization chamber of the coke oven
is maximized, so steam introduction time is increased, thus
maximizing the reaction time of steam with carbon existing in
the carbonization chamber of the coke oven and solving the
problem caused by the introduction of carbon dioxide. That
is, the reaction temperature of steam and carbon is lower than
the reaction temperature of carbon dioxide and carbon, and the
reaction rate of steam and carbon is higher than the reaction
rate of carbon dioxide and carbon, thereby advancing the
starting point of introduction of steam.
As shown in FIG. 3, according to the present invention,
assuming that carbonization time in the coke oven is 24 hours,

steam can be introduced after 2 hours from the carbonization
start point, if the temperature in the gas way is 500°C or
higher.
Generally, the temperature in the gas way reaches 500°C ~
1100°C. However, for the reaction of steam with carbon (about
500CC) attached to the inner side of the upper portion of the
carbonization chamber of the coke oven, steam must be
introduced at 500°C or higher.
When the carbonization time is about 2 hours, water
contained in the charged coal is almost volatilized, and thus
the optimal reaction efficiency can be expected according the
introduction of steam. However, when steam is introduced
before 2 hours from the carbonization start point, there is a
problem in that the reaction efficiency is reduced in half
because coal contains water.
Since the reaction rate of steam with carbon is higher
than that of carbon dioxide with carbon, the generation of
coke-oven gas increases rapidly. Therefore, although the flow
rate of coke-oven gas in the gas way increases, steam reacts
with carbon existing in the gas way before it comes out of the
gas way, and thus the starting point of introduction of steam
can be advanced before the generation of coke-oven gas is

maximized.
Further, since the reaction temperature of steam with
carbon is lower than that of carbon dioxide with carbon, steam
can be introduced when the temperature in the gas way is
higher than 500°C.
The present inventor recognized that the reaction of
steam with carbon takes place at low temperature compared to
the reaction of carbon dioxide with carbon and that the
reaction rate of steam with carbon is higher than the reaction
rate of carbon dioxide with carbon by three or more times.
Based on these recognitions, steam was introduced after 2
hours from the carbonization start point, and thus the steam
introduction time, which was two times longer than a
conventional carbon dioxide introduction time, was secured.
Conseguently, it can be ascertained that steam can be
introduced to such a degree that the moles of steam is about
six times those of carbon dioxide.
Further, according to the present invention, tar
generated in the early stage of carbonization reacts with
steam to be converted into hydrogen and carbon monoxide, and
thus the burden of a tar removal process can be reduced.
Tar + H2o —> CO + CH4 + H2
Based on these facts, the present inventor made
experiments on the reactivity of carbon dioxide and steam with

high-temperature carbon according to reaction temperature and
residence time.
The conversion rates of steam and carbon dioxide were
evaluated while changing the reaction temperature in a tester
partially filled with carbon to 800°C and 900°C and changing
the residence time of steam and carbon dioxide in the tester
to 30 seconds and 1 minute.
In this case, nitrogen was used as balance gas for
residence time control, and steam and carbon dioxide were
introduced at a flow rate of G L/hr. The results thereof
(reactivity (conversion rate)) are given in Table 1 below.

As given in Table 1 above, it can be ascertained that the
conversion rate of carbon dioxide is 60% or less under the
conditions of a reaction temperature of lower than 900°C and a
residence time of shorter than 60 seconds. Therefore, there

is a serious problem in treating the remaining carbon dioxide.
In contrast, it can be ascertained that the conversion
rate of steam is about two times that of carbon dioxide at low
temperature and that, considering the temperature of a coke
oven, the introduction time of steam is about two times that
of carbon dioxide. Therefore, it can be ascertained that the
coke-oven gas increment attributable to steam is about four
times the coke-oven gas increment attributable to carbon
dioxide.
Meanwhile, in the method of increasing the amount of
coke-oven gas according to the present invention, the
conversion rate of steam can be improved by maximizing the
effective residence time of steam, this effective residence
time thereof being obtained by dividing the effective volume
of a gas way by the total amount of introduced steam and
generated coke oven gas, and further can be improved by
increasing the collision freguency of the carbon existing in
the carbonization chamber of the coke oven and the steam
introduced into the gas way.
The collision frequency of the carbon existing in the
carbonization chamber of the coke oven and the steam
introduced into the gas way is expressed by a collision
frequency factor (A) , and the collision frequency factor (A)
is an optional value determined by the structure of the gas
way, the flow of steam, the charging of carbon, attaching

structure or the like.
The present inventor found a steam conversion rate and
various factors influencing the steam conversion rate, and
analyzed the relation among these factors, thus deducing the
specific correlation among the above factors. This specific
correlation is represented by the following Formula 1:

wherein X represents a steam conversion rate, and the
range thereof is 0 ~ 1.
T represents effective residence time of steam in a gas
way, and is obtained by dividing the effective volume (Nm3) of
a gas way by the total flow rate (Nm3/sec) of steam and coke-
oven gas. Substantially, this effective residence time of
steam corresponds to the reaction time of steam with carbon in
a coke oven, and its value is 1 ~ 300 seconds.
This effective residence time of steam may be determined
by the introduction position and introduction manner of steam.
A is a collision frequency factor (sec-1) representing the
collision frequency of steam and carbon, and is determined by
the structure of the gas way, the flow of steam, the charging
of carbon, attaching structure or the like. The value thereof
is 102 ~ 108.
E represents activation energy (J/mol) for a reaction of
steam and carbon (compounded coal, attached carbon, sponge

carbon, coke or the like), and its value is 10000 ~ 200000.
R represents an ideal gas constant (J/mol*K), and its
value is 8.3144.
T represents a reaction temperature (K), and its value is
800 ~ 1400.
n represents a reaction order, and its value is 0.5 ~ 1.
n depends on the kind of carbon (compounded coal, attached
carbon, sponge carbon, coke or the like).
As such, the conversion rate of steam can be maximized by
optimizing various factor values using Formula 1 above.
According to Formula 1 above, the efficiency of
increasing the amount of coke-oven gas can be optimized by
changing the amount of introduction of steam according to the
effective residence time of steam and the reaction
temperature.
Meanwhile, the introduced steam reacts with carbon
existing in the carbonization chamber of the coke oven by the
following reaction Formula: C + H2O —> H2 + CO, and the
relation among the total production (P) of reducing gas (H2 +
CO), the conversion ratio (X) of steam and the amount (FH2o) of
introduced steam is represented by the following Formula 2:

(P: total reducing gas production (Nm3/min) , FH2o: steam
introduction amount (NnvVmin) , t: steam introduction time

(min)).
According to Formula 2 above, since the conversion rate
of steam influences the total production- of reducing gas (coke
oven gas), the factors of Formula 1 above influencing the
conversion rate of steam may influence the total production of
reducing gas.
Since the above-mentioned steam conversion rate and steam
introduction amount are changed according to the reaction
temperature range, the total production of reducing gas can be
calculated by adding up all the values corresponding to each
range.

(PH2O: partial pressure of steam in a coke oven, other
factors are the same as those explained in Formula 1 above)
As represented by Formula 3 above, since the conversion
rate of steam can be controlled according to the partial
pressure of steam in the coke oven, t of .Formula 3 above
represents the residence time of steam in a gas way of a coke
oven, and its value is present between 0 and T .
Meanwhile, the method of increasing the amount of coke
oven gas according to the present invention is characterized
in that oxygen is supplied into the carbonization chamber of

the coke oven before the steam is introduced the gas way.
The supplied oxygen reacts with carbon or a carbon
compound to generate carbon dioxide, carbon monoxide, hydrogen
and water. Here, since this reaction is an exothermic
reaction, it prevents the temperature in the gas way of the
carbonization chamber of the coke oven from being lowered.
Further, the temperature of steam introduced into the gas
way of the carbonization chamber of the coke oven must be
maintained constant. Therefore, when water, not steam, is
supplied into the coke oven, the temperature in the
carbonization chamber is lowered, and thus steam, not water,
must be supplied into the coke oven.
The method of increasing the amount of coke oven gas
according to the present invention is further characterized in
that waste heat discharged from a gas rising pipe is
recovered, steam is preheated by this waste heat, and then the
preheated steam is supplied into the gas way of the
carbonization chamber of the coke oven.
For example, when the gas rising pipe is surrounded by a
heat exchange unit (pipe or the like), steam (or water) passes
through the heat exchange unit to absorb the waste heat
discharged from the gas rising pipe and to preheat the steam,
and then the preheated steam is supplied into the gas way in
the carbonization chamber of the coke oven, there are
advantages that the steam having constant temperature can be

easily supplied and the waste heat discharged from the gas
rising pipe can be efficiently recovered.
Although the preferred embodiments of the present
invention have been disclosed for illustrative purposes, those
skilled in the art will appreciate that various modifications,
additions and substitutions are possible, without departing
from the scope and spirit of the invention as disclosed in the
accompanying claims.
[Reference Numerals]
10: carbonization chamber
20: coke supply unit
30: steam introduction pipe
40: gas rising pipe
W: gas way

CLAIMS
1. A method of increasing an amount of coke-oven gas,
comprising the step of:
introducing steam into a gas way of a carbonization
chamber of a coke oven such that a water-gas reaction is
conducted at 500°C or higher during a process of carbonizing
coal in the carbonization chamber of the coke oven,
wherein a starting point of introduction of steam into
the gas way is moved up prior to a time point at which an
amount of generation of coke-oven gas is maximized, so as to
increase the steam introduction time, thereby maximizing' a
reaction of steam with carbon existing in the carbonization
chamber of the coke oven.
2. The method of claim 1, wherein, assuming that
carbonization time in the coke oven is 24 hours, steam is
introduced after 2 hours from carbonization start point.
3. The method of claim 2, wherein tar generated in the
early stage of carbonization is removed by the following
Reaction Formula: Tar + H2O —> CO + CH4 + H2, and the
effective residence time (T ) of steam is determined by
dividing the effective volume of the gas way by the total

amount of the introduced steam and the generated coke oven.
4. The method of claim 1, wherein the collision frequency
of the carbon existing in the carbonization chamber of the
coke oven and the steam introduced into the gas way is
increased.
5. The method of claim 4, wherein the collision frequency
of the carbon existing in the carbonization chamber of the
coke oven and the steam introduced into the gas way is
expressed by a collision frequency factor (A), and the
collision frequency factor (A) is determined in consideration
of the structure of the gas way and the flow of the steam.
6. The method of claim 4, wherein the conversion ratio
(X) of the introduced steam into coke-oven gas is represented
by the following Formula:
X = [l-l/(Ae-E/RT* T )]1/n
(E: activation energy (J/mol), R: 8.3144(J/mol*K), T:
reaction temperature (K), n: reaction order).
7. The method of claim 6, wherein the amount of
introduction of steam is changed according to the effective
residence time of steam and the reaction temperature.

8. The method of claim 6, wherein the effective residence
time of steam is changed according to the introduction
position of steam and the introduction manner of steam.
9. The method of claim 5, wherein the introduced steam
reacts with carbon existing in the carbonization chamber of
the coke oven by the following Reaction Formula:
C + H2O —> H2 + CO, and
the relation among the total production (P) of reducing
gas (H2 + CO) , the conversion ratio (X) of steam and the
amount (FH2o) of introduced steam is represented by the
following Formula:
P = 2 * Σ X * FH20 * t
(P: total reducing gas production (Nm3/min) , FH2o: steam
introduction amount (Nm3/min), t: steam introduction time
(min)).
10. The method of claim 4, wherein the relation between
the conversion ratio (X) of the introduced steam into coke-
oven gas and the partial pressure of the steam existing in the
carbonization chamber of the coke oven is represented by the
following Formula:
dX/dt = Ae-E/RT(PH2o)n(1-X)

(E: activation energy (J/mol), R: 8.3144(J/mol*K), T:
reaction temperature (K) , n: reaction order)..
11. The method of claim 1, wherein oxygen is supplied
into the carbonization chamber of the coke oven before the
steam is introduced into the gas way.
12. The method of claim 1, wherein the steam is
introduced. into the gas way of the carbonization chamber of
the coke oven while it is preheated by waste heat discharged
from a gas rising pipe provided on the carbonization chamber.