TITLE OF THE INVENTION
APPARATUS FOR PRODUCING A COMPOSITE GAS INCLUDING CARBON
MONOXIDE AND HYDROGEN, AND METHOD THEREFOR
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent
Application No. 10-201 1-0090306 filed in the Korean Intellectual Property Office
on September 6, 201 I, the entire contents of which are incorporated herein by
reference.
10
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an apparatus for producing a synthetic
gas, and more particularly, to an apparatus for producing a synthetic gas
15 containing carbon monoxide and hydrogen by using ironmaking process gas.
(b) Description of the Related Art
Currently, molten ironmaking processes carried out in an integrated
steel mill mainly depend on a blast furnace method, and in most cases, the CO
gas generated from coal has been used as a reducing agent for iron ore.
20 Meanwhile, the integrated ironmaking process causes various kinds of
byproduct gasses containing CH JCOIH2, which are mainly used in a heater for
producing steel products, in a power plant for power generation, and the like.
The used ironmaking byproduct gas is discharged from the iron mill as a waste
gas containing a large amount of C02.
+%
Currently, the integrated iron mill generates a large amount of C02 from
a molten ironmaking process, a heating process for producing steel products, or
a power generating process for supplying necessary power. For example, the
production of one ton of steel products results in about 2.18 tons of carbon
5 dioxide (C02).
Currently, in spite of the effort to improve process efficiency, including
reducing the cost of a reducing agent for producing molten iron in order to
reduce the C02 generation in the ironmaking process, the process efficiency in
the integrated ironmaking process based on a blast furnace has already
lo reached its limits, with the result that it is very difficult to further reduce C02.
The above information disclosed in this Background section is only for
enhancement of understanding of the background of the invention and therefore
it may contain information that does not form the prior art that is already known
in this country to a person of ordinary skill in the art.
15 SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide a method
for producing a synthetic gas containing carbon monoxide (CO) and hydrogen
(Hz) by allowing carbon dioxide generated from an integrated ironmaking
process to react with methane.
20 [Technical Solution1
An exemplary embodiment of the present invention provides an
apparatus for producing a synthetic gas containing carbon monoxide and
hydrogen, the apparatus including: a first pre-treating unit for pre-treating a
methane-containing ironmaking byproduct gas; a second pre-treating unit
*3
spaced apart from the first pre-treating unit and pre-treating a carbon dioxidecontaining
ironmaking byproduct gas; a steam generating unit for supplying
steam to a mixed gas in which the methane-containing ironmaking byproduct
gas treated by the first pre-treating unit and the carbon dioxide-containing
5 ironmaking byproduct gas treated by the second pre-treating unit are mixed;
and a reforming reaction unit for receiving the mixed gas to which the steam is
supplied and reforming the mixed gas into a gas containing carbon monoxide
and hydrogen.
The methane-containing ironmaking byproduct gas may be a coke oven
lo gas (COG).
The carbon dioxide-containing ironmaking byproduct gas may be at
least one selected from an off-gas from a blast furnace, an off-gas from a
fluidized reduction furnace in a FINEX process, an off-gas from a power
generator in an ironworks, an off-gas from a heating furnace for producing steel
15 products, and an off-gas from a coke oven heating furnace.
The carbon dioxide-containing ironmaking byproduct gas may further
contain an off-gas exhausted from the reforming reaction unit.
The steam generating unit may receive heat from the off-gas exhausted
from the reforming reaction unit.
The first pre-treating unit may include: a first storage chamber for storing
the methane-containing ironmaking byproduct gas; and a refiner for refining the
methane-containing ironmaking byproduct gas exhausted from the first storage
chamber.
The first pre-treating unit may further include: a liquefied natural gas
ect
(LNG) injecting conduit for additionally supplying methane to the methanecontaining
ironmaking byproduct gas exhausted from the first storage chamber;
and a desulfurizer for removing sulfur from the liquefied natural gas.
The second pre-treating unit may include: a second storage chamber for
5 storing the carbon dioxide-containing ironmaking byproduct gas; and a refiner
for refining the carbon dioxide-containing ironmaking byproduct gas exhausted
from the second storage chamber.
The second pre-treating unit may further include a carbon dioxide
separator for separating carbon dioxide from some or all of the refined carbon
10 dioxide-containing ironmaking byproduct gas.
The carbon dioxide separator may receive heat from the off-gas
exhausted from the reforming reaction unit.
The apparatus may further include a pressure boosting unit for boosting
a pressure of the mixed gas in which the methane-containing ironmaking
15 byproduct gas and the carbon dioxide-containing ironmaking byproduct gas are
mixed.
The apparatus may further include a temperature raising unit for raising
a temperature of the pressure-boosted mixed gas so as to be appropriate for a
reaction temperature in the reforming reaction unit.
The temperature raising unit may receive heat from the off-gas
exhausted from the reforming reaction unit.
The apparatus may further include a hydrogen preparing unit for
preparing hydrogen from some or all of a carbon monoxide-containing reducing
gas prepared by reforming the mixed gas in the reforming reaction unit.
+5
The hydrogen preparing unit may further include: a water-gas shift
reactor for amplifying a hydrogen content of the carbon monoxide-containing
reducing gas; and a hydrogen separator for separating hydrogen from the
hydrogen-amplified carbon monoxide-containing reducing gas.
5 The hydrogen preparing unit may further include a heat recovery device
for cooling the reformed carbon monoxide-containing reducing gas.
The water-gas shift reactor may receive steam from the steam
generating unit.
Some of the hydrogen separated by the hydrogen separator may be
10 mixed with the synthetic gas containing carbon monoxide and hydrogen, which
is reformed by the reforming reaction unit.
The carbon dioxide-containing off-gas exhausted from the hydrogen
separator may be mixed with the carbon dioxide-containing ironmaking
byproduct gas.
15 A mole ratio of methane, carbon dioxide, and steam in the mixed gas
supplied to the reforming reaction unit may satisfy 0 S H201C02 5 5 and 0.1 2
(H2O+CO2)ICH4 S 5.
Another embodiment of the present invention provides an iron ore
reducing system, the system being configured to supply the synthetic gas
20 containing carbon monoxide and hydrogen, which is produced by the apparatus,
to an iron ore reducing unit to thereby reduce iron ore.
The iron ore reducing unit may be a blast fumace or a fluidized
reduction furnace in a FINEX process.
Yet another embodiment of the present invention provides a method for
a6
producing a synthetic gas containing carbon monoxide and hydrogen, the
method including: pre-treating a methane-containing ironmaking byproduct gas;
pre-treating a carbon dioxide-contai ning ironmaking byproduct gas; mixing the
pre-treated methane-containing ironmaking byproduct gas and the pre-treated
5 carbon dioxide-containing ironmaking byproduct gas to generate a mixed gas
and then boosting a pressure of the mixed gas to a predetermined pressure;
raising a temperature of the pressure-boosted mixed gas to a predetermined
temperature; and supplying the temperature-raised mixed gas to a reforming
reaction unit to thereby reform the mixed gas into a carbon monoxide-containing
lo reducing gas.
The pre-heating of the methane-containing ironmaking byproduct gas
may include refining the methane-containing ironmaking byproduct gas, and
mixing the refined methane-containing ironmaking byproduct gas with liquefied
natural gas (LNG).
15 The methane-containing ironmaking byproduct gas may be a coke oven
gas (COG).
The pre-heating of the carbon dioxide-containing ironmaking byproduct
gas may include: refining a carbon dioxide-containing ironmaking byproduct
gas; and separating carbon dioxide from some or all of the refined carbon
20 dioxide-containing ironmaking byproduct gas.
The carbon dioxide-containing ironmaking byproduct gas may be at
least one selected from an off-gas from a blast furnace, an off-gas from a
fluidized reduction furnace in a FlNEX process, an off-gas from a power
generator in an ironworks, an off-gas from a heating fumace for producing steel
G7
products, and an off-gas from a coke oven heating furnace.
The carbon dioxide-containing ironmaking byproduct gas may further
include an off-gas exhausted from the reforming reaction unit.
The method may further include supplying steam to the temperatures
raised mixed gas.
The method may further include preparing hydrogen from some or all of
the reformed carbon monoxide-containing reducing gas.
The preparing of the hydrogen may include: cooling the carbon
monoxide-containing reducing gas; water-gas shift converting the cooled carbon
lo monoxide-containing reducing gas; and separating hydrogen from the watergas
shift converted reducing gas.
The prepared hydrogen may be mixed with the reformed gas.
Yet another embodiment of the present invention provides a method for
reducing iron ore by supplying the synthetic gas containing carbon monoxide
15 and hydrogen, which is produced by the above method, to an iron ore reducing
unit to reduce iron ore.
The iron ore reducing unit may be a blast furnace or a fluidized
reduction furnace in a FlNEX process.
[Advantageous Effects]
According to an embodiment of the present invention, carbon dioxide
generated in the integrated ironmaking process is allowed to react with methane
to thereby produce a synthetic gas containing carbon monoxide (CO) and
methane (H2), which is then used to reduce iron ore or produce dimethylether
(DME) or the like, so that the amount of carbon dioxide generated in the
+g
ironworks can be significantly reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an apparatus for producing a
synthetic gas containing carbon monoxide and hydrogen using an ironmaking
5 process gas according to an exemplary embodiment of the present invention;
FIG. 2 is a flowchart illustrating a process for producing a synthetic gas
containing carbon monoxide and hydrogen using an ironmaking process gas
according to an.exemplary embodiment of the present invention; and
FIG. 3 is schematic diagram showing an apparatus for producing a
lo synthetic gas containing carbon monoxide and hydrogen using an ironmaking
process gas according to another exemplary embodiment of the present
invention.
DETAILED DESCRlPTlON OF THE EMBODIMENTS
Advantages and features of the present invention and methods of
15 accomplishing the same may be understood more readily by reference to the
following detailed description of embodiments and the accompanying drawings.
However, the present invention may be embodied in many different forms, and
should not be construed as being limited to the embodiments set forth herein.
Rather, these embodiments are provided so that this disclosure will be thorough
20 and complete and will fully convey the concept of the invention to those skilled
in the art, and the present invention will only be defined by the appended claims.
Like reference numerals refer to like elements throughout the specification.
Hereinafter, an apparatus for producing a synthetic gas containing
carbon monoxide and hydrogen using an ironmaking process gas according to
%'7
an exemplary embodiment of the present invention will be described with
reference to the accompanying drawings. I in describing the present invention,
detailed descriptions of known functions and constitutions that may obscure the
gist of the present invention will be omitted.
5 FIG. 1 is a schematic diagram showing an apparatus for producing a
synthetic gas containing carbon monoxide and hydrogen using an ironmaking
process gas according to an exemplary embodiment of the present invention.
An apparatus for producing a synthetic gas containing carbon monoxide
and hydrogen using an ironmaking process gas according to an exemplary
lo embodiment of the present invention includes a first pre-treating unit 10 for pretreating
a methane-containing ironmaking byproduct gas, a second pre-treating
unit 20 spaced apart from the first pre-treating unit 10 and pre-treating a carbon
dioxide-containing ironmaking byproduct gas, a steam generating unit 30 for
supplying steam to a mixed gas of which the methane-containing ironmaking
15 byproduct gas treated by the first pre-treating unit 10 and the carbon dioxidecontaining
ironmaking byproduct gas treated by the second pre-treating unit 10
are mixed, a reforming reaction unit 40 for receiving the mixed gas to which the
steam is supplied and reforming the mixed gas into a carbon monoxidecontaining
reducing gas, and an iron ore reducing unit 50 for reducing iron ore
zo by using the carbon monoxide-containing reducing gas.
The first pre-treating unit 10 includes a first storage chamber 13 for
storing the methane-containing ironmaking byproduct gas, and a refiner 15 for
refining the methane-containing ironmaking byproduct gas exhausted from the
first storage chamber 13. The methane-containing ironmaking byproduct gas
4-10
may be supplied directly through a gas conduit without the first storage chamber
13.
In addition, the first pre-treating unit 10 may further include a liquefied
natural gas (LNG) injecting conduit 17 for additionally supplying methane to the
5 methane-containing ironmaking byproduct gas exhausted from the first storage
chamber 13, and a desulfurizer 19 for removing sulfur from the liquefied natural
gas.
The methane-containing ironmaking byproduct gas contains a byproduct
gas having a large amount of methane (CH4), such as a coke oven gas (COG),
lo in the integrated ironmaking process. The coke oven gas includes hydrogen,
carbon monoxide, carbon dioxide, nitrogen, tar, and the like, besides methane.
The byproduct gas includes tar, sulfur, dust, and the like, which may be
poisonous substances to a catalyst in the reforming reaction unit 40, which will
be described later, and thus is removed through an appropriate refiner 15.
15 The byproduct gas may be refined by using dry-type dust collection,
wet-type dust collection, cyclone filtering, H2S control, BTX control, and the like.
Meanwhile, in order to increase the generation amount of the reducing
gas prepared by reforming the methane-containing ironmaking byproduct gas
and the proportion of reducible gas components (CO or H2) in the reducing gas,
20 methane-containing gas supplied from the outside, for example, liquefied
natural gas (LNG), may be additionally mixed with the refined methanecontaining
ironmaking byproduct gas.
The mixture ratio between the liquefied natural gas (LNG) supplied from
the outside and the methane-containing byproduct gas may be determined in
m 11
consideration of supply and demand situations of the byproduct gas generated
in the ironworks and supply and demand situations of the liquefied natural gas.
Therefore, the proportion of the byproduct gas from the ironworks may be
100 % or the proportion of the liquefied natural gas may be 100 %.
5 In the case where the liquefied natural gas is supplied, the desulfurizer
19 may be further provided to remove sulfur contained in the liquefied natural
gas.
The second pre-treating unit 20 includes a second storage chamber 23
for storing the carbon dioxide-containing ironmaking byproduct gas, and a
10 refiner 25 for refining the carbon dioxide-containing ironmaking byproduct gas
exhausted from the second storage chamber 23. The carbon dioxidecontaining
ironmaking byproduct gas may be supplied directly through a pipe
without being stored in the second storage chamber 23.
The carbon dioxide-containing ironmaking byproduct gas may include
15 an off-gas from a blast furnace, an off-gas from a fluidized reduction furnace in
a FINEX process, an off-gas from a power generator in an ironworks, an off-gas
from a heating furnace for producing steel products, and an off-gas from a coke
oven heating furnace.
The carbon dioxide-containing ironmaking byproduct gas is subject to an
20 appropriate refining process to thereby remove tar, sulfur, dust, and the like,
which may be poisonous substances to a catalyst in the reforming reaction unit
40.
In addition, when the refined carbon dioxide-containing byproduct gas
has a lot of inert gas, such as nitrogen, which is not involved in a reducing
fi[G
reaction of iron ore, the concentrations of reducible gas components (CO and
HZ) in the reducing gas reformed by the reforming reaction unit 40, which will be
described later, is reduced and the reforming reaction unit 40 consumes greater
than necessary amount of energy. Therefore, carbon dioxide is separated
5 from some or all of the refined carbon dioxide-containing byproduct gas by
using a carbon dioxide separator 27 employing an absorption method, a
pressure swing adsorption (PSA) method, a membrane method, or the like,
followed by mixing with the carbon dioxide-containing byproduct gas, so that the
concentration of the inert gas can be reduced.
10 Meanwhile, when carbon dioxide is separated by employing the
absorption method using an absorption liquid such as an amine, ammonia, or
the like, heat is needed to regenerate the absorption liquid. The heat may be
received from a high-temperature off-gas generated from the reforming reaction
unit 40, through appropriate heat exchange.
15 After the refined methane-containing ironmaking byproduct gas and
carbon dioxide-containing ironmaking byproduct gas are mixed to generate a
mixed gas, the pressure thereof may be boosted to 3 to 10 Bar, which is an
operating pressure of the iron ore reducing unit 50, for example, a blast furnace
or a fluidized reduction furnace in the FlNEX process, by using a compressor.
The temperature of the pressure-boosted mixed gas is raised to
600-1000 "C, which is a reaction temperature in the reforming reaction unit 40,
which will be later described, by using a heater and a heat exchanger. In this
case, some or all of the heat necessary for raising the temperature may be
received from a high-temperature off-gas generated from the reforming reaction
* (3
unit 40, through appropriate heat exchange.
Meanwhile, after the pressure and temperature of the mixed gas of the
methane-containing ironmaking byproduct gas and the carbon dioxidecontaining
ironmaking byproduct gas are increased, steam generated by a
5 steam generator may be partially mixed therewith. The mixing of the steam
with the mixed gas in which methane and carbon dioxide are mixed can reduce
sedimentation of carbon in the catalyst layer, which occurs in the reforming
reaction unit 40, and increase the generation amount of hydrogen at the time of
a reforming reaction.
10 Some or all of the heat necessary for generating the steam may be
received from a high-temperature off-gas generated from the reforming reaction
unit 40, through appropriate heat exchange.
The mole ratio of methane, carbon dioxide, and steam supplied to the
reforming reaction unit 40 is preferably not smaller than 0 but not greater than 5
15 for H201C02, and preferably not smaller than 0.1 but not greater than 5 for
(H20+C02)ICH4.
Here, the reason why the mole ratio of steam and carbon dioxide,
H201C02, is limited to the above range is that it is more advantageous to induce
the reaction of methane and carbon dioxide with only carbon dioxide (C02)
20 without supplying the steam (H20) in view of reutilization of carbon dioxide
(C02). That is, it is preferable that the ratio of H201C02 equals 0.
However, the induction of the reaction by using only CHdC02 causes
severe sedimentation of carbon in the catalyst layer, resulting in adversely
affecting operation of the reactor. In this case, it is advantageous to feed
= (9
moisture in order to prevent the sedimentation of carbon.
In addition, if the ratio of H201C02 is increased to 5 or less, the
sedimentation of carbon in the catalyst layer can be sufficiently prevented.
However, if greater than 5, the effect of preventing the sedimentation of carbon
5 reaches its saturation point.
Meanwhile, with respect to the ratio of (H20+C02)ICH4, generally, the
higher the proportion of the steam (H20) and carbon dioxide (C02) reacting with
methane (CH,), the higher the conversion ratio of methane (CH4). However, if
the proportion of the steam (H20) and carbon dioxide (C02) is excessively high
lo as compared with the methane (CH4), the process efficiency and the operating
cost are excessively increased. Therefore, it is preferable that the ratio of
(H20+C02)ICH4is not smaller than 0.1 but not greater than 5.
Here, main reforming reactions in the reforming reaction unit 40 are as
shown in the following Reaction Equations (I) and (2).
CH4+ C0242CO+ 2H2 . . - - (I)
CH4 + H20 CO + 3H2 -..- (2)
Since carbon dioxide generated in the ironworks is regenerated to
carbon monoxide through Reaction Equation (11, and is then able to be reused
as a reducing agent, the amount of carbon dioxide generated in the ironworks
20 can be significantly reduced.
Since the reforming reactions of Reaction Equations (1) and (2) above
are endothermic reactions, heat necessary for the reactions may be supplied by
combustion of fuel in an external jacket of the reactor. The high-temperature
off-gas generated here is exhausted out of the reactor, and then may be used to
M I S
provide heat necessary for operating the steam generator, increasing the
temperature the mixed gas, and separating carbon dioxide.
A fixed bed or fluidized bed reactor may be used as the reforming
reaction unit 40. In the fixed bed reactor, a reforming catalyst is disposed to fill
5 an inside of the reactor. In the fluidized bed reactor, a reforming reaction
occurs while a catalyst fluids moves inside the reactor.
As the catalyst in the reforming reaction unit, a platinum- or nickel-based
material may be used.
The reformed reducing gas generated in the reforming reaction unit 400
lo maintains a pressure of 3-10 Bar and a temperature of 600-1000 "C, and thus
can be used as a reducing gas in the blast or fluidized reduction furnace without
additional units.
A hydrogen preparing unit 80 may further include a water-gas shift
reactor 83 for amplifying a hydrogen content of the carbon monoxide-containing
15 reducing gas, and a hydrogen separator 85 for separating hydrogen from the
hydrogen-amplified carbon monoxide-containing reducing gas.
More specifically, after some of the reformed reducing gas is cooled to
200-450 "C by a heat recovery device 81, the hydrogen content in the reducing
gas is amplified by using the water-gas shift reactor 83, and then hydrogen is
20 separated therefrom by the hydrogen separator 85 employing a pressure swing
adsorption (PSA) method, a membrane method, or the like.
The steam generated from the steam generating unit may be supplied to
the water-gas shift reactor 83 to amplify the hydrogen content.
In the water-gas shift reactor 83, carbon monoxide in the reducing gas
* (6
reacts with the steam to generate hydrogen and carbon dioxide, as shown in
Reaction Equation (3) below.
CO + H20 4 H2+C02 (3)
The separated hydrogen gas may be supplied to external hydrogen
5 markets, or mixed with the reformed reducing gas to increase the hydrogen
content in the reducing gas.
When a reducing gas containing a large amount of hydrogen is used in
a blast furnace or a fluidized reduction furnace in a FlNEX process, the rate of
reducing iron ore can be improved due to the hydrogen, and thus the production
lo rates of molten iron and reduced iron can be improved.
Here, a carbon dioxide-containing off-gas generated from the hydrogen
separator 85 may be used to generate the reformed reducing gas while being
mixed with the carbon dioxide-containing ironmaking byproduct gas.
FIG. 2 is a flowchart illustrating a process for producing a synthetic gas
15 containing carbon monoxide and hydrogen using an ironmaking process gas
according to an exemplary embodiment of the present invention.
A method for producing a synthetic gas containing carbon monoxide and
hydrogen according to an exemplary embodiment of the present invention
includes pretreating a methane-containing ironmaking byproduct gas, pre-
20 treating a carbon dioxide-containing ironmaking byproduct gas, mixing the pretreated
methane-containing ironmaking byproduct gas and the pre-treated
carbon dioxide-containing ironmaking byproduct gas to generate a mixed gas,
and then boosting a pressure of the mixed gas to a predetermined pressure,
raising a temperature of the pressure-boosted mixed gas to a predetermined
s t 7
temperature, and supplying the temperature-raised mixed gas to the reforming
reaction unit 40 to thereby reform the mixed gas into a gas containing carbon
monoxide and hydrogen.
The pre-heating of the methane-containing ironmaking byproduct gas
5 includes refining the methane-containing ironmaking byproduct gas, and mixing
the refined methane-containing ironmaking byprod uct gas with liquefied natural
gas (LNG).
The methane-containing ironmaking byproduct gas is characterized by
being a coke oven gas (COG).
10 Here, the pre-heating of the carban dioxide-cantaining ironmaking
byproduct gas includes refining a carbon dioxide-contai ning ironmaking
byproduct gas, and separating carbon dioxide from some or all of the refined
carbon dioxide-containing ironmaki ng byproduct gas.
The carbon dioxide-containing ironmaking byproduct gas is
15 characterized by being at least one selected from an off-gas from a blast
furnace, an off-gas from a fluidized reduction furnace in a FINEX process, an
off-gas from a power generator in an ironworks, an off-gas from a heating
furnace for producing steel products, and an off-gas from a coke oven heating
furnace.
The carbon dioxide-containing ironmaking byproduct gas may further
contain an off-gas exhausted from the reforming reaction unit.
The method for producing a synthetic gas containing carbon monoxide
and hydrogen further includes supplying steam to the temperature-raised mixed
gas.
Y? M
In addition, the method for producing a synthetic gas containing carbon
monoxide and hydrogen further includes preparing hydrogen from some or all of
the reformed carbon monoxide-containing reducing gas.
The preparing of the hydrogen includes cooling the carbon monoxide-
5 containing reducing gas, water-gas shift converting the cooled carbon
monoxide-containing reducing gas, and separating hydrogen from the watergas
shift converted reducing gas.
The synthetic gas containing carbon monoxide and hydrogen may be
used as a reducing gas for reducing iron ore or preparing dimethylether (DME).
10 FIG. 3 is schematic diagram showing an iron ore reducing system for
reducing iron ore by using the synthetic gas containing carbon monoxide and
hydrogen produced by using an ironmaking process gas according to an
exemplary embodiment of the present invention.
According to a method for reducing iron ore according to an exemplary
15 embodiment of the present invention, the synthetic gas containing carbon
monoxide and hydrogen, produced by the method for producing a synthetic gas,
is supplied to an iron ore reducing unit to thereby reduce the iron ore.
In addition, the iron ore reducing unit is characterized by being a blast
furnace or a fluidized redudon furnace in a FlNEX process.
In the above, although the embodiments of the present invention have
been described with reference to the accompanying drawings, a person skilled
in the art to which the present invention pertains should comprehend that the
present invention can be embodied in other specific forms without departing
from the technical spirit or essential characteristics thereof.
*r?
Thus, the embodiments described above should be construed as being
exemplified and not limiting the present disclosure-The scope of the present
invention is indicated by claims rather than detailed descriptions above, and all
changes and modifications from the meaning, range, and equivalent concept of
5 the claims should be construed as being included in the present disclosure.
While this invention has been described in connection with what is
presently considered to be practical exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed embodiments, but,
on the contrary, is intended to cover various modifications and equivalent
10 arrangements included within the spirit and scope of the appended claims.
WHAT IS CLAIMED IS:
1. An apparatus for producing a synthetic gas containing carbon
monoxide and hydrogen, the apparatus comprising:
5 a first pre-treating unit for pre-treating a methane-containing ironmaking
byproduct gas;
a second pre-treating unit spaced apart from the first pre-treating unit
and pre-treating a carbon dioxide-containing ironmaking byproduct gas;
a steam generating unit for supplying steam to a mixed gas in which the
i
10 methane-containing ironmaking byproduct gas treated by the first pre-treating
unit and the carbon dioxide-containing ironmaking byproduct gas treated by the
second pre-treating unit are mixed; and
a reforming reaction unit for receiving the mixed gas to which the steam
is supplied and reforming the mixed gas into a gas containing carbon monoxide
15 and hydrogen.
2. The apparatus of claim 1, wherein the methane-containing
ironmaking byproduct gas is a coke oven g a s ' ( ~ 0 ~ ) .
3. The apparatus of claim 1, wherein the carbon dioxide-containing
ironmaking byproduct gas is at least one selected from an off-gas from a blast
furnace, an off-gas from a fluidized reduction furnace in a FINEX process, an
off-gas from a power generator in an ironworks, an off-gas from a heating
furnace for producing steel products, and an off-gas from a coke oven heating
~ L I
furnace.
4. The apparatus of claim 3, wherein the carbon dioxide-containing
ironmaking byproduct gas further contains an off-gas exhausted from the
s reforming reaction unit.
5. The apparatus of claim 1, wherein the steam generating unit
receives heat from the off-gas exhausted from the reforming reaction unit.
6. The apparatus of claim 1, wherein the first pretreating unit
comprises:
a first storage chamber for storing the methane-containing ironmaking
byproduct gas; and
a refiner for refining the methane-containing ironmaking byproduct gas
1s exhausted from the first storage chamber.
7. The apparatus of claim 6, wherein the first pre-treating unit
further comprises:
a liquefied natural gas (LNG) injecting conduit for additionally supplying
20 methane to the methane-containing ironmaking byproduct gas exhausted from
the first storage chamber; and
a desulfurizer for removing sulfur from the liquefied natural gas.
8. The apparatus of claim 1, wherein the second pre-treating unit
comprises:
a second storage chamber for storing the carbon dioxide-containing
ironmaking byproduct gas; and
5 a refiner for refining the carbon dioxide-containing ironmaking byproduct
gas exhausted from the second storage chamber.
9. The apparatus of claim 8, wherein the second pre-treating unit
further comprises a carbon dioxide separator for separating carbon dioxide from
10 some or all of the refined carbon dioxide-containing ironmaking byproduct gas.
10. The apparatus of claim 9, wherein the carbon dioxide separator
receives heat from the off-gas exhausted from the reforming reaction unit.
11. The apparatus of claim 1, further comprises a pressure boosting
unit for boosting a pressure of the mixed gas, in which the methane-containing
ironmaking byproduct gas and the carbon dioxide-containing ironmaking
byproduct gas are mixed, to an operating pressure of the iron ore reducing unit.
12. The apparatus of claim 11, further comprising a temperature
raising unit for raising a temperature of the pressure-boosted mixed gas so as
to be appropriate for a reaction temperature in the reforming reaction unit.
13. The apparatus of claim 12, wherein the temperature raising unit
receives heat from the off-gas exhausted from the reforming reaction unit.
14. The apparatus of claim 1, further comprising a hydrogen
5 preparing unit for preparing hydrogen from some or all of a carbon monoxidecontaining
reducing gas prepared by reforming the mixed gas in the reforming
reaction unit.
15. The apparatus of claim 14, wherein the hydrogen preparing unit
lo further comprises:
a water-gas shift reactor for amplifying a hydrogen content of the carbon
monoxide-containing reducing gas; and
a hydrogen separator for separating hydrogen from the hydrogenamplified
carbon monoxide-containing reducing gas.
16. The apparatus of claim 15, wherein the hydrogen preparing unit
further comprises a heat recovery device for cooling the reformed carbon
monoxide-containing reducing gas.
17. The apparatus of claim 15, wherein the water-gas shift reactor
receives steam from the steam generating unit.
18. The apparatus of claim 15, wherein some of the hydrogen
BLY
separated by the hydrogen separator is supplied to the iron ore reducing unit
while being mixed with the carbon monoxide-mntaining reducing gas reformed
by the reforming reaction unit.
5 19. The apparatus of claim 15, wherein some of the hydrogen
separated by the hydrogen separator is exhausted to the outside in order to be
used for purposes other than reduction of iron ore.
20. The apparatus of claim 15, wherein the carbon dioxidelo
containing off-gas exhausted from the hydrogen separator is mixed with the
carbon dioxide-containing ironmaking byproduct gas.
21. The apparatus of any one of claims 1 to 20, wherein a mole ratio
of methane, carbon dioxide, and steam in the mixed gas supplied to the
15 reforming reaction unit satisfies Equations (1) and (2) below:
0 5 H2Q/C02 5 5 + * * ' (I)
20 22. An iron ore reducing system, the system being configured to
supply the synthetic gas containing carbon monoxide and hydrogen, which is
produced by the apparatus of any one of claims 1 to 21, to an iron ore reducing
unit to thereby reduce iron ore.
23. The system of claim 22, wherein the iron ore reducing unit is a
blast furnace or a fluidized reduction furnace in a FlNEX process.
5 24. A method for producing a synthetic gas containing carbon
monoxide and hydrogen, the method comprising:
pre-treating a methane-containing ironmaking byproduct gas;
pre-treating a carbon dioxide-containing ironmaking byproduct gas;
mixing the pre-treated methane-containing ironmaking byproduct gas
10 and the pre-treated carbon dioxide-containing ironmaking byproduct gas to
generate a mixed gas and then boosting a pressure of the mixed gas to a
predetermined pressure;
raising a temperature of the pressure-boosted mixed gas to a
predetermined temperature; and
supplying the temperature-raised mixed gas to a reforming reaction unit
to thereby reform the mixed gas into a carbon monoxide-containing reducing
gas.
25. The method of claim 24, wherein the pre-heating of the
ao methane-containing ironmaking byproduct gas comprises:
refining the methane-containing ironmaking byproduct gas; and
mixing the refined methane-containing ironmaking byproduct gas with
liquefied natural gas (LNG).
26. The method of claim 25, wherein the methane-containing
ironmaking byproduct gas is a coke oven gas (COG).
5 27. The method of claim 24, wherein the pre-heating of the carbon
dioxide-containing ironmaking byproduct gas comprises:
refining a carbon dioxide-containing ironmaking byproduct gas; and
separating carbon dioxide from some or all of the refined carbon
dioxide-containing ironmaking byproduct gas.
28. The method of claim 27, wherein the carbon dioxide-containing
ironmaking byproduct gas is at least one selected from an off-gas from a blast
furnace, an off-gas from a fluidized reduction fumace in a FlNEX process, an
off-gas from a power generator in an ironworks, an off-gas from a heating
15 furnace for producing steel products, and an off-gas from a coke oven heating
fumace.
29. The method of claim 28, wherein the carbon dioxide-containing
ironmaking byproduct gas further contains an off-gas exhausted from the
20 reforming reaction unit.
30. The method of claim 24, further comprising supplying steam to
the temperature-raised mixed gas.
31. The method of claim 24, further comprising preparing hydrogen
from some or all of the reformed carbon monoxide-containing reducing gas.
5 32. The method of claim 31, wherein the preparing of the hydrogen
comprises:
cooling the carbon monoxide-containing reducing gas;
water-gas shift converting the cooled carbon monoxide-containing
reducing gas; and
separating hydrogen from the water-gas shift converted reducing gas.
33. The method of any one of claim 24 to claim 32, wherein a mole
ratio of methane, carbon dioxide, and steam in the mixed gas supplied to the
reforming reaction unit satisfies Equations (1) and (2) below:
0 5 H201C02 5 5 - . - - (1)
34. A method for reducing iron ore by supplying the synthetic gas
20 containing carbon monoxide and hydrogen, which is produced by the method of
any one of claims 24 to 33, to an iron ore reducing unit to reduce iron ore.
35. The method of claim 34, wherein the iron ore reducing unit is a
w 2%
blast furnace or a fluidized reduction furnace in a FINEX process.