FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
"APPARATUS FOR MANUFACTURING MOLTEN IRON"
POSCO, of 1, Goedong-dong, Nam-ku, Pohang-shi, Kyungsangbuk-do, 790-300, Republic of Korea;
The following specification particularly describes the invention and the manner in which it is to be performed.

TITLE OF THE INVENTION APPARATUS FOR MANUFACTURING MOLTEN IRON
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2009-0131399 filed in the Korean Intellectual Property Office on December 28, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an apparatus for manufacturing molten iron. More particularly, the present invention relates to an apparatus for manufacturing molten iron which can reduce an amount of generated carbon dioxide and produce a liquid fuel and electrical energy in molten iron manufacturing process.
(b) Description of the Related Art
Off-gases generated during a molten iron manufacturing process are harmful to the environment, and are undesirable in aspects of resource and energy efficiency as recyclable substances are wasted if discharged into the atmosphere as they are.
Further, carbon dioxide contained in off-gases causes climate changes, and needs to be retrieved and recycled.
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. SUMMARY OF THE INVENTION
The present invention has been made in an effort to provide an apparatus for manufacturing molten iron having advantages of reducing an amount of carbon dioxide generated in molten iron manufacturing process and recycling the generated carbon dioxide.
Further, the present invention has been made in an effort to provide an apparatus for manufacturing molten iron which can produce a liquid fuel and electrical energy in iron manufacturing process.
An exemplary embodiment of the present invention provides an apparatus for manufacturing molten iron, comprising: a melter-gasifier for producing molten iron and generating off-gases; a carbon dioxide reforming unit for reforming the off-gases and generating hydrogen and carbon monoxide; and an iron ore reducing unit for receiving the hydrogen and the carbon dioxide to reduce iron ore.
The apparatus for manufacturing molten iron may further comprise an off-gas refining facility installed between the melter-gasifier and the carbon dioxide reforming unit, wherein the off-gas refining facility may refine harmful substances in the off-gases. Further, the off-gas refining facility may comprise at least one of a cyclone, a filter, and a scrubber.
The apparatus for manufacturing molten iron may further comprise a gas distributing unit installed between the carbon dioxide reforming unit and the

iron ore reducing unit, wherein the gas distributing unit may supply some of the hydrogen and the carbon monoxide generated by the carbon dioxide reforming unit to the melter-gasifier and supply the remaining hydrogen and carbon monoxide to the iron ore reducing unit.
The apparatus for manufacturing molten iron may further comprise a first heat exchanger, wherein the first heat exchanger may supply heat generated by the melter-gasifier to the carbon dioxide reforming unit.
The apparatus for manufacturing molten iron may further comprise a steam separating unit connected to the iron ore reducing unit, wherein the steam separating unit may separate and remove water generated by the iron ore reducing unit.
The apparatus for manufacturing molten iron may further comprise an electric power generating unit connected to the steam separating unit, wherein the electric power generating unit may receive steam and mixed gas from the steam separating unit to produce electrical energy. Further, the electric power generating unit may be a turbine.
The apparatus for manufacturing molten iron may further comprise a steam reforming unit installed between the melter-gasifier and the carbon dioxide reforming unit, wherein the steam reforming unit may bring the steam in the off-gases into reaction with carbon monoxide to produce hydrogen.
The apparatus for manufacturing molten iron may further comprise a carbon dioxide separating unit installed between the melter-gasifier and the carbon dioxide reforming unit, wherein the carbon dioxide separating unit may separate carbon dioxide from the off-gases and send the carbon dioxide to the

carbon dioxide reforming unit, and send the remaining off-gases to the melter-gasifier. The carbon dioxide separating unit may be a PSA unit, or may separate carbon dioxide by using one of a cryogenic process, an ammonia/amine adsorbing process, an adsorbent using process, an MOF, and a membrane separation process.
The apparatus for manufacturing molten iron may further comprise a liquid fuel producing unit connected to the iron ore reducing unit, wherein the liquid fuel producing unit may receive mixed gas from the iron ore reducing unit and produce liquid fuel. Meanwhile, the liquid fuel produced by the liquid fuel producing unit may comprise at least one of methanol, di-methyl ether, and hydrocarbon. Further, the liquid fuel producing unit may be a slurry reactor.
The apparatus for manufacturing molten iron may further comprise a second heat exchanger, wherein the second heat exchanger may supply heat generated by the liquid fuel producing unit to the carbon dioxide reforming unit.
The apparatus for manufacturing molten iron may further comprise a compressor installed between the iron ore reducing unit and the liquid fuel producing unit.
The apparatus for manufacturing molten iron may further comprise an electric power generating unit connected to the liquid fuel producing unit, wherein the electric power generating unit may receive steam and mixed gas from the liquid fuel producing unit and produce electrical energy. The electric power generating unit may be a turbine.
The apparatus for manufacturing molten iron may further comprise a carbon dioxide separating unit installed between the liquid fuel producing unit

and the electric power generating unit, wherein the carbon dioxide separating unit may separate carbon dioxide from the mixed gas and send the carbon dioxide to the carbon dioxide reforming unit. The carbon dioxide separating unit may be a PSA unit, or may separate carbon dioxide by using one of a cryogenic process, an ammonia/amine adsorbing process, an adsorbent using process, an MOF, and a membrane separation process.
Another exemplary embodiment of the present invention provides an apparatus for manufacturing molten iron comprising: a first iron ore reducing unit for reducing iron ore and manufacturing reduced iron; a melter-gasifler for receiving the reduced iron to produce molten iron and generating off-gases; a carbon dioxide reforming unit for reforming the off-gases and generating hydrogen and carbon monoxide; and a second iron ore reducing unit for receiving the hydrogen and the carbon monoxide to reduce iron ore.
The apparatus for manufacturing molten iron may further comprise a off-gas refining facility installed between the melter-gasifier and the carbon dioxide reforming unit, wherein the off-gas refining facility may refine harmful substances in the off-gases.
The apparatus for manufacturing molten iron may further comprise a gas distributing unit installed between the carbon dioxide reforming unit and the iron ore reducing unit, wherein the gas distributing unit may supply some of the hydrogen and the carbon monoxide generated by the carbon dioxide reforming unit to the first iron ore reducing unit and supply the remaining hydrogen and carbon monoxide to the second iron ore reducing unit.
The first iron ore reducing unit or the second iron ore reducing unit may

be a fluidized-bed reduction furnace.
According to the exemplary embodiments of the present invention, it is possible to reduce an amount of carbon dioxide generated in an iron manufacturing process and recycle the generated carbon dioxide.
Further, according to the exemplary embodiments of the present invention, it is possible to produce a liquid fuel and electrical energy in an iron manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an apparatus for manufacturing molten iron according to the first exemplary embodiment of the present invention.
FIG. 2 is a schematic diagram showing an apparatus for manufacturing molten iron according to the second exemplary embodiment of the present invention.
FIG. 3 is a schematic diagram showing an apparatus for manufacturing molten iron according to the third exemplary embodiment of the present invention.
FIG. 4 is a schematic diagram showing an apparatus for manufacturing molten iron according to the fourth exemplary embodiment of the present invention.
FIG. 5 is a schematic diagram showing an apparatus for manufacturing molten iron according to the fifth exemplary embodiment of the present invention.
FIG. 6 is a schematic diagram showing an apparatus for manufacturing

molten iron according to the sixth exemplary embodiment of the present invention.
FIG. 7 is a schematic diagram showing an apparatus for manufacturing molten iron according to the seventh exemplary embodiment of the present invention.
FIG. 8 is a schematic diagram showing an apparatus for manufacturing molten iron according to the eighth exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
FIG. 1 is a schematic diagram showing an apparatus for manufacturing molten iron according to the first exemplary embodiment of the present invention.
Referring to FIG. 1, the apparatus for manufacturing molten iron according to an exemplary embodiment of the present invention comprises a melter-gasifier 110, a carbon dioxide reformer 120, an iron ore reducing unit 130, a off-gas refining facility 140, a steam separating unit 150, and an electric

power generating unit 160.
The melter-gasifier 110 is a facility for producing molten iron and slag and generating off-gases by using an iron-containing material and a carbon-containing material. The iron-containing material may be iron ore and the carbon-containing material may be coal.
Iron-containing material is reduced by carbon monoxide (CO) and hydrogen (hfe) in the melter-gasifier 110, and reduction reactions of iron-containing material are represented by Chemical Formulas 1 and 2 as follows.
1 J
- Fe70. + CO = -Fe + C07
3 J (1)
1 2
- Fe203 + H2 = - Fe + H20
3 3 (2)
The H2/CO mol ratio of the off-gases may be more than 0.5 at a temperature of 350 °C or higher.
The off- gases are supplied to the carbon dioxide refoming unit 120 via the off-gas refining facility 140. The off-gas refining facility 140 is installed between the melter-gasifer 110 and the carbon dioxide reforming unit 120, and is a facility for removing harmful substances contained in the off-gases, such as particulates, nitrogen oxides (NOx), sulfur oxides (SOx), and mercury. The off-gas refining facility 140 removes harmful substances by using a cyclone, a filter, or a scrubber.
The carbon dioxide reforming unit 120 reforms off-gases and generates hydrogen and carbon monoxide. That is, the carbon dioxide reforming unit 120 is a unit for bringing methane and carbon dioxide into reaction and generating

hydrogen and carbon monoxide, and the reforming reaction is represented by Chemical Formula 3 as follows.
CHA+C02^CO+H2 (3)
A fluidized-bed reactor may be used as the carbon dioxide reforming unit 120. By using a fluidized-bed reactor, catalyst deactivation due to deposition of carbon can be prevented and yields of produced hydrogen and carbon monoxide can be enhanced.
The hydrogen and carbon monoxide generated by the carbon dioxide reforming unit 120 are mixed with off-gases to generate mixed gas, and a ratio of hydrogen to carbon monoxide (H2/CO) in the mixed gas increases.
The mixed gas is supplied to a gas distributing unit 170. The gas distributing unit 170 supplies some of the mixed gas to the melter-gasifier 110 and the remaining mixed gas to the iron ore reducing unit 130.
As the mixed gas supplied to the melter-gasifier is supplied together with heat, an amount of produced molten iron can be further increased.
A first heat exchanger 180 may be installed between the melter-gasifier 110 and the carbon dioxide reforming unit 120. The first heat exchanger 180 supplies the heat generated by the melter-gasifier 110 to the carbon dioxide reforming unit 120.
The iron ore reducing unit 130 is a unit for receiving the mixed gas from the carbon dioxide reforming unit 120 to reduce iron ore and producing reduced iron. That is, the mixed gas serves as a reduction agent in the iron ore reducing unit 130.

The iron ore supplied to the iron ore reducing unit 130 may have average particle size smaller than that of the iron ore supplied to the melter-gasifier 110. For example, fine iron ore or ultra-fine iron ore having an average particle size of not more than 1 mm may be supplied to the iron ore reducing unit 130.
The iron ore reducing unit 130 may be a fluidized-bed reactor which may be operated at a temperature of not less than 700 °C and a pressure of not less than 3 bar. For example, the fluidized-bed reactor may be a bubbling, turbulent, or riser type. A counter-current type fluidized-bed reactor where ultra-fine iron ore descends and a reducing synthetic gas rises may be used.
An amount of iron in the reduced iron can be regulated or a reduction rate of the reduced iron can be increased by connecting several reactors in parallel or in series to extend a stay time of the iron ore in the reactors.
The steam separating unit 150 may be connected to the iron ore reducing unit 130. The steam separating unit 150 can separate and remove the steam generated in iron ore reducing process, and can also retrieve heat.
The electric power generating unit 160 is connected to the steam separating unit 150 to receive the steam and the mixed gas and produce electrical energy. The produced electrical energy may be supplied to each unit constituting the apparatus for manufacturing molten iron. The electric power generating unit 160 may be a turbine.
FIG. 2 is a schematic diagram showing an apparatus for manufacturing molten iron according to the second exemplary embodiment of the present invention.

Referring to FIG. 2, the basic elements of the apparatus for manufacturing molten iron according to the second exemplary embodiment of the present invention are the same as those of the first exemplary embodiment except that the apparatus for manufacturing molten iron according to the second exemplary embodiment further comprises a steam reforming unit 210.
The steam reforming unit 210 is installed between the melter-gasifier 110 and the carbon dioxide reforming unit 120. The steam reforming unit 210 brings steam in off-gases into reaction with carbon monoxide to generate hydrogen. The reforming reaction is represented by Chemical Formula 4 as follows.
H20+CO=H2 +C02
i -* ^ (4)
By adding steam into the steam reforming unit 210, an amount of hydrogen can be increased and carbon deposition can be reduced. The steam reforming unit 210 may not only be a fluidized-bed reactor but can also be a fixed-bed reactor. When a fluidized- bed reactor is used, a catalyst regenerating reactor may be installed to compensate, circulate, and regenerate a catalyst.
FIG. 3 is a schematic diagram showing an apparatus for manufacturing molten iron according to the third exemplary embodiment of the present invention.
Referring to FIG. 3, the basic elements of the apparatus for manufacturing molten iron according to the third exemplary embodiment of the present invention are the same as those of the second exemplary embodiment

except that the apparatus for manufacturing molten iron according to the third exemplary embodiment further comprises a liquid fuel producing unit 310.
The liquid fuel producing unit 310 is connected to the iron ore reducing unit 130 to receive mixed gas and produce a liquid fuel. The steam in the mixed gas generated by the iron ore reducing unit 130 is separated and removed by the steam separating unit 150, and the remaining mixed gas is supplied into the liquid fuel producing unit 310. The remaining mixed gas may be compressed by a compressor 320 before supplied into the liquid fuel producing unit 310.
The produced liquid fuel may be methanol, di-methyl ether, hydrocarbon, etc.
Methanol is finally produced through a hydrogenation reaction of carbon monoxide (CO), a hydrogenation reaction of carbon dioxide (C02), and a water gas shift reaction. The respective reactions are represented by Chemical Formulas 5 to 7 as follows.
CO+ 2H2 -> CH3OH (5)
C02 + 3H2 -> CH3OH + H20 (6)
CO+H20C02+H2
Di-methyl ether may be produced from methanol, and is represented by Chemical Formula 8 as follows.
2CH3OH -+CH2OCH2 + H2G (8) A slurry reactor which is one of the fluidized-bed reactors may be used

as the liquid fuel producing unit 120 to prevent deactivation of a catalyst due to carbon deposition.
The slurry reactor contains solid-state metallic catalyst and a liquid hydrocarbon wax and off-gases containing carbon dioxide, carbon monoxide, and hydrogen, and the off-gases react with the catalyst to produce a liquid fuel such as methanol.
The liquid hydrocarbon wax is a medium for transferring heat and materials, and a second heat exchanger 330 may be installed to retrieve the heat generated through an exothermic reaction. The second heat exchanger 330 is a unit for retrieving the heat generated by a liquid fuel producing unit 410 and transferring heat to the methane gas supplied to the carbon dioxide reforming unit 120. Thermal efficiency can be increased by an operation of the second heat exchanger 330.
Meanwhile, the structure of the liquid fuel producing unit 310 is not limited to a slurry reactor, and may include a fixed-bed reactor using off-gases and a catalytic layer.
The liquid fuel such as methanol produced by the liquid fuel producing unit 310 and water are separated from each other in a liquid fuel/water separator 340, and the generated mixed gas is supplied to the electric power generating unit 160.
FIG. 4 is a schematic diagram showing an apparatus for manufacturing molten iron according to the fourth exemplary embodiment of the present invention.
Referring to FIG. 4, the basic elements of the apparatus for

manufacturing molten iron according to the fourth exemplary embodiment of the present invention are the same as those of the third exemplary embodiment except that the apparatus for manufacturing molten iron according to the fourth exemplary embodiment further comprises a carbon dioxide separating unit 410.
The carbon dioxide separating unit 410 is installed between the liquid fuel producing unit 310 and the electric power generating unit 160. The carbon dioxide separating unit 410 separates carbon dioxide from the mixed gas generated by the liquid fuel producing unit 310, and sends the carbon dioxide to a carbon dioxide distributor 420. The carbon dioxide distributer 420 sends some of the carbon dioxide to the carbon dioxide reforming unit 120 and sends the remaining carbon dioxide to a carbon dioxide concentrating and storing unit (not shown).
A pressure swing adsorption (PSA) unit may be used as the carbon dioxide separating unit 410. Further, units using a cryogenic process, an ammonia/amine adsorbing process, an adsorbent using process, a metal organic framework (MOF), and a membrane separation process may be used as the carbon dioxide separating unit 410.
FIG. 5 is a schematic diagram showing an apparatus for manufacturing molten iron according to the fifth exemplary embodiment of the present invention.
Referring to FIG. 5, the basic elements of the apparatus for manufacturing molten iron according to the fifth exemplary embodiment of the present invention are the same as those of the first exemplary embodiment except that the apparatus for manufacturing molten iron according to the fifth

exemplary embodiment further comprises a carbon dioxide separating unit 510.
The carbon dioxide separating unit 510 is installed between the off-gas refining facility 140 and the carbon dioxide reforming unit 120. The carbon dioxide separating unit 510 retrieves only carbon dioxide from the off-gases and sends the carbon dioxide to the carbon dioxide reforming unit 120, and sends the remaining off-gases to the melter-gasifier 110.
The carbon dioxide separating unit 510 may be a PSA unit. The carbon dioxide separating unit 510 may be a unit for separating carbon dioxide by using one of a cryogenic process, an ammonia/amine adsorbing process, an adsorbent using process, a metal organic framework (MOF), and a membrane separation process.
FIG. 6 is a schematic diagram showing an apparatus for manufacturing molten iron according to the sixth exemplary embodiment of the present invention.
Referring to FIG. 6, the basic elements of the apparatus for manufacturing molten iron according to the sixth exemplary embodiment of the present invention are the same as those of the fifth exemplary embodiment except that the apparatus for manufacturing molten iron according to the sixth exemplary embodiment further includes a liquid fuel producing unit 610.
A description of the liquid fuel producing unit 610 is a duplicate of that of the third exemplary embodiment and thus will be omitted.
FIG. 7 is a schematic diagram showing an apparatus for manufacturing molten iron according to the seventh exemplary embodiment of the present invention.

Referring to FIG. 7, the basic elements of the apparatus for manufacturing molten iron according to the seventh exemplary embodiment of the present invention are the same as those of the sixth exemplary embodiment except that the apparatus for manufacturing molten iron according to the seventh exemplary embodiment further comprises a carbon dioxide separating unit 710.
A description of the carbon dioxide separating unit 710 is a duplicate of that of the fourth and fifth exemplary embodiments and thus will be omitted.
FIG. 8 is a schematic diagram showing an apparatus for manufacturing molten iron according to the eighth exemplary embodiment of the present invention.
A description of the elements similar to or the same as those of the first exemplary embodiment among the elements of the apparatus for manufacturing molten iron according to the eighth exemplary embodiment of the present invention will be omitted.
A first iron ore reducing unit 810 is a unit for reducing iron ore and manufacturing reduced iron. A melter-gasifier 820 receives reduced iron to produce molten iron.
The gas distributing unit 170 supplies some of the hydrogen and carbon monoxide generated by the carbon dioxide reforming unit 120 to the first iron ore reducing unit 810 and supplies the remaining hydrogen and carbon dioxide to a second iron ore reducing unit 830. The first iron ore reducing unit 810 or the second iron ore reducing unit 830 may be a fluidized-bed reduction furnace.
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 arrangements included within the spirit and scope of the appended claims.

\J$