KR101384804B1 - Apparatus for manufacturing molten irons using the exhausted gas and method thereof - Google Patents

Abstract

Disclosed are a molten iron manufacturing apparatus and a manufacturing method capable of reducing carbon dioxide by using exhaust gas from a steelmaking process. The molten iron manufacturing apparatus according to the present invention is a combustor for generating heat by receiving a portion of the exhaust gas generated in the steelmaking furnace, the generator is connected to the combustor and generates electricity by steam using heat generated from the combustor, And receiving the remainder of the exhaust gas generated in the smelting furnace, connected to the generator, and receiving water vapor used for power generation to convert carbon monoxide from the effluent gas into hydrogen gas and injecting hydrogen gas converted into the smelting furnace again. Hydrogen gas maker. The present invention can increase the gas utilization rate by converting carbon monoxide in the exhaust gas generated in the iron making process into hydrogen and re-injecting it into the iron making furnace, thereby significantly reducing the amount of carbon dioxide generated in the steel mill.

Description

Apparatus for manufacturing molten irons using the exhausted gas and method

The present invention relates to a molten iron manufacturing apparatus and a manufacturing method, and more particularly to a molten iron manufacturing apparatus and a manufacturing method that can reduce the carbon dioxide by using the exhaust gas of the iron making process.

In general, a large amount of carbon is used as a reducing agent in an iron furnace that produces iron ore by reducing iron ore, which is directly connected to generation of carbon dioxide. Thus, carbon dioxide generated in the steel making process accounts for 80% of the total amount generated in the steel mill.

Until now, the use efficiency of reducing carbon has not been a big consideration because the focus has only been on the productivity of the steel mills.However, reducing the carbon consumption by improving the use efficiency of reducing carbons can reduce carbon dioxide. There is a need to develop a technology to reduce fuel and carbon dioxide emissions by reducing part of the exhaust gas to be reused in the smelter to reduce carbon monoxide that is not used as it is and to discharge all possible carbon in the form of carbon dioxide.

Exhaust gas from the steelmaking process was generally used for the heat source or power generation of the steelmaking process. Recently, technologies for storing carbon dioxide collected underground have been developed through the process of dioxide capture such as chemical adsorption and physical adsorption for the purpose of reducing carbon dioxide emissions.

The technology of capturing only carbon dioxide and storing it underground has its limitation in application due to lack of underground storage space or natural disasters. In addition, when the exhaust gas from which carbon dioxide has been removed is recycled to the smelting furnace, an excessive amount of nitrogen is re blown into the blast furnace together with carbon monoxide.

An object of the present invention is to provide a molten iron manufacturing apparatus and a manufacturing method for producing hydrogen gas using the exhaust gas generated in the integrated steelmaking process and to supply it back to the steel mill in order to solve the above problems.

An apparatus for manufacturing molten iron using exhaust gas of a steelmaking process according to a preferred embodiment of the present invention for achieving the above object includes an iron making line for preparing molten iron by charging coal with at least one of iron ore or reduced iron; A combustor configured to generate a heat by receiving a part of the exhaust gas generated in the first furnace; A generator which is connected to the combustor and generates electricity by steam using heat generated from the combustor; And receiving the remainder of the exhaust gas generated in the smelting furnace, connected to the generator, and receiving water vapor used for power generation to convert carbon monoxide from the effluent gas into hydrogen gas and injecting hydrogen gas converted into the smelting furnace again. Hydrogen gas maker.

The hydrogen gas generator is a water gas shift reactor (WGSR) for substituting carbon monoxide with hydrogen using the remainder of the supplied exhaust gas and water vapor supplied from the generator, the water gas shift reactor (WGSR) Compressor to increase the pressure of the hydrogen-containing discharge gas produced in the) and may be connected to the compressor pressure circulation adsorber (PSA) to increase the hydrogen content of the exhaust gas.

The smelting furnace may be any one of a melt gasification furnace of a Corex process, a melt gasification furnace of a Finex process, and a smelting furnace.

In the molten iron manufacturing method according to another preferred embodiment of the present invention is a method of manufacturing molten iron by charging at least one of iron ore or reduced iron and coal in the iron making furnace, the exhaust gas discharged from the iron making furnace to the combustor and hydrogen gas producer Separating; Reacting and combusting the exhaust gas supplied to the combustor with pure oxygen or air; Producing electricity from water vapor using heat generated in the combustor; Preparing hydrogen gas using a portion of the exhaust gas supplied to the hydrogen gas manufacturing apparatus and a part of steam used for power generation; And blowing the produced hydrogen gas back into the furnace.

The preparing of the hydrogen gas may be performed by a water gas shift reaction in which carbon monoxide of the supplied exhaust gas is replaced with hydrogen by using steam supplied from a generator.

After compressing the exhaust gas containing hydrogen produced by the water gas conversion reaction to 6 atm or more, the hydrogen content may be manufactured to 90% or more using a pressure circulation adsorber.

The temperature of the hydrogen gas in the step of blowing the hydrogen gas in the iron making process may be 800 ℃ or more.

The smelting furnace may be any one selected from a melt gasification furnace of a Corex process, a melt gasification furnace of a Finex process, and a smelting furnace.

According to the present invention, by converting carbon monoxide in the exhaust gas generated in the iron making process into hydrogen and re-injecting it into the iron making furnace, the gas utilization rate can be increased, and the amount of carbon dioxide generated in the steel mill can be greatly reduced.

1 is a block diagram showing a system diagram of a molten iron manufacturing apparatus according to an embodiment of the present invention.
2 is a process chart of the molten iron manufacturing method according to another embodiment of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified, and that other specific features, regions, integers, steps, operations, elements, components, and / And the like.

Hereinafter, with reference to the accompanying drawings will be described a hydrogen production and blowing apparatus using the exhaust gas in the steelmaking process according to a preferred embodiment of the present invention. For reference, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Figure 1 is a schematic diagram of a hydrogen gas blowing device using the exhaust gas production process according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus for manufacturing molten iron using the exhaust gas from the steelmaking process according to an embodiment of the present invention includes an iron mill 10 for preparing molten iron by charging coal with at least one of iron ore or reduced iron, and in the mill. Combustor 20 is connected to the combustor 20 to generate heat by receiving a portion of the exhaust gas generated by combustion, the generator 30 to generate electricity by steam using heat generated from the combustor 20 And receives the remainder of the exhaust gas generated in the furnace 10, is connected to the generator 30, receives the water vapor used for power generation to convert the carbon monoxide of the exhaust gas to hydrogen gas to switch back to the furnace Hydrogen gas makers 40, 50, and 60 which blow in the hydrogen gas which were used are included.

In the furnace 10, molten iron is produced by reducing and melting the raw material introduced through an iron ore sintering process and a coal coke process at a temperature of 1500 ° C. or higher. At this time, the emitted gas is usually 50% of nitrogen, 25% of carbon dioxide and reducing agent gas containing carbon monoxide is more than 20%.

The smelting furnace may be any one selected from a melting gasification furnace of the Corex process, a melting gasification furnace of the Finex process.

The Korex ^® process consists of a shaft furnace and a melt-gasifier, which produces reduced iron in the shaft furnace using iron ore and powdered coal with a constant particle size as a raw material, and produces the reduced iron in the melt gasifier. It is a process of manufacturing molten iron by charging it in the final reduction.

The Finex ^® process consists of a multi-stage fluidized bed reactor and a melt gasification furnace. The reduced iron is produced through a multi-stage fluidized-bed reactor using ferrous ore and pulverized coal as a raw material. It is a process of manufacturing molten iron by charging reduced iron into a melt gasifier and finally reducing it.

Combustor 20 is connected to the furnace 10, a part of the exhaust gas generated in the furnace 10 is introduced. Some combustion gases including carbon monoxide and hydrogen present in the injected exhaust gas are completely burned using pure oxygen or air to obtain heat required for the generator 30, and inert gases such as nitrogen and carbon dioxide can be obtained by complete combustion. Will be. At this time, the produced carbon dioxide may be stored separately.

The generator 30 is connected to the combustor 20 to generate electricity by using water vapor transmitted from the heat generated by the combustor 20. Some of the water vapor discharged from the generator 30 may be fed to the water gas shift reactor (WGSR) 40 of the hydrogen generator and used to produce hydrogen. The electricity produced by the generator 30 may also be used to drive the compressor 50 of the hydrogen generator. Therefore, since the heat generated by the combustion of the combustion gas components included in the exhaust gas is used for hydrogen production, there is an advantage that no separate power source is required.

On the other hand, the water vapor supplied from the generator to the water gas shift reactor (WGSR) 40 may be maintained at a temperature of 300 ~ 400 ℃ by a heat exchanger (not shown).

The hydrogen generator is connected to the furnace 10 with the combustor 20 to receive a part of the exhaust gas, and is a device for producing hydrogen gas by converting carbon monoxide contained in the exhaust gas into hydrogen. The hydrogen generator may include a water gas shift reactor (WGSR) 40, a compressor 50, and a pressure swing adsorber (PSA) 60.

The water gas shift reactor (WGSR) 40 reacts some of the exhaust gas supplied from the furnace 10 with the water vapor supplied from the generator 30 in the presence of a catalyst as shown in Equation (1). Will replace carbon monoxide with hydrogen.

CO + H2O → CO2 + H2 ---- (1)

The water gas shift reaction (water gas shift reaction) is carried out at a temperature of 200 ~ 350 ℃ and generates a reaction heat of 40.1kJ / mol as an exothermic reaction. When the reaction equilibrium value of the water gas shift reaction decreases at high temperature due to the exothermic reaction, and the conversion rate from carbon monoxide to hydrogen is lowered, the conversion rate to hydrogen may be further increased by low temperature water gas conversion.

Compressor 50 is connected to the water gas shift reactor (WGSR) 40, the exhaust gas containing hydrogen substituted in the water gas shift reactor (WGSR) 40 receives power from the generator 30 The pressure can be compressed to 6 atm or higher.

The compressor 50 is connected to a pressure circulating adsorber (PSA) 60. The pressure circulating adsorber (PSA) 60 includes a plurality of adsorbents in which a plurality of micropores are formed in an elongated tube, and the adsorbent serves as a filter.

As the adsorbent, a carbon molecular sieve may be used. The micropores may be formed to a size of several angstroms, and when the mixed gas passes through the adsorbent, a difference in the degree of adsorption for each gas component may occur depending on the size of the three micropores.

The exhaust gas whose pressure is increased through the compressor 50 may be separated into a hydrogen gas having a hydrogen content of 90% or more. More preferably, up to 95% or more can be produced.

Hydrogen gas separated through the pressure circulating adsorber (PSA) 60 may be introduced into the furnace 10. At this time, the hydrogen gas may be heated to a temperature of 800 ℃ or more. Hydrogen gas introduced into the iron making line 10 accelerates the iron ore reduction reaction in the iron making line 10, thereby contributing to the reduction of the reducing agent ratio.

In addition, the gas separated from the pressure circulating adsorber (PSA) 60 and released to the outside mainly consists of nitrogen and carbon dioxide. Among them, carbon dioxide can be separated and stored or recycled underground.

2 is a process chart of the hydrogen gas production and blowing method using the exhaust gas production process according to an embodiment of the present invention.

Hydrogen gas blowing method using the iron making process exhaust gas according to an embodiment of the present invention comprises the steps of separating the exhaust gas discharged from the furnace into a combustor and hydrogen gas producer (S10); Reacting and combusting the exhaust gas supplied to the combustor with pure oxygen or air (S20); Producing electricity from steam using heat generated in the combustor (S30); Preparing hydrogen using a portion of the exhaust gas supplied to the hydrogen gas producer and steam used for power generation (S40); And blowing back the produced hydrogen gas into the smelting furnace (S50).

Exhaust gas generated in the iron line 10 is a gas discharged after contributing to the iron ore reduction reaction is composed of nitrogen, carbon dioxide, carbon monoxide and other gases. Normally 50% of nitrogen, 25% of carbon dioxide, and reducing agent gas containing 20% of carbon monoxide is present in more than 20%. In the manufacturing method of molten iron using the exhaust gas of the steelmaking process according to an embodiment of the present invention, the exhaust gas is separated and part of it is used for power generation by complete combustion, and the remainder is converted into carbon monoxide contained in the exhaust gas into hydrogen furnace (10). It is possible to re-enter

After the purification process, the exhaust gas is separated into a combustor and a hydrogen gas maker (S10). Some are used for complete combustion in the combustor, and the remainder converts carbon monoxide contained in the exhaust gas to hydrogen gas in the hydrogen generator. Used.

The exhaust gas introduced into the combustor is completely combusted by reacting with pure oxygen or air. (S20) By the complete combustion, the heat required for power generation is obtained, and only inert gases such as carbon dioxide and nitrogen remain after the complete combustion. do. Carbon dioxide generated at this time can be separated and stored or recycled underground.

Heat generated in the combustion step is used to generate electricity by driving the turbine in the generator by raising the temperature of the steam supplied to the generator. (S30) The electricity produced in the generator drives the compressor 50 in the hydrogen gas manufacturing step. It is used to Energy may be saved because a separate power source is not required to drive the compressor 50.

The exhaust gas supplied to the hydrogen generator in the separation step reacts with a part of the water vapor discharged from the generator to produce hydrogen. (S40) The required water vapor in the hydrogen production step is maintained at 300 to 400 ° C. by heat exchange, and the water gas It may be supplied to the switcher (WGSR) 40. The aqueous conversion reaction replaces carbon monoxide in the exhaust gas with hydrogen.

After compressing the exhaust gas containing hydrogen produced by the water gas conversion reaction to 6 atm or more, the hydrogen content using a pressure circulation adsorber (PSA) can be produced to 90% or more.

Hydrogen gas separated by pressure circulation adsorption is again blown into the steelmaking process. (S50) At this time, the hydrogen is blown to 800 ℃ or more may be introduced. The preheating process can reduce the energy loss in the steelmaking process. Hydrogen injected back into the blast furnace accelerates the iron ore reduction reaction in the blast furnace and contributes to the reduction of the reducing agent ratio.

Carbon dioxide contained in the gas discharged from the pressure circulating adsorber (PSA) to the outside may be separated and stored or recycled underground.

10: furnace 20: burner
30: generator 40: water gas converter (WGSR)
50: compressor 60: pressure circulation adsorber (PSA)

Claims (8)

A furnace for preparing molten iron by charging coal with at least one of iron ore or reduced iron;
A combustor configured to generate a heat by receiving a part of the exhaust gas generated in the first furnace;
A generator which is connected to the combustor and generates electricity by steam using heat generated from the combustor; And
Receives the remainder of the exhaust gas generated in the smelting furnace, is connected to the generator, receives the water vapor used for power generation, converts the carbon monoxide contained in the exhaust gas into hydrogen gas and blows back the hydrogen gas converted to the smelting furnace again Hydrogen gas maker;
Including;
The hydrogen gas generator is a water gas shift reactor (WGSR) for substituting carbon monoxide with hydrogen using the remainder of the supplied exhaust gas and water vapor supplied from the generator, and receives electricity from the generator to convert the water gas shift reactor in the water gas shift reactor. And a pressure circulation adsorber (PSA) connected with the compressor to amplify the pressure of the exhaust gas containing hydrogen, and amplifying the hydrogen content of the exhaust gas.
The steelmaking furnace is any one selected from the melt gasification furnace of the Corex process, the melt gasification furnace and the blast furnace of the Finex process. delete delete In the method of manufacturing molten iron by charging at least one of iron ore or reduced iron and coal into the blast furnace,
Separating the exhaust gas discharged from the furnace into a combustor and a hydrogen gas producer;
Reacting and combusting the exhaust gas supplied to the combustor with pure oxygen or air;
Producing electricity from water vapor using heat generated in the combustor;
Manufacturing hydrogen gas by a water gas shift reaction using exhaust gas supplied to the hydrogen gas manufacturing apparatus and a part of water vapor used in the power generation, and electricity generated from a generator; And
And blowing the produced hydrogen gas back into the furnace.
After compressing the exhaust gas containing hydrogen produced by the water gas conversion reaction to 6 atm or more, using a pressure circulating adsorber to produce a hydrogen content of more than 90%,
The temperature of the hydrogen gas in the step of blowing the hydrogen gas in the iron making process, characterized in that more than 800 ℃. delete delete delete 5. The method of claim 4,
The steelmaking furnace is any one selected from the melt gasification furnace of the Corex process, the melt gasification furnace and the blast furnace of the Finex process.

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