JP3683498B2 - Method and apparatus for using iron carbide - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention relates to a method and apparatus that can be used for iron making after recovering hydrogen or the like from iron carbide as energy in an iron making method that uses iron carbide (iron anchor, Fe ₃ C), and efficient using iron carbide as a raw material. Further, the present invention relates to a method and an apparatus capable of performing power generation, iron making, and hydrogen production.
[0002]
[Prior art]
When iron ore is brought into contact with natural gas (methane gas) and hydrogen at a temperature of 550 to 700 ° C., the iron ore is reduced to metallic iron, and when the reaction continues, iron carbide (mainly Fe ₃ C) is produced. The ratio will increase.
Conventionally, pig iron was obtained by iron-making iron or iron carbide obtained by reducing iron ore together with scrap (scrap iron) in an electric furnace.
[0003]
Further, the present applicant has already obtained a patent as a technique for easily producing hydrogen using iron carbide and water (steam) as raw materials (Japanese Patent No. 2945585). In this patent, as described in Japanese Patent No. 2954585, hydrogen and iron are produced at a relatively low temperature and low pressure by a reaction of Fe ₃ C + H ₂ O → 3Fe + CO + H ₂ .
[0004]
[Problems to be solved by the invention]
When iron carbide obtained from iron ore is ironed, the carbon contained in the iron carbide in the electric furnace is carbon dioxide or carbon monoxide, and if possible, including the combustible gas generated at this time, the electric furnace It is desired to develop a system that can recover combustible gas from iron carbide and use it as energy before supplying it to the factory.
In addition, as a technique for more effectively using iron carbide, development of a method and apparatus capable of producing hydrogen, iron, and electric power together is desired.
[0005]
The present invention has been made in view of the above-described points. The object of the present invention is to generate hydrogen and carbon monoxide by reacting iron carbide with steam before making iron carbide in an electric furnace, and use this combustible gas as energy. And providing a method and apparatus capable of efficiently producing iron and energy by obtaining pig iron from iron carbide from which combustible gas is extracted.
In addition, the object of the present invention is to generate electricity in a battery using iron carbide as a fuel, to produce iron carbide after discharge in an electric furnace, and to thermochemically regenerate the iron carbide after discharge, An object of the present invention is to provide a method and apparatus capable of efficiently combining electric power, iron, and hydrogen.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the method of using iron carbide according to the present invention reacts iron carbide (iron anchor, Fe ₃ C) with water vapor or a gas containing water vapor, and hydrogen and carbon monoxide, which are combustible gases. Combustible gas, and at least part of the iron carbide is converted to iron, and after the combustible gas is taken out, iron and iron carbide are produced in an electric furnace to produce pig iron, and the recovered combustible gas It is comprised so that hydrogen and carbon monoxide which are may be utilized as energy (refer FIG. 1).
[0007]
Further, the method of the present invention reacts iron carbide with water vapor or a gas containing water vapor to generate a gas containing hydrogen and carbon monoxide, which are combustible gases, and converts at least a part of the iron carbide into iron. Then, iron and iron carbide after the combustible gas is taken out are produced in an electric furnace to produce pig iron, and the recovered combustible gas hydrogen and carbon monoxide are burned to generate power and / or recover heat. (Refer to FIG. 1).
In the method of the present invention described above, hydrogen can be produced from a gas containing recovered hydrogen and carbon monoxide (see FIG. 1).
Moreover, in these methods of this invention, the ratio of the iron supplied to an electric furnace, iron carbide, and scrap iron (scrap) can be set arbitrarily.
[0008]
In the method of the present invention, iron carbide is loaded on the negative electrode of the battery as a negative electrode active material, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. It is characterized in that at least a portion of the used negative electrode active material is hydroxylated and iron iron after discharge is produced in an electric furnace to obtain pig iron and hydrogen (see FIG. 2).
In the method of the present invention, iron carbide is loaded on the negative electrode of the battery as a negative electrode active material, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. Reducing iron carbide, which is dehydrated and oxidized by reducing at least a portion of the used negative electrode active material, which is hydroxylated, regenerates the iron carbide and regenerates it by producing hydrogen and oxidizing the used positive electrode active material The regenerated iron carbide and oxidizing agent are reused as battery active materials (see FIG. 2).
[0009]
In the method of the present invention, iron carbide is loaded on the negative electrode of the battery as a negative electrode active material, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. At least a part of the used negative electrode active material is hydroxylated, and a part of the iron carbide after discharge is made in an electric furnace to obtain pig iron and produce hydrogen, and at least a used negative electrode active material Reducing the remainder of the partially oxidized iron carbide to dehydrate and oxidize it to regenerate the iron carbide and produce hydrogen, regenerate by oxidizing the used positive electrode active material, It is characterized by reusing the oxidizing agent as the battery active material (see FIG. 2).
In these cases, examples of the oxidizing agent used for the positive electrode include MnO ₂ , NiOOH, O ₂ , and air.
Moreover, natural gas (methane gas) etc. are mentioned as an example as a reducing agent used for dehydration oxidation reaction of iron hydroxide carbide.
[0010]
In the method of the present invention described above, by allowing the iron carbide after discharge extracted from the battery to be supplied to the iron making process in the electric furnace and the regeneration process by dehydration oxidation at an arbitrary ratio, hydrogen, iron and One or two products of power can be produced independently with the required production quantity.
In these methods of the present invention, as the battery, the negative electrode active material powder is loaded into the electrolyte solution in one of the two containers connected via a member through which ions pass, and the other It is preferable to use a three-dimensional battery in which a positive electrode active material powder is loaded in an electrolyte solution in a container, and a conductor current collector is provided in two containers to be in contact with the active material powder (FIG. 4). reference). In addition, the present applicant has applied for many patents for the three-dimensional battery, and there are applications that have already obtained patents as Japanese Patent No. 3051401, and Japanese Patent Application Nos. 2000-332281 and 2000-332503.
[0011]
The apparatus for using iron carbide according to the present invention causes iron carbide to come into contact with water vapor or a gas containing water vapor to generate a gas containing hydrogen and carbon monoxide, which are combustible gases, and at least part of the iron carbide is made into iron. And an electric furnace that introduces iron and iron carbide after taking out combustible gas generated in the reactor as energy together with scrap iron (scrap) from outside the system, and produces pig iron by iron making , A power generation device including a combustion engine and a boiler for generating power and recovering heat by burning hydrogen and carbon monoxide, which are combustible gases recovered from the reactor, and a gas containing hydrogen and carbon monoxide recovered from the reactor And a hydrogen production apparatus (gas separation apparatus) that separates hydrogen from the catalyst (see FIG. 1).
In the apparatus of the present invention described above, it is preferable to use a fluidized bed reactor as the reaction apparatus (see FIG. 1). Of course, it is also possible to use a moving bed reactor or the like.
In the above-described apparatus of the present invention, it is preferable to use a gas turbine as a combustion engine in the power generation apparatus (see FIG. 1). Of course, it is possible to use a gas engine, a fuel cell, or the like.
[0012]
In the apparatus of the present invention, the powder of iron carbide as the negative electrode active material is loaded into the electrolyte solution in one of the two containers connected via a member through which ions pass, and the other container is filled with the powder. A three-dimensional battery in which an oxidant powder serving as a positive electrode active material is loaded in an electrolyte solution, and a current collector for a conductor that is in contact with the active material powder is provided in two containers, and a three-dimensional battery An electric furnace for producing pig iron and hydrogen by introducing iron carbide, which is at least partly hydroxylated after discharge, used for power generation, together with scrap iron (scrap) from outside the system, and producing iron and hydrogen A three-dimensional carbonization device that regenerates iron carbide by dehydrating and oxidizing iron carbide, which is at least partially hydroxylated, which is the negative electrode active material after discharge used for power generation in the original battery, and producing hydrogen. Positive electrode active material that has been used for battery power generation And the oxidizing device regenerated by the carbonizing device and the oxidizing agent regenerated by the oxidizing device are supplied to the three-dimensional battery as an active material. (See FIGS. 2 and 4).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications. FIG. 1 shows a schematic configuration of an apparatus for carrying out the iron carbide utilization method according to the first embodiment of the present invention. When iron ore (Fe ₃ O ₄ , Fe ₂ O _3, etc.) is brought into contact with natural gas (methane gas) and hydrogen at a temperature of 550 to 700 ° C., it is reduced to metallic iron, and when the reaction continues, iron carbide ( Mainly, Fe ₃ C) is produced, and its proportion increases. As shown in FIG. 1, iron ore is brought into contact with natural gas (hydrogen is not shown) in a fluidized bed reactor 10 to generate iron carbide (i-anchor baide). The carbonization proceeds appropriately to obtain iron carbide and iron. In this embodiment, the combustible gas is recovered as energy before the iron carbide is produced in an electric furnace. The reason why this embodiment is established is that, when measuring the powdering characteristics of iron carbide in the fluidized bed, it is confirmed that iron carbide reacts with saturated steam mixed by the scrubber and carbon monoxide and hydrogen are generated. Because. That is, as shown in FIG. 1, when iron carbide is reacted with water vapor or a gas containing water vapor in a fluidized bed reactor 12, carbon monoxide and hydrogen are obtained by the following reaction, and the iron carbide becomes iron.
Fe ₃ C + H ₂ O → 3Fe + CO + H ₂
[0014]
In order to obtain an economical reaction rate, the above reaction is preferably carried out at a temperature in the range of 400 to 800 ° C., desirably in the range of 500 to 680 ° C., more desirably in the range of 590 to 680 ° C. Is preferably 10 kg / cm ² · G or less, preferably in the range of atmospheric pressure to 6 kg / cm ² · G. Thus, in the above reaction, hydrogen is generated at a relatively low temperature of about 600 ° C., which is advantageous for subsequent processing and heat recovery.
In the fluidized bed reactor 12, a part of the iron carbide becomes iron, and iron and iron carbide obtained by taking out hydrogen and carbon monoxide are supplied to the electric furnace 14 for iron making. In addition to iron and iron carbide after generating hydrogen and the like, the electric furnace 14 is supplied with iron and iron carbide by direct reduction of conventional iron ore, and scrap iron scrapped as scrap. However, these supply amounts and supply ratios can be freely changed as required. In FIG. 1, as an example, in the process leading to scrap, iron making is performed by the converter / blast furnace method, but it is needless to say that the iron making method is not limited and the method of the present invention may be used.
[0015]
The combustible gas (hydrogen, carbon monoxide) generated in the fluidized bed reactor 12 is used, for example, for power generation by the gas turbine 16 and can recover and effectively use energy from iron carbide for making iron. It becomes. In FIG. 1, as an example, the obtained combustible gas (hydrogen, carbon monoxide) is introduced into the combustor 20 together with the compressed air from the compressor 18 and burned, and the turbine 22 is driven by the combustion gas to generate power. The machine 24 generates electricity. Further, the exhaust gas from the turbine 22 is introduced into the boiler 26 to generate steam. Although not shown, power can be generated by driving the steam turbine with this steam.
Further, a gas containing hydrogen and carbon monoxide generated in the fluidized bed reactor 12 can be introduced into a hydrogen production device (gas separation device) 28 to recover hydrogen, and hydrogen from iron carbide for producing iron Can be manufactured. As an example of the hydrogen production apparatus (gas separation apparatus), a membrane separation apparatus, a pressure swing system (PSA) separation apparatus, or the like is used.
[0016]
FIG. 2 shows a schematic configuration of an apparatus for carrying out the iron carbide utilization method according to the second embodiment of the present invention. The reaction in the fluidized bed reactor 10 is the same as in the first embodiment. In the fluidized bed reactor 10, carbonization proceeds appropriately to obtain iron carbide and iron. The iron carbide is supplied to the battery to generate power, and the production of electric power, iron, and hydrogen is performed efficiently. This is the present embodiment. In this embodiment, the grounds that iron carbide becomes the negative electrode active material of the battery are because it was confirmed that iron carbide discharges 299 Ah / kg coulomb at a potential of 0.88 volts with respect to silver / silver chloride. is there. The discharge curve at this time is shown in FIG. When an oxygen electrode is used as the positive electrode, the primary battery has a nominal voltage of 1.2 volts. It has also been confirmed that the discharge is a theoretical amount. Therefore, when iron carbide is supplied to a continuous chemical regeneration battery and power is generated, for example, power generation of 359 kWh per ton of iron carbide can be performed. As an example, the reaction formula when manganese dioxide is used as the positive electrode is shown below.
Negative electrode reaction Fe ₃ C + 2H ₂ O → Fe ₃ C (OH) ₂ + 2H ⁺ + 2e ⁻
Positive electrode reaction MnO ₂ + 2H ⁺ + 2e ⁻ → Mn (OH) ₂
Overall reaction Fe ₃ C + MnO ₂ + 2H ₂ O → Fe ₃ C (OH) ₂ + Mn (OH) ₂
[0017]
That is, as shown in FIG. 2, by supplying iron carbide (and iron) obtained by reducing iron ore in the fluidized bed reactor 10 to the three-dimensional battery 30, the iron carbide is used as the negative electrode active material, manganese dioxide. Thus, the three-dimensional battery 30 can be directly generated using iron carbide as a fuel. Here, the configuration of the three-dimensional battery will be described. As an example, as shown in FIG. 4, a negative electrode cell 36 and a positive electrode cell 38 are provided in a casing 32 via a separator 34, and the negative electrode cell 36 includes a negative electrode active material 40 and an electrolyte solution 42 (for example, potassium hydroxide). A positive electrode active material 44 and an electrolyte solution 42 are loaded in the positive electrode cell 38. The negative electrode active material 40 and the positive electrode active material 44 are powder or particles or a mixture of powder and particles. In addition, the separator 34 is a film | membrane which does not let electricity pass through ion, for example, unglazed, an ion exchange resin film | membrane, a metal fiber, etc. are used. Further, a negative electrode current collector 46 and a positive electrode current collector 48 made of a conductive material are provided in the negative electrode cell 36 and the positive electrode cell 38, respectively. As an example of the shape of the current collector, a plate shape, a rod shape, or a tubular shape is used, but other shapes can also be adopted. Although not shown, the negative electrode current collector 46 and the positive electrode current collector 48 are connected to the load means outside the casing 32. The active material is loaded as a fixed layer. In order to increase the contact efficiency between the active material and the current collector and between the active materials, fluidized fluid dispersion means using gas or liquid, mechanical stirring means, etc. The active material in each cell may be fluidized (stirred).
[0018]
In the present embodiment, when a three-dimensional battery as shown in FIG. 4 is used, iron carbide (and iron) is loaded into the negative electrode as the negative electrode active material 40, and an oxidizing agent such as manganese dioxide is used as the positive electrode active material 44 as the positive electrode. Is loaded. Since the negative electrode active material 40 is electrically connected between particles (powder) and also connected to the negative electrode current collector 46, the negative electrode active material 40 is electrically connected to the outside of the casing 32. Similarly, the positive electrode active material 44 is also electrically connected between the particles (powder) and is also connected to the positive electrode current collector 48, so that it is electrically connected to the outside of the casing 32. Such a three-dimensional battery generates power by the above-described reaction.
In this embodiment, a three-dimensional battery in which the active material is powder or particles is used. However, the structure of the battery is not limited, and a vent type or a cylindrical type can also be used.
[0019]
As described above, a part of the iron carbide is hydroxylated by the discharge in the three-dimensional battery 30. The hydroxylated iron carbide is thermochemically regenerated and an oxidizing agent (such as manganese dioxide) is chemically treated. By regenerating, this battery becomes a chemically regenerated battery that is charged thermochemically and discharged electrochemically, and continuous power generation is also possible. Details of this will be described later.
Further, iron and hydrogen can be produced by iron-hydrating hydrated iron carbide in the electric furnace 14. That is, as shown in FIG. 2, the iron carbide discharged in the three-dimensional battery 30 is extracted, and this hydroxylated iron carbide is supplied to the electric furnace 14 together with scrap iron (scrap) that is discarded and scrapped. Hesitate. The processes leading to scrap and the other raw materials supplied to the electric furnace 14 are the same as those in the first embodiment.
The iron hydroxide carbide conducts electricity and is melted in the electric furnace 14. At this time, iron (pig iron) is obtained by the following reaction, and carbon dioxide and hydrogen are generated. If this hydrogen and hydrogen converted from separately generated carbon monoxide are used as the product, for example, 12 kg of hydrogen per ton of iron carbide can be obtained. Since hydrogen is a high temperature, it can be used as it is for reduction of iron ore and nickel ore, but heat recovery is required to make hydrogen fuel. In FIG. 2, the step of separating hydrogen from the gas containing hydrogen and carbon dioxide generated in the electric furnace 14 is omitted.
Fe ₃ C (OH) ₂ → 3Fe + CO ₂ + H ₂
[0020]
Moreover, in order to increase the production ratio of hydrogen and electric power, dehydration oxidation reaction of iron hydroxide carbide is performed. That is, as shown in FIG. 2, the iron carbide discharged in the three-dimensional battery 30 is extracted, and this hydroxylated iron carbide is supplied to the carbonization furnace 50 and regenerated thermochemically. The reaction formula when reduced with natural gas is shown below. As shown in FIG. 2, the natural gas is pressurized by a gas compressor 52 or the like and supplied to the carbonization furnace 50. In this case, the pressure is 10 kg / cm ² · G or less, preferably 1 to 10 kg / cm ² · G range. The reaction temperature is in the range of 400 to 800 ° C, preferably in the range of 600 to 700 ° C. By returning iron hydroxide carbide to iron carbide thermochemically, the production ratio of hydrogen and electric power can be increased with respect to the production of iron in the electric furnace 14 described above. In FIG. 2, the step of separating hydrogen from a gas containing hydrogen and carbon dioxide generated in the carbonization furnace 50 is omitted. In addition, the used oxidizing agent (manganese dioxide in FIG. 2) is regenerated by being oxidized by the fluidized bed oxidation device 54, for example. The regenerated iron carbide and oxidant are reused in the battery 30, whereby the battery 30 is thermochemically charged and becomes a chemically regenerated battery that is electrochemically discharged. In this case, whether the iron carbide after discharge extracted from the three-dimensional battery 30 is supplied to the iron making process in the electric furnace 14 or the regeneration process by dehydration oxidation in the carbonization furnace 50 is arbitrarily determined. The ratio can be freely set, and two products of hydrogen, iron, and electric power can be independently manufactured at a required production amount.
Fe ₃ C (OH) ₂ + CH ₄ → Fe ₃ C + CO ₂ + 3H ₂
For example, if electricity is produced at 100 million kW, 8000 hours, that is, 800 billion kWh and iron is produced at 100 million tons, hydrogen is calculated to be produced at 76 million tons.
[0021]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects.
(1) In the iron making method using iron carbide, hydrogen and the like can be recovered from the iron carbide as energy and then used for iron making.
(2) Power generation, ironmaking, and hydrogen production can be efficiently performed using iron carbide as a raw material.
(3) Electric power can be generated directly by supplying iron carbide to the battery, and iron (pig iron) and hydrogen can be produced by iron making the discharged iron carbide in an electric furnace. It is possible to continuously generate power and to produce hydrogen. Moreover, it is possible to independently produce two of the three products of hydrogen, iron and electric power in the required amount.
[Brief description of the drawings]
FIG. 1 is a systematic schematic configuration explanatory view showing an apparatus for carrying out a method of using iron carbide according to a first embodiment of the present invention.
FIG. 2 is a systematic schematic configuration explanatory view showing an apparatus for carrying out a method of using iron carbide according to a second embodiment of the present invention.
FIG. 3 is a graph showing discharge characteristics of an iron carbide half-cell.
FIG. 4 is a schematic cross-sectional configuration diagram showing an example of a three-dimensional battery used in a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10, 12 Fluidized bed reaction furnace 14 Electric furnace 16 Gas turbine 18 Compressor 20 Combustor 22 Turbine 24 Generator 26 Boiler 28 Hydrogen production apparatus (gas separation apparatus)
30 three-dimensional battery 32 casing 34 separator 36 negative electrode cell 38 positive electrode cell 40 negative electrode active material 42 electrolyte 44 positive electrode active material 46 negative electrode current collector 48 positive electrode current collector 50 carbonization furnace 52 gas compressor 54 fluidized bed oxidation apparatus

Claims (6)

  It is a used negative electrode active material in which iron carbide is loaded as a negative electrode active material on the negative electrode of the battery, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. A method of using iron carbide, characterized in that at least part of the iron carbide after being discharged is ironed in an electric furnace to obtain pig iron and to produce hydrogen.   It is a used negative electrode active material in which iron carbide is loaded as a negative electrode active material on the negative electrode of the battery, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. Iron carbide that has been dehydrated and oxidized by reducing at least partly hydroxylated iron to regenerate iron carbide and produce hydrogen, and regenerated by oxidizing the used positive electrode active material. A method of using iron carbide, wherein the agent is reused as a battery active material.   It is a used negative electrode active material in which iron carbide is loaded as a negative electrode active material on the negative electrode of the battery, an oxidant serving as a positive electrode active material is loaded on the positive electrode of the battery, and power is generated in a battery using iron carbide as a fuel. Iron carbide, at least partly hydroxylated, is obtained by making a part of iron carbide after discharge, which has been hydroxylated, in an electric furnace to obtain pig iron and producing hydrogen. The remaining part of the steel is dehydrated and oxidized to regenerate iron carbide, produce hydrogen, regenerate by oxidizing the used positive electrode active material, and use the regenerated iron carbide and oxidizing agent as the battery active material A method of using iron carbide characterized by being reused. By making it possible to supply the iron carbide after discharge extracted from the battery at an arbitrary ratio to the iron making process in the electric furnace and the regeneration process by dehydration oxidation, one or two of hydrogen, iron and power The method for using iron carbide according to claim 3 , wherein the product can be manufactured independently with a required production amount. As a battery, the negative electrode active material powder is loaded into an electrolyte solution in one of two containers connected via a member through which ions pass, and the positive electrode active material is loaded into the electrolyte solution in the other container. The method of using iron carbide according to any one of claims 1 to 4 , wherein a three-dimensional battery is used in which powder is loaded and a current collector for a conductor in contact with the powder of the active material is provided in two containers . A powder of iron carbide, which is a negative electrode active material, is loaded in an electrolyte solution in one of two containers connected via a member through which ions pass, and a positive electrode active material in the electrolyte solution in the other container A three-dimensional battery provided with a current collector for a conductor that is loaded with an oxidant powder to be in contact with the active material powder in two containers;
An electric furnace for producing pig iron and hydrogen by introducing iron carbide, which is at least partially hydroxylated, which is a negative electrode active material after discharge used for power generation in a three-dimensional battery, together with scrap iron from outside the system,
A carbonization device for producing hydrogen by dehydrating and oxidizing iron carbide by reducing at least a portion of the hydroxide, which is a negative electrode active material after discharge used for power generation in a three-dimensional battery, to regenerate iron carbide;
Including an oxidizer that regenerates by oxidizing the positive electrode active material that has been used in power generation in a three-dimensional battery,
An iron carbide utilization apparatus characterized in that iron carbide regenerated by a carbonization apparatus and an oxidant regenerated by an oxidation apparatus are supplied as active materials to a three-dimensional battery.

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