WO2018216886A1 - Method for preparing hydrogen gas - Google Patents

Abstract

A method for preparing hydrogen gas, according to embodiments of the present invention, comprises the steps of: generating carbon dioxide (CO₂) by using steelmaking slag; generating hydrogen gas by reacting a gas containing methane (CH₄) with carbon dioxide (CO₂); and recovering the generated hydrogen gas. Therefore, according to embodiments of the present invention, hydrogen gas can be produced by recycling steelmaking slag. In addition, since steelmaking slag is used as a material for producing hydrogen gas, the amount of steelmaking slag to be reclaimed can be reduced, thereby enabling environmental pollution to be reduced.

Description

Hydrogen gas production method

The present invention relates to a method for producing hydrogen gas, and more particularly, to a method for producing hydrogen gas by efficiently utilizing by-products generated in a steel mill and using the by-products.

Slag generated in the steelmaking process is mainly generated by the flux added to remove impurities in the molten iron.

During the steelmaking process, the operation removes impurities such as sulfur (S), phosphorus (P), and carbon (C), that is, slag (converter slag) generated in the converter in which refining operation is performed, and sulfur (S) in molten iron before the converter operation. The pretreatment slag generated during the deflow treatment to remove) may contain metal oxides such as limestone (CaO), magnesium oxide (MgO), silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and iron oxide (Fe _x O _y ). Included. In particular, in the converter, an operation for refining the molten iron provided in the blast furnace is carried out.

In general, the quicklime injected into the molten iron does not form a compound by reacting with the molten iron in its entirety and remains in a surplus state, thereby leaving free lime in the slag, and part of the quicklime in the compound may be precipitated as free lime.

When the slag reacts with water, the pH becomes very strong about 11 to 12, and when it enters seawater or the like, it forms white turbid water and causes environmental pollution.

Therefore, attempts have been made to recycle steelmaking slag, but there is a limit to the use of the recycled steel. Currently, only recycling aggregates are used, and the recycling rate is very low.

In general, nickel (Ni) is one of very important metals as an alloying element of steel. With the development of the machinery industry, the demand for nonferrous alloys, stainless steels, plating, corrosion resistance, heat resistant materials, and magnetic materials is increasing day by day.

In the case of smelting nickel, ferronickel (Fe-Ni) slag, which is about 30 times of the production amount, is generated as a by-product through complex connection production lines such as raw materials, steelmaking, and steelmaking. In general, steel slag, blast furnace slag and steelmaking slag is composed of calcium oxide (CaO) and silicon dioxide (SiO ₂ ) components, whereas ferronickel (Fe-Ni) slag is silicon dioxide (SiO ₂ ) and magnesium oxide Magnesium silicate slag containing (MgO) as a main component. Therefore, it can be supplied to a steel mill as a magnesium oxide (MgO) source which is a slag forming agent for steelmaking. Ferronickel (Fe-Ni) slag is recycled in advanced countries such as Japan and Canada as raw materials for cement manufacturing, civil engineering materials, concrete aggregates, runway aggregates, serpentine substitutes, etc. It is a landfill.

In addition, the ferronickel (Fe-Ni) slag discharged at 1 million tons per year will generate more than 2 million tons of waste slag per year due to the increase of additional facilities, and it is very difficult to find new uses such as recycling of ferronickel (Fe-Ni) slag. It's urgent.

(Prior literature)

Korea Patent Registration KR1559879B1

Korea Patent Publication KR10-2015-0076954

The present invention provides a hydrogen gas production method and a hydrogen gas production apparatus capable of recycling steel slag.

The present invention provides a hydrogen gas production method and a hydrogen gas production apparatus capable of producing hydrogen by efficiently utilizing by-products generated in the steelmaking process.

The present invention provides a hydrogen gas production method and a hydrogen gas production apparatus that can recycle carbon dioxide gas generated in steel mills.

The present invention provides a hydrogen gas production method and a hydrogen gas production apparatus capable of generating hydrogen gas used as fuel gas from a magnesium compound produced from slag.

Hydrogen gas production method according to the invention using the steelmaking slag, the process of producing carbon dioxide (CO ₂ ); Reacting gas containing methane (CH ₄ ) with the carbon dioxide (CO ₂ ) to generate hydrogen gas; And recovering the generated hydrogen gas.

In the reaction of the gas containing methane (CH ₄ ) and the carbon dioxide (CO ₂ ), it is preferable to react at a temperature of 900 ℃ to 1100 ℃.

The methane (CH ₄₎ gas and the carbon dioxide (CO ₂₎ the method sikineunde reaction, the methane of (CH ₄₎ gas and the carbon dioxide (CO ₂₎ mixed gas mixture is containing the carbon dioxide containing (CO ₂ ) is 40% to 60 mol% (mol%), and it is preferable to mix so that the remainder is a gas containing methane (CH ₄ ).

The gas containing methane (CH ₄ ) includes a gas generated in steel mills.

The gas containing methane (CH ₄ ) includes coke oven gas (COG) generated during coke dry distillation in a coke oven.

Gas including the methane (CH ₄₎ preferably includes a gas than methane (CH ₄₎ is 90%.

In the process of reacting the gas containing methane (CH ₄ ) with the carbon dioxide (CO ₂ ), carbon monoxide is produced.

Hydrogen gas production method comprising the step of separating the hydrogen gas and carbon monoxide gas.

The steel slag may be any one of steel slag including 5 wt% or more of CaO and steel slag including 5 wt% or more of a magnesium compound.

The process of producing carbon dioxide (CO ₂ ) using the steelmaking slag, the process of producing a solid containing CaCO ₃ using the steelmaking slag containing 5 wt% or more of CaO; And separating carbon dioxide (CO ₂ ) from the solids.

The process of preparing the solid may include preparing an aqueous solution by mixing the steel slag with water; And blowing a gas containing carbon dioxide into the aqueous solution to prepare a solid containing CaCO ₃ .

In the process of separating carbon dioxide from the solid, the solid is heat-treated at a temperature of 900 ℃ to 1200 ℃, to dissociate carbon dioxide from the solid.

The process of producing carbon dioxide (CO ₂ ) using the steel slag, the process of extracting magnesium eluate by treating the steel slag containing the magnesium compound of 5 wt% or more with a solvent containing an acid; Hydrolyzing the magnesium eluate to produce a solid comprising a magnesium compound; And separating carbon dioxide (CO ₂ ) from the solids.

In the extracting of the magnesium eluate, the solid silicon dioxide (SiO ₂ ) is separated from the steel slag to extract the magnesium eluate.

The process of preparing the solid may include preparing a magnesium hydroxide (Mg (OH) ₂ ) solution by hydrolyzing the magnesium eluate; And a step of preparing a solid magnesium carbonate (Mg (CO ₃ )) by injecting and carbonizing a gas containing carbon dioxide (CO ₂ ) in the magnesium hydroxide (Mg (OH) ₂ ) solution.

The process of separating carbon dioxide (CO ₂ ) from the solid, heat treatment of the solid to a temperature of 900 ℃ to 1200 ℃, dissociate carbon dioxide from the solid.

Hydrogen gas production apparatus according to an embodiment of the present invention, the carbon dioxide production apparatus for producing carbon dioxide (CO ₂ ) using the steelmaking slag; A reaction apparatus for producing a gas containing hydrogen (H ₂ ) by reacting a gas including carbon dioxide (CO ₂ ) generated in the carbon dioxide manufacturing apparatus with methane (CH ₄ ); And a separation device that separates hydrogen (H ₂ ), gas other than hydrogen (H ₂ ) from the gas generated in the reaction device.

The reaction apparatus reacts the carbon dioxide (CO ₂ ) and methane (CH ₄ ) at a temperature of 900 ℃ to 1100 ℃.

In the reaction apparatus, carbon monoxide (CO) is generated together with the hydrogen (H ₂ ), and the separation apparatus separates the hydrogen and carbon monoxide.

The carbon dioxide production apparatus, the aqueous solution manufacturing unit for producing an aqueous solution by mixing the slag and the solvent; A solid production unit for preparing carbon solids by injecting carbon dioxide (CO ₂ ) gas into a product generated from the aqueous solution production unit; It includes; and a firing unit for separating the carbon dioxide (CO ₂ ) by firing the solid produced in the solid production apparatus.

According to the embodiment of the present invention, the steel slag can be recycled to produce hydrogen gas. In addition, since steel slag is used as a raw material for producing hydrogen gas, the amount of steel slag to be buried can be reduced, thereby reducing environmental pollution.

In addition, as the carbon dioxide generated in the steel mill is recycled in producing hydrogen gas, the amount of carbon dioxide emitted to the atmosphere can be reduced. In addition, quicklime (CaO) is formed in the process of producing hydrogen gas, which can be recycled to steelmaking processes, such as molten iron refining, thereby reducing the cost of raw materials for refining.

It is also possible to produce hydrogen (H ₂ ) gas that can be utilized as an energy source as fuel gas, thereby reducing the use and consumption of non-renewable energy sources such as petroleum, natural gas and coal.

In addition, through the recycling of quicklime (CaO), silicon dioxide (SiO ₂ ) and magnesium oxide (MgO), etc., which are separated from the by-product treatment method according to an embodiment of the present invention, it can bring about an additional profit and cost reduction effect. In addition, there is an effect that can minimize the environmental pollution due to the reduction of carbon dioxide (CO ₂ ).

1 is a flow chart showing a hydrogen gas production method according to an embodiment of the present invention

2 is a flowchart illustrating a process of producing carbon dioxide (CO ₂ ) gas using steelmaking slag according to the first embodiment of the present invention.

3 is a block diagram showing a hydrogen gas production apparatus according to an embodiment of the present invention

4 is a block diagram of a carbon dioxide (CO ₂ ) manufacturing apparatus according to a first embodiment of the present invention

5 is a graph showing the amount of production of hydrogen (H ₂ ) and CO gas (mol%) according to temperature in the method for producing hydrogen gas according to an embodiment of the present invention.

6 is a graph showing the amount of production of hydrogen (H ₂ ) and CO gas (mol%) over time in the hydrogen gas production method according to an embodiment of the present invention

7 is a flowchart illustrating a process of producing carbon dioxide (CO ₂ ) gas using steelmaking slag according to the second embodiment of the present invention.

8 is a block diagram of a carbon dioxide (CO ₂ ) manufacturing apparatus according to a second embodiment of the present invention

9 is a view showing a material produced by the hydrogen gas production method according to a second embodiment of the present invention

10 is a view showing a change in the concentration of magnesium ions eluted when the slag according to the second embodiment of the present invention is treated with a solution containing an acid

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like numbers refer to like elements in the figures.

1 is a flow chart showing a hydrogen gas production method according to an embodiment of the present invention. 2 is a flowchart illustrating a process of producing carbon dioxide (CO ₂ ) gas using steelmaking slag according to the first embodiment of the present invention. 3 is a block diagram showing a hydrogen gas production apparatus according to an embodiment of the present invention. 4 is a block diagram of a carbon dioxide (CO ₂ ) manufacturing apparatus according to a first embodiment of the present invention. 5 is a graph showing a production amount (mol%) of hydrogen (H ₂ ) and CO gas according to temperature in the hydrogen gas production method according to an embodiment of the present invention. 6 is a graph showing the amount (mol%) of hydrogen (H ₂ ) and CO gas with time in the hydrogen gas production method according to an embodiment of the present invention. 7 is a flowchart illustrating a process of producing carbon dioxide (CO ₂ ) gas using steelmaking slag according to the second embodiment of the present invention. 8 is a block diagram of a carbon dioxide (CO ₂ ) manufacturing apparatus according to a second embodiment of the present invention. 9 is a view showing a material produced by the hydrogen gas production method according to a second embodiment of the present invention. FIG. 10 is a view showing a change in concentration of magnesium ions eluted when treating slag with an acid-containing solution according to a second embodiment of the present invention.

The present invention relates to a hydrogen gas production method for producing hydrogen gas using by-products generated in steel mills.

Hydrogen gas manufacturing method according to embodiments of the present invention, as shown in Figure 1, the process of producing carbon dioxide (CO ₂ ) gas using the steel slag (S100), the generated carbon dioxide gas and methane (CH ₄ ) to the gas reaction, including (S200), hydrogen (H ₂₎ the process of separating the hydrogen (H ₂₎ gas from a process gas containing hydrogen (H ₂₎ gas to produce a gas containing gas (S300) It includes.

The hydrogen gas production apparatus for producing hydrogen gas by the method as shown in FIG. 1 described above, as illustrated in FIG. 3, a carbon dioxide production apparatus 10 for producing and producing carbon dioxide (CO ₂ ) from steel slag, Reaction device 20 for generating hydrogen (H ₂ ) gas by reacting the generated carbon dioxide (CO ₂ ) gas with a gas containing methane (CH ₄ ), and hydrogen (H) in the gas generated in the reaction device 20. ₂ ) a separation device 30 for separating the gas.

Embodiments of the present invention may be divided into the first embodiment and the second embodiment according to the type of slag utilized for generating hydrogen gas. That is, the embodiment of the present invention and to generate CO ₂ gas using the CaO of the slag, which was used for the magnesium of the first embodiment, the slag compound utilizing the hydrogen gas production generate CO ₂ gas, hydrogen them A second embodiment utilized for gas production is included.

First, the hydrogen gas production method and the hydrogen gas production apparatus according to the first embodiment will be described.

In the process of generating carbon dioxide (CO ₂ ) gas according to the first embodiment (S100), as shown in FIG. 2, a process of preparing an aqueous solution containing steel slag by mixing steel slag and a solvent (S110). , Blowing a gas containing carbon dioxide (CO ₂ ) into the aqueous solution to prepare a solid (S120), and firing the solid to separate carbon dioxide from the solid (S130).

As shown in FIG. 4, the carbon dioxide manufacturing apparatus 10 according to the first embodiment may include an aqueous solution manufacturing unit 11 for preparing an aqueous solution by mixing steel slag and a solvent, and preparing a solid using the aqueous solution. followed by firing the part 12, and a solid plastic part 13 to separate CO _2.

The aqueous solution manufacturing unit 11 may include a container in which the steel slag and the solvent are accommodated, and a stirrer for mixing the steel slag and the solvent in the container by stirring. The stirrer may be applied with any means capable of stirring the steel slag and the solvent in the vessel, for example, may be an impeller.

The solid manufacturing unit 12 may include a container in which an aqueous solution in which steelmaking slag and a solvent are mixed is accommodated, and a gas blowing member that blows gas including carbon dioxide (CO ₂ ) into the container. Here, the gas blowing member may be any means capable of communicating with the inside of the container and supplying a gas containing carbon dioxide (CO ₂ ) to the inside of the container, and may be, for example, a pipe or a nozzle.

The firing unit 13 may include a container capable of accommodating the solid material, a heating member providing heat for firing the solid material in the container or the container. The firing unit 13 may be applied to any means capable of firing solids so that carbon dioxide (CO ₂ ) can be separated, and may be, for example, a kiln or an kiln, such as an electric furnace.

First, each process (S100) of generating carbon dioxide (CO ₂ ) gas using steel slag will be described.

First, an aqueous solution is prepared by mixing steel slag and water as a solvent (S110).

The steel slag utilized in the first embodiment includes free lime, and slag having a stagnant CaO of at least 5 wt% is used. More specifically, steel slag is used to remove impurities such as phosphorus (P) and carbon (C) from molten iron or molten steel, that is, slag (converter slag) generated from converters in which refining operations are performed, and sulfur in molten iron prior to the converter operation. It may be at least one of the pretreatment slag generated during the deflow treatment to remove (S). Such steel slag may include not only glass lime, but also metal oxides such as limestone (CaO), magnesium oxide (MgO), silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and iron oxide (Fe _x O _y ).

When the above-described steelmaking slag and water as a solvent are provided, they are charged into a container of the aqueous solution manufacturing unit 11 and mixed by operating a stirrer. When steel slag containing free lime (free CaO) and water are mixed, Ca ions are eluted with water to prepare an alkaline aqueous solution having a pH of 11 or more (Formula 1). The pH of the aqueous solution can be controlled by adjusting the mixing amount of the steel slag.

[Formula 1]

^{_{CaO + H 2 O = Ca 2+}} + 2OH -

As described above, when making the aqueous alkali solution, it is preferable to adjust the variables such as the mixing ratio of the steel slag and water, the stirring speed and the reaction temperature to make the aqueous solution within a short time from the slag. That is, when preparing an aqueous alkali solution, it is preferable to proceed very quickly within 5 minutes, and it is preferable to try several times to elute 50% or more of free lime. In addition, in consideration of the elution time and efficiency, it is preferable that the steel slag, for example, the converter slag is separated into a sieve to obtain a size of 200 µm or less. At this time, when the size of the converter slag exceeds 200㎛, the surface area of the slag increases and the reaction rate with water is reduced.

In producing an alkaline aqueous solution by mixing steel slag and water, the metal ions of the steel slag are extracted with a solvent, that is, water, thereby making an alkaline aqueous solution. That is, when the steel slag is stirred and mixed with water by a stirrer, calcium ions (Ca ²⁺ ) are extracted. Therefore, the alkaline aqueous solution prepared by the steel slag may include calcium ions (Ca ²⁺ ).

On the other hand, the ionic component contained in the alkaline aqueous solution is not limited to the above components, and may include various ionic components included in the converter slag and the pretreated slag.

It is preferable that pH of aqueous alkali solution is manufactured to 11 or more. When the pH is made of more than 11, an improvement in the response rate of the ions in the aqueous solution with CO ₂ in the subsequent step of blowing a gas containing CO _2. That is, when the pH of the aqueous solution has a value of 11 or more, the binding of CO ₂ and alkaline ions is easy, and it is easy to precipitate a solid.

In other words, since alkaline ions (Ca ²⁺ ) are eluted in the aqueous solution, the higher the pH, the more solids can be obtained.

Therefore, in the present invention, in order to prepare an alkaline aqueous solution having a high pH of 11 or more, the aqueous solution was prepared by adjusting the conditions of slag: water = 1: 10.

However, the pH of the aqueous solution is not limited thereto, and the process of adjusting the pH of the aqueous solution if the reaction of ions in the alkaline aqueous solution with CO _{2 in} the by-product gas or the precipitation of solids can be facilitated regardless of the pH value. May not be required.

Next, the prepared aqueous solution is charged into a container of the solid preparation part 12, and a gas containing carbon dioxide (CO ₂ ) is blown into the aqueous solution in the container using a gas blowing member to prepare a solid including CaCO ₃ . (S120). In blowing a gas containing carbon dioxide (CO ₂ ) into the aqueous solution, it may be blown at 0.1 L per minute. However, the blowing amount of the gas is not limited to the above value and can be blown at an easy rate for the carbonation reaction. Moreover, generally, it may be blown in by the blowing amount of the gas blown into aqueous solution.

The gas containing carbon dioxide may be a by-product gas generated in a steel mill. More specifically, the gas including carbon dioxide may be at least one of Linz Donawitz Gas (LDG), Coke Oven Gas (COG), Blast Furnish Gas (BFG), and Finex Off Gas (FOG).

As such, by recycling the by-product gas generated in the steel mill in the production of solids, it is not necessary to provide a separate carbon dioxide gas, there is an effect that the cost for this is reduced.

When gas containing carbon dioxide is blown into an aqueous solution, carbon dioxide is dissolved as carbonate ions in the aqueous solution. Accordingly, Ca alkaline ions and carbonate ions contained in the aqueous alkali solution are carbonated to form a solid product including CaCO ₃ carbonate as shown in the following Formula 2. In other words, the carbonation reaction between the aqueous alkali solution and carbon dioxide produces a carbonate solid in which carbon dioxide is fixed or trapped. In addition, since the aqueous solution may contain ions such as Mg, carbonates such as MgCO ₃ may be further included.

[Formula 2]

Ca (OH) ₂ + CO ₂ → CaCO ₃ ↓ + H ₂ O

Solids trapped or immobilized with carbon dioxide are generally dried outside the aqueous solution in the form of sludge, which is a precipitate from sewage treatment or water purification. In this case, in order to separate the solids from the aqueous solution, the solids may be separated from the aqueous solution using a device generally used in a filtration process. Thus, the present invention is not limited to the apparatus and method for separating the solids, and satisfies the formation of a carbonate compound in which carbon dioxide is collected.

Solids containing CaCO ₃ carbonate consist of small particles of cubic form of 5 μm or less.

In order to separate carbon dioxide from such solids, the solids are calcined at a temperature of 900 ° C. to 1200 ° C. (S130). To this end, the solids are charged into a container, such as a firing furnace, in the firing unit, and the firing unit or solid is heat-treated at a temperature of 900 ° C to 1200 ° C. Accordingly, the solid material is fired, so that the carbon dioxide is dissociated from the solid material. A dissociation reaction is a phenomenon in which a molecule is divided into atoms, ions, or molecules smaller than ions. Thus, it can be seen that carbon dioxide is dissociated from the solid as shown in Chemical Formula 3 below.

[Formula 3]

CaCO ₃ + heat → CaO + CO ₂

On the other hand, when the temperature atmosphere for dissociating carbon dioxide is carried out at less than 900 ℃, there is a problem that the dissociation reaction of carbon dioxide does not occur because a sufficient process atmosphere is not provided until the carbon dioxide dissociates.

On the contrary, when the temperature atmosphere is performed at a temperature higher than 1200 ° C., efficiency is reduced in terms of energy consumption in a process for inducing dissociation reaction of carbon dioxide. That is, even when heated to a temperature exceeding 1200 ℃, the efficiency of dissociation reaction can not obtain a proportional value, so the amount of dissociated carbon dioxide can not be increased compared to the energy consumption, and the energy consumed in the dissociation process is increased only energy consumption. This increases. Therefore, the dissociation step is performed in the range of 900 ° C to 1200 ° C. However, the process temperature of the dissociation reaction is not limited to the above range, the change of ± 50 ℃ may occur depending on the size of the solids.

The firing unit 13 from which carbon dioxide is separated from the solid as described above may be processed using, for example, a kiln or a kiln. The absorbed carbon dioxide is sucked and recovered by absorbing gas from the calcining unit 13, for example, a kiln or kiln, in which the dissociation reaction occurs. In this case, any one of various devices capable of inhaling or absorbing gas may be used to recover gaseous carbon dioxide vaporized from a solid. In this case, the apparatus for recovering carbon dioxide is not limited, but various apparatuses capable of inhaling gas and collecting them in a predetermined space may be used.

In addition, when carbon dioxide is dissociated from the solid, CaO is generated as shown in Chemical Formula 3, which can be recycled to a steelmaking process such as molten iron refining, and the cost of raw materials for refining is reduced.

In the first embodiment, hydrogen gas is generated using carbon dioxide recovered by dissociation or separation from solids in the same manner as described above.

Referring to FIG. 1, a carbon dioxide gas separated and recovered from a solid including CaCO ₃ is reacted with a gas including methane (CH ₄ ) (S200) to generate a gas including hydrogen (H ₂ ). That is, when the gas containing carbon dioxide and methane (CH ₄ ) separated and recovered from the solid containing CaCO ₃ is supplied to the reaction apparatus 20 and reacted with each other, hydrogen (H ₂ ) and carbon monoxide as shown in Formula 4 below are reacted. A gas containing (CO) is produced.

[Formula 4]

CO ₂ + CH _4- > 2CO + 2H ₂

In the embodiment it is reacted at a temperature of 900 ℃ to 1100 ℃. At this time, the reaction apparatus 20 may use a kiln or chelin.

CO ₂ dissociation easily occurs at a temperature of 950 ° C. or higher, and even at temperatures of 900 ° C. or higher and less than 950 ° C., the CO ₂ is not as easy as that at 950 ° C. or higher, depending on the composition of steelmaking slag and the operating environment.

When the gas containing carbon dioxide and methane (CH ₄ ) is mixed and treated at less than 900 ° C., the reaction efficiency is low, and thus, the amount of production of hydrogen (H ₂ ) gas (mol%) is low.

On the contrary, when the temperature atmosphere exceeds 1100 ° C., the efficiency is reduced in terms of energy consumption in the process for the reaction between carbon dioxide and methane (CH ₄ ).

That is, referring to FIG. 5, as the temperature increases, the generation rate of CO ₂ increases, and at a temperature of 900 ° C. or more, the generation rate of CO ₂ is 60% or more. By the way, even when temperature was raised to a temperature exceeding 1100 ℃, the generation rate of CO ₂ does not increase, the increment is very small. In other words, when the firing temperature exceeds 1100 ° C., the CO ₂ production rate is the same or almost no difference when the firing temperature is 1100 ° C.

Therefore, the reaction process between carbon dioxide and a gas containing methane (CH ₄ ) is carried out at 900 ℃ to 1100 ℃. 5, the gas containing carbon dioxide and methane (CH ₄ ) is preferably reacted at 950 ° C. to 1100 ° C., and more preferably at 1000 ° C. to 1100 ° C.

As described above, through the reaction between carbon dioxide and a gas containing methane (CH ₄ ), not only hydrogen (H ₂ ) but also carbon monoxide (CO) are generated together, and the gas containing carbon dioxide and methane (CH ₄ ) is reacted. by a temperature at which a 900 ℃ to 1100 ℃, can produce hydrogen (H ₂₎ production of gas (mol%) to 60% to 75% (see Fig. 5).

In addition, in the reaction of mixing the carbon dioxide separated from the solid recovered and the gas containing methane (CH ₄ ), the carbon dioxide in the mixed gas is 40 mol% to 60 mol%, preferably 45 mol% to 55 mol%, more Preferably it is 50 mol%.

For example, when the carbon dioxide in the mixed gas is less than 40 mol% or more than 60 mol%, there is less carbon dioxide and methane (CH ₄ ) that can participate in the reaction, so that the amount of hydrogen (H ₂ ) gas generated (mol%) is low.

Therefore, in the embodiment of the present invention, the carbon dioxide in the mixed gas is 40 mol% to 60 mol%, the rest is a gas containing methane (CH ₄ ), more preferably 50 mol% carbon dioxide gas, methane (CH ₄ The gas containing) is 50 mol%.

In addition, in the reaction apparatus, in which a reaction gas is mixed with carbon dioxide and methane (CH ₄ ), the reaction time is 10 minutes or more, preferably 20 minutes or more (see FIG. 6). For example, when the reaction time is less than 10 minutes, the amount (mol%) of hydrogen (H ₂ ) gas is low.

In this way, the gas containing carbon monoxide (CO) and hydrogen (H ₂ ) is recovered from the reaction device 20, and the carbon monoxide (CO) and hydrogen (H ₂ ) are separated and recovered.

In separating carbon monoxide (CO) and hydrogen (H ₂ ), a separation device 30 may be used within or in connection with the reaction device 20. The separation device 30 may be a pressure swing adsorption (PSA) device that strongly adsorbs gas components other than hydrogen (that is, CO), a device including a hydrogen separation membrane using molecular size, and the like. Of course, the present invention is not limited thereto, and the separation device 30 may apply various devices capable of separating carbon monoxide and hydrogen. When hydrogen is separated by the separation device 30, hydrogen is separated in one of the reactor and the separation device 30 so that carbon monoxide is received in the other, and each of them is recovered.

The recovered hydrogen gas can be recycled as an energy source in steel mills, and carbon monoxide can be recycled as a heat source.

As described above, according to the first exemplary embodiment of the present invention, hydrogen gas may be produced by recycling the steel slag. In addition, since steelmaking slag is used as a raw material for producing hydrogen gas, the amount of steelmaking slag buried can be reduced, thereby reducing environmental pollution.

In addition, as the carbon dioxide generated in the steel mill is recycled in producing hydrogen gas, the amount of carbon dioxide emitted to the atmosphere can be reduced. In addition, quicklime (CaO) is formed in the process of producing hydrogen gas, which can be recycled to steelmaking processes, such as molten iron refining, thereby reducing the cost of raw materials for refining.

Next, a hydrogen gas production method according to the second embodiment will be described. In this case, the content duplicated with the above description may be omitted or may be briefly described.

The hydrogen gas producing method and the hydrogen gas producing apparatus according to the second embodiment are partially similar or identical to the first embodiment described above.

As shown in FIG. 1, the hydrogen gas manufacturing method according to the second exemplary embodiment includes a step (S100) of generating carbon dioxide (CO ₂ ) gas using steelmaking slag, and the generated carbon dioxide gas and methane (CH ₄ ). to the gas reaction to (S200), hydrogen (H ₂₎ the process for producing a gas containing gas, hydrogen (H ₂₎ comprising the step (S300) of separating the hydrogen (H ₂₎ gas from the gas containing gas do.

In addition, the process of generating carbon dioxide (CO ₂ ) gas using the steel slag (S100), as shown in Figure 7, the step of preparing a slag (S140), by treating the steel slag with an acid-containing solvent magnesium Extracting the eluate (S150), hydrolyzing the magnesium eluate to produce a solid containing a magnesium compound (S160), firing a solid containing a magnesium compound to separate carbon dioxide (CO ₂ ) (S170) It includes.

As illustrated in FIG. 8, the carbon dioxide manufacturing apparatus 10 according to the second embodiment includes an aqueous solution manufacturing unit 11 for preparing an aqueous solution by mixing steel and slag with a solvent, and a solid residue from a product manufactured in the aqueous solution manufacturing unit. The solid-liquid separator 14 for separating the solids, the solids manufacturing unit 12 for producing a solid using the magnesium eluate separated in the solid-liquid separator 14, and the firing unit 13 for firing the solid to separate the CO ₂ Include.

Herein, the aqueous solution manufacturing unit 11, the solid manufacturing unit 12, and the firing unit 13 according to the second embodiment may be the same as the first embodiment described above.

In the second embodiment, more specifically, magnesium slag containing at least 5 wt% or more of magnesium oxide (MgO) is used. Preferably, slag containing 50 to 60% by weight of silicon dioxide (SiO ₂ ) and 30 to 40% by weight of magnesium oxide (MgO) relative to the total weight of the slag can be used, and the steel slag is ferronickel ( Fe-Ni) may include ferronickel slag generated in the process of refining.

In general, slag as a by-product of the steelmaking process includes blast furnace slag and steelmaking slag. Such blast furnace slag and steelmaking slag are composed of calcium oxide (CaO) and silicon dioxide (SiO ₂ ) components, while ferronickel slag, another by-product of the steelmaking process, is slag produced by refining ferronickel and silicon dioxide. Magnesium silicate slag composed of (SiO ₂ ) and magnesium oxide (MgO) as main components.

ingredient MgO SiO ₂ Fe ₂ O ₃ CaO Al ₂ O ₃ Na ₂ O K ₂ O Ferronickel slag 31.1 55.5 11.7 0.3 2.2 0.1 0.1

As shown in Table 1, the ferronickel slag contains about 55% by weight of silicon dioxide (SiO ₂ ) and about 31% by weight of magnesium oxide (MgO).

In the hydrogen gas production method according to the first embodiment, a silicon compound is prepared by separating silicon dioxide (SiO ₂ ) from steelmaking slag, and a fuel such as hydrogen (H ₂ ) gas from carbon dioxide (CO ₂ ) dissociated from the magnesium compound. To prepare a gas, hereinafter, a case in which ferronickel slag is used for convenience of explanation, but 50 to 60% by weight of silicon dioxide (SiO ₂ ) and 30 to 40% by weight relative to the total weight The same applies to the case where the slag containing magnesium oxide (MgO) is used.

First, the process of preparing slag (S140) is prepared by grinding and classifying ferronickel slag which is a by-product of the steelmaking process. Here, the ferronickel slag is preferably crushed to have a particle size of 75㎛ or less. This is to maximize the reaction efficiency with the acid in the process of treating with an acid-containing solution (acid leaching) to be described later by widening the specific surface area.

A classification process may be performed after the grinding process, and the classification process is a process of classifying the crushed ferronickel slag by a certain particle size. This is to select the ferronickel slag crushed to a particle size of 75㎛ or less.

The process of separating the magnesium eluate (S150) is a process of eluting and extracting magnesium from the crushed and classified ferronickel slag. This may include a process of eluting magnesium and a process of separating the magnesium eluate.

In leaching magnesium, an acid leaching method may be used, and the leaching of magnesium elutes magnesium by treating the slag with a solvent containing an acid. That is, when a solvent containing an acid is charged into the container of the aqueous solution manufacturing unit 11 and slag is added thereto, magnesium is dissolved in the slag and is present in the solution as magnesium ions.

As the acid used in the acid-containing solution, sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl), nitric acid (HNO ₃ ) and the like may be used. Here, hydrochloric acid (HCl) and nitric acid (HNO ₃ ) is an efficient acid, but very expensive compared to sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl) has a problem that can corrode the facility because it is strong corrosive. Therefore, it is preferable to use sulfuric acid (H ₂ SO ₄ ) which is inexpensive and advantageous in terms of economics.

The sulfuric acid (H ₂ SO ₄ ) solution used in the process of pulverizing magnesium by treating the ground and classified slag with an acid-containing solvent is maintained at a high concentration of 1.0M to 5.0M. This is in order to shorten the reaction time, the concentration of sulfuric acid (H ₂ SO ₄₎ solution of 1.0M or less Mg leach rate is very low, the processing solution used in a concentration of more sulfuric acid (H ₂ SO ₄₎ solution of 5.0M This is because there is a problem.

In addition, the ratio of ferronickel slag and sulfuric acid (H ₂ SO ₄ ) solution is maintained at 100 to 300g / L to proceed with the reaction. This is because the productivity decreases when the ratio of ferronickel slag and sulfuric acid (H ₂ SO ₄ ) solution is less than 100g / L, and the process is inefficient if more than 300g / L. Therefore, when the process is made within the above range can be processed efficiently.

The process of eluting magnesium is a reaction at 50 degrees Celsius to 100 degrees Celsius, the stirring rate is preferably maintained at 200 to 500 rpm. This is because the leaching rate of magnesium ions increases as the leaching temperature increases, and is intended to increase the reaction efficiency through stirring.

After the magnesium is eluted, the magnesium eluted solution is separated. In the process of separating the magnesium eluate (S150), the solid-liquid separator 14 may be a solid-liquid separator widely used in the art. According to the solid-liquid separation process, silicon dioxide (SiO ₂ ) remaining as a magnesium eluate and a solid residue is separated from the ferronickel slag. Here, the magnesium eluate refers to a solution from which magnesium is eluted, and more specifically, a solution from which magnesium ions are eluted.

Formula 5 is a reaction formula for extracting a magnesium compound from a serpentine (Mg ₃ Si ₂ O ₅ (OH) ₄ ), a magnesium silicate mineral having a similar component to ferronickel slag.

[Formula 5]

Mg ₃ Si ₂ O ₅ (OH) ₄ + 3H ₂ SO ₄ → 3Mg ²⁺ + 3SO ₄ ^2- + 2SiO ² + 5H ₂ O

As can be seen from the formula (5), by the acid leaching method using sulfuric acid (H ₂ SO ₄ ) is separated from the magnesium silicate mineral, the magnesium eluate eluted with silicon dioxide (SiO ₂ ) and magnesium (Mg) ions.

That is, as shown in FIG. 9, which shows a material produced by the hydrogen gas production method according to the second embodiment, ferronickel slag containing silicon dioxide (SiO ₂ ) and magnesium oxide (MgO) as main components is When treated with an acid, a reaction similar to that of the serpentine (Mg ₃ Si ₂ O ₅ (OH) ₄ ) is generated. Magnesium ions are eluted at 85% after 20 minutes at 100 g / L of pulp density when treated with a solution containing acid and eluted to about 95% after 60 minutes.

That is, ferronickel slag having a component similar to serpentine can be used to replace serpentine, and even when ferronickel slag is used, a magnesium eluate in which silicon dioxide (SiO ₂ ) and magnesium (Mg) ions are eluted by acid leaching. This is separated.

As such, the extracting or separating the magnesium eluate (S150) may extract the magnesium eluate by separating the solid silicon dioxide (SiO ₂ ) from the ferronickel slag. Here, the separated high purity silicon dioxide (SiO ₂ ) may be formed into a powder after washing with neutral water 2 to 4 times, and then filtered and dried.

The solid containing a magnesium compound can be manufactured using the magnesium eluate obtained by the above method.

That is, the process of preparing a solid containing a magnesium compound (S160) to produce a magnesium compound by hydrolyzing the magnesium eluate. Here, the process of producing a solid containing a magnesium compound (S160) is a process of producing a magnesium hydroxide (Mg (OH) ₂ ) solution by hydrolyzing the magnesium eluate (S161) and magnesium hydroxide (Mg (OH) ₂ ) Carbonation of the solution may include the step of preparing a solid magnesium carbonate (Mg (CO ₃ )) (S162).

The process of preparing a magnesium hydroxide (Mg (OH) ₂ ) solution (S161) is a process of hydrolyzing by applying an alkali component to the magnesium eluate. To this end, the magnesium eluate and the alkaline component are charged into a container of the solid preparation part and mixed. This produces a magnesium compound, the alkaline component may be an alkaline hydroxide. At least one of sodium hydroxide (NaOH) and potassium hydroxide (KOH) may be used for the alkaline hydroxide. In the hydrolysis process according to the embodiment, sodium hydroxide (NaOH) is used, and the pH range of the eluate is adjusted. The pH range is preferably 8 to 12. More preferably, the pH range may be adjusted to 10-12. This is because the higher the pH value, the better the reactivity of magnesium and the more efficiently magnesium hydroxide (Mg (OH) ₂ ) can be obtained.

Meanwhile, the method may further include removing impurities before the hydrolysis process. The process of removing impurities is a process of purifying using a hydrogen peroxide (H ₂ O ₂ ) solution. Purification is a process of removing impurities present in the magnesium eluate. At this time, it is preferable to use a hydrogen peroxide (H ₂ O ₂ ) solution having a hydrogen peroxide (H ₂ O ₂ ) equivalent ratio of 0.8 to 1.2.

In the process of preparing magnesium carbonate (Mg (CO ₃ )) (S162), the magnesium hydroxide (Mg (OH) ₂ ) solution is carbonated to prepare solid magnesium carbonate (Mg (CO ₃ )). This is a process of preparing magnesium carbonate (MgCO ₃ ) by adding a gas containing carbon dioxide (CO ₂ ) to a magnesium hydroxide (Mg (OH) ₂ ) solution after an intermediate hydrolysis process. This reaction can be represented by the following formula (6).

[Formula 6]

Mg (OH) ₂ + CO ₂ → MgCO ₃ + H ₂ O

That is, when a gas containing carbon dioxide (CO ₂ ) is added to the magnesium hydroxide (Mg (OH) ₂ ) solution, magnesium ions present in the solution react with the CO-containing component supplied from the gas. Magnesium is reacted with CO-containing components more easily than with OH, resulting in magnesium carbonate (MgCO ₃ ). Here, the gas containing carbon dioxide (CO ₂ ) may include at least one of by-product gas generated in a steel mill process, for example, blast furnace gas (BFG) and linze donawitz gas (LDG). . By recycling the gas, converter gas may be used. The converter gas is a gas generated in the process of melting iron, and is composed of carbon dioxide (CO ₂ ) and carbon monoxide (CO), which is suitable as a carbon dioxide (CO ₂ ) source. The addition flow rate of the gas is preferably added at ¹ Nm ³ / min · ton or more in consideration of the reaction time and the reaction efficiency. Through this, it is possible to reduce the harmful carbon dioxide emitted to the atmosphere by using a gas containing carbon dioxide (CO ₂ ) generated in the steel mill. In addition, it can be used without separating the carbon dioxide (CO ₂ ) of the exhaust gas generated in the steel mill.

The process of separating carbon dioxide (CO ₂ ) (S170) calcinates a solid compound including a magnesium compound, that is, magnesium carbonate (MgCO ₃ ) to dissociate carbon dioxide (CO ₂ ).

To this end, a solid containing magnesium carbonate (MgCO ₃ ) is charged into the container of the baking unit 13, and the baking unit 13 or the solid is heat-treated at a temperature of 900 ℃ to 1200 ℃. By this firing, magnesium carbonate (MgCO ₃ ) is separated into magnesium oxide (MgO) and carbon dioxide (CO ₂ ). Here, the magnesium carbonate (MgCO ₃ ) is preferably heat-treated at a temperature of 1000 ℃ or more, 1200 ℃ or less, the firing unit may be a kiln or kiln, such as an electric furnace.

Through the above process, it can be obtained by dissociating carbon dioxide (CO ₂ ) from ferronickel slag. Further, in this process, silicon dioxide (SiO ₂ ) and magnesium compounds (Mg (OH) _2, MgCO _3, MgO) may be separated and obtained. Here, the various magnesium compounds obtained can be used again in the steelmaking process.

On the other hand, when the temperature of the firing unit 13 is less than 900 ° C, a sufficient process atmosphere until carbon dioxide is dissociated is not provided, and thus a dissociation reaction of carbon dioxide does not occur.

In addition, when the temperature of the firing unit 13 is performed at a temperature higher than 1200 ° C., efficiency is reduced in terms of energy consumption in a process for inducing dissociation reaction of carbon dioxide.

Referring to FIG. 1, a carbon dioxide gas separated and recovered from a solid containing magnesium carbonate (MgCO ₃ ) is reacted with a gas containing methane (CH ₄ ) (S200) to produce a gas containing hydrogen (H ₂ ). Create That is, a gas containing hydrogen (H ₂ ) as shown in Formula 4 below by reacting a gas containing methane (CH ₄ ) with high purity carbon dioxide (CO ₂ ) dissociated in the above-described firing process, in other words, a fuel gas Can be prepared.

At this time, the temperature for reacting carbon dioxide and methane (CH ₄ ) is 900 ℃ to 1100 ℃, preferably 950 ℃ to 1100 ℃, more preferably from 1000 ℃ to 1100 ℃. Through this, it is possible to produce the amount of hydrogen (H ₂ ) gas (mol%) from 60% to 75%.

In this case, the gas containing methane (CH ₄ ) may be a high purity methane (CH ₄ ) gas, and coke oven gas (COG) containing 20 to 30% of methane (CH ₄ ) may be used. Can also be used. Here, carbon monoxide (CO) gas and hydrogen (H ₂ ) gas produced as a fuel gas is separated, carbon monoxide (CO) gas is used as a heat source, hydrogen (H ₂ ) gas can be utilized as an energy source.

The separation device 30 recovers a gas containing carbon monoxide (CO) and hydrogen (H ₂ ) from the reaction device 20, and separates and recovers carbon monoxide (CO) and hydrogen (H ₂ ), respectively. When hydrogen is separated by the separating device 30, hydrogen is separated into one of the reaction device 20 and the separating device 30 so that carbon monoxide is contained in the other, and each of them is recovered.

The recovered hydrogen gas can be recycled as an energy source in steel mills, and carbon monoxide can be recycled as a heat source.

Thus, according to the hydrogen gas production method according to the second embodiment, high-purity silicon dioxide (SiO ₂ ) is separated from the slag, and a practical fuel gas can be produced from carbon dioxide (CO ₂ ) dissociated from the manufactured magnesium compound. From this, it is possible to improve the utilization of the slag that was entirely buried.

It is also possible to produce hydrogen (H ₂ ) gas that can be utilized as an energy source as fuel gas, thereby reducing the use and consumption of non-renewable energy sources such as petroleum, natural gas and coal.

In addition, through the recycling of silicon dioxide (SiO ₂ ) and magnesium oxide (MgO) and the like separated from the hydrogen gas manufacturing method according to the embodiment it can bring the effect of additional revenue generation and cost reduction, carbon dioxide (CO ₂ ) There is an effect that can minimize the environmental pollution due to the reduction of.

In the above, while the preferred embodiment of the present invention has been described and illustrated using specific terms, such terms are only for clearly describing the present invention, and the embodiments of the present invention and the described terms are used in the technical spirit of the following claims. It is obvious that various changes and modifications can be made without departing from the scope of the present invention. Such modified embodiments should not be understood individually from the spirit and scope of the present invention, but should fall within the claims of the present invention.

According to the hydrogen gas production method according to embodiments of the present invention, the hydrogen slag can be recycled to produce hydrogen gas. In addition, since steel slag is used as a raw material for producing hydrogen gas, the amount of steel slag to be buried can be reduced, thereby reducing environmental pollution.

Claims (20)

Producing carbon dioxide (CO ₂ ) using steel slag; Reacting gas containing methane (CH ₄ ) with the carbon dioxide (CO ₂ ) to generate hydrogen gas; And Recovering the generated hydrogen gas; Hydrogen gas production method comprising a. The method according to claim 1, In reacting the gas containing methane (CH ₄ ) with the carbon dioxide (CO ₂ ), Process for producing hydrogen gas to react at a temperature of 900 ℃ to 1100 ℃. The method according to claim 1, In reacting the gas containing methane (CH ₄ ) with the carbon dioxide (CO ₂ ), Among the mixed gas in which the gas containing methane (CH ₄ ) and the carbon dioxide (CO ₂ ) are mixed, the carbon dioxide (CO ₂ ) is 40% to 60 mol% (mol%), and the balance is methane (CH ₄ ). Hydrogen gas production method for mixing to be a gas containing. The method according to claim 1, The gas containing methane (CH ₄ ) is a hydrogen gas production method comprising a gas generated in steel mills. The method according to claim 4, The gas containing methane (CH ₄ ) is a hydrogen gas production method comprising a coke oven gas (COG) generated during the coke dry distillation in the coke oven. The method according to claim 1, The method for producing hydrogen gas to methane (CH ₄₎ gas including the gas comprises at least methane (CH ₄₎ is 90%. The method according to claim 1, In the process of reacting the gas containing methane (CH ₄ ) and the carbon dioxide (CO ₂ ), Method for producing hydrogen gas in which carbon monoxide is produced. The method according to claim 7, Hydrogen gas production method comprising the step of separating the hydrogen gas and carbon monoxide gas. The method according to any one of claims 1 to 8, The steel slag is hydrogen gas production method using any one of the steel slag containing 5 wt% or more CaO and the steel slag containing 5 wt% or more magnesium compounds. The method according to claim 9, The process of generating carbon dioxide (CO ₂ ) using the steel slag, Preparing a solid comprising CaCO ₃ using steelmaking slag containing 5 wt% or more of CaO; And Separating carbon dioxide (CO ₂ ) from the solids; Hydrogen gas production method comprising a. The method according to claim 10, The process of manufacturing the solid, Preparing an aqueous solution by mixing the seasonal slag with water; And Blowing a gas containing carbon dioxide into the aqueous solution to prepare a solid containing CaCO ₃ ; Hydrogen gas production method comprising a. The method according to claim 10, In the process of separating carbon dioxide from the solid, And heat treating the solid to a temperature of 900 ° C. to 1200 ° C. to dissociate carbon dioxide from the solid. The method according to claim 9, The process of generating carbon dioxide (CO ₂ ) using the steel slag, Extracting the magnesium eluate by treating the steel slag containing 5 wt% or more of the magnesium compound with a solvent containing an acid; Hydrolyzing the magnesium eluate to produce a solid comprising a magnesium compound; And Separating carbon dioxide (CO ₂ ) from the solids; Hydrogen gas production method comprising a. The method according to claim 13, The process of extracting the magnesium eluate is A method for producing hydrogen gas, which extracts magnesium eluate by separating solid silicon dioxide (SiO ₂ ) from the steelmaking slag. The method according to claim 13, The process of manufacturing the solid, Hydrolyzing the magnesium eluate to prepare a magnesium hydroxide (Mg (OH) ₂ ) solution; And Preparing a solid magnesium carbonate (Mg (CO ₃ )) by injecting and carbonizing a gas containing carbon dioxide (CO ₂ ) into the magnesium hydroxide (Mg (OH) ₂ ) solution; Hydrogen gas production method comprising a. The method according to claim 13, The process of separating carbon dioxide (CO ₂ ) from the solids, And heat treating the solid to a temperature of 900 ° C. to 1200 ° C. to dissociate carbon dioxide from the solid. A carbon dioxide producing apparatus for producing carbon dioxide (CO ₂ ) using steel slag; A reaction apparatus for producing a gas containing hydrogen (H ₂ ) by reacting a gas including carbon dioxide (CO ₂ ) generated in the carbon dioxide manufacturing apparatus with methane (CH ₄ ); And Separation unit for separating the other gas outside the hydrogen (H _2), the hydrogen (H ₂₎ from the gas produced in the reaction device; Hydrogen gas production apparatus comprising a. The method according to claim 17, The reactor is a hydrogen gas production apparatus for reacting the carbon dioxide (CO ₂ ) and methane (CH ₄ ) at a temperature of 900 ℃ to 1100 ℃. The method according to claim 17, In the reaction apparatus, carbon monoxide (CO) is generated together with the hydrogen (H ₂ ), The separation device is a hydrogen gas production device for separating the hydrogen and carbon monoxide. The method according to any one of claims 17 to 19, The carbon dioxide manufacturing apparatus, An aqueous solution manufacturing unit for producing an aqueous solution by mixing the slag and the solvent; A solid production unit for preparing carbon solids by injecting carbon dioxide (CO ₂ ) gas into a product generated from the aqueous solution production unit; And Firing unit for separating the carbon dioxide (CO ₂ ) by firing the solid produced in the solid production apparatus; Hydrogen gas production apparatus comprising a.

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