JP5554537B2 - Paper catalyst and method for producing the same - Google Patents

Description

  The present invention relates to a paper catalyst applied to a reformer for forming hydrogen into a sheet and producing hydrogen by a reforming reaction, and a method for producing the paper catalyst.

  Recently, for example, city gas containing methane as a main component has been proposed to undergo a reforming reaction to produce hydrogen for use in household fuel cells. Conventionally, various paper-like catalysts have been proposed as a catalyst for this purpose (see, for example, Patent Document 1). Such a paper catalyst is made of a porous material obtained by a wet papermaking method, and since the metal catalyst component is previously incorporated in the paper, the reaction gas enters the pores, and It is considered that the reaction can efficiently proceed by reacting with the metal catalyst component in the pores. Further, the presence of the fiber network peculiar to the paper structure allows heat to spread throughout the reactor, thereby suppressing the occurrence of local and abrupt reactions and causing a mild reaction.

JP 2003-126705 A

  However, in the conventional paper catalyst, since it is necessary to add an inorganic binder component having high heat resistance in order to maintain the shape of the paper, for example, the catalyst component is nickel metal (Ni) or nickel metal (Ni). In the case of oxide particles containing, there is a problem that the inorganic binder component may hinder the catalytic reaction. In particular, since the oxide particles containing nickel metal (Ni) or nickel metal (Ni) can efficiently produce hydrogen by reforming a gas mainly composed of methane such as city gas, A paper catalyst capable of performing an efficient catalytic reaction while containing these catalyst components has been demanded.

  The present invention has been made in view of such circumstances, and a paper catalyst capable of efficiently producing hydrogen while using oxide particles containing nickel metal (Ni) or nickel metal (Ni) as a catalyst component, and the same. It is to provide a manufacturing method.

The invention according to claim 1 is a paper catalyst applied to a reformer for producing hydrogen by performing a steam reforming reaction of a gas containing methane as a main component while being formed into a sheet shape. A catalyst component composed of oxide particles containing nickel metal, a catalyst component, an inorganic binder, a pore regulator, and a heat-resistant fiber are mixed in a predetermined amount of water to form a slurry, and a flocculant is added to the slurry. after generating the floc Te, formed into a sheet by paper making the flock and fired, and a formed Ru multi porous catalyst structure of a heat-resistant fiber obtained by holding the catalyst component in the inorganic binder In addition, the porosity of the porous catalyst structure can be arbitrarily adjusted by mixing the pore adjuster and obtained through firing at a temperature of 1000 ° C. or higher. It is a sign.

The invention according to claim 2 is a method for producing a paper catalyst applied to a reformer for producing hydrogen by performing a steam reforming reaction of a gas containing methane as a main component while being formed into a sheet shape. A slurry generating step of generating a slurry by mixing a catalyst component made of nickel metal or oxide particles containing nickel metal, an inorganic binder, a pore regulator, and a heat-resistant fiber into a predetermined amount of water, and obtained in the slurry generating step A floc generating step for generating flocs by adding a flocculant to the resulting slurry, a sheet forming step for obtaining a sheet-like porous structure by papermaking the flocs obtained in the floc generating step, and the sheet forming step firing the obtained sheet-like porous structure in conjunction with a firing step of obtaining a sheet-shaped porous catalyst structure, this of mixing the pore controlling agent The porous be optionally adjusted porosity of the catalyst structure, and the firing step is characterized in that it is a 1000 ° C. or higher temperature by.

According to the first and second aspects of the invention, since firing is performed at a temperature of 1000 ° C. or higher, hydrogen is efficiently produced while using nickel metal (Ni) or oxide particles containing nickel metal (Ni) as a catalyst component. be able to.

Further , since the reformer produces hydrogen by subjecting a gas containing methane as a main component to a steam reforming reaction, nickel metal (Ni) or oxide particles containing nickel metal (Ni) are used as catalyst components. Thus, hydrogen can be produced more efficiently.

Furthermore , since the porosity of the porous catalyst structure is arbitrarily adjusted by the pore adjuster, the reaction efficiency of the catalyst can be improved while maintaining the moldability of the porous catalyst structure.

The flowchart which shows the manufacturing process of the paper catalyst which concerns on embodiment of this invention. It is an experimental result for showing the superiority of an embodiment of the present invention, and is a graph which shows methane conversion rate (%). It is an experimental result for showing the predominance of the embodiment of the present invention, and is a graph showing the result of XRD observation of Example 1 and Comparative Example 1 It is an experimental result for showing the predominance of the embodiment of the present invention, and is a graph showing the result of XRD observation of Example 2 and Comparative Example 2 It is an experimental result for showing the predominance of the embodiment of the present invention, and is a graph showing the result of XRD observation of Example 3 and Comparative Example 3 It is an experimental result for showing the predominance of the embodiment of the present invention, and is a graph showing the result of XRD observation of Example 4 and Comparative Example 4

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The paper catalyst according to this embodiment is composed of a sheet-like catalyst structure having catalyst components made of nickel metal or oxide particles containing nickel metal in the pores. As shown in FIG. It is manufactured through S1, flock generation step S2, sheeting step S3, drying step S4, and firing step S5. In addition, you may add the beating process which beats and unravels the organic fiber as a raw material before slurry production | generation process S1.

  The slurry generation step S1 includes a heat-resistant fiber (inorganic fiber or organic fiber), an inorganic filler, an inorganic binder (inorganic binder), a catalyst component (catalyst powder) made of oxide particles containing nickel metal or nickel metal, and pore adjustment. In this step, the agent is mixed in a predetermined amount of water and then sufficiently stirred with a stirrer or the like to produce a slurry in which the contents are uniformly dispersed. In addition to the above substances, various additives such as a pH adjusting agent may be contained in the slurry as necessary.

  The heat-resistant fiber needs to be chemically and physically stable, and preferably has strong entanglement between the fibers at the time of papermaking in the subsequent sheet forming step S3. That is, since the reaction temperature of the methane steam reforming reaction applied in the present embodiment is 500 to 800 ° C., the heat resistant fiber is required to be highly heat resistant and chemically stable. It is. For example, ceramic fiber, glass fiber, carbon fiber, etc. are mentioned.

  Examples of the inorganic filler include oxides such as alumina, forsterite, enstatite, spinel, silica, mullite, cordierite, zircon, aluminum titanate, magnesia, titania, zirconia, and hydroxides such as aluminum hydroxide and titanium hydroxide. , Carbonates such as calcium carbonate, viscosity of talc, clay, kaolinite, etc., kneaded paints such as black, titanium yellow, and pottery, or vanadium, chromium, manganese, iron, cobalt, nickel Examples thereof include metal oxides such as copper and tungsten, and oxides of rare earth elements such as cerium, protheodymium, neodymium, and samarium.

  The inorganic binder (inorganic binder) binds the heat-resistant fiber and the inorganic filler contained in the drying step S4 and the firing step S5, and retains the shape instead of the organic fiber after disappearing in the firing step S5. In addition, the heat-resistant fiber and the catalyst component are bonded together. As this inorganic binder, it is preferable to use, for example, colloidal silica, colloidal alumina, colloidal zirconia, and the like. If these are used, the resulting paper catalyst is excellent in dispersibility and the strength of the paper itself can be improved.

  The content of the inorganic binder is preferably 5 to 30%. This is because when the content exceeds 30%, the pores inherent to the paper are affected, and the reaction activity starts to decrease. When the content is less than 5%, sufficient sheet strength cannot be obtained. In addition to the inorganic binder, an organic binder (organic binder) may be added. This organic binder exerts a reinforcing effect on the sheet-like structure after paper making, and can improve the tensile strength and improve workability by addition.

  The catalyst powder (catalyst component) in the present embodiment is made of nickel metal (Ni) or oxide particles containing nickel metal (Ni). The nickel metal catalyst has a feature that shows high activity for the steam reforming catalytic reaction of methane, which is a main component of natural gas or city gas, and is chemisorbed on the surface of an inorganic oxide serving as a catalyst carrier. Therefore, it is preferably applied to a reformer for producing hydrogen by a reforming reaction.

  The pore adjuster is capable of arbitrarily adjusting the porosity in a sheet-like (paper-like) porous structure obtained in the sheet forming step described later. Such pore adjusters are generally used when adjusting the porosity of the nonwoven fabric, and include, for example, those made of natural diatomaceous earth, carbon fiber, graphite or the like.

  The floc generation step S2 is a step for generating flocs by adding a flocculant to the slurry obtained in the slurry generation step S1. In the present embodiment, two types of cationic polymer and anionic polymer are used. A polymer flocculant is used. By using these two polymer flocculants in combination, the yield of the manufactured sheet-like catalyst carrier structure can be significantly improved.

  The sheet forming step S3 is a step for obtaining a sheet-like porous structure by paper-making the flock obtained in the flock generating step S2, and obtaining a sheet shape having a uniform thickness through this step. Can do. The sheet forming step S3 is a general-purpose step for obtaining a sheet-like (paper-like) material by a wet papermaking method. The obtained sheet-like porous structure becomes a paper catalyst by being baked in the baking step S5 through the drying step S4. Note that a reduction step for performing hydrogen reduction may be added after the firing step S5.

  The firing step S5 is a step for firing the sheet-like porous structure obtained in the sheet forming step S3 to obtain a sheet-like catalyst structure. In the present embodiment, the firing step S5 is performed at a temperature of 1000 ° C. or higher. The baking step S5 is performed. According to this embodiment, since baking is performed at a temperature of 1000 ° C. or higher, hydrogen can be efficiently produced while using nickel metal (Ni) or oxide particles containing nickel metal (Ni) as a catalyst component.

  As mentioned above, the paper catalyst which concerns on this embodiment can be obtained by passing through a series of processes. According to the present embodiment, since a sheet-like paper catalyst is obtained by the catalyst internal addition method in the wet papermaking method, it is sufficient to contain mineral fibers in the slurry generated at the slurry generation step S1, so that existing equipment is sufficient. (Manufacturing equipment using a wet papermaking method) can be used.

  Further, in the present embodiment, it is applied to a reformer that is formed into a sheet shape and produces hydrogen by a reforming reaction, and the particularly applied reformer has methane as a main component. Hydrogen is produced by subjecting the contained gas to a steam reforming reaction. Thus, since the reformer is for producing hydrogen by subjecting a gas containing methane as a main component (city gas) to a steam reforming reaction, it contains nickel metal (Ni) or nickel metal (Ni). Hydrogen can be produced more efficiently while using oxide particles as a catalyst component. Although city gas differs slightly depending on the gas supply company, it usually contains 80 to 90% methane.

Furthermore, according to this embodiment, since the porosity of the porous catalyst structure is arbitrarily adjusted by the pore adjuster, the reaction efficiency of the catalyst is improved while maintaining the moldability of the porous catalyst structure. Can do. Incidentally, input amount of pore modifiers, depending on the reforming performance required by applicable reformer, is favored arbitrary to arbitrary adjust the porosity of the porous catalyst structure.

Next, more specific examples of the present invention will be described. Of course, the present invention is not limited to these examples, and can be arbitrarily changed or added.
(Example)
The oxide particles (10% Ni / Al ₂ O ₃ ) containing nickel metal are used as the catalyst component (0.2138 (g)), and the slurry generation step S1, the flock generation step S2, the sheeting step S3, and the drying step S4. Then, a paper-like catalyst (paper catalyst) was obtained through the firing step S5 and the reduction step (4 hours at 800 ° C.). Firing in the firing step S5 was performed at a temperature of 1000 ° C. for 4 hours.

  However, a paper catalyst (Example 1) containing a silica-based binder (fine silica) and having a weight (including a catalyst component) of 0.8611 (g), and containing a zirconia-based binder and having a weight (including a catalyst component) of 0 5481 (g) of paper catalyst (Example 2), containing a silica-based binder (normal particle size) and having a weight (including catalyst components) of 0.7760 (g), Paper catalysts (Example 4) each containing an alumina binder (fine silica) and having a weight (including catalyst components) of 0.8802 (g) were prepared.

(Comparative example)
The oxide particles (10% Ni / Al ₂ O ₃ ) containing nickel metal are used as the catalyst component (0.2138 (g)), and the slurry generation step S1, the flock generation step S2, the sheeting step S3, and the drying step S4. Then, a paper-like catalyst (paper catalyst) was obtained through the firing step S5 and the reduction step (4 hours at 800 ° C.). Firing in the firing step S5 was performed at a temperature of 600 ° C. for 4 hours.

  However, a paper catalyst (Comparative Example 1) containing a silica-based binder (fine silica) and having a weight (including catalyst component) of 0.897 (g), and containing a zirconia-based binder and having a weight (including catalyst component) of 0. 6138 (g) of paper catalyst (Comparative Example 2), a silica-based binder (normal particle size) and a weight (including catalyst component) of 0.7923 (g) of paper catalyst (Comparative Example 3), silica Paper catalysts (comparative example 4) each containing an alumina binder (fine silica) and having a weight (including catalyst component) of 0.9178 (g) were prepared.

(Experiment 1)
Experiments were conducted to pass the methane gas through Examples 1 to 4 and Comparative Examples 1 to 4 and evaluate the performance. However, the experiment conditions were set to SV: 5000h-1, S / C (Steam / Carbon): 3, and the relationship between the reaction temperature (° C.) and the methane conversion rate (%) was tested. The experimental results are shown in FIG. From these experimental results, it can be seen that this example has a high methane conversion rate (%) at any reaction temperature and can constitute a high-performance reformer. Moreover, it turns out that the thing of a present Example (especially Example 1, 3, 4) can aim at methane conversion also in the low temperature range (less than 600 degreeC) compared with the thing of a comparative example.

(Experiment 2)
When SEM observation was performed on Example 4 and Comparative Example 4, it was confirmed that the surface of the catalyst component (Ni / Al ₂ O ₃ catalyst) was covered with amorphous SiO ₂ in Comparative Example 4. was, but that of example 4, amorphous SiO ₂ covering the surface of the catalyst components (Ni / _Al 2 _{O 3} catalyst) was not observed, the catalyst component (Ni / _Al 2 _{O 3} catalyst) uniformly exposed It was suggested that the Thereby, it can be seen that Example 4 is a paper catalyst having a higher methane conversion rate than that of Comparative Example 4.

(Experiment 3)
When the XRD observation of Examples 1 to 4 and Comparative Examples 1 to 4 was performed, the results of FIGS. 3 to 6 were obtained. Symbol A in these figures shows a waveform indicating the crystal structure, and it can be seen that crystallization is progressing in any of the examples. Thereby, it can be seen that Example 4 is a paper catalyst having a higher methane conversion rate than that of Comparative Example 4.

A catalyst component composed of nickel metal or oxide particles containing nickel metal, and the catalyst component, an inorganic binder, a pore regulator, and a heat-resistant fiber are mixed in a predetermined amount of water to form a slurry, and the flocculant is added to the slurry. And a porous catalyst structure comprising heat-resistant fibers in which the catalyst component is held by an inorganic binder by paper making, forming the floc into a sheet, and firing. In addition, the porosity of the porous catalyst structure is arbitrarily adjusted by mixing the pore regulator, and if it is a paper catalyst obtained through calcination at a temperature of 1000 ° C. or higher, and its production method, Other forms may be used.

S1 Slurry production process S2 Flock production process S3 Sheeting process S4 Drying process S5 Firing process

Claims (2)

In a paper catalyst applied to a reformer for producing hydrogen by performing a steam reforming reaction of a gas containing methane as a main component while being formed into a sheet shape,
A catalyst component consisting of nickel metal or oxide particles containing nickel metal;
The catalyst component, the inorganic binder, the pore regulator, and the heat-resistant fiber are mixed in a predetermined amount of water to form a slurry, and after adding flocculant to the slurry to form a floc, paper making the floc formed into a sheet and fired, a multi-porous catalyst structure Ru consists heat-resistant fiber obtained by holding the catalyst component in an inorganic binder,
The paper catalyst is characterized in that the porosity of the porous catalyst structure is arbitrarily adjusted by mixing the pore-regulating agent and obtained by firing at a temperature of 1000 ° C. or higher. In a method for producing a paper catalyst applied to a reformer for producing hydrogen by performing a steam reforming reaction of a gas containing methane as a main component while being formed into a sheet shape,
A slurry generating step of generating a slurry by mixing a catalyst component comprising nickel metal or oxide particles containing nickel metal, an inorganic binder, a pore regulator, and a heat-resistant fiber into a predetermined amount of water;
A floc generating step of adding flocculant to the slurry obtained in the slurry generating step to generate floc;
A sheet forming step of obtaining a sheet-like porous structure by paper-making the floc obtained in the flock generation step;
A firing step of firing the sheet-like porous structure obtained in the sheeting step to obtain a sheet-like porous catalyst structure;
And a porosity of the porous catalyst structure is arbitrarily adjusted by mixing the pore regulator, and the calcination step is performed at a temperature of 1000 ° C. or higher. Manufacturing method.

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