JP7353751B2 - Fischer-Tropsch synthesis catalyst structure, method for producing the same, and method for producing hydrocarbons using the catalyst structure - Google Patents

Description

The present invention relates to a Fischer-Tropsch synthesis catalyst structure (hereinafter sometimes referred to as "FT synthesis catalyst structure" or "catalyst structure"), a method for producing the same, and production of hydrocarbons using the catalyst structure. Regarding the method.

As a method for producing hydrocarbon compounds that are used as raw materials for liquid fuel products such as synthetic oil and synthetic fuel, which are alternative fuels to petroleum, catalytic reactions are used to produce carbon monoxide gas (CO) and hydrogen gas (H Fischer-Tropsch synthesis reaction (hereinafter sometimes referred to as "FT synthesis reaction") is known, which synthesizes hydrocarbons, especially liquid hydrocarbons, from synthesis gas containing ₂ ) as the main component. As a catalyst used in this FT synthesis reaction, for example, Patent Document 1 discloses a catalyst in which active metals such as cobalt and iron are supported on a carrier such as silica and alumina, and Patent Document 2 discloses a catalyst in which active metals such as cobalt and iron are supported on a carrier such as silica and alumina. , zirconium or titanium, and silica are disclosed.

The catalyst used in the FT synthesis reaction can be prepared by impregnating a carrier such as silica or alumina with a cobalt salt, a ruthenium salt, etc., and then firing the impregnated carrier to prepare a catalyst (on which cobalt oxide and/or ruthenium oxide is supported). (unreduced catalyst). In order for the catalyst obtained in this way to exhibit sufficient activity for the FT synthesis reaction, as disclosed in Patent Document 3, the catalyst is brought into contact with a reducing gas such as hydrogen gas and subjected to a reduction treatment. However, it is necessary to convert the active metals cobalt and/or ruthenium from an oxide state to a metal state.

By the way, since the FT synthesis reaction is accompanied by extremely large heat generation as disclosed in Patent Document 4, overheated parts of the catalyst surface become hot spots, and side reactions ( It is known that the progress of carbonaceous precipitation (e.g. carbonaceous precipitation) reduces activity. In order to prevent the formation of such hot spots, it is necessary to disperse the active sites without agglomerating fine particles of active metal species (metal fine particles), which are functional substances that act as catalysts. In order to prevent the fine particles of the active metal species from aggregating, it is conceivable to use a carrier that has a strong interaction with the active metal species to prevent the metal fine particles from easily aggregating with each other.

As an example of this method, a sol-gel method is known in which fine metal particles are supported in a highly dispersed manner. In the sol-gel method, active metal species are uniformly introduced at the atomic level during the synthesis of the metal oxide that serves as the carrier. Since the active metal species of the supported metal catalyst are highly dispersed in the lattice of the metal oxide that is the carrier, they do not easily aggregate during various treatments and reactions. However, since the active metal species is strongly bound to the carrier, it becomes difficult to activate the catalyst prior to the reaction, resulting in a problem that sufficient catalytic activity cannot be obtained.

Further, when metal fine particles agglomerate, the effective surface area of the catalyst decreases, resulting in a decrease in catalytic activity, and thus the life of the catalyst itself becomes shorter than normal. Therefore, the catalyst itself has to be replaced and regenerated in a short period of time, which makes the replacement work complicated and there is also the problem that resource saving cannot be achieved.

Further, Patent Document 5 describes that the decrease in activity of the catalyst used in the FT synthesis reaction is likely to be due to factors such as coke (carbon) deposition. As is clear from this, when used in the FT synthesis reaction, the catalyst structure has a small increase in coke amount due to coke deposition on the catalyst surface, high catalytic activity, and high product selectivity. It has been demanded.

Japanese Patent Application Publication No. 4-227847 Japanese Unexamined Patent Publication No. 59-102440 International Publication No. 2015/072573 Japanese Patent Application Publication No. 2000-70720 Japanese Patent Application Publication No. 2011-183282

The purpose of the present invention is to prevent fine particles of functional substances from agglomerating with each other, suppress the decline in catalyst activity, and extend the life of the catalyst. A Fischer-Tropsch synthesis catalyst structure and method for producing the same, which suppresses the production of coke and reduces the amount of coke deposited on the catalyst surface, and production of hydrocarbons using the catalyst structure. The purpose is to provide a method.

As a result of intensive research to achieve the above object, the present inventors have discovered that an FT synthesis catalyst structure includes a carrier with a porous structure composed of a zeolite type compound, and at least one function inherent in the carrier. the carrier has a passage communicating with each other, the carrier contains aluminum and silicon, and the atomic ratio of Si/Al contained in the carrier is 2.0 or more. By the presence of the functional substance in at least the passage of the carrier, it is possible to prevent fine particles of the functional substance from aggregating with each other, suppress a decrease in catalyst activity, and achieve a longer life. It was discovered that a catalyst structure capable of reducing the production or adhesion of coke could be obtained, and the present invention was completed based on this knowledge.

That is, the gist of the present invention is as follows.
[1] At least a carrier with a porous structure composed of a zeolite type compound,
at least one functional substance inherent in the carrier;
Equipped with
The carrier contains aluminum (Al) and silicon (Si),
The ratio of silicon (Si) to aluminum (Al) (atomic ratio Si/Al) contained in the carrier is 2.0 or more,
the carrier has passages that communicate with each other,
A Fischer-Tropsch synthesis catalyst structure, characterized in that the functional substance has a property of preventing coke from forming or adhering, and is present in at least the passageway of the carrier.
[2] The catalyst structure has a coke amount of less than 1.0% by mass after carrying out a Fischer-Tropsch synthesis reaction at a reaction temperature of 700° C. for 1 hour using a normal pressure flow reactor. The Fischer-Tropsch synthesis catalyst structure described in [1].
[3] The passageway is one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the skeletal structure of the zeolite-type compound, and one of the one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the skeletal structure of the zeolite-type compound. The Fischer-Tropsch synthesis catalyst structure according to the above [1] or [2], wherein the Fischer-Tropsch synthesis catalyst structure has an enlarged diameter portion different from any of the enlarged diameter portions, and the functional substance is present at least in the enlarged diameter portion.
[4] The expanded diameter portion communicates with each other a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Tropsch synthesis catalyst structure.
[5] The Fisher according to [3] or [4] above, wherein the average particle diameter of the functional substance is larger than the average inner diameter of the passageway and smaller than or equal to the inner diameter of the enlarged diameter portion.・Tropsch synthesis catalyst structure.
[6] The above [1], wherein the metal element (M) of the functional substance is contained in an amount of 0.5 to 2.5% by mass based on the Fischer-Tropsch synthesis catalyst structure. The Fischer-Tropsch synthesis catalyst structure according to any one of ~[5].
[7] The functional structure according to any one of [1] to [6] above, wherein the functional substance is a metal oxide fine particle.
[8] The functional structure according to any one of [1] to [6] above, wherein the functional substance is a metal fine particle.
[9] The metal fine particles contain one or more metals or alloys selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni), or ruthenium (Ru). , the Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [8] above.
[10] The Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [9] above, wherein the functional substance has an average particle size of 0.08 nm to 30 nm.
[11] The method according to any one of [1] to [10] above, wherein the ratio of the average particle diameter of the functional substance to the average inner diameter of the passage is 0.05 to 300. Fischer-Tropsch synthesis catalyst structure.
[12] The Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [11] above, wherein the passage has an average inner diameter of 0.1 nm to 1.5 nm.
[13] The Fischer-Tropsch synthesis catalyst structure according to any one of [3] to [12] above, wherein the expanded diameter portion has an inner diameter of 0.5 nm to 50 nm.
[14] The Fischer-Tropsch synthesis catalyst according to any one of [1] to [13] above, further comprising at least one other functional substance held on the outer surface of the carrier. Structure.
[15] The content of the at least one functional substance inherent in the carrier is higher than the content of the at least one other functional substance held on the outer surface of the carrier. The Fischer-Tropsch synthesis catalyst structure described in [14] above.
[16] The Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [15] above, wherein the zeolite type compound is a silicate compound.
[17] A hydrocarbon production apparatus having the Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [16] above.
[18] A firing step of firing a precursor material (B) in which the precursor material (A) is impregnated with a metal-containing solution to obtain a carrier with a porous structure composed of a zeolite type compound;
a hydrothermal treatment step of hydrothermally treating the precursor material (C) obtained by firing the precursor material (B);
A method for producing a Fischer-Tropsch synthesis catalyst structure, comprising:
The precursor material (A) contains aluminum (Al) and silicon (Si),
The catalyst structure is obtained by preparing the precursor material (A) so that the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) is 2.0 or more. A method for producing a characteristic Fischer-Tropsch synthesis catalyst structure.
[19] The Fischer surfactant according to the above [18], characterized in that 50 to 500% by mass of a nonionic surfactant is added to the precursor material (A) before the firing step. A method for producing a Tropsch synthesis catalyst structure.
[20] Before the firing step, the metal-containing solution is added to the precursor material (A) in multiple portions to impregnate the precursor material (A) with the metal-containing solution. The method for producing a Fischer-Tropsch synthesis catalyst structure as described in [18] or [19] above.
[21] When impregnating the precursor material (A) with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) The atomic ratio (Si/M ratio) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to (A) is 10 to 1000. The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of [18] to [20] above, characterized in that the structure is adjusted so that
[22] The Fischer-Tropsch synthesis according to any one of [18] to [21] above, characterized in that in the hydrothermal treatment step, the precursor material (C) and a structure directing agent are mixed. Method for manufacturing catalyst structure.
[23] The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of [18] to [22] above, wherein the hydrothermal treatment step is performed in a basic atmosphere.
[24] The Fischer-Tropsch synthesis catalyst according to any one of [18] to [23] above, further comprising a step of subjecting the hydrothermally treated precursor material (C) to a reduction treatment. Method of manufacturing the structure.
[25] A method for producing hydrocarbons in which hydrocarbons are synthesized from carbon monoxide and hydrogen using a catalyst, the catalyst comprising:
A carrier with a porous structure composed of a zeolite type compound,
at least one functional substance inherent in the carrier,
The carrier contains aluminum (Al) and silicon (Si),
The atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) contained in the carrier is 2.0 or more,
the carrier has passages that communicate with each other,
The functional substance is characterized in that it has a property of being less likely to generate or adhere to coke, and includes a Fischer-Tropsch synthesis catalyst structure that is present in at least the enlarged diameter portion of the passageway of the carrier. A method for producing hydrocarbons.

According to the present invention, it is possible to prevent fine particles of a functional substance from agglomerating with each other, to suppress a decrease in catalyst activity, and to extend the life of the catalyst. A Fischer-Tropsch synthesis catalyst structure and method for producing the same, which suppresses the production of coke and reduces the amount of coke deposited on the catalyst surface, and production of hydrocarbons using the catalyst structure. method can be provided.

FIG. 1 schematically shows the internal structure of a Fischer-Tropsch synthesis catalyst structure according to an embodiment of the present invention, and FIG. 1(a) is a perspective view (partially shown in cross section). ), FIG. 1(b) is a partially enlarged sectional view. FIG. 2 is a partially enlarged sectional view for explaining an example of the function of the Fischer-Tropsch synthesis catalyst structure in FIG. It is a diagram. FIG. 3 is a flowchart showing an example of a method for manufacturing the Fischer-Tropsch synthesis catalyst structure of FIG. FIG. 4 is a schematic diagram showing a modification of the Fischer-Tropsch synthesis catalyst structure of FIG. 1.

Embodiments of the present invention will be described in detail below with reference to the drawings.

[Configuration of Fischer-Tropsch synthesis catalyst structure]
FIG. 1 is a diagram schematically showing the configuration of a Fischer-Tropsch synthesis catalyst structure (hereinafter also simply referred to as "catalyst structure") according to an embodiment of the present invention, and (a) is a perspective view (partially ), (b) is a partially enlarged sectional view. Note that the catalyst structure shown in FIG. 1 shows an example thereof, and the shape, dimensions, etc. of each structure according to the present invention are not limited to those shown in FIG. 1.

As shown in FIG. 1(a), the catalyst structure 1 includes a carrier 10 having a porous structure made of a zeolite type compound, and at least one functional substance 20 inherent in the carrier 10.

In the catalyst structure 1 , a plurality of functional substances 20 , 20 , . . . are included inside the porous structure of the carrier 10 . The functional substance 20 is a catalytic substance having catalytic ability (catalytic activity) at least during use, and has the form of fine particles. The functional substance will be described in detail later. Further, the functional substance 20 may be particles containing a metal, a metal oxide, a metal alloy, or a composite material thereof.

The carrier 10 has a porous structure, and preferably has a plurality of pores 11a, 11a, . . . , so as to have passages 11 that communicate with each other, as shown in FIG. 1(b). Here, the functional substance 20 is present in at least the passages 11 of the carrier 10, and is preferably retained in at least the passages 11 of the carrier 10.

With this configuration, movement of the functional substance 20 within the carrier 10 is regulated, and aggregation of fine particles of the functional substances 20, 20 is effectively prevented. As a result, the reduction in the effective surface area of the functional material 20 can be effectively suppressed, and the catalytic activity of the functional material 20 can be maintained for a long period of time. That is, according to the catalyst structure 1, a decrease in catalyst activity due to aggregation of fine particles of the functional substance 20 can be suppressed, and the life of the catalyst structure 1 can be extended. Furthermore, by extending the life of the catalyst structure 1, the frequency of replacing the catalyst structure 1 can be reduced, and the amount of discarded used catalyst structures 1 can be significantly reduced, leading to resource conservation. .

Normally, when a catalyst structure is used in a fluid (for example, heavy oil or reformed gas such as NOx), there is a possibility that it will receive external force from the fluid. In this case, if the functional substance is merely held in an adhered state on the outer surface of the carrier 10, there is a problem that it is likely to separate from the outer surface of the carrier 10 due to the influence of external force from the fluid. On the other hand, in the catalyst structure 1, the functional substance 20 is present at least in the passage 11 of the carrier 10, so the functional substance 20 is difficult to separate from the carrier 10 even if it is affected by an external force caused by a fluid. . That is, when the catalyst structure 1 is in a fluid, the fluid flows into the passage 11 from the hole 11a of the carrier 10, so the speed of the fluid flowing inside the passage 11 is changed by the passage resistance (frictional force). It is considered that the speed is slower than the speed of the fluid flowing on the outer surface of the carrier 10. Due to the influence of such flow path resistance, the pressure that the functional substance 20 held in the passage 11 receives from the fluid is lower than the pressure that the functional substance receives from the fluid outside the carrier 10. Therefore, detachment of the functional substance 20 contained in the carrier 10 can be effectively suppressed, and the catalytic activity of the functional substance 20 can be stably maintained over a long period of time. Note that the flow path resistance as described above is considered to increase as the passage 11 of the carrier 10 has a plurality of bends and branches and the interior of the carrier 10 has a more complex three-dimensional structure. .

Further, the carrier 10 is a zeolite type compound containing aluminum (Al) and silicon (Si), and the value of the atomic ratio (Si/Al ratio) of silicon (Si) to aluminum (Al) contained in the carrier 10. is 2.0 or more. By using a zeolite type compound with a high proportion of silicon (Si) as the carrier 10, when the catalyst structure is used in an FT synthesis reaction, the catalyst structure 1 Since the increase in the amount of coke can be suppressed, the life of the FT synthesis catalyst structure can be extended, and the frequency of regeneration treatment for the FT synthesis catalyst structure can be reduced. Such an effect is thought to be due to the weakening of the effect of the solid acid derived from the zeolite type compound constituting the carrier 10, thereby suppressing the oligomerization reaction of hydrocarbons. From this point of view, the value of the Si/Al ratio in the carrier 10 is preferably 5.0 or more, more preferably 8.0 or more. On the other hand, the upper limit of the Si/Al ratio in the carrier 10 may be infinite (that is, it contains a trace amount of aluminum (Al)), but for example, from the viewpoint of manufacturing efficiency, the upper limit may be set to 10 ⁹ . , the upper limit may be set to 10 ⁶ from the viewpoint of exhibiting the action of aluminum (Al) as a solid acid. Among these, the Si/Al ratio is preferably less than 50 from the viewpoint of increasing the selectivity of the product.

Moreover, the passage 11 is formed of one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the skeleton structure of the zeolite-type compound, and one of the one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the skeletal structure of the zeolite-type compound. It is preferable that the functional substance 20 has an enlarged diameter part 12 that is different from either of them. It is more preferable to be present. Further, it is preferable that the enlarged diameter portion 12 communicates with each other a plurality of holes 11a, 11a constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. As a result, separate passages different from the one-dimensional pores, two-dimensional pores, or three-dimensional pores are provided inside the carrier 10, so that the functions of the functional substance 20 can be more fully exhibited. Note that the one-dimensional hole referred to here refers to a tunnel-type or cage-type hole forming a one-dimensional channel, or a plurality of tunnel-type or cage-type holes (multiple holes forming a plurality of one-dimensional channels). one-dimensional channel). Furthermore, a two-dimensional hole refers to a two-dimensional channel in which multiple one-dimensional channels are two-dimensionally connected, and a three-dimensional hole refers to a three-dimensional channel in which a plurality of one-dimensional channels are three-dimensionally connected. Point. Thereby, movement of the functional substance 20 within the carrier 10 is further restricted, and separation of the functional substance 20 and aggregation of fine particles of the functional substances 20 and 20 can be further effectively prevented. Inclusion refers to a state in which the functional substance 20 is encapsulated in the carrier 10. At this time, the functional substance 20 and the carrier 10 do not necessarily need to be in direct contact with each other, and other substances (for example, a surfactant, etc.) may be present between the functional substance 20 and the carrier 10. The functional substance 20 may be indirectly held on the carrier 10 in this state.

Although FIG. 1(b) shows a case where the functional substance 20 is included in the enlarged diameter part 12, the present invention is not limited to this configuration. It may be held in the passage 11 in a state that it protrudes outside of the passage 12 . Further, the functional substance 20 may be partially embedded in a portion of the passage 11 other than the enlarged diameter portion 12 (for example, an inner wall portion of the passage 11), or may be held by fixation or the like.

Furthermore, the passage 11 is three-dimensionally formed inside the carrier 10, including a branching part or a merging part, and the enlarged diameter part 12 is preferably provided at the branching part or the merging part of the passage 11. .

The average inner diameter _DF of the passages 11 formed in the carrier 10 is calculated from the average value of the short axis and long axis of the holes 11a constituting any one of the one-dimensional holes, two-dimensional holes, and three-dimensional holes, for example. It is 0.1 nm to 1.5 nm, preferably 0.5 nm to 0.8 nm. Further, the inner diameter D _E of the enlarged diameter portion 12 is, for example, 0.5 nm to 50 nm, preferably 1.1 nm to 40 nm, and more preferably 1.1 nm to 3.3 nm. The inner diameter D _E of the enlarged diameter portion 12 depends on, for example, the pore diameter of the precursor material (A) described later and the average particle diameter D _C of the functional substance 20 to be included. The inner diameter _DE of the enlarged diameter portion 12 is large enough to include the functional substance 20.

The carrier 10 is composed of a zeolite type compound. Examples of zeolite-type compounds include zeolite (aluminosilicate), cation exchange zeolite, silicate compounds such as silicalite, zeolite analogs such as aluminoborate, aluminoarsenate, and germanate, molybdenum phosphate, etc. Examples include phosphate-based zeolite-like substances. Among these, the zeolite type compound is preferably a silicate compound, and more specifically, it is preferably a zeolite or a silicalite.

The skeleton structures of zeolite compounds are FAU type (Y type or X type), MTW type, MFI type (ZSM-5), FER type (ferrierite), LTA type (A type), and MWW type (MCM-22). , MOR type (mordenite), LTL type (L type), BEA type (beta type), etc., preferably MFI type, MOR type, BEA type, and more preferably MFI type. A zeolite type compound has a plurality of pores with a pore diameter depending on each skeleton structure. For example, the maximum pore diameter of the MFI type is 0.636 nm (6.36 Å), and the average pore diameter is 0.560 nm (5.60 Å). be.

The functional substance 20 has the form of fine particles, and may be primary particles or secondary particles formed by agglomeration of primary particles. The diameter D _C is preferably larger than the average inner diameter D _F of the passage 11 and less than or equal to the inner diameter D _E of the enlarged diameter portion 12 (D _F <D _C ≦D _E ). Such a functional substance 20 is preferably present in the enlarged diameter portion 12 within the passage 11, and movement of the functional substance 20 within the carrier 10 is restricted. Therefore, even if the functional substance 20 receives an external force from the fluid, movement of the functional substance 20 within the carrier 10 is suppressed, and the enlarged diameter portions 12, 12 distributed in the passage 11 of the carrier 10 are suppressed. It is possible to effectively prevent the functional substances 20, 20, . . . present in each of the functional substances 20, 20, .

Further, the average particle diameter D _C of the fine particles of the functional substance 20 is preferably 0.08 nm to 30 nm, more preferably 0.1 nm or more and less than 25 nm, for both primary particles and secondary particles. More preferably, it is 0.4 nm to 11.0 nm, particularly preferably 0.8 nm to 2.7 nm. Further, the ratio of the average particle diameter D _C of the functional substance 20 to the average inner diameter D _F of the passage 11 (D _C /D _F ) is preferably 0.05 to 300, more preferably 0.1 to 30. It is more preferably 1.1 to 30, particularly preferably 1.4 to 3.6. Further, it is preferable that the metal element (M) of the functional substance 20 is contained in an amount of 0.5 to 2.5% by mass based on the catalyst structure 1, and 0.5 to 2.5% by mass relative to the catalyst structure 1. More preferably, the content is 1.5% by mass. For example, when the metal element (M) is Co, the content (mass%) of the Co element is expressed as {(mass of Co element)/(mass of all elements in catalyst structure 1)}×100 .

The functional substance 20 may include a metal made of one kind of metal element, a mixture of two or more kinds of metal elements, or metal fine particles in which at least some of them are alloyed. Further, the functional substance 20 may include metal oxide fine particles made of an oxide of one or more metal elements or a composite material thereof. In addition, in this specification, "metal" (as a material) constituting a functional substance when used as a catalyst refers to a single metal containing one type of metal element (M) and a metal containing two or more types of metal elements (M). It is a general term for metals containing one or more metal elements.

Examples of metal elements contained in metal fine particles and metal oxide fine particles include platinum (Pt), palladium (Pd), ruthenium (Ru), nickel (Ni), cobalt (Co), molybdenum (Mo), and tungsten (W). , iron (Fe), chromium (Cr), cerium (Ce), copper (Cu), magnesium (Mg), aluminum (Al), etc., and it is preferable that one or more of the above is the main component. , cobalt, iron, nickel, and ruthenium, more preferably cobalt, iron, and nickel, and particularly preferably cobalt. In particular, it is preferable that the metal fine particles contain one or more metals or alloys selected from the group consisting of cobalt, iron, nickel, and ruthenium. Moreover, it is preferable that the metal oxide fine particles contain one or more metal elements selected from the group consisting of cobalt, iron, and nickel.

Further, the ratio of silicon (Si) constituting the carrier 10 to the total of the metal elements (M) constituting the functional substance 20 (atomic ratio Si/M) is preferably 10 to 1000, and 50 to More preferably, it is 200. If the ratio is greater than 1,000, the functional substance may not be able to function sufficiently as a catalyst, such as low activity. On the other hand, if the ratio is smaller than 10, the ratio of the functional substance 20 becomes too large, and the strength of the carrier 10 tends to decrease. Note that the functional substance 20 herein refers to fine particles held or supported inside the carrier 10, and does not include the functional substance attached to the outer surface of the carrier 10.

[Function of FT synthesis catalyst structure]
As described above, the catalyst structure 1 includes a carrier 10 having a porous structure and at least one functional substance 20 inherent in the carrier. The catalyst structure 1 exhibits the catalytic ability of the functional substance 20 when the functional substance 20 contained in the carrier comes into contact with a fluid. Specifically, the fluid that has come into contact with the outer surface 10a of the catalyst structure 1 flows into the carrier 10 through the holes 11a formed in the outer surface 10a, is guided into the passage 11, and moves through the passage 11. , exits to the outside of the catalyst structure 1 through the other hole 11a. In the course of movement of the fluid through the passageway 11, the fluid comes into contact with the functional substance 20 present in the passageway 11, thereby causing a catalytic reaction by the functional substance 20 having catalytic activity. Further, the catalyst structure 1 has molecular sieving ability due to the porous structure of the carrier.

First, the molecular sieving ability of the catalyst structure 1 will be explained using FIG. 2(a). As shown in FIG. 2(a), molecules 15a having a size smaller than or equal to the pore diameter of the pore 11a, in other words, smaller than the inner diameter of the passageway 11, can penetrate into the carrier 10. On the other hand, molecules 15b having a size exceeding the pore diameter of the pores 11a cannot penetrate into the carrier 10. In this way, when the fluid contains multiple types of compounds, the reaction of the compounds that cannot penetrate into the carrier 10 is regulated, and the compounds that can penetrate into the carrier 10 can be allowed to react.

Of the compounds produced within the carrier 10 by the reaction, only compounds composed of molecules having a size smaller than the pore diameter of the pores 11a can exit the carrier 10 through the pores 11a and are obtained as reaction products. On the other hand, compounds that cannot exit from the carrier 10 through the pores 11a can be released from the carrier 10 by converting them into compounds composed of molecules of a size that allows them to exit from the carrier 10. . In this way, by using the catalyst structure 1, a specific reaction product can be selectively obtained.

In the catalyst structure 1, the functional substance 20 is included in the enlarged diameter portion 12 of the passage 11, as shown in FIG. 2(b). When the average particle diameter D _C of the functional substance is larger than the average inner diameter D _F of the passage 11 and smaller than the inner diameter D _E of the enlarged diameter portion 12 (D _F < D _C < D _E ), the functional substance A small passage 13 is formed between the enlarged diameter portion 12 and the enlarged diameter portion 12 . Then, as shown by the arrow in FIG. 2(b), the fluid that has entered the small passageway 13 comes into contact with the functional substance. Since each functional substance is included in the enlarged diameter portion 12, movement within the carrier 10 is restricted. This prevents aggregation of fine particles of the functional substance within the carrier 10. As a result, a large contact area between the functional substance and the fluid can be stably maintained.

In particular, by setting the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) in the carrier 10 to 2.0 or more, it is possible to prevent the generation of coke in the FT synthesis reaction and the transfer of coke to the carrier 10. It is possible to suppress an increase in the amount of coke in the catalyst structure 1 due to the adhesion of. Such an effect is achieved by improving the crystallinity of the zeolite type compound constituting the carrier 10 and stabilizing the inclusion state of the functional substance 20 by the zeolite type compound, so that the functional substance 20 can be contained even in a high temperature environment. This is thought to be due to the fact that aggregation of fine particles is effectively suppressed. Here, the amount of coke in the catalyst structure 1 after performing the FT synthesis reaction is as follows: 70 mg of the catalyst structure is packed into a normal pressure flow reactor, hydrogen (8 ml/min) and carbon monoxide (4 ml/min) The temperature was raised at a rate of 20°C/min in the temperature range of 100 to 700°C while adjusting the pressure inside the apparatus to 0.1 MPa, and then the temperature was maintained at a reaction temperature of 700°C for 1 hour. The amount of carbon (C) produced after the Fischer-Tropsch synthesis reaction is preferably less than 1% by mass, more preferably less than 0.5% by mass, and more preferably less than 0.3% by mass. It is even more preferable.

Specifically, when molecules that have entered the passageway 11 come into contact with the functional substance 20, the molecules (substance to be modified) are modified by a catalytic reaction. In the present invention, by using the catalyst structure 1, for example, using a mixed gas mainly composed of hydrogen and carbon monoxide as a raw material, hydrocarbons (excluding _CH4 ), preferably having a carbon number of 2 or more and 20 or less hydrocarbons, more preferably olefins having 2 to 20 carbon atoms or aromatic hydrocarbons having 6 to 20 carbon atoms. According to the catalyst structure 1 of the present invention, it is also possible to produce hydrocarbons containing especially lower (C ₂ to C ₄ ) hydrocarbons, and hydrocarbons containing more olefins than paraffins can be produced. can also be manufactured. This catalytic reaction is carried out at a high temperature of, for example, 180° C. to 350° C., but since the functional substance 20 is inherent in the carrier 10, it is not easily affected by heating. In particular, since the functional substance 20 is present in the enlarged diameter portion 12, the movement of the functional substance 20 within the carrier 10 is further restricted, and aggregation (sintering) of the functional substances 20 is further suppressed. Ru. As a result, the decrease in catalyst activity is further suppressed, and the life of the catalyst structure 1 can be further extended.

[Method for manufacturing FT synthesis catalyst structure]
FIG. 3 is a flowchart showing a method for manufacturing the catalyst structure 1 of FIG.

(Step S1: Preparation process)
As shown in FIG. 3, first, a precursor material (A) for obtaining a carrier having a porous structure composed of a zeolite type compound is prepared. Precursor material (A) is preferably a regular mesoporous material, and can be appropriately selected depending on the type (composition) of the zeolite compound constituting the carrier of the catalyst structure.

Here, when the zeolite type compound constituting the carrier of the catalyst structure is a silicate compound, the regular mesopore material has pores with a pore diameter of 1 to 50 nm in one, two, or three dimensions. It is preferably a compound consisting of a Si--O skeleton that is uniform in size and regularly developed. Such regular mesoporous materials can be obtained as various synthetic products depending on the synthesis conditions, but specific examples of synthetic products include SBA-1, SBA-15, SBA-16, KIT-6, FSM- No. 16, MCM-41, etc., among which MCM-41 is preferred. The pore diameter of SBA-1 is 10 to 30 nm, the pore diameter of SBA-15 is 6 to 10 nm, the pore diameter of SBA-16 is 6 nm, the pore diameter of KIT-6 is 9 nm, and the pore diameter of FSM-16 is 3. ~5 nm, and the pore size of MCM-41 is 1-10 nm. Examples of such regular mesoporous materials include mesoporous silica, mesoporous aluminosilicate, mesoporous metallosilicate, and the like.

The precursor material (A) may be either a commercially available product or a synthetic product. When synthesizing the precursor material (A), it can be performed by a known method for synthesizing regular mesoporous substances. For example, a mixed solution containing a raw material containing the constituent elements of the precursor material (A) and a templating agent for defining the structure of the precursor material (A) is prepared, and the pH is adjusted as necessary. , perform hydrothermal treatment (hydrothermal synthesis). Thereafter, the precipitate (product) obtained by the hydrothermal treatment is collected (e.g., filtered), washed and dried as necessary, and further calcined to form a powdered regular mesoporous material. A precursor material (A) is obtained. Here, as the solvent for the mixed solution, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. The raw material is selected depending on the type of carrier, and examples include silica agents such as tetraethoxysilane (TEOS), fumed silica, and quartz sand. In addition, various surfactants, block copolymers, etc. can be used as the template agent, and it is preferable to select it depending on the type of composite of the regular mesoporous material. For example, when producing MCM-41, For this purpose, surfactants such as hexadecyltrimethylammonium bromide are suitable. The hydrothermal treatment can be carried out, for example, in a closed container under treatment conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa. The firing treatment can be performed, for example, in air at 350 to 850° C. for 2 to 30 hours.

(Step S2: Impregnation step)
Next, the prepared precursor material (A) is impregnated with a metal-containing solution containing a metal element to obtain a precursor material (B).

The metal-containing solution may be any solution containing a metal component (for example, a metal ion) corresponding to the metal element (M) constituting the functional substance of the catalyst structure. For example, the metal element (M) may be added to the solvent. It can be prepared by dissolving a metal salt containing. Examples of such metal salts include metal salts such as chlorides, hydroxides, oxides, sulfates, and nitrates, of which nitrates are preferred. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used.

The method of impregnating the precursor material (A) with the metal-containing solution is not particularly limited, but for example, before the firing step described below, the precursor material (A) is impregnated with the precursor material (A) while stirring the powdered precursor material (A). ) It is preferable to add the metal-containing solution little by little in multiple portions. In addition, from the viewpoint of making it easier for the metal-containing solution to penetrate into the pores of the precursor material (A), a surfactant may be added as an additive to the precursor material (A) before adding the metal-containing solution. It is preferable to add it in advance. Such additives have the function of coating the outer surface of the precursor material (A), suppressing the adhesion of the metal-containing solution added thereafter to the outer surface of the precursor material (A), and preventing metal-containing solutions from adhering to the outer surface of the precursor material (A). It is thought that the solution contained therein can more easily penetrate into the pores of the precursor material (A).

Examples of such additives include nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, and polyoxyethylene alkylphenyl ether. These surfactants have a large molecular size and cannot penetrate into the pores of the precursor material (A), so they do not adhere to the inside of the pores and prevent the metal-containing solution from entering the pores. It is thought that it will not interfere. As for the method of adding the nonionic surfactant, for example, it is preferable to add 50 to 500% by mass of the nonionic surfactant to the precursor material (A) before the firing step described below. If the amount of the nonionic surfactant added to the precursor material (A) is less than 50% by mass, the above-mentioned suppressing effect will be difficult to exhibit, and the amount of the nonionic surfactant added to the precursor material (A) will be less than 50% by mass. Adding more than % by mass is not preferable because the viscosity increases too much. Therefore, the amount of nonionic surfactant added to the precursor material (A) is set within the above range.

The amount of the metal-containing solution added to the precursor material (A) is determined by the amount of the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) (i.e., the amount of the metal element (M) contained in the metal-containing solution to be impregnated into the precursor material (A)). It is preferable to adjust it appropriately by taking into account the amount of the metal element (M) contained in ). For example, before the firing step described below, the amount of the metal-containing solution to be added to the precursor material (A) is determined based on the metal element (M) contained in the metal-containing solution to be added to the precursor material (A). The ratio of silicon (Si) constituting the precursor material (A) (atomic ratio Si/M) is preferably adjusted to 10 to 1000, and preferably adjusted to 50 to 200. It is more preferable. For example, if a surfactant is added as an additive to the precursor material (A) before adding the metal-containing solution to the precursor material (A), the addition of the metal-containing solution to the precursor material (A) By setting the amount to 50 to 200 in terms of the atomic ratio Si/M, the metal element (M) constituting the functional substance can be contained in an amount of 0.5 to 2.5% by mass relative to the catalyst structure. It can be included. The amount of the metal element (M) present inside the pores in the state of the precursor material (B) is determined under the same conditions as the metal concentration of the metal-containing solution, the presence or absence of the above additives, and other conditions such as temperature and pressure. If present, it is approximately proportional to the amount of metal-containing solution added to the precursor material (A). Further, the amount of the metal element (M) inherent in the precursor material (B) is in a proportional relationship with the amount of the metal element constituting the functional substance inherent in the support of the catalyst structure. Therefore, by controlling the amount of the metal-containing solution added to the precursor material (A) within the above-mentioned range, the metal-containing solution can be sufficiently impregnated into the pores of the precursor material (A). , the amount of the functional substance incorporated into the carrier of the catalyst structure can be adjusted.

After impregnating the precursor material (A) with the metal-containing solution, a cleaning treatment may be performed as necessary. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Further, it is preferable to impregnate the precursor material (A) with a metal-containing solution, perform a cleaning treatment if necessary, and then further perform a drying treatment. Examples of the drying treatment include natural drying for about one night and drying at a high temperature of 150° C. or lower. Note that if the firing treatment described below is performed with a large amount of water contained in the metal-containing solution or water in the cleaning solution remaining in the precursor material (A), the regular mesopores of the precursor material (A) will be removed. Since there is a risk that the skeletal structure of the material may be broken, it is preferable to dry it thoroughly.

(Step S3: Firing process)
Next, the precursor material (B) obtained by impregnating the precursor material (A) with a metal-containing solution to obtain a carrier with a porous structure composed of a zeolite type compound is fired, and the precursor material (C) is obtained. get.

The firing treatment is preferably carried out in air at 350 to 850° C. for 2 to 30 hours, for example. Through such firing treatment, the metal component impregnated into the pores of the regular mesoporous material undergoes crystal growth, and a functional material is formed within the pores.

(Step S4: Hydrothermal treatment step)
Next, a mixed solution of the precursor material (C), a structure directing agent, and an aluminum source is prepared, and the precursor material (C) obtained by firing the precursor material (B) is hydrothermally treated. Obtain a catalyst structure.

The structure directing agent is a template agent for defining the skeletal structure of the skeleton (support) of the catalyst structure, and is composed of organic structure directing agents (usually expressed as "organic structure directing agents" or "OSDA") and OH At least one of the inorganic structure directing agents having ^- can be used. Among these, as the organic structure directing agent, for example, a surfactant can be used. The organic structure directing agent is preferably selected depending on the skeleton structure of the carrier of the catalyst structure, and examples thereof include tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), tetrapropylammonium bromide (TPABr), and tetraethylammonium hydroxy. Surfactants such as TEAOH are suitable. Typical inorganic structure-directing agents are alkali metal and alkaline earth metal hydroxides, such as lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), and hydroxide. Rubidium (Rb(OH)), calcium hydroxide (Ca(OH) ₂ ), strontium hydroxide (Sr(OH) ₂ ), and the like are suitable.

In addition, the aluminum source is a raw material for supplying aluminum contained in the carrier of the catalyst structure, and is dissolved in water to supply Al ions. For example, NaAlO ₂ and Al(OH) ₃ are suitable. be.

The precursor material (C), the structure directing agent, and the aluminum source may be mixed during the main hydrothermal treatment step, or may be mixed before the hydrothermal treatment step. The method for preparing the mixed solution is not particularly limited, and the precursor material (C), the structure directing agent, the aluminum source, and the solvent may be mixed at the same time, or the precursor material (C) may be added to the solvent. ), the structure directing agent, and the aluminum source may be dispersed in individual solutions, and then the respective dispersion solutions may be mixed. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. Moreover, it is preferable to adjust the pH of the mixed solution using an acid or a base before performing the hydrothermal treatment.

The hydrothermal treatment can be carried out by a known method, and is preferably carried out under treatment conditions of 80 to 800° C., 5 hours to 240 hours, and 0 to 2000 kPa in a closed container, for example. Moreover, it is preferable that the hydrothermal treatment is performed in a basic atmosphere. Although the reaction mechanism here is not necessarily clear, by performing hydrothermal treatment using the precursor material (C) as a raw material, the skeletal structure of the precursor material (C) as a regular mesoporous material gradually collapses; While the position of the metal oxide fine particles, which are functional substances, inside the pores of the precursor material (C) is generally maintained, the structure-directing agent allows them to be used as a new skeleton (support) of the catalyst structure. A skeletal structure (porous structure) is formed. At this time, aluminum is incorporated into the new skeleton structure. The catalyst structure thus obtained includes a carrier having a porous structure and fine metal oxide particles contained in the carrier, and furthermore, the carrier has a passageway in which a plurality of pores communicate with each other due to the porous structure. , the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) contained in the carrier 10 is 2.0 or more, and at least a portion of the metal oxide fine particles are retained in the channels of the carrier. . Further, in the present embodiment, in the hydrothermal treatment step, a mixed solution of the precursor material (C), the structure directing agent, and the aluminum source is prepared, and the precursor material (C) is hydrothermally treated. However, the present invention is not limited to this, and only the precursor material (C) and the aluminum source may be mixed and hydrothermally treated without mixing the precursor material (C) and the structure directing agent.

Preferably, the precipitate (catalyst structure) obtained after the hydrothermal treatment is washed, dried, and calcined as necessary after being collected (for example, filtered). As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Examples of the drying treatment include natural drying for about one night and drying at a high temperature of 150° C. or lower. Note that if the calcination treatment is performed with a large amount of moisture remaining in the precipitate, there is a risk that the skeletal structure as a carrier of the catalyst structure may be broken, so it is preferable to dry the precipitate sufficiently. Further, the firing treatment can be performed, for example, in air at 350 to 850° C. for 2 to 30 hours. Through such firing treatment, the structure directing agent attached to the catalyst structure is burned away. Furthermore, depending on the purpose of use, the catalyst structure can be used as it is without performing a calcination treatment on the recovered precipitate. For example, if the environment in which the catalyst structure is used is a high temperature environment with an oxidizing atmosphere, the structure-directing agent will be burned out by exposing it to the use environment for a certain period of time, and the catalyst structure will be the same as in the case of calcination treatment. Therefore, it can be used as is.

The manufacturing method described above is an example in which the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) is a metal species that is difficult to oxidize (for example, Ru, which is a noble metal).

(Step S5: reduction step)
On the other hand, when the metal element (M) contained in the metal-containing solution impregnated into the precursor material (A) contains a metal species that is easily oxidized (for example, Fe, Co, Cu, etc.), the above hydrothermal treatment is performed. After the step, it is preferable to perform a reduction treatment on the hydrothermally treated precursor material (C). If the metal element (M) contained in the metal-containing solution is a metal species that is easily oxidized, the metal component will be oxidized by the heat treatment in the steps (steps S3 to S4) after the impregnation treatment (step S2). . Therefore, the carrier formed in the hydrothermal treatment step (step S4) contains metal oxide fine particles as a functional substance. Therefore, in order to obtain a catalyst structure in which a functional substance is contained in the carrier, after the above-mentioned hydrothermal treatment, the recovered precipitate is calcined as necessary, and then reduced in an atmosphere of a reducing gas such as hydrogen gas. This is desirable. By performing the reduction treatment, the metal oxide fine particles contained in the carrier are reduced, and a functional substance made of metal fine particles corresponding to the metal element (M) constituting the metal oxide fine particles is formed. As a result, a catalyst structure is obtained in which fine metal particles are included as a functional substance in the carrier. At this time, by adjusting the degree of reduction in the reduction step, it is possible to suppress or adjust the functional deterioration of the catalyst structure in which the metal or metal oxide is contained. Note that such a reduction treatment may be carried out as necessary. For example, if the environment in which the catalyst structure is used can become a reducing atmosphere at least temporarily, the reduction treatment may be performed for a certain period of time in an environment containing a reducing atmosphere. Since the metal oxide fine particles are reduced by exposure, a catalyst structure similar to that obtained by reduction treatment can be obtained, so that it can be used as is with the oxide fine particles contained in the carrier.

[Modified example of FT synthesis catalyst structure]
FIG. 4 is a schematic diagram showing a modification of the catalyst structure 1 shown in FIG. Although the catalyst structure 1 in FIG. 1 is shown as comprising a carrier 10 and a functional substance 20 inherent in the carrier 10, the structure is not limited to this structure, and for example, as shown in FIG. The catalyst structure 2 may further include other functional substances 30 held on the outer surface 10a of the carrier 10.

This functional material 30 is a catalytic material that exhibits one or more catalytic abilities at least when used as a catalyst. The catalytic ability of the other functional substance 30 may be the same as or different from the catalytic ability of the functional substance 20. Further, when both the functional substances 20 and 30 are catalytic substances having the same catalytic ability, the material of the other functional substance 30 may be the same as the material of the functional substance 20 or may be different. It's okay. According to this configuration, the content of the functional substance held in the catalyst structure 2 can be increased, and the catalytic activity of the functional substance can be further promoted.

In this case, the content of the functional substance 20 inherent in the carrier 10 is preferably greater than the content of other functional substances 30 held on the outer surface 10a of the carrier 10. As a result, the catalytic ability of the functional substance 20 held inside the carrier 10 becomes dominant, and the catalytic ability of the functional substance is stably exhibited.

[Hydrocarbon production method, hydrocarbon production equipment]
The present invention also provides a method for producing hydrocarbons, which synthesizes hydrocarbons from carbon monoxide and hydrogen using a catalyst. Such a catalyst includes a carrier 10 having a porous structure made of a zeolite type compound, and at least one functional substance 20 inherent in the carrier 10, and the carrier 10 has passages 11 that communicate with each other. However, the value of the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) contained in the carrier 10 is 2.0 or more, and the functional substance 20 expands at least the passages 11 of the carrier 10. It includes the FT synthesis catalyst structure 1 present in the diameter section 12. That is, the present invention provides a method for producing hydrocarbons in which hydrocarbons are synthesized from carbon monoxide and hydrogen using the above-described FT synthesis catalyst structure. Furthermore, by producing hydrocarbons using the FT synthesis catalyst structure 1, the formation or adhesion of coke on the surface of the FT synthesis catalyst structure 1 is suppressed, and thereby the FT synthesis catalyst structure 1 after the reaction is The amount of coke can be reduced.

There are no particular restrictions on the raw materials used when carrying out the method for producing hydrocarbons using Fischer-Tropsch synthesis reactions, as long as the main components are molecular hydrogen and carbon monoxide, but hydrogen/ Synthesis gas with a carbon monoxide molar ratio of 1.5 to 2.5 is preferred, and synthesis gas with a molar ratio of 1.8 to 2.2 is more preferred. Furthermore, the reaction conditions for the FT synthesis reaction are not particularly limited, and the reaction can be carried out under known conditions. For example, the reaction temperature is preferably 200 to 500°C, and the pressure is preferably 0.1 to 3.0 MPa (absolute pressure).

The Fischer-Tropsch synthesis reaction can be carried out in a process known as a Fischer-Tropsch synthesis reaction process, such as a fixed bed, a supercritical fixed bed, a slurry bed, a fluidized bed, and the like. Preferred processes include fixed bed, supercritical fixed bed, and slurry bed.

Moreover, in the present invention, a hydrocarbon production apparatus having the above catalyst structure may be provided. Such hydrocarbon production equipment is not particularly limited as long as it can perform Fischer-Tropsch synthesis using the catalyst structure as a catalyst, and includes, for example, an FT synthesis reaction apparatus, an FT synthesis reaction column, etc. Commonly used manufacturing equipment can be used. By using the catalyst structure according to the present invention in such a hydrocarbon production apparatus, the production apparatus can also achieve the same effects as described above.

The catalyst structure, the method for manufacturing the same, the method for producing hydrocarbons using the catalyst structure, and the hydrocarbon production apparatus having the catalyst structure according to the embodiments of the present invention have been described above. The present invention is not limited to the embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

(Examples 1 to 40)
[Synthesis of precursor material (A)]
A mixed aqueous solution of a silica agent (tetraethoxysilane (TEOS), manufactured by Wako Pure Chemical Industries, Ltd.) and a surfactant as a template agent was prepared, the pH was adjusted as appropriate, and the solution was heated to 80 to Hydrothermal treatment was performed at 350°C for 100 hours. Thereafter, the generated precipitate is filtered, washed with water and ethanol, and further calcined in air at 600°C for 24 hours to obtain a powdered precursor having the type and pore size shown in Tables 1 and 3. Material (A) was obtained. The following surfactants were used depending on the type of precursor material (A) ("Type of precursor material (A): surfactant").
・MCM-41: Hexadecyltrimethylammonium bromide (CTAB) (manufactured by Wako Pure Chemical Industries, Ltd.)

[Preparation of precursor materials (B) and (C)]
Next, depending on the metal element (M) constituting the type of functional substance (catalyst substance) shown in Tables 2 and 4, a metal salt containing the metal element (M) is dissolved in water. , a metal-containing aqueous solution was prepared. Note that the following metal salts were used depending on the type of metal fine particles that were functional substances ("metal fine particles: metal salt").
・Co: Cobalt(II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・Ni: Nickel (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・Fe: Iron (III) nitrate nonahydrate (manufactured by Wako Pure Chemical Industries, Ltd.)
・Ru: Ruthenium (III) chloride anhydrous (manufactured by Tokyo Chemical Industry Co., Ltd.)

This precursor material (A) is pretreated by adding an aqueous solution of polyoxyethylene (15) oleyl ether (NIKKOL BO-15V, manufactured by Nikko Chemicals Co., Ltd.) as an additive. A metal-containing aqueous solution was added in small portions to (A) in multiple portions and dried at room temperature (20° C.±10° C.) for 12 hours or more to obtain precursor material (B).

The amount of the metal-containing aqueous solution added to the precursor material (A) is determined by the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing aqueous solution ( The values were adjusted so that the values when converted to the atomic ratio (Si/M) were as shown in Tables 1 and 3.

Next, the precursor material (B) impregnated with the metal-containing aqueous solution obtained as described above was fired in air at 600° C. for 24 hours to obtain a precursor material (C).

The precursor material (C) obtained as above, aluminum hydroxide (Al(OH) ₃ , manufactured by Sigma Aldrich) as an aluminum source, and the structure directing agent shown in Tables 1 and 3 were mixed. A mixed aqueous solution was prepared, and hydrothermal treatment was performed in a closed container under the conditions of 80 to 350°C, pH and time shown in Tables 1 and 3. Thereafter, the generated precipitate was filtered, washed with water, dried at 100°C for 12 hours or more, and further calcined in air at 600°C for 24 hours. Thereafter, the calcined product was collected and subjected to reduction treatment at 500°C for 60 minutes under the inflow of hydrogen gas to obtain a catalyst structure having the carrier shown in Tables 1 and 3 and metal fine particles as a catalyst material. (Examples 1-40).

(Comparative Examples 1 to 3)
Comparative Examples 1 to 3 were carried out in the same manner as in Examples 1, 5, and 8, respectively, except that the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) was set to 1.8. A catalyst structure was obtained.

(Comparative example 4)
In Comparative Example 4, cobalt oxide powder (II, III) (manufactured by Sigma-Aldrich Japan LLC) with an average particle size of 50 nm or less was mixed with MFI type silicalite, and hydrogen reduction treatment was performed in the same manner as in the example. A catalyst structure was obtained in which cobalt fine particles were attached as a catalyst substance to the outer surface of silicalite as a carrier. MFI type silicalite was synthesized in the same manner as in Example 1 except for the step of adding metal.

(Comparative example 5)
In Comparative Example 5, MFI type silicalite was synthesized in the same manner as Comparative Example 4, except that the step of attaching cobalt fine particles was omitted.

[evaluation]
Various characteristic evaluations were performed on the catalyst structure of the above example and the silicalite of the comparative example under the conditions shown below.

[A] Cross-sectional observation For the catalyst structure of the above example and the silicalite of the comparative example, observation samples were prepared by a pulverization method, and cross-sectional observation was performed using a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI). I did it. As a result, it was confirmed that in the catalyst structure of the above example, fine metal particles of cobalt, iron, nickel, or ruthenium were contained and retained as a catalyst substance inside the carrier made of silicalite or zeolite. On the other hand, in the silicalite of Comparative Example 4, cobalt metal fine particles were only attached to the outer surface of the carrier and were not present inside the carrier.

In addition, for the catalyst structure in which the metal is iron (Fe) fine particles among the above examples, a cross section was cut out by FIB (focused ion beam) processing, and SEM (SU8020, manufactured by Hitachi High-Technologies), EDX (X-Max , manufactured by Horiba, Ltd.) for cross-sectional elemental analysis. As a result, Fe element was detected inside the carrier. From the results of cross-sectional observation using the above TEM and SEM/EDX, it was confirmed that Fe fine particles were present inside the carrier.

[B] Average inner diameter of carrier passages and average particle diameter of metal fine particles 500 carrier passages were arbitrarily selected from the TEM images taken by the cross-sectional observation performed in the above evaluation [A], and the major diameter and The short axis was measured, and the inner diameter of each was calculated from the average value (N=500), and the average value of the inner diameter was determined to be the average inner diameter _DF of the carrier passage.

Further, in order to confirm the average particle size and dispersion state of the metal fine particles, analysis was performed using SAXS (small angle X-ray scattering). Measurements by SAXS were performed using Spring-8 beamline BL19B2. The obtained SAXS data was fitted with a spherical model using the Guinier approximation method, and the average particle size of the catalyst material was calculated. Regarding the particle size, the average particle size of Fe fine particles was measured for a catalyst structure having Fe fine particles as a catalyst material. In addition, as a comparison object, commercially available Fe fine particles (manufactured by Wako) were observed and measured using a SEM. The results are shown in Tables 2 and 4.

As a result, whereas in commercially available products, iron fine particles of various sizes exist randomly in the particle size range of about 50 nm to 400 nm, each product having metal fine particles with an average particle size of 1.5 nm to 1.6 nm was found. In the catalyst structure of the example, as a result of SAXS measurement, scattering peaks corresponding to the particle size values of each example listed in Tables 2 and 4 were detected within the particle size range of 10 nm or less. From the SAXS measurement results and the SEM/EDX cross-sectional measurement results, metal fine particles (Fe fine particles) that serve as a catalyst substance with a particle size of 10 nm or less exist inside the carrier in a highly dispersed state with uniform particle sizes. I found out that there is.

[C] Relationship between the amount of the metal element (M) added to the precursor material (A) and the content of the metal element (M) included as a functional substance inside the carrier constituting the catalyst structure Precursor When the material (A) is impregnated with a metal-containing solution, the amount of the metal element (M) added in the precursor material (A) is such that the atomic ratio Si/M = 100, and the metal fine particles function. A catalyst structure was prepared in which a catalytic substance was included inside a carrier. Thereafter, the amount of metal (mass %) included inside the carrier of each catalyst structure produced with the above addition amount was measured.

The amount of metal was determined by ICP (inductively coupled plasma) alone or by a combination of ICP and XRF (X-ray fluorescence analysis). XRF (energy dispersive X-ray fluorescence spectrometer "SEA1200VX", manufactured by SSI Nanotechnology) was carried out under the conditions of a vacuum atmosphere and an accelerating voltage of 15 kV (using a Cr filter) or 50 kV (using a Pb filter). XRF is a method for calculating the amount of metal present based on fluorescence intensity, and a quantitative value (in terms of mass %) cannot be calculated using XRF alone. Therefore, the contents of the metal element (M) and Si atoms in the catalyst structure to which metal was added with Si/M=100 were determined by ICP analysis.

[D] Value of atomic ratio (Si/Al ratio) in carrier The amounts of aluminum (Al) and silicon (Si) contained in the carrier were determined using ICP (inductively coupled plasma). Then, the atomic ratio (Si/Al ratio) was determined from the measured amounts of aluminum (Al) and silicon (Si).

[E] Performance Evaluation The catalytic ability of the metal fine particles was evaluated for the catalyst structure of the above example and the silicalite of the comparative example. The results are shown in Tables 2 and 4.

(1) Evaluation of catalytic activity Catalytic activity was evaluated under the following conditions.
First, 70 mg of the catalyst structure was packed into an atmospheric pressure flow reactor, hydrogen (8 ml/min) and carbon monoxide (4 ml/min) were supplied, and the pressure inside the equipment was adjusted to 0.1 MPa. Fischer-Tropsch synthesis was performed by increasing the temperature at 20°C/min in the temperature range of 100 to 700°C and then holding the temperature for 1 hour. Here, a single microreactor (Rx-3050SR, Frontier Lab) was used as the atmospheric pressure flow reactor.

After the reaction was completed, the components of the recovered product gas and solution were analyzed by gas chromatography mass spectrometry (GC/MS). Here, TRACE 1310GC (manufactured by Thermo Fisher Scientific Co., Ltd., detector: thermal conductivity detector) was used as an analyzer for the produced gas and produced liquid.

Furthermore, based on the results of the above component analysis, the products obtained by the FT synthesis reaction were confirmed. In this evaluation, the above operations were performed at 250°C, 350°C, and 400°C using the catalyst structures obtained in Examples and Comparative Examples, respectively, and the results were evaluated based on the following evaluation criteria.

Here, if the production of hydrocarbons (excluding CH ₄ , the same applies hereinafter) is confirmed at 250°C (in other words, when the reaction initiation temperature is 250°C or lower), it is assumed that the catalyst activity in the FT synthesis reaction is excellent. If the result is ``○'', and the generation of hydrocarbons is confirmed at 350°C (in other words, the reaction initiation temperature is higher than 250°C and 350°C or lower), the catalytic activity is not good, but it is judged to be a passing level (acceptable). ) and ``△'', if hydrocarbon generation was confirmed at 400°C (in other words, the reaction initiation temperature was higher than 350°C and below 400°C), or if the FT synthesis reaction did not occur. It was determined that the catalyst activity was poor (impossible) and was rated "×".

(2) Evaluation of coke generation/adhesion suppression ability 70 mg of the obtained catalyst structure was packed into an atmospheric pressure flow reactor, hydrogen (8 ml/min) and carbon monoxide (4 ml/min) were supplied, Fischer Tropsch synthesis reaction was performed. Here, a single microreactor (manufactured by Frontier Lab, product name: Rx-3050SR) was used as the atmospheric pressure flow reactor.

After the Fischer-Tropsch synthesis reaction was completed, the catalyst used in the test was collected and the amount of carbon on the catalyst was analyzed using CHN (equipment name: CHN analyzer (CE440, Exeter Analytical, Inc.). This result regarding the coke amount in the FT synthesis reaction is considered as the result of "coke generation/adhesion inhibiting property", and the case where the C amount (coke amount) is less than the detection limit (0.3 mass%) is considered to be the result of coke generation or adhesion in the FT synthesis reaction. If it is 0.3% by mass or more and less than 0.5% by mass, it is determined to be excellent in suppressing coke formation or adhesion, and "○" is determined. If it is .5% by mass or more and less than 1.0% by mass, it is judged as a passing level (acceptable) although the suppression of coke generation or adhesion is not good, and it is marked "△", and if it is 1.0% by mass or more, it is judged as "fair". It was determined that the suppression of coke formation or adhesion was inferior (unable) and was rated "×".

Comparative Examples 1 to 5 were also evaluated for performance in the same manner. Note that Comparative Example 5 is a carrier itself and does not contain any functional substance. Therefore, in the above performance evaluation, only the carrier of Comparative Example 5 was filled instead of the catalyst structure. The results are shown in Tables 2 and 4.

As is clear from Tables 1 to 4, the catalyst structures (Examples 1 to 40) in which it was confirmed by cross-sectional observation that metal fine particles, which are functional substances, were retained inside the carrier were used in the FT synthesis reaction. It was found that it exhibited excellent catalytic activity and that the amount of coke adhering to the catalyst structure after the FT synthesis reaction was also small.

Further, regarding the catalyst structure obtained in the above evaluation [C], the relationship between the amount of metal (mass %) included inside the carrier and the catalytic activity of the above evaluation (1) was evaluated. The evaluation method was the same as the evaluation method performed in "(1) Catalyst activity" in the above [E] "Performance evaluation". As a result, in each example, the amount of the metal-containing solution added to the precursor material (A) was 100 in terms of the atomic ratio Si/M (the content of the metal element (M) with respect to the catalyst structure was 0.52 to 1.09% by mass), the catalyst activity is improved in the FT synthesis reaction, and the amount of coke adhering to the catalyst structure after the FT synthesis reaction tends to be small.

Furthermore, regarding the catalyst structure of the present invention, the relationship between the amount of metal (mass %) included inside the carrier and the catalytic activity of the above evaluation (1) was evaluated. The evaluation method was the same as the evaluation method performed in "(1) Catalyst activity" in the above [D] "Performance evaluation". As a result, when the amount of the metal-containing solution added to the precursor material (A) is 10 to 1000 in terms of the atomic ratio Si/M, it is more preferably 50 to 200 (metal element relative to the catalyst structure). It was found that when the content of M) is 0.5 to 2.5% by mass), the catalytic activity tends to improve in the FT synthesis reaction.

Furthermore, when comparing the catalytic activity of a catalyst structure in which fine metal particles containing Co are included and a catalyst structure in which fine metal particles containing Fe, Ni or Ru are included, it is found that No matter when Ru is included as metal fine particles, when the Si/Al ratio is 25 or more, the evaluation result regarding coke generation/adhesion suppression is "◎", and especially when Co is included as metal fine particles, the evaluation result is "◎". In the case of inclusion, even if the Si/Al ratio was 8.6 or more and less than 25, the evaluation result regarding the ability to inhibit coke formation and adhesion was "◎". On the other hand, when Fe, Ni, or Ru is included as fine metal particles, the evaluation result may be "○" when the Si/Al ratio is 2 or more and less than 25. In addition, as representative examples, Example 1 (Co inclusion catalyst structure) and Examples 10, 17, and 30 (Fe, The GC/MS areas of hydrocarbons (C ₂ to C ₂₀ ) of Ni, Ru inclusion catalyst structures were compared. As a result, the Co inclusion catalyst structure had a peak area approximately 1.4 times that of the Fe, Ni, and Ru inclusion catalyst structure. From these results, it was found that Co is more suitable as the clathrate metal species than Fe, Ni, or Ru.

On the other hand, in the catalyst structures of Comparative Examples 1 to 3 with a small Si/Al ratio of 1.8, the zeolite-type compound did not crystallize, and the evaluation results regarding coke generation and adhesion suppression were all "x". there were. In addition, the catalyst structure of Comparative Example 4, in which metal fine particles were attached only to the outer surface of the support, had improved catalytic activity in the FT synthesis reaction compared to the support itself of Comparative Example 5, which did not have any metal fine particles. However, compared to the catalyst structures of Examples 1 to 40, the amount of coke was larger.

From the above results, the catalyst structures (Examples 1 to 40) showed excellent catalytic activity in the FT synthesis reaction, which synthesizes hydrocarbons from carbon monoxide and hydrogen, and also exhibited excellent catalytic activity when used in the Fischer-Tropsch synthesis reaction. It can be inferred that the amount of coke can be reduced.

[Other embodiments]
A method using a Fischer-Tropsch synthesis catalyst structure, the method comprising:
The catalyst structure is a carrier having a porous structure composed of a zeolite type compound;
at least one functional substance inherent in the carrier,
The carrier contains aluminum (Al) and silicon (Si),
The ratio of silicon (Si) to aluminum (Al) (atomic ratio Si/Al) contained in the carrier is 2.0 or more,
the carrier has passages that communicate with each other,
A method of using a Fischer-Tropsch synthesis catalyst structure, characterized in that the functional substance has characteristics that prevent coke formation or adhesion, and is present in at least the passageway of the carrier.

1 FT synthesis catalyst structure 10 carrier 10a outer surface 11 passage 11a pore 12 enlarged diameter portion 20 functional substance 30 functional substance D _C average particle diameter D _F average inner diameter D _E inner diameter

Claims (20)

A carrier made of a zeolite-type compound with a porous structure in which at least one type of pores among one-dimensional pores, two-dimensional pores, and three-dimensional pores are formed;
at least one functional substance inherent in the carrier and having catalytic activity as a Fischer-Tropsch synthesis catalyst;
A Fischer-Tropsch synthesis catalyst structure comprising:
The carrier contains aluminum (Al) and silicon (Si),
The ratio of silicon (Si) to aluminum (Al) (atomic ratio Si/Al) contained in the carrier is 2.0 or more,
the carrier has passages that communicate with each other,
The functional substance is metal fine particles containing one or more metals or alloys selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni) and ruthenium (Ru), or cobalt, iron and Metal oxide fine particles containing one or more metal elements selected from the group consisting of nickel, and present at least in an enlarged diameter portion of the carrier that is different from the at least one pore,
The ratio of the average particle size of the functional substance to the average inner diameter of the passage is 1.1 to 300,
A Fischer-Tropsch synthesis catalyst structure, wherein the average inner diameter of the passage is calculated from the average value of the minor axis and major axis of the pores constituting the at least one type of pores. The catalyst structure was prepared by filling an atmospheric pressure flow reactor with 70 mg of the catalyst structure, and supplying hydrogen at a flow rate of 8 ml/min and carbon monoxide at a flow rate of 4 ml/min. The Fischer-Tropsch synthesis catalyst structure according to claim 1, wherein the amount of coke after performing the Fischer-Tropsch synthesis reaction for 1 hour at a reaction temperature of 700° C. with a pressure adjusted to 0.1 MPa is less than 1% by mass. body. The Fischer-Tropsch synthesis according to claim 1 or 2, wherein the expanded diameter portion communicates with each other a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Catalyst structure. The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 3, wherein the average particle diameter of the functional substance is equal to or less than the inner diameter of the enlarged diameter portion. Any one of claims 1 to 4, wherein the metal element (M) of the functional substance is contained in an amount of 0.5 to 2.5% by mass based on the Fischer-Tropsch synthesis catalyst structure. The Fischer-Tropsch synthesis catalyst structure according to item 1. The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 5, wherein the functional substance has an average particle size of 0.4 nm to 11.0 nm. The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 6, characterized in that the ratio of the average particle size of the functional substance to the average inner diameter of the passage is 1.1 to 30. body. The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 7, characterized in that the average inner diameter of the passages is 0.1 nm to 1.5 nm. The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 8, wherein the inner diameter of the expanded diameter portion is 0.5 nm to 50 nm. Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 9, characterized in that the at least one functional substance is further retained on the outer surface of the support. Claim 10, characterized in that the content of the at least one functional substance inherent in the carrier is greater than the content of the at least one functional substance retained on the outer surface of the carrier. Fischer-Tropsch synthesis catalyst structure described in . The Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 11, wherein the zeolite type compound is a silicate compound. A hydrocarbon production apparatus comprising the Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 12. Cobalt (Co), iron (Fe), nickel (Ni) and ruthenium (Ru ) The precursor material (B) impregnated with a metal-containing solution containing a salt of one or more metal components selected from the group consisting of: a firing step of obtaining a precursor material (C) in which a functional substance is formed from the metal component of the containing solution;
a hydrothermal treatment step of hydrothermally treating the precursor material (C) to obtain a Fischer-Tropsch synthesis catalyst structure;
A method for producing a Fischer-Tropsch synthesis catalyst structure, comprising:
The hydrothermal treatment step is performed using a mixed solvent in which the precursor material (C), an aluminum source, and a structure directing agent are mixed in a solvent,
The carrier contains aluminum (Al) and silicon (Si),
A method for producing a Fischer-Tropsch synthesis catalyst structure, characterized in that the atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) contained in the support is 2.0 or more. The Fischer-Tropsch synthesis catalyst structure according to claim 14, characterized in that, before the calcination step, 50 to 500% by mass of a nonionic surfactant is added to the precursor material (A). How the body is manufactured. Before the firing step, the metal-containing solution is added to the precursor material (A) in multiple portions to impregnate the precursor material (A) with the metal-containing solution. A method for producing a Fischer-Tropsch synthesis catalyst structure according to claim 14 or 15. When impregnating the precursor material (A) with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is determined by adjusting the amount of the metal-containing solution added to the precursor material (A). The atomic ratio (Si/M ratio) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to the solution is 10 to 1000. The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of claims 14 to 16, characterized in that the structure is adjusted to: The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of claims 14 to 17, wherein the hydrothermal treatment step is performed in a basic atmosphere. The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of claims 14 to 18, further comprising a step of reducing the functional substance after the hydrothermal treatment step. A method for producing hydrocarbons in which hydrocarbons are synthesized from carbon monoxide and hydrogen using a catalyst, the catalyst comprising:
A carrier made of a zeolite-type compound with a porous structure in which at least one type of pores among one-dimensional pores, two-dimensional pores, and three-dimensional pores are formed;
A Fischer-Tropsch synthesis catalyst structure comprising at least one functional substance inherent in the carrier and having catalytic activity as a Fischer-Tropsch synthesis catalyst,
The carrier contains aluminum (Al) and silicon (Si),
The atomic ratio of silicon (Si) to aluminum (Al) (Si/Al ratio) contained in the support is 2.0 or more,
the carrier has passages that communicate with each other,
The functional substance is metal fine particles containing one or more metals or alloys selected from the group consisting of cobalt (Co), iron (Fe), nickel (Ni) and ruthenium (Ru), or cobalt, iron and Metal oxide fine particles containing one or more metal elements selected from the group consisting of nickel, and present at least in an enlarged diameter portion of the carrier that is different from the at least one pore,
The ratio of the average particle size of the functional substance to the average inner diameter of the passage is 1.1 to 300,
A method for producing hydrocarbons, wherein the average inner diameter of the passage is calculated from the average value of the short axis and long axis of the holes constituting the at least one type of hole.

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