阅读说明：本技术 费托合成催化剂结构体、其制造方法、使用了该催化剂结构体的液态烃的制造方法及具有该催化剂结构体的烃制造装置 (Fischer-Tropsch synthesis catalyst structure, method for producing same, method for producing liquid hydrocarbon using same, and hydrocarbon production device provided with same ) 是由 增田隆夫 中坂佑太 吉川琢也 加藤祯宏 福岛将行 高桥寻子 马场祐一郎 关根可织 于 2018-05-31 设计创作，主要内容包括：提供一种费托合成催化剂结构体、其制造方法、使用了该催化剂结构体的液态烃的制造方法及具有该催化剂结构体的烃制造装置,所述费托合成催化剂结构体能够防止金属微粒彼此的凝聚并且抑制催化活性的降低而实现长寿命化,不需要繁杂的更换作业并且能够谋求节约资源。费托合成催化剂结构体(1)具备：多孔质结构的载体(10),其由沸石型化合物构成；以及至少一种金属微粒(20),其存在于所述载体(10)内,所述载体(10)具有相互连通的通道(11),所述金属微粒(20)存在于所述载体(10)的至少通道(11)。(Provided are a Fischer-Tropsch synthesis catalyst structure which can prevent the aggregation of metal fine particles, suppress the decrease in catalytic activity, increase the lifetime, eliminate the need for complicated replacement work, and save resources, a method for producing the same, a method for producing liquid hydrocarbons using the catalyst structure, and a hydrocarbon production apparatus having the catalyst structure. A Fischer-Tropsch synthesis catalyst structure (1) is provided with: a porous support (10) composed of a zeolite-type compound; and at least one metal particle (20) present in the carrier (10), the carrier (10) having interconnected channels (11), the metal particle (20) being present in at least the channels (11) of the carrier (10).)

1. A Fischer-Tropsch synthesis catalyst structure comprising:

a porous support composed of a zeolite-type compound; and

at least one metal particulate present within the carrier,

the carrier has channels that are in communication with each other,

the metal particles are present in at least the channels of the carrier.

2. A Fischer-Tropsch synthesis catalyst structure according to claim 1,

the channel has: any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound; and a diameter expanding portion that is different from any of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole, and that expands the diameter of the hole

The metal fine particles are present at least in the diameter-expanded portion.

3. The Fischer-Tropsch synthesis catalyst structure of claim 2,

the diameter expanding portion causes a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole to communicate with each other.

4. A Fischer-Tropsch synthesis catalyst structure according to claim 2 or 3,

the metal fine particles have an average particle diameter larger than an average inner diameter of the channel and equal to or smaller than an inner diameter of the enlarged diameter portion.

5. Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 4,

the metal element (M) of the fine metal particles is contained in an amount of 0.5 to 2.5 mass% based on the Fischer-Tropsch synthesis catalyst structure.

6. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 5,

the metal fine particles include Co, Fe, Ni, or an alloy containing at least one of them.

7. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 6,

the metal fine particles have an average particle diameter of 0.08 to 30 nm.

8. A Fischer-Tropsch synthesis catalyst structure according to claim 7,

the metal fine particles have an average particle diameter of 0.4 to 11.0 nm.

9. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 8,

the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the channel is 0.05 to 300.

10. A Fischer-Tropsch synthesis catalyst structure according to claim 9,

the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the channel is 0.1 to 30.

11. A Fischer-Tropsch synthesis catalyst structure according to claim 10,

the ratio of the average particle diameter of the metal fine particles to the average inner diameter of the channel is 1.4 to 3.6.

12. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 11,

the channel has: any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound; and a diameter expanding portion different from any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole,

the average inner diameter of the channel is 0.1 nm-1.5 nm,

the inner diameter of the diameter-expanded portion is 0.5nm to 50 nm.

13. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 12,

at least one other metal particulate is also provided, which is retained on the outer surface of the carrier.

14. A Fischer-Tropsch synthesis catalyst structure according to claim 13,

the at least one metal particulate is present in the carrier in an amount greater than the amount of the at least one other metal particulate retained on the outer surface of the carrier.

15. A Fischer-Tropsch synthesis catalyst structure according to any one of claims 1 to 14,

the zeolite-type compound is a silicate compound.

16. A hydrocarbon production apparatus having the fischer-tropsch synthesis catalyst structure of any one of claims 1 to 15.

17. A method for producing a Fischer-Tropsch synthesis catalyst structure, comprising:

a firing step of firing a precursor material (B) obtained by impregnating a precursor material (a) with a metal-containing solution, the precursor material (a) being used for obtaining a support having a porous structure made of a zeolite-type compound;

a hydrothermal treatment step of subjecting a precursor material (C) obtained by firing the precursor material (B) to hydrothermal treatment; and

and a step of subjecting the precursor material (C) after the hydrothermal treatment to a reduction treatment.

18. The method for producing a Fischer-Tropsch synthesis catalyst structure according to claim 17,

before the firing step, 50 to 500 mass% of a nonionic surfactant is added to the precursor material (a).

19. The method of producing a Fischer-Tropsch synthesis catalyst structure according to claim 17 or 18,

the metal-containing solution is impregnated into the precursor material (a) by adding the metal-containing solution to the precursor material (a) a plurality of times before the firing step.

20. A method of manufacturing a Fischer-Tropsch synthesis catalyst structure according to any one of claims 17 to 19,

when the precursor material (A) is immersed in the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is adjusted so that the atomic ratio Si/M, which is the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to the precursor material (A), is 10 to 1000.

21. The method for producing a Fischer-Tropsch synthesis catalyst structure according to claim 17,

in the hydrothermal treatment step, the precursor material (C) is mixed with a structure-directing agent.

22. The method for producing a Fischer-Tropsch synthesis catalyst structure according to claim 17,

the hydrothermal treatment step is performed in an alkaline environment.

23. A process for producing liquid hydrocarbons, which comprises synthesizing liquid hydrocarbons from carbon monoxide and hydrogen using a catalyst,

the catalyst contains a Fischer-Tropsch synthesis catalyst structure, and the Fischer-Tropsch synthesis catalyst structure comprises:

a porous support composed of a zeolite-type compound; and

at least one metal particulate present within the carrier,

the carrier has channels that are in communication with each other,

the metal microparticles are present in at least the expanded diameter portion of the channel of the carrier.

Technical Field

The present invention relates to a fischer-tropsch synthesis catalyst structure, a method for producing the same, a method for producing liquid hydrocarbons using the catalyst structure, and a hydrocarbon production apparatus having the catalyst structure.

Background

As a method for producing hydrocarbon compounds used as a raw material for liquid fuel products such as synthetic oil and synthetic fuel which are alternative fuels to petroleum, a method for producing hydrocarbon compounds is knownBy catalytic reaction of carbon monoxide gas (CO) and hydrogen gas (H)₂) A fischer-tropsch synthesis reaction (hereinafter, also referred to as "FT synthesis reaction") in which a synthesis gas as a main component synthesizes hydrocarbons, particularly liquid hydrocarbons. As a catalyst used in this FT synthesis reaction, for example, patent document 1 discloses a catalyst in which an active metal such as cobalt or iron is supported on a carrier such as silica or alumina, and patent document 2 discloses a catalyst containing cobalt, zirconium or titanium and silica.

The catalyst used in the FT synthesis reaction can be obtained by impregnating a carrier such as silica or alumina with a cobalt salt or ruthenium salt, and calcining the impregnated carrier (unreduced catalyst) to support a cobalt oxide and/or ruthenium oxide. In order to allow the catalyst obtained in this way to exhibit sufficient activity in the FT synthesis reaction, it is necessary to bring the catalyst into contact with a reducing gas such as hydrogen gas to perform a reduction treatment, as disclosed in patent document 3, to convert cobalt and/or ruthenium, which are active metals, from an oxide state to a metal state.

Further, it is known that, since the FT synthesis reaction involves extreme heat generation as disclosed in patent document 4, local overheating occurs on the catalyst surface, and thus the activity is deteriorated by the progress of side reactions (deposition of carbonaceous matter, etc.) at the overheated portions generated on the catalyst surface. In order to prevent the formation of such hot spots, it is necessary to disperse the active sites without aggregating the active metal species (metal fine particles) that function as a catalyst. In order to prevent the aggregation of the active metal species, it is considered that the metal fine particles are not easily aggregated with each other by using a carrier having a strong interaction with the active metal species.

As an example of this method, a sol-gel method is known in which metal fine particles are supported with high dispersion. In the sol-gel method, active metal species are uniformly introduced at an atomic level at the stage of synthesizing a metal oxide as a support. Since the active metal species of the supported metal catalyst is contained in the crystal lattice of the metal oxide as the carrier in an extremely highly dispersed state, the active metal species are not easily aggregated in various treatments and reactions. However, since the active metal species is strongly bonded to the carrier, there is a problem that activation of the catalyst before the reaction becomes difficult, and sufficient catalytic activity cannot be obtained.

Further, when the metal fine particles are aggregated with each other, the catalyst activity is lowered with a decrease in the effective surface area as a catalyst, and therefore, the life of the catalyst itself is shorter than usual. Therefore, the catalyst itself must be replaced and regenerated in a short period of time, which causes a problem that the replacement operation is complicated and the resource saving cannot be achieved.

Disclosure of Invention

Problems to be solved by the invention

An object of the present invention is to provide a fischer-tropsch synthesis catalyst structure that can prevent aggregation of fine metal particles, suppress a decrease in catalytic activity, and achieve a long life, that does not require a complicated replacement operation, and that can achieve resource saving, a method for producing the same, a method for producing liquid hydrocarbons using the catalyst structure, and a hydrocarbon production apparatus having the catalyst structure.

Technical scheme

As a result of intensive studies to achieve the above object, the present inventors have found that a fischer-tropsch synthesis catalyst structure comprising: a porous support composed of a zeolite-type compound; and at least one metal fine particle present in the carrier, the carrier having mutually communicating channels, and the metal fine particle being present in at least the channels of the carrier, whereby a catalyst structure capable of preventing the metal fine particles from aggregating with each other and suppressing a decrease in catalytic activity to achieve a long life can be obtained.

That is, the gist of the present invention is as follows.

[1] A Fischer-Tropsch synthesis catalyst structure comprising:

a porous support composed of a zeolite-type compound; and

at least one metal particulate present within the carrier,

the carrier has channels that are in communication with each other,

the metal particles are present in at least the channels of the carrier.

[2] A Fischer-Tropsch synthesis catalyst structure body according to the above [1], characterized in that the channels have: any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound; and an expanded diameter portion that is different from any of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole, and in which the metal fine particles are present at least in the expanded diameter portion.

[3] The Fischer-Tropsch synthesis catalyst structure according to item [2], wherein the diameter-enlarged portion causes a plurality of pores constituting any one of the one-dimensional pores, the two-dimensional pores, and the three-dimensional pores to communicate with each other.

[4] A Fischer-Tropsch synthesis catalyst structure according to the above [2] or [3], characterized in that the average particle diameter of the fine metal particles is larger than the average inner diameter of the channels and is not larger than the inner diameter of the enlarged diameter portion.

[5] A Fischer-Tropsch synthesis catalyst structure according to any one of the above items [1] to [4], characterized by containing the metal element (M) of the fine metal particles in an amount of 0.5 to 2.5 mass% relative to the Fischer-Tropsch synthesis catalyst structure.

[6] A Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [5], wherein the metal fine particles include Co, Fe, Ni, or an alloy containing at least one of them.

[7] A Fischer-Tropsch synthesis catalyst structure according to any one of the above items [1] to [6], wherein the metal fine particles have an average particle diameter of 0.08 to 30 nm.

[8] A Fischer-Tropsch synthesis catalyst structure according to the above [7], characterized in that the metal fine particles have an average particle diameter of 0.4 to 11.0 nm.

[9] A Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [8], wherein the ratio of the average particle diameter of the fine metal particles to the average inner diameter of the channels is 0.05 to 300.

[10] A Fischer-Tropsch synthesis catalyst structure according to item [9], wherein the ratio of the average particle diameter of the fine metal particles to the average inner diameter of the channels is 0.1 to 30.

[11] A Fischer-Tropsch synthesis catalyst structure according to item [10], wherein the ratio of the average particle diameter of the fine metal particles to the average inner diameter of the channels is 1.4 to 3.6.

[12] A Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [11], wherein the channels have: any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound; and a diameter expanding portion different from any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole,

the average inner diameter of the channel is 0.1 nm-1.5 nm,

the inner diameter of the diameter-expanded portion is 0.5nm to 50 nm.

[13] A Fischer-Tropsch synthesis catalyst structure according to any one of the above items [1] to [12], further comprising at least one type of other metal fine particles held on the outer surface of the support.

[14] A Fischer-Tropsch synthesis catalyst structure according to item [13], characterized in that the at least one metal particulate is present in the support in an amount greater than the amount of the at least one other metal particulate retained on the outer surface of the support.

[15] A Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [14], characterized in that the zeolite-type compound is a silicate compound.

[16] A hydrocarbon production apparatus having the Fischer-Tropsch synthesis catalyst structure according to any one of [1] to [15 ].

[17] A method for producing a Fischer-Tropsch synthesis catalyst structure, comprising:

a firing step of firing a precursor material (B) obtained by impregnating a metal-containing solution into a precursor material (a) for obtaining a support having a porous structure composed of a zeolite-type compound; and

a hydrothermal treatment step of subjecting a precursor material (C) obtained by firing the precursor material (B) to hydrothermal treatment; and

and a step of subjecting the precursor material (C) after the hydrothermal treatment to a reduction treatment.

[18] The method for producing a Fischer-Tropsch synthesis catalyst structure according to item [17], wherein 50 to 500 mass% of a nonionic surfactant is added to the precursor material (A) before the firing step.

[19] The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of [17] and [18], wherein the metal-containing solution is impregnated into the precursor material (A) by adding the metal-containing solution to the precursor material (A) a plurality of times before the firing step.

[20] The method for producing a Fischer-Tropsch synthesis catalyst structure according to any one of [17] to [19], wherein, when the metal-containing solution is impregnated into the precursor material (A) before the firing step, the amount of the metal-containing solution added to the precursor material (A) is adjusted so that the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to the precursor material (A) is 10 to 1000 in terms of the ratio.

[21] The method for producing a Fischer-Tropsch synthesis catalyst structure according to item [17], wherein the precursor material (C) is mixed with a structure directing agent in the hydrothermal treatment step.

[22] The method for producing a Fischer-Tropsch synthesis catalyst structure according to item [17], wherein the hydrothermal treatment step is performed in an alkaline environment.

[23] A method for producing liquid hydrocarbons, which is a method for producing liquid hydrocarbons by synthesizing liquid hydrocarbons from carbon monoxide and hydrogen using a catalyst containing a Fischer-Tropsch synthesis catalyst structure, the method comprising:

a porous support composed of a zeolite-type compound; and

at least one metal particulate present within the carrier,

the carrier has channels that are in communication with each other,

the metal microparticles are present in at least the expanded diameter portion of the channel of the carrier.

Advantageous effects

According to the present invention, it is possible to provide a fischer-tropsch synthesis catalyst structure that can prevent aggregation of fine metal particles with each other, suppress a decrease in catalytic activity, achieve a long life, eliminate the need for complicated replacement work, and achieve resource saving, a method for producing the same, a method for producing hydrocarbons using the catalyst structure, and a hydrocarbon production apparatus having the catalyst structure.

Drawings

Fig. 1 is a schematic view showing an internal structure of a fischer-tropsch synthesis catalyst structure according to an embodiment of the present invention, in which fig. 1 (a) is a perspective view (partially shown in cross section), and 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 of fig. 1, fig. 2 (a) is a view for explaining a sieve function, and fig. 2 (b) is a view for explaining a catalyst function.

Fig. 3 is a flowchart showing an example of a method for manufacturing the fischer-tropsch synthesis catalyst structure of fig. 1.

Fig. 4 is a schematic diagram showing a modification of the fischer-tropsch synthesis catalyst structure of fig. 1.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[ constitution of Fischer-Tropsch Synthesis catalyst Structure ]

Fig. 1 is a view schematically showing a configuration of a fischer-tropsch synthesis catalyst structure (hereinafter, also simply referred to as "catalyst structure") according to an embodiment of the present invention, in which fig. 1 (a) is a perspective view (partially shown in cross section), and fig. 1 (b) is a partially enlarged sectional view. The catalyst structure in fig. 1 is an example thereof, and the shape, size, and the like of each component of the present invention are not limited to fig. 1.

As shown in fig. 1 (a), the catalyst structure 1 includes: a porous support 10 made of a zeolite-type compound; and at least one metal particulate 20 present within the carrier 10.

In the catalyst structure 1, the plurality of metal fine particles 20, … … are included in the porous structure of the support 10. The metal fine particles 20 are catalyst substances having catalytic ability (catalytic activity). The metal fine particles will be described in detail later. The fine metal particles 20 may be metal oxides, metal alloys, or particles containing these composite materials.

The carrier 10 has a porous structure, and preferably has channels 11 communicating with each other by forming a plurality of holes 11a, and … …, as shown in fig. 1 (b). Here, the metal particles 20 are present in at least the channels 11 of the carrier 10, preferably retained in at least the channels 11 of the carrier 10.

With such a configuration, the movement of the fine metal particles 20 in the carrier 10 is restricted, and the aggregation of the fine metal particles 20 and 20 is effectively prevented. As a result, the decrease in the effective surface area of the fine metal particles 20 can be effectively suppressed, and the catalytic activity of the fine metal particles 20 can be maintained for a long period of time. That is, according to the catalyst structure 1, it is possible to suppress a decrease in catalytic activity due to aggregation of the fine metal particles 20, and to achieve a longer life as the catalyst structure 1. Furthermore, by increasing the life of the catalyst structure 1, the frequency of replacement of the catalyst structure 1 can be reduced, the amount of waste of the used catalyst structure 1 can be greatly reduced, and resources can be saved.

In general, when a catalyst structure is used in a fluid (for example, heavy oil, reformed gas such as NOx), an external force may be applied from the fluid. In this case, if the metal fine particles are held only in an attached state on the outer surface of the carrier 10, there is a problem that the metal fine particles are easily detached from the outer surface of the carrier 10 under the influence of an external force from the fluid. In contrast, in the catalyst structure 1, the fine metal particles 20 are present in at least the channels 11 of the carrier 10, and therefore, even when the fine metal particles 20 are affected by an external force of a fluid, the fine metal particles 20 are less likely to be detached from the carrier 10. Namely, it is considered that: when the catalyst structure 1 is in a fluid, the fluid flows into the channels 11 from the pores 11a of the carrier 10, and therefore the velocity of the fluid flowing through the channels 11 is lower than the velocity of the fluid flowing through the outer surfaces of the carrier 10 due to flow path resistance (frictional force). Due to the influence of such flow path resistance, the pressure that the metal fine particles 20 held in the passages 11 receive from the fluid is smaller than the pressure that the metal fine particles receive from the fluid outside the carrier 10. Therefore, the separation of the fine metal particles 20 present in the carrier 10 can be effectively suppressed, and the catalytic activity of the fine metal particles 20 can be stably maintained for a long period of time. It should be noted that: the channel 11 of the carrier 10 has a plurality of bends and branches, and the more complicated three-dimensional structure is inside the carrier 10, the greater the flow path resistance as described above.

Furthermore, the channel 11 preferably has: any one of one-dimensional pores, two-dimensional pores, and three-dimensional pores defined by the framework structure of the zeolite-type compound; and an enlarged diameter portion 12 different from any of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole, in which case, the metal fine particles 20 are preferably present at least in the enlarged diameter portion 12, and more preferably are included at least in the enlarged diameter portion 12. Further, the enlarged diameter portion 12 preferably causes a plurality of holes 11a, 11a constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole to communicate with each other. Thus, since a separate channel different from the one-dimensional hole, the two-dimensional hole, or the three-dimensional hole is provided in the carrier 10, the fine metal particles 20 can further function. The one-dimensional hole referred to herein is a tunnel-type or cage-type hole in which one-dimensional channels are formed, or a plurality of holes (a plurality of one-dimensional channels) in a tunnel-type or cage-type hole in which a plurality of one-dimensional channels are formed. In addition, the two-dimensional hole refers to a two-dimensional hole formed by two-dimensionally connecting a plurality of one-dimensional holes, and the three-dimensional hole refers to a three-dimensional hole formed by three-dimensionally connecting a plurality of one-dimensional holes. This can further restrict the movement of the fine metal particles 20 in the carrier 10, and can further effectively prevent the fine metal particles 20 from being detached and the fine metal particles 20 and 20 from being aggregated with each other. Inclusion means a state in which the metal fine particles 20 are enclosed in the carrier 10. In this case, the fine metal particles 20 and the carrier 10 do not necessarily need to be in direct contact with each other, and the fine metal particles 20 may be indirectly held by the carrier 10 with another substance (for example, a surfactant) interposed between the fine metal particles 20 and the carrier 10.

Fig. 1 (b) shows a case where the fine metal particles 20 are enclosed in the enlarged diameter portion 12, but the present invention is not limited to this configuration, and the fine metal particles 20 may be held in the passage 11 in a state where a part thereof protrudes to the outside of the enlarged diameter portion 12. The fine metal particles 20 may be partially embedded or held by adhesion or the like in a part of the channel 11 other than the enlarged diameter portion 12 (for example, an inner wall portion of the channel 11).

Further, it is preferable that the channel 11 is three-dimensionally formed inside the carrier 10 so as to include a branching portion or a merging portion, and the diameter-expanding portion 12 is provided in the branching portion or the merging portion of the channel 11.

The average inner diameter D of the channels 11 formed in the carrier 10 is calculated from the average of the minor diameter and the major diameter of the holes 11a constituting any one of the one-dimensional holes, the two-dimensional holes, and the three-dimensional holes_FFor example, it is 0.1nm to 1.5nm, preferably 0.5nm to 0.8 nm. Further, the inner diameter D of the enlarged diameter portion 12_EFor example, 0.5nm to 50nm, preferably 1.1nm to 40nm, and more preferably 1.1nm to 3.3 nm. Inner diameter D of enlarged diameter portion 12_EFor example, the pore diameter of the precursor (A) described later and the average particle diameter D of the enclosed metal fine particles 20_C. Inner diameter D of enlarged diameter portion 12_EIs of a size capable of containing the metal particles 20.

The support 10 is composed of a zeolite-type compound. Examples of the zeolite-type compound include: silicate compounds such as zeolite (aluminosilicate), cation-exchange zeolite, and silicalite (silicalite); zeolite-like compounds such as aluminoborate, aluminoarsenate, germanate and the like; and phosphate-based zeolite-like substances such as molybdenum phosphate. Among them, the zeolite-type compound is preferably a silicate compound.

The framework structure of the zeolite-type compound is selected from FAU-type (Y-type or X-type), MTW-type, MFI-type (ZSM-5), FER-type (ferrierite), LTA-type (A-type), MWW-type (MCM-22), MOR-type (mordenite), LTL-type (L-type), BEA-type (beta-type), etc., preferably MFI-type, more preferably ZSM-5. The zeolite-type compound has a plurality of pores formed therein and having pore diameters corresponding to respective framework structures, and for example, the MFI-type compound has a maximum pore diameter of 0.636nm

Average pore diameter of 0.560nm

The average particle diameter D of the fine metal particles 20 is determined by the primary particles of the fine metal particles 20 and the secondary particles formed by the aggregation of the primary particles_CPreferably greater than the average internal diameter D of the channel 11_FAnd is not more than the inner diameter D of the enlarged diameter part 12_E(D_F<D_C≤D_E). Such fine metal particles 20 are preferably present in the enlarged diameter portion 12 in the channel 11 to restrict the movement of the fine metal particles 20 in the carrier 10. Therefore, even when the fine metal particles 20 receive an external force from the fluid, the movement of the fine metal particles 20 in the carrier 10 can be suppressed, and the fine metal particles 20, … … respectively present in the diameter-enlarged portions 12, … … of the channels 11 dispersedly arranged in the carrier 10 can be effectively prevented from contacting each other.

The fine metal particles 20 have an average particle diameter D of either primary particles or secondary particles_CEach of these is preferably 0.08 to 30nm, more preferably 0.1 to less than 25nm, still more preferably 0.4 to 11.0nm, and particularly preferably 0.8 to 2.7 nm. Further, the average particle diameter D of the fine metal particles 20_CRelative to the mean internal diameter D of the channel 11_FRatio (D)_C/D_F) Preferably 0.05 to 300, more preferably 0.1 to 30, further preferably 1.1 to 30, and particularly preferably 14-3.6. The content of the metal element (M) in the fine metal particles 20 is preferably 0.5 to 2.5 mass% with respect to the catalyst structure 1, and more preferably 0.5 to 1.5 mass% with respect to the catalyst structure 1. For example, in the case where the metal element (M) is Co, the content (mass%) of the Co element is represented by { (mass of Co element)/(mass of all elements of the catalyst structure 1) } × 100.

The fine metal particles may be composed of an unoxidized metal, and may be composed of a single metal or a mixture of two or more metals. In the present specification, "metal" (as a material) constituting the metal fine particles means a metal alloy containing a single metal containing one metal element (M) and two or more metal elements (M), and is a generic term for metals containing one or more metal elements.

Examples of such metals include: platinum (Pt), palladium (Pd), ruthenium (Ru), nickel (Ni), cobalt (Co), molybdenum (Mo), tungsten (W), iron (Fe), chromium (Cr), cerium (Ce), copper (Cu), magnesium (Mg), aluminum (Al), and the like, and preferably any one or more of the above as a main component, more preferably ruthenium, nickel, iron, and cobalt, further preferably nickel, iron, and cobalt, and particularly preferably iron and cobalt.

The ratio (atomic ratio Si/M) of silicon (Si) constituting the carrier 10 to the metal element (M) constituting the fine metal particles 20 is preferably 10 to 1000, and more preferably 50 to 200. If the ratio is more than 1000, the activity may be low, and the catalyst material may not be sufficiently effective as the fine metal particles. On the other hand, if the ratio is less than 10, the ratio of the fine metal particles 20 is too large, and the strength of the carrier 10 tends to decrease. The fine metal particles 20 referred to herein are particles held or carried in the carrier 10, and do not include fine metal particles attached to the outer surface of the carrier 10.

[ function of Fischer-Tropsch Synthesis catalyst Structure ]

As described above, the catalyst structure 1 includes: a support 10 having a porous structure; and at least one metal particle 20 present within the carrier. The catalyst structure 1 exhibits the catalytic ability of the fine metal particles 20 by the fine metal particles 20 present in the carrier coming into contact with the fluid. Specifically, the fluid that contacts the outer surface 10a of the catalyst structure 1 flows into the inside of the carrier 10 from the holes 11a formed in the outer surface 10a, is guided into the channels 11, moves through the channels 11, and flows out of the catalyst structure 1 through the other holes 11 a. In the path of the fluid moving through the channels 11, a catalytic reaction based on the metal particles 20 is generated by contact with the metal particles 20 present in the channels 11. In addition, the catalyst structure 1 has a molecular sieve function because the support has a porous structure.

First, the molecular sieve function of catalyst structure 1 will be described with reference to fig. 2 (a). As shown in fig. 2 (a), molecules 15a having a size equal to or smaller than the pore diameter of the pores 11a, in other words, equal to or smaller than the inner diameter of the channels 11 can be impregnated into the carrier 10. On the other hand, the molecules 15b having a size larger than the pore diameter of the pores 11a cannot be impregnated into the carrier 10. In this way, when the fluid contains a plurality of compounds, the reaction of the compounds that cannot enter the carrier 10 can be restricted, and the compounds that enter the carrier 10 can be reacted.

Only a compound composed of molecules having a size not larger than the pore diameter of the pores 11a among the compounds generated in the carrier 10 by the reaction can flow out of the carrier 10 through the pores 11a, and is obtained as a reaction product. On the other hand, if the compound that cannot flow out of the pores 11a to the outside of the carrier 10 is converted into a compound composed of molecules having a size that can flow out of the carrier 10, the compound can flow out of the carrier 10. In this manner, a specific reaction product can be selectively obtained by using the catalyst structure 1.

In the catalyst structure 1, as shown in fig. 2 (b), the fine metal particles 20 are included in the enlarged diameter portion 12 of the channel 11. In the average particle diameter D of the metal fine particles_CGreater than the average internal diameter D of the channel 11_FAnd is smaller than the inner diameter D of the diameter-enlarged part 12_EIn the case of (D)_F<D_C<D_E) Small passages 13 are formed between the fine metal particles and the diameter-enlarged portion 12. Therefore, as shown by the arrows in fig. 2 (b), the fluid and the metal which are immersed in the small channel 13 are minuteAnd (4) contacting the particles. Since each fine metal particle is wrapped in the enlarged diameter portion 12, the movement of the fine metal particles in the carrier 10 is restricted. This prevents the metal microparticles in the carrier 10 from aggregating with each other. As a result, a large contact area between the metal fine particles and the fluid can be stably maintained.

Specifically, when the molecules immersed in the channels 11 come into contact with the metal fine particles 20, the molecules (reformed substance) are reformed by a catalytic reaction. In the present invention, by using the catalyst structure 1, for example, a mixed gas containing hydrogen and carbon monoxide as main components can be used as a raw material to produce hydrocarbons (CH removal)₄) Preferably C₅～C₂₀In particular liquid hydrocarbons (C) which are liquid at normal temperature₅～C₁₆The hydrocarbon (b). This catalytic reaction is carried out at a high temperature of, for example, 180 to 350 ℃, but the fine metal particles 20 are present in the carrier 10, and therefore are less susceptible to heating. In particular, since the fine metal particles 20 are present in the enlarged diameter portion 12, the movement of the fine metal particles 20 in the carrier 10 is more restricted, and the aggregation (sintering) of the fine metal particles 20 is further suppressed. As a result, the reduction in catalytic activity is further suppressed, and the catalyst structure 1 can have a longer life. Further, by using the catalyst structure 1 for a long period of time, the fine metal particles 20 are not bonded to the carrier 10 even if the catalytic activity is lowered, and therefore, the activation treatment (reduction treatment) of the fine metal particles 20 can be easily performed.

[ method for producing Fischer-Tropsch Synthesis catalyst Structure ]

Fig. 3 is a flowchart showing a method for manufacturing the catalyst structure 1 of fig. 1.

(step S1: preparation Process)

As shown in fig. 3, first, a precursor material (a) for obtaining a support having a porous structure made of a zeolite-type compound is prepared. The precursor material (a) is preferably a regular mesoporous substance, and may be appropriately selected depending on the kind (composition) of the zeolite-type compound constituting the support of the catalyst structure.

Here, when the zeolite-type compound constituting the carrier of the catalyst structure is a silicate compound, the regular mesoporous material is preferably a compound containing an Si — O framework in which pores having a pore diameter of 1nm to 50nm are uniformly and regularly developed in one-dimensional, two-dimensional or three-dimensional size. Such a ordered mesoporous material is obtained as various compositions according to synthesis conditions, and specific examples of the compositions include: SBA-1, SBA-15, SBA-16, KIT-6, FSM-16, MCM-41 and the like, wherein MCM-41 is preferred. The pore diameter of SBA-1 is 10nm to 30nm, the pore diameter of SBA-15 is 6nm to 10nm, the pore diameter of SBA-16 is 6nm, the pore diameter of KIT-6 is 9nm, the pore diameter of FSM-16 is 3nm to 5nm, and the pore diameter of MCM-41 is 1nm to 10 nm. Examples of such a regular mesoporous material include: mesoporous silica, mesoporous aluminosilicates, mesoporous metallosilicates, and the like.

The precursor (a) may be any of commercially available products and synthetic products. In the case of synthesizing the precursor material (a), it can be carried out by a known method for synthesizing a regular mesoporous substance. For example, a mixed solution containing a raw material containing a constituent element of the precursor material (a) and a template agent for specifying the structure of the precursor material (a) is prepared, and hydrothermal treatment (hydrothermal synthesis) is performed by adjusting the pH as necessary. Then, the precipitate (product) obtained by the hydrothermal treatment is recovered (for example, filtered), washed and dried as necessary, and further fired, whereby the precursor material (a) as a regular mesoporous substance in a powder form can be obtained. Here, as the solvent of the mixed solution, for example, an organic solvent such as water or alcohol, or a mixed solvent thereof can be used. The raw material is selected depending on the kind of the carrier, and examples thereof include: silica agents such as Tetraethoxysilane (TEOS), fumed silica, quartz sand, and the like. Further, as the template agent, various surfactants, block copolymers and the like can be used, and it is preferably selected according to the kind of the composition of the ordered mesoporous material, and for example, in the case of preparing MCM-41, a surfactant such as cetyltrimethylammonium bromide is preferred. The hydrothermal treatment may be carried out, for example, in a closed vessel under the treatment conditions of 80 to 800 ℃ for 5 to 240 hours and 0 to 2000 kPa. The firing treatment may be carried out, for example, in air under the treatment conditions of 350 to 850 ℃ for 2 to 30 hours.

(step S2: impregnation step)

Next, the prepared precursor material (a) is immersed in a metal-containing solution to obtain a precursor material (B).

The metal-containing solution may be a solution containing a metal component (for example, metal ion) corresponding to the metal element (M) constituting the metal fine particles of the catalyst structure, and may be prepared, for example, by dissolving a metal salt containing the metal element (M) in a solvent. Examples of such metal salts include: metal salts such as chlorides, hydroxides, oxides, sulfates, nitrates, etc., among which nitrates are preferable. As the solvent, for example, an organic solvent such as water or alcohol, or a mixed solvent thereof can be used.

The method for immersing the metal-containing solution in the precursor material (a) is not particularly limited, and for example, it is preferable to add the metal-containing solution to the precursor material (a) in small amounts in a plurality of times while stirring the powdery precursor material (a) before the firing step described later. In addition, from the viewpoint that the metal-containing solution is more likely to infiltrate into the inside of the pores of the precursor material (a), it is preferable to add a surfactant as an additive in advance before adding the metal-containing solution to the precursor material (a). It is considered that such an additive has an effect of covering the outer surface of the precursor material (a), and it suppresses the metal-containing solution added later from adhering to the outer surface of the precursor material (a), and the metal-containing solution is more likely to infiltrate into the inside of 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. Consider that: these surfactants have large molecular sizes and cannot enter the pores of the precursor material (a), and therefore do not adhere to the inside of the pores and do not inhibit the metal-containing solution from entering the inside of the pores. As a method for adding the nonionic surfactant, for example, 50 to 500 mass% of the nonionic surfactant is preferably added to the precursor material (a) before the firing step described later. If the amount of the nonionic surfactant added to the precursor material (a) is less than 50 mass%, the above-described inhibiting effect is difficult to be exhibited, and if the amount of the nonionic surfactant added to the precursor material (a) is more than 500 mass%, the viscosity is excessively increased, which is not preferable. Therefore, the amount of the nonionic surfactant added to the precursor material (a) is set to a value within the above range.

The amount of the metal-containing solution added to the precursor material (a) is preferably adjusted as appropriate in consideration of the amount of the metal element (M) contained in the metal-containing solution impregnated in the precursor material (a) (that is, the amount of the metal element (M) present in the precursor material (B)). For example, the amount of the metal-containing solution added to the precursor material (a) is preferably adjusted so that the ratio (atomic ratio Si/M) of silicon (Si) constituting the precursor material (a) to a metal element (M) contained in the metal-containing solution added to the precursor material (a) is 10 to 1000, more preferably 50 to 200, before the firing step described later. For example, when a surfactant is added as an additive to the precursor material (a) before the metal-containing solution is added to the precursor material (a), the content of the metal element (M) in the metal fine particles can be set to 0.5 to 2.5 mass% relative to the catalyst structure by setting the amount of the metal-containing solution added to the precursor material (a) to 50 to 200 in terms of the atomic ratio Si/M. In the state of the precursor material (B), if the metal concentration of the metal-containing solution, the presence or absence of the additive, other conditions such as temperature and pressure are the same, the amount of the metal element (M) present in the pores thereof is substantially proportional to the amount of the metal-containing solution added to the precursor material (a). Further, the amount of the metal element (M) present in the precursor material (B) is in proportional relation to the amount of the metal element constituting the metal fine particles present in the carrier of the catalyst structure. Therefore, by controlling the amount of the metal-containing solution added to the precursor material (a) within the above range, the metal-containing solution can be sufficiently impregnated into the pores of the precursor material (a), and the amount of the metal fine particles present in the support of the catalyst structure can be adjusted.

After the precursor material (a) is immersed in the metal-containing solution, a cleaning treatment may be performed as needed. As the cleaning solution, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Further, it is preferable that the metal-containing solution is immersed in the precursor material (a) and, after a cleaning treatment is performed as necessary, a drying treatment is further performed. Examples of the drying treatment include natural drying at about evening-out and high-temperature drying at 150 ℃. When the firing treatment described later is performed in a state where a large amount of moisture contained in the metal-containing solution or moisture in the cleaning solution remains in the precursor (a), the skeleton structure of the regular mesoporous material as the precursor (a) may be broken, and therefore, it is preferable to sufficiently dry the precursor (a).

(step S3: firing Process)

Next, a precursor material (B) obtained by impregnating a precursor material (a) for obtaining a support having a porous structure composed of a zeolite-type compound with a metal-containing solution is fired to obtain a precursor material (C).

The firing treatment is preferably carried out in air at a temperature of 350 to 850 ℃ for 2 to 30 hours, for example. By such firing treatment, the metal component crystals impregnated into the pores of the regular mesoporous material grow, and metal fine particles are formed in the pores.

(step S4: hydrothermal treatment Process)

Next, a mixed solution in which the precursor material (C) and the structure directing agent are mixed is prepared, and the precursor material (C) obtained by firing the precursor material (B) is subjected to hydrothermal treatment to obtain the catalyst structure.

The structure-directing agent is a template agent for defining the framework structure of the support of the catalyst structure, and for example, a surfactant can be used. The structure-directing agent is preferably selected according to the skeletal structure of the support of the catalyst structure, and is preferably a surfactant such as tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), tetrapropylammonium bromide (TPABr), or the like.

The mixing of the precursor material (C) and the structure-directing agent may be performed in the present hydrothermal treatment step, or may be performed 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, and the solvent may be mixed at the same time, or the precursor material (C) and the structure-directing agent may be dispersed in the solvent in the respective solutions and then the respective dispersed solutions may be mixed. As the solvent, for example, an organic solvent such as water or alcohol, or a mixed solvent thereof can be used. It is preferable that the pH of the mixed solution is adjusted in advance with an acid or an alkali before the hydrothermal treatment.

The hydrothermal treatment can be carried out by a known method, and is preferably carried out in a closed vessel under treatment conditions of, for example, 80 to 800 ℃ for 5 to 240 hours and 0 to 2000 kPa. Further, it is preferable to perform hydrothermal treatment in an alkaline environment. Although the reaction mechanism is not necessarily clear here, when the precursor material (C) is subjected to hydrothermal treatment as a raw material, the skeleton structure of the regular mesoporous material as the precursor material (C) is gradually destroyed, but the position of the metal fine particles inside the pores of the precursor material (C) is substantially maintained, and a new skeleton structure (porous structure) serving as a support of the catalyst structure is formed by the action of the structure-directing agent. The catalyst structure obtained in this way comprises a support having a porous structure and metal fine particles present in the support, the support further has channels which communicate with each other through the porous structure of the support, and at least a part of the metal fine particles are present in the channels of the support. In the present embodiment, in the hydrothermal treatment step, a mixed solution in which the precursor material (C) and the structure-directing agent are mixed is prepared, and the hydrothermal treatment is performed on the precursor material (C), but the present invention is not limited thereto, and the hydrothermal treatment may be performed on the precursor material (C) without mixing the precursor material (C) and the structure-directing agent.

It is preferable that the precipitate (catalyst structure) obtained after the hydrothermal treatment is recovered (e.g., filtered), and then washed, dried, and fired as necessary. 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 at about evening-out and high-temperature drying at 150 ℃. When the calcination treatment is performed in a state where a large amount of water remains in the precipitate, the skeleton structure of the carrier serving as the catalyst structure may be broken, and therefore, it is preferable to sufficiently dry the catalyst structure. The firing treatment may be performed, for example, in air under the treatment conditions of 350 to 850 ℃ for 2 to 30 hours. By such a firing treatment, the structure directing agent attached to the catalyst structure is burned off. Further, depending on the purpose of use, the catalyst structure may be used as it is without subjecting the recovered precipitate to firing treatment. For example, when the environment in which the catalyst structure is used is a high-temperature environment such as an oxidizing environment, the structure-directing agent is burned off by exposure to the use environment for a certain period of time, and the catalyst structure can be obtained as it is as in the case of performing the firing treatment.

The above-described manufacturing method is an example of a case where the metal element (M) contained in the metal-containing solution impregnated in the precursor material (a) is a metal species (for example, a noble metal) that is difficult to be oxidized.

In the case where the metal element (M) contained in the metal-containing solution impregnated in the precursor material (a) is a metal species (for example, Fe, Co, Cu, or the like) that is easily oxidized, it is preferable to perform a reduction treatment on the precursor material (C) after the hydrothermal treatment step. When the metal element (M) contained in the metal-containing solution is a metal species that is easily oxidized, the metal component is oxidized by the heat treatment in the steps (steps S3 to S4) after the impregnation treatment (step S2). Therefore, the metal oxide fine particles are present in the carrier formed in the hydrothermal treatment step (step S4). Therefore, in order to obtain a catalyst structure in which metal fine particles are present in a carrier, it is desirable to perform a calcination treatment of the recovered precipitate after the hydrothermal treatment and further perform a reduction treatment in a reducing gas atmosphere such as hydrogen gas. By performing the reduction treatment, the metal oxide fine particles present in the carrier are reduced to form metal fine particles corresponding to the metal element (M) constituting the metal oxide fine particles. As a result, a catalyst structure in which the metal fine particles are present in the carrier can be obtained. For example, when the environment in which the catalyst structure is used is a reducing environment, the metal oxide fine particles are reduced by exposure to the reducing environment for a certain period of time, and therefore the catalyst structure similar to that in the reducing treatment can be obtained, and therefore the catalyst structure can be used as it is with the oxide fine particles present in the carrier.

[ modification of Fischer-Tropsch Synthesis catalyst Structure ]

Fig. 4 is a schematic diagram showing a modification of the catalyst structure 1 of fig. 1. The catalyst structure 1 of fig. 1 includes the carrier 10 and the fine metal particles 20 present in the carrier 10, but is not limited to this configuration, and for example, as shown in fig. 4, the catalyst structure 2 may further include another fine metal particles 30 held on the outer surface 10a of the carrier 10.

The metal particles 30 are catalyst materials that exert one or more catalytic capabilities. The other metal particles 30 may have the same or different catalytic ability as the metal particles 20. In the case where both the fine metal particles 20 and 30 are catalyst substances having the same catalytic ability, the material of the other fine metal particles 30 may be the same as or different from the material of the fine metal particles 20. According to the present configuration, the content of the metal fine particles held in the catalyst structure 2 can be increased, and the catalytic activity of the metal fine particles can be further promoted.

In this case, it is preferable that the content of the metal fine particles 20 present in the carrier 10 is more than the content of the other metal fine particles 30 held on the outer surface 10a of the carrier 10. Thus, the catalytic ability of the metal fine particles 20 held in the carrier 10 becomes a dominant function, and the catalytic ability of the metal fine particles is stably exhibited.

Further, the present invention provides a method for producing liquid hydrocarbons, which comprises synthesizing liquid hydrocarbons from carbon monoxide and hydrogen using a catalyst. Such a catalyst comprises a fischer-tropsch synthesis catalyst structure 1, and the fischer-tropsch synthesis catalyst structure 1 includes: a porous support 10 made of a zeolite-type compound; and at least one metal fine particle 20 present in the carrier 10, the carrier 10 having channels 11 communicating with each other, the metal fine particle 20 being present in at least the diameter-enlarged portion 12 of the channel 11 of the carrier 10. That is, the present invention provides a method for producing liquid hydrocarbons, in which liquid hydrocarbons are synthesized from carbon monoxide and hydrogen, using the fischer-tropsch synthesis catalyst structure described above.

The raw material for carrying out the process for producing liquid hydrocarbons by the fischer-tropsch synthesis reaction is not particularly limited as long as it is a synthesis gas containing molecular hydrogen and carbon monoxide as main components, but a synthesis gas having a hydrogen/carbon monoxide molar ratio of 1.5 to 2.5 is preferred, and a synthesis gas having a molar ratio of 1.8 to 2.2 is more preferred. The reaction conditions for the FT synthesis reaction are also not particularly limited, and may be performed under known conditions. For example, the reaction temperature is 200 to 500 ℃, preferably 200 to 350 ℃, and the pressure is preferably 0.1 to 3.0MPa (absolute pressure).

In the Fischer-Tropsch synthesis reaction, the reaction process as the Fischer-Tropsch synthesis may be carried out by a known process such as a fixed bed, a supercritical fixed bed, a slurry bed, a fluidized bed, or the like. Preferred examples of the process include a fixed bed, a supercritical fixed bed, and a slurry bed.

Further, in the present invention, there can be provided a hydrocarbon production apparatus having the catalyst structure described above. Such a hydrocarbon production apparatus is not particularly limited as long as it is an apparatus for performing fischer-tropsch synthesis using the catalyst structure, and for example, a production apparatus generally used such as an FT synthesis reactor or an FT synthesis column can be used. By using the catalyst structure of the present invention in such a hydrocarbon production apparatus, the same effects as described above can be obtained in the production apparatus.

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