Catalyst for ethylene production, method for producing catalyst for ethylene production, and method for producing ethylene

Abstract

To provide a catalyst for ethylene production that utilizes carbon monoxide and hydrogen as raw materials and enables ethylene to be produced with high selectivity, a method for producing the catalyst for ethylene production, and a method for producing ethylene using the catalyst for ethylene production.SOLUTION: A catalyst for ethylene production comprises (i) a metal catalyst including manganese and iron, serving as a first catalyst, and at least one selected from magnesium, calcium, strontium, barium, and sodium, serving as a second catalyst, and (ii) a zeolite catalyst including at least one zeolite, serving as a third catalyst.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a catalyst for ethylene production, a method for producing the catalyst for ethylene production, and a method for producing ethylene.

Background Art

[0002] Lower olefins (ethylene, propylene, butene) have conventionally been produced from petroleum as a raw material. However, due to problems such as depletion of petroleum resources and the geographical distribution of resources, a technology for producing lower olefins from synthesis gas (a mixed gas containing at least H2 and CO) derived from natural gas, coal, etc. as a raw material has been desired. In the production of lower olefins using synthesis gas as a raw material, a catalyst is generally used, and research on the catalyst has been widely conducted, and catalysts for lower olefin production are also known (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the catalysts described in Patent Documents 1 and 2 above could not convert the H2 / CO mixed gas into ethylene with high selectivity. Therefore, there is a desire to provide a method capable of converting the H2 / CO mixed gas into ethylene with high selectivity.

[0005] An object of the present invention is to provide a catalyst for ethylene production that can produce ethylene with high selectivity using carbon monoxide and hydrogen as raw materials, a method for producing the catalyst for ethylene production, and a method for producing ethylene using the catalyst for ethylene production.

Means for Solving the Problems

[0006] In order to solve the above problems, the present inventors conducted intensive studies and as a result, found that the above problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following. (1) (i) A metal catalyst containing manganese and iron as a first catalyst and at least one or more of magnesium, calcium, strontium, barium, and sodium as a second catalyst, (ii) A zeolite catalyst containing at least one or more zeolites as a third catalyst, the ethylene production catalyst. (2) The ethylene production catalyst according to (1), wherein the selectivity of ethylene is 50% or more. (3) The ethylene production catalyst according to (1) or (2), which is a catalyst using a methanol-to-olefin (MTO) reaction pathway. (4) The ethylene production catalyst according to any one of (1) to (3), wherein the metal catalyst is composed of amorphous metal catalyst particles. (5) The ethylene production catalyst according to any one of (1) to (4), wherein the content of the second catalyst with respect to the total mass of the first catalyst and the second catalyst is 1 to 50% by mass. (6) The ethylene production catalyst according to any one of (1) to (5), wherein the ratio of manganese to iron in the first catalyst is manganese:iron = 1:10 to 10:1. (7) The ethylene production catalyst according to any one of (1) to (6), wherein the average particle diameter of the metal catalyst particles in the metal catalyst is 0.1 to 1000 μm. (8) The ethylene production catalyst according to any one of (1) to (7), wherein the third catalyst is one or more selected from ITQ zeolite, ZSM-5 zeolite, SAPO zeolite, FER zeolite, and MOR zeolite. (9) The ethylene production catalyst according to (8), wherein the ITQ zeolite is ITQ-2 zeolite. (10) The ethylene production catalyst according to any one of (1) to (9), further comprising, as a fourth catalyst, one or more selected from V, Cr, Zr, Cu, Ni, Ce, Pd, Ru, Rh, Al, Si, Pt, Mo, and Ga. (11) A method for producing the ethylene production catalyst according to any one of (1) to (10), comprising: (i) a metal catalyst containing a mixture obtained by mixing the first catalyst and the second catalyst; (ii) mixing with the third catalyst A method for producing an ethylene production catalyst, comprising a step of mixing. (12) A method for producing ethylene, comprising contacting a raw material gas containing carbon monoxide and hydrogen with the ethylene production catalyst according to any one of (1) to (10) to produce ethylene. (13) A method for producing ethylene according to (12), comprising contacting a raw material gas containing carbon monoxide and hydrogen with the ethylene production catalyst according to any one of claims 1 to 4, and producing ethylene via methanol by a methanol-to-olefin (MTO) reaction pathway.

Advantages of the Invention

[0007] According to the present invention, there can be provided an ethylene production catalyst capable of producing ethylene with high selectivity using carbon monoxide and hydrogen as raw materials, a method for producing the ethylene production catalyst, and a method for producing ethylene using the ethylene production catalyst.

Brief Description of the Drawings

[0008]

Figure 1

Embodiments for Carrying Out the Invention

[0009] (Ethylene Production Catalyst) The ethylene production catalyst of the present invention catalyzes the synthesis reaction of ethylene using carbon monoxide and hydrogen as raw materials. The inventors have found that in a catalyst for ethylene production containing a metal catalyst and a zeolite catalyst, by using a metal catalyst comprising a first catalyst containing manganese (Mn) and iron (Fe) and a second catalyst containing at least one of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and sodium (Na), ethylene can be produced with a high selectivity of 50% or more. That is, the catalyst for ethylene production of the present invention is “(i) a metal catalyst comprising manganese and iron as the first catalyst and at least one of magnesium, calcium, strontium, barium, and sodium as the second catalyst, (ii) a zeolite catalyst containing at least one zeolite as the third catalyst”, a catalyst for ethylene production.

[0010] In addition, the inventors have found that a metal catalyst obtained by mixing the first catalyst and the second catalyst and complexing the first catalyst and the second catalyst can produce methanol with high selectivity using carbon monoxide and hydrogen as raw materials. The catalyst for ethylene production of the present invention is a catalyst for producing ethylene via methanol by the methanol-to-olefins (MTO) reaction pathway. Since the catalyst for ethylene production of the present invention is not a catalyst for producing ethylene by the Fischer-Tropsch (FT) reaction, CO2, which is a by-product in the FT reaction, is not generated. Since ethylene can be produced without generating CO2, the catalyst for ethylene production of the present invention has high utility value.

[0011] Furthermore, the inventors have found that the metal catalyst obtained by complexing the first catalyst and the second catalyst is composed of amorphous metal catalyst particles. The fact that the metal catalyst is in this amorphous state is also considered to contribute to satisfying the high selectivity of the ethylene selectivity of 50% or more.

[0012] As described above, the catalyst for ethylene production of the present invention contains a metal catalyst and a zeolite catalyst. Among them, the metal catalyst includes a first catalyst containing manganese (Mn) and iron (Fe), and a second catalyst containing at least one or more of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and sodium (Na).

[0013] In addition, the catalyst for ethylene production of the present invention can further include a fourth catalyst containing one or more metals selected from vanadium (V), chromium (Cr), zirconium (Zr), copper (Cu), nickel (Ni), cerium (Ce), palladium (Pd), ruthenium (Ru), rhodium (Rh), aluminum (Al), silicon (Si), platinum (Pt), molybdenum (Mo), and gallium (Ga).

[0014] The metal catalyst catalyzes the conversion of carbon monoxide and hydrogen to methanol, and the zeolite catalyst mainly catalyzes the conversion of methanol to ethylene. Since the catalyst for ethylene production of the present invention is a composite catalyst including a metal catalyst composed of a first catalyst, a second catalyst, and optionally a fourth catalyst, and a zeolite catalyst, it is a catalyst capable of producing ethylene via methanol through the methanol-to-olefin (MTO) reaction pathway from carbon monoxide and hydrogen.

[0015] <Metal catalyst> The metal catalyst includes a first catalyst containing manganese (Mn) and iron (Fe), and a second catalyst containing at least one or more of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and sodium (Na).

[0016] <<First catalyst>> As long as the first catalyst contains manganese (Mn) and iron (Fe) as catalyst components, its composition is not particularly limited, and oxides, halides, nitrates, carbonates, acetates, ammonium salts, oxo acids, oxo acid salts, etc. can be used alone or in combination of two or more.

[0017] Specifically, examples of manganese contained in the first catalyst include manganese(II) oxide, manganese(IV) oxide, manganese(II) chloride, manganese(II) fluoride, manganese(II) bromide, manganese(II) iodide, manganese(II) acetate, manganese(II) nitrate, manganese(II) sulfate, manganese(II) carbonate, manganese(II) phosphate, manganese(II) perchlorate, manganese(II) borate, potassium permanganate, manganese(II) acetylacetonate, manganese(II) acetate, manganese(III) acetylacetonate, manganese(III) acetate, etc. Among these, one of them can be used alone, or two or more of them can be used in combination.

[0018] Examples of iron contained in the first catalyst include iron(II), iron(II) oxide, iron(III) oxide, iron(II,III) oxide, iron(II) chloride, iron(III) chloride, iron(III) fluoride, iron(II) bromide, iron(III) bromide, iron(II) iodide, iron(II) acetate, iron(III) nitrate, iron(II) sulfate, iron(III) sulfate, iron(II) carbonate, iron(III) phosphate, iron(II) perchlorate, iron(III) perchlorate, iron(II) stearate, iron(II) tetrafluoroborate, iron(II) borate, iron(II) trifluoromethanesulfonate, iron(II) dimethyldithiocarbamate, iron(II) diethyldithiocarbamate, iron(II) chloride (N,N,N’,N’-tetramethylethylenediamine), iron(II) acetylacetonate, iron(II) methoxide, and bis[bis(trimethylsilyl)amide]iron, etc. Among these, one of them can be used alone, or two or more of them can be used in combination.

[0019] <<Second Catalyst>> Magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and sodium (Na) contained in the second catalyst are not particularly limited, and metals, metal-containing oxides, halides, nitrates, carbonates, acetates, ammonium salts, oxoacids, oxoacid salts, etc. can be used alone or in combination of two or more.

[0020] Specifically, examples of the catalyst components of the second catalyst include magnesium(II) oxide, calcium(II) oxide, strontium(II) oxide, barium(II) oxide, sodium(I) oxide, etc. Among these, one kind can be used alone, or two or more kinds can be used in combination.

[0021] <<Content Ratios of Various Components of the Metal Catalyst>> The content rate of the second catalyst with respect to the total mass of the first catalyst and the second catalyst is preferably 1 to 50% by mass. In order to produce ethylene with a high selectivity, it is necessary to necessarily contain a second catalyst in addition to the first catalyst in the metal catalyst. Furthermore, setting the content ratio of the second catalyst in the metal catalyst within the above-mentioned range is effective for producing ethylene with a high selectivity. Also, the ratio of manganese to iron in the first catalyst is preferably manganese:iron = 1:10 to 10:1.

[0022] The metal catalyst is mainly composed of manganese, iron, and at least one of magnesium, calcium, strontium, barium, and sodium. However, for example, other compounds and the like resulting from the production of the metal catalyst may be contained in the metal catalyst.

[0023] The form of the metal catalyst is not particularly limited. For example, it may be granular or film-like. When the metal catalyst is granular, it is preferably small in particle size. By having a small particle size, the surface area of the catalyst increases, and the conversion from carbon monoxide and hydrogen to methanol can be efficiently carried out.

[0024] When the metal catalyst is granular, the average particle diameter of the metal catalyst particles is not particularly limited. For example, it is preferably from 0.001 to 1000 μm, more preferably from 0.01 to 500 μm, and even more preferably from 0.01 μm to 10 μm or less. If the average particle diameter is within the above range, the mass transfer between the first to fourth catalysts is accelerated, and the flow resistance of the raw material gas can be maintained low. The average particle diameter can be determined, for example, by X-ray diffraction method.

[0025] The specific surface area of the metal catalyst is not particularly limited. For example, it is preferably 0.01 m 2 / g or more and 2000 m 2 / g or less, more preferably 0.1 m 2 / g or more and 1000 m 2 / g or less, even more preferably 0.5 m 2 / g or more and 500 m 2 / g or less. If the specific surface area is within the above range, active sites for the reaction of hydrogen and carbon monoxide can be sufficiently supplied, and the generation of a partial pressure difference between carbon monoxide and hydrogen within the metal catalyst can be suppressed. Thereby, the conversion of carbon monoxide and hydrogen to methanol can be efficiently performed. The specific surface area of the catalyst can be calculated, for example, by the Brunauer-Emmett-Teller (BET) method.

[0026] The content of the metal catalyst is not particularly limited. For example, based on the total amount of the catalyst for ethylene production, it is preferably 1% by mass or more and 95% by mass or less, more preferably 2% by mass or more and 80% by mass or less, and even more preferably 10% by mass or more and 70% by mass or less.

[0027] The metal catalyst is preferably obtained by complexing metal salts and the like contained in the metal catalyst at the molecular level or nano level by means such as coprecipitation. By complexing the first catalyst and the second catalyst at the molecular level or nano level, the conversion of carbon monoxide and hydrogen to methanol can be efficiently performed.

[0028] <Zeolite catalyst> The catalyst for ethylene production of the present invention includes a zeolite catalyst containing at least one or more zeolites as the third catalyst component. There is no particular limitation on the type of zeolite. For example, one or more zeolites selected from ITQ zeolite, ZSM-5 zeolite, SAPO zeolite, FER zeolite, and MOR zeolite can be mentioned. Among them, ITQ zeolite, ZSM-5 zeolite, and FER zeolite are preferable, ITQ zeolite and ZSM-5 zeolite are more preferable, and ITQ zeolite is even more preferable.

[0029] <<ITQ zeolite>> Examples of the ITQ zeolite include ITQ-2 zeolite. Examples of ITQ zeolites other than ITQ-2 include zeolites such as ITQ-1, ITQ-3, ITQ-4, ITQ-6, ITQ-7, ITQ-8, ITQ-9, ITQ-10, ITQ-13, ITQ-17, ITQ-21, ITQ-22, ITQ-24, ITQ-27, ITQ-28, ITQ-29, ITQ-30, ITQ-32, ITQ-37, and ITQ-39. The ITQ zeolite can be used alone or in combination of two or more of the above-mentioned ITQ zeolites. Among the ITQ zeolites, it is more preferable that the ITQ zeolite is ITQ-2 zeolite.

[0030] <<<ITQ-2 zeolite>>> ITQ-2 is a nanosheet-like zeolite having two-dimensional pores composed of two types of pores, a 10-membered ring and a 12-membered ring, which do not intersect with each other, obtained by swelling and exfoliating the interlayer of the layered zeolite precursor MCM-22(P) using a strong alkali such as sodium hydroxide and then firing. It can be obtained, for example, by the method described in International Publication No. 2009 / 136547.

[0031] The molar ratio of silicon atoms to aluminum atoms (Si / Al ratio) in ITQ-2 zeolite is not particularly limited and is, for example, 10 or more and 1000 or less, preferably 20 or more and 900 or less. If the Si / Al ratio is within the above range, it is excellent in heat resistance and reaction selectivity, and in particular, the conversion from methanol to ethylene can be efficiently carried out.

[0032] <<ZSM-5 zeolite>> ZSM-5 (Zeolite Socony Mobil-5) zeolite is an aluminosilicate zeolite with a framework structure code of MFI type in the database of the International Zeolite Association, which has three-dimensional pores composed of 10-membered rings.

[0033] The molar ratio of silicon atoms to aluminum atoms (Si / Al ratio) in ZSM-5 zeolite is not particularly limited and is, for example, 10 or more and 1000 or less, preferably 20 or more and 900 or less. If the Si / Al ratio is within the above range, it is excellent in heat resistance and reaction selectivity, and in particular, the conversion from methanol to ethylene can be efficiently carried out.

[0034] <<SAPO zeolite>> SAPO zeolite is a silicoaluminophosphate-type zeolite. SAPO zeolite is not particularly limited, and examples include zeolites such as SAPO-5, SAPO-11, SAPO-17, SAPO-18, SAPO-31, SAPO-34, SAPO-35, SAPO-41, SAPO-42, and SAPO-44. One of these can be used alone, or two or more can be used in combination.

[0035] <<FER zeolite>> FER zeolite is an aluminosilicate zeolite with a framework structure code of FER type in the database of the International Zeolite Association.

[0036] <<MOR Zeolite>> The MOR zeolite is an aluminosilicate zeolite with a framework structure code of MOR type, which is database-registered by the International Zeolite Association.

[0037] The average particle size of the zeolite catalyst is not particularly limited. For example, it is 0.01 μm or more and 1000 μm or less, preferably 0.02 μm or more and 200 μm or less, and more preferably 0.05 μm or more and 100 μm or less. If the average particle size is within the above range, the mass transfer between the first to fourth catalysts can be accelerated, and the flow resistance of the raw material gas can be maintained low.

[0038] The specific surface area of the zeolite catalyst is not particularly limited. For example, it is 1 m 2 / g or more and 1000 m 2 / g or less, preferably 10 m 2 / g or more and 800 m 2 / g or less, and more preferably 100 m 2 / g or more and 700 m 2 / g or less. If the specific surface area is within the above range, active sites for the reaction of methanol and the synthesis of ethylene can be sufficiently supplied.

[0039] The content of the zeolite catalyst is not particularly limited. Based on the total amount of the catalyst for ethylene production, for example, it is 5% by mass or more and 99% by mass or less, preferably 20% by mass or more and 98% by mass or less, and more preferably 30% by mass or more and 90% by mass or less.

[0040] From the viewpoint of further enhancing the catalytic activity, the catalyst for ethylene production of the present invention may further contain a fourth catalyst in addition to the metal catalyst containing the above-described first and second catalysts and the zeolite catalyst which is the third catalyst.

[0041] <Fourth Catalyst> The fourth catalyst contains, as a catalyst component, at least one of vanadium (V), chromium (Cr), zirconium (Zr), copper (Cu), nickel (Ni), cerium (Ce), palladium (Pd), ruthenium (Ru), rhodium (Rh), aluminum (Al), silicon (Si), platinum (Pt), molybdenum (Mo), and gallium (Ga).

[0042] V, Cr, Zr, Cu, Ni, Ce, Pd, Ru, Rh, Al, Si, Pt, Mo, and Ga contained in the fourth catalyst are not particularly limited, and metals, metal-containing oxides, halides, nitrates, carbonates, acetates, ammonium salts, oxoacids, oxoacid salts, etc. can be used alone or in combination of two or more.

[0043] Specifically, examples of the catalyst component of the fourth catalyst include chromium(III) oxide, zirconium(IV) oxide, copper(II) oxide, nickel(II) oxide, cerium(IV) oxide, palladium(II) oxide, ruthenium(V) oxide, rhodium(III) oxide, aluminum(III) oxide, silicon dioxide, platinum(IV) oxide, molybdenum(VI) oxide, gallium(III) oxide, platinum, etc., and one of these can be used alone or in combination of two or more.

[0044] The fourth catalyst is mainly composed of the above-mentioned metal compounds containing at least one of V, Cr, Zr, Cu, Ni, Ce, Pd, Ru, Rh, Al, Si, Pt, Mo, and Ga, but other compounds, etc. resulting from the production of the fourth catalyst may be contained in the fourth catalyst.

[0045] The form of the fourth catalyst is not particularly limited, and for example, it may be granular or film-like. When the fourth catalyst is granular, it is preferably small in particle size. By having a small particle size, active sites can be sufficiently supplied, and the conversion of carbon monoxide and hydrogen to methanol can be efficiently carried out.

[0046] The average particle diameter and specific surface area of the fourth catalyst are not particularly limited, and can be, for example, values within the preferable ranges described for the above metal catalyst.

[0047] When the fourth catalyst is included, the content of the fourth catalyst is not particularly limited. For example, based on the total weight of the first catalyst, the second catalyst, and the fourth catalyst, it can be 0.01% by mass or more and 99% by mass or less, preferably 0.1% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 50% by mass or less.

[0048] The fourth catalyst is preferably complexed with the first catalyst and the second catalyst at the molecular level or nanolevel by using means such as coprecipitation. By complexing the first catalyst, the second catalyst, and the fourth catalyst at the molecular level or nanolevel, the conversion from carbon monoxide and hydrogen to ethylene via methanol can be efficiently carried out. The preferable ranges of the average particle diameter and specific surface area of the metal catalyst formed by complexing the first catalyst, the second catalyst, and the fourth catalyst can also be the same ranges as those described for the above metal catalyst.

[0049] <Any other optional components> From the perspective of improving the moldability, the ethylene production catalyst may contain any other optional components such as a molding aid as long as the effects of the present invention are not impaired. The molding aid may be at least one selected from the group consisting of, for example, thickeners, surfactants, water retention agents, plasticizers, binder raw materials, and the like. Further, the ethylene production catalyst may contain other useful components as long as the effects of the present invention are not impaired.

[0050] As described above, the ethylene production catalyst of the present invention includes a metal catalyst containing the first and second catalysts and a zeolite catalyst as the third catalyst. Further, in the ethylene production catalyst, a fourth catalyst may be included in addition to the first to third catalysts.

[0051] In the catalyst for ethylene production, the composite state of the catalyst is not particularly limited. For example, when the first to fourth catalysts are granular, they can be physically mixed. Alternatively, when the first to fourth catalysts are in the form of a film, the first to fourth catalysts may be laminated. Even when the catalyst for organic compound production of the present invention contains any fourth catalyst, it can be in the above-described composite state.

[0052] In order to optimize the ratio of the content of the zeolite catalyst (total amount of the third catalyst) to the content of the metal catalyst (total amount of the first and second catalysts and any fourth catalyst) during production, it can be achieved by adjusting the mass during the mixing of the first to fourth catalysts. In the catalyst after mixing, the ratio can be determined, for example, using the scanning high-frequency inductively coupled plasma method (ICP).

[0053] The catalyst for ethylene production of the present invention described above uses carbon monoxide and hydrogen as raw materials and can obtain ethylene with high selectivity.

[0054] <Properties of the catalyst> <<Ethylene selectivity> When using the catalyst for ethylene production of the present invention, ethylene can be produced with a high selectivity of 50% or more. The ethylene selectivity of the catalyst for ethylene production of the present invention is 50% or more as described above, preferably 60% or more, and more preferably 70% or more. As described in the examples to be described later, in Example 3 using FER as the zeolite catalyst in the catalyst for ethylene production, the ethylene selectivity was 73.7%, and in Examples 1 using ITQ-2 and Example 2 using ZSM-5, the ethylene selectivity was 100%. Thus, the catalyst for ethylene production of the present invention exhibits high ethylene selectivity. In addition, the ethylene selectivity can be determined as follows. A reaction product obtained by bringing a raw material gas containing carbon monoxide and hydrogen into contact with the catalyst for ethylene production of the present invention and reacting it is analyzed by gas chromatography. From the concentration of each component obtained by the analysis, the selectivity (%) of ethylene is calculated by the following formula.

[0055]

Number

[0056] <<MTO reaction pathway>> The catalyst for ethylene production of the present invention is a catalyst that produces ethylene via methanol by the methanol-to-olefin (MTO) reaction pathway. Since the catalyst for ethylene production of the present invention is not a catalyst for producing ethylene by the Fischer-Tropsch (FT) reaction, CO2, which is a by-product in the FT reaction, does not occur. Since ethylene can be produced without generating CO2, the catalyst for ethylene production of the present invention has high utility value. The metal catalyst in the catalyst for ethylene production of the present invention can produce methanol with high selectivity. And ethylene can be produced from methanol with high selectivity by the zeolite catalyst in the catalyst for ethylene production of the present invention. The above Patent Document 1 aims to reduce the selectivity of CO2 when producing lower olefins by the Fischer-Tropsch (FT) reaction. However, in Example 1 of Patent Document 1, the selectivity of lower olefins is described as 41.2%. Further, the above Patent Document 2 aims to shorten the activation time of the catalyst in the Fischer-Tropsch (FT) reaction (see

[0012] ), but in the result when using "FeNa + ZSM-5(80)" in Table 1 of Patent Document 2, the C2-C4 hydrocarbon distribution is described as 49%. Thus, Patent Document 1 and Patent Document 2 are methods for producing lower olefins by the Fischer-Tropsch (FT) reaction. In Patent Document 1 and Patent Document 2, ethylene cannot be produced with high selectivity. On the other hand, when the catalyst for ethylene production of the present invention is used, as shown in the following examples, the selectivity of ethylene exceeds 70% in any of the examples, and ethylene can be produced with a very high selectivity.

[0057] <<Amorphous state>> The metal catalyst in the catalyst for ethylene production of the present invention is composed of amorphous metal catalyst particles. Iron (Fe), which is the first catalyst in the metal catalyst, usually contributes to the Fischer-Tropsch (FT) reaction. However, in the present invention, iron (Fe) is mixed with manganese (Mn) of the first catalyst and the second catalyst at the atomic level, and since the metal catalyst particles exist in an amorphous state, it is presumed that the metal catalyst according to the present invention is a catalyst that undergoes a methanol-to-olefin (MTO) reaction rather than a Fischer-Tropsch (FT) reaction. Here, the fact that the metal catalyst particles exist in an amorphous state means that iron (Fe) and manganese (Mn) of the first catalyst and the second catalyst are mixed at the atomic level, and as a result, it does not show a specific X-ray diffraction (XRD) pattern such as that of a metal oxide. If X-ray diffraction (XRD) is measured and no diffraction peak is observed, it can be determined that it is in an amorphous state. Note that the absence of a diffraction peak means, for example, that the diffraction peak is below the detection limit. For example, it means that it is below the detection limit (S / N ratio of 3). For example, by confirming that there is no diffraction peak derived from Fe oxide at 24.2, 33.2, 35.1 degrees, no diffraction peak derived from Mg oxide at 32.96, 37.1, 62.10, 68.40 degrees, no diffraction peak derived from Mn oxide at 28.5, 37.5, 56.5 degrees, etc., it can be confirmed whether the metal catalyst particles are in an amorphous state. An example of the measurement result when the metal catalyst according to the present invention is measured by X-ray diffraction (XRD) is shown in FIG. 1. As shown in FIG. 1, no diffraction peak is observed, indicating that the metal catalyst particles in the metal catalyst to be measured are in an amorphous state.

[0058] (Method for Producing Catalyst for Ethylene Production) The method for producing a catalyst for ethylene production of the present invention is not particularly limited. For example, it includes a step of mixing a first catalyst, a second catalyst, and a third catalyst. That is, the method for producing a catalyst for ethylene production of the present invention is “(i) a metal catalyst containing a mixture of a first catalyst and a second catalyst, (ii) a third catalyst, and a method for producing a catalyst for ethylene production including a step of mixing them.”

[0059] The method for producing a catalyst for ethylene production of the present invention may include a step of mixing a first catalyst, a second catalyst, a third catalyst, and a fourth catalyst.

[0060] Specifically, for example, a solution containing a first catalyst and a second catalyst is mixed with a solution containing a third catalyst. After removing the solvent, a solid containing the remaining first to third catalysts is calcined to obtain a catalyst for ethylene production. Alternatively, a poor solvent, an acid, or an alkali is added to a solution containing a first catalyst and a second catalyst to coprecipitate and complex the first catalyst and the second catalyst, and then mixed with a third catalyst and further calcined to obtain a catalyst for ethylene production of the present invention. Alternatively, a metal catalyst containing a first catalyst and a second catalyst and a zeolite catalyst as a third catalyst are respectively prepared, and the ethylene production catalyst of the present invention can be obtained by mixing these metal catalyst and zeolite catalyst. In this case, the metal catalyst can be obtained, for example, by adding a poor solvent, or an acid or an alkali to a solution containing the first catalyst and the second catalyst to coprecipitate and complex the first catalyst and the second catalyst, and then calcining. On the other hand, for the zeolite catalyst, a commonly known production method can be used. For example, a mixed solution containing various desired components can be subjected to drying and calcination steps, or an acid can be added, and the obtained solid can be filtered, dried, and calcined to obtain the zeolite catalyst. The obtained metal catalyst and zeolite catalyst are mixed, for example, in a mortar to prepare the ethylene production catalyst.

[0061] When a fourth catalyst is also included, for example, in the same manner, a solution containing the first catalyst, the second catalyst, and the fourth catalyst and a solution containing the third catalyst are mixed. After removing the solvent, the ethylene production catalyst can be obtained by a method including a step of calcining the remaining solid containing the first to fourth catalysts. Alternatively, a solution containing the first catalyst and the second catalyst is mixed with a solution containing the fourth catalyst, and then a poor solvent, or an acid or an alkali is added to coprecipitate and complex the first catalyst, the second catalyst, and the fourth catalyst, and then mixed with the third catalyst and further calcined to obtain the ethylene production catalyst of the present invention. Alternatively, a metal catalyst containing the first catalyst, the second catalyst, and the fourth catalyst and a zeolite catalyst as the third catalyst are respectively prepared, and the ethylene production catalyst of the present invention can be obtained by mixing these metal catalyst and zeolite catalyst.

[0062] The solution containing the catalyst of the present invention is preferably an aqueous solution. The aqueous solution may contain an organic solvent miscible with water. Examples of the organic solvent miscible with water include alcohols having 1 to 4 carbon atoms. The solution may contain, for example, a ligand or the like in addition to the solvent. Mixing (composite treatment) can be carried out, for example, using a mortar, a ball mill, an automatic kneader, or the like.

[0063] The firing temperature when firing the solid is not particularly limited and may be 300°C or higher and 600°C or lower. If the firing temperature is 300°C or higher, it is easy to obtain heat stability that can withstand long-term use, and it is easy to obtain a catalyst having high catalytic activity. Also, if the firing temperature is 600°C or lower, the catalyst tends to easily form a porous structure. The firing time is not particularly limited and may be 0.1 hour or longer and 24 hours or shorter.

[0064] After the firing process is completed, post-treatment may be appropriately performed on the obtained fired product. As the post-treatment, for example, the obtained fired product may be washed and filtered. The washing can be carried out, for example, using water or a mixed solution of water and alcohol.

[0065] After filtration, it can be appropriately dried. Here, the drying may be carried out under normal pressure or under reduced pressure, but from the viewpoint of improving efficiency, it is preferably carried out under reduced pressure. Also, the temperature during drying may be, for example, 20°C or higher and 100°C or lower. The drying time during drying may be, for example, 0.1 hour or longer and 24 hours or shorter.

[0066] As a method for producing a catalyst for ethylene production, more specifically, the following method can be mentioned. For example, aqueous solutions containing iron, manganese, and magnesium are respectively prepared, and they are mixed together to prepare a mixed solution. After obtaining the mixed solution, an alkali such as sodium carbonate (Na2CO3) is added, and the first catalyst and the second catalyst are co-precipitated to obtain a precipitate. Next, after the precipitate is filtered off and recovered, the precipitate is dried and then fired to obtain a metal catalyst composed of an iron-manganese-magnesium composite powder. Here, the drying of the precipitate may be carried out under normal pressure or under reduced pressure, but it is preferably carried out under reduced pressure from the viewpoint of improving efficiency. Further, the temperature during drying may be, for example, 20°C or higher and 120°C or lower. The drying time during drying may be, for example, 0.1 hour or longer and 24 hours or shorter. The calcination carried out after drying the precipitate is not particularly limited and may be 300°C or higher and 600°C or lower. If the calcination temperature is 300°C or higher, it is easy to obtain thermal stability that can withstand long-term use, and it is easy to obtain a catalyst having high catalytic activity. Further, if the calcination temperature is 600°C or lower, the catalyst tends to easily form a porous structure. The calcination time is not particularly limited and may be 0.1 hour or longer and 24 hours or shorter. On the other hand, for the zeolite catalyst, a zeolite catalyst containing one or more zeolites selected from ITQ zeolite, ZSM-5 zeolite, SAPO zeolite, FER zeolite, and MOR zeolite is prepared by synthesizing or purchasing using a commonly known method. Then, a catalyst for ethylene production is obtained by mixing and compositing the metal catalyst and the zeolite catalyst. Here, the mixing (compositing treatment) can be carried out, for example, using a mortar, a ball mill, an automatic kneader, or the like.

[0067] (Method for producing ethylene) The production of ethylene can be carried out by bringing a raw material gas containing carbon monoxide and hydrogen into contact with the catalyst for ethylene production of the present invention. When the catalyst for ethylene production of the present invention is used, ethylene is produced using the methanol-to-olefin (MTO) reaction route in which a raw material gas containing carbon monoxide and hydrogen is converted into ethylene via methanol.

[0068] Although carbon monoxide as the raw material gas is not particularly limited, it is preferably carbon monoxide obtained by electrolytic reduction of carbon dioxide using electricity derived from renewable energy. Further, although hydrogen as the raw material gas is not particularly limited, it is preferably hydrogen obtained by electrolyzing water using electricity derived from renewable energy. Thereby, it becomes possible to further suppress the emission of greenhouse gases as a whole. In addition, by incompletely burning combustible waste such as waste plastic or biomass, carbon monoxide and hydrogen in the exhaust gas generated, or low molecular weight hydrocarbons such as methane contained in natural gas are steam reformed or dry reformed, and the resulting carbon monoxide and hydrogen can also be used as the raw material gas.

[0069] Carbon monoxide and hydrogen as the raw material gas may be supplied separately, but are usually supplied as a mixed gas thereof. The raw material gas may contain other compounds other than carbon monoxide and hydrogen. For example, inert gases such as nitrogen and argon, carbon dioxide, etc. may be further contained. From the viewpoint of productivity, a gas in which the total of carbon monoxide and hydrogen is 50% by volume or more of the whole is preferable as the raw material gas of carbon monoxide and hydrogen.

[0070] The volume ratio of hydrogen to carbon monoxide (hydrogen / carbon monoxide) in the raw material gas is preferably 0.2 or more and 5 or less, more preferably 1 or more and 4 or less, under the standard state of normal temperature and pressure. If the volume ratio of hydrogen / carbon monoxide is within the above range, the hydrogenation reaction of carbon monoxide easily proceeds sufficiently. Further, when carbon dioxide is contained in the raw material gas, the volume ratio of hydrogen to carbon dioxide (hydrogen / carbon dioxide) in the raw material gas is preferably 0.1 or more and 10 or less.

[0071] The reactor used for the contact between the raw material gas and the catalyst for ethylene production is not particularly limited, and examples thereof include reactors for general gas-phase synthesis processes such as fixed beds, jet beds, and fluidized beds, reactors for liquid-phase synthesis processes such as slurry beds, and microchannel reactors.

[0072] When performing the reaction to produce ethylene, before supplying the raw material gas to produce ethylene, a reducing gas such as hydrogen gas can be circulated to perform the reduction treatment of the catalyst. Such reduction treatment is not particularly limited, but for example, it can be performed at a temperature of 150 to 600 °C for 1 to 48 hours.

[0073] The conditions during the production of ethylene are not particularly limited, and the conditions can be set according to the type of reactor. Also, when performing the reaction to produce ethylene, the product gas containing ethylene obtained by bringing the raw material gas into contact with the ethylene production catalyst may be brought into contact with the ethylene production catalyst again. This can increase the yield of the conversion of the raw material gas to ethylene. When the product gas is brought into contact with this catalyst a plurality of times, it may be the product gas alone, or it may be a mixture of the product gas and the raw material gas.

[0074] For example, the reaction temperature during the reaction to produce ethylene is not particularly limited, and it can be a temperature of 200 to 300 °C, preferably 230 to 270 °C, and more preferably around 250 °C. Also, the pressure inside the system during the reaction is not particularly limited, but for example, it can be 0.1 to 10 MPa, preferably 0.5 to 5 MPa, more preferably 0.8 to 1.2 MPa, and particularly preferably around 1 MPa. Furthermore, the reaction time during the reaction to produce ethylene using the catalyst of the present invention is not particularly limited as long as it is at least 1 second or more, preferably 5 seconds or more.

[0075] For example, the gas hourly space velocity (GHSV) during the reaction to produce ethylene is not particularly limited, and 10 h -1 or more is preferable, and 100 h -1 or more is more preferable. If the GHSV is 10 h -1 or more, the reactor size can be made smaller. Also, the GHSV is preferably 100,000 h -1 or less, and preferably 50,000 h -1 or less. If the GHSV is 100,000 h -1If the following conditions are met, the selectivity for ethylene tends to be higher. Here, GHSV is the ratio (F / V) of the feed rate (feed amount / hour) F of the raw material gas to the volume V of the catalyst for ethylene production in the reactor. Note that the amounts of the gas and the catalyst used may be appropriately selected within a more preferable range according to the reaction conditions, the activity of the catalyst, etc., and GHSV is not limited to the above range.

[0076] Incidentally, since the methanol synthesis reaction using carbon monoxide and hydrogen as raw materials is an exothermic reaction and the conversion from methanol to ethylene is an endothermic reaction, by utilizing the heat generated in the methanol synthesis reaction for the conversion from methanol to ethylene, efficient utilization of heat can be achieved, and thus a method for producing ethylene that contributes to reducing the environmental load can be provided.

Examples

[0077] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Note that the descriptions such as "parts" and "%" in the examples mean descriptions based on mass unless otherwise specified.

[0078] (Preparation of the third catalyst) <Preparation of ITQ-2 zeolite> 4.6 g of sodium aluminum dioxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 3 g of NaOH (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in 620 g of deionized water. 38 g of hexamethyleneimine (manufactured by Flourochem) and 46 g of SiO2 (Aerosil 200, manufactured by Degussa) were added to this solution while stirring, and the mixture was held for 30 minutes. The obtained mixed solution was introduced into a Teflon (registered trademark) bottle in a stainless steel autoclave and heated at 140°C for 24 hours while stirring at 100 rpm. The obtained solid was washed several times, dried at 110°C overnight, and then calcined at 550°C in the air for 4 hours to synthesize MCM-22 (ITQ-2 precursor).

[0079] Next, 34 g of cetyltrimethylammonium bromide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 37 g of tetrapropylammonium hydroxide (40% aqueous solution, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in 100 g of deionized water. After adding 6 g of the previously synthesized MCM-22 to this solution, the mixture was stirred for 16 hours in an oil bath heated to 80°C. The resulting mixture was held in an ultrasonic generator for 60 minutes, and then 1 M hydrochloric acid was added until the pH reached 2. The resulting solid was filtered, dried at 70°C, and then calcined at 550°C in air for 8 hours to obtain ITQ-2 zeolite.

[0080] <Preparation of ZSM-5 Zeolite> ZSM-5 zeolite (manufactured by Zeolyst, model number: CBV 5524G) was prepared. Since commercially available ZSM-5 is in the ammonium form, an acid-treated one was used (denoted as H-ZSM-5 (proton form) in Table 1).

[0081] <Preparation of FER Zeolite> FER zeolite (manufactured by Zeolyst, model number: CP914C) was prepared. Since commercially available FER is in the ammonium form, an acid-treated one was used (denoted as H-FER (proton form) in Table 1).

[0082] (Preparation of Catalyst for Ethylene Production) <Preparation Example 1: Preparation of Iron-Manganese-Magnesium Composite Catalyst and Catalyst for Ethylene Production> Ferric nitrate nonahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 500 mL of water, manganese(II) nitrate hexahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 500 mL of water, and magnesium nitrate hexahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 100 mL of water to prepare iron-, manganese-, and magnesium-containing aqueous solutions, respectively. Next, the above three types of aqueous solutions were fractionally collected and mixed so that the mass ratio of iron and manganese became the mass ratio described in Table 1 to prepare a 200 g mixed solution of iron, manganese, and magnesium. Then, a 0.5 M aqueous sodium carbonate solution was added dropwise to the aqueous solution until the pH reached 7 to coprecipitate iron, manganese, and magnesium, and the precipitate was filtered off and recovered. After the precipitate was vacuum dried at 110°C for 12 hours, it was subsequently calcined at 400°C for 4 hours to obtain an iron-manganese-magnesium composite powder. Next, the iron-manganese-magnesium composite powder and the ITQ-2 zeolite of Preparation Example 1 were weighed at the mass ratios described in Table 1, and a composite treatment was performed using an agate mortar to prepare a catalyst for ethylene production described in Preparation Example 1 of Table 1.

[0083] <Preparation Examples 2 to 5> In Preparation Example 1, except that the type of the third catalyst and the mixing ratio of the first to third catalysts were changed as shown in Table 1, the catalysts for ethylene production described in Preparation Examples 2 to 5 described in Table 1 were prepared in the same manner as in Preparation Example 1. In addition, in Table 1, M represents the metal species in the second catalyst. For example, M in Preparation Example 1 represents magnesium.

[0084] <Comparative Preparation Example 1> In Preparation Example 1, except that the second catalyst was not contained, the catalyst for ethylene production described in Comparative Preparation Example 1 described in Table 1 was prepared in the same manner as in Preparation Example 1.

[0085]

Table 1

[0086] (Production of Ethylene) (Examples 1 to 5, Comparative Example 1) Using the catalysts for ethylene production described in Table 1, ethylene was synthesized from carbon monoxide and hydrogen, and the catalytic performance of the catalysts for ethylene production was evaluated by measuring the CO conversion rate and the selectivity of each organic compound.

[0087] 500 mg of the catalyst for ethylene production described in Table 1 was placed in the center of a quartz reaction tube (fixed-bed reactor) with an inner diameter of 12 mm in the reaction apparatus, and the position of the catalyst was fixed with coal wool. After replacing the reaction tube with a nitrogen atmosphere, the temperature was then raised to 350 °C while flowing hydrogen gas at 40 mL / min. Subsequently, hydrogen gas and carbon monoxide gas were supplied under the following reaction conditions (raw material gas ratio, space velocity (GHSV)), and the temperature and pressure of the feed gas in the reaction tube were controlled to the values described in the following reaction conditions. · Reaction conditions Raw material gas ratio: H2 / CO2 (volume ratio) = 2 / 1 Space velocity (GHSV): 1000 (hr -1 ) Temperature of feed gas: 250 Pressure of reaction tube: 1 MPa

[0088] The product was injected into a gas chromatograph (manufactured by Shimadzu, model number GC-2014), and then analyzed with a detector (manufactured by Shimadzu, flame ionization detector, SH-Alumina BOND / Na2SO4 30 m × 0.32 mm capillary column).

[0089] Based on the concentrations of each component by analysis, the CO conversion rate (%) and the selectivity (%) of each organic compound were calculated using the following formula, and the catalytic function of the catalyst for ethylene production was evaluated. The organic compounds to be measured were methane (CH4), ethylene (C2H4), ethane (C2H6), propylene (C3H6), propane (C3H8), butene (C4H8), butane (C4H 10 ), methanol (CH3OH), and other hydrocarbons (C5+). The selectivity (%) of each organic compound was calculated from the total volume of these organic compounds to be measured. The results are shown in Table 2.

[0090]

Equation

[0091]

Equation

[0092] (Reference Examples 1-2) For reference, the results of synthesizing an organic compound containing ethylene from carbon monoxide and hydrogen using the catalysts described in Patent Documents 1 and 2 above are shown in Table 2. Reference Example 1 describes Example 1 of Patent Document 1, and Reference Example 2 describes the examples described in Table 1 of Patent Document 2.

[0093] [Table 2]

[0094] As shown in Table 2, the catalysts of Examples 1 to 5 were capable of producing ethylene with high selectivity using carbon monoxide and hydrogen as raw materials.

Claims

1. (i)A metal catalyst comprising manganese and iron as the first catalyst and at least one or more of magnesium, calcium, strontium, barium, and sodium as the second catalyst; (ii)A zeolite catalyst containing at least one or more zeolites as the third catalyst, the ethylene production catalyst.

2. The ethylene production catalyst according to claim 1, wherein the selectivity of ethylene is 50% or more.

3. The ethylene production catalyst according to claim 1, which is a catalyst utilizing the methanol-to-olefin (MTO) reaction pathway.

4. The ethylene production catalyst according to claim 1, wherein the metal catalyst is composed of amorphous metal catalyst particles.

5. The ethylene production catalyst according to any one of claims 1 to 4, wherein the content of the second catalyst relative to the total mass of the first catalyst and the second catalyst is 1 to 50% by mass.

6. The ethylene production catalyst according to any one of claims 1 to 4, wherein the ratio of manganese to iron in the first catalyst is manganese:iron = 1:10 to 10:

1.

7. The ethylene production catalyst according to any one of claims 1 to 4, wherein the average particle diameter of the metal catalyst particles in the metal catalyst is 0.1 to 1000 μm.

8. The ethylene production catalyst according to any one of claims 1 to 4, wherein the third catalyst is one or more selected from ITQ zeolite, ZSM-5 zeolite, SAPO zeolite, FER zeolite, and MOR zeolite.

9. The ethylene production catalyst according to claim 8, wherein the ITQ zeolite is ITQ-2 zeolite.

10. The ethylene production catalyst according to any one of claims 1 to 4, wherein the ethylene production catalyst further contains one or more selected from V, Cr, Zr, Cu, Ni, Ce, Pd, Ru, Rh, Al, Si, Pt, Mo, and Ga as the fourth catalyst.

11. A method for producing the ethylene production catalyst according to any one of claims 1 to 4, comprising: (i)A metal catalyst containing a mixture of the first catalyst and the second catalyst; (ii)Mixing the third catalyst A method for producing an ethylene production catalyst, comprising a step of mixing.

12. A method for producing ethylene, comprising contacting a raw material gas containing carbon monoxide and hydrogen with the ethylene production catalyst according to any one of claims 1 to 4 to produce ethylene.

13. A method for producing ethylene according to claim 12, wherein a raw material gas containing carbon monoxide and hydrogen is brought into contact with the catalyst for ethylene production according to any one of claims 1 to 4, and ethylene is produced via methanol by a methanol-to-olefin (MTO) reaction pathway.

Images