Catalyst for producing unsaturated cyclic ether containing alkyl group, method for producing unsaturated cyclic ether containing alkyl group, and method for producing saturated cyclic ether containing alkyl group

Abstract

The present invention is a catalyst for producing an alkyl group-containing unsaturated cyclic ether, which is used for producing an alkyl group-containing unsaturated cyclic ether (2) from an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group, and which contains ruthenium and at least one of tin and platinum. The present invention is a method for producing an alkyl group-containing unsaturated cyclic ether, the method comprising a reaction step for obtaining an alkyl group-containing unsaturated cyclic ether (2) by subjecting an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group to a hydrodeoxygenation reaction in the presence of the catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalyst for producing an alkyl-containing cyclic ether, a method for producing an alkyl-containing cyclic ether, and a method for producing an alkyl-containing saturated cyclic ether. BACKGROUND

[0002] An alkyl-containing saturated cyclic ether (hereinafter, referred to as "alkyl-containing saturated cyclic ether"), particularly 2-methyltetrahydrofuran (2MeTHF), is an important organic intermediate and an excellent solvent. The alkyl-containing saturated cyclic ether has a moderate boiling point (80°C). The alkyl-containing saturated cyclic ether has a small solubility in water, is easily separated from water, and has a similar Lewis basicity to tetrahydrofuran (THF). Therefore, the alkyl-containing saturated cyclic ether can be applied to many organometallic reactions, and is widely used in industry as a new type of solvent and a raw compound for pharmaceuticals. In addition, the alkyl-containing saturated cyclic ether, particularly 2-methyltetrahydrofuran, has excellent compatibility with a hydrocarbon composition such as gasoline. The alkyl-containing saturated cyclic ether has excellent properties such as oxidation and vapor pressure. Therefore, it is used as an additive for gasoline and the like, which is a mobile vehicle fuel.

[0003] As a starting material in the industrial production of an alkyl-containing saturated cyclic ether such as 2-MeTHF, an unsaturated cyclic ether having a formyl group or a hydroxymethyl group such as furfural (hereinafter, referred to as "unsaturated cyclic ether having a formyl group or a hydroxymethyl group") corresponding to the cyclic ether is used.

[0004] Currently, in the production of 2-MeTHF using furfural as a starting material, a method via a two-stage catalytic hydrogenation reaction is used.

[0005] For example, Patent Literature 1 discloses a technology of producing 2-MeTHF by hydrogenating furfural using a continuous gas phase reaction in the presence of a copper-based catalyst to produce 2-methylfuran (2MeF) as an alkyl-containing unsaturated cyclic ether (hereinafter, referred to as "alkyl-containing unsaturated cyclic ether"), and subjecting the obtained 2MeF to a high-pressure catalytic hydrogenation reaction in the presence of a Pd / C-based catalyst.

[0006] Patent Literature 2 discloses a technology of producing 2-MeTHF by hydrogenating furfural using a continuous gas phase reaction in the presence of a Pd / C-based catalyst.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT LITERATURE

[0009] Patent Literature 1: Japanese Patent Application Laid-Open No. 2010-531838

[0010] Patent Literature 2: Japanese Patent Application Laid-Open No. 2010-531839 SUMMARY

[0011] Problem to be solved by the invention

[0012] In the technologies described in Patent Literatures 1 and 2, in the first stage reaction, the conversion rate of the raw material furfural is low, and in addition, the amount of the by-products of 1-pentanol and 1,2-pentanediol produced by the ring-opening reaction of the furan ring of the raw material furfural is large, and the yield of 2-methylfuran is insufficient.

[0013] In the technologies described in Patent Literatures 1 and 2, in the first stage reaction, the raw materials are gaseous furfural and hydrogen, and therefore, explosion-proof countermeasures and the like must be considered, and expenses for the same are required. In addition, a large high-pressure gas device is required, and there is a problem of an increase in manufacturing cost. Furthermore, a continuous gas phase reaction technology is used, and therefore, there is a problem that the processing speed of the raw material is very slow.

[0014] The present invention has been made in view of the problems of the above-described prior art.

[0015] The present invention has been made in view of the problems of the above-described prior art.

[0016] The present invention has been made in view of the problems of the above-described prior art.

[0017] The present invention has been made in view of the problems of the above-described prior art.

[0018] Solution to problem

[0019] The present inventors have found that, as a catalyst for producing 2-methylfuran and the like alkyl-containing unsaturated cyclic ether from furfural and the like formyl group- or hydroxymethyl group-containing unsaturated cyclic ether, a catalyst containing ruthenium and at least either one of tin or platinum is used, and thereby the above-described problems can be solved.

[0020] The present invention has been made in view of the problems of the above-described prior art.

[0021] [1] A catalyst for producing an alkyl-containing unsaturated cyclic ether, which is a catalyst for producing an alkyl-containing unsaturated cyclic ether (2) from an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group, and contains ruthenium and at least either one of tin or platinum.

[0022] [2] The catalyst for producing an alkyl-containing unsaturated cyclic ether according to [1], wherein the mass ratio of tin and platinum to ruthenium is 0.4 or more and 1.8 or less.

[0023] [3] The catalyst for producing an alkyl-containing unsaturated cyclic ether according to [1] or [2], wherein the catalyst is a metal carrier in which ruthenium and at least either one of tin or platinum is supported on a carrier.

[0024] [4] The catalyst for producing an alkyl-containing unsaturated cyclic ether according to [3], wherein the carrier is a carbonaceous carrier.

[0025] [5] The catalyst for producing an alkyl-containing unsaturated cyclic ether according to any one of [1] to [4], wherein the unsaturated cyclic ether (1) is furfural, and the alkyl-containing unsaturated cyclic ether (2) is 2-methylfuran.

[0026] [6] A method for producing an alkyl-containing unsaturated cyclic ether, the method comprising a reaction step of subjecting an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group to a hydrodeoxygenation reaction in the presence of a catalyst according to any one of [1] to [5], to obtain an alkyl-containing unsaturated cyclic ether (2).

[0027] [7] The method for producing an alkyl-containing unsaturated cyclic ether according to [6], wherein the hydrodeoxygenation reaction is a liquid phase reaction in the presence of an organic solvent.

[0028] [8] The method for producing an alkyl-containing unsaturated cyclic ether according to [7], wherein the organic solvent is at least one selected from the group consisting of an ether compound, an alcohol compound, and an ester compound.

[0029] [9] The method for producing an alkyl-containing unsaturated cyclic ether according to any one of [6] to [8], wherein the reaction temperature of the hydrodeoxygenation reaction is 185°C or higher.

[0030]

[10] A method for producing an alkyl-containing saturated cyclic ether, the method comprising: a hydrodeoxygenation reaction step of obtaining an alkyl-containing unsaturated cyclic ether by the method for producing an alkyl-containing unsaturated cyclic ether according to any one of [6] to [9]; and a hydrogenation reaction step of subjecting the obtained alkyl-containing unsaturated cyclic ether to a hydrogenation reaction in the presence of a noble metal catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of the elements, to obtain an alkyl-containing saturated cyclic ether.

[0031]

[11] A method for producing an alkyl-containing saturated cyclic ether, the method comprising: obtaining an alkyl-containing unsaturated cyclic ether by the method for producing an alkyl-containing unsaturated cyclic ether according to any one of [6] to [9]; and adding a noble metal catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of the elements to the obtained alkyl-containing unsaturated cyclic ether, and subjecting the same to a hydrogenation reaction, to obtain an alkyl-containing saturated cyclic ether.

[0032] Effects of the Invention

[0033] According to the present application, it is possible to provide a catalyst for producing an alkyl-containing unsaturated cyclic ether, which can perform a reaction in a liquid phase, and which can produce an alkyl-containing unsaturated cyclic ether such as 2-methylfuran from a formyl group- or hydroxymethyl group-containing unsaturated cyclic ether such as furfural with fewer by-products and at a higher yield than in the prior art.

[0034] The catalyst for producing an alkyl-containing unsaturated cyclic ether of the present application can perform a reaction in a liquid phase, and thus, as compared with the prior art method using a gaseous raw material, it does not require an excessively high-pressure gas device as described above, and can suppress manufacturing costs. Furthermore, the catalyst for producing an alkyl-containing unsaturated cyclic ether of the present application, for example, in the case of using furfural as a formyl group- or hydroxymethyl group-containing unsaturated cyclic ether, can suppress the generation of by-products such as 1-pentanol and 1,2-pentanediol due to ring-opening reaction of a furan ring, as compared with a copper-based catalyst of the prior art, and can produce an alkyl-containing unsaturated cyclic ether such as 2-methylfuran at a higher yield.

[0035] According to the present application, it is also possible to efficiently produce an alkyl-containing saturated cyclic ether such as 2-methyltetrahydrofuran from an alkyl-containing unsaturated cyclic ether such as 2-methylfuran produced by the method for producing an alkyl-containing unsaturated cyclic ether of the present application using the catalyst for producing an alkyl-containing unsaturated cyclic ether. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present application will be described in detail. The present application is not limited to the following description, and can be arbitrarily modified within the scope of the gist of the present application.

[0037] In the present specification, a numerical range represented by "~" means a range including the numerical values recited before and after "~" as lower limit values and upper limit values, unless otherwise specified. "A to B" means A or more and B or less.

[0038] In the present specification, "A or B" means "A", "B", and "A and B", unless otherwise specified. For example, "including A or B" means "including A", "including B", and "including A and B", unless otherwise specified.

[0039] In the present specification, "mass%" means the proportion of a prescribed component contained in 100 mass% of the total amount.

[0040] In the present specification, "mass%" and "weight%", "mass ppm" and "weight ppm", and "mass parts" and "weight parts" have the same meanings, respectively. In the case where only "ppm" is recited, "mass ppm" is meant.

[0041] "Arbitrary" or "arbitrarily" means that the situation described later can occur, and the situation described later can not occur. Therefore, both the case where the situation occurs and the case where the situation does not occur are included in the description.

[0042] The term "about" used in the present specification means ±20% of the value shown. For example, about 75°C includes the range of 60°C to 90°C.

[0043] All the processes recited in the present specification can be performed in any suitable order, unless otherwise specified or obviously contradicted by the context in the present specification.

[0044] [Catalyst for producing alkyl-containing unsaturated cyclic ether]

[0045] The catalyst for producing alkyl-containing unsaturated cyclic ether (hereinafter, sometimes referred to as "the present catalyst") of the present application is a catalyst for producing an alkyl-containing unsaturated cyclic ether (2). More specifically, the present catalyst is a catalyst used in a process of producing an alkyl-containing, particularly methyl-containing, unsaturated cyclic ether (2) corresponding to a formyl group- or hydroxymethyl group-containing unsaturated cyclic ether (1) from the unsaturated cyclic ether (1). The present catalyst contains ruthenium and at least either one of tin or platinum (hereinafter, sometimes simply referred to as "Ru / Sn.Pt").

[0046] In the present specification, when "at least either one of tin or platinum" is mentioned, either one of tin or platinum can be used, or both tin and platinum can be used. Among them, from the viewpoint of the yield of the target product, it is preferable to use both tin and platinum in combination with ruthenium.

[0047] The present catalyst contains Ru / Sn-Pt, and is therefore suitable as a catalyst used in the production of an unsaturated cyclic ether (2) containing an alkyl group. Specifically, the present catalyst is used for a catalyst for producing an unsaturated cyclic ether (2) containing an alkyl group corresponding to an unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, from the unsaturated cyclic ether (1), whereby the production of a by-product is less, and the unsaturated cyclic ether (2) can be produced at a high yield.

[0048] The present catalyst is generally used as a metal-supporting catalyst obtained by supporting the Ru / Sn-Pt on a support. The present catalyst is generally produced by subjecting a metal-supporting material obtained by supporting the Ru / Sn-Pt on a support to reduction treatment with a reducing gas, followed by oxidation stabilization treatment.

[0049] <Catalyst active component>

[0050] The catalyst active component in the present catalyst contains ruthenium and at least either one of tin or platinum (Ru / Sn-Pt).

[0051] The mass ratio of tin and platinum to ruthenium in the present catalyst (the mass ratio of either one of tin or platinum in the case where the present catalyst contains either one of tin or platinum; the total mass ratio of tin and platinum in the case where the present catalyst contains both of tin and platinum) is not particularly limited. From the viewpoint of less production of a by-product and high yield of the unsaturated cyclic ether (2), the mass ratio is preferably 0.4 or greater and 1.8 or less, preferably 0.45 or greater and 1.5 or less, and more preferably 0.5 or greater and 1.2 or less.

[0052] If the mass ratio is within the above range, the effects of the present application produced by using ruthenium and at least either one of tin or platinum can be effectively obtained.

[0053] <Other metal component>

[0054] The present catalyst can further contain other metals as necessary, provided that the present catalyst contains Ru / Sn-Pt as essential components, and the other metals do not impair the effects of the present application, in addition to Ru / Sn-Pt. The other metals are not particularly limited. As the other metals, at least one metal selected from the group consisting of rhodium, gold, molybdenum, tungsten, rhenium, barium, and boron, and the like, and more preferably at least one metal selected from the group consisting of rhenium and gold can be exemplified.

[0055] However, the present catalyst can obtain sufficiently high catalyst activity by using Ru / Sn-Pt.

[0056] In the case where the present catalyst contains other metal components, the lower limit of the content ratio of the other metal components, relative to 100% of the total mass of Ru / Sn-Pt and the other metal components, is not particularly limited, but from the viewpoint of producing the unsaturated cyclic ether (2) at a high yield with less by-products, it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and preferably 1.0% by mass or more. On the other hand, the upper limit of the content ratio of the other metal components is not particularly limited, but it is preferably 10% by mass or less, more preferably 5% by mass or less, and preferably 3% by mass or less.

[0057] The above upper limit and lower limit can be combined arbitrarily.

[0058] <Supporting carrier>

[0059] The present catalyst can be used as a Ru / Sn-Pt supported catalyst obtained by supporting Ru / Sn-Pt on a supporting carrier. In the case of the Ru / Sn-Pt supported catalyst, the present catalyst is excellent in operability, and the catalyst functions not only on the surface of the Ru / Sn-Pt supported catalyst but also in the inside of the pores in which Ru / Sn-Pt is supported. Therefore, it is preferable from the viewpoint of improving the conversion rate of the unsaturated cyclic ether (1) as a raw material and the selectivity of the unsaturated cyclic ether (2) as a target product.

[0060] The kind of the supporting carrier used in the present catalyst is not particularly limited. As the supporting carrier, for example, a carbonaceous supporting carrier such as activated carbon, carbon black; an inorganic porous supporting carrier of an oxide ceramic such as silicon dioxide, diatomaceous earth; silicon oxide, alumina, zirconium dioxide, titanium dioxide, hafnium dioxide; silicon carbide; gallium nitride, and the like can be used. Among them, a carbonaceous supporting carrier is preferable, and activated carbon is more preferable.

[0061] The supporting carrier can be used as it is, or can be used after being pretreated into a form suitable for supporting. For example, in the case where a carbonaceous supporting carrier is used, it can be used after being subjected to a heating treatment with nitric acid as described in Japanese Patent Application Laid-Open No. 10-71332. By this method, the dispersibility of the metal components on the supporting carrier is good, and the activity of the obtained catalyst is improved, and therefore it is preferable.

[0062] The shape of the supporting carrier used in the present catalyst is not particularly limited, and powder, particles, pellets, and the like can be exemplified. Among them, from the viewpoint of improving operability, particles and pellets are preferable.

[0063] The size of the supporting carrier used in the present catalyst is not particularly limited, but in the case where the shape is converted into a spherical shape, the average particle diameter is usually 50 μm or more and 5 mm or less, and preferably 4 mm or less.

[0064] The particle diameter of the carrier was measured by the sieve test method described in JIS Standard JIS Z8815 (1994).

[0065] By setting the average particle diameter to the above range, a catalyst having high activity per unit weight and further easy to handle is obtained.

[0066] In the case where the reaction using the present catalyst is a complete mixing type reaction, the particle diameter of the carrier is usually 50 μm or more, preferably 100 μm or more, and usually 3 mm or less, preferably 2 mm or less. The smaller the particle diameter of the carrier, the higher the activity per unit mass of the obtained catalyst, and this is preferable. When the particle diameter of the carrier is too small compared with the lower limit value, separation of the reaction liquid from the catalyst sometimes becomes difficult. In the case where the shape of the carrier is not spherical, the particle diameter of the carrier is set to the diameter of a spherical particle having the same volume as the carrier.

[0067] In the case where the reaction using the present catalyst is a fixed bed reaction, the particle diameter of the carrier is usually 0.5 mm or more and 5 mm or less, preferably 4 mm or less, and more preferably 3 mm or less. In the case where the particle diameter is too small compared with the lower limit value, the progress of the reaction sometimes becomes difficult due to the pressure difference. When the particle diameter is too large compared with the upper limit value, the reaction activity sometimes decreases.

[0068] <Ru / Sn-Pt loading amount>

[0069] The loading amount of Ru / Sn-Pt on the carrier in the present catalyst is not particularly limited. For example, the lower limit of the loading amount of ruthenium is usually 1 part by mass or more, and preferably 3 parts by mass or more, relative to 100 parts by mass of the total mass of the present catalyst. On the other hand, the upper limit of the loading amount of Ru / Sn-Pt is usually 10 parts by mass or less, and preferably 8 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0070] The above upper and lower limits can be combined arbitrarily. For example, the loading amount of Ru / Sn-Pt on the carrier in the present catalyst is usually 1 part by mass or more and 10 parts by mass or less, and preferably 3 parts by mass or more and 8 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0071] The lower limit of the loading amount of either or both of tin and platinum on the carrier in the present catalyst is usually 1 part by mass or more, and preferably 2 parts by mass or more, relative to 100 parts by mass of the total mass of the present catalyst. On the other hand, the upper limit of the loading amount of either or both of tin and platinum is usually 15 parts by mass or less, and preferably 10 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0072] The upper limit and the lower limit described above can be combined arbitrarily. For example, the supported amount of either or both of tin and platinum in the present catalyst on the support is usually 1 part by mass or more and 15 parts by mass or less, preferably 2 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0073] The supported amount of the other metal used as needed is not particularly limited. The supported amount of the other metal can be usually 7 parts by mass or less, preferably 5 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst, within a range not impairing the effects of the present application.

[0074] The lower limit of the supported amount of the total of Ru / Sn·Pt and the other metal is not particularly limited, but is usually 5 parts by mass or more, preferably 8 parts by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the total mass of the present catalyst. On the other hand, the upper limit of the supported amount of the total of Ru / Sn·Pt and the other metal is not particularly limited, but is usually 40 parts by mass or less, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0075] The upper limit and the lower limit described above can be combined arbitrarily. For example, the supported amount of the total of Ru / Sn·Pt and the other metal is usually 5 parts by mass or more and 40 parts by mass or less, preferably 8 parts by mass or more and 30 parts by mass or less, more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total mass of the present catalyst.

[0076] The supported amount of the metal is a value obtained by converting the total of the supported metals into metal atoms. The supported amount of the metal can be determined, for example, by dissolving the metal component from the metal-supported catalyst using an acid, analyzing the concentration in the solution using atomic absorption spectrometry, inductively coupled plasma (ICP) emission spectrometry, or the like, or by pulverizing the metal-supported catalyst to 50 μm or less and then determining by fluorescence X-ray (XRF) analysis in the solid state.

[0077] <Method for producing the present catalyst>

[0078] The method for producing the present catalyst is not particularly limited. The present catalyst can be produced, for example, by appropriately optimizing the method for producing the catalyst described in paragraphs 0033 to 0079 of Japanese Patent Application Publication No. 2020-168628, according to known techniques, by those skilled in the art.

[0079] [Unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group]

[0080] The unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, which is an application of the present catalyst, is not particularly limited, but an unsaturated cyclic ether having a five-membered ring or a six-membered ring such as furan, pyran, dihydropyran, and the like, which contains a formyl group or a hydroxymethyl group, can be exemplified. Among them, from the viewpoint of the use of the unsaturated cyclic ether (2) containing an alkyl group, which is produced by the present catalyst, easiness of obtaining, and the like, furfural, dihydropyran, and the like are preferable, and furfural is most preferable.

[0081] [Unsaturated cyclic ether containing an alkyl group (2)]

[0082] The unsaturated cyclic ether (2) containing an alkyl group, which is produced from the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group by the present catalyst, is obtained by converting a formyl group or a hydroxymethyl group into a methyl group through a hydrodeoxygenation reaction of the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group. Specifically, 2-methylfuran, 2-methyl-2,3-dihydro-4H-pyran, and the like can be exemplified. Based on the same reason, 2-methylfuran is most preferable.

[0083] The present catalyst is suitable as a catalyst for producing 2-methylfuran, which is an unsaturated cyclic ether (2) containing an alkyl group, from furfural, which is an unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group.

[0084] [Method for producing unsaturated cyclic ether containing an alkyl group]

[0085] The method for producing an unsaturated cyclic ether containing an alkyl group of the present application is a method for producing an unsaturated cyclic ether (2) containing an alkyl group, which includes a reaction step of subjecting an unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group to a hydrodeoxygenation reaction in the presence of the present catalyst to obtain an unsaturated cyclic ether (2) containing an alkyl group, which corresponds to the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group.

[0086] The method for producing an unsaturated cyclic ether (2) containing an alkyl group based on the present catalyst is not particularly limited as long as it is performed in the presence of the present catalyst. The method for producing an unsaturated cyclic ether (2) containing an alkyl group based on the present catalyst is preferably a heterogeneous reaction in which a hydrodeoxygenation reaction is performed by continuously or batchwise contacting an unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, the present catalyst, and hydrogen.

[0087] More specifically, the hydrodeoxygenation reaction can be a reaction in a gas-liquid-solid three-phase system, which is carried out by bringing a liquid unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) or a solution containing the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) into contact with hydrogen (hydrogen gas), or can be a reaction in a gas-solid two-phase system, which is carried out by bringing a gaseous (vaporized) unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) into contact with hydrogen. In particular, from the viewpoint of suppressing the generation of by-products caused by the cleavage of a carbon-carbon bond in the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) or the like, it is preferable to carry out the hydrodeoxygenation reaction in a gas-liquid-solid three-phase system which can be carried out at a relatively low temperature. In particular, it is preferable to use a liquid-phase reaction in which a solution containing the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) is brought into contact with hydrogen in the presence of the present catalyst.

[0088] The solvent used in the liquid-phase reaction can be appropriately selected depending on the kind of the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) and is not particularly limited. When water is used as the solvent, polymerization, rearrangement reaction easily proceeds, and the hydrodeoxygenation reaction does not proceed. Therefore, it is preferable to use an organic solvent.

[0089] As the organic solvent used in the hydrodeoxygenation reaction in the present application, there is no particular limitation, but for example, the following organic solvents can be listed.

[0090] dioxane, 2-methyltetrahydrofuran, and the like; ethyl acetate, butyl acetate, and the like; methanol, ethanol, isopropanol, n-butanol, 2-butanol, and the like; hexane, heptane, octane, and the like; cyclohexane and the like; benzene, toluene, xylene, ethylbenzene, and the like; chloroform, dichloromethane, 1,2-dichloroethane, and the like; acetonitrile, propionitrile, benzonitrile, and the like; and the like.

[0091] These organic solvents can be used alone or in combination of two or more.

[0092] Among these organic solvents, from the viewpoint of easiness of separation from the product, economy, and harmfulness, ether-based compounds, alcohol-based compounds, ester-based compounds are preferable, and ether-based compounds, alcohol-based compounds are particularly preferable.

[0093] The amount of use of the organic solvent is not particularly limited. The amount of use of the organic solvent can be appropriately selected from the range in which the concentration of the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) is 5 to 80% by mass, particularly 20 to 60% by mass, for example, from the case where the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) is dissolved before the hydrodeoxygenation reaction.

[0094] The lower limit of the amount of the present catalyst used in the hydrodeoxygenation reaction is not particularly limited, but from the viewpoint of the reaction rate, it is preferably set to a range of 2% by mass or more, more preferably 5% by mass or more, and further preferably 8% by mass or more, with respect to the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1), in terms of the amount of Ru / Sn-Pt in metal.

[0095] The upper and lower limits described above can be combined arbitrarily. For example, the amount of the present catalyst used in the hydrodeoxygenation reaction is preferably set to a range of 2 to 25% by mass, more preferably 5 to 20% by mass, and further preferably 8 to 18% by mass, with respect to the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1), in terms of the amount of Ru / Sn-Pt in metal.

[0096] The ratio of hydrogen to the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1) supplied to the hydrodeoxygenation reaction is not particularly limited and can be appropriately set depending on the reaction form employed or the like.

[0097] In the hydrodeoxygenation reaction, other components besides the unsaturated cyclic ether containing a formyl group or a hydroxymethyl group (1), the present catalyst, and hydrogen can also coexist within a range that does not hinder the effects of the present application.

[0098] The lower limit of the reaction temperature in the hydrodeoxygenation reaction is not particularly limited, but when the reaction temperature is too low, the hydrodeoxygenation reaction cannot proceed smoothly. Therefore, it is preferably 185°C or higher, more preferably 190°C or higher, and further preferably 200°C or higher. On the other hand, the upper limit of the reaction temperature is not particularly limited, but when it is too high, side reactions are likely to occur. Therefore, it is preferably 240°C or lower, more preferably 230°C or lower, and further preferably 220°C or lower.

[0099] The upper and lower limits described above can be combined arbitrarily. For example, the reaction temperature in the hydrodeoxygenation reaction is not particularly limited, but it is preferably 185°C or higher and 240°C or lower, more preferably 190°C or higher and 230°C or lower, and further preferably 200°C or higher and 220°C or lower.

[0100] The reaction temperature can be controlled to be fixed (substantially fixed) at all times in the hydrodeoxygenation reaction, or it can be controlled to change periodically or continuously.

[0101] The reaction time in the hydrodeoxygenation reaction is not particularly limited and can be appropriately set depending on the reaction form employed or the like.

[0102] The lower limit of the reaction pressure (hydrogen pressure) in the hydrodeoxygenation reaction is not particularly limited, but is usually 0.1 MPa or higher, more preferably 1.0 MPa or higher. On the other hand, the upper limit of the reaction pressure is not particularly limited, but is usually 20 MPa or lower, more preferably 10 MPa or lower.

[0103] The above lower limit and upper limit can be combined arbitrarily. For example, the reaction pressure in the hydrodeoxygenation reaction is not particularly limited, but is usually 0.1 to 20 MPa, more preferably 1 to 10 MPa.

[0104] The reaction pressure can be controlled to be fixed (substantially fixed) always in the hydrodeoxygenation reaction, or can be controlled to be changed periodically or continuously.

[0105] The hydrodeoxygenation reaction can be performed by any of batch, semi-batch, continuous (continuous flow) and the like.

[0106] In the case where the amount of the unsaturated cyclic ether (2) containing an alkyl group, which is obtained from a prescribed amount of the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, is intended to be increased, a process in which the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, which is unreacted after the reduction reaction is performed, is separated and recovered and recycled can be employed.

[0107] In the hydrodeoxygenation reaction, a publicly known or conventional reactor can be used as the reactor. For example, a batch reactor, a fluidized bed reactor, a fixed bed reactor and the like can be used.

[0108] The production method of the unsaturated cyclic ether containing an alkyl group according to the present application can arbitrarily include other processes as needed in addition to the hydrodeoxygenation reaction. As the other processes, for example, a process of preparing / purifying a solution of the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group as a raw material; a process of separating a reaction product (for example, a mixture containing the unsaturated cyclic ether (2) containing an alkyl group, hydrogen and the unsaturated cyclic ether (1) containing a formyl group or a hydroxymethyl group, a by-product and the like) discharged (flowed out) from the reactor to purify a target product; a process of performing a regeneration treatment of a catalyst and the like can be exemplified.

[0109] These processes can be performed by a production line different from the hydrodeoxygenation reaction, or can be performed as a series of processes (on-line).

[0110] The unsaturated cyclic ether (2) containing an alkyl group, which is obtained by the production method of the unsaturated cyclic ether containing an alkyl group according to the present application, can be purified by a publicly known or conventional method (for example, distillation, adsorption, ion exchange, crystallization, extraction and the like).

[0111] The target product can be recovered, for example, by the following method.

[0112] The reaction product obtained in the hydrodeoxygenation reaction process is condensed by a publicly known technique, preferably by cooling in a heat exchanger. The condensation causes phase separation. The lower phase obtained by the phase separation consists of more than 90% of water. The upper phase obtained by the phase separation contains the target alkyl group-containing unsaturated cyclic ether (2) and a small amount of by-products, which can be efficiently separated and removed by distillation in a subsequent process or the like. The alkyl group-containing unsaturated cyclic ether (2) can be obtained in a very good yield and purity by the method of the present application.

[0113] The phase separation can also be performed at normal temperature (about 25 degrees), but the lower the temperature, the lower the solubility in water in terms of the alkyl group-containing unsaturated cyclic ether (2), and thus the phase separation is preferably performed at 20°C or lower, for example, at 5 to 15°C.

[0114] In terms of the upper phase containing the target product, i.e., the alkyl group-containing unsaturated cyclic ether (2), obtained by the phase separation, distillation can be performed, for example, by using a packed column having metal rings or the like as packing bodies, to recover the alkyl group-containing unsaturated cyclic ether (2) in a high purity.

[0115] However, the distillation process is not essential. For example, in the case where the alkyl group-containing unsaturated cyclic ether (2) obtained by the production method of the alkyl group-containing saturated cyclic ether of the present application described later is subjected to a hydrogenation reaction to produce an alkyl group-containing saturated cyclic ether, the reaction product liquid obtained in the hydrodeoxygenation reaction can be directly supplied to the subsequent hydrogenation reaction process.

[0116] [Production method of alkyl group-containing saturated cyclic ether]

[0117] The first embodiment of the production method of the alkyl group-containing saturated cyclic ether of the present application includes a process of obtaining the alkyl group-containing unsaturated cyclic ether (2) by the production method of the alkyl group-containing unsaturated cyclic ether of the present application, and a hydrogenation reaction process of subjecting the obtained alkyl group-containing unsaturated cyclic ether (2) to a hydrogenation reaction in the presence of a noble metal catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of elements, to obtain an alkyl group-containing saturated cyclic ether (hereinafter, sometimes referred to as "alkyl group-containing saturated cyclic ether (3)") corresponding to the alkyl group-containing unsaturated cyclic ether (2).

[0118] The second embodiment of the production method of the alkyl group-containing saturated cyclic ether of the present application includes obtaining an alkyl group-containing unsaturated cyclic ether by the production method of the alkyl group-containing unsaturated cyclic ether of the present application, and adding a catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of elements to the obtained alkyl group-containing unsaturated cyclic ether, to perform a hydrogenation reaction, to obtain an alkyl group-containing saturated cyclic ether (3).

[0119] <Precious metal catalyst>

[0120] In the first and second embodiments of the method for producing an alkyl-containing saturated cyclic ether according to the present application, as the precious metal catalyst containing at least one selected from the group consisting of Group 8 and Group 10 precious metals of the long-form periodic table of the elements, rhodium, ruthenium, platinum, palladium, iridium, osmium and the like are preferably exemplified. Among these, ruthenium, rhodium and palladium are particularly preferable in terms of reactivity and selectivity.

[0121] As the precious metal catalyst, specifically, 0-valent precious metal or various inorganic compounds such as nitrate, sulfate, acetate, chloride, bromide, oxide, hydroxide and the like of the precious metal, carrier-supported catalyst in which the precious metal is supported on a carrier, various organic compounds such as acetylacetone compound and the like, amine complex, phosphine complex, carbonyl compound and the like, and various metal compounds can be exemplified.

[0122] These can be used individually or in combination of two or more.

[0123] The loading amount of the metal component of the carrier-supported catalyst is not particularly limited, but is usually 0.1 to 10% by mass, and preferably 0.5 to 5% by mass, in terms of the metal component, relative to the total mass of the catalyst. When the loading amount is less than 0.1% by mass, the activity per unit amount of the catalyst decreases, and a large amount of the catalyst needs to be used, which is not advantageous in terms of equipment and economy. Even when the loading amount exceeds 10% by mass, it is difficult to obtain an increase in the reaction rate corresponding to the amount of the metal supported.

[0124] As the carrier-supported catalyst, conventionally known or commercially available catalysts can be used.

[0125] As the carrier used in the carrier-supported catalyst, diatomaceous earth, pumice, carbon (activated carbon, graphite, carbon black and the like), silica gel, alumina, silica / alumina, magnesium oxide, zirconium oxide, titanium oxide, zeolite, calcium carbonate, barium sulfate and the like can be exemplified. These carriers can be used individually or in combination of two or more. Among these, carbon or alumina is particularly preferable in terms of reactivity and selectivity.

[0126] As the precious metal-supported carrier catalyst, specifically, Ru-carbon catalyst, Rh-carbon catalyst, Pd-carbon catalyst, Ru-alumina catalyst, Rh-alumina catalyst, Pd-alumina catalyst can be exemplified. Among these, Pd-carbon catalyst and Pd-alumina catalyst are particularly preferable.

[0127] The water content of the precious metal-supported carrier catalyst is not particularly limited, and both dried and hydrous products can be used.

[0128] The form of the noble metal catalyst in the present application is not particularly limited, and a powder, a shaped catalyst, or the like is appropriately selected according to the selected reaction mode and used.

[0129] The powder catalyst is generally used for hydrogenation reactions in a batch or continuous liquid phase suspension bed.

[0130] The shaped catalyst is used for hydrogenation reactions in a fixed bed flow-through mode. As the shaped catalyst, an appropriate one is selected according to the size of the reactor used. The shaped catalyst is generally preferably in the form of a cylinder having a diameter of 2 to 6 mm and a height of 2 to 8 mm.

[0131] As the method for producing the carrier-supported catalyst, a method known in the art such as an impregnation method or a co-precipitation method can be used. As the method for activating these carrier-supported catalysts, there is no particular limitation, but reduction and activation treatment are generally performed before use.

[0132] As for the amount of the noble metal catalyst used in the hydrogenation reaction, from the viewpoint of reaction speed and economy, it is preferably in the range of 0.0005 to 5 parts by mass, preferably 0.005 to 3 parts by mass, and further preferably 0.01 to 2 parts by mass, based on the metal component, relative to 100 parts by mass of the total mass of the alkyl group-containing unsaturated cyclic ether (2).

[0133] <Reaction Solvent>

[0134] The hydrogenation reaction of the present application can be performed in the presence or absence of a solvent. As the solvent that can be used in the case of performing in the presence of a solvent, there is no particular limitation as long as it does not adversely affect the hydrogenation reaction.

[0135] As the reaction solvent, for example, the following can be mentioned: water; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 1-pentanol, 2-pentanol, 3-pentanol, hexanol, heptanol, octanol, propylene glycol, ethylene glycol, diethylene glycol, tetraethylene glycol, glycerol, 1,3-propanediol, cyclohexanol, and the like known alcohol-based solvents; diethyl ether, diisopropyl ether, dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, and the like known ether-based solvents; n-pentane, n-hexane, n-heptane, n-octane, 2-ethylhexane, n-nonane, n-decane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, decalin, and the like known aliphatic hydrocarbon-based solvents; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, methyl propionate, ethyl propionate, and the like known ester-based solvents; ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and the like known carbonate-based solvents; γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, and the like lactone-based solvents; N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like amide-based solvents, and the like.

[0136] These solvents can be used alone or in combination of two or more.

[0137] The amount of the reaction solvent used can be arbitrarily selected depending on the reaction conditions, reaction mode, and the like.

[0138] <Reaction conditions>

[0139] The hydrogen partial pressure in the hydrogenation reaction of the present application is not particularly limited as long as it is a condition under which the hydrogenation reaction is completed. As a condition for obtaining a practical reaction rate, the hydrogen partial pressure of the reaction system is usually in the range of 0.1 to 30 MPa, and preferably in the range of 0.1 to 10 MPa. When the hydrogen partial pressure is lower than 0.1 MPa, the reaction requires a longer time than necessary. When the hydrogen partial pressure exceeds 30 MPa, the reaction rate increases, but even if the pressure is excessively high, it is not considered to be significantly meaningful, and sometimes it is economically disadvantageous.

[0140] The reaction temperature is not particularly limited as long as it is a condition under which the hydrogenation reaction is completed. As a condition for obtaining a practical reaction rate, the reaction temperature is usually in the range of 20 to 200°C, and preferably in the range of 40 to 180°C. In the case of lower than this temperature range, a sufficient reaction rate cannot be obtained. In the case of higher than this temperature range, side reactions and decomposition reactions occur, and thus a tendency of a decrease in yield can be seen.

[0141] The reaction time varies depending on the amount of the catalyst and various conditions. It is preferable that the conditions and the like are selected so as to satisfy: the reaction time is usually about 0.5 to 50 hours, and from an industrial viewpoint, it is 1 to 20 hours.

[0142] The reaction mode of the hydrogenation reaction of the present application is not particularly limited. As the reaction mode, a method based on a liquid-phase suspension bed in which a noble metal catalyst is dispersed in a reaction liquid, or a method based on a fixed bed flow-through mode in which a noble metal catalyst is fixed in a reactor and a reaction liquid is allowed to act thereon, or the like can be employed.

[0143] After the reaction is completed, in the case where the catalyst needs to be removed, the catalyst is removed by a conventionally known method such as filtration, centrifugal separation, or the like, and the alkyl group-containing saturated cyclic ether (3) can be obtained. If necessary, by performing purification by distillation or the like, an alkyl group-containing saturated cyclic ether (3) having high purity can be obtained.

[0144] From a reaction product liquid containing the alkyl group-containing saturated cyclic ether (3) obtained by the hydrogenation reaction of the present application, by performing phase separation, distillation operation in the same manner as in the reaction product liquid containing the aforementioned alkyl group-containing unsaturated cyclic ether (2), the target alkyl group-containing saturated cyclic ether (3) can be recovered.

[0145] The alkyl group-containing saturated cyclic ether (3) produced by the production method of the alkyl group-containing saturated cyclic ether of the present application is a saturated cyclic ether in which a hydrogen atom is added to the unsaturated cyclic ether double bond of the alkyl group-containing unsaturated cyclic ether (2) produced by the production method of the alkyl group-containing unsaturated cyclic ether of the present application. For the same reason as described above, as the produced alkyl group-containing saturated cyclic ether (3), 2-methyltetrahydrofuran is preferably exemplified.

[0146] The production method of the alkyl group-containing saturated cyclic ether of the present application is extremely useful in industry as a method in which 2-methyltetrahydrofuran is produced by a hydrodeoxygenation reaction using the present catalyst, starting from furfural, and 2-methyltetrahydrofuran is produced by a hydrogenation reaction of 2-methylfuran.

[0147] Examples

[0148] Hereinafter, the present application will be described more specifically by citing examples and comparative examples. The present application is not limited by the following examples as long as the gist of the present application is not exceeded.

[0149] The following examples are merely examples and are not intended to limit any of the embodiments described in the specification. The following examples do not limit the present application in any way.

[0150] The values of the various production conditions and evaluation results in the following examples have the meaning of preferred values as upper limits or lower limits in the embodiments of the present application, and the preferred range can be a range defined by the combination of the values of the upper limit or lower limit described above and the values of the following examples or the values between the examples.

[0151] [Raw materials]

[0152] The abbreviations of the raw materials used in the examples and comparative examples are described below.

[0153] Copper-zinc-alumina catalyst (trade name: N2B3, activated carbon-supported product, manufactured by Nikka Chemical Mfg. Co., Ltd.).

[0154] Copper-chromium catalyst (trade name: N-203SD, activated carbon-supported product, manufactured by Nikka Chemical Mfg. Co., Ltd.).

[0155] Copper-iron-alumina catalyst (trade name: N2A3, activated carbon-supported product, manufactured by Nikka Chemical Mfg. Co., Ltd.).

[0156] 5% Ru carbon catalyst (trade name: B-Type, manufactured by N.E. CHEMCAT CORPORATION).

[0157] 5% Pd carbon catalyst (trade name: STD-Type, manufactured by N.E. CHEMCAT CORPORATION).

[0158] 5% Pt carbon catalyst (manufactured by N.E. CHEMCAT CORPORATION).

[0159] [Assessment method]

[0160] The assessment method of each physical property value is described below.

[0161] [Conversion rate of furfural and yield of 2-methylfuran and by-products]

[0162] The conversion rate of furfural and the yield of 2-methylfuran and by-products of the reaction liquid obtained in the examples and comparative examples were determined according to the following procedure.

[0163] For the reaction liquid obtained in the examples and comparative examples, the composition analysis of furfural (FA) as a raw material, 2-methylfuran (2MeF) and 2-methyltetrahydrofuran (2MeTHF) as target products, 1-pentanol (1POL), furfuryl alcohol (FOL), 2-methylhydroxytetrahydrofuran (THFOL), 1,2-pentanediol (12PDOL), 1,4-pentanediol (14PDOL) as by-products, and other impurities was performed using a gas chromatograph (GC) measuring device under the following measurement conditions. As the other impurities, the decomposition or deterioration products of FA, the polymer of FOL, and the like can be listed.

[0164] Diethylene glycol dimethyl ether 0.7 g as an internal standard substance was added to the reaction liquid, solvent was added so as to be 10 g, 0.2 g thereof was taken, and further diluted with solvent to 10 times to prepare a sample for GC analysis.

[0165] [GC measurement conditions]

[0166] GC device: GC-2014 (device name, manufactured by Shimadzu Corporation).

[0167] Detector: hydrogen flame ionization detector (FID).

[0168] Carrier gas: helium (flow rate 1 ml / min).

[0169] Chromatographic column: capillary chromatographic column DB-1 (manufactured by Agilent Technologies, size: length 60 m x inner diameter 0.25 mm, film thickness 0.25 μm).

[0170] Chromatographic column temperature: 50°C (holding time 5 minutes) -> temperature increase at 5°C / min -> 150°C (no holding time) -> temperature increase at 15°C / min -> 300°C (no holding time).

[0171] Injection port temperature: 250°C.

[0172] Detector temperature: 300°C.

[0173] Sample amount: 1 μL (split ratio: 1 / 20).

[0174] Quantitative method: internal standard method using diglyme as an internal standard substance.

[0175] [Reference Example 1: Production of Catalyst A]

[0176] As the carrier, 1 mm cylindrical activated carbon (trade name: Norit R1 EXTRA, manufactured by NORIT Corporation) was used, and the production of Catalyst A was performed by the method according to Example 4 of Japanese Patent Application Laid-Open No. 2001-9277.

[0177] An aqueous solution containing ruthenium chloride hydrate and chloroplatinic acid (IV) hexahydrate, tin (II) chloride dihydrate, metal chlorides was used to support ruthenium, platinum, and tin in the metal chlorides on the activated carbon, and a metal support (hereinafter referred to as "metal support 1") was prepared. In the production of the metal support 1, the amount of the aqueous solution of the metal chlorides when impregnated in the activated carbon was set to be the same as the pore volume of the activated carbon.

[0178] An aqueous ammonium bicarbonate solution (pH = 8.5) in which the concentration of ammonium bicarbonate with respect to the chlorine of the metal chloride was adjusted to 12 mass% in terms of 2 times the molar amount was prepared, and the metal support 1 was added thereto, and the treatment was performed by the method according to Example 1 and Example 4 of Japanese Patent Application Publication No. 2001-9277. The treated metal support 1 (about 2 g) was dried under an argon stream (5 L / h) at 150°C for 2 hours, and then reduced under a hydrogen stream (5 L / h) at 500°C for 2 hours. Thereafter, oxidation stabilization was performed under a nitrogen stream (2 L / h) having an oxygen concentration of 5.0% to obtain a metal oxide, which was used as Catalyst A.

[0179] In the obtained Catalyst A, the amounts of the metal elements to be fed were set so that, when the total amount of the feed was supported, hydrogen reduction, and oxidation stabilization were performed, with respect to 100 parts by mass of the total mass of the carbonaceous carrier, Ru was 5.5 parts by mass, Pt was 2.4 parts by mass, and Sn was 6.4 parts by mass (the mass ratio of tin and platinum with respect to ruthenium was 1.6).

[0180] [Reference Example 2: Production of Catalyst B]

[0181] A metal oxide was produced by the method according to Reference Example 1, except that hexachloroplatinic acid (IV) hexahydrate was not used, which was used as Catalyst B.

[0182] In the obtained Catalyst B, the amounts of the metal elements to be fed were set so that, when the total amount of the feed was supported, hydrogen reduction, and oxidation stabilization were performed, with respect to 100 parts by mass of the total mass of the carbonaceous carrier, Ru was 5.0 parts by mass, and Pt was 4.0 parts by mass (the mass ratio of platinum with respect to ruthenium was 0.8).

[0183] [Reference Example 3: Production of Catalyst C]

[0184] A metal oxide was produced by the method according to Reference Example 1, except that silica gel (trade name: CARiACT Q-15, manufactured by Fuji Silysia Chemical Ltd.) was used as the carrier, and the treatment with ammonium bicarbonate was not performed, which was used as Catalyst C.

[0185] In the obtained Catalyst C, the amounts of the metal elements to be fed were set so that, when the total amount of the feed was supported, hydrogen reduction, and oxidation stabilization were performed, with respect to 100 parts by mass of the total mass of the silica gel carrier, Ru was 5.5 parts by mass, Pt was 2.4 parts by mass, and Sn was 6.4 parts by mass (the mass ratio of tin and platinum with respect to ruthenium was 1.6).

[0186] [Reference Example 4: Production of Catalyst D]

[0187] A metal support was prepared by the method according to Reference Example 3, except that alumina (trade name: JRC-ALO-5A, Catalyst Society Reference Catalyst) was used as the carrier, and then the metal support was subjected to hydrogen reduction and oxidation stabilization to obtain a metal oxide, which was used as Catalyst D.

[0188] In the obtained Catalyst D, the amounts of the metal elements to be fed were set such that, when the total amount to be fed was supported, subjected to hydrogen reduction, and subjected to oxidation stabilization, with respect to 100 parts by mass of the total mass of the alumina carrier, Ru was 5.5 parts by mass, Pt was 2.4 parts by mass, and Sn was 6.4 parts by mass (the mass ratio of tin and platinum with respect to ruthenium was 1.6).

[0189] [Example 1: Production of 2MeF]

[0190] Into a 70 mL rotary agitator autoclave (AC), 1.00 g of FA, 4.00 g of dioxane as a solvent, and 0.6 g of Catalyst A were charged. Then, the operation of replacing the inside of the AC with nitrogen (pressure: 1 MPa) was repeated three times. Then, the operation of replacing the inside of the AC with hydrogen (pressure: 3 MPa) was repeated three times. Then, with the hydrogen pressure in the AC set to 3 MPa, the temperature in the AC was raised to 200°C, and then the hydrodeoxygenation reaction of FA was performed for 2 hours. After the reaction was completed, the temperature in the AC was cooled to room temperature (25°C), and nitrogen replacement was performed in the AC. In the case where nitrogen replacement was performed in the AC, the reaction liquid was discharged from the bottom of the AC. The obtained reaction liquid was subjected to gas chromatographic analysis, and it was confirmed that 2MeF was produced. The analysis results are shown in Table 1.

[0191] [Examples 2 and Comparative Examples 1 to 6: Type of Catalyst]

[0192] 2MeF was produced by the same method as in Example 1, except that the type of catalyst and the reaction temperature were changed as described in Table 1 in Example 1. The analysis results are shown in Table 1.

[0193] [Table 1]

[0194]

[0195]

[0196]

[0197] As shown in Table 1, in Examples 1 and 2, 2MeF was produced in a high yield with a small amount of by-products.

[0198] On the other hand, in Comparative Examples 1 to 6, the catalyst did not contain ruthenium and tin and / or platinum, and therefore the yield of 2MeF was low and the amount of by-products was large.

[0199] [Reference Comparative Examples 7 to 8: Type of catalyst and support]

[0200] Except that the type of catalyst and support was changed as described in Table 2 in Example 1, 2MeF was produced by the same method as in Example 1. The results of the analysis are shown in Table 2. The results of Example 1 are also described in Table 2.

[0201] [Table 2]

[0202] [Table 2]

[0203]

[0204] As shown in Table 2, in Reference Comparative Example 7, the support was not a carbonaceous support but silica, and therefore the yield of 2MeF was low. The generation of alcohol as a by-product was small, and the yield of FOL as an intermediate was high.

[0205] On the other hand, in Reference Comparative Example 8, the support was not a carbonaceous support but alumina (AI2O3), and therefore the yield of 2MeF was low. It is presumed that this is because alumina has an acid site, and therefore a side reaction such as polymerization of the raw material and the intermediate was performed.

[0206] [Examples 3 to 5 and Reference Comparative Example 9: Type of solvent]

[0207] Except that the solvent was changed to the solvent described in Table 3 in Example 1, 2MeF was produced by the same method as in Example 1. The results of the analysis are shown in Table 3. The results of Example 1 are also described in Table 3.

[0208] [Table 3]

[0209] [Table 3]

[0210]

[0211] As shown in Table 3, in Examples 1, 3 to 5, by-products were small, and 2MeF was produced at a high yield.

[0212] On the other hand, in Reference Comparative Example 9, water was used as the solvent, and therefore the hydrodeoxygenation reaction of FA was not performed, and 2MeF was not obtained.

[0213] [Examples 6 to 7 and Reference Comparative Example 10: Reaction temperature]

[0214] Except that the reaction temperature was changed as described in Table 4 in Example 1, 2MeF was produced by the same method as in Example 1. The results of the analysis are shown in Table 4. The results of Example 1 are also described in Table 4.

[0215] [Table 4]

[0216] [Table 4]

[0217]

[0218] As shown in Table 4, in Examples 1, 6 to 7, by-products were less, and 2MeF was produced at a high yield.

[0219] On the other hand, in Reference Comparative Example 10, the reaction temperature was low, and thus the FA conversion rate and the yield of 2MeF were low, and by-products (FOL) were generated in large amounts.

[0220] [Example 9: Production of 2MeTHF]

[0221] After obtaining the reaction liquid under the same conditions as in Example 1, 0.1 g of 5% Pd-carbon catalyst was charged into the AC. Subsequently, the operation of replacing the inside of the AC with nitrogen (at a pressure of 1 MPa) was repeated three times. Subsequently, the operation of replacing the inside of the AC with hydrogen (at a pressure of 3 MPa) was repeated three times. Subsequently, under the condition that the hydrogen pressure in the AC was set to 3 MPa, the temperature in the AC was raised to 180°C, and then the hydrogenation reaction of 2MeF in the reaction liquid was performed for 2 hours. After the completion of the reaction, the temperature in the AC was cooled to room temperature (25°C), and nitrogen replacement was performed in the AC. In the case where nitrogen replacement was performed in the AC, the reaction liquid was discharged from the bottom of the AC. Gas chromatographic analysis of the obtained reaction liquid was performed, and it was confirmed that 2MeTHF was produced. The yield of 2MeTHF was 81.3%.

[0222] The present application has been described using specific examples, but it is obvious to those skilled in the art that various modifications can be made without departing from the intent and scope of the present application.

[0223] This application is based on Japanese Patent Application No. 2023-037807 filed on March 10, 2023, the contents of which are incorporated herein by reference in its entirety.

Claims

1. A catalyst for producing an alkyl group-containing unsaturated cyclic ether, which is a catalyst for producing an alkyl group-containing unsaturated cyclic ether (2) from an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group, and contains ruthenium and at least either one of tin or platinum.

2. The catalyst for producing an alkyl group-containing unsaturated cyclic ether according to claim 1, wherein the mass ratio of tin and platinum to ruthenium is 0.4 or more and 1.8 or less.

3. The catalyst for producing an alkyl group-containing unsaturated cyclic ether according to claim 1, wherein the catalyst is a metal support in which ruthenium and at least either one of tin or platinum is supported on a support.

4. The catalyst for producing an alkyl group-containing unsaturated cyclic ether according to claim 3, wherein the support is a carbonaceous support.

5. The catalyst for producing an alkyl group-containing unsaturated cyclic ether according to claim 1, wherein the unsaturated cyclic ether (1) is furfural, and the alkyl group-containing unsaturated cyclic ether (2) is 2-methylfuran.

6. A method for producing an alkyl group-containing unsaturated cyclic ether, the method comprising a reaction step of: subjecting an unsaturated cyclic ether (1) having a formyl group or a hydroxymethyl group to a hydrodeoxygenation reaction in the presence of a catalyst according to any one of claims 1 to 5, to obtain an alkyl group-containing unsaturated cyclic ether (2).

7. The method for producing an alkyl group-containing unsaturated cyclic ether according to claim 6, wherein the hydrodeoxygenation reaction is a liquid phase reaction in the presence of an organic solvent.

8. The method for producing an alkyl group-containing unsaturated cyclic ether according to claim 7, wherein the organic solvent is at least one selected from the group consisting of an ether compound, an alcohol compound, and an ester compound.

9. The method for producing an alkyl group-containing unsaturated cyclic ether according to claim 6, wherein the reaction temperature of the hydrodeoxygenation reaction is 185°C or higher.

10. A method for producing an alkyl-containing saturated cyclic ether, the method for producing an alkyl-containing saturated cyclic ether comprising: a hydrodeoxygenation reaction step of obtaining an alkyl group-containing unsaturated cyclic ether by the method for producing an alkyl group-containing unsaturated cyclic ether according to any one of claims 6 to 9; and a hydrogenation reaction step of subjecting the obtained alkyl group-containing unsaturated cyclic ether to a hydrogenation reaction in the presence of a noble metal catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of the elements, to obtain an alkyl group-containing saturated cyclic ether.

11. A method for producing an alkyl-containing saturated cyclic ether, the method for producing an alkyl-containing saturated cyclic ether comprising: an alkyl group-containing unsaturated cyclic ether is obtained by the method for producing an alkyl group-containing unsaturated cyclic ether according to any one of claims 6 to 9; and a noble metal catalyst containing at least one selected from the group consisting of a Group 8 noble metal and a Group 10 noble metal of the long form of the periodic table of the elements is added to the obtained alkyl group-containing unsaturated cyclic ether, and a hydrogenation reaction is performed, to obtain an alkyl group-containing saturated cyclic ether.

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