JP7333558B2 - Solid Lewis acid catalyst molded body - Google Patents

Description

The present invention relates to a solid Lewis acid catalyst shaped article and a method for producing hydroxymethylfurfural from a carbohydrate compound.

Hydroxymethylfurfural is an important chemical intermediate that can be synthesized from glucose, but its synthetic route is very complicated. Glucose, a raw material, undergoes skeletal isomerization in the presence of an acid catalyst and is converted to fructose. The fructose produced changes to hydroxymethylfurfural through a dehydration reaction with an acid catalyst, but hydroxymethylfurfural is further hydrolyzed sequentially by the acid catalyst in the reaction system to become organic acids (formic acid, levulinic acid). . Therefore, a novel catalyst for producing hydroxymethylfurfural with high selectivity is desired.

In Patent Document 1, by treating an amorphous hydrous titanium oxide with phosphoric acid, a phosphorylated titanium oxide in which a phosphoric acid residue is covalently bonded to the surface of the hydrous titanium oxide is obtained. discloses that it can exhibit excellent performance as a solid Lewis acid catalyst.

Patent Document 2 discloses a solid catalyst for the hydride isomerization reaction of glucose to fructose in water or an aqueous solution, which consists of an oxide of group 13 element whose surface is treated with phosphoric acid. Furthermore, Patent Document 2 mentions in the Background Art column that a reaction using phosphoric acid/TiO ₂ or phosphoric acid/Nb ₂ O as a catalyst is known in a method for producing 5-hydroxymethylfurfural from an aqueous glucose solution. Teaching.

Non-Patent Document 1 discloses phosphate-fixed titanium oxide obtained by adding titanium oxide to a phosphoric acid aqueous solution and stirring at room temperature for 48 hours to fix phosphoric acid on the surface hydroxyl groups of titanium oxide. They also stated that phosphate-fixed titanium oxide had high catalytic activity in aqueous solution for lactic acid synthesis from triose or furfural synthesis from xylose.

Non-Patent Document 2 states that in the reaction of converting 1,3-dihydroxyacetone to lactic acid, phosphoric acid-treated titanium oxide exhibited high catalytic activity due to Lewis acid sites that function in the presence of water.

WO2012/108472A1 WO2015/137339A1 JP-A-2000-63110

Nakajima et al., "Lewis Acid Properties of Titanium Dioxide in Water," Abstracts from the 42nd Petroleum and Petrochemical Symposium (Akita) Session ID: 1D03 Nakajima et al., "Lactic Acid Synthesis from Triose in Aqueous Solution with Solid Lewis Acid," 44th Petroleum and Petrochemical Symposium (Asahikawa Meeting) Abstract Session ID: 1D08

An object of the present invention is to provide a solid Lewis acid catalyst molded article and a method for producing hydroxymethylfurfural from a sugar compound.

As a result of investigations to solve the above problems, the present invention including the following aspects has been completed.

[1] A solid Lewis acid catalyst molded article containing a solid Lewis acid obtained by covalently bonding a phosphoric acid residue to a titanium oxide, and a binder.

[2] The solid Lewis acid catalyst shaped article according to [1], wherein the binder is at least one selected from the group consisting of polytetrafluoroethylene, aluminum oxide, silicone, silica, permethylsilane, and carbon black.
[3] The molded solid Lewis acid catalyst according to [1] or [2], wherein the amount of the binder is 10 to 100 parts by mass per 100 parts by mass of the solid Lewis acid.
[4] The shaped solid Lewis acid catalyst according to any one of [1] to [3], wherein the titanium oxide is an amorphous hydrous titanium oxide.
[5] The shaped solid Lewis acid catalyst according to any one of [1] to [4], wherein the titanium oxide is a hydrolysis product of a titanium oxide precursor.
[6] The shaped solid Lewis acid catalyst according to [5], wherein the titanium oxide precursor is at least one selected from the group consisting of titanium chlorides, titanium sulfates and titanium alkoxides.

[7] Producing hydroxymethylfurfural, comprising reacting a carbohydrate compound in a solvent in the presence of the shaped solid Lewis acid catalyst according to any one of [1] to [6] above. Method.
[8] The method of [7], further comprising contacting the liquid obtained by the reaction with activated carbon.

The solid Lewis acid catalyst molded body of the present invention has sufficient strength and does not collapse even in long-term reaction. Hydroxymethylfurfural can be obtained in a high yield from a sugar compound using the solid Lewis acid catalyst shaped article of the present invention.

The solid Lewis acid catalyst molded article of the present invention contains a solid Lewis acid and a binder.

The solid Lewis acid used in the present invention is obtained by covalently bonding a phosphoric acid residue to a titanium oxide.

The titanium oxide is preferably amorphous hydrous titanium oxide. Titanium oxide can be a hydrolysis product of a titanium oxide precursor. Titanium oxide precursors include inorganic titanium compounds such as titanium hydroxide, titanic acid, titanium trichloride, titanium tetrachloride, titanium tetrabromide, titanium sulfate, titanium oxysulfate; tetraisopropoxytitanium, tetra-n-butoxy titanium alkoxide compounds such as titanium, tetrakis(2-ethylhexyloxy)titanium, tetrastearyloxytitanium; titanium acylate compounds; diisopropoxybis(acetylacetonato)titanium, isopropoxy(2-ethyl 1,3-hexanedio titanium chelate compounds such as lacto)titanium and hydroxybis(lactato)titanium; organic titanium compounds such as titanium oxalate and titanium tetraacetate; and water-soluble titanium complexes. In the present invention, titanium oxide is preferably a hydrolysis product of titanium chloride, titanium sulfate, or titanium alkoxide.

Titanium oxide, especially amorphous hydrous titanium oxide, can be obtained by hydrolyzing titanium chloride, titanium sulfate or titanium alkoxide in the presence of an acid or a base. The number of carbon atoms constituting the alkoxy group in the titanium alkoxide is preferably 1-6, more preferably 2-4. Alkoxy groups can be straight, branched, or cyclic.
Acids used in the hydrolysis reaction include hydrochloric acid, sulfuric acid, nitric acid and the like. Examples of the base used in the hydrolysis reaction include ammonia, sodium hydroxide, potassium hydroxide and the like.
The temperature during the hydrolysis reaction is preferably 10 to 100°C, more preferably 20 to 30°C. The time required for the hydrolysis reaction can be appropriately set depending on the reaction temperature, reaction scale, etc., but it is preferably 0.5 hours to 48 hours, more preferably 10 hours to 24 hours.

Whether or not the titanium oxide contains water can be confirmed by surface measurement using an infrared spectrophotometer, weight reduction due to heat dehydration under vacuum, and the like. Moreover, it can be checked by X-ray diffraction whether the titanium oxide is amorphous or not. The term "amorphous" as used in the present invention means including an amorphous portion that can be confirmed by X-ray diffraction, and includes not only titanium oxide that is entirely amorphous, but also partially amorphous. . The amorphous pattern confirmed by X-ray diffraction specifically refers to a broad wave pattern without a clear crystal diffraction pattern.

Phosphate residues can be covalently attached to titanium oxides by treating the titanium oxides with phosphoric acid.
The phosphoric acid treatment can be performed by immersing titanium oxide in an aqueous solution of phosphoric acid and stirring. The temperature at this time is preferably 10° C. or higher and lower than 100° C., more preferably 20° C. or higher and 30° C. or lower. The reaction time can be appropriately set according to the reaction temperature, reaction scale, etc., preferably 1 hour to 96 hours, more preferably 24 hours to 72 hours. As described in Patent Document 3, titanium phosphate appears to be obtained when a mixture of titanium oxide and an aqueous solution of phosphoric acid is heated in a sealed state to a temperature of 100° C. or higher.

In the FT-IR spectrum of the solid Lewis acid used in the present invention, a signal (peak) derived from PO bond stretching vibration appears in the vicinity of 1000 cm ⁻¹ .
Incidentally, in the titanium oxide before the phosphoric acid treatment, no peak appears in the vicinity of 1000 cm ⁻¹ . The peak near 1000 cm ⁻¹ indicates that phosphoric acid is covalently bonded to the hydroxyl group (Ti—OH) on the surface of the titanium oxide skeleton, that is, the chemical structure of Ti—O—PO(OH) ₂ is formed. indicates that

The solid Lewis acid used in the present invention may be doped with a metal element or coated with a compound containing a metal element. Metal elements include aluminum, gallium, indium, thallium, magnesium, manganese, calcium, niobium, tantalum, zirconium, silicon, zinc, cerium, iron, tungsten, molybdenum, and vanadium.

Examples of binders used in the present invention include mordenite, chabasite, erionite, ferrierite, faujasite, levine, ZSM-5, zeolite A, zeolite β, FU-1, Rho, ZK-5, RUB- 3, crystalline aluminosilicate molecular sieves such as RUB-13, NU-3, NU-4, NU-5, NU-10, NU-13, NU-23, MCM-22; SAPO-5, SAPO-11, SAPO-17, SAPO-18, SAPO-26, SAPO-31, SAPO-33, SAPO-34, SAPO-35, SAPO-42, SAPO-43, SAPO-44, SAPO-47, SAPO-56, etc. Crystalline silicoaluminophosphate molecular sieves; silica, alumina (aluminum oxide), titania, zirconia, yttria; polytetrafluoroethylene, silicone, permethylsilane, carbon black and the like. Among these, at least one selected from the group consisting of polytetrafluoroethylene, aluminum oxide, silicone, silica, permethylsilane, and carbon black is preferred.

The amount of the binder is not particularly limited as long as the molded catalyst can be produced. part by mass.

The production method of the solid Lewis acid catalyst molded article of the present invention is not particularly limited. The solid Lewis acid catalyst molded article of the present invention can be obtained, for example, by kneading a binder and a solid Lewis acid together with water if necessary, molding, drying, and calcining if necessary. Kneading is preferably performed under pressure. From the viewpoint of workability, the kneading is preferably carried out continuously using a kneader such as a kneader.

The solid Lewis acid catalyst shaped bodies of the present invention can have forms such as powders, granules, pellets, thin films, nanotubes, etc., as desired.
The molding of the kneaded product is not particularly limited as long as it can be formed into a desired shape. For example, molding can be performed by an extrusion molding method, a compression molding method (for example, a tablet molding method, etc.), a roll molding method, a spray drying method, or the like.
The drying conditions are not limited as long as water can be removed.
After drying, it is arranged in a desired size and, if necessary, baked. The calcination temperature and time vary depending on the type of solid Lewis acid catalyst molded article. Firing can be performed, for example, at 400° C. to 700° C. for 1 to 10 hours.

The solid Lewis acid catalyst molded article of the present invention is obtained by mixing a binder precursor such as tetraethoxysilane, the titanium oxide precursor described above, and phosphoric acid or a precursor thereof to form a liquid or slurry, which is then cast, by slush molding, coating, etc., followed by hydrolysis, or by mixing a binder precursor such as tetraethoxysilane with the aforementioned titanium oxide precursor to form a liquid or slurry, which is then cast, slush molded, and coated. etc., followed by hydrolysis and phosphoric acid treatment.

The shaped solid Lewis acid catalyst of the present invention is not deactivated even in water, so it can be used to catalyze chemical reactions in water. Chemical reactions that can be catalyzed by the shaped solid Lewis acid catalyst of the present invention include dehydration reactions, allylation reactions, aldol condensation reactions, Michael addition reactions, alkylation reactions, isomerization reactions, hydrolysis reactions, and the like. .

Examples of preferred chemical reactions include skeletal isomerization of sugars followed by dehydration reaction, allylation reaction of aldehydes, and the like. Specific examples include the reaction of producing hydroxymethylfurfural from a carbohydrate compound such as glucose, the reaction of aldehyde and allyl metal, more specifically the reaction of benzaldehyde and tetraallyl tin, and the like. The ability to function as a Lewis acid can be confirmed by IR measurement to determine whether or not carbon monoxide (CO) molecules are adsorbed to the Lewis acid sites of the solid Lewis acid catalyst molded article at -190°C. A peak appears in the region of 2200 to 2165 cm ^-1 when adsorbed on the Lewis acid site.

The reaction using the shaped solid Lewis acid catalyst of the present invention may be carried out in a batch system or in a flow system, but is preferably carried out in a flow system. In the flow system, it is preferable to use a flow microreaction (microreactor). A chemical reaction is carried out by pouring raw materials into the channel filled with the shaped solid Lewis acid catalyst of the present invention. In the flow microreaction, the flow effect and the micromixing effect are expected to improve the reaction yield, relax the reaction conditions, and simplify the operation.

The method for producing hydroxymethylfurfural of the present invention includes reacting a carbohydrate compound in the presence of a solid Lewis acid catalyst shaped article in a solvent. Water is preferred as the solvent used in this reaction. Glucose etc. can be mentioned as a carbohydrate compound. The temperature during the reaction is preferably 80°C to 180°C, more preferably 110°C to 130°C. The time required for the reaction is appropriately selected according to the reaction temperature, preferably 10 minutes to 24 hours, more preferably 2 hours to 6 hours. The amount of the carbohydrate compound to be subjected to the reaction is preferably 0.0002 to 200 parts by mass, more preferably 0.025 to 2 parts by mass, per 1 part by mass of the solid Lewis acid in the solid Lewis acid catalyst molded article. is.

In the method for producing hydroxymethylfurfural of the present invention, heating the carbohydrate compound facilitates the progress of the Maillard reaction. Maillard reaction products can coat solid Lewis acid catalyst compacts and reduce their activity. In order to improve the yield of hydroxymethylfurfural, known Maillard reaction inhibitors, Maillard reaction product decomposing agents, and the like can be used. Examples of Maillard reaction inhibitors include monosulfide compounds, catechins, tocopherols, compounds obtained by binding tocopherols and ascorbic acid via a phosphate ester, and the like. Examples of Maillard reaction product decomposing agents include riboflavin derivatives, flavin adenine mononucleotide, flavin adenine dinucleotide, Japanese pepper soft extract, turmeric extract, saffron tincture, mint soft extract, ginger extract, carrot extract, lotus leaf extract, Red Pepper Extract, Coleus Forskohlii Extract, Yellow Leaf Extract, Hihatsu Extract, Japanese Peppermint Flower Powder, Hikiokoshi Extract, Shikwasa Extract, Kudzu Root Extract, Pu-erh Tea Extract, Licorice Extract, Black Rice Extract, Evening Primrose Extract, Guava Leaf Extract, Loquat Leaf Extract, Onion Peel extract, blue flower extract, mulberry leaf extract, cod bud extract, Chinese artichoke extract, white kidney bean extract, Raffia hemp extract, kumazasa extract, bitter gourd extract, Jerusalem artichoke extract, young barley leaf extract, brown algae extract, konjac potato extract, coffee bean extract , grape seed extract, apple extract, olive leaf extract, kelp extract, Angelica keiskei powder, catechin, kumquat soft extract, kumquat extract, kumquat extract, citrus extract, yuzu powder, chimpi extract, and the like.

In the method for producing hydroxymethylfurfural of the present invention, it is preferable to bring the liquid obtained by the above-described reaction of the carbohydrate compound into contact with activated carbon. By-products can be removed by contact with activated carbon to increase the purity of hydroxymethylfurfural.

The invention will now be described in more detail with reference to examples. In addition, the scope of the present invention is not limited by the examples.

Production Example 20 ml of titanium tetraisopropoxide was added to 100 ml of distilled water and stirred at room temperature for 3 hours. A white precipitate was removed from this by filtration, added to 200 ml of a 1.0 M hydrochloric acid aqueous solution, and stirred for 1 hour to promote condensation of the oxide skeleton. This filtration, addition and stirring (condensation) was repeated two more times (3 times total). The resulting precipitate was washed with distilled water until it became neutral and then dried in an oven at 80° C. to obtain an amorphous hydrous titanium oxide.
This amorphous hydrous titanium oxide was added to an aqueous phosphoric acid solution (0.1 M) and stirred at room temperature for 48 hours. A white solid was removed by filtration and washed with distilled water until neutral to obtain a solid Lewis acid.

Example 1
0.3 g of polytetrafluoroethylene was added to 1 g (dry weight) of solid Lewis acid and mixed. This was pressurized to obtain a sheet. This sheet was crushed. The pulverized material was classified with a sieve having an opening of 90 μm, and a powdery solid Lewis acid catalyst compact 1 was obtained on the sieve.

Example 2
To 1 g (dry weight) of solid Lewis acid, 0.3 g of silica sol (Snowtex C: manufactured by Nissan Chemical Industries, Ltd.) and 3 ml of distilled water were added and mixed with an ultrasonic stirrer. It was dried overnight at 100°C. The dried product obtained was crushed with a spatula. This was classified with a sieve having an opening of 90 μm, and a powdery solid Lewis acid catalyst compact 2 was obtained on the sieve.

Example 3
0.15 g of aluminum oxide, 0.15 g of polydimethylsilane and 5 ml of hexane were added to 1 g (dry weight) of solid Lewis acid and mixed with an ultrasonic stirrer. It was dried overnight at room temperature. The dried product obtained was crushed with a spatula. This was classified with a sieve having an opening of 90 μm, and a powdery solid Lewis acid catalyst molded body 3 was obtained on the sieve.

Example 4
3 ml of hexane was added to 0.2 g of a silicone compound (Siloprene RTV-2K 1406; manufactured by Bayer) and mixed with an ultrasonic stirrer. 1 g (dry weight) of a solid Lewis acid and 20 μl of a curing agent for silicone (Siloprene R-14; manufactured by Bayer AG) were added thereto and mixed with an ultrasonic stirrer. It was dried overnight at room temperature. The dried product obtained was crushed with a spatula. This was classified with a sieve having an opening of 90 μm, and a powdery solid Lewis acid catalyst compact 4 was obtained on the sieve.

Example 5
0.757 g of solid Lewis acid catalyst molded article 1 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 500 mM glucose aqueous solution was passed through the column set at a temperature of 120° C. at 40 μl/min. Aqueous solution A discharged through the column and s-butylphenol were mixed with a micromixer (β mixer; manufactured by MiChS) to obtain a liquid consisting of 6.3 ml of an aqueous layer and 7.7 ml of an organic layer. This liquid was analyzed.
The aqueous layer contained 15.3 mM hydroxymethylfurfural, 157.7 mM glucose, 9.9 mM fructose, and 0.9 mM cellobiose.
The organic layer contained 126.5 mM hydroxymethylfurfural. Glucose, fructose and cellobiose were not detected in the organic layer.
The conversion of glucose to hydroxymethylfurfural was 71.6% and the selectivity was 42.8%.

Example 6
1.077 g of solid Lewis acid catalyst molded body 2 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 595 mM aqueous glucose solution was passed through the column set at a temperature of 110° C. at 40 μl/min. Aqueous solution B discharged through the column and s-butylphenol were mixed with a micromixer (β mixer; manufactured by MiChS) to obtain a liquid consisting of 13.8 ml of an aqueous layer and 13.8 ml of an organic layer. This liquid was analyzed.
The aqueous layer contained 13.2 mM hydroxymethylfurfural, 237.2 mM glucose, 15.1 mM fructose, and 1.3 mM cellobiose.
The organic layer contained 128.0 mM hydroxymethylfurfural. Glucose, fructose and cellobiose were not detected in the organic layer.
The conversion of glucose to hydroxymethylfurfural was 59.3% and the selectivity was 40.9%.

Example 7
0.855 g of the solid Lewis acid catalyst molded body 2 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 525 mM aqueous glucose solution was passed through the column set at a temperature of 110° C. at 40 μl/min. Aqueous solution C discharged through the column was analyzed.
Aqueous solution C contained 32.3 mM hydroxymethylfurfural, 442.7 mM glucose, 24.7 mM fructose, and 0.5 mM cellobiose.

Example 8
0.809 g of the solid Lewis acid catalyst molded body 3 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 10% by mass glucose aqueous solution was passed through the column set at a temperature of 110° C. at 40 μl/min. Aqueous solution D discharged through the column was analyzed.
Aqueous solution D contained 76.5 mM hydroxymethylfurfural, 386.5 mM glucose, 24.6 mM fructose, and 0.9 mM cellobiose.
The conversion of glucose to hydroxymethylfurfural was 30.4% and the selectivity was 45.2%.

Example 9
1.206 g of the solid Lewis acid catalyst molded body 4 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 10% by mass glucose aqueous solution was passed through the column set at a temperature of 110° C. at 40 μl/min. The aqueous solution E discharged through the column was analyzed.
Aqueous solution E contained 35.1 mM hydroxymethylfurfural, 421.3 mM glucose, 11.3 mM fructose, and 48.3 mM cellobiose.

Example 10
1.1898 g of the solid Lewis acid catalyst molded body 4 was packed in a 4 mmφ×5 cm stainless steel column (manufactured by MiChS). A 575.6 mM glucose aqueous solution was passed through the column set at a temperature of 110° C. at 40 μl/min. The aqueous solution F discharged through the column was analyzed.
Aqueous solution F contained 22.5 mM hydroxymethylfurfural, 523.3 mM glucose, 7.1 mM fructose, and 8.8 mM cellobiose.
A 10 mmφ chromatography tube was filled with 1.8 g of activated carbon (manufactured by Fuji Film Wako, bulk specific gravity 0.182). 50 ml of the aqueous solution F was poured into this. Then, 20 ml of distilled water was passed through. Finally, 20 ml of methanol was flowed. The methanol discharged through the chromatographic tube contained 93% hydroxymethylfurfural and a total of 7% glucose, fructose and cellobiose.

Comparative Example A test tube was charged with 0.25 g of a solid Lewis acid, 1 ml of a 10% by mass glucose aqueous solution, and 3 ml of s-butylphenol, and the test tube was stirred at 110° C. for 3 hours. After the reaction, 3 ml of s-butylphenol layer and 1 ml of aqueous solution layer were obtained from the test tube. This liquid was analyzed.
The aqueous layer contained 4.64 mM hydroxymethylfurfural, 387.53 mM glucose, 18.34 mM fructose, and 2.13 mM cellobiose.
The s-butylphenol layer contained 24.27 mM hydroxymethylfurfural. Glucose, fructose and cellobiose were not detected in the organic layer.
The conversion of glucose to hydroxymethylfurfural was 23.7%.

Claims (7)

Containing a solid Lewis acid formed by covalently bonding a phosphoric acid residue to a titanium oxide, and a binder ,
the binder is at least one selected from the group consisting of polytetrafluoroethylene, aluminum oxide, silicone and permethylsilane ;
Solid Lewis acid catalyst shaped bodies. 2. The solid Lewis acid catalyst molded article according to claim 1 , wherein the amount of the binder is 10 to 100 parts by mass with respect to 100 parts by mass of the solid Lewis acid. 3. The shaped solid Lewis acid catalyst according to claim 1, wherein the titanium oxide is an amorphous hydrous titanium oxide. Solid Lewis acid catalyst shaped body according to any one of claims 1 to 3 , wherein the titanium oxide is a hydrolysis product of a titanium oxide precursor. 5. The shaped solid Lewis acid catalyst according to claim 4 , wherein the titanium oxide precursor is at least one selected from the group consisting of titanium chlorides, titanium sulfates and titanium alkoxides. A method for producing hydroxymethylfurfural, which comprises reacting a sugar compound in a solvent in the presence of the solid Lewis acid catalyst molded article according to any one of claims 1 to 5 . 7. The method of claim 6 , further comprising contacting the liquid resulting from the reaction with activated carbon.