JP5817794B2 - Method for demethylation or demethoxylation of aromatic compound having methoxy group - Google Patents

Description

  The present invention relates to a method for demethylating or demethoxylating an aromatic compound having a methoxy group.

  Aromatic compounds obtained by pyrolyzing or solubilizing substances contained in lignin or lignin-containing materials and further subjecting to demethylation or demethoxylation reaction are useful substances that can be used as chemicals, monomer raw materials, etc. Many are included.

Non-Patent Document 1 discloses ZrO ₂ —Al ₂ O in a fixed bed as a technique for producing phenol and the like by modifying a product mainly containing guaiacol (methoxyphenol) obtained by solubilizing lignin. It is disclosed that the reaction is carried out at 500 ° C. using a gas flow reactor in which a _3- FeOx catalyst is fixed. Non-Patent Document 2 discloses a homogeneous nickel carbene catalyst as a catalyst for breaking the bond with the aromatic C—O in the aryl ether.

However, the conventional method uses a ZrO ₂ —Al ₂ O ₃ —FeOx catalyst or a nickel carbene complex or other catalyst that requires time and effort, and there is a problem that the production of the catalyst is expensive. .

  Patent Document 1 is characterized by heat-treating lignin having poor reactivity using a zeolite carrying one or more metals selected from the group consisting of elements of Group 7 to Group 10 on the periodic table. Specifically, it is described that benzene and toluene were obtained by solubilizing lignin and then vaporizing it and subjecting it to a gas phase reaction. ing. However, it is not specifically described that catechol or phenol was obtained by this method.

  Patent Document 2 describes a method of solubilizing lignin by decomposing lignin or a lignin-containing material in water and an alcohol solvent in the presence of a solid acid catalyst. In the examples, it is described that γ-alumina is used as the solid acid catalyst. However, it is not specifically described that the solid acid catalyst has demethylation performance or demethoxylation performance, and further that catechol or phenol was obtained from lignin or a lignin-containing material.

  Therefore, there has been a demand for a technique that makes it possible to produce an industrially useful aromatic compound as described above on an industrial scale using a catalyst that can be easily prepared at low cost.

Japanese Patent Application Laid-Open No. 2011-127022 JP 2012-102297 A

J. Japan. Petro. Inst, 53 (3), 178-183 (2010), Takao Masuda et al. Science Vol. 332 no. 6028 pp. 439-443 (2011), Alexey G. Sergeevand John F. Hartwig

  The present invention relates to a method for producing a demethoxylated or demethoxylated aromatic compound from an aromatic compound having a methoxy group, in particular, a demethylation in a high yield using a catalyst that can be easily prepared at a low cost. Alternatively, it is an object to provide a method for producing a demethoxylated aromatic compound.

The present inventors have found that γ-alumina has high demethylation performance and demethoxylation performance, and have reached the present invention. That is, the present invention includes the following inventions.
(1) A method for producing an aromatic compound, wherein an aromatic compound having a methoxy group is subjected to demethylation or demethoxylation reaction in the presence of a catalyst containing γ-alumina.
(2) The method according to (1) above, wherein the catalyst further comprises an oxide of at least one metal selected from the group consisting of Ag, Zr and Ni.
(3) The method according to (1) or (2) above, wherein the catalyst further contains an oxide of Fe.
(4) The method according to any one of (1) to (3) above, wherein the catalyst further contains acidic silica.
(5) The method according to (4) above, wherein γ-alumina is supported on the acidic silica surface.
(6) The method according to any one of (1) to (5) above, wherein the aromatic compound having a methoxy group is guaiacol.
(7) The method according to any one of (1) to (6), wherein the reaction is performed in a liquid phase.
(8) A catalyst for demethylation or demethoxylation of an aromatic compound having a methoxy group, including γ-alumina.
(9) The catalyst according to (8), further including an oxide of at least one metal selected from the group consisting of Ag, Zr, and Ni.
(10) The catalyst according to (8) or (9), further including an oxide of Fe.
(11) The catalyst according to any one of (8) to (10), further comprising acidic silica.

  According to the present invention, an aromatic compound having a methoxy group can be demethylated or demethoxylated in a high yield using a catalyst that can be easily prepared at low cost.

FIG. 1 is a view showing an apparatus for carrying out the method of the present invention by a gas phase reaction. FIG. 2 is a diagram showing an apparatus for performing the method of the present invention by a liquid phase reaction. FIG. 3 is a graph showing the phenol yield obtained by the methods of Example 1-7 and Comparative Example 1-2. FIG. 4 is a graph showing the phenol yield obtained by the methods of Examples 1 and 8-10. FIG. 5 is a diagram showing the number of products (number of product species) obtained by the methods of Examples 1 and 8-10. FIG. 6 is a graph showing the phenol selectivity obtained by the methods of Examples 8 and 11-13. FIG. 7 is a graph showing the phenol selectivity obtained by the methods of Examples 9 and 14-16. FIG. 8 is a graph showing the phenol selectivity obtained by the methods of Examples 10 and 17-19. FIG. 9 is a graph showing the phenol yield obtained by the methods of Examples 20 and 21. FIG. 10 is a diagram showing the yield of aromatic compounds obtained by the methods of Examples 20 and 21. FIG. 11 is a graph showing the phenol yield obtained by the methods of Examples 8-10 and 22-26. FIG. 12 is a graph showing the phenol yield obtained by the methods of Examples 22 and 26-28.

  The present inventors have found that γ-alumina has high demethylation performance and demethoxylation performance, and an aromatic compound having a methoxy group is demethylated or demethoxylated in the presence of a catalyst containing γ-alumina. It has been found that an aromatic compound demethylated or demethoxylated in a high yield can be obtained by carrying out the conversion reaction. Furthermore, a catalyst having higher demethylation performance and demethoxylation performance can be obtained by including at least one metal oxide or acidic silica selected from the group consisting of Ag, Zr and Ni in the catalyst. I found out. The catalyst used in the present invention can be easily prepared at low cost.

  The aromatic compound having a methoxy group used in the method of the present invention is not particularly limited, but includes, for example, a compound obtained when lignin is decomposed or solubilized, and specifically includes guaiacol, anisole, and syringol. (2,6-dimethoxyphenol), 2-methoxy-4-methylphenol, isoeugenol and derivatives thereof are mentioned. Among these, guaiacol and anisole are preferable. Examples of the derivative include guaiacylglycerol-β-guaiacyl ether. Examples of the material containing lignin include palm tree trunks / air bunch, bagasse, rice straw, straw, corn residues (corn stover, corn cob, corn hull), Jatropha seed coat / shell, wood chip and the like. Examples of a method for solubilizing lignin include the method described in J. Japan. Petro. Inst, 53 (3), 178-183 (2010) Takao Masuda et al. According to this method, a mixture containing guaiacol as a main component can be obtained. The raw material used in the method of the present invention may contain other compounds as long as it contains an aromatic compound having at least one methoxy group as a main component.

  Specific examples of the aromatic compound obtained by the method of the present invention include phenol, catechol, cresol, 2-methylcatechol, 4-methylcatechol, pyrogallol, and 3-methoxycatechol. The cresol may be any of o-, m- and p-cresol, but o-cresol is preferred.

The catalyst used in the method of the present invention includes γ-alumina. By using γ-alumina, the modification rate of the aromatic compound having a methoxy group (reaction rate of the aromatic compound having a methoxy group) and the selectivity of the target product (the purpose included in the reaction product) As a result, the yield of the target product can be improved as compared with conventional catalysts (such as ZrO ₂ —Al ₂ O ₃ —FeOx catalyst). From the viewpoint of effectively exhibiting the effect, the content of γ-alumina is preferably 50 to 100% by mass, and particularly preferably 90 to 100% by mass with respect to the catalyst. As γ-alumina, commercially available activated alumina such as activated alumina KC-501 and KHS-46 manufactured by Sumitomo Chemical Co., Ltd. can be used. In addition, although the said content was computed based on the catalyst raw material, content of the said component in the obtained catalyst may reduce 0 to 3% compared with the content computed based on the catalyst raw material. There is.

The catalyst used in the method of the present invention preferably further contains an oxide of at least one metal selected from the group consisting of Ag, Zr and Ni, and particularly preferably contains an oxide of Ni. Examples of the oxides of Ag, Zr, and Ni include Ag ₂ O ₃ , ZrO _2, and NiO, respectively. Thereby, the yield of the target product can be improved. From the viewpoint of effectively exhibiting the effect, the molar ratio between the Al atomic weight of γ-alumina and the atomic weight of the metal is preferably 99.9: 0.1 to 98.0: 2.0. 85: 0.15 to 99.0: 1.0 is particularly preferable. The molar ratio between the Al atomic weight of the γ-alumina and the atomic weight of the metal is calculated based on the catalyst raw material. In the obtained catalyst, the ratio is preferably 99.9: 0.1. To 98.2: 1.8, particularly preferably 99.8: 0.2 to 99.2: 0.8.

The catalyst used in the method of the present invention preferably further contains an oxide of Fe. Examples of iron oxides include FeO, Fe ₃ O ₄ , Fe ₂ O ₃ , FeOOH, and mixtures thereof. Thereby, the yield of the target product can be improved. From the viewpoint of effectively exhibiting the effect, the molar ratio between the Al atomic weight of γ-alumina and the atomic weight of the metal is preferably 99.9: 0.1 to 98.0: 2.0. It is particularly preferable that the ratio is 85: 0.15 to 99.0: 1.5. The molar ratio between the Al atomic weight of the γ-alumina and the atomic weight of the metal is calculated based on the catalyst raw material. In the obtained catalyst, the ratio is preferably 99.9: 0.1. To 98.2: 1.8, particularly preferably 99.8: 0.2 to 99.2: 0.8.

  The catalyst used in the method of the present invention preferably further contains acidic silica. As a result, the number of reaction product species generated after the reaction can be reduced, and the target product from the reaction product can be purified more efficiently. In addition, since solid atoms such as acidic silica have H atoms on their surfaces, it is considered that H atoms can be efficiently supplied to the reaction system, and thus the reaction rate can be improved. From the viewpoint of effectively exhibiting the effect, the molar ratio between the Al atomic weight of γ-alumina and the Si atomic weight derived from acidic silica is preferably 97: 3 to 60:40, and 80:20 to 70:30. It is particularly preferred. In addition, since acidic silica has a large specific surface area, it is possible to ensure a large number of reaction points, and it is preferable that acidic silica be contained in the catalyst in a form in which γ-alumina is supported on the surface. The molar ratio between the Al atomic weight of the γ-alumina and the Si atomic weight derived from acidic silica is calculated based on the catalyst raw material. In the obtained catalyst, the ratio is preferably 96: 4 to 65. : 35, particularly preferably 80:20 to 75:25.

  The catalyst used in the method of the present invention preferably contains both acidic silica and an oxide of Ni in addition to γ-alumina from the viewpoint of further improving the selectivity of the target product. The content of Ni is preferably 0.1 to 2.0 mol% with respect to 100 mol% of the total molar amount of Al atomic weight of γ-alumina and Si atomic weight derived from acidic silica, It is especially preferable that it is 1.0 mol%. In addition, although the said content was computed based on the catalyst raw material, content of the said component in the obtained catalyst may reduce 0-5% compared with the content computed based on the catalyst raw material. There is.

  The catalyst used in the method of the present invention can be produced by an impregnation support method, an ion exchange method or the like.

  The catalyst used in the method of the present invention is preferably obtained by performing a calcination treatment, for example, in the air after drying and pulverization. The firing temperature is preferably 350 ° C to 800 ° C, and particularly preferably 450 ° C to 600 ° C. The firing treatment is preferably performed for 1 to 4.5 hours, particularly preferably 1.5 to 2.5 hours. By performing the baking treatment, the yield of the target product can be improved. In particular, when the method of the present invention is carried out in the gas phase, it is preferable to employ the above conditions.

  The demethylation reaction and the demethoxylation reaction according to the method of the present invention can be performed in a gas phase or a liquid phase.

  The method of the present invention is preferably carried out in the gas phase from the viewpoint of facilitating separation of the product after the reaction. The gas phase reaction can be performed using, for example, an apparatus as shown in FIG.

  When the method of the present invention is carried out in the gas phase, it is preferable to use water or carbon dioxide (particularly supercritical carbon dioxide) as the solvent, and it is particularly preferable to use water. Examples of water include normal water, ion exchange water, distilled water, and the like, and tap water, industrial water, and the like can also be used.

  When the method of the present invention is carried out in the gas phase, the mass ratio of the raw material (aromatic compound having a methoxy group) to the solvent is not particularly limited, but the catalyst is obtained by increasing the fluidity using a sufficient amount of solvent. From the viewpoint of making it easy to supply the raw material and suppressing the amount of heat consumed by the solvent from the economical aspect, it is usually 0.1 to 5, preferably 0.3 to 1.

  When performing the method of this invention in a gaseous phase, although mass ratio with respect to the raw material (aromatic compound which has a methoxy group) of a catalyst is not restrict | limited, Usually, it is 1-10000, Preferably it is 100-1000. The catalyst is preferably replaced when it starts to deteriorate, but it may be replaced when it is reduced by 50% from the initial activity in terms of economy. Moreover, you may use a catalyst, repeating reproduction | regeneration using a fluidized bed reaction apparatus.

  When the method of the present invention is carried out in the gas phase, the reaction temperature is not particularly limited, but is usually 350 to 550 ° C, preferably 400 to 500 ° C.

  When performing the method of this invention in a gaseous phase, although reaction time (contact time of a raw material and a catalyst) in particular is not restrict | limited, Usually, 0.01 to 1 second, Preferably it is 0.1 to 1 second.

  When performing the method of this invention in a gaseous phase, it is preferable to carry out in inert gas atmosphere, such as nitrogen and argon.

  When the method of the present invention is carried out in the gas phase, the reaction pressure (absolute pressure) is not particularly limited, but is preferably 0.1 (atmospheric pressure) to 1 MPa. More preferable conditions are appropriately set because they are affected by the solvent and temperature.

  The method of the present invention is preferably carried out in a liquid phase because it does not require energy for vaporizing the raw material and is economical. The liquid phase reaction can be performed using, for example, an apparatus as shown in FIG.

  When the method of the present invention is carried out in the liquid phase, it is preferable to use water, residual water after removing useful substances from the product after reaction, molten salt, ionic fluid, and water as the solvent. Particularly preferred. Examples of water include normal water, ion exchange water, distilled water, and the like, and tap water, industrial water, and the like can also be used.

  When the method of the present invention is performed in a liquid phase, the mass ratio of the raw material (aromatic compound having a methoxy group) to the solvent is not particularly limited, but is usually 0.1 to 0.1% from the viewpoint of ensuring the uniformity of the reaction product. 100, preferably 1-20. In the case of a liquid phase reaction, the reaction can be performed in the form of a high concentration slurry.

  When performing the method of this invention in a liquid phase, the mass ratio with respect to the raw material (aromatic compound which has a methoxy group) of a catalyst is although it does not restrict | limit, Usually, it is 1-100, Preferably it is 1-50.

  When the method of the present invention is performed in a liquid phase, the reaction temperature is not particularly limited, but is usually 300 to 400 ° C.

  When the method of the present invention is carried out in the liquid phase, the reaction time is not particularly limited, but is usually 0.5 to 3 hours, preferably 1 to 2 hours.

  When performing the method of this invention in a liquid phase, it is preferable to carry out in the atmosphere of inert gas, such as nitrogen and argon, or oxygen-containing atmosphere, such as air | atmosphere.

  When the method of the present invention is performed in a liquid phase, the reaction pressure is not particularly limited, but is preferably 5 to 15 MPa. More preferable conditions are appropriately set because they are affected by the solvent and temperature.

  The product obtained by the method of the present invention can be separated and purified from the reaction solution by usual methods such as column chromatography, recrystallization method, and solvent extraction method. For product identification, various means such as elemental analysis, NMR spectrum, IR spectrum, and mass spectrometry are used.

  Aromatic compounds such as catechol and phenol obtained by the method of the present invention can be used as chemical products and monomer raw materials.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the range of an Example.

Example 1-21 and Comparative Example 1-2
The procedure of gas phase reaction vapor phase reaction is described below with reference to FIG.
In the apparatus shown in FIG. 1, two bubbling traps for trapping the product after the reaction are provided on the downstream side of the reaction tube in which the catalyst is set. Acetone was placed in the bubbling trap A, and the product was trapped at 0 ° C. (ice cooling). Further, acetone / water = 6 mL / 2 mL solution was placed in the downstream bubbling trap B, and the product that could not be removed by the bubbling trap A was trapped. An opening for introducing guaiacol (methoxyphenol) and nitrogen + water vapor was provided upstream of the reaction tube made of quartz.

About 0.5 g of the catalyst was set in a place where the tubular furnace of the apparatus set as described above was in the soaking zone. Nitrogen and water vapor were allowed to flow from the upstream side for 30 minutes to adjust the gas atmosphere in the reaction tube (nitrogen flow rate 100 cc / min, saturated vapor amount 22.5 g / m ³ ). Next, the tubular furnace was set at 500 ° C., and it was confirmed by a thermocouple (not shown) that the catalyst temperature reached 500 ° C.

  In a state where nitrogen and water vapor were circulated, the raw material guaiacol was directly brought into contact with the catalyst through a thin tube to initiate the reaction.

  After 5 minutes, the gas flow was stopped, and the reaction product trapped in the two traps was subjected to gas chromatography (FID-GC [manufactured by Shimadzu Corporation, FID-GC2010plus], column DB-17MS [manufactured by Agilent Technologies]). And analyzed.

Liquid Phase Reaction The liquid phase reaction was carried out by the following procedure using an SUS autoclave as shown in FIG.
A predetermined amount of guaiacol, water and catalyst were put in this order in the autoclave, and the temperature was raised while stirring at 200 rpm. After maintaining the predetermined temperature for 2 hours, the stirring was stopped and the mixture was rapidly cooled. During the reaction, the pressure was measured with a pressure gauge attached to the autoclave.
Analysis of the product after the liquid phase reaction was performed as follows.

  After centrifuging the liquid remaining in the autoclave, the supernatant was dissolved in acetone, and gas chromatography (FID-GC [manufactured by Shimadzu Corporation, FID-GC2010plus], column DB-17MS [manufactured by Agilent Technologies]) was used. And analyzed. Furthermore, after the autoclave reaches room temperature, the internal gas is collected with a syringe, and gas chromatography (TCD-GC [manufactured by Shimadzu Corp., TCD-GC2010plus], FID-GC [manufactured by Shimadzu Corp., FID-GC2010plus]) is used. The generated gas was analyzed.

[Example 1]
Using a catalyst obtained by calcining activated alumina KC-501 manufactured by Sumitomo Chemical Co., Ltd. (available from Sumika Alchem Co., Ltd.) at 400 ° C. for 2 hours, a gas phase reaction was performed under the conditions shown in Table 1. It was.

[Example 2]
Silver was supported on activated alumina KC-501 (available from Sumika Alchem Co., Ltd.) manufactured by Sumitomo Chemical Co., Ltd. by the following method.

  A 500 cc beaker was charged with 150 cc to 200 cc of ion exchange water, and activated alumina KC-501 (about 10 g) was added. The resulting solution was stirred for about 10 minutes at 200 rpm at room temperature.

  Silver nitrate (manufactured by Nacalai Tesque) was added in an amount such that Al atomic weight: Ag atomic weight = 99: 1 (mol) of activated alumina KC-501, and stirred at room temperature for about 10 minutes at 200 rpm.

  Thereafter, the solution was stirred using a hot stirrer set to 80 ° C. until the water evaporated, and then dried in a 120 ° C. dryer (Air atmosphere) for a whole day and night.

The obtained powder was pulverized for about 5 minutes in an agate mortar, and the pulverized powder was baked in a 400 ° C. electric furnace (Air atmosphere) for 2 hours. Further, the obtained powder was pulverized in an agate mortar for about 5 minutes to obtain a catalyst.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 3]
The catalyst was prepared in the same manner as in Example 2 except that copper (II) oxide (manufactured by Nacalai Tesque) was used instead of silver nitrate in an amount such that the Al atomic weight of the activated alumina KC-501: Cu atomic weight = 99: 1 (mol). Obtained.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 4]
A catalyst was obtained in the same manner as in Example 2 except that zirconium oxychloride (manufactured by Nacalai Tesque) was used instead of silver nitrate in such an amount that the Al atomic weight of the activated alumina KC-501: Zr atomic weight = 99: 1 (mol). .
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 5]
A catalyst was prepared in the same manner as in Example 2 except that nickel nitrate (manufactured by Nacalai Tesque) was used instead of silver nitrate in an amount of Al atom weight of activated alumina KC-501: Ni atom weight = 99.85: 0.15 (mol). Got.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 6]
A catalyst was prepared in the same manner as in Example 2 except that nickel nitrate (manufactured by Nacalai Tesque) was used instead of silver nitrate in an amount of Al atom weight of activated alumina KC-501: Ni atom weight = 99.30: 0.70 (mol). Got.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 7]
A catalyst was obtained in the same manner as in Example 2 except that nickel nitrate (manufactured by Nacalai Tesque) was used instead of silver nitrate in an amount of Al atom weight: Ni atom weight of activated alumina KC-501 = 99: 1 (mol).
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 8]
In a 500 cc beaker, 150 cc to 200 cc of ion exchange water was added, acidic silica [manufactured by Rhodia] (about 0.5 g) was added, and the mixture was stirred at room temperature at 200 rpm for about 10 minutes.

  Aluminum nitrate nonahydrate (manufactured by Nacalai Tesque) was added in such an amount that the Al atomic weight of aluminum nitrate: Si atomic weight = 95: 5 (mol), and the mixture was stirred at 200 rpm at room temperature for about 10 minutes.

  Thereafter, using a hot stirrer set at 60 ° C., the solution was stirred at a low speed until water evaporated, and then dried for a whole day and night in a 120 ° C. dryer (Air atmosphere).

  The obtained powder was pulverized in an agate mortar for about 5 minutes, and the pulverized powder was baked in a 700 ° C. electric furnace (Air atmosphere) for 4 hours. Further, the obtained powder was pulverized in an agate mortar for about 5 minutes to obtain a catalyst.

For acidic silica, a temperature-desorption method measuring device (Temperature-Programmed Desorption: TPD) is used to adsorb ammonia, which is a base probe molecule, to acidic silica support (SiO ₂ ), and then the catalyst temperature is raised to 100 ° C. Those having an acidic property in which the amount of ammonia desorbed up to ˜550 ° C. was 0.65 mmol / g per weight of acidic silica support were used.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 9]
A catalyst was obtained in the same manner as in Example 8 except that acidic silica and aluminum nitrate nonahydrate were used in an amount of Al atomic weight: Si atomic weight of aluminum nitrate = 90: 10 (mol).
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 10]
A catalyst was obtained in the same manner as in Example 8 except that acidic silica and aluminum nitrate nonahydrate were used in an amount of Al atomic weight: Si atomic weight of aluminum nitrate = 80: 20 (mol).
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 11]
1 g of the catalyst obtained in Example 8 was put into 150 cc to 200 cc of ion exchange water, and stirred at room temperature at 200 rpm for about 10 minutes.

  Nickel (II) nitrate hexahydrate (manufactured by Nacalai Tesque) was added in an amount of aluminum nitrate such that Al atomic weight: Si atomic weight: Ni atomic weight = 95: 5: 0.15 (mol), and about 200 rpm at room temperature. Stir for 10 minutes.

  Thereafter, the solution was stirred using a hot stirrer set to 80 ° C. until the water evaporated, and then dried in a 120 ° C. dryer (Air atmosphere) for a whole day and night.

The obtained powder was pulverized for about 5 minutes in an agate mortar, and the pulverized powder was baked in a 400 ° C. electric furnace (Air atmosphere) for 2 hours. Furthermore, after the obtained powder was returned to room temperature, it was ground in an agate mortar for about 5 minutes to obtain a catalyst.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 12]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 95: 5: 0.7 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 13]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 95: 5: 1.0 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 14]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 90: 10: 0.15 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 15]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 90: 10: 0.7 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 16]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 90: 10: 1.0 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 17]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 80: 20: 0.15 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 18]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 80: 20: 0.7 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 19]
A catalyst was obtained in the same manner as in Example 11 except that nickel nitrate was used in an amount of Al atomic weight: Si atomic weight: Ni atomic weight = 80: 20: 1.0 (mol) of aluminum nitrate.
A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.

[Example 20]
Using a catalyst obtained by calcining activated alumina KC-501 (available from Sumika Alchem Co., Ltd.) manufactured by Sumitomo Chemical Co., Ltd. at 400 ° C. for 2 hours, a liquid phase reaction was performed under the conditions shown in Table 1. It was. The autoclave capacity was 40 mL.

[Example 21]
Using a catalyst obtained by calcining activated alumina KC-501 (available from Sumika Alchem Co., Ltd.) manufactured by Sumitomo Chemical Co., Ltd. at 400 ° C. for 2 hours, a liquid phase reaction was performed under the conditions shown in Table 1. It was. The autoclave capacity was 200 mL.

[Comparative Example 1]
Gas phase reactions were carried out under the conditions shown in Table 1 without using a catalyst.

[Comparative Example 2]
An iron-aluminum-zirconia catalyst was synthesized as follows with reference to the method described in J. Japan. Petro. Inst, 53 (3), 178-183 (2010).

To 1.5 L of distilled water under stirring in a Teflon beaker, Fe (NO ₃ ) ₃ -9H ₂ O (226.2 g), Al (NO ₃ ) ₃ -9H ₂ O (52.5 g) and ZrOCl ₂ -8H ₂ O (11.3 g) was added in this order to dissolve everything and stirred for about 2 hours. While the obtained solution was stirred, 48.7% NaOH aqueous solution (300 g) was added dropwise at 320 μl / min to cause coprecipitation. Stirring was continued all day and night after the completion of the dropwise addition.

After washing with hot water at 70 ° C. to 80 ° C. until the pH reached 7-8, solid-liquid separation was performed, and the resulting cake-like solid was dried at 120 ° C. overnight.
The dried solid was pulverized in an agate mortar and baked at 700 ° C. for 4 hours.

A gas phase reaction was performed under the conditions shown in Table 1 using the obtained catalyst.
The reaction conditions and results of Example 1-21 and Comparative Examples 1 and 2 are shown in Table 1.

  From FIG. 3, when γ-alumina is used (Example 1), the yield of phenol is improved as compared with the case where no catalyst is used (Comparative Example 1) and the case where a conventional Fe-based catalyst is used (Comparative Example 2). I understand that In addition, when a catalyst further containing oxides of Ag, Zr, and Ni was used (Examples 2 and 4-7), the phenol yield was lower than when γ-alumina alone (Example 1) was used. Remarkably improved.

  4 and 5, when the acidic silica is further supported on γ-alumina (Example 8-10), the phenol yield is improved as compared with the case where γ-alumina is used alone (Example 1), and It can be seen that the number of product species (the number of products detectable as a peak of 0.002% or more which is the gas chromatography detection limit) is reduced.

  6 and 7, when a catalyst (Examples 11-13 and 14-16) further containing Ni oxide in γ-alumina and acidic silica was used, no Ni oxide was contained (Examples). It can be seen that the phenol selectivity is improved as compared with 8, 9). When 5% or 10% of acidic silica was supported, the activity was most improved when Ni was 1.0%. On the other hand, as shown in FIG. 8, when 20% acidic silica was supported, the activity of phenol selectivity was most improved when Ni was 0.15%. This is presumably because the catalytic activity increases excessively as the amount of Ni increases, and the produced phenol changes to another compound.

  When a liquid phase reaction is performed using γ-alumina, the phenol yield is remarkably improved at a reaction temperature of 350 ° C. (Example 20) (FIG. 9), and catechol is mainly used at a reaction temperature of 300 ° C. (Example 21). The yield of aromatic compounds as components was significantly improved (FIG. 10).

Examples 22-28
Gas phase reaction [Example 22]
In a 500 cc beaker, 150 cc to 200 cc of ion exchange water was added, acidic silica [manufactured by Rhodia] (about 0.5 g) was added, and the mixture was stirred at room temperature at 200 rpm for about 10 minutes.

  Aluminum nitrate nonahydrate (manufactured by Nacalai Tesque) was added in an amount of Al nitrate: Si atomic weight = 70: 30 (mol) of aluminum nitrate, and stirred at 200 rpm at room temperature for about 10 minutes.

  Thereafter, using a hot stirrer set at 60 ° C., the solution was stirred at a low speed until water evaporated, and then dried for a whole day and night in a 120 ° C. dryer (Air atmosphere).

  The obtained powder was pulverized in an agate mortar for about 5 minutes, and the pulverized powder was baked in a 400 ° C. electric furnace (Air atmosphere) for 4 hours. Further, the obtained powder was pulverized in an agate mortar for about 5 minutes to obtain a catalyst.

For acidic silica, a temperature-desorption method measuring device (Temperature-Programmed Desorption: TPD) is used to adsorb ammonia, which is a base probe molecule, to acidic silica support (SiO ₂ ), and then the catalyst temperature is raised to 100 ° C. Those having an acidic property in which the amount of ammonia desorbed up to ˜550 ° C. was 0.65 mmol / g per weight of acidic silica support were used.
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 23]
1 g of the catalyst obtained in Example 8 was put into 150 cc to 200 cc of ion exchange water, and stirred at room temperature at 200 rpm for about 10 minutes.

  Iron nitrate (III) 9 hydrate (manufactured by Nacalai Tesque) is added in an amount of aluminum nitrate such as Al atomic weight: Si atomic weight: Fe atomic weight = 95: 5: 1 (mol), and about 10 minutes at 200 rpm at room temperature. Stir.

  Thereafter, the solution was stirred using a hot stirrer set to 80 ° C. until the water evaporated, and then dried in a 120 ° C. dryer (Air atmosphere) for a whole day and night.

The obtained powder was pulverized in an agate mortar for about 5 minutes, and the pulverized powder was baked in a 500 ° C. electric furnace (Air atmosphere) for 2 hours. Furthermore, after the obtained powder was returned to room temperature, it was ground in an agate mortar for about 5 minutes to obtain a catalyst.
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 24]
A catalyst was obtained in the same manner as in Example 23 except that Al atomic weight: Si atomic weight: Fe atomic weight of aluminum nitrate = 90: 10: 1 (mol).
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 25]
A catalyst was obtained in the same manner as in Example 23 except that Al atomic weight: Si atomic weight: Fe atomic weight of aluminum nitrate = 80: 20: 1 (mol).
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 26]
A catalyst was obtained in the same manner as in Example 23 except that Al atomic weight: Si atomic weight: Fe atomic weight of aluminum nitrate = 70: 30: 1 (mol).
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 27]
A catalyst was obtained in the same manner as in Example 23 except that Al atom weight of aluminum nitrate: Si atom weight: Fe atomic weight = 70: 30: 1 (mol), and calcined at 700 ° C.
A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

[Example 28]
A catalyst was obtained in the same manner as in Example 23 except that Al atom weight of aluminum nitrate: Si atom weight: Fe atomic weight = 70: 30: 1 (mol), and calcined at 400 ° C.

  A gas phase reaction was performed under the conditions shown in Table 2 using the obtained catalyst.

  The reaction conditions and results for Examples 22-28 are shown in Table 2.

  From FIG. 11, when a catalyst (Examples 23 to 26) further containing an oxide of Fe in γ-alumina and acidic silica was used, a catalyst not containing the corresponding oxide of Fe (Examples 8 to 10). It can be seen that the phenol yield is improved as compared with (22) and (22).

  From FIG. 12, when yielding 30% acidic silica (Examples 26-28), the yield of phenol was most improved when calcined at 500 ° C. This is presumably because, when calcination is performed at 500 ° C., the iron oxide is sufficiently activated and the activity does not decrease due to the collapse of the pores on the surface of γ-alumina and acidic silica.

  Since the method of the present invention can be carried out at low cost and simply, it can be preferably applied to the production of aromatic compounds such as catechol and phenol, which are useful chemical substances, from lignin on an industrial scale.

Claims (9)

A method for producing phenol , wherein a mixture containing guaiacol as a main component is subjected to demethylation or demethoxylation reaction in the gas phase in the presence of a catalyst containing γ-alumina in a form supported on the surface of acidic silica. ,
The above method, wherein the molar ratio between the Al atomic weight of γ-alumina and the Si atomic weight derived from acidic silica is 97: 3 to 60:40 .   The method of claim 1, wherein the catalyst further comprises an oxide of at least one metal selected from the group consisting of Ag, Zr and Ni. The method of claim 1, wherein the catalyst further comprises an oxide of at least one metal selected from the group consisting of Ag and Zr. The method according to any one of claims 1 to 3 , wherein the catalyst further comprises an oxide of Fe. Guaiacol mixtures is guaiacol containing as a main component, The method according to any one of claims 1-4. A catalyst for demethylation or demethoxylation reaction in a gas phase of a mixture containing guaiacol as a main component, comprising γ-alumina in a form supported on an acidic silica surface ,
The catalyst as described above, wherein the molar ratio between the Al atomic weight of γ-alumina and the Si atomic weight derived from acidic silica is 97: 3 to 60:40 . The catalyst according to claim 6 , further comprising an oxide of at least one metal selected from the group consisting of Ag, Zr and Ni. The catalyst according to claim 6, further comprising an oxide of at least one metal selected from the group consisting of Ag and Zr. The catalyst according to claim 7 or 8 , further comprising an oxide of Fe.

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