JP2014037354A - Method for manufacturing phenol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a specified phenol from a material including lignin.SOLUTION: The method of the present invention for manufacturing a phenol includes a step of treating, by using a catalyst and water within a circulatory reaction vessel under the following conditions, a lignin decomposition product obtained by decomposing a material including lignin: condition 1: that the feeding quantitative ratio of water with respect to the lignin decomposition product (water (g/h)/raw ingredient (g/h)) be 1-20; condition 2: that the pressure be 0.2-30 MPa.

Description

  The present invention relates to a method for producing phenols using lignin or a lignin degradation product obtained by decomposing lignin in a lignin-containing material as a starting material.

  In recent years, bioethanol produced using carbon-neutral biomass has attracted attention as a new fuel due to increasing environmental problems. Until now, bioethanol has been mainly produced from raw materials that compete with food such as starch and sugar, and problems such as a decrease in the supply of these raw materials to food and a rise in prices have been pointed out. Therefore, at present, attention is being focused on a technology for producing ethanol from cellulosic biomass that does not compete with food.

  Examples of cellulosic biomass include palm palm trunks and bunches, bagasse, rice straw, straw, corn residues (corn stover, corn cob, corn hull), Jatropha seed coat and shell, wood chips, and the like. These all contain lignin in addition to cellulose and hemicellulose that can be converted to sugar.

Lignin is contained in a solid residue separated from cellulose and hemicellulose at the stage of saccharification treatment of the above-described raw material, which is a pretreatment for bioethanol production. This residue can be used as fuel as it is. However, when lignin is decomposed, a phenol derivative or the like can be obtained. Therefore, it is more valuable to expand the phenol derivative as a raw material to other chemical industrial products than to use this residue as a fuel.
Therefore, a method has been developed in which a lignin decomposition product is obtained by decomposing lignin, and a compound that can be used as a raw material for chemical industrial products is obtained using the obtained lignin decomposition product as a starting material.
As an example, in substances derived from lignin including compounds such as diphenyl ether, diphenylmethane, 2-benzyloxyphenol, guaiacol, acetophenone, 1-phenyl-1-propanol, an alkyl ether bond between two aromatics of the compound, aromatic A method for producing phenols by decomposing a methoxy group and a carbonyl group bonded to a ring using a specific catalyst is disclosed (see Non-Patent Document 1).
Also proposed is a method for producing phenol and cresol from lignin through a two-step reaction of solubilizing a material containing lignin and a catalytic decomposition reaction of a solubilized solution containing a solubilized lignin degradation product. (See Non-Patent Document 2).

Yoshikawa et al. Journal of the Japan Petroleum Institute, 53, (3), 178-183 (2010) Junya Yoshikawa et al., 2011, 41st Petroleum / Petrochemical Discussion Meeting, 2E08

However, in the method of contacting with the catalyst as described above, the lignin-derived material to be contacted with the catalyst or the solubilized solution of the lignin degradation product contains lignin with a very wide molecular weight distribution, and it is liquid alone. Some are solid.
As described above, in the methods disclosed in Non-Patent Documents 1 and 2, lignin having a relatively large molecular weight easily causes clogging of the catalyst and reduces the catalytic activity. Further, the polymerization until reaching the catalyst layer is promoted, and the amount of coke produced increases.
For this reason, the room for the further improvement was left in the method of manufacturing the compound which can become a raw material of a chemical industrial product further from the raw material containing a lignin.
Then, this invention makes it a subject to provide the method of manufacturing specific phenols from the material containing lignin.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by treating a lignin degradation product obtained from a lignin-containing material under specific conditions, and have completed the present invention. It was.

That is, the method for producing phenols according to the present invention includes a step of treating a lignin degradation product obtained by decomposing a material containing lignin using a catalyst and water under the following conditions using a flow reactor. Have.
Condition 1: Supply ratio of water and lignin degradation product (water (g / h) / raw material (g / h)) is 1 to 20
Condition 2: The pressure in the reactor is 0.2 to 30 MPa.

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing specific phenols from the material containing lignin can be provided.

It is a block diagram explaining the batch type reaction apparatus used by the Example and the comparative example. It is a block diagram explaining the flow-type reaction apparatus used by the Example and the comparative example.

[Method for producing phenols]
The method for producing phenols according to the embodiment of the present invention is a process of treating a lignin degradation product obtained by decomposing a material containing lignin using a catalyst and water under the following conditions using a flow reactor. Have
Condition 1: Supply ratio of water and lignin degradation product (water (g / h) / raw material (g / h)) is 1 to 20
Condition 2: The pressure in the reactor is 0.2 to 30 MPa.

In the method for producing phenols according to the present embodiment, it is preferable to treat the lignin degradation product under the following conditions in addition to the above conditions 1 and 2.
Condition 3: the temperature in the reactor is 300 to 500 ° C.
Condition 4: catalyst amount (g) / feed rate of lignin degradation product (g / h) is 0.1 to 10
In the said condition 3, it is preferable that the temperature in a reactor is set to 350-450 degreeC. Thereby, phenol and cresol are produced.

<Lignin-containing material>
Examples of the material containing lignin that can be used in the method for producing phenols according to the embodiment of the present invention include lignin-containing biomass and lignin-containing resin. Of these, lignin-containing biomass is preferred. Examples of the lignin-containing biomass include palm palm trunks / air bunch, bagasse, rice straw, straw, corn residues (corn stover, corn cob, corn hull), Jatropha seed coat / shell, wood chips and the like. The lignin content of these materials is about 15-40% by mass.
The lignin-containing biomass may be at least one selected from by-products obtained in the process of saccharifying cellulosic biomass and by-products obtained in the pulp manufacturing process, in addition to the above-described ones. Furthermore, examples of the lignin-containing biomass include those described above, saccharification residues obtained in the process of saccharifying cellulosic biomass, and black liquor obtained in the pulp manufacturing process. In the process of saccharifying cellulosic biomass, the remaining residue obtained by hydrolyzing cellulose and hemicellulose to extract sugar is a solid mainly composed of lignin. For this reason, this residue can be used as a lignin-containing material.

(Method for producing lignin degradation product)
The lignin degradation product obtained from the lignin-containing biomass is a treatment selected from the group including the organosolv method, the pressurized hydrothermal method, the steam explosion method, the ammonia treatment method, the oxidative decomposition method, and the microwave heating method. It is preferable to be obtained by a method.
The organosolv method is a method of treating lignin-containing biomass using an organic solvent under high temperature and high pressure.
The pressurized hot water method is a method for treating lignin-containing biomass in high-temperature, high-pressure water in a subcritical region near the critical point (374 ° C., 22 MPa).
The steam explosion method is a method in which steam is injected into a raw material lignin-containing biomass and the lignin-containing biomass is exploded by instantaneously releasing the pressure.
The ammonia treatment method is a method for treating lignin-containing biomass in the presence of heated and pressurized ammonia.
The oxidative decomposition method is a method of oxidatively decomposing lignin-containing biomass using an organic peroxide, hydrogen peroxide, oxygen, or the like as an oxidizing agent.
The microwave heating method is a method for thermally decomposing lignin-containing biomass using the heating of a substance by the interaction between the microwave and the substance.
In addition, as a decomposition method for obtaining a lignin decomposition product, for example, a general batch reactor, a semi-batch reactor, or the like can be used. Moreover, the system which reacts, extruding the slurry which consists of the material containing lignin, water, and alcohol with a screw or a pump etc. is also applicable. This method is a method having a decomposition step of treating a material containing lignin under the following conditions in a solvent containing water and alcohol.
Condition A: The mass ratio of the material and the solvent is 1 to 50% by mass. Condition B: The molar ratio of water to alcohol in the solvent is 1/1 to 20/1.

  In the present invention, by using a solvent containing water and alcohol, the carboxylic acid produced by the decomposition reaction of lignin and the alcohol react to produce an ester. The produced ester has the effect of inactivating a highly reactive and easily polymerized carboxylic acid.

  In the embodiment of the present invention, examples of the alcohol used as the solvent include linear alcohols such as methanol, ethanol, propanol, butanol, pentanol, and hexanol, and branched alcohols. The alcohol may be a polyhydric alcohol. Examples of water used for the solvent include tap water, industrial water, ion exchange water, and distilled water.

  The mass ratio of the material containing lignin and the solvent (including water and alcohol) is 1 to 50% by mass.

In the method for producing a lignin decomposition product according to the embodiment of the present invention, the following conditions may be set in addition to the conditions A and B in the decomposition step.
Condition C: temperature of the solvent is 150 to 400 ° C. Condition D: treatment time is 1 minute to 10 hours

  The lignin decomposition product manufactured by the manufacturing method of the lignin decomposition product demonstrated above is a compound which has the following structures, for example.

<Catalyst>
Catalysts that can be used in the method for producing phenols according to the embodiment of the present invention include iron hydroxide (FeOOH), triiron tetroxide (Fe ₃ O ₄ ), and diiron trioxide (Fe ₂ O ₃ ). It is preferable to use at least one iron-based catalyst as a main component.
Specific examples of suitable iron-based catalysts used in the present embodiment include a catalyst represented by the following formula (1).
CeO ₂ (a) / ZrO ₂ (b) / Al ₂ O ₃ (c) / FeO _x (1)
In formula (1), a, b, and c represent the content [% by mass] when Ce, Zr, and Al in the catalyst are assumed to be CeO ₂ , ZrO ₂ , and Al ₂ O ₃ , respectively. a is 0 to 15, b is 2 to 15, and c is 3 to 20. X represents the oxygen composition (ratio) of the iron oxide compound. As a, b, and c, a is preferably 0 to 6, b is 4 to 10, and c is more preferably 4 to 10.

The catalyst may contain at least one subcomponent of alumina, silica, titania, and magnesia in addition to the main constituent components. Further, the catalyst may contain at least one of zirconia and ceria in addition to the main component and subcomponents.
Specific examples of such a catalyst include FeOx—SiO ₂ —ZrO ₂ catalyst, FeOx—TiO ₂ —ZrO ₂ catalyst, FeOx—MgO—ZrO ₂ catalyst, FeOx—ZrO ₂ catalyst, FeOx—Al _2. Examples thereof include an O ₃ —ZrO ₂ catalyst. Of these, FeOx—ZrO ₂ -based catalysts and FeOx—Al ₂ O ₃ —ZrO ₂ -based catalysts are preferable, and CeO—ZrO ₂ —Al ₂ O ₃ —FeO _x is particularly preferable.

Examples of the compound produced by the above production method include phenols and catechols.
Phenols include phenol and cresol. Other phenols include alkylphenols excluding cresol. As alkylphenols, an alkyl group is a C2-C3 saturated or unsaturated hydrocarbon group, and includes linear and branched ones. Moreover, alkyloxyphenols are mentioned as phenols. Specific examples include methoxyphenol and ethoxyphenol. Examples of catechols include catechol and alkyl catechols.

<Each condition>
When the feed amount ratio of water and lignin decomposition product (water (g / h) / lignin decomposition product (g / h)) in condition 1 in the flow reactor is less than 1, the amount of coke produced increases. The yield of phenols decreases. On the other hand, if it exceeds 20, the reactivity is lowered and the yield of phenols is lowered. From the above viewpoint, the supply ratio of water and lignin degradation product (water (g / h) / lignin degradation product (g / h)) is preferably 2 to 10. More preferably, it is 2-7.5. Thereby, the yield of phenol and cresol can be increased.
Examples of water used in the method for producing phenols according to the embodiment of the present invention include tap water, industrial water, ion exchange water, and distilled water.
When the pressure in the reactor under condition 2 is less than 0.2 MPa, the polymerization until the catalyst layer is reached is promoted, the catalyst is easily clogged with the lignin decomposition product, the catalytic action is reduced, and phenols This leads to a decrease in yield. If it exceeds 30 MPa, the polymerization of the produced phenols is promoted, and the yield of phenols is reduced. From the above viewpoint, the pressure of Condition 2 is preferably set to 1 to 25 MPa. The pressure of condition 2 is more preferably 2 to 23 MPa, and further preferably 10 to 20 MPa. If it is this range, the yield of a phenol and a cresol can be raised.
When the temperature in the reactor of condition 3 is less than 300 ° C., the reactivity decreases, and when it exceeds 500 ° C., the lignin decomposition product is polymerized, and the amount of coke produced increases. From the above viewpoint, the temperature is more preferably 350 to 450 ° C.
When the amount of catalyst (g) / feed rate of lignin degradation product (g / h) in condition 4 is less than 0.1, the reactivity decreases, and when it exceeds 10, the lignin degradation product is polymerized and the amount of coke produced Will increase. From the above viewpoint, the catalyst amount (g) / lignin decomposition product supply rate (g / h) is more preferably 0.5 to 5.

  In the method for producing phenols according to the embodiment of the present invention, from the above viewpoint, the condition of the above step 1: the ratio of water and lignin degradation product (water (g / h) / raw material (g / h)) is 2 -10, Condition 2: The pressure in the reactor is set to 2 to 23 MPa, and Condition 3: The temperature in the reactor is set to 350 to 450 ° C. Can be manufactured.

  The phenol produced by the above production method can be used as a raw material such as phenol resin and polycarbonate. Cresol can be used as a raw material for pharmaceuticals, disinfectants, bactericides and the like. Alkylphenols other than those described above can be used as raw materials for nonionic surfactants (alkylphenol ethoxylates), raw materials for antioxidants for plastics, raw materials for stabilizers for vinyl chloride, and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.
[Examples and Comparative Examples]
<Example 1>
(Preparation of catalyst)
An aqueous solution of iron nitrate, zirconium oxynitrate, cerium nitrate, and aluminum nitrate was mixed and stirred for 30 minutes. Assuming that Fe, Zr, Ce, and Al became Fe ₂ O ₃ , ZrO ₂ , CeO ₂ , and Al ₂ O ₃ , the catalyst was 7.5% by mass of ZrO _{2 and} 2.5% by mass of CeO _2. %, Al ₂ O ₃ was adjusted to 7.0% by mass.
About 10% by mass of ammonia water was dropped with a microfeeder to neutralize to pH7. After neutralization, the mixture was stirred for 1 hour and filtered with suction. After suction filtration, the obtained solid was dried at 100 ° C. for 24 hours. After drying, the mixture was pulverized and calcined in air at 500 ° C. for 2 hours to obtain a CeO ₂ (2.5) -ZrO ₂ (7.5) -Al ₂ O ₃ (7.0) -FeO _x catalyst.
(Preparation of lignin degradation product)
Batch reaction of 0.7g of lignin (dealkaline lignin, manufactured by Tokyo Chemical Industry Co., Ltd.), 10.4 g of ion-exchanged water, and 10.6 g of 1-butanol (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) is shown in FIG. Put in the device. At this time, the molar ratio of water / 1-butanol was 4/1, and the total amount of the solvent was 21 g. After purging the inside of the reactor of the batch reactor with nitrogen, the temperature was raised to 350 ° C. and the reaction was carried out for 2 hours. The reaction time was the elapsed time after reaching the predetermined temperature. The temperature was measured with a thermocouple. After completion of the reaction, the reactor of the batch reactor was cooled, and after the temperature dropped to near room temperature, the entire contents of the reactor were taken out and filtered. The filtrate was separated into a 1-butanol phase and an aqueous phase. The 1-butanol phase contains lignin degradation products.

(Decomposition treatment of lignin degradation products using a flow reactor)
Subsequently, the above-prepared CeO ₂ (2.5) -ZrO ₂ (7.5) -Al ₂ O ₃ (7.0) -FeO _x catalyst was charged into the reactor of the flow reactor shown in FIG. did. Water and a 1-butanol phase containing a lignin decomposition product were supplied into the reactor, and catalytic cracking treatment with a catalyst was performed under the following conditions.
Supply ratio (water / lignin decomposition product-containing 1-butanol phase): 2.5
Reactor internal pressure: 15.0 MPa
Reactor temperature: 400 ° C
Catalyst amount (g) / Lignin degradation product supply rate (g / h): 0.5 h

(Yield calculation of phenols)
The yield of phenols in the component obtained by the decomposition treatment was calculated by the following formula.
Carbon yield of phenols (C-mol%) =
Carbon content in phenols (C-mol) / carbon content in lignin (C-mol) × 100

<Example 2>
The reaction was carried out under the same conditions as in Example 1 except that the reactor internal pressure was 2 MPa.
<Example 3>
The reaction was carried out under the same conditions as in Example 1 except that the reactor internal pressure was 5 MPa.
<Example 4>
The reaction was carried out under the same conditions as in Example 1 except that the reactor internal pressure was 23 MPa.

<Example 5>
The reaction was carried out under the same conditions as in Example 1 except that the supply amount ratio (water / lignin decomposition product-containing 1-butanol phase) was 5.0.
<Example 6>
The reaction was performed under the same conditions as in Example 1 except that the supply ratio (water / lignin decomposition product-containing 1-butanol phase) was 7.5.

<Comparative Example 1>
The reaction was carried out under the same conditions as in Example 1 except that the reactor internal pressure was 0.1 MPa (normal pressure).
<Reference Example 1>
The reference example is a lignin decomposition product before catalytic reaction by the flow reactor in Example 1.

[Evaluation results]
Table 1 shows the yields (C-mol%) of phenols obtained by the methods of Examples and Comparative Examples.

  As shown in Table 1, it was found that the yields of phenol, cresol and other alkylphenols were improved by increasing the pressure (2 to 23 MPa). Moreover, it turned out that the yield (selectivity) of a phenol and a cresol improves by raising the supply amount ratio (water / lignin decomposition product) of water and a lignin decomposition product.

Claims (9)

A method for producing phenols comprising a step of treating a lignin degradation product obtained by decomposing a material containing lignin under a condition described below with a flow reactor using a catalyst and water.
Condition 1: Supply ratio of water and lignin degradation product (water (g / h) / raw material (g / h)) is 1 to 20
Condition 2: The pressure in the reactor is 0.2 to 30 MPa. In condition 1, the supply ratio of water and lignin degradation product (water (g / h) / raw material (g / h)) is set to 2 to 10,
The method for producing phenols according to claim 1, wherein the pressure is set to 2 to 23 MPa under condition 2. The method for producing a phenol according to claim 1 or 2, wherein the lignin degradation product is further treated under the following conditions in addition to the above conditions 1 and 2.
Condition 3: the temperature in the reactor is 300 to 500 ° C.
Condition 4: catalyst amount (g) / feed rate of lignin degradation product (g / h) is 0.1 to 10   The method for producing phenols according to claim 3, wherein phenol and cresol are produced by setting the temperature in the reactor to 350 to 450 ° C under the condition 3.   The lignin-containing material is lignin-containing biomass, and the lignin-decomposed product includes organosolv, pressurized hot water, steam explosion, ammonia treatment method, oxidative decomposition, and microwave heating. The manufacturing method of the phenols in any one of Claims 1-4 obtained by the processing method selected from these.   The method for producing phenols according to any one of claims 1 to 5, wherein the catalyst comprises at least one iron-based catalyst of iron hydroxide, triiron tetroxide, and diiron trioxide as a main constituent component.   The method for producing phenols according to claim 6, wherein the catalyst contains at least one component of alumina, silica, titania, and magnesia in addition to the main constituent components.   The method for producing phenols according to claim 6 or 7, wherein the catalyst contains at least one component of zirconia and ceria in addition to the main constituent components.   The lignin according to any one of claims 1 to 8, wherein the lignin-containing biomass is at least one selected from a by-product obtained in the process of saccharifying cellulosic biomass and a by-product obtained in the pulp manufacturing process. A method for producing a decomposition product.