JP2018062492A - Method for producing phenols from lignin-containing biomass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: a phenol monomer, having high utility and comprising phenol (carbolic acid) without any substituent and methyl phenol (cresol) as principal components, cannot be obtained with high selectivity because a lignin decomposition product, obtained from a biomass comprising a lignin as a principal component, is a mixture of phenols which has a lignin oligomer and various substituents.SOLUTION: A biomass solution or slurry liquid comprising a lignin as a principal component is brought into coexistent contact with a hydrogenation catalyst; hydrogenation reaction is carried out at reaction temperature of 100-400°C within the range of hydrogen partial pressure of 0.0-10 MPaG, thereby obtaining, from a lignin component, a phenol monomer that comprises 50 mol% or more of phenol (carbolic acid) without any substituent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a phenolic monomer from a lignin component using lignin-containing biomass as a raw material.

  As a technique for effectively utilizing the lignin component in biomass, as shown in Patent Document 1, a cypress wood of coniferous tree is used as a raw material and mixed with phenols (for example, p-cresol) and an acid and allowed to react for a predetermined time. After centrifugation, there is a method of synthesizing a phenol derivative by separating into an aqueous phase, an organic phase, and an intermediate phase and obtaining a three-stage extraction process for the organic phase. In this method, a mixture in which lignin is dissolved using a phenol as a solvent is obtained.

  Patent Document 2 discloses a technique for recovering organic components using napier glass or bagasse as a raw material in the presence of a hydrogenation catalyst (Pd-supported carbon) at a hydrogen pressure of 5 MPaG and a temperature of 200 ° C. In this technique, a furan derivative derived from hemicellulose and a phenol derivative derived from lignin are obtained. The phenol derivative is a mixture of methoxyphenol, methylphenol, ethylphenol and the like.

  As methods for obtaining phenols from biomass containing lignin, there are methods disclosed in Patent Documents 3, 4, and 5. In the method shown in Patent Document 3, a lignin decomposition product is obtained by heat-treating woody biomass (cedar) in the presence of an acid catalyst in addition to a mixed solvent of toluene and methanol. It is a lignin oligomer.

The disclosed in Patent Document 4 method, de-alkaline lignin in water / 1-butanol mixed _solution, the reaction was carried out in the conditions of 15 MPaG, 400 ° C. in the presence of CeO ₂ -ZrO ₂ -Al2O 3 -FeO _x catalyst Phenol monomers mainly composed of phenol, cresol and other alkylphenols are obtained.

  In the method disclosed in Patent Document 5, a palm-derived raw material is mechanically pulverized to lower the molecular weight, and then pyrolyzed at 500 ° C. under a nitrogen stream to obtain a phenol (coal acid) having no substituent. ing.

JP 2011-256381 A JP 2014-196295 A JP, 2006-050200, A JP 2014-037354 A JP 2014-015432 A

  In the method shown in Patent Document 1, phenols (cresol) are used as a raw material solvent, and a lignin decomposition product is contained in the raw material solvent. It cannot be manufactured. Moreover, in the method shown in Patent Document 2, a hemicellulose-derived furan derivative and a lignin-derived phenol derivative are obtained. The phenol derivative is a mixture of methoxyphenol, methylphenol, ethylphenol, and the like. Almost no phenol (coal acid) is obtained. In the method shown in Patent Document 3, a lignin degradation product is obtained, but the main component obtained is a lignin oligomer, and almost no phenolic monomer is obtained. In the method shown in Patent Document 4, phenol monomers containing phenol, cresol, and other alkylphenols as main components are obtained, but the carbon yield of phenol (coal acid) having no substituent is as low as about 26 mol%. In the method shown in Patent Document 5, phenol (coal acid) having no substituent is obtained, but the yield is as low as about 2% by weight.

  As a result of intensive research while paying attention to the current state of the prior art, the present inventor brought a hydrogenation catalyst into coexisting contact with a biomass solution or slurry liquid containing lignin as a main component, and reduced the lignin component by a hydrogenation reaction. The inventors have found a production method for obtaining a phenol monomer containing 50 mol% or more of phenol (coal acid) having no substituent from the lignin component, and have completed the present invention.

  That is, the present invention relates to a method for producing a phenol (coal acid) having no substituent from a biomass mainly composed of lignin in a high yield.

In order to solve the above-mentioned problems, the first phenol production method uses a biomass solution or a slurry liquid containing lignin as a main component in a hydrogen partial pressure of 0.0 MPaG to 10 MPaG and a reaction temperature of 100 ° C. A hydrogenation reaction is carried out at ˜400 ° C. to obtain a phenol monomer containing 50 mol% or more of phenol (coal acid) having no substituent from the lignin component.
According to said structure, the phenolic monomer which has as a main component the phenol (coal acid) without a substituent with high utility value from biomass which has lignin as a main component can be obtained with a high yield.

In the second method for producing phenols, in order to solve the above-described problem, the phenol monomers obtained from the lignin component are phenol (carcoic acid) having no substituent, o-methylphenol (o-cresol), m- It is characterized by containing at least one of methylphenol (m-cresol) and catechol.
According to said structure, since the versatile phenolic monomer is obtained as a main component, the utility value of the obtained phenolic monomer is high.

The third method for producing phenols is characterized in that the biomass mainly composed of lignin is any one or more of woody, herbaceous, lignin by-products and waste biomass.
According to said structure, it becomes possible to utilize a wide range of biomass as a raw material, and can manufacture phenol using the biomass which can be procured.

In the fourth method for producing phenols, in order to solve the above-mentioned problems, the herbaceous material, which is a raw material of biomass mainly composed of lignin, is one or more of bamboo, napiergrass, rice straw, straw, and sugarcane bagasse. It is characterized by being.
According to said structure, since the lignin component from the herb to discard is utilized, the phenolic monomer which has a phenol (coal acid) as a main component can be obtained cheaply.

In the fifth method for producing phenols, in order to solve the above problems, the lignin by-product is any one of hot water extraction lignin, dilute sulfuric acid extraction lignin, soda pulp lignin, sulfite pulp lignin, and kraft pulp lignin. Or one or more.
According to said structure, since the raw material which has a benzene skeleton in the high concentration which is not reused as a waste material is used, the phenolic monomer which has phenol (coal acid) as a main component can be obtained in high yield at low cost. Can do.

The sixth method for producing phenols is characterized by continuously supplying a biomass solution or a slurry solution in order to solve the above problems.
According to said structure, since the biomass raw material is supplied continuously, the phenolic monomer which has a phenol (coal acid) as a main component can be obtained continuously, and it is suitable for the case of mass production.

In order to solve the above-mentioned problems, the seventh method for producing phenols is characterized in that the biomass solution or slurry liquid contains a hydrogenation catalyst containing at least one of palladium, platinum, and nickel.
According to the above configuration, since a metal having a high hydrogenation reaction activity is used, the hydrogenation reaction can proceed even at a low hydrogen partial pressure and a low reaction temperature, and phenol (coal acid is used under relatively mild conditions. ) Can be obtained as a main component.

The eighth method for producing phenols is characterized in that the biomass solution or slurry solution is strongly alkaline in order to solve the above problems.
According to said structure, a hydrogenation reaction can be accelerated | stimulated by the effect | action of a strong alkali, and the phenolic monomer which has a phenol (coal acid) as a main component can be obtained.

  Phenol based on phenol (carcoic acid), which has the most versatile and most useful value, and methylphenol (cresol), dimethylphenol (xylenol), and methoxyphenol (guaiacol), which are versatile and have high utility value Monomers can be obtained in high yield from biomass based on lignin.

GC-MS ion of the diethyl ether extract of Example 1 GC-MS spectrum of the diethyl ether extract of Example 3

  The method for producing phenols from lignin-containing biomass according to the present invention is a method of hydrogenating a biomass solution or slurry containing lignin as a main component at a hydrogen partial pressure of 0.0 MPaG to 10 MPaG and a reaction temperature of 100 ° C to 400 ° C. This is a method for obtaining a phenol monomer containing 50 mol% or more of phenol (coal acid) having no substituent from the lignin component by reaction.

  A biomass solution containing lignin as a main component is a solution in which lignin is dissolved in a solvent such as water. A biomass slurry containing lignin as a main component is a biomass containing lignin or lignin. A liquid dispersed in a solvent such as water. From the viewpoint of promoting the hydrogenolysis reaction, lignin is preferably a solution dissolved in a solvent.

  The solvent of the biomass solution or slurry solution containing lignin as a main component is not particularly limited, but it is preferable that the solvent is not hydrocracked in the hydrocracking reaction step, and examples thereof include saturated hydrocarbons, alcohols, and water. Examples of saturated hydrocarbons include hexane, cyclohexane, and heptane. Examples of alcohols include methanol, ethanol, propanol, butanol, ethylene glycol, and glycerin. From the viewpoint of being inexpensive and not hydrocracked, it is most preferable to use water as a solvent. In order to improve the solubility of lignin, saturated hydrocarbons, alcohols and the like exemplified in water may be mixed.

  Although the raw material biomass which manufactures the biomass solution or slurry liquid which has lignin as a main component will not be specifically limited if it is a biomass containing lignin, woody material, a herb, a lignin by-product, and a waste biomass can be illustrated. From the viewpoint of economically producing phenolic monomers, herbs having a utility value lower than that of wood are preferable, and it is particularly preferable to use lignin by-products processed as fuel or waste.

Examples of woody biomass include conifers such as red pine, black pine, cedar, cypress and fir, and broad-leaved trees such as wig, drill, zelkova and camphor.
Examples of herbaceous biomass include bamboo, napiergrass, rice straw, wheat straw, sugarcane bagasse and switchgrass.

  Examples of lignin by-products include hot water extraction lignin, dilute sulfuric acid extraction lignin, soda pulp lignin, sulfite pulp lignin, and kraft pulp lignin.

  Examples of the waste biomass include rice husk, pruning residue, construction waste wood, palm empty fruit bunch (EFB), palm coconut shell (PKS), and palm trunk.

  In order to make the lignin component into a solution or slurry, for woody biomass and herbaceous biomass, a method of forming an alkaline solution after thermal decomposition by pulverization after fine pulverization is exemplified. If it is a lignin by-product, it is already in solution or slurry, so there is no need to treat it, but it is particularly preferable to make an alkaline solution of 5 wt% to 20 wt% in order to completely dissolve the lignin component. .

  The reactor for hydrocracking is not particularly limited as long as it can maintain the hydrogen pressure and the vapor pressure of the solvent and can maintain the reaction temperature of several hundred degrees Celsius, but examples include a batch-type autoclave reactor and a continuous flow reactor. Can do.

  When hydrocracking in a batch type autoclave reactor, a predetermined amount of biomass solution or slurry solution containing lignin as a main component and reaction catalyst are charged into the reactor, and after the reactor is sealed, the space is replaced with hydrogen gas. Pressurize to a predetermined pressure. The stirring device provided in the reactor is started, the temperature of the solution or slurry liquid is raised to a predetermined temperature while stirring the solution or slurry liquid, and the temperature after the temperature rise is maintained for a predetermined time. The temperature of the slurry is cooled to room temperature to complete the reaction. When the reaction is carried out without containing a catalyst, only a predetermined amount of a biomass solution or slurry containing lignin as a main component is charged into the reactor, and the reaction is carried out in the same manner as when the reaction catalyst is contained.

  When hydrocracking in a continuous flow fluidized bed reactor, a reaction slurry liquid in which a reaction catalyst is dispersed in a biomass solution or slurry liquid mainly composed of lignin is used, and a pump capable of transferring the slurry is used. Feed to a continuous flow reactor. The reaction slurry is heated to a predetermined temperature by a heat exchanger and then supplied to the continuous flow reactor. The continuous flow reactor is supplied with hydrogen gas at a predetermined pressure by a compressor. The reaction slurry liquid and hydrogen gas supplied to the continuous flow reactor cause a hydrocracking reaction in the reactor. The reaction slurry liquid is cooled by a heat exchanger from the outlet of the continuous flow reactor, and then introduced into the gas-liquid separation tank to separate the gas component and the slurry liquid component. When the reaction is carried out without the catalyst, only the biomass solution or slurry liquid containing lignin as the main component is supplied to the continuous flow reactor using the pump, and the reaction is carried out in the same manner as when the reaction catalyst is contained. carry out.

  When hydrocracking is performed in a continuous flow fixed bed reactor, the biomass solution containing lignin as a main component is heated to a predetermined temperature in a heat exchanger and then the continuous flow fixed bed packed with a reaction catalyst. Introduced into the reactor. The continuous flow type fixed bed reactor is supplied with hydrogen gas at a predetermined pressure by a compressor. In the fixed bed reactor, gas (hydrogen gas), biomass solution (liquid), and catalyst (solid) coexist. The reaction liquid is cooled by a heat exchanger from the outlet of the continuous flow reactor, and then introduced into the gas-liquid separation tank to separate the gas component and the slurry liquid component. When the reaction is carried out without containing a catalyst, the reaction is carried out in the same manner as when the reaction catalyst is contained, using a continuous flow fixed bed reactor filled with a filler such as alumina instead of the reaction catalyst.

  The hydrogen partial pressure at the start of the reaction to obtain the phenolic monomer is selected in the range of 0.0 MPaG to 10 MPaG, but from the viewpoint of economics of the production equipment, it is preferably 0.0 MPaG to 1 MPaG, which is a low pressure, Further, it is particularly preferably 0.1 MPaG to 0.2 MPaG. Here, the hydrogen partial pressure at the start of the reaction of 0.0 MPaG does not mean that the hydrogen partial pressure at the time of the reaction is 0.0 MPaG, but the hydrocracking reaction is performed in a closed system. Therefore, it is not denied that hydrogen generated by the decomposition reaction exists in the gas phase.

  The reaction temperature for hydrocracking is selected in the range of 100 ° C to 400 ° C, but is preferably 200 ° C to 300 ° C from the viewpoint of the balance between the reaction time and the total reaction pressure.

  The reaction time for hydrocracking is selected in the range of 1 min or more in the case of a batch reaction, but is preferably 5 min to 240 min from the economical viewpoint and the carbon yield of phenols, and more preferably 30 min to 120 min is particularly preferable.

  Although the hydrogenation catalyst used for reaction will not be specifically limited if it is a catalyst which accelerates | stimulates a hydrogenation reaction, The carbon catalyst, alumina catalyst, zeolite catalyst etc. which carry | supported Pd, Pt, and Ni as an active metal are illustrated.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these.

[Bamboo lignin preparation example]
Add 1.2 kg of bamboo powder to 6 kg of tap water in a stainless steel container, raise the temperature to 100 ° C., hold for 20 minutes with stirring, cool to room temperature, and use a Teflon (registered trademark) resin net (hole diameter: 10 mm). The solid was collected by filtration and washed with about 10 kg of tap water. The filtered solid content and 6 kg of tap water were charged into an autoclave, heated to 180 ° C. in a closed system, and maintained at 180 ° C. for 30 min. Then, when it cooled to room temperature and returned to normal pressure, it filtered with the net | network (hole diameter 10mm) made from a Teflon (trademark) resin, collect | recovered solid content, and wash | cleaned with 10 kg of tap water. A solid content of about 1 kg was charged with 160 g of 48 wt% sodium hydroxide solution and 6 kg of tap water in a stainless steel container, heated to 100 ° C., and maintained at 100 ° C. with stirring for 30 min. Then, when it cooled to room temperature and returned to the normal pressure, it filtered with the net | network (hole diameter 10mm) made from a Teflon (trademark) resin, and isolate | separated solid content. The filtered liquid (lignin solution) was heated to 70 ° C., and 250 g of 20 wt% hydrochloric acid was added and stirred. The neutralized and precipitated lignin solid matter was filtered through a cloth net to collect the solid content, and washed with about 10 kg of tap water. The washed lignin solid was dried at 100 ° C. for 24 hours to obtain 200 g of bamboo lignin powder (30 mesh under).

[Carbon content of lignin]
The amount of carbon in the entire reaction system was analyzed using a fully automatic elemental analyzer (PE-2400II (CHNS / O) manufactured by PerkinElmer). In the case of bamboo lignin, the carbon content was 63.08 wt%. As a result, the carbon amount in 0.5 g of bamboo lignin charged into the reaction system was calculated to be 0.3154 g.

[Amount of phenols]
After the hydrogenolysis reaction, the liquid in the reaction vessel was collected, the stirring blade and the vessel wall surface were washed with distilled water, and added to the reaction solution. The reaction catalyst was separated from the reaction solution using filter paper, and hydrochloric acid was added to the filtrate to make it weakly acidic. The reaction solution made weakly acidic and diethyl ether are mixed to transfer the organic component to the diethyl ether phase. To the diethyl ether extract, p-bromotoluene was added as an internal standard substance (IS) to prepare a sample for mass spectrometry. By analysis using a GC-MS apparatus (Shimadzu Corporation, GCMS-QP2010 SE), the number of moles of each phenol was calculated from the area ratio to the internal standard substance. Moreover, the molar selectivity of each phenolic monomer was computed from the total molar amount of the obtained phenolic monomer.

[Carbon yield of phenols]
For phenols with no substituents (coal acid), draw a calibration curve based on the standard, calculate the amount of phenol contained in the diethyl ether extract, and calculate the total phenols from the selectivity for phenols with no substituents (coal acid). The amount of carbon was calculated and divided by the weight of carbon contained in the reaction system to calculate the phenolic carbon yield after the reaction.

[Example 1]
0.5 g of bamboo lignin obtained in the preparation example of bamboo lignin, 20 ml (24.8 g) of 20 wt% NaOH aqueous solution and 1.5 g of 5 wt% Pd-supported activated carbon catalyst as a hydrogenation catalyst (water content is 55%, Wako Pure Chemical Industries, Ltd.) Made in a 100 ml autoclave, the space was replaced with hydrogen gas, and then pressurized with hydrogen gas to 1.0 MPaG. The inner solution was stirred at 410 rpm with a stirrer (TYPE PSM-004C01F pressure glass glass industry), pressurized to about 300 min at about 90 min, and held at about 300 ° C. for 60 min. The total pressure during this reaction was up to 2.2 MPaG. After completion of the reaction, the reaction solution is cooled to room temperature, purged with hydrogen gas and returned to normal pressure, and then the reaction catalyst is rotated for 10 minutes with a centrifuge (215 × 10G, Tommy Seiko LC-200) to produce a reaction. The product solution was recovered. Based on the method of calculating the amount of phenols and the carbon yield of the phenols, the carbon yield of phenols is 4.3%, the selectivity of phenol (coal acid) without substituents is 70.1 mol%, the selectivity of o-cresol is 2.4 mol %, M-cresol selectivity 9.2 mol%, catechol selectivity 13.7 mol%. FIG. 1 shows a GC-MS ion chromatograph of the diethyl ether extract of this example.

[Example 2]
A lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the hydrogen partial pressure at the start of the reaction was 0.5 MPaG. The phenols carbon yield was 4.7%, and there was no substituent phenol (coal acid). Of 95.4 mol%, o-cresol selectivity of 1.4 mol%, and m-cresol selectivity of 3.2 mol% were obtained.

Example 3
A lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the hydrogen partial pressure at the start of the reaction was changed to 0.2 MPaG, and the phenol carbon yield was 5.7%, and there was no substituent phenol (coal acid). The selectivity was 89.0 mol%, the o-cresol selectivity was 2.0 mol%, and the m-cresol selectivity was 9.0 mol%. The GC-MS ion chromatogram of the diethyl ether extract of a present Example is shown in FIG.

Example 4
The lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the hydrogen partial pressure at the start of the reaction was 0.0 MPaG (1 MPaG pressurization with argon gas), and the phenolic carbon yield was 1.9%. The selectivity for phenol (coal acid) having no substituent was 98.2 mol%, and the selectivity for o-cresol was 1.8 mol%.

Table 1 below shows the influence of the hydrogen partial pressure at the start of the reactions in Examples 1 to 4 using bamboo ligne as a raw material. A moderate hydrogen partial pressure improves the carbon yield and the selectivity of phenol (coal acid) without substituents.

Example 5
A lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that 1.0 g of a 5 wt% Pd-supported activated carbon catalyst was used as the hydrogenation catalyst. The phenol carbon yield was 4.0% and there was no substituent. The selectivity of phenol (coal acid) was 72.2 mol%, o-cresol selectivity was 2.0 mol%, m-cresol selectivity was 10.2 mol%, and catechol selectivity was 13.5 mol%.

Example 6
A lignin hydrocracking reaction was performed in the same manner as in Example 1 except that 0.5 g of a 5 wt% Pd-supported activated carbon catalyst was used as the hydrogenation catalyst, and the phenolic carbon yield was 4.3% and there was no substituent. The selectivity for phenol (coal acid) was 57.6 mol%, o-cresol selectivity was 2.0 mol%, m-cresol selectivity was 10.6 mol%, and catechol selectivity was 19.5 mol%.

Example 7
A lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that 0.25 g of a 5 wt% Pd-supported activated carbon catalyst was used as the hydrogenation catalyst, and the phenolic carbon yield was 4.2% and there was no substituent. The selectivity of phenol (coal acid) was 67.7 mol%, o-cresol selectivity was 2.0 mol%, m-cresol selectivity was 7.3 mol%, and catechol selectivity was 14.3 mol%.

Example 8
A lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the 5% by weight Pd-supported activated carbon catalyst was not added as a hydrogenation catalyst, a phenolic carbon yield of 3.7%, and a phenol having no substituent. (Carboxylic acid) selectivity of 73.7 mol%, o-cresol selectivity of 1.6 mol%, m-cresol selectivity of 6.7 mol%, and catechol selectivity of 8.7 mol% were obtained.

Table 2 below shows the influence of the hydrogenation catalyst addition amount in Example 1 and Examples 5 to 7 using bamboo ligne as a raw material. The addition of a hydrogenation catalyst improves the phenolic carbon yield.

Example 9
The hydrogenolysis reaction of lignin was carried out in the same manner as in Example 1 except that the hydrogenation reaction time was 120 min. The phenol carbon yield was 3.5%, and the selectivity for phenol (coal acid) having no substituent was 100 mol%. Got.

Example 10
The lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the hydrogenation reaction time was 30 min. The phenols carbon yield was 4.9%, and the selectivity for phenol (coal acid) with no substituent was 59. 6 mol%, o-cresol selectivity 3.3 mol%, m-cresol selectivity 9.3 mol%, and catechol selectivity 19.0 mol% were obtained.

Table 3 below shows the influence of hydrocracking reaction time of Example 1 and Examples 9 and 10 using bamboo lignin as a raw material. Increasing the hydrocracking time improves the selectivity for phenol (coal acid) without substituents.

Example 11
The lignin hydrocracking reaction was carried out in the same manner as in Example 1 except that the alkali addition amount was changed to 5% by weight. The phenol carbon yield was 32.3%, and the selectivity for phenol (coal acid) having no substituent was 69. 0.5 mol%, o-cresol selectivity 5.9 mol%, m-cresol selectivity 17.1 mol% were obtained.

Table 4 below shows the influence of the alkali concentration of Example 1 and Example 11 using bamboo ligne as a raw material.

Example 12
The hydrogenolysis reaction of lignin was carried out in the same manner as in Example 3 except that the active metal of the hydrogenation catalyst was Pt. The phenol carbon yield was 4.4% and the selectivity for phenol (coal acid) having no substituents. 80.0 mol%, o-cresol selectivity 12.5 mol%, m-cresol selectivity 3.2 mol% were obtained.

[Comparative Example 1]
The lignin hydrocracking reaction was performed in the same manner as in Example 3 except that the active metal of the hydrogenation catalyst was Ru. However, almost all of the lignin was gasified, and the phenolic carbon yield was 0%. .

Table 5 below shows the influence of the catalyst metal species of Example 3 and Example 12 and Comparative Example 1 on bamboo ligne. When the catalyst metal is Ru, lignin is gasified and phenols cannot be obtained.

Example 13
A lignin hydrocracking reaction was performed in the same manner as in Example 3 except that the lignin raw material was the reagent lignin (purchased from Tokyo Chemical Industry Co., Ltd.). (Carboxylic acid) selectivity 54.8 mol%, o-cresol selectivity 3.9 mol%, m-cresol selectivity 14.3 mol%, catechol selectivity 27.0 mol% were obtained.

Table 6 below shows the influence of the lignin raw material species of Example 3 and Example 13. When the catalyst metal is Ru, lignin is gasified and phenols cannot be obtained. Reagent lignin is poor in phenolic carbonization yield and selectivity for phenols without substituents over bamboo lignin.

High-yield phenolic monomers based on phenol (coal acid), methylphenol (cresol), dimethylphenol (xylenol), and methoxyphenol (guaiacol), which have high substituents, can be obtained in high yields. It can be expected as a phenol production process that replaces chemical processes.

Claims (8)

Phenol (carcoic acid) having no substituent from the lignin component by hydrogenating a biomass solution or slurry containing lignin as a main component at a hydrogen partial pressure of 0.0 MPaG to 10 MPaG and a reaction temperature of 100 ° C to 400 ° C. A method for producing phenols from lignin-containing biomass, wherein a phenol monomer containing 50 mol% or more is obtained. The phenolic monomer obtained from the lignin component contains at least one of o-methylphenol (o-cresol), m-methylphenol (m-cresol), and catechol in addition to phenol (carcoic acid) having no substituent. The method for producing a phenol according to claim 1. The method for producing phenols according to claim 1 or 2, wherein the biomass containing lignin as a main component is any one or more of woody materials, herbs, lignin by-products and waste biomass. The said herbaceous material is any one or more of bamboo, napier grass, rice straw, wheat straw, and sugarcane bagasse, The manufacturing method of the phenols of Claim 3 characterized by the above-mentioned. The phenols according to claim 3, wherein the lignin by-product is one or more of hot water extraction lignin, dilute sulfuric acid extraction lignin, soda pulp lignin, sulfite pulp lignin, and kraft pulp lignin. Manufacturing method. The said biomass solution or slurry liquid is supplied continuously, The manufacturing method of the phenols in any one of Claims 1-5 characterized by the above-mentioned. The method for producing phenols according to any one of claims 1 to 6, wherein the biomass solution or slurry solution contains a hydrogenation catalyst containing at least one of palladium, platinum, and nickel. The method for producing phenols according to any one of claims 1 to 7, wherein the biomass solution or slurry is strongly alkaline.