JP6779096B2 - How to make lignophenol - Google Patents

Description

The present invention relates to a method for producing lignophenol.

Conventionally, the following method has been adopted as a method for producing lignophenol from a lignocellulosic material containing lignin and cellulose.
That is, first, by mixing a lignocellulosic material, a phenol derivative, and an acid, lignin is reacted with a phenol derivative under an acid catalyst to produce lignophenol, and a mixture containing the lignophenol is obtained (mixing). Process).
Then, by allowing the mixture to stand, it is separated into an oil layer (a layer containing a phenol derivative, lignophenol, etc.) and an aqueous layer (a layer containing water, acid, saccharides, etc.) (static separation step).
Next, lignophenol is taken out from the oil layer.

However, the conventional method has a problem that it takes a long time to sufficiently separate the mixture into an oil layer and an aqueous layer in the static separation step.

From such a problem, a method using n-hexane has been proposed in order to shorten the time required for the static separation step. Specifically, the first mixture, which is the mixture, and n-hexane are mixed to obtain a second mixture, and the second mixture is allowed to stand to allow an oil layer (phenol derivative, lignophenol, n-hexane). A method for separating into an aqueous layer (a layer containing water, acid, sugar, etc.) and an aqueous layer (for example, Patent Document 1) has been proposed.

Japanese Unexamined Patent Publication No. 2013-208108

According to the method described in Patent Document 1, n-hexane can facilitate the static separation of the second mixture into the oil layer and the aqueous layer. As a result, the time required for the static separation step can be shortened. That is, according to the method described in Patent Document 1, the time required for producing lignophenol can be shortened.

However, as long as the lignophenol is separated from the mixture containing lignophenol by the static separation step, it is possible to avoid taking a time for sufficiently separating the mixture into an oil layer and an aqueous layer, that is, a standing time. Absent. Therefore, a separation step capable of separating lignophenol more efficiently while avoiding the standing time is desirable. That is, a method for producing lignophenol is desirable, which can further shorten the production time by further shortening the time for separating lignophenol.

Further, it is desirable that lignophenol having a small amount of impurities, that is, having high purity can be produced.

In view of such circumstances, it is an object of the present invention to provide a method for producing lignophenol, which can further shorten the production time of lignophenol and can obtain lignophenol with high purity.

As a result of diligent studies by the present inventor, the following was found and the present invention was conceived.
That is, in a mixture containing water, lignophenol, and a solvent (for example, n-hexane) that is a poor solvent for the lignophenol, the lignophenol becomes an agglomerate having adhesiveness. Therefore, even if the mixture is not sufficiently separated into an aqueous layer and an oil layer by static separation, the mixture is filtered, or in addition to filtration, an aggregate of lignophenol is attached to the carrier, and the mixture is said to be attached. The present inventor has found that by trapping lignophenol aggregates with a carrier, the liquid contained in the mixture can be separated into lignophenol aggregates.
In addition, the present inventor has found that by washing the agglomerates of lignophenol obtained by filtration or trapping and filtering with water, lignophenol having less impurities, that is, having high purity can be obtained. ..
As a result, the present inventor has found that the production time of lignophenol can be shortened and that lignophenol with high purity can be produced.

That is, the method for producing lignophenol according to the present invention is a method for producing lignophenol, which produces lignophenol from a lignocellulosic material.
A first mixing step of obtaining a first mixture by mixing the lignocellulosic material, a phenol derivative, and an acid.
A second mixing step of mixing the first mixture and a solvent which is a poor solvent for lignophenol to aggregate the lignophenol to obtain a second mixture containing the agglomerates of lignophenol.
A filtration step of filtering an aggregate of the lignophenol from the second mixture by filtering the second mixture.
It comprises a washing step of washing the lignophenol agglomerates by adding water to the lignophenol agglomerates collected in the filtration step.

According to such a configuration, by filtering the agglomerates of the lignophenol, the liquid component contained in the second mixture and the agglomerates of the lignophenol can be separated.
As a result, it is not necessary to sufficiently separate the second mixture into the aqueous layer and the oil layer by standing, so that the time for separating the agglomerates of the lignophenol from the second mixture can be shortened. As a result, the time required for producing lignophenol can be shortened.
Further, when the collected lignophenol aggregates are washed with water, the acid contained in the lignophenol aggregates can be dissolved in water, so that a lignophenol aggregate having a small residual amount of acid can be obtained. be able to.
As a result, by washing the lignophenol aggregate with water, a lignophenol aggregate having less impurities can be obtained, so that a lignophenol having less impurities, that is, high purity can be obtained.
Further, when the aggregate of lignophenol is dissolved in a solvent after the washing step and the pH of the solvent is adjusted, the amount of the alkaline agent used can be reduced.
As a result, the production time of lignophenol can be shortened, and lignophenol with high purity can be produced.

In addition, in the above-mentioned method for producing lignophenol,
Prior to the filtration step, a lignophenol trapping step of capturing the lignophenol aggregates from the second mixture by adhering the lignophenol aggregates in the second mixture to the carrier is provided.
In the washing step, in addition to the agglomerates of the lignophenol filtered in the filtration step, the agglomerates of the lignophenol trapped in the carrier in the lignophenol trapping step may be washed with the water. Good.

According to such a configuration, at least a part of the sticky lignophenol aggregate can be captured by the carrier before the filtration step, so that the amount of lignophenol deposited on the filtration surface in the filtration step is reduced. Can be made to.
As a result, the effect of clogging the filtration surface can be mitigated by the agglomerates of the sticky lignophenol, so that the decrease in filtration efficiency can be suppressed.
In addition, lignophenol can be obtained from agglomerates of lignophenol whose impurities have been reduced by washing.

In addition, in the above-mentioned method for producing lignophenol,
The lignophenol trapping step and the filtration step may be performed in one tank.

According to such a configuration, the lignophenol trapping step and the filtration step can be performed at the same time.
As a result, in addition to being able to improve the yield of lignophenol, the lignophenol trapping step and the filtration step can be efficiently performed.
In addition, the number of equipment required for producing lignophenol can be reduced.

As described above, according to the present invention, there is provided a method for producing lignophenol, which can further shorten the production time of lignophenol and can obtain lignophenol with high purity.

The schematic diagram of the lignophenol production apparatus which concerns on this embodiment, and the flow figure of the lignophenol production method which concerns on this embodiment. The schematic diagram of the lignophenol production apparatus which concerns on this embodiment. The figure which shows the example of the formation reaction of lignophenol.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The method for producing lignophenol according to the present embodiment is a method for producing lignophenol from a lignocellulosic material.

More specifically, the method for producing lignophenol according to the present embodiment includes a first mixing step of obtaining a first mixture by mixing the lignocellulose-based material, a phenol derivative, and an acid, the first mixture, and ligno. A second mixing step of aggregating lignophenol by mixing a solvent that is a poor solvent for phenol to obtain a second mixture containing agglomerates of lignophenol, and filtering the second mixture. The lignophenol aggregates are washed by a filtration step of filtering out the lignophenol aggregates from the second mixture and by adding water to the lignophenol aggregates filtered out in the filtration step. It includes a cleaning process.

Further, in the method for producing lignophenol, the agglomerates of lignophenol in the second mixture are attached to a carrier before the filtration step to obtain the agglomerates of lignophenol from the second mixture. The lignophenol trapping step is provided, and in the washing step, in addition to the agglomerates of the lignophenol filtered by the water in the filtering step, the ligno trapped in the carrier in the lignophenol trapping step. Agglomerates of phenol may be washed.

Further, in the method for producing lignophenol, the lignophenol trapping step and the filtration step may be performed in one tank.

In the present specification, filtration means separating lignophenol using a filter medium that does not allow agglomerates of lignophenol to pass through.
Further, in the present specification, cleaning means moving impurities contained in agglomerates of lignophenol into a cleaning solution and removing impurities transferred to the cleaning solution so as not to move to agglomerates of lignophenol again. means.
Further, in the present specification, as the capture, for example, an embodiment of capturing the aggregate of lignophenol while securing the flow path of the aggregate of lignophenol can be mentioned.

The lignocellulosic material contains lignin and cellulose.
Examples of the lignocellulosic material include wood-based materials and vegetation materials. Examples of wood-based materials include conifers (pine, sugi, cypress, etc.), hardwoods (castanopsis, persimmon, cherry, etc.), tropical trees, and the like. As plant materials, kenaf, ramie (straw hemp), linen (linseed), abaca (manila hemp), heneken (sisal hemp), jute (yellow hemp), hemp (cannabis), palm, palm, kozo, straw (rice straw, straw) Etc.), bagasse, corn, etc. Lignocellulosic materials are used in various states such as powder and chips (waste wood scraps, etc.).

The lignin is a polymer compound having a phenylpropane unit (C6-C3 unit) as a basic skeleton, and the phenylpropane unit is randomly oxidatively polymerized by an enzyme. The lignin is a component constituting the plant cell wall, and is bound to cellulose or hemicellulose in the plant cell wall.

The phenol derivative is a compound having a phenol structure in the molecule. Examples of the phenol derivative include phenol, p (para) -cresol, m (meth) -cresol, o (ortho) -cresol, anisole, 2,4-dimethoxyphenol, 2,6-dimethoxyphenol, and 2,4-dimethyl. Phenol, 2,6-dimethylphenol, n (normal) -propylphenol, i (iso) -propylphenol, tert (tersary) -butylphenol, catechol, resorcinol, pyrogallol, fluoroglucolcinol, bisphenol, vanillin, silingol, At least one selected from the group consisting of quaigol, phenolic acid, and kumalic acid is preferred. As the phenol derivative, cresol is preferable, and p-cresol is particularly preferable.

Examples of the acid include inorganic acids and organic acids. Examples of the inorganic acid include sulfuric acid, phosphoric acid and hydrochloric acid. Examples of the organic acid include p-toluenesulfonic acid, trifluoroacetic acid, trichloroacetic acid, formic acid and the like.

The solvent that is poor with respect to the lignophenol is a solvent that reduces the solubility of the lignophenol by addition, and usually has hydrophobicity.
Examples of the solvent include ethers, esters, hydrocarbons and the like. Examples of the ether include asymmetric ether and symmetric ether, and more specifically, diisopropyl ether and diethyl ether. Examples of the ester include ethyl acetate. Examples of the hydrocarbon include cyclic hydrocarbons and linear hydrocarbons, and more specifically, hexane (n-hexane and the like), toluene, pentane (n-pentane and the like), heptane, octane, cyclohexane, decalin, and the like. Examples include benzene.
As the solvent, hydrocarbons are preferable, and n-hexane is more preferable.

As the carrier, any carrier can be used as long as it can adhere agglomerates of lignophenol and thereby can capture the agglomerates of lignophenol.
As the carrier, for example, a granular carrier, a fibrous carrier, a plate-shaped carrier, or the like can be used.

As the granular carrier, a solid carrier and a hollow carrier can be used. The granular carrier is spread and arranged on the bottom of the tank where the capture step is performed, for example. The granular carrier preferably has a maximum diameter of 1 mm to 25 mm.
When the particle size of the granular carrier is 1 mm to 25 mm, it is preferable to adjust the particle size by using a sieve having a mesh size of 1 mm and a sieve having a mesh size of 25 mm.

As the solid carrier, a plastic sintered resin molded product, alumina balls, silica gel, granulated charcoal, zeolite and the like can be used. As the solid carrier, a carrier having a size capable of securing a flow path for agglomerates of lignophenol when spread and arranged on the bottom of the tank can be used.
When a solid carrier is used, the lignophenol aggregates are trapped by adhering the lignophenol aggregates to the outer surface of the carrier.
The solid carrier is preferably arranged so as to have a predetermined height from the viewpoint of prolonging the contact time between the carrier and the lignophenol aggregate and increasing the trapping amount of the lignophenol aggregate. .. For example, it is preferable that they are stacked and arranged.

Raschig ring or the like can be used as the hollow carrier. The hollow carrier is preferably arranged so that the hollow portion is substantially parallel to the flow direction (that is, the direction of gravity) of the agglomerates of lignophenol before contact with the carrier. As the hollow carrier, a carrier having a hollow portion having a size capable of securing a flow path for agglomerates of lignophenol can be used. The hollow carrier preferably has a longest diameter of 4 mm to 26 mm in a cross section orthogonal to the axial direction.
When a hollow carrier is used, the lignophenol aggregates are captured by adhering the lignophenol aggregates to the inner surface (the surface on the hollow portion side) and the outer surface of the carrier.
The hollow portion has a length of 8 mm to 26 mm from the viewpoint of prolonging the contact time between the inner and outer surfaces of the carrier and the aggregates of lignophenol and increasing the amount of trapped aggregates of lignophenol. It is preferable that it is extended so as to have.

As the fibrous carrier, polytetrafluoroethylene (PTFE) fiber, polypropylene fiber, glass fiber, activated carbon fiber and the like can be used. The fibrous carrier may be used in a disjointed state, or may be spread in a film shape.
When a fibrous carrier is used, the lignophenol aggregates are trapped by adhering the lignophenol aggregates to the outer surface of the carrier.

When it is spread in a film shape and used, it is preferably arranged in a mesh shape so as to secure a flow path for agglomerates of lignophenol. The mesh spacing is preferably 0.1 mm to 1.0 mm.
When arranged in a mesh shape, the carriers may be laminated and arranged from the viewpoint of prolonging the contact time between the carrier and the lignophenol aggregate and increasing the amount of the lignophenol aggregate trapped. preferable. Examples of such a carrier include demista (registered trademark).

As the plate-shaped carrier, a punching sheet, a punching plate, or the like can be used. As the punching sheet and punching plate, those having a perforated portion penetrating in the thickness direction of the plate body and having a perforated portion having a size capable of securing a flow path for agglomerates of lignophenol can be used. The longest diameter of the perforated portion is preferably 0.05 mm to 1.0 mm. It is preferable that the punching sheet and the punching plate are laminated and arranged so that the plate surfaces are substantially orthogonal to the flow direction (that is, the direction of gravity) of the agglomerates of lignophenol before contacting the carrier. ..
When a punching sheet or punching plate is used, agglomerates of lignophenol are trapped by adhering agglomerates of lignophenol to the plate surface.
The longest diameter of the perforated portion can be measured by a scanning electron microscope (SEM). Specifically, an arbitrary cross section orthogonal to the thickness direction of the plate is imaged with a scanning electron microscope, and the longest diameter of the perforated portion in the captured image is measured.

Further, as the plate-shaped carrier, a plate-shaped porous sintered body or the like can be used. The plate-shaped porous sintered body is formed by sintering (fusing) only the vicinity of the surface of the raw material powder and leaving the voids existing between the raw material powders, so that the pores communicate in a three-dimensional network. have. As the lignophenol aggregates flow through the pores, the lignophenol aggregates are trapped. The pores preferably have a longest diameter of 0.1 mm to 0.2 mm in a cross section orthogonal to the flow direction of the lignophenol aggregates in the pores.
The longest diameter of the pores of the plate-shaped porous sintered body can be measured by a scanning electron microscope (SEM). Specifically, an arbitrary cross section orthogonal to the thickness direction of the plate-shaped porous sintered body is imaged with a scanning electron microscope, and the longest diameter of pores in the captured image is measured.
Further, the plate-shaped porous sintered body has a thickness of 1 mm to 20 mm from the viewpoint of prolonging the contact time between the sintered body and the agglomerates of lignophenol and increasing the amount of trapped agglomerates of lignophenol. It is preferable to have.

The material constituting the carrier is not particularly limited, but polypropylene (PP), polytetrafluoroethylene (PTFE), alumina, activated carbon, and silica gel are preferably used in consideration of resistance to acids, alkalis, and organic solvents. Examples of the carrier made of PP include a plastic sintered body resin molded body, and examples of the carrier made of PTFE a material include a plastic sintered body resin molded body, Rasichling, a punching sheet, PTFE fiber, and the like. Examples of the carrier made of the above material include alumina balls, and examples of the carrier made of the activated carbon material include granulated coal and activated carbon fiber.
Among these, when resistance to alkali is considered, PP, PTFE and alumina are preferably used as materials, and when resistance to alkali and acid is considered, PTFE and alumina are preferably used as materials, and alkali, acid and Considering the resistance to organic solvents, it is preferable to use PTFE as a material.

The method for producing lignophenol according to this embodiment is a method for producing lignophenol from a lignocellulosic material using the lignophenol production apparatus according to this embodiment.

The lignophenol production apparatus according to the present embodiment is an apparatus for producing lignophenol from a lignocellulosic material.
The lignophenol production apparatus according to the present embodiment obtains a first mixture by mixing a lignocellulose-based material, a phenol derivative, and an acid, and is a solvent that is poor against the first mixture and lignophenol. The mixture is provided with a mixing section for aggregating lignophenol to obtain a second mixture containing agglomerates of lignophenol, and a purification section for extracting lignophenol from the two mixture.
In addition, the purification unit captures the lignophenol aggregates from the second mixture by adhering the lignophenol aggregates in the second mixture to the carrier, and the lignophenol aggregates trapped in the carrier are used in the washing liquid. Wash and remove lignophenol from the washed lignophenol agglomerates.
Further, the purification unit filtered the second mixture to filter out the aggregates of lignophenol that could not be captured by the carrier, and the collected lignophenol aggregates were washed with a washing liquid and washed. Lignophenol is extracted from the aggregate of lignophenol.
Water is used as the cleaning liquid of the present embodiment.
In the following, the term solid-liquid separation may be used as a concept that includes both capture and filtration.

More specifically, as shown in FIGS. 1 and 2, the lignophenol production apparatus 1 according to the present embodiment includes a pretreatment section 2 for accommodating a phenol derivative C in a lignocellulose-based material A, and a phenol derivative C. A first mixture is obtained by mixing the lignocellulosic material A and the acid aqueous solution D, and the first mixture and the solvent F, which is a poor solvent for the lignophenol, are mixed. A mixing unit 3 for aggregating the lignophenol to obtain a second mixture containing the agglomerates of the lignophenol, and a purification unit 4 for obtaining the lignophenol from the second mixture.
Hereinafter, each process performed by the purification unit 4 may be collectively referred to as a purification process.

In the first mixing step, the pretreatment section 2 and the mixing section 3 are used.

The pretreatment unit 2 includes a tank 21, a stirring unit 22 for stirring the contents in the tank 21, and a heating unit 23 for heating the inside of the tank 21. In the pretreatment section 2, at least a part of the bottom portion 21a of the tank 21 is formed of a filter medium so that the contents in the tank 21 can be filtered. Therefore, the pretreatment unit 2 also functions as a filtration unit (first filtration unit). The tank 21 is formed in a tapered shape so as to taper downward. Examples of the pretreatment unit 2 include a “PV mixer with a filtration function” manufactured by Kobelco Eco-Solutions Co., Ltd.

In the first mixing step, the lignocellulosic material A and acetone B are mixed in the pretreatment section 2, and the lignocellulosic material A is degreased with acetone B (degreasing step a1). Acetone B is preferably added in an amount of 2 kg to 10 kg with respect to 1 kg of the lignocellulosic material A. Next, the mixture of the lignocellulosic material A and the acetone B is filtered to separate the solid lignocellulosic material A and the liquid acetone B, and the acetone B is recovered (first filtration step a2). ..
As a result, the fat contained in the lignocellulosic material A can be removed from the lignocellulosic material A by acetone B.
Further, in the first mixing step, after the first filtration step a2, the inside of the tank 21 is heated by the heating unit 23 to volatilize the acetone B adhering to the lignocellulosic material A, thereby causing the lignocellulose-based material. Excess acetone B can be removed from A.

Further, in the first mixing step, the lignocellulosic material A from which excess acetone B has been removed and the phenol derivative C are mixed in the pretreatment section 2, thereby accommodating the phenol derivative C to the lignocellulosic material A. (Acquisition step a3). The phenol derivative C is preferably added in an amount of 3 kg to 10 kg with respect to 1 kg of the lignocellulosic material A. Then, by filtering the mixture of the lignocellulosic material A and the phenol derivative C, the solid lignocellulosic material A and the excess liquid phenol derivative C are separated, and the phenol derivative C is recovered (second). Filtration step a4).
Further, in the first mixing step, after the second filtration step a4, the inside of the tank 21 is heated by the heating unit 23 to volatilize the phenol derivative C adhering to the lignocellulosic material A, and lignocellulose. Excess phenol derivative C can be removed from the system material A.
The lignocellulosic material A from which the excess phenol derivative C has been removed is transferred to the mixing unit 3 for further treatment.

The mixing unit 3 includes a tank 31 and a stirring unit 32 for stirring the contents in the tank 31. Since the acid aqueous solution D is added into the tank 31, the tank 31 and the stirring unit 32 are preferably glass-lined from the viewpoint of excellent acid resistance.

Further, in the first mixing step, the lignocellulose-based material A containing the phenol derivative C and the acid aqueous solution D are mixed in the mixing unit 3 to generate lignophenol, and the lignophenol is contained. 1 Mixture is obtained (generation step a5). The acid aqueous solution D is preferably added in an amount of 3 kg to 10 kg with respect to 1 kg of the lignocellulosic material A.
In the production step a5, the cellulose contained in the lignocellulosic material A is hydrolyzed under an acid catalyst to produce saccharides. Further, the lignin contained in the lignocellulosic material A is hydrolyzed under an acid catalyst to reduce the molecular weight. In addition, lignin reacts with phenol derivatives under acid catalyst to produce lignophenol. FIG. 3 shows an example of a reaction for producing lignophenol using sulfuric acid as an acid and p-cresol as a phenol derivative C. In addition, the produced lignophenol is hydrolyzed under an acid catalyst to reduce the molecular weight. From the above, the first mixture containing lignophenol is obtained.

The acid aqueous solution D usually contains 65 to 98% by mass, preferably 72 to 98% by mass of acid.

Further, in the first mixing step, the first mixture containing lignophenol and water E are mixed in the mixing unit 3 to dilute the first mixture and reduce the concentration of acid in the first mixture. The hydrolysis reaction is suppressed (dilution step a6). It is preferable to add water E in an amount such that the acid concentration is 60% by mass or less after the first mixture is diluted.

In the second mixing step, the first mixture diluted with water E and the solvent F, which is a poor solvent for lignophenol, are mixed in the mixing unit 3 to dissolve in the liquid in the first mixture. The lignophenol is precipitated, and the lignophenol is aggregated to obtain a sticky lignophenol aggregate. The solvent F is preferably added in an amount of 3 kg to 10 kg with respect to 1 kg of the lignocellulosic material A.
As a result, a second mixture containing agglomerates of lignophenol is obtained (second mixing step b).

In the purification step, the purification unit 4 is used to take out lignophenol from the oil-water mixture which is the second mixture. More specifically, by solid-liquid separation of the second mixture, agglomerates of lignophenol are taken out, the aggregates of lignophenol taken out are washed with a washing liquid, and lignophenol is washed from the agglomerates of lignophenol. Take out.

The purification unit 4 takes out the lignophenol aggregate by solid-liquid separation of the second mixture, cleans the extracted lignophenol aggregate with the cleaning liquid G, and cleans the lignophenol aggregate and the alcohol H. Is mixed with the solid-liquid separation unit 4a for dissolving lignophenol in alcohol H to obtain an LP (lignophenol) alcohol solution containing lignophenol and alcohol H, and the alkaline agent I in the LP alcohol solution. The pH adjusting unit 4b for adjusting the pH, the concentrating unit 4c for concentrating lignophenol by removing alcohol H from the LP alcohol solution, and the ligno by mixing the sodium chloride aqueous solution J with the concentrated LP alcohol solution. A crystallization section 4d for crystallizing phenol and an LP alcohol solution containing the crystallized lignophenol are filtered to obtain solid lignophenol in a second filtering section 4e and a second filtering section 4e. It is provided with a drying portion 4f for drying the solid lignophenol.

The solid-liquid separation unit 4a includes a tank 4a1 and a stirring unit 4a2 for stirring the contents in the tank 4a1. Further, the solid-liquid separation unit 4a filters the trapping means 4a3 for capturing the lignophenol aggregates in the second mixture and the liquid obtained when the lignophenol aggregates are captured by the trapping means 4a3. As a result, the filtration means 4a4 for obtaining an aggregate of lignophenol that could not be captured by the trapping means 4a3 is provided. Further, the solid-liquid separation unit 4a includes cleaning means 4a5 for cleaning the lignophenol aggregates captured by the trapping means 4a3 and the lignophenol aggregates filtered by the filtering means 4a4.
In the present embodiment, as shown in FIG. 2, the alumina balls are arranged so as to spread over the bottom 4a1a of the tank 4a1 to serve as the capturing means 4a3. As the alumina balls, those having a size capable of securing a flow path for agglomerates of lignophenol are arranged.
Further, in the present embodiment, as shown in FIG. 2, a filter medium is arranged between the bottom portion 4a1a of the tank 4a1 and the capturing means 4a3 to form the filtering means 4a4.
As the filtering means 4a4, at least a part of the bottom portion 4a1a of the tank 4a1 may be formed of a filter medium so that the contents in the tank 4a1 can be filtered. As at least a part of the bottom 4a1a of the tank 4a1 being formed of a filter medium, for example, a "filter dryer" manufactured by Kobelco Eco-Solutions Co., Ltd. can be used.
Further, in the present embodiment, as shown in FIG. 2, a shower nozzle as a cleaning means 4a5 is arranged on the top 4a1b of the tank 4a1. The shower nozzle is preferably arranged so that the injection surface faces the filtration surface. A cleaning liquid pressurized by a pump (not shown) is supplied to the shower nozzle, and the cleaning liquid is ejected from the shower nozzle to perform cleaning.

In the purification step, the trapping means 4a3 of the solid-liquid separation unit 4a captures the agglomerates of lignophenol in the second mixture, and the agglomerates of lignophenol that could not be captured by the trapping means 4a3 are filtered by the filtering means 4a4. By taking it out, agglomerates of lignophenol are taken out (solid-liquid separation step c1). The liquid separated in the solid-liquid separation step c1 contains an acid and an organic solvent. The liquid separated in the solid-liquid separation step c1 can be separated into the acid aqueous solution D and the solvent F and recovered by static separation or the like.

The filter medium used as the filtering means 4a4 in the solid-liquid separation step c1 is an alloy containing polypropylene, polytetrafluoroethylene (for example, Teflon (registered trademark)), nickel and molybdenum from the viewpoint of excellent corrosion resistance. (For example, Hastelloy®) is preferred, and polypropylene, an alloy containing nickel and molybdenum is particularly preferred.
The pore size of the filter medium is preferably 10 to 30 μm, and particularly preferably 20 μm, from the viewpoint of not allowing the agglomerates of lignophenol to pass through and shortening the filtration time.

Then, in the purification step, the aggregates of lignophenol captured by the trapping means 4a3 and the aggregates of lignophenol filtered by the filtering means 4a4 are washed with the cleaning liquid G using the cleaning means 4a5 (cleaning step c2). ).
More specifically, water is used as the cleaning liquid G to clean the lignophenol aggregates.
The amount of water used as the cleaning liquid G is preferably 1.0 kg to 10 kg with respect to 1 kg of the lignocellulosic material A.
By washing the lignophenol aggregates with water, the residual acid concentration in the purified lignophenol can be reduced.

Next, in the purification step, the lignophenol aggregate and the alcohol H washed with the cleaning liquid G are mixed in the solid-liquid separation unit 4a to dissolve the lignophenol in the alcohol H, and the lignophenol and the alcohol H are dissolved. To obtain an LP alcohol solution containing (dissolving step c3). As the alcohol H, methanol, ethanol or the like can be used. Alcohol H is preferably added in an amount of 1 kg to 10 kg with respect to 1 kg of the lignocellulosic material A.
Next, the solid matter (residue) is removed from the LP alcohol solution by filtering the LP alcohol solution (third filtration step c4).

The pH adjusting unit 4b includes a tank 4b1 and a stirring unit 4b2 for stirring the contents in the tank 4b1. The tank 4b1 is preferably glass-lined from the viewpoint of excellent acid resistance.

Further, in the purification step, the pH is adjusted by mixing the LP alcohol solution from which the solid content has been removed and the alkaline agent I in the pH adjusting unit 4b (pH adjusting step c5).
Even after the washing step c2, the pH of the LP alcohol solution is usually 1 or more and less than 2 because the acid remains in the aggregate of lignophenol.
In the pH adjusting step c5, it is preferable to neutralize this acid to bring the pH to 2 or more and 4 or less.
Examples of the alkaline agent I include magnesium hydroxide and sodium hydroxide.
Here, in the present embodiment, since the lignophenol aggregate is washed with the cleaning liquid G in the washing step c2, the amount of acid remaining in the lignophenol aggregate can be reduced. Therefore, the amount of the alkaline agent I used in the pH adjusting step c5 can be reduced.

The concentrating unit 4c includes a tank 4c1, a stirring unit 4c2 for stirring the contents in the tank 4c1, and a heating unit 4c3 for heating the inside of the tank 4c1.

In the purification step, the pH-adjusted LP alcohol solution is heated in the heating section 4c3 while stirring in the tank 4c1 (concentration step c6). As a result, the alcohol in the LP alcohol solution can be evaporated in the concentrating unit 4c. As a result, the lignophenol concentration of the LP alcohol solution can be increased, and the amount of the LP alcohol solution to be treated can be reduced. In addition, lignophenol can be crystallized.

The crystallization unit 4d includes a tank 4d1 and a stirring unit 4d2 for stirring the contents in the tank 4d1.

In the purification step, the lignophenol is crystallized by mixing the sodium chloride aqueous solution J with the LP alcohol solution in which the lignophenol is concentrated in the concentration step c6 in the crystallization section 4d (crystallization step c7).
Lignophenol is highly water-soluble because it has high protonity due to the OH group contained in the phenol skeleton. However, the aqueous solution of lignophenol becomes low in the presence of sodium chloride. That is, sodium chloride produces a salting out effect. As a result, when the sodium chloride aqueous solution J is mixed with the LP alcohol solution, lignophenol is crystallized.
The sodium chloride aqueous solution J preferably has a sodium chloride concentration of 0.1 to 5% by mass.
It is preferable to add 4 kg to 10 kg of the sodium chloride aqueous solution J with respect to 1 L of the alcohol H added to the solid-liquid separation unit 4a.

Further, in the purification step, a solid lignophenol is obtained by filtering the LP alcohol solution containing the crystallized lignophenol with the second filtration unit 4e (fourth filtration step c8). The filtrate obtained in the fourth filtration step c8 can be recovered as alcohol H.
Further, in the purification step, the lignophenol obtained in the second filtration section 4e is dried in the drying section 4f to obtain purified lignophenol K (drying step c9).

The purified lignophenol K has a residual acid concentration of preferably 1000 mg / kg or less, more preferably 500 mg / kg or less. The residual acid concentration can be measured by the electric capillary method.

The lignophenol K obtained by the method for producing lignophenol according to the present embodiment, that is, the purified lignophenol K can be used, for example, in applications such as flame retardants for plastics, plywood adhesives, and impregnating materials.

The reason why lignophenol is aggregated into agglomerates in the second mixture is as follows.
Phenols have a hydroxyl group, and this hydroxyl group acts as a proton donor and can cause a dissociation reaction in water. In addition, when phenols are dissociated, phenoxide ions are stabilized by resonance. From this, phenols have a certain degree of hydrophilicity.
Therefore, the structural part of phenols among lignophenols (see FIG. 3) has a certain degree of hydrophilicity.
Further, among lignophenols, the hydroxyl group portion other than the structural portion of phenols also has a certain degree of hydrophilicity.
On the other hand, lignophenol has a structural portion (a portion composed of a hydrocarbon such as a benzene ring) having an affinity for a solvent.
That is, lignophenol has a structural portion having a certain degree of hydrophilicity and a structural portion having an affinity for a solvent.
From this, when a solvent that is a poor solvent for lignophenol is mixed with lignophenol and water, the solvent that is a poor solvent for lignophenol repels the water and the repulsive water and lignophenol. On the other hand, the lignophenol molecule is oriented between the solvent which is a poor solvent and the solvent which is a poor solvent for lignophenol, and as a result, the lignophenol is poor for water and the lignophenol. It aggregates with the solvent that becomes the solvent.
In addition, the present inventor explains the reason why the lignophenol aggregate has adhesiveness because of the impurities contained in the lignophenol aggregate (for example, the reaction of loosening the lignocellulosic material (the reaction of loosening lignin and cellulose)). It is believed that this is due to the effects of (such as the sugar content that occurs).

The method for producing lignophenol according to the present invention is not limited to the above embodiment. Further, the action and effect produced by the method for producing lignophenol according to the present invention is not limited to the above-mentioned action and effect. The method for producing lignophenol according to the present invention can be variously modified without departing from the gist of the present invention.

Hereinafter, the present invention will be described in more detail with reference to examples. The following examples are for explaining the present invention in more detail, and do not limit the scope of the present invention.

[Example 1]
After degreasing the wood flour with acetone, cresol was added to the wood flour degreased with acetone (6 g of cresol per 1 g of wood flour), and the cresol was sufficiently absorbed in the wood flour.
Then, 120 g of an aqueous sulfuric acid solution (sulfuric acid: 72% by mass) was added to 30 g of wood powder to which cresol had been collected, and the mixture was vigorously stirred for 1 hour to obtain a first mixture.
Next, the first mixture and 180 g of water were stirred in a stirring tank for 15 minutes to stop the hydrolysis reaction with sulfuric acid.
Next, 120 g of hexane was added to the first mixture in which the hydrolysis reaction was stopped, and the mixture was vigorously stirred for about 1 hour to aggregate the lignophenol to obtain a second mixture containing the aggregate of the lignophenol.
Next, the second mixture was transferred to a filter (a filter having a scraper) by a screw type liquid feeder. Alumina balls having a diameter of 5 mm, which is a carrier, were spread on the bottom surface of the filter, and alumina balls having a diameter of 10 mm, which was also a carrier, were spread on the alumina balls having a diameter of 5 mm. In the filter, the aggregate of lignophenol is captured from the second mixture by the carrier, and the liquid content of the second mixture is filtered to filter the aggregate of lignophenol that could not be captured by the carrier. did. The time required for the capture and filtration was 1 hour.
The lignophenol aggregates obtained by capture and filtration were then washed with 30 g of water using a spray bottle. By mixing 55 g of methanol with the aggregate of lignophenol after washing, the lignophenol contained in the aggregate was dissolved in methanol to obtain an LP methanol solution containing lignophenol and methanol.
Next, the LP methanol solution was suction-filtered to remove solids (unreacted wood powder) from the LP methanol solution to obtain an LP methanol solution from which the unreacted substances had been removed.
Next, the pH of the LP methanol solution was adjusted to 3.0 by mixing powdered magnesium hydroxide with the LP methanol solution (pH 1).
Next, sulfate and excess magnesium hydroxide were removed from the LP methanol solution by suction filtration of the pH-adjusted LP methanol solution.
Then, 100 parts by mass of LP methanol solution from which sulfate and excess magnesium hydroxide were removed and 500 parts by mass of saline solution (saline concentration 5.0% by mass) were mixed to crystallize lignophenol.
Then, the LP methanol solution in which lignophenol was crystallized was suction-filtered with a 5C filter paper to obtain solid lignophenol.
Next, the lignophenol on the filter paper was dried by heating at 50 ° C. overnight to obtain purified lignophenol.
The sulfate ion concentration of the purified lignophenol was measured. Sulfate ion concentration was measured by the electric capillary method.
The sulfate ion concentration was 500 mg / kg.

[Comparative Example 1]
A second mixture was obtained in the same manner as in Example 1.
Next, the second mixture was allowed to stand and separate in the tank. By this static separation, the second mixture was separated into three layers: a hexane layer, a lignophenol layer (a layer of agglomerates of lignophenol), and a sulfuric acid layer. This static separation took a whole day and night.
Next, the hexane layer and the sulfuric acid layer were removed from the tank.
Next, by mixing methanol with the lignophenol layer remaining in the tank, lignophenol was dissolved in methanol to obtain an LP methanol solution containing lignophenol and methanol.
Next, the LP methanol solution was treated in the same manner as in Example 1 to obtain purified lignophenol.
The sulfate ion concentration of the lignophenol was 8000 mg / kg.

[Comparative Example 2]
A second mixture was obtained in the same manner as in Example 1 except that the amount of water added to the first mixture to stop hydrolysis was 180 g.
Next, the second mixture was transferred to the filter in the same manner as in Example 1. No carrier was placed in the filter. The solid lignophenol was filtered out by filtering the second mixture in the filter. The time required for filtration was 3 hours.
Next, in the same manner as in Example 1, by mixing methanol with solid lignophenol, the solid lignophenol was dissolved in methanol to obtain an LP methanol solution containing lignophenol and methanol.
Next, the LP methanol solution was treated in the same manner as in Example 1 to obtain purified lignophenol.
The sulfate ion concentration of the lignophenol was 6000 mg / kg.

From the above results, it was found that the method according to Example 1 can separate agglomerates of lignophenol from the mixture containing lignophenol in a shorter time than the methods according to Comparative Examples 1 and 2. That is, it was found that the method according to Example 1 can obtain lignophenol in a shorter time than the methods according to Comparative Examples 1 and 2.
Further, it was found that according to the method according to Example 1, lignophenol having a reduced value of sulfate ion concentration can be obtained as compared with the methods according to Comparative Examples 1 and 2.

1: Manufacturing equipment 2: Pretreatment part 3: Mixing part 4: Purification part,
4a: Solid-liquid separation part, 4a1: Tank, 4a1a: Bottom, 4a2: Stirring part, 4b: pH adjustment part, 4b1: Tank, 4b2: Stirring part, 4c: Concentrating part, 4c1: Tank, 4c2: Stirring part, 4c3 : Heating part, 4d: Crystallization part, 4d1: Tank, 4d2: Stirring part, 4e: Second filtration part, 4f: Drying part,
21: Tank, 21a: Bottom, 22: Stirring part, 23: Heating part, 31: Tank, 32: Stirring part,
A: Lignocellulose-based material, B: Acetone, C: Phenol derivative, D: Acid aqueous solution, E: Water, F: Solvent, G: Cleaning solution, H: Alcohol, I: Alkaline agent, J: Sodium chloride aqueous solution, K: Lignophenol,
a1: Degreasing step, a2: First filtration step, a3: Acquisition step, a4: Second filtration step, a5: Generation step, a6: Diluting step, b: Second mixing step, c1: Solid-liquid separation step, c2 : Cleaning step, c3: Dissolution step, c4: Third filtration step, c5: pH adjustment step, c6: Concentration step, c7: Crystallization step, c8: Fourth filtration step, c9: Drying step

Claims (4)

A method for producing lignophenol, which is a method for producing lignophenol from a lignocellulosic material.
A first mixing step of obtaining a first mixture by mixing the lignocellulosic material, a phenol derivative, and an acid.
A second mixing step of mixing the first mixture and a solvent which is a poor solvent for lignophenol to aggregate the lignophenol to obtain a second mixture containing the agglomerates of lignophenol.
A filtration step of filtering an aggregate of the lignophenol from the second mixture by filtering the second mixture.
A washing step of washing the lignophenol agglomerates by adding water to the lignophenol agglomerates collected in the filtration step is provided.
By performing the filtration step and the cleaning step in one tank, the cleaning step is carried out without taking out the aggregate of lignophenol from the tank.
A method for producing lignophenol. A method for producing lignophenol, which is a method for producing lignophenol from a lignocellulosic material.
A first mixing step of obtaining a first mixture by mixing the lignocellulosic material, a phenol derivative, and an acid.
A second mixing step of mixing the first mixture and a solvent which is a poor solvent for lignophenol to aggregate the lignophenol to obtain a second mixture containing the agglomerates of lignophenol.
A filtration step of filtering an aggregate of the lignophenol from the second mixture by filtering the second mixture.
Prior to the filtration step, a lignophenol trapping step of capturing the lignophenol aggregates from the second mixture by adhering the lignophenol aggregates in the second mixture to a carrier ,
The lignophenol aggregates are washed by adding water to the lignophenol aggregates filtered in the filtration step and the lignophenol aggregates trapped in the carrier in the lignophenol trapping step. Cleaning process and
With
The filtration step and the cleaning step are performed in one tank.
Manufacturing method of re-Diagnostics phenol. The lignophenol trapping step, the filtration step, and the cleaning step are performed in one tank.
The method for producing lignophenol according to claim 2. A dissolution step of mixing the washed agglomerates of the lignophenol with an alcohol and dissolving the lignophenol in the alcohol to obtain an alcohol solution containing the lignophenol.
A crystallization step of crystallizing lignophenol from the alcohol solution containing lignophenol.
The method for producing lignophenol according to any one of claims 1 to 3.

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