Woody biomass decomposition apparatus, and method for producing a reaction mixture containing cellulose, hemicellulose decomposition products, and lignin decomposition products using the same.

Abstract

To provide a woody biomass decomposition apparatus capable of continuously separating large quantities of woody biomass into useful components under mild conditions, and a method for producing a reaction mixture containing cellulose, hemicellulose decomposition products, and lignin decomposition products using the same. [Solution] The woody biomass decomposition apparatus of the present invention comprises a hopper for containing a butanol phase containing woody biomass, a heating section for heating a mixture of the butanol phase supplied from the hopper and a separately supplied aqueous phase containing maleic acid, and a reactor for reacting the mixture supplied from the heating section to obtain a reaction mixture, arranged from upstream to downstream. Here, the heating section is capable of heating the mixture to a temperature above the upper critical temperature of butanol and water.

Description

Technical Field

[0001] The present invention relates to a lignocellulosic biomass decomposition apparatus and a method for producing a reaction mixture containing cellulose, hemicellulose decomposition products, and lignin decomposition products using the same.

Background Art

[0002] In recent years, efforts towards carbon neutrality have been actively pursued as a means to address environmental changes caused by greenhouse gas emissions. Among these efforts, research on alcohol fermentation using lignocellulosic biomass has also been progressing (Patent Document 1).

[0003] In addition, a large amount of lignin decomposition products are generated as by-products during alcohol fermentation, and research on the utilization of these lignin decomposition products has also been underway. Initially, lignin decomposition products were mainly used as fuel, but in recent years, they have also attracted attention as raw materials for polymer compounds (Patent Document 2).

[0004] When lignin is used as a raw material for polymer compounds, the quality of lignin may deteriorate due to alteration depending on the separation method. Therefore, a method for producing lignin decomposition products using phase separation has been proposed as a method that can be separated under relatively mild conditions (Patent Document 3). In the above conventional technology, lignocellulosic biomass is processed by a batch method, but for processing a large amount of lignocellulosic biomass, it is desirable to process it continuously. However, if the above conventional technology is directly applied to a continuous process, the intermediate processed product will decompose into an aqueous phase, an aliphatic alcohol phase, and a solid phase during transportation, and cannot be transported uniformly, and the process cannot proceed appropriately.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

[0006] The present invention aims to solve the above-mentioned problems, and its objective is to provide a woody biomass decomposition apparatus that can continuously separate large amounts of woody biomass into useful components under mild conditions, and a method for producing a reaction mixture containing cellulose, hemicellulose decomposition products, and lignin decomposition products using the same. [Means for solving the problem]

[0007] The present invention relates to a woody biomass decomposition apparatus, A hopper containing the butanol phase which includes the woody biomass, A heating section that heats a mixture of the butanol phase supplied from the hopper and an aqueous phase containing maleic acid supplied separately. A reactor for reacting the mixture supplied from the heating section to obtain a reaction mixture, It is provided along the upstream to downstream, The heating unit is capable of heating the mixture to a temperature above the upper critical temperature of butanol and water.

[0008] In one embodiment, the inside of the heating section can be heated to a temperature above the upper critical temperature, ranging from 125°C to 230°C.

[0009] In one embodiment, pumps for controlling the flow of the mixture are located upstream of the heating section and downstream of the reactor.

[0010] In one embodiment, the reaction mixture contains cellulose, hemicellulose hydrolysates, and lignin hydrolysates.

[0011] The present invention also relates to a method for producing a reaction mixture from woody biomass, comprising cellulose, hemicellulose degradation products, and lignin degradation products. A step in which a mixture of a butanol phase supplied from a hopper and a separately supplied aqueous phase containing maleic acid is introduced into the heating section of the above-mentioned woody biomass decomposition apparatus at a temperature above the upper critical temperature of butanol and water. A step of supplying the mixture from the heating section to the reactor and reacting it to obtain a reaction mixture containing cellulose, hemicellulose hydrolysates, and lignin hydrolysates. This method includes [something]. [Effects of the Invention]

[0012] The woody biomass decomposition apparatus of the present invention allows for the continuous separation of large quantities of woody biomass into cellulose, hemicellulose decomposition products, and lignin decomposition products. This facilitates mass production. Furthermore, because the obtained cellulose, hemicellulose decomposition products, and lignin decomposition products are separated under mild conditions, they can be used for various purposes, such as alcohol fermentation and as materials for synthetic resins, thereby contributing to the promotion of carbon neutrality. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing an example of the woody biomass decomposition apparatus of the present invention. [Figure 2] This is a schematic diagram showing another example of the woody biomass decomposition apparatus of the present invention. [Figure 3] This is a schematic diagram showing yet another example of the woody biomass decomposition apparatus of the present invention. [Figure 4] This flowchart illustrates an example of a procedure for isolating each component from the reaction mixture obtained by the present invention. [Figure 5] This graph shows the results of measuring the weight-average molecular weight (Mw) of dried lignin, solid lignin, and water-soluble lignin obtained in Example 2 using the GPC method. [Figure 6]A graph showing the results of thermomechanical analysis of the dried lignin and solid lignin obtained in Example 2. [Figure 7] A graph showing the results of thermomechanical analysis of the dried lignin and solid lignin obtained in Example 3.

Embodiments for Carrying Out the Invention

[0014] The present invention will be described with reference to the accompanying drawings. In all the following drawings, components having the same reference numerals are the same as those shown in other drawings.

[0015] FIG. 1 is a schematic diagram showing an example of the lignocellulosic biomass decomposition apparatus of the present invention.

[0016] The lignocellulosic biomass decomposition apparatus 100 of the present invention shown in FIG. 1 includes a hopper 110, a heating unit 120, and a reactor 130.

[0017] The hopper 110 serves to store the butanol phase in which the lignocellulosic biomass 102 is dispersed in butanol and supply it to the heating unit 120. It has an inlet (not shown) through which butanol or a medium containing butanol can be continuously or intermittently supplied, an inlet 112 into which the lignocellulosic biomass 102 is introduced, and an outlet 114 for sending out the butanol phase in which the lignocellulosic biomass 102 is dispersed in butanol to the heating unit 120. The outlet 114 of the hopper 110 is connected to a pipe 116, and the above-mentioned butanol phase can be supplied to the heating unit 120 described later.

[0018] Examples of the lignocellulosic biomass 102 include EFB (empty fruit bunches of palm coconuts), bagasse, wood chips such as cedar sawdust, thinned wood, waste wood, wooden construction waste, rice straw, and combinations thereof. The form of the lignocellulosic biomass 102 may be, for example, a powder adjusted to a predetermined size by sieving, a chip, or wood chips generated in the construction or lumbering process.

[0019] The concentration of woody biomass in the butanol phase is not particularly limited, but is preferably 100 g / L to 400 g / L, more preferably 150 g / L to 300 g / L. If the concentration of woody biomass in the butanol phase is less than 100 g / L, the amount of woody biomass in the apparatus may be too small, making steady operation of the apparatus difficult. If the concentration of woody biomass in the butanol phase exceeds 400 g / L, the woody biomass may clog the pipes in the apparatus, causing blockage. Examples of butanol that constitute the butanol phase include n-butanol (n-butyl alcohol) and tert-butyl alcohol. In this invention, n-butanol is preferred because it is a liquid at room temperature and can form two phases in the presence of water.

[0020] The heating unit 120 plays the role of mixing and heating the butanol phase discharged from the hopper 110 with a separately prepared aqueous phase. The heating unit 120 can heat the mixture of the butanol phase and the aqueous phase to a temperature above the upper critical temperature of the butanol and water contained therein. The heating unit 120 can heat its interior to a temperature preferably of 125°C to 230°C, more preferably of 170°C to 200°C.

[0021] The heating unit 120 is not particularly limited as long as it can raise the temperature of the butanol phase and the aqueous phase to the above heating temperature in a closed space, for example, but examples include a heat transfer medium type mixing tank in which a separately heated heat transfer medium is filled into an airtight jacket surrounding a pipe that transports a mixture of the aqueous phase and the butanol phase, and an electric heating type mixing tank that is heated by an electric heater.

[0022] The aqueous phase contains maleic acid. The concentration of maleic acid constituting the aqueous phase is not particularly limited as long as it is sufficient to adequately decompose the woody biomass contained in the butanol phase, but is preferably 0.05 mol / L to 0.2 mol / L, and more preferably 0.08 mol / L to 0.15 mol / L. If the concentration of maleic acid constituting the aqueous phase is below 0.05 mol / L, the woody biomass decomposition ability of the resulting aqueous phase may decrease. If the concentration of maleic acid constituting the aqueous phase is above 0.2 mol / L, the decomposition products obtained from the woody biomass may be further decomposed. Examples of water that can be used to constitute the aqueous phase include ion-exchanged water, pure water, distilled water, RO water, and tap water.

[0023] The aqueous phase is pre-contained in the reservoir 140. In the woody biomass decomposition apparatus 100 shown in Figure 1, the aqueous phase is sent to the heating section 120 by a pump 150 located downstream of the pipe 142 connected to the reservoir 140. The pump 150 is not particularly limited, but examples include a mono pump, an internal gear pump, etc. Since the aqueous phase passing through the pipe 142 is a single phase that does not contain the butanol phase, it can be easily sent by the pump 150 even at low temperatures.

[0024] The reactor 130 is located downstream of the heating section 120 and is connected to the heating section 120 via a pipe 122. The mixture of the aqueous phase and the butanol phase heated in the heating section 120 is supplied to the reactor 130 via the pipe 122.

[0025] The reactor 130 plays the role of retaining the mixture of the aqueous phase and the butanol phase for a predetermined time and decomposing the woody biomass in the butanol phase in the presence of maleic acid contained in the aqueous phase. In the woody biomass decomposition apparatus 100 of the present invention, it is preferable that the reactor 130 has a pipe-like shape in order to enable the continuous decomposition of woody biomass 102. That is, by flowing the above mixture at a predetermined flow rate in a pipe-shaped reactor 130 having a predetermined length, the mixture can be retained in the reactor 130 for a predetermined time. While the mixture is retained in the reactor 130, the temperature inside the reactor 130 is preferably maintained at a temperature above the upper critical temperature of butanol and water, more preferably 125°C to 230°C, and even more preferably 180°C to 200°C. Furthermore, the fluidity of the mixture inside the reactor 130 is controlled so that the mixture is retained inside the reactor 130 for preferably 30 minutes to 180 minutes, more preferably 50 minutes to 120 minutes.

[0026] As a result, the mixture of butanol and water, heated above its upper critical temperature in the upstream heating section 120, reacts in the reactor 130, causing the woody biomass 102 to decompose and generate a reaction mixture. The reaction mixture is then removed from the system, for example, through a pipe 132 located downstream of the reactor 130.

[0027] The reaction mixture obtained in this way contains, for example, cellulose, hemicellulose decomposition products, and lignin decomposition products derived from woody biomass, and can be separated into its respective components, as described later.

[0028] Figure 2 is a schematic diagram showing another example of the woody biomass decomposition apparatus of the present invention.

[0029] As shown in Figure 2, in the woody biomass decomposition apparatus 200 of the present invention, pumps 160 and 170 are located upstream of the heating section 120 and downstream of the reactor 130, respectively, to control the flow of the mixture of the aqueous phase and the butanol phase.

[0030] The types of pumps 160 and 170 are not particularly limited as long as they can deliver slurry liquid, but examples include mono pumps and internal gear pumps. It is preferable that pump 160 can adjust the delivery pressure to a high level in order to raise the heating section 120 above the upper critical temperature, for example, one that can increase the pressure to about 2 MPa.

[0031] The pump 170, located downstream of the reactor 130, is for discharging the reaction mixture obtained from the decomposition of woody biomass. When the reaction mixture in reactor 130 is at a temperature above the upper critical temperature of water and butanol, the water and butanol remaining in the reaction mixture are miscible and exist in a mixed state. Therefore, it can be easily discharged from the system using a normal pump.

[0032] However, in the woody biomass decomposition apparatus 200 shown in Figure 2, the contents contained in the heating section 120 and reactor 130 (for example, a mixture of the aqueous phase and the butanol phase or the reaction mixture) have a temperature of, for example, 125°C or higher (above the upper critical temperature of water and butanol). Therefore, directly discharging the resulting reaction mixture from the pump 170 may worsen work efficiency from a safety management perspective. For this reason, as in the woody biomass decomposition apparatus 300 shown in Figure 3, a cooler 180 and a receiver 190 can be provided downstream of the reactor 130.

[0033] In the woody biomass decomposition apparatus 300 shown in Figure 3, the reaction mixture is cooled in the cooler 180 upstream of the pump 170 and recovered in the receiver 190. Therefore, concerns about high-temperature reaction mixture being discharged from the pump 170 can be avoided.

[0034] However, in the embodiment shown in Figure 3, the temperature of the reaction mixture passing through the cooler 180 falls below the upper critical temperature of the water and butanol mixture. In this regard, the present invention may, in order to prevent the reaction mixture from separating into an aqueous phase and a butanol phase and hindering its discharge by the pump 170, place a stirring blade (not shown) inside the cooler 180 and / or between the cooler 180 and the receiver 190 to assist in the discharge of the reaction mixture. As a result, even if the reaction mixture that has passed through the cooler 180 separates into an aqueous phase and a butanol phase, the aqueous phase and the butanol phase in the reaction mixture will be sufficiently dispersed through the rotation of the stirring blade and can be discharged out of the system more safely via the pump 170.

[0035] Thus, according to the woody biomass decomposition apparatus of the present invention, woody biomass can be decomposed to obtain a reaction mixture containing cellulose, hemicellulose decomposition products, and lignin decomposition products. These cellulose, hemicellulose decomposition products, and lignin decomposition products can be separated according to the flowchart shown in Figure 4, for example, to isolate each component.

[0036] Referring to Figure 4, the reaction mixture obtained by the woody biomass decomposition apparatus of the present invention is a mixture containing a solid phase, an aqueous phase, and a butanol phase. The solid phase can be separated, for example, by filtration 402. The method and filter media used for filtration 402 are not particularly limited, as long as both the solid phase and the filtrate can be extracted for use. Examples of materials constituting the filter media include stainless steel, cellulose, glass fiber, fluorofiber, and cellulose acetate. Filtration 402 can be arbitrarily selected by those skilled in the art, such as natural filtration, vacuum filtration, or pressure filtration.

[0037] The filtration 402 separates the reaction mixture into a filtrate containing the aqueous phase and the butanol phase, and a residue containing a solid phase (mainly cellulose). The resulting solid phase can be purified and / or washed using means known in the art as needed, and finally the cellulose can be isolated.

[0038] Next, the filtrate obtained by filtration 402 can be separated into an aqueous phase and a butanol phase by decantation 404, for example, as shown in Figure 4. Specifically, by allowing the filtrate to stand in a predetermined container for a predetermined time, it is separated into a butanol phase which constitutes the supernatant and an aqueous phase which becomes the lower phase. Alternatively, the separation of the butanol phase and the aqueous phase may be performed by centrifugation instead of standing. After that, by taking out only the supernatant through decantation 404, the aqueous phase can be obtained as a residue. Since this aqueous phase contains water-soluble lignocellulose, the lignocellulose can finally be isolated by removing the solvent water from this aqueous phase.

[0039] On the other hand, the butanol phase of the supernatant contains lipid-soluble lignin degradation products. Therefore, after removing the butanol solvent from the supernatant 406 to obtain dry lignin, water is added to it, and it is stirred and filtered 408 to obtain a solid residue and further filtrate. Then, solid lignin can be obtained by purifying and washing the solid residue, and water-soluble lignin can be obtained by removing the water contained in the filtrate.

[0040] The lignin decomposition product obtained in this way can be used as a desired polymer composition by, for example, mixing it with a thermoplastic resin. Furthermore, the softening temperature of this lignin decomposition product can be adjusted by adding separately obtained water-soluble lignin. As a result, by adjusting the amount of water-soluble lignin added so that the softening temperature is equivalent to that of the coexisting thermoplastic resin, a polymer composition with the same handling properties as that of the thermoplastic resin alone can be obtained. [Examples]

[0041] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples.

[0042] (Example 1: Fabrication of a woody biomass decomposition device) The woody biomass decomposition device 300 shown in Figure 3 was manufactured as follows.

[0043] A pipe 116 was directly connected to the outlet 114 of a hopper 110 with a capacity of approximately 100 liters and an internal stirring blade. A mono pump (6NHLS10PUNX, manufactured by Hyoshin Equipment Co., Ltd.; discharge pressure set to 2 MPa during use) was connected to the other end as a pump 160. Further downstream of the pump 160, a stainless steel pipe with a diameter of 20A (27.2 mm) and a length of 2000 mm was attached as a heating section 120. A heating device (EvaCon unit, manufactured by Kansai Chemical Machinery Manufacturing Co., Ltd.) equipped with an airtight jacket through which the heat source circulated was placed around the outer circumference of the stainless steel pipe. This heating section 120 was capable of raising the temperature of a mixture of woody biomass slurry and maleic acid aqueous solution to 190°C.

[0044] In addition, a 20-liter reservoir 140 (a container made of high-density polyethylene (HDPE)) capable of holding a maleic acid aqueous solution was connected to a pump 150 (FXM1-02-STST-UWS manufactured by Takumina Co., Ltd.) via a pipe 142, and the downstream end of the pump 150 was connected to the heating unit 120 so that the maleic acid aqueous solution could be sent to the heating unit 120.

[0045] Furthermore, downstream of the heating section 120, a SUS304 pipe (60.5 mm in diameter, 3280 mm in length; the mixture can pass through the inside in approximately 30 minutes) with its outer circumference covered with insulation material was placed as a reactor 130. Downstream of the reactor 130, a cooling pipe 180 with an internal stirring blade was placed, and a receiver 190 located downstream of it was connected. Downstream of the receiver 190, a pump 170 (6NE10PA manufactured by Hyoshin Equipment Co., Ltd.) was connected. In this way, the woody biomass decomposition apparatus 300 shown in Figure 3 was constructed.

[0046] (Example 2: Decomposition of EFB (empty fruit clusters of palm kernels)) First, 1 kg of EFB (empty palm fruit clusters) with a particle size of 0.3 mm was added to 3.3 liters of n-butanol and stirred to obtain a slurry. This slurry was then placed into hopper 110 of the woody biomass decomposition apparatus 300 prepared in Example 1.

[0047] On the other hand, maleic acid was added to 10 liters of distilled water to prepare an aqueous maleic acid solution with a concentration of 0.086 mol / liter (10 g / L), which was then placed in the reservoir 140 of the woody biomass decomposition apparatus 300 prepared in Example 1.

[0048] Next, pumps 150 and 160 were operated to combine the slurry in hopper 110 and the maleic acid aqueous solution in reservoir 140 in the heating section 120 to obtain a mixture. The temperature inside the heating section 120 was adjusted to 180°C and pressurized to 1.2 MPa. Pump 160 was then operated to supply the mixture from the heating section 120 to reactor 130, and the mixture was passed through reactor 130 for 36 minutes while maintaining a temperature of 180°C to promote the decomposition of EFB contained in the mixture. After that, the mixture was cooled to approximately 40°C in cooler 180, and 29.5 kg of the reaction mixture (S1) was recovered in receiver 190.

[0049] The resulting reaction mixture (S1) was filtered according to the flowchart in Figure 4 (using No. 2 filter paper manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate. This filtrate was allowed to stand for 24 hours, and the supernatant was removed by decantation to obtain the butanol phase. Next, 0.26 kg of dried lignin was obtained by evaporating n-butanol from this butanol phase using a constant-temperature drying oven (SOFW-600SB manufactured by AS ONE Corporation).

[0050] The obtained dried lignin (0.5 g) was dissolved in 20 mL of acetone, then water (400 mL) was added and the mixture was stirred. The mixture was then filtered to obtain the residue and filtrate. The residue was dried to obtain 0.29 g of solid lignin. The filtrate was concentrated and dried to obtain 0.19 g of water-soluble lignin.

[0051] Subsequently, the weight-average molecular weight (Mw) of the dried lignin, solid lignin, and water-soluble lignin obtained above was determined by the GPC (gel permeation chromatography) method shown below. The results are shown in Figure 5.

[0052] (1) Method for preparing samples Each sample was dissolved in acetone, filtered, and the acetone was removed from the resulting filtrate. The sample solution was then prepared by dissolving the sample in tetrahydrofuran (THF). (2) Measuring device and standard sample The following was used: Equipment used: Waters Japan Ltd. e2695;2414RI Detector Standard sample: PSt Quick F

[0053] As shown in Figure 5, the dried lignin, solid lignin, and water-soluble lignin obtained above have different distribution curves, suggesting that the water-soluble lignin is a lignin monomer.

[0054] Furthermore, thermomechanical analysis (TMA) was performed on the dried lignin and solid lignin obtained above using a thermomechanical analyzer (TMA7100, Hitachi High-Tech Science Corporation). The results are shown in Figure 6.

[0055] As shown in Figure 6, the softening patterns of dried lignin and solid lignin were almost identical. Here, as is clear from the flowchart shown in Figure 4 and the separation operation described above, dried lignin itself contained both solid lignin and water-soluble lignin. However, as shown in Figure 6, the softening temperature of dried lignin was lower than that of solid lignin, indicating that the presence of water-soluble lignin (lignin monomer) in dried lignin lowers its softening temperature compared to solid lignin.

[0056] (Example 3: Decomposition of cedar wood powder) Reaction mixture (S2) was obtained using the above-mentioned woody biomass decomposition apparatus 300 in the same manner as in Example 2, except that cedar wood powder was used instead of EFB. Dry lignin, solid lignin, and water-soluble lignin were obtained in the same manner as in Example 2, except that this reaction mixture (S2) was used instead of reaction mixture (S1).

[0057] Next, thermomechanical analysis (TMA) was performed using the dried lignin and solid lignin obtained from the reaction mixture (S2) in the same manner as in Example 2. The results obtained are shown in Figure 7, superimposed on the EFB results described in Figure 6.

[0058] As shown in Figure 7, the dried lignin and solid lignin derived from cedar wood flour obtained in Example 3 had similar properties to the dried lignin and solid lignin derived from EFB obtained in Example 2. [Explanation of symbols]

[0059] 100, 200, 300 Wood Biomass Decomposition Equipment 102 Woody Biomass 110 Hopper 112 Inlet 114 Outlet 120 Heating section 130 Reactors 140 Reservoir 150, 160, 170 pumps 180 Cooler 190 Receiver

Claims

1. A woody biomass decomposition device, A hopper containing the butanol phase which includes the woody biomass, A heating section that heats a mixture of the butanol phase supplied from the hopper and an aqueous phase containing maleic acid supplied separately. A reactor for reacting the mixture supplied from the heating section to obtain a reaction mixture, It is provided along the upstream to downstream, An apparatus in which the heating section is capable of heating a mixture to a temperature above the upper critical temperature of butanol and water.

2. The woody biomass decomposition apparatus according to claim 1, wherein the inside of the heating section can be heated to a temperature above the upper critical temperature, from 125°C to 230°C.

3. The woody biomass decomposition apparatus according to claim 1, wherein pumps for controlling the flow of the mixture are arranged upstream of the heating section and downstream of the reactor.

4. The woody biomass decomposition apparatus according to claim 1, wherein the reaction mixture contains cellulose, hemicellulose decomposition products, and lignin decomposition products.

5. A method for producing a reaction mixture containing cellulose, hemicellulose degradation products, and lignin degradation products from woody biomass, A step of introducing a mixture of a butanol phase supplied from a hopper and an aqueous phase containing maleic acid supplied separately into the heating section of the woody biomass decomposition apparatus according to any one of claims 1 to 4, at a temperature above the upper critical temperature of butanol and water. A step of supplying the mixture from the heating section to the reactor and reacting it to obtain a reaction mixture containing cellulose, hemicellulose hydrolysates, and lignin hydrolysates. Methods that include...

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