Method for hydropyrolysis of biomass feedstock

Abstract

To provide a method capable of obtaining a monocyclic aromatic compound such as benzene, toluene or xylene which is a basic chemical and a carbon material raw material such as pitch while using biomass as a raw material.SOLUTION: A hydropyrolysis method for hydropyrolyzing a biomass raw material containing lignin as biomass in the following steps (1) to (4): (1) Step of pulverizing the biomass feedstock to obtain pulverized biomass having a particle size of 1mm or less (2) Step of mixing a hydrogenated oil obtained by hydrogenating an aromatic hydrocarbon-containing oil in advance with the pulverized biomass to obtain a biomass slurry having a biomass feedstock concentration of 5% by mass or more and 45% by mass or less (3) Step of subjecting the biomass slurry obtained in step (2) to non-catalytic hydropyrolysis (4) Step of distilling the hydropyrolysis product obtained in step (3) to obtain a C6 to C8 aromatic hydrocarbon-containing light oil and a carbonaceous feedstock heavy oil SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for hydrothermal cracking of biomass feedstock, and more particularly to a method for hydrothermal cracking of biomass feedstock, which can obtain light oil containing basic chemicals and heavy oil containing carbonaceous material by hydrothermal cracking of biomass feedstock. [Background technology]

[0002] Due to growing awareness of carbon neutrality against the backdrop of global warming, which is thought to be the result of greenhouse gases such as carbon dioxide (CO2), various initiatives are being undertaken.

[0003] For example, in the steel industry, there is expected to be a shift from blast furnaces, which reduce and melt iron ore with coke to produce pig iron, to electric furnaces, which use scrap iron as raw material.However, the suspension of coke oven operations due to the shift to electric furnaces in the steel industry will mean a long-term decrease in the amount of coal tar, a coal dry distillation oil.

[0004] Coal tar distillates can be used to obtain basic chemicals such as benzene, toluene, and xylene, as well as binders for molded coal, pitch for impregnation, graphite electrodes, carbon black, and other carbon material raw materials. Therefore, coal tar is used in a wide range of applications, but if its supply decreases, it will be necessary to secure new raw materials for basic chemicals and the graphite electrode material itself for the shift to electric furnaces.

[0005] Among these, the use of biomass is attracting attention. Because biomass has the characteristic of being carbon neutral, meaning it does not affect the carbon dioxide concentration in the atmosphere, its use can reduce carbon dioxide emissions and contribute to preventing global warming.

[0006] For example, a method is known in which woody biomass-derived liquid fuel is obtained by mixing an organic solvent such as anthracene, naphthalene, or tetralin with woody biomass, subjecting the mixture to thermal decomposition and liquefaction at 250 to 400°C, and separating the decomposition products produced by heating (see Patent Document 1).

[0007] Among biomass, woody biomass is composed of substances such as cellulose, hemicellulose, and lignin. Cellulose in particular is not only widely used as a raw material for paper, but technology has also been established to ferment cellulose to obtain fuel oils such as bioethanol, making it a relatively active source of biomass development.

[0008] The method disclosed in Patent Document 1 is also aimed at producing liquid fuels such as gasoline, petroleum, kerosene, etc., and is not intended to produce basic chemicals that have traditionally been made from coal tar as a raw material, or carbon material raw materials such as pitch.

[0009] On the other hand, a method is known in which lignin, one of the main components of biomass, is heat-treated at 300 to 700°C in the presence of a zeolite catalyst to obtain aromatic compounds such as benzene and toluene from lignin (see Patent Document 2).Also known is a method in which a slurry containing lignin is contacted with hydrogen in the presence of a catalyst at 190 to 370°C to convert the lignin into lignin conversion products such as phenols, benzene, toluene, xylene, etc. (see Patent Document 3).

[0010] The lignin used in these methods is a high-molecular-weight phenolic compound containing many aromatic rings. Because of its high molecular weight, it is less reactive than cellulose. Therefore, high energy (high temperature) is generally required to decompose the lignin, and much of the lignin is reused as a heat source by combustion.

[0011] In contrast, the methods described in Patent Documents 2 and 3 are said to be capable of producing basic chemicals such as benzene and toluene, but require the use of a catalyst made of a platinum group element such as ruthenium, rhodium, palladium, iridium, or platinum (Patent Document 3) or a zeolite catalyst carrying such a catalyst (Patent Document 2), which poses a cost problem for industrial use. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Patent No. 4798477 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-127022 [Patent Document 3] Special Publication No. 2015-508093 Summary of the Invention [Problem to be solved by the invention]

[0013] As mentioned above, a shift from blast furnaces to electric furnaces in the steel industry is inevitable to some extent. At the same time, new methods must be established to produce basic chemicals and carbon materials that have traditionally been obtained from coal tar.

[0014] Therefore, the present inventors conducted extensive research to solve the above problems, and as a result, they discovered that by using biomass having carbon-neutral properties as a raw material, pulverizing the biomass, mixing it with a hydrogenation solvent obtained by hydrogenating aromatic hydrocarbon-containing oil, and forming a biomass slurry, and then hydrothermally cracking the slurry, it is possible to obtain light oil containing basic chemicals and heavy oil containing carbon material raw materials, even without a catalyst, and thus completed the present invention.

[0015] Therefore, an object of the present invention is to provide a method for obtaining monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene, which are basic chemicals, and carbonaceous raw materials such as pitches, using biomass, a carbon-neutral renewable resource, as a raw material, instead of using conventional coal tar. [Means for solving the problem]

[0016] That is, the gist of the present invention is as follows. [1] A method for hydropyrolysis of biomass feedstock, in which a biomass feedstock containing lignin as biomass is hydropyrolyzed by the following steps (1) to (4): (1) A step of crushing the biomass raw material to obtain biomass powder having a particle size of 1 mm or less. (2) A step of mixing the biomass powder with a hydrogenated solvent obtained by previously hydrogenating an aromatic hydrocarbon-containing oil to obtain a biomass slurry having a biomass raw material concentration of 5% by mass or more and 45% by mass or less. (3) Hydropyrolyzing the biomass slurry obtained in step (2) without a catalyst. (4) A step of distilling the hydrothermal cracking product obtained in the step (3) to obtain a light oil containing C6 to C8 aromatic hydrocarbons having a carbon number of 6 to 8 and a carbon material feedstock heavy oil. [2] The method for hydropyrolysis of a biomass feedstock according to [1], wherein in the step (3), the biomass slurry is hydropyrolyzed at a temperature of 250 to 500°C and a pressure of 0.3 to 8.0 MPa (gauge pressure). [3] The method for hydrothermal decomposition of biomass feedstock according to [1] or [2], wherein in step (3), hydrothermal decomposition is carried out under an inert gas atmosphere. [4] The method for hydropyrolysis of a biomass material according to any one of [1] to [3], wherein the biomass material contains 10 mass % or more of woody or herbaceous lignin in the biomass. [Effects of the Invention]

[0017] According to the present invention, basic chemicals such as benzene, toluene, xylene, etc. can be obtained from biomass, which is a carbon-neutral renewable resource, as a raw material, and carbon material raw materials such as binders for molded carbon, pitch for impregnation, graphite electrodes, and carbon black can also be obtained.

[0018] Therefore, it is possible to address the decrease in coal tar supply while taking into consideration environmental issues such as global warming. Moreover, since it does not require expensive platinum group elements as a catalyst, it can be said to be an industrially useful method. Furthermore, the establishment of the new method of the present invention will make it possible to secure coal tar, a valuable material, as a raw material for, for example, graphite electrodes required for electric furnaces. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is an explanatory diagram that schematically shows the procedures and steps of the method for hydropyrolysis of biomass feedstock according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] In this specification, aromatic hydrocarbons with 6 to 8 carbon atoms, such as benzene, toluene, and xylene, are referred to as "C6 to C8 aromatic hydrocarbons," and light oils containing these aromatic hydrocarbons are referred to as "C6 to C8 aromatic hydrocarbon-containing light oils." Note that "C6 to C8 aromatic hydrocarbons," which are aromatic hydrocarbons with 6 to 8 carbon atoms, are sometimes simply referred to as "basic chemicals," and light oils containing these are sometimes referred to as "basic chemical-containing light oils."

[0021] The present invention will be described in detail below.

[0022] The method for hydropyrolysis of biomass feedstock in the present invention is capable of obtaining light oil containing C6 to C8 aromatic hydrocarbons and heavy oil as a carbon material feedstock by hydropyrolyzing a biomass feedstock containing lignin as biomass in the following steps (1) to (4). (1) A step of crushing the biomass raw material to obtain biomass powder having a particle size of 1 mm or less. (2) A step of mixing the biomass powder with a hydrogenated solvent obtained by previously hydrogenating an aromatic hydrocarbon-containing oil to obtain a biomass slurry having a biomass raw material concentration of 5% by mass or more and 45% by mass or less. (3) Hydropyrolyzing the biomass slurry obtained in step (2) without a catalyst. (4) A step of distilling the hydrothermal cracking product obtained in the step (3) to obtain a light oil containing C6 to C9 aromatic hydrocarbons having a carbon number of 6 to 8 and a carbon material feedstock heavy oil.

[0023] In step (1), the biomass raw material is pulverized to a particle size of 1 mm or less, preferably 10 to 500 μm, to produce biomass powder. The pulverization method is not particularly limited. A ball mill or a blender (small pulverizer) typically used for pulverizing woody biomass may be used. If the biomass is sticky and difficult to pulverize, a freeze pulverizer may also be used. To prevent excessive heat from being applied to the biomass raw material during pulverization, a pulverizer equipped with a cooling mechanism, such as a Centri-Cutter (manufactured by Nippon Coke & Engineering Co., Ltd.), or an airflow pulverizer, such as a jet mill, may be used. Furthermore, since biomass raw materials vary in properties depending on the type, it is preferable to perform pretreatment, such as drying, removal of foreign matter such as metals and resins, neutralization, or separation, as necessary, before pulverization. The particle size of the biomass raw material refers to the size measured when sieved through a sieve with a specified mesh size, as described in the examples.

[0024] Here, biomass raw materials are raw materials whose substantial main components are, for example, woody biomass derived from trees such as cedar, herbaceous biomass derived from herbs such as kenaf, seaweed-derived biomass, and biomass derived from fungal products. These include waste materials such as discarded paper products, plant fiber products such as cotton and hemp, livestock manure, food waste, construction waste, sawmill residue, black liquor, sewage sludge, and so-called unused materials such as rice straw, wheat straw, rice husks, thinned wood, and damaged trees, as well as resource crops cultivated for the purpose of energy or product production, such as sugarcane, corn, cotton, hemp, and cotton. However, due consideration must be given to the ease of availability, the impact of procurement on the market and the environment, and the effort required for pretreatment and removal of impurities. Therefore, it is preferable to use waste materials or unused materials with relatively few impurities, such as black liquor and sawmill residue, as biomass raw materials.

[0025] Biomass contained in biomass feedstock includes cellulose, hemicellulose, lignin, starch, etc., and these components are present in various proportions depending on the characteristics of the biomass feedstock as described above. When using biomass feedstock, these components may be used as a mixture. However, to obtain both basic chemical-containing light oil and carbon material feedstock heavy oil, which is the gist of the present invention, the biomass feedstock must contain lignin. From the perspective of recovering relatively large amounts of these components, a biomass feedstock containing 10% by mass or more of lignin is preferred. A biomass feedstock containing 15% by mass or more of lignin is more preferred, a biomass feedstock containing 25% by mass or more of lignin is even more preferred, and a biomass feedstock containing 30% by mass or more of lignin is most preferred. Note that the lignin content is the ratio of the mass of lignin contained per 100 parts by mass of biomass in the biomass feedstock. The upper limit of the lignin content is difficult to specify because it varies depending on the type of biomass contained in the biomass raw material as described above, but for example, the lignin content in woody biomass is said to be at most about 35% by mass. However, as described below, if the lignin is purified, it is possible to increase the lignin content to 100% by mass.

[0026] Such suitable biomass raw materials include, for example, woody biomass and herbaceous biomass, and materials derived from these, among the biomass raw materials mentioned above. However, since the lignin content is higher in woody biomass than in herbaceous biomass, preferably those containing woody biomass and biomass derived from these, more preferably those containing woody biomass derived from coniferous trees and biomass derived from these, or lignin purified from these may be used as the biomass raw material.

[0027] Next, in step (2), a hydrogenated solvent, which is obtained by previously hydrogenating an aromatic hydrocarbon-containing oil, is mixed with the biomass powder prepared in step (1) to obtain a biomass slurry with a biomass feedstock concentration of 5% by mass or more and 45% by mass or less. Here, the hydrogenated solvent is a solvent with hydrogen donating ability, which is used to generate hydrogen radicals through a pyrolysis reaction in step (3) after mixing with the biomass powder to obtain a biomass slurry. An aromatic hydrocarbon-containing oil, which is an aromatic oil containing aromatic hydrocarbons, can be used as the feedstock for this hydrogenated solvent, and the hydrogenated solvent can be obtained by previously hydrogenating this. In order to obtain a biomass slurry, a dispersant may be used to improve workability when mixing the pulverized biomass raw material with the hydrogenation solvent and to obtain a slurry with good properties. The dispersant is not particularly limited as long as it does not have a particularly adverse effect on the subsequent steps.

[0028] The aromatic hydrocarbon-containing oil used as the feedstock for the hydrogenated solvent is preferably a hydrogenated aromatic oil having hydrogen donating ability due to aromatic compounds with two or more rings, and this is preferably used as the hydrogenated solvent. More preferably, hydrogenated anthracene oil obtained by hydrogenating anthracene oil obtained by distilling coal tar is used as the hydrogenated solvent. The distillate oil obtained by distilling coal tar contains fractions with a boiling point in the range of 200 to 380°C, mainly composed of aromatic compounds with two to five rings, such as naphthalene oil, wash oil, or anthracene oil. Of these, anthracene oil contains large amounts of polycyclic aromatic compounds such as anthracene, phenanthrene, and carbazole. When hydrogenating aromatic hydrocarbon-containing oils, hydrogenation techniques commonly used in the hydrogenation, reforming, or refining of petroleum or tar distillate oils can be used as is. The hydrogenation ratio of the hydrogenated solvent is preferably such that the aromatic carbon index fa measured by NMR is 0.3 to 0.7, preferably 0.4 to 0.6.

[0029] The biomass feedstock concentration in the biomass slurry is 5% by mass or more and 45% by mass or less, preferably 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 20% by mass or less. By setting the biomass feedstock concentration to 5% by mass or more, basic chemical-containing light oil and carbon material feedstock heavy oil can be reliably obtained. On the other hand, by setting the biomass feedstock concentration to 45% by mass or less, the reaction with hydrogen in step (3) described below can be promoted.

[0030] Next, in step (3), the biomass slurry obtained in step (2) is hydropyrolyzed without a catalyst. Here, for the biomass slurry obtained in step (2), for example, a hydrogenation solvent obtained by hydrogenating anthracene oil converts some of the aromatic rings in polycyclic aromatic compounds into naphthenic structures. These naphthenic compounds release hydrogen radicals in response to radicals generated by biomass decomposition. Biomass decomposition begins at approximately 200°C, and the hydrogenation solvent releases hydrogen radicals in response to radicals generated by the biomass decomposition, inhibiting polymerization. As a result, lignin is decomposed into a light oil containing C8-C9 aromatic hydrocarbons and a heavy oil feedstock for carbon materials. Because hydropyrolysis in step (3) proceeds under relatively mild reaction conditions, the reaction temperature (slurry temperature) is preferably 250-500°C, and more preferably 350-440°C.

[0031] During this hydropyrolysis, hydrogen radicals released from the hydrogenation solvent combine with radicals from the pyrolysis product of the biomass powder, resulting in the degradation of the biomass powder into smaller molecules. Therefore, there is no need to dissolve high-pressure hydrogen gas separately in the slurry for the pyrolysis reaction. Since the biomass feedstock is directly hydropyrolyzed between the hydrogenation solvent and the slurry, the reaction pressure can be 10 MPa or less (gauge pressure). Hydropyrolysis can be carried out preferably at 0.3 to 8.0 MPa (gauge pressure), and more preferably at 0.98 to 6.0 MPa (gauge pressure). At these reaction temperatures and pressures, hydropyrolysis can be carried out without a catalyst for a retention time of approximately 0 to 360 minutes, preferably 40 to 160 minutes.

[0032] Next, in step (4), the hydrothermal cracker obtained in step (3) is distilled, that is, the hydrothermal cracker obtained in step (3) is separated by this distillation into a light oil containing basic chemicals, a hydrogenation solvent, and a carbon material feedstock heavy oil.

[0033] The distillation in step (4) is preferably performed by vacuum distillation in order to prevent decomposition of residual oils such as light oil containing basic chemicals and carbon material feedstock heavy oil. The softening point of the resulting carbon material feedstock heavy oil can be adjusted by changing the distillation conditions (generally about 28 to 39°C). Furthermore, the distillation conditions vary depending on the type of hydrogenation solvent used in step (2), making it difficult to specify them in general terms. However, for example, when the hydrogenation solvent is hydrogenated anthracene oil, vacuum distillation can be performed at a temperature of about 250 to 350°C and a pressure of about 0.01 to 30 kPa.

[0034] FIG. 1 shows a schematic diagram of the procedure and steps of the hydropyrolysis method of the present invention, which includes steps (1) to (4). Among these, the C6-C8 aromatic hydrocarbon-containing light oil contains aromatic hydrocarbons with 6 to 8 carbon atoms, such as benzene, toluene, and xylene, which are also called basic chemicals, as well as phenols. The carbonaceous material feedstock heavy oil includes, for example, binders used in obtaining molded coal, and various carbonaceous material feedstocks used to produce impregnation pitch, graphite electrodes, carbon black, and the like. Therefore, according to the present invention, by mixing a biomass feedstock with a hydrogenation solvent and pyrolyzing the mixture, basic chemicals and carbonaceous material feedstocks can be obtained without going through coal tar. The hydrogenated solvent separated by distillation is preferably hydrogenated again and recycled as the hydrogenated solvent. [Example]

[0035] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, various measurements and evaluations were carried out as follows, unless otherwise specified.

[0036] (Physical property evaluation) ·Elemental analysis The analysis was conducted in accordance with JIS M 8819:1997 Coals and cokes - Elemental analysis method using an instrumental analyzer.

[0037] ·Industrial analysis JIS M 8812:2004 Coals and cokes - proximate analysis method was followed.

[0038] Basic chemicals ratio 0.1 g of distilled light oil containing basic chemicals was diluted with 2.0 g of acetone and diluted with 0.01 g of decane as an internal standard. The basic chemicals were identified by gas chromatography and quantified using the peak intensity of decane as the internal standard. The gas chromatograph was an Agilent 7890A gas chromatograph (Agilent Technologies) and the column was a TC-1 (GL Sciences).

[0039] Carbon material raw material ratio (solvent fraction) Three types of solvents, hexane, toluene, and quinoline, were prepared. 10 g of the sample to be measured was dissolved in 50 mL of solvent (hexane or toluene) heated to 60°C or 50 mL of solvent (quinoline) heated to 80°C. After stirring, the solution was centrifuged at 80°C, 3000 rpm, and 10 minutes, and the supernatant was removed. Next, 50 mL of reheated solvent (the same solvent used previously, but heated again to the specified temperature) was added to the precipitate, stirred, and centrifuged. Centrifugation was repeated up to five times until the color of the supernatant disappeared, and the ratio of the mass of the precipitate to the original mass of the measurement sample (10 g) was calculated and used as the insoluble content of each solvent.

[0040] Aromatic carbon index The 13C-NMR spectrum was measured using a nuclear magnetic resonance (NMR) spectrometer, and the ratio of the peak integrated area value showing aromatic carbon with a chemical shift of 170 to 100 ppm to the total peak integrated area value was calculated as the aromatic carbon index.

[0041] [Production method under condition 1] First, in step (1), 1 kg of woody biomass A was prepared as a raw material, which was then pulverized in a blender (small grinder) and passed through a sieve with 500 μm openings, and the under-sieve fraction was prepared as fine powder raw material A (biomass powder A). The results of elemental analysis of this fine powder raw material A are shown in Table 1, and the results of proximate analysis are shown in Table 2.

[0042] [Table 1]

[0043] [Table 2]

[0044] Next, in step (2), hydrogenated anthracene oil obtained by distilling coal tar was used as a hydrogenation solvent, which was mixed with the fine powder raw material A obtained in step (1) above and stirred at 60°C to form a slurry, thereby obtaining a biomass slurry with a biomass raw material concentration of 20% by mass. The hydrogenation ratio of the hydrogenated anthracene oil used as the hydrogenation solvent was 0.4 to 0.5.

[0045] Next, in step (3), the biomass slurry obtained above was placed in a reactor equipped with a reflux condenser, pressurized to 0.98 MPa (gauge pressure) by injecting nitrogen, and heated to 380°C at a rate of approximately 4°C / min while stirring (no reaction holding time), thereby carrying out hydropyrolysis without a catalyst.

[0046] Next, in step (4), the hydropyrolysis product obtained in step (3) was distilled. Specifically, the resulting hydropyrolysis product was subjected to reduced-pressure distillation at a temperature of 330°C and a pressure of 0.5 kPa to recover the light oil components and hydrogenation solvent, and a hydropyrolysis heavy product (heavy oil) was obtained as the residual oil. The proportions of basic chemicals in the resulting light oil components were calculated, as well as the proportion of carbonaceous raw material (resin amount) in the hydropyrolysis heavy product. Table 3 shows the proportions of basic chemicals, and Table 4 shows the proportions of carbonaceous raw material (resin amount). Tables 3 and 4 show the proportions of each component when the fine powder raw material A used as the raw material is taken as 100 mass% (expressed as wt%). Table 5 also lists the experimental conditions for the manufacturing method under condition 1 (hydropyrolysis method). The amount of γ-resin component in Table 4 represents the difference between the amount of hexane-insoluble matter and the amount of toluene-insoluble matter in the solvent fractionation results. Similarly, the amount of β-resin component indicates the difference between the amount of toluene insoluble matter and the amount of quinoline insoluble matter in the solvent fractionation results. Furthermore, QI indicates the amount of quinoline insoluble matter.

[0047] [Table 3]

[0048] [Table 4]

[0049] [Table 5]

[0050] [Production method under condition 2] Production (hydropyrolysis) under Condition 2 was carried out in the same manner as in the production method under Condition 1, except that in step (3), the temperature was raised to 380°C at a rate of approximately 4°C / min, and then the reaction was held for 40 minutes to carry out hydropyrolysis. The obtained proportions of basic chemicals and carbonaceous raw material (resin amount), as well as the production conditions, are shown in Tables 3 to 5, respectively.

[0051] [Production method under condition 3] Production (hydropyrolysis) under Condition 3 was carried out in the same manner as in the production method under Condition 1, except that in step (3) the temperature was raised to 400°C at a rate of approximately 4°C / min. The obtained proportions of basic chemicals and carbonaceous raw material (resin amount), as well as the production conditions, are shown in Tables 3 to 5, respectively.

[0052] [Production method under condition 4] Production (hydropyrolysis) under Condition 4 was carried out in the same manner as in the production method under Condition 1, except that in step (3), the temperature was raised to 440°C at a rate of approximately 4°C / min, and then the reaction was held for 160 minutes to carry out hydropyrolysis. The obtained proportions of basic chemicals and carbonaceous raw material (resin amount), as well as the production conditions, are shown in Tables 3 to 5, respectively.

[0053] [Production method under condition 5] In step (1), 1 kg of woody biomass B was prepared as a raw material, pulverized in a blender (small grinder), and passed through a 500 μm mesh sieve, with the undersieve material being designated as finely powdered raw material B (biomass powder B). Furthermore, in step (3), the temperature was increased to 380°C at a rate of approximately 4°C / min, and then the reaction was maintained for 40 minutes during hydrothermal decomposition. Production (hydrothermal decomposition) under condition 5 was carried out in the same manner as in the production method under condition 1. The obtained proportions of basic chemicals and carbonaceous raw material (resin amount), as well as the production conditions, are shown in Tables 3 to 5, respectively.

[0054] [Production method under condition 6] In step (1), 1 kg of woody biomass C was prepared as a raw material, pulverized in a blender (small grinder), and passed through a 500 μm mesh sieve, with the undersieve material being designated as fine raw material C (biomass powder C). Furthermore, in step (3), the temperature was raised to 380°C at a rate of approximately 4°C / min, and then the reaction was maintained for 40 minutes during hydrothermal decomposition. Production (hydrothermal decomposition) under condition 6 was carried out in the same manner as in the production method under condition 1. The obtained proportions of basic chemicals and carbonaceous raw material (resin amount), as well as the production conditions, are shown in Tables 3 to 5, respectively.

[0055] As can be seen from the above results, basic chemicals and carbonaceous raw materials were recovered from all of the various biomass feedstocks A to C. Furthermore, as can be seen from conditions 1 to 4, it is possible to change the production ratios of basic chemicals and carbonaceous raw materials by adjusting the biomass pyrolysis conditions.

[0056] Therefore, according to the present invention, basic chemicals and carbonaceous raw materials can be obtained by hydropyrolyzing biomass raw materials using a predetermined method. This allows coal tar, a valuable raw material, to be used as graphite electrode material, which makes it possible to address the decrease in coal tar supply while promoting carbon neutral initiatives.

Claims

1. A method for hydropyrolysis of biomass feedstock, in which a biomass feedstock containing lignin as biomass is hydropyrolyzed by the following steps (1) to (4). (1) A step of crushing the biomass raw material to obtain biomass powder having a particle size of 1 mm or less. (2) Mixing the biomass powder with a hydrogenated solvent obtained by previously hydrogenating an aromatic hydrocarbon-containing oil to obtain a biomass slurry having a biomass raw material concentration of 5% by mass or more and 45% by mass or less. (3) A step of hydro-pyrolyzing the biomass slurry obtained in the step (2) without a catalyst. (4) A step of distilling the hydrothermal cracking product obtained in the step (3) to obtain a light oil containing C6 to C8 aromatic hydrocarbons having a carbon number of 6 to 8 and a carbon material feedstock heavy oil.

2. The method for hydropyrolysis of biomass feedstock according to claim 1, wherein in the step (3), the biomass slurry is hydropyrolyzed at a temperature of 250 to 500°C and a pressure of 0.3 to 8.0 MPa (gauge pressure).

3. 3. The method for hydropyrolysis of biomass feedstock according to claim 1 or 2, wherein in step (3), hydropyrolysis is carried out under an inert gas atmosphere.

4. 3. The method for hydropyrolysis of biomass feedstock according to claim 1 or 2, wherein the biomass feedstock contains 10 mass % or more of woody or herbaceous lignin in the biomass.

Images