Carbon compound material, carbon-storing material containing carbon compound material, and method for producing carbon compound material

Abstract

To provide carbon compound material capable of effectively utilizing a saccharification residue, carbon storage material containing the carbon compound material, and a method for producing the carbon compound material.SOLUTION: Carbon compound material includes solid material made of biomass raw material containing at least one of cellulose or lignin, and the solid material has a carboxy group, where fixed carbon ratio is 20% or more, and an average diameter is 1 μ m or more and 1000 μ m or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a carbon compound material, a carbon storage material including a carbon compound material, and a method for producing a carbon compound material. [Background technology]

[0002] In recent years, technology for producing biomass fuels from non-food biomass (cellulosic biomass) such as wood, grass, and rice straw has been attracting attention as an alternative to food biomass such as sugar cane and corn.

[0003] Patent Document 1 describes a method for producing biomass fuel, in which a biomass raw material containing cellulose is pulverized under heating at a temperature of 100° C. or higher but lower than 300° C., and a saccharified liquid is extracted with water.

[0004] Patent Document 2 discloses a method for producing a saccharified liquid by contacting a carbonized material carbonized at a temperature of 150°C to 500°C with a biomass raw material containing cellulose and hydrolyzing the resulting mixture, and a method for using the saccharification residue obtained after extracting the saccharified liquid as a catalyst for the hydrolysis reaction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-111034 A [Patent Document 2] JP 2015-35973 A Summary of the Invention [Problem to be solved by the invention]

[0006] When producing biomass fuel from cellulosic biomass raw materials, it is necessary to decompose cellulose and extract the sugar portion. However, cellulose has a strong molecular structure and is not easy to decompose. A method of saccharifying cellulose using a strong acid such as sulfuric acid has been known for a long time, but when the strong acid is neutralized, a large amount of gypsum and other waste is generated, and the process is complicated and takes a long time, resulting in problems such as a large energy load during production. In addition, there are few examples of effective practical use of the non-sugar portion as saccharification residue, and there is an issue that most of it is discarded.

[0007] Patent Document 1 does not describe the saccharification residue after extraction of the saccharified solution, and does not disclose a method for utilizing the saccharification residue. In addition, Patent Document 2 discloses that the recovery efficiency of monosaccharides can be increased by using the saccharification residue as a catalyst for a hydrolysis reaction, but the polysaccharides, lignin, and the like contained in the saccharification residue cannot be decomposed by carbonized materials, and therefore the saccharification residue has not been utilized effectively.

[0008] Therefore, an object of the present invention is to provide a carbon compound material that can effectively utilize saccharification residues and biomass raw materials containing cellulose or lignin, carbon containing the carbon compound material, and a method for producing the carbon compound material. [Means for solving the problem]

[0009] The carbon compound material according to the present invention is characterized in that it comprises a solid material made of a biomass raw material containing at least one of cellulose and lignin, the solid material having a carboxy group, a fixed carbon rate of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

[0010] As described above, biomass raw materials containing at least one of cellulose and lignin are not easily decomposed, and the saccharification residues after sugar extraction are not effectively utilized. These biomass raw materials and saccharification residues are often used as solid fuels, and when they are burned, the carbon dioxide absorbed by the plants is released into the atmosphere. However, the carbon compound material in this configuration has a fixed carbon rate of 20% or more, so that it can stably store carbon for a long period of time. Therefore, the carbon dioxide absorbed by the plants can be kept in the carbon compound material without being released into the atmosphere, and it is possible to achieve a state in which the amount of carbon dioxide absorbed is greater than the amount of carbon dioxide emitted (carbon negative). In addition, since the average diameter is 1 μm or more and 1000 μm or less, it is possible to bury the solid material in the soil as fine powder, or to mix the solid material with a substance. Furthermore, since the solid material has a carboxyl group, it is possible to provide a material with high environmental compatibility. This makes it possible to effectively utilize the saccharification residues generated when producing biomass fuel and biomass raw materials other than wood to achieve carbon negative. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a process block diagram according to the first embodiment. [Diagram 2] FIG. 11 is a process block diagram according to a second embodiment. [Diagram 3] 1 shows the results of thermogravimetry according to Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the carbon compound material according to the present invention will be described with reference to the drawings. In this embodiment, as an example of the carbon compound material, a carbon compound material made from biomass containing at least one of cellulose and lignin will be described. However, the present invention is not limited to the following embodiment, and various modifications are possible within the scope of the present invention.

[0013] The solid material in the present invention is a biomass raw material containing at least one of cellulose and lignin. The biomass raw material containing at least one of cellulose and lignin is a raw material containing at least a component of cellulose or lignin. For example, grass or plant biomass such as rice straw, wheat straw, bagasse, etc., thinning materials such as bamboo and bamboo grass, wood processing waste such as sawdust, chips, and scraps, roadside tree pruning materials, wooden building waste, bark, driftwood, and wood-based biomass such as waste paper, and cellulose products such as waste paper can be used. In addition, sludge, livestock manure, agricultural waste, urban waste, etc. can also be used as long as they contain cellulose or lignin to an extent that they can be used as biomass raw materials. These biomass raw materials may be used alone or in combination of multiple different types, and may contain polysaccharides such as starch, hemicellulose, and pectin in addition to cellulose or lignin.

[0014] The solid material in the present invention has a fixed carbon ratio of 20% or more, preferably 30% or more, and more preferably 40% or more. The upper limit of the fixed carbon ratio is 100%, and a higher value indicates a higher content of flame-retardant carbon. In other words, the fixed carbon ratio is an index of whether carbon dioxide absorbed by plants can be stably fixed in a solid state as a carbon compound material for a long period of time without being released into the atmosphere, so the higher the fixed carbon ratio, the better.

[0015] The fixed carbon ratio can be measured by thermogravimetric analysis using a Q-500 device (manufactured by TA instruments). In other words, a 10 mg solid sample is heated from room temperature to 107°C at a rate of 30°C / min under a nitrogen atmosphere, and then held for 3 minutes (the loss in sample mass at the time the weight stabilizes is taken as "moisture"). Then, the sample is heated to 600°C at a rate of 50°C / min, and then heated to 900°C at a rate of 100°C / min, and held for 3 minutes (the loss in sample mass is calculated, and the moisture quantified at the same time is subtracted to give the value "volatile content"). The sample is then cooled to 815°C at a rate of 30°C / min, and the sample is switched from the nitrogen atmosphere to an oxygen atmosphere and held for 30 minutes. The loss in sample mass is calculated, and the moisture quantified at the same time is subtracted to give the value of the fixed carbon ratio.

[0016] The solid material in the present invention has a functional group of a carboxy group. It is presumed that such a functional group causes a chemical reaction due to a mechanochemical effect, which increases the fixed carbon rate and generates a carboxy group. When the solid material has a carboxy group, for example, the carboxy group is ionized in soil and bonds with fertilizer components such as Mg ions, resulting in good affinity with the soil. In addition, when the solid material is fixed to a substance, the carboxy group acts to increase the affinity, resulting in a material with excellent dispersibility. Therefore, it is possible to spread the carbon storage material made of the solid material on the soil or fix it to a substance.

[0017] The presence of a carboxyl group in the solid material of the present invention can be confirmed, for example, by measuring an infrared absorption spectrum using a Fourier transform infrared spectrometer. Specifically, the solid material is added to KBr to adjust it, and mixed uniformly using a mortar. The resulting mixture is then processed into pellets, and an infrared absorption spectrum is obtained using a Fourier transform infrared spectrometer FT / IR-6100 (manufactured by JASCO Corporation) to obtain a carboxyl group in the range of 3300 to 2500 cm. ―1 The absorption peak is judged to be due to the carboxyl functional group, and its presence or absence is evaluated. It can also be confirmed by solid-state 13C-NMR measurement.

[0018] The solid material in the present invention has an average diameter of 1 μm to 1000 μm, preferably 5 μm to 500 μm, more preferably 10 μm to 300 μm. Such an average diameter allows the solid material to be buried in the soil as a fine powder. In addition, when the solid material is mixed into a substance, the function and quality are improved, making it possible to fix the solid material in the substance for a long period of time.

[0019] In addition, the average diameter measurement in the present invention can be confirmed by measuring, for example, with a particle size distribution meter using the laser diffraction scattering method. Specifically, using LMS-2000e (manufactured by Seishin Enterprise Co., Ltd.), the volume average particle diameter of the solid material is measured by the wet method (ethanol solvent), and from the cumulative curve of the particle size distribution of the volume average particle diameter, the diameter of the particle corresponding to the central cumulative value is taken as the average diameter.

[0020] The solid material in the present invention is preferably insoluble in water. The term "insoluble" as used herein means a component that is not extracted as an aqueous solution when the solid material is washed with water. If the solid material is insoluble in water, the decomposition of the solid material is less likely to proceed, and it tends to be retained for a long time even when fixed in the ground or substances.

[0021] The solid material in the present invention preferably exhibits a peak at 650 °C or higher and 840 °C or lower in differential thermal analysis. Such a peak is derived from the recombination with hydrocarbon species fragmentation such as flame-retardant carbon content, and it becomes easier to maintain the solid material in a more stable state. Note that such analysis can be measured by differential thermal analysis using a differential thermal - thermogravimetric analyzer Q-600 device (manufactured by TA instruments). Specifically, a 10 mg solid sample can be measured from room temperature to 1000 °C at a heating rate of 30 °C / min in a nitrogen atmosphere, and confirmed by an exothermic peak detected at 650 °C or higher and 840 °C or lower.

[0022] 〔First Embodiment〕 Subsequently, the manufacturing method of the solid material according to the first embodiment will be described with reference to FIG. 1. The biomass raw material containing at least one of cellulose or lignin becomes a solid material through a coarse pulverization step 1 and a heat pulverization step 2.

[0023] The biomass raw material used in this embodiment is coarsely pulverized in the coarse pulverization step 1. It is preferable that the biomass raw material is pulverized to about 1 mm to 10 mm in the coarse pulverization step 1. In the coarse pulverization step 1, a pulverization method according to the form of the biomass raw material can be selected, and for example, a general-purpose pulverizer such as a hammer mill, a cutter mill, a vibration mill, a ball mill, a rod mill, a roller mill, a colloid mill, a disk mill, or a jet mill can be used. In addition, the pulverization treatment in the coarse pulverization step 1 can be either a dry or wet method, but dry pulverization is preferable in terms of reducing the crystallinity of cellulose and lignin. When the water content of the raw material is high, the crystallinity of cellulose and lignin can be efficiently reduced by reducing the water content to 30 mass% or less in advance by centrifugal dehydration or hot air drying, etc., before performing dry pulverization.

[0024] The coarsely pulverized biomass raw material used in this embodiment is subjected to a heating and pulverization process in the heating and pulverization step 2. The biomass raw material is heated and carbonized to increase the proportion of fixed carbon and become a carbon compound material. As described above, fixed carbon refers to carbon in a stable state calculated as the amount of combustible material remaining at high temperature and in an oxygen-free state. Such carbon compound material is usually produced by so-called "steaming" the biomass raw material. However, most of the carbon contained in the biomass raw material is discharged into the atmosphere as carbon dioxide when it is combined with oxygen by heating. In addition, in the past, the production of high-quality carbon compound material with a high fixed carbon rate required heating the biomass raw material at high temperature and for a long time, and when the carbon compound material was produced by this, there were cases where a large amount of carbon dioxide was generated and the yield was low. On the other hand, when the biomass raw material was heated at a low temperature and for a long time in order to reduce the amount of carbon dioxide generated, there was a problem that only a low-quality carbon compound material was obtained, although it was a high yield. In other words, there was a trade-off relationship between the amount of carbon dioxide generated and the quality of the carbon compound material, i.e., the fixed carbon rate.

[0025] Therefore, in the heating and grinding step 2, a heating and grinding process is performed using a ball mill under heating at 100°C or more and less than 300°C. The biomass raw material is heated and ground until the average diameter is 1 μm or more and 1000 μm or less, so that the solid material can be buried in soil in its original shape or fixed to a substance. The rotation speed is preferably in the range of more than 300 rpm and 2000 rpm. The higher the rotation speed, the easier it is for carbonization to proceed, but in consideration of the manufacturing energy and the load on the device, a rotation speed of more than 500 rpm and less than 2000 rpm is preferable, and more preferably, a rotation speed of more than 1000 rpm and less than 2000 rpm can be used to most efficiently obtain solid material. The atmosphere in the heating and grinding step 2 may be normal pressure or vacuum, or may be any atmosphere selected from the group consisting of oxygen, nitrogen, argon, and rare gas.

[0026] By carrying out a heating and grinding process using a ball mill under heating at 100°C or higher but lower than 300°C, the mechanochemical effect of heating and grinding can be obtained, and the decomposition of the biomass raw material can be promoted. In other words, it is presumed that the biomass raw material is decomposed into each component such as cellulose, hemicellulose, lignin, etc. by hydrolysis, the frictional heat and reaction heat from the ball mill activate the molecular motion of cellulose, etc., the decrease in crystallinity and the degradation of molecules are accelerated, and further, another reaction occurs, the molecules are repolymerized, and cyclization reactions and the like progress, resulting in a solid material with a high fixed carbon ratio.

[0027] The heating and grinding process is preferably carried out for 0.5 hours or more. Since the longer the time, the more the reaction such as repolymerization progresses, it is desirable to carry out the process for a long time, but in order to efficiently obtain a solid material, it is preferable to carry out the process for about 0.5 to 5 hours. As described above, by obtaining the mechanochemical effect, the biomass raw material can be carbonized at a low temperature and in a short time, so that a high-quality solid material can be obtained by a simple method compared to the conventional method. In addition, since no solvent or catalyst is used in the heating and grinding step 2, it is safe in terms of the carbonization process and it is possible to reduce the manufacturing cost.

[0028] The heating method is not particularly limited, and the container can be heated using an electric heater, high frequency, microwave, steam, or the like. The pulverization can also be performed using a ball mill such as a planetary ball mill. When a ball mill is used, the biomass raw material is subjected to a large gravitational acceleration from the balls, so that the mechanochemical effect due to pulverization can be greatly increased, and the biomass raw material can be carbonized in a short time. The heating and pulverization process can be performed at normal pressure or in a vacuum.

[0029] Second Embodiment 2 is a process block diagram of a method for producing a solid material according to a second embodiment. A biomass raw material containing at least one of cellulose and lignin is crushed through a coarse crushing step 1 and a heat crushing step 2, and then a water-soluble component is extracted in an extraction step 3. The other configurations are the same as those in the first embodiment, and therefore detailed explanations of the same configurations as those in the first embodiment will be omitted.

[0030] The pulverized material that has been subjected to the heating and pulverizing process in the heating and pulverizing step 2 contains monosaccharides or polysaccharides that are the raw material for biomass fuel. These are water-soluble components and can be extracted with water. Conventionally, the solubilization of biomass raw materials containing cellulose has been carried out by causing a hydrolysis reaction in the subcritical or supercritical region of water, but according to this embodiment, the processing can be carried out at a low temperature and in a short time by going through the heating and pulverizing step 2 and the extraction step 3. In addition, since the biomass raw materials can be solubilized and carbonized in a simple manner without using a solvent or a catalyst, the manufacturing energy is small and the process is safe. Furthermore, since the saccharification residue can be obtained as a solid material that can be used as a carbon storage material, etc., there is no need to carry out a process of processing the saccharification residue after solubilizing the biomass raw materials.

[0031] In this embodiment, the heating and grinding treatment is preferably carried out for about 0.5 to 5 hours.

[0032] In the extraction step 3, it is preferable to add water to the pulverized material obtained in the heating and pulverizing step 2 in an amount of 0.1 to 500 times, mix the pulverized material, and perform solid-liquid separation in a solid-liquid separator to obtain a solubilized solution and a solid material that is a saccharification residue. Examples of the solid-liquid separator include devices that use a gravity settling method, a centrifugal separation method, a membrane separation method, a flocculation separation method, a flotation separation method, etc.

[0033] The solubilized solution obtained in the extraction step 3 may be mixed and stirred with a solid acid catalyst to carry out hydrolysis, to produce a saccharified solution containing monosaccharides such as glucose as a main component. The saccharified solution thus obtained can be fermented or distilled to produce ethanol, a biomass fuel.

[0034] In the extraction process 3, the water-insoluble saccharification residue can be obtained as a solid material. The solid material can be used directly as a carbon compound material to make a carbon storage material, or can be molded and processed using the carbon compound material to make a carbon storage material. The solid material obtained in this way is a by-product of biomass fuel production, which leads to a reduction in carbon dioxide emissions in life cycle assessment.

[0035] [Example] Examples of the present invention will be described below, but the present invention is not limited to the description of these examples. First, the methods for evaluating various properties used in the examples will be specifically described.

[0036] (1) Fixed carbon rate evaluation Using a thermogravimetric analysis Q-500 device (manufactured by TA instruments), 10 mg of solid material was heated from room temperature to 107°C at a rate of 30°C / min under nitrogen atmosphere, and held for 3 minutes (the loss in mass relative to the sample mass at the time of weight stabilization was taken as "moisture"). Then, the temperature was raised to 600°C at a rate of 50°C / min, and then to 900°C at a rate of 100°C / min, and held for 3 minutes (the loss in mass relative to the sample mass was calculated, and the value obtained by subtracting the moisture quantified at the same time was taken as "volatile content"). The temperature was then lowered to 815°C at a rate of 30°C / min, and the sample was held for 30 minutes under an oxygen atmosphere after which the loss in mass relative to the sample mass was calculated, and the value obtained by subtracting the moisture and volatile content quantified at the same time was calculated as the fixed carbon ratio. The values ​​were calculated to one decimal place and rounded off to the nearest decimal place.

[0037] (2) Solubility evaluation When the solid material was washed with water in an amount 10 times the mass of the solid material, it was visually confirmed whether any of the solid matter remained as a solid matter without being extracted into an aqueous solution.

[0038] (3) Differential thermal analysis measurement A differential thermal analysis curve was obtained for 10 mg of solid material by heating from room temperature to 1000°C at a heating rate of 30°C / min under a nitrogen atmosphere using a differential thermal / thermogravimetric analyzer Q-600 (manufactured by TA instruments). Note that the characteristic exothermic peak associated with the development of condensed aromatic ring structures was assigned to the range of 650°C to 840°C based on the database of differential thermal analysis curves for forest harvested materials described in "Hirohisa Yoshida / Nobuyoshi Koga, Thermal Analysis 4th Edition, p.243-245, Kodansha Scientific."

[0039] (4) Carboxy functional group evaluation The solid material was added to KBr and mixed uniformly using a mortar. The resulting mixture was processed into pellets, and an infrared absorption spectrum was obtained using a Fourier transform infrared spectrometer FT / IR-6100 (manufactured by JASCO Corporation). ―1 The absorption peak was determined to be due to a carboxyl functional group, and the presence or absence of the carboxyl functional group was evaluated.

[0040] (5) Mean diameter measurement The volume average particle size of solid materials was measured by the wet method (ethanol solvent) using a laser diffraction scattering particle size distribution analyzer, LMS-2000e (manufactured by Seishin Enterprises). The particle size of the particle at the median cumulative value of the cumulative curve of the particle size distribution of the volume average particle size was taken as the average size.

[0041] Example 1 The cellulose reagent "Avicel" (registered trademark) PH-101 (Merck) was heated and crushed at 200°C for 1.5 hours at 800 rpm to 1600 rpm using a heater-equipped ball mill (ball 5 mm diameter). After heating and crushing, the obtained solid material was allowed to cool naturally and then various evaluations were carried out.

[0042] As shown in FIG. 3, the solid material obtained had a fixed carbon ratio of 50%, and a heat generation peak was detected between 650°C and 840°C in differential thermal analysis. ―1 Absorption peaks were detected, with an average diameter of 20 μm.

[0043] Example 2 A solid material was produced in the same manner as in Example 1, except that the heating and grinding conditions were changed to 170°C for 3 hours.

[0044] The solid material obtained had a fixed carbon content of 29%, and a heat generation peak was detected between 650 and 840 °C in differential thermal analysis. ―1 An absorption peak was detected, with an average diameter of 24 μm.

[0045] Comparative Example 1 A solid material was produced in the same manner as in Example 1, except that the conditions for the heat-grinding treatment were 200°C, 6 hours, and 300 rpm.

[0046] The solid material obtained had a fixed carbon content of 6%. ―1Although an absorption peak was detected, no exothermic peak was observed between 650°C and 840°C in the differential thermal analysis. The average diameter was 35 μm.

[0047] Comparative Example 2 A cellulose reagent, "Avicel" (registered trademark) PH-101 (Merck) was heat-treated for 1.5 hours in an electric furnace heated to 200° C. After heating, the obtained solid material was allowed to cool naturally in the same manner as in Example 1, and various evaluations were then carried out.

[0048] The solid material obtained had a fixed carbon rate of 3%. In addition, no exothermic peak was observed between 650° C. and 840° C. in differential thermal analysis. The average diameter was 43 μm.

[0049] Both the solid materials of Examples 1 and 2 achieved a fixed carbon ratio of 20% or more. On the other hand, the preparation conditions of Comparative Example 1 corresponded to Example 1 described in JP 2013-111034 A, and although the heating and crushing time was longer than that of Example 1, the fixed carbon ratio did not reach 20%. Moreover, in Comparative Example 2, which was heated in an electric furnace, the fixed carbon ratio was significantly reduced to 3%, even though the heating time was the same as that of Example 1.

[0050] In the above-described embodiment, the following configurations are envisaged. (1) A carbon compound material comprising a solid material made of a biomass raw material containing at least one of cellulose and lignin, the solid material having a carboxy group, a fixed carbon rate of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

[0051] As described above, biomass raw materials containing at least one of cellulose and lignin are not easily decomposed, and the saccharification residue after sugar extraction is not effectively utilized. These biomass raw materials and saccharification residues are often used as solid fuels, and when they are burned, the carbon dioxide absorbed by the plants is released into the atmosphere. However, the carbon compound material in this configuration has a fixed carbon rate of 20% or more, so that it can stably store carbon for a long period of time. Therefore, the carbon dioxide absorbed by the plants can be kept in the carbon compound material without being released into the atmosphere, and it is possible to achieve a state in which the amount of carbon dioxide absorbed is greater than the amount of carbon dioxide emitted (carbon negative). In addition, since the average diameter is 1 μm or more and 1000 μm or less, it is possible to bury the solid material in the soil as fine powder, or to mix the solid material with a substance. Furthermore, since it has a carboxyl group, it is possible to provide a material with high environmental compatibility and low environmental load. This makes it possible to effectively utilize cellulosic biomass and its saccharification residue to achieve carbon negative.

[0052] (2) In the carbon compound material of (1), it is preferable that the solid material is insoluble in water.

[0053] The water-soluble components of biomass raw materials (the sugar parts) are used as biomass fuel, but the water-insoluble components are often discarded as saccharification residue. With this configuration, the saccharification residue can be effectively used as a carbon storage material, making it possible to reduce the amount of by-products discarded during biomass fuel production.

[0054] (3) In the carbon compound material of (1) or (2), the solid material preferably exhibits a peak in a range of 650° C. or more and 840° C. or less in differential thermal analysis.

[0055] The peaks between 650 and 840°C in differential thermal analysis are presumed to be the result of the decomposition of cellulose and lignin, the main components of biomass raw materials, and the repolymerization of low molecular weight hydrocarbon species. Because such components have a high carbon content, carbon compound materials that show exothermic peaks in differential thermal analysis in this temperature range are useful as carbon storage materials.

[0056] (4) A carbon storage material comprising any one of the carbon compound materials (1) to (3).

[0057] According to this configuration, it is possible to provide a carbon storage material that can stably store carbon for a long period of time and has high environmental friendliness.

[0058] (5) A method for producing a carbon compound material, comprising: a coarse grinding step 1 for coarsely grinding a biomass raw material containing at least one of cellulose and lignin; and a heating and grinding step 2 for heating and grinding the coarsely ground biomass raw material, wherein the heating and grinding step 2 is carried out using a ball mill under heating at 100°C or higher but lower than 300°C.

[0059] When biomass raw materials are pyrolyzed, the ratio of fixed carbon increases and they become carbon compounds. Such carbon compounds are produced by so-called "steaming" of biomass raw materials. However, when the carbon contained in biomass raw materials is heated and combined with oxygen, it is emitted into the atmosphere as carbon dioxide. Conventionally, high-quality carbon compounds require heating of biomass raw materials at high temperatures for a long time, and producing carbon compounds in this way can result in a large amount of carbon dioxide being generated and a low yield. In addition, when biomass raw materials are heated at low temperatures for a long time to reduce the amount of carbon dioxide generated, there is a problem that only low-quality carbon compounds are obtained, although the yield is high. In other words, there is a trade-off between the amount of carbon dioxide generated and the quality of the carbon compounds, i.e., the fixed carbon rate.

[0060] However, by carrying out the carbon compound material manufacturing method including the coarse crushing step 1 and the heat crushing step 2 as in the present configuration, it is possible to reduce the amount of carbon dioxide generated and obtain a high-quality carbon compound material with a high yield. In the coarse crushing step 1, the biomass raw material can be made into a shape that is easy to handle. In the heat crushing step 2, the molecular motion of cellulose or lignin is activated by heating, and the cellulose or lignin can be decrystallized by crushing and the molecular weight can be reduced, so that the biomass raw material can be carbonized at a low temperature and in a short time by the mechanochemical effect. In particular, in this configuration, the heat crushing step 2 is performed using a ball mill under a low-oxygen atmosphere and a relatively low heating temperature of 100°C or higher and lower than 300°C, so that it is possible to suppress the generation of carbon dioxide associated with oxidation, and a high-quality carbon compound material can be obtained with a high yield. In addition, since no solvent or catalyst is used, the manufacturing process is simple, the energy load during manufacturing is small, and the generated carbon compound material has high environmental compatibility. Furthermore, since the present configuration can also obtain carbon compound materials from biomass raw materials other than wood, it is useful as a negative emission technology.

[0061] In the manufacturing process of the carbon compound material of (6)(5), it is preferable that the heating and crushing step 2 rotates at a speed of more than 300 rpm and less than 2000 rpm.

[0062] According to this configuration, the higher the rotation speed in the heating and crushing step 2, the more easily the carbonization proceeds, so that a solid material can be obtained efficiently.

[0063] (7) In the process for producing the carbon compound material of (5) or (6), it is preferable to further include an extraction step 3 of extracting water-soluble components of the solid material obtained in the heating and crushing step 2 with water.

[0064] The inclusion of extraction step 3, in which the water-soluble components of the carbon compound material are extracted with water, makes it possible to use the water-soluble components as biomass fuel. Furthermore, by using the residue after extraction as the carbon compound material, it is possible to reduce carbon dioxide emissions in the life cycle assessment, making it possible to effectively utilize the biomass raw material.

[0065] Other embodiments (1) In the above embodiment, the heat-pulverization was performed at 100° C. to 300° C. for 0.5 to 5 hours. However, the solubilization rate of the biomass raw material may be measured in advance, and the heat-pulverization treatment may be performed at the reaction time and reaction temperature at which the solubilization rate is maximized.

[0066] (2) The solid material obtained by carrying out the present invention may be mixed with fertilizer components and granulated to produce a carbon compound material. In this way, the carbon compound material not only functions as a carbon storage material, but can also be effectively used as a soil improvement material or fertilizer. [Industrial Applicability]

[0067] INDUSTRIAL APPLICABILITY The present invention is applicable to a carbon compound material capable of effectively utilizing saccharification residue, a carbon storage material containing a carbon compound material, and a method for producing a carbon compound material. [Explanation of symbols]

[0068] 1: Coarse grinding process, 2: Heat grinding process, 3: Extraction process

Claims

1. A solid material made of a biomass raw material containing at least one of cellulose and lignin, The solid material is a carbon compound material having a carboxy group, a fixed carbon ratio of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

2. The carbon compound material of claim 1 , wherein the solid material is insoluble in water.

3. The carbon compound material according to claim 1 , wherein the solid material exhibits a peak at 650° C. or more and 840° C. or less in differential thermal analysis.

4. A carbon storage material comprising the carbon compound material according to any one of claims 1 to 3.

5. A coarse crushing step of coarsely crushing a biomass raw material containing at least one of cellulose and lignin; A heating and grinding step of heating and grinding the coarsely ground biomass raw material, The method for producing a carbon compound material, wherein the heating and crushing step is carried out using a ball mill under heating at 100° C. or higher and lower than 300° C.

6. The method for producing a carbon compound material according to claim 5 , wherein the heating and crushing step rotates the material at a speed of more than 300 rpm and less than 2000 rpm.

7. 7. The method for producing a carbon compound material according to claim 5, further comprising an extraction step of extracting, with water, a water-soluble component of the solid material obtained by the heating and crushing step.

Images