Carbon compound material, carbon storage material comprising carbon compound material, and method for producing carbon compound material

Abstract

The present invention addresses the problem of providing a carbon compound material capable of effectively utilizing saccharification residues, a carbon storage material containing the carbon compound material, and a method for producing the carbon compound material. [Solution] A carbon compound material provided with a solid material comprising a biomass starting material containing cellulose and / or lignin, the solid material having a carboxyl group, a fixed carbon rate of 20% or more, and an average diameter of 1 [mu] m to 1000 [mu] m (inclusive).

Description

Technical Field

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

[0002] In recent years, technology for producing biomass fuel from non-food biomass (cellulose-based biomass) such as wood, grass, and straw has attracted attention instead of food-based biomass such as sugar cane and corn.

[0003] Patent Document 1 describes a method for producing a biomass fuel, in which a biomass raw material containing cellulose is pulverized under heating at 100° C. or higher and 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 bringing a carbonized product carbonized at 150° C. to 500° C. into contact with a biomass raw material containing cellulose to hydrolyze the product, and a method for using a saccharified residue after extracting the saccharified liquid as a catalyst for the hydrolysis reaction.

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2013-111034

[0006] [Patent Document 2] Japanese Patent Application Publication No. 2015-35973

[0007] When manufacturing biomass fuel from cellulose-based biomass raw materials, it is necessary to decompose cellulose and take out the part that becomes sugar. However, since cellulose has a strong molecular structure, it is not easy to decompose it. It has always been known that a method of saccharifying cellulose using strong acids such as sulfuric acid is used, but in the case of neutralization treatment with strong acids, the process of producing gypsum and the like as waste is complicated and takes a long time. For these reasons, there are problems such as large energy load during manufacturing. In addition, there are few examples of parts other than sugar being effectively put into practical use as saccharification residues, and there are a lot of issues that are discarded.

[0008] Patent Document 1 does not describe saccharification residues after extraction of saccharification liquid, and does not disclose a method for utilizing the saccharification residues. In addition, Patent Document 2 discloses that the recovery efficiency of monosaccharides can be increased by using the saccharification residues as a catalyst for hydrolysis reaction, but polysaccharides and lignin contained in the saccharification residues cannot be decomposed by carbonization, so the saccharification residues are not effectively utilized. Summary of the invention

[0009] Therefore, an object of the present invention is to provide a carbon compound material capable of effectively utilizing saccharification residues, a biomass raw material containing cellulose or lignin, carbon containing the carbon compound material, and a method for producing the carbon compound material.

[0010] The carbon compound material of the present invention is characterized in that it comprises a solid material composed of a biomass raw material containing at least one of cellulose or lignin, the solid material having a carboxyl group, a fixed carbon rate of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

[0011] Biomass raw materials containing at least one of cellulose or lignin are not easy to decompose as mentioned above, and the saccharification residue after extracting sugar is not effectively utilized. These biomass raw materials and saccharification residues are mostly used as solid fuels. If they are burned, the carbon dioxide absorbed by the plants is released into the atmosphere. However, the fixed carbon rate of the carbon compound material of this composition is more than 20%, thereby enabling long-term and stable storage of carbon. Therefore, the carbon dioxide absorbed by the plants can be retained in the carbon compound material without being released into the atmosphere, and a state in which the amount of carbon dioxide absorbed is greater than the amount of carbon dioxide emitted (carbon negative state) can be achieved. In addition, since the average diameter is more than 1 μm and less than 1000 μm, the solid material can be buried in the soil as a fine powder or the solid material can be mixed with the material. Furthermore, since the solid material has a carboxyl group, it is possible to provide a material with high environmental affinity. Thus, the saccharification residues and biomass raw materials other than wood produced when manufacturing biomass fuels can also be effectively utilized to achieve carbon negativity. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a process flow chart of the first embodiment.

[0013] Figure 2 This is a process flow chart of the second embodiment.

[0014] Figure 3 This is the result of the thermogravimetric measurement of Example 1.

[0015] [Explanation of Reference Numerals]

[0016] 1: Coarse pulverization process, 2: Heating pulverization process, 3: Extraction process DETAILED DESCRIPTION

[0017] Hereinafter, an embodiment of the carbon compound material of the present invention will be described based on the accompanying drawings. In this embodiment, as an example of the carbon compound material, a carbon compound material using biomass containing at least one of cellulose or lignin as a raw material will be described. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

[0018] The solid material in the present invention is composed of a biomass raw material containing at least one of cellulose or lignin. The biomass raw material containing at least one of the cellulose or lignin is a raw material containing at least the components of cellulose or lignin. For example, grasses or plant biomass such as straw, wheat straw, bagasse, bamboo, bamboo leaves and other thinning materials, sawdust, chips, scraps and other wood processing wood chips, street tree pruning materials, wooden construction waste materials, bark, driftwood and other wood-based biomass, cellulosic products such as waste paper, etc. can be cited. In addition, as long as it contains the degree that cellulose or lignin can be used as a biomass raw material, sludge, animal manure, agricultural waste, urban garbage, etc. can also be used. These biomass raw materials can be used alone, and a variety of different types can also be combined. For example, in addition to cellulose or lignin, polysaccharides such as starch, hemicellulose, and pectin can also be contained.

[0019] The fixed carbon rate of the solid material in the present invention is 20% or more, preferably 30% or more, and more preferably 40% or more. The upper limit of the fixed carbon rate is 100%. If the value is high, it means that it contains a large amount of flame-retardant carbon components. That is, the fixed carbon rate is an indicator of whether the carbon dioxide absorbed by the plant is not released into the atmosphere and can be stably fixed in a solid state for a long time as a carbon compound material, so the higher the fixed carbon rate, the better.

[0020] The fixed carbon rate mentioned here can be measured by thermogravimetric analysis using a Q-500 device (manufactured by TAinstruments). That is, 10 mg of a solid sample is heated from room temperature to 107°C at a rate of 30°C / min in a nitrogen atmosphere and then held for 3 minutes (the weight loss relative to the sample mass at the time of weight stabilization is referred to as "water"), then 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 weight loss relative to the sample mass is calculated, and the value obtained by subtracting a certain amount of water is referred to as "volatile components"), then cooled to 815°C at a rate of 30°C / min, and the weight loss relative to the sample mass after switching from a nitrogen atmosphere to an oxygen atmosphere and holding for 30 minutes is calculated, and the weight loss relative to the sample mass after subtracting a certain amount of water and volatile components is referred to as the fixed carbon rate.

[0021] The solid material in the present invention has a carboxyl functional group. It is speculated that the functional group undergoes a chemical reaction due to the mechanochemical effect, the carbon fixation rate increases, and a carboxyl group is generated. The solid material has a carboxyl group, for example, the carboxyl group is ionized in the soil, and combines with fertilizer components such as Mg ions, and as a result, the affinity with the soil becomes good. In addition, when the solid material is fixed to a substance, the carboxyl group acts to improve the affinity, and becomes a material with excellent dispersibility. Therefore, the carbon storage material composed of the solid material can be spread in the soil or fixed on the substance.

[0022] It should be noted that, for example, the presence of a carboxyl group in the solid material of the present invention can be confirmed by measuring an infrared absorption spectrum using a Fourier transform infrared spectrophotometer. Specifically, the solid material is added to KBr for adjustment, mixed in a mortar until uniform, and the resulting mixture is processed into granules. The infrared absorption spectrum is obtained using a Fourier transform infrared spectrophotometer FT / IR-6100 (manufactured by JASCO Corporation). The 3300-2500 cm -1 The absorption peak of is judged to be derived from the carboxyl functional group, and its presence is evaluated. Alternatively, it can be confirmed by solid 13C-NMR measurement.

[0023] The average diameter of the solid material in the present invention is 1 μm or more and 1000 μm or less, preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 300 μm or less. Due to this average diameter, the solid material can be directly 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, so the solid material can be fixed in the substance for a long time.

[0024] It should be noted that the average particle size measurement in the present invention can be confirmed by measuring, for example, a particle size distribution meter using a laser diffraction scattering method. Specifically, LMS-2000e (manufactured by SEISHIN ENTERPRISE Co., Ltd.) is used to measure the volume average particle size of the solid material using a wet method (ethanol solvent), and the diameter of the particles corresponding to the central cumulative value is set as the average diameter according to the cumulative curve of the particle size distribution of the volume average particle size.

[0025] The solid material in the present invention is preferably insoluble in water. Insoluble here means that the solid material will not be extracted as an aqueous solution when washed with water. If the solid material is insoluble in water, the decomposition of the solid material is difficult to proceed, and there is a tendency to be able to maintain it for a long time even when it is fixed to the ground or in a material.

[0026] The solid material in the present invention preferably shows a peak at 650°C or more and 840°C or less in differential thermal analysis. This peak originates from the recombination of hydrocarbon fragments belonging to flame-retardant carbon components, etc., and it is easy to maintain the solid material in a more stable state. It should be noted that the analysis can be measured by differential thermal analysis using a differential thermal thermogravimetric analysis Q-600 device (manufactured by TAinstruments). Specifically, 10 mg of a solid sample can be measured from room temperature to 1000°C at a heating rate of 30°C / min in a nitrogen atmosphere, and the exothermic peak detected at 650°C or more and 840°C or less is confirmed.

[0027] [First embodiment]

[0028] Next, use Figure 1 The method for producing a solid material according to the first embodiment will be described. A biomass raw material containing at least one of cellulose and lignin is subjected to a coarse pulverization step 1 and a heat pulverization step 2 to become a solid material.

[0029] The biomass raw material used in the present embodiment is coarsely pulverized in the coarse pulverization step 1. It is preferably pulverized into about 1 mm to 10 mm by the coarse pulverization step 1. In the coarse pulverization step 1, a pulverization method corresponding to the form of the biomass raw material can be selected, for example, a general-purpose pulverizer such as a hammer mill, a shredder, a vibration mill, a ball mill, a rod mill, a roller mill, a colloid mill, a disc mill, a jet mill, etc. can be used. In addition, the pulverization treatment in the coarse pulverization step 1 can be selected from any of the dry and wet methods, but dry pulverization is preferred in terms of reducing the crystallinity of cellulose and lignin. When the water content of the raw material is high, dry pulverization is performed after the water content is reduced to less than 30% by mass by centrifugal dehydration, hot air drying, etc., thereby effectively reducing the crystallinity of cellulose and lignin.

[0030] The coarsely pulverized biomass raw material used in the present embodiment is subjected to a heating and pulverizing treatment in the heating and pulverizing step 2. The biomass raw material is heated and carbonized, thereby increasing the proportion of fixed carbon and becoming a carbon compound material. As described above, fixed carbon refers to carbon in a stable state calculated as the mass of combustibles remaining at high temperature and in an oxygen-free state. The generation of such a carbon compound material is usually carried out by subjecting the biomass raw material to the so-called "steaming". However, most of the carbon contained in the biomass raw material is discharged into the atmosphere as carbon dioxide when combined with oxygen by heating. In addition, in the past, the production of high-quality carbon compound materials with a high fixed carbon rate required high-temperature and long-term heating of the biomass raw material, and thus, if a carbon compound material was generated, sometimes the amount of carbon dioxide generated was large and the yield was low. On the other hand, if the biomass raw material is heated at a low temperature and for a long time in order to reduce the amount of carbon dioxide generated, there are problems such as high yield but only low-grade carbon compound materials. That is, there is a trade-off relationship between the amount of carbon dioxide generated and the grade of the carbon compound material, i.e., the fixed carbon rate.

[0031] Therefore, in the heating and crushing process 2, a ball mill is used to perform heating and crushing treatment under heating at 100°C or above and below 300°C. It should be noted that the biomass raw material can also be buried in the soil or fixed to the material to keep the solid material in its shape, so it is heated and crushed to an average diameter of 1 μm or above and 1000 μm or below. The rotation speed is preferably in the range of more than 300rpm and 2000rpm. The higher the rotation speed, the easier it is to carbonize, but from the perspective of balancing the manufacturing energy and the load of the device, it is preferably more than 500rpm and less than 2000rpm, and more preferably more than 1000rpm and less than 2000rpm, so that the solid material can be obtained most effectively. The atmosphere in the heating and crushing process 2 can be normal pressure or vacuum, or it can be any atmosphere selected from oxygen, nitrogen, argon and rare gas.

[0032] Furthermore, by using a ball mill to heat and grind at a temperature of 100°C or higher and lower than 300°C, the mechanochemical effect of heating and grinding can be obtained to promote the decomposition of the biomass raw material. That is, the biomass raw material is decomposed into components such as cellulose, hemicellulose, and lignin by hydrolysis, and the molecular motion of cellulose and the like becomes active due to the friction heat and reaction heat of the ball mill, and the decrease in crystallinity and the depolymerization are accelerated, and further, another reaction occurs, and molecular repolymerization and cyclization reactions proceed, thereby presumably obtaining a solid material with a high fixed carbon rate.

[0033] The heating and pulverizing treatment is preferably carried out for more than 0.5 hours. The longer the time, the more reactions such as repolymerization proceed, so it is preferably treated for a long time, but in order to effectively obtain a solid material, it is preferably treated for about 0.5 hours to 5 hours. As described above, by obtaining a mechanochemical effect, the carbonization of the biomass raw material can be carried out at a low temperature and in a short time, so high-quality solid materials can be obtained by a simple method compared to the past. In addition, no solvent or catalyst is used in the heating and pulverizing step 2, so it is safe in the carbonization process and can reduce manufacturing costs.

[0034] It should be noted that the heating method is not particularly limited, and the container can be heated using an electric heater, high frequency, microwave, steam, etc. In addition, the pulverization can also be performed by a ball mill such as a planetary ball mill. If a ball mill is used, the ball is subjected to a large gravitational acceleration relative to the biomass raw material, so the mechanochemical effect brought about by the pulverization can be greatly increased, and the biomass raw material can be carbonized in a short time. The heating pulverization process can be performed under normal pressure or under vacuum.

[0035] [Second embodiment]

[0036] Figure 2This is a process flow chart of a method for producing a solid material according to a second embodiment. After a biomass raw material containing at least one of cellulose or lignin is subjected to a coarse pulverization step 1 and a heating pulverization step 2 to become a pulverized product, a water-soluble component is extracted in an extraction step 3. The other structures are the same as those of the first embodiment, and therefore a detailed description of the structures that are the same as those of the first embodiment is omitted.

[0037] The pulverized material subjected to the heat pulverization treatment in the heat pulverization step 2 contains monosaccharides or polysaccharides that become the raw materials of biomass fuel. They are water-soluble components and can therefore be extracted with water. In the past, the solubilization of biomass raw materials containing cellulose was carried out by generating a hydrolysis reaction in the subcritical region or supercritical region of water. According to the present embodiment, by passing through the heat pulverization step 2 and the extraction step 3, the treatment can be carried out at a low temperature and in a short time. In addition, without using a solvent or a catalyst, the solubilization and carbonization of the biomass raw materials can be carried out in a simple manner, so the manufacturing energy is small and the process is safe. Furthermore, the saccharification residue can be obtained as a solid material that can be used as a carbon storage material, etc., so there is no need to carry out a process for treating the saccharification residue after the biomass raw materials are solubilized.

[0038] In the present embodiment, the heat pulverization treatment can be performed for about 0.5 hour to 5 hours.

[0039] In the extraction step 3, water is preferably added in an amount of 0.1 to 500 times the amount of the pulverized product obtained in the heating pulverization step 2, and mixed, and solid-liquid separation is performed using a solid-liquid separation device to obtain a solubilized solution and a solid material as a saccharification residue. Examples of the solid-liquid separation device include devices using a gravity sedimentation method, a centrifugal separation method, a membrane separation method, a coagulation separation method, a flotation separation method, and the like.

[0040] The solubilized solution obtained in the extraction step 3 can be mixed with a solid acid catalyst and stirred to be hydrolyzed to produce a saccharified liquid containing monosaccharides such as glucose as a main component. By fermenting and distilling the saccharified liquid thus obtained, ethanol can be obtained as a biomass fuel.

[0041] The water-insoluble saccharification residue in the extraction step 3 can be obtained as a solid material. The solid material is directly used as a carbon compound material for a carbon storage material, or the carbon compound material is molded and processed to make a carbon storage material. The solid material obtained in this way is a by-product of biomass fuel production, and thus leads to a reduction in carbon dioxide emissions in life cycle assessment.

[0042] [Example]

[0043] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the description of these examples. First, the evaluation methods of various characteristics used in the present examples will be specifically described.

[0044] (1) Evaluation of fixed carbon rate

[0045] For 10 mg of the solid material, a thermogravimetric analysis Q-500 device (manufactured by TAinstruments) was used to heat the sample from room temperature at a rate of 30°C / min to 107°C in a nitrogen atmosphere and then hold it for 3 minutes (the reduction in weight relative to the sample mass at the time of weight stabilization was defined as "water"). 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 then held for 3 minutes (the reduction in weight relative to the sample mass was calculated, and the value obtained by subtracting a certain amount of water was defined as "volatile components"), and then the temperature was lowered to 815°C at a rate of 30°C / min, and the reduction in weight relative to the sample mass after switching from a nitrogen atmosphere to an oxygen atmosphere and holding it for 30 minutes was calculated, and the value obtained by subtracting a certain amount of water and volatile components was calculated as the fixed carbon content. The numerical value was calculated to 1 decimal place, and the first decimal place was rounded off.

[0046] (2) Solubility evaluation

[0047] For the solid material, water in an amount 10 times the mass of the solid material was used to visually confirm whether or not the solid material was not extracted as an aqueous solution during washing and remained as a solid component.

[0048] (3) Differential thermal analysis

[0049] For 10 mg of the solid material, a differential thermal analysis curve was obtained by heating from room temperature to 1000° C. at a heating rate of 30° C. / min in a nitrogen atmosphere using a differential thermal analysis and thermogravimetric analysis Q-600 device (manufactured by TAinstruments). It should be noted that based on the database of differential thermal analysis curves of forest felled materials described in "Hirohisa Yoshida / Nobuyuki Koga, Thermal Analysis 4th Edition, p.243-245, Kodansha Science", a characteristic exothermic peak associated with the development of a condensed aromatic ring structure is attributed at 650° C. or higher and 840° C. or lower.

[0050] (4) Evaluation of carboxyl functional groups

[0051] The solid material was added to KBr for adjustment and mixed in a mortar until uniform. The obtained mixture was processed into granules and the infrared absorption spectrum was obtained using a Fourier transform infrared spectrophotometer FT / IR-6100 (manufactured by JASCO Corporation). -1 The absorption peak was judged to be derived from the carboxyl functional group, and its presence was evaluated.

[0052] (5) Average diameter measurement

[0053] The volume average particle size of the solid material was measured by a wet method (ethanol solvent) using a particle size distribution analyzer LMS-2000e (manufactured by Seishin Enterprise Co., Ltd.) using a laser diffraction scattering method. From the cumulative curve of the volume average particle size distribution, the diameter of the particle corresponding to the central cumulative value was taken as the average diameter.

[0054] (Example 1)

[0055] A cellulose reagent "Avicel" (registered trademark) PH-101 (Merck) was heat-pulverized using a ball mill equipped with a heater (ball 5 mmφ) at 200°C for 1.5 hours and 800 to 1600 rpm. After heat-pulverization, the obtained solid material was naturally cooled and then subjected to various evaluations.

[0056] like Figure 3 As shown, the fixed carbon ratio of the obtained solid material was 50%. In differential thermal analysis, the exothermic peak was detected at 650°C or higher and 840°C or lower. The peak was measured at 3300-2500cm by Fourier transform infrared spectrophotometer. -1 The absorption peak was detected with an average diameter of 20 μm.

[0057] (Example 2)

[0058] A solid material was produced in the same manner as in Example 1 except that the heat pulverization treatment was performed at 170° C. for 3 hours.

[0059] The fixed carbon ratio of the obtained solid material was 29%. The exothermic peak was detected at 650°C or higher and 840°C or lower in differential thermal analysis, and the peak was measured at 3300-2500cm by Fourier transform infrared spectrophotometer. -1 The absorption peak was detected and the average diameter was 24 μm.

[0060] (Comparative Example 1)

[0061] A solid material was produced in the same manner as in Example 1 except that the conditions for the heat pulverization treatment were changed to 200° C., 6 hours, and 300 rpm.

[0062] The fixed carbon ratio of the obtained solid material was 6%. In addition, the Fourier transform infrared spectrophotometer was used to measure the carbon content of the solid material at 3300 to 2500 cm -1 However, in the differential thermal analysis, no exothermic peak was confirmed at 650° C. or higher and 840° C. or lower. The average diameter was 35 μm.

[0063] (Comparative Example 2)

[0064] A cellulose reagent "Avicel" (registered trademark) PH-101 (manufactured by Merck) was heat-treated in an electric furnace heated to 200° C. for 1.5 hours. After heating, the obtained solid material was naturally cooled in the same manner as in Example 1, and various evaluations were performed.

[0065] The fixed carbon ratio of the obtained solid material was 3%. In addition, in differential thermal analysis, no exothermic peak was confirmed at 650° C. or higher and 840° C. or lower. The average diameter was 43 μm.

[0066] All the solid materials of Examples 1 and 2 can achieve a fixed carbon ratio of 20% or more. On the other hand, the production conditions of Comparative Example 1 are equivalent to Example 1 described in Japanese Patent Application Laid-Open No. 2013-111034, and the fixed carbon ratio does not reach 20% despite the heating and pulverization time being longer than that of Example 1. In addition, in Comparative Example 2 heated by an electric furnace, the fixed carbon ratio is greatly reduced to 3% even if the heating time is the same as that of Example 1.

[0067] In the above-mentioned embodiment, the following structure can be derived.

[0068] (1) A carbon compound material comprising a solid material composed of a biomass raw material containing at least one of cellulose and lignin, the solid material having a carboxyl group, a fixed carbon rate of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

[0069] Biomass raw materials containing at least one of cellulose or lignin are not easy to decompose as described above, and the saccharification residue after extracting sugar is not effectively utilized. Most of these biomass raw materials and saccharification residues are used as solid fuels. If they are burned, the carbon dioxide absorbed by the plants is released into the atmosphere. However, the fixed carbon rate of the carbon compound material in this structure is more than 20%, thereby enabling long-term and stable storage of carbon. Therefore, the carbon dioxide absorbed by the plants can be retained in the carbon compound material without being released into the atmosphere, and a state in which the amount of carbon dioxide absorbed is more than the amount of carbon dioxide emitted (carbon negative) can be achieved. In addition, since the average diameter is more than 1 μm and less than 1000 μm, the solid material can be buried in the soil as a fine powder and the solid material can be mixed with the substance. Furthermore, since it has a carboxyl group, it is possible to provide a material with a low environmental load type with high environmental affinity. Thus, cellulose-based biomass and its saccharification residue can be effectively utilized to achieve carbon negative.

[0070] (2) In the carbon compound material described in (1), the solid material is preferably insoluble in water.

[0071] The water-soluble components (the parts that become sugars) in the biomass raw materials are used as biomass fuel, but the water-insoluble components are mostly discarded as saccharification residues. According to this structure, the saccharification residues can be effectively used as carbon storage materials, thereby reducing the amount of waste by-products when producing biomass fuel.

[0072] (3) In the carbon compound material described in (1) or (2), it is preferred that the solid material shows a peak at 650° C. or higher and 840° C. or lower in differential thermal analysis.

[0073] It is speculated that the peak at 650°C or higher and 840°C or lower in differential thermal analysis is obtained by repolymerization of low-molecular hydrocarbon species obtained by decomposing cellulose and lignin, which are the main components of the biomass raw materials. Since such components have a high carbon content, carbon compound materials that show an exothermic peak in differential thermal analysis in this temperature range are useful as carbon storage materials.

[0074] (4) A carbon storage material comprising the carbon compound material according to any one of (1) to (3).

[0075] According to this structure, carbon can be stably stored for a long period of time, and a carbon storage material with high environmental affinity can be provided.

[0076] (5) A method for producing a carbon compound material, comprising: a coarse grinding step 1, wherein a biomass raw material containing at least one of cellulose or lignin is coarsely ground; and a heating grinding step 2, wherein the coarsely ground biomass raw material is heated and ground, wherein the heating grinding step 2 is carried out using a ball mill under heating at a temperature above 100°C and below 300°C.

[0077] Biomass raw materials become carbon compound materials by increasing the proportion of fixed carbon through thermal decomposition. Such carbon compound materials are produced by subjecting the biomass raw materials to so-called "steaming". However, if the carbon contained in the biomass raw materials is combined with oxygen by heating, it is discharged into the atmosphere as carbon dioxide. In the past, the production of high-grade carbon compound materials required high-temperature and long-term heating of the biomass raw materials. When carbon compound materials were produced in this way, sometimes the amount of carbon dioxide produced was large and the yield was low. In addition, if the biomass raw materials are heated at low temperature and for a long time in order to reduce the amount of carbon dioxide produced, there are problems such as only low-grade carbon compound materials can be obtained although the yield is high. That is, there is a trade-off relationship between the amount of carbon dioxide produced and the grade of the carbon compound material, that is, the fixed carbon rate.

[0078] However, by carrying out a method for producing a carbon compound material having a coarse pulverization step 1 and a heating pulverization step 2 as in the present structure, the amount of carbon dioxide generated can be reduced, and a high-quality carbon compound material can be obtained at a high yield. In the coarse pulverization step 1, the biomass raw material can be in a shape that is easy to handle. In addition, in the heating pulverization step 2, the molecular motion of cellulose or lignin is activated by heating, and the cellulose or lignin can be amorphized and the molecular weight can be reduced by pulverization, so that the biomass raw material can be carbonized at a low temperature and in a short time by a mechanochemical effect. In particular, in the present structure, the heating pulverization step 2 is carried out using a ball mill under low oxygen atmosphere and at a relatively low temperature of 100°C or more and less than 300°C, so the generation of carbon dioxide accompanying oxidation can be suppressed, and a high-quality carbon compound material can be obtained at a high yield. In addition, since no solvent or catalyst is used, the manufacturing process is simple, the energy load during manufacturing is also small, and the environmental affinity of the generated carbon compound material is also high. Furthermore, carbon compound materials can also be obtained from biomass raw materials other than wood by this structure, so it is useful as a negative emission technology.

[0079] (6) In the process for producing a carbon compound material as described in (5), the heating and pulverizing step 2 is preferably performed at a rotation speed exceeding 300 rpm and less than 2000 rpm.

[0080] According to this configuration, the higher the rotation speed in the heating and pulverizing step 2, the easier it is for carbonization to proceed, and thus a solid material can be obtained efficiently.

[0081] (7) In the process for producing a carbon compound material as described in (5) or (6), it is preferred that the process further comprises an extraction step 3 of extracting a water-soluble component of the solid material obtained in the heating and pulverizing step 2 with water.

[0082] By having the extraction step 3 of extracting the water-soluble component of the carbon compound material with water, the water-soluble component can be used as a biomass fuel. In addition, by using the residue after extraction as a carbon compound material, carbon dioxide emissions in life cycle assessment can be reduced, so that the biomass raw material can be effectively utilized.

[0083] Other Implementations

[0084] (1) In the above embodiment, the heating and pulverizing is performed at 100°C to 300°C for 0.5 to 5 hours. However, the solubility of the biomass raw material may be measured in advance, and the heating and pulverizing treatment may be performed at a reaction time and reaction temperature at which the solubility is maximized.

[0085] (2) A carbon compound material can be produced by mixing a fertilizer component or the like with the solid material obtained by the implementation of the present invention and granulating the mixture. In this way, the carbon compound material can function not only as a carbon storage material but also as a soil improvement material or fertilizer.

[0086] [Industrial Availability]

[0087] The present invention can be used for a carbon compound material capable of effectively utilizing saccharification residues, a carbon storage material containing the carbon compound material, and a method for producing the carbon compound material.

Claims

1. A carbon compound material comprising a solid material composed of a biomass raw material containing at least one of cellulose and lignin, The solid material has a carboxyl group, a fixed carbon rate of 20% or more, and an average diameter of 1 μm or more and 1000 μm or less.

2. The carbon compound material according to claim 1, wherein The solid material is insoluble in water.

3. The carbon compound material according to claim 1, wherein The solid material shows a peak at 650° C. or higher and 840° C. or lower 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 method for producing a carbon compound material, comprising: a coarse pulverization step of coarsely pulverizing a biomass raw material containing at least one of cellulose or lignin; and a heating and pulverizing step of heating and pulverizing the roughly pulverized biomass raw material; The heat pulverization step is performed by 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: In the heating and pulverizing step, the rotation is performed at a speed exceeding 300 rpm and less than 2000 rpm.

7. The method for producing a carbon compound material according to claim 5 or 6, wherein: The method further comprises an extraction step of extracting a water-soluble component of the solid material obtained in the heating and pulverizing step using water.

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