WO2023100814A1 - Solid biofuel from two-stage semi-carbonization step, and method for manufacturing same - Google Patents

Solid biofuel from two-stage semi-carbonization step, and method for manufacturing same Download PDF

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Publication number
WO2023100814A1
WO2023100814A1 PCT/JP2022/043791 JP2022043791W WO2023100814A1 WO 2023100814 A1 WO2023100814 A1 WO 2023100814A1 JP 2022043791 W JP2022043791 W JP 2022043791W WO 2023100814 A1 WO2023100814 A1 WO 2023100814A1
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pressure
molding
raw material
semi
solid biofuel
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PCT/JP2022/043791
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French (fr)
Japanese (ja)
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高広 村上
諭 水野
徹 澤井
民男 井田
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国立研究開発法人産業技術総合研究所
学校法人近畿大学
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Publication of WO2023100814A1 publication Critical patent/WO2023100814A1/en

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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L5/00—Solid fuels
    • C10L5/40—Solid fuels essentially based on materials of non-mineral origin
    • C10L5/44—Solid fuels essentially based on materials of non-mineral origin on vegetable substances
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/10—Biofuels, e.g. bio-diesel
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Definitions

  • the present invention relates to a method for producing a solid biofuel comparable to bituminous coal from lignite from plant-derived biomass.
  • Biomass is biogenic organic matter that can be used as a raw material or fuel. Examples include wood, dried plants, agricultural waste, livestock waste, food and beverage waste, organic sludge such as initial settling sludge and excess sludge in biological wastewater treatment facilities and sewage treatment plants, and its dehydrated sludge. correspond to
  • biomass-based fuels such as those described above as alternative fuels, or partial alternative fuels, to petroleum and coal.
  • biomass is highly effective in reducing CO 2 emissions from the viewpoint of carbon neutrality, and its use is recommended worldwide.
  • biomass solid fuel is manufactured by semi-carbonizing biomass, it has a higher volatile content than coal, and therefore a lower fuel ratio (fixed carbon content/volatile content).
  • coal grades are divided into anthracite, bituminous coal, and lignite.
  • anthracite is 4.0 or more
  • bituminous coal is 1.5 or more and less than 1.5
  • lignite is 1.0. It is stated below.
  • biomass solid fuel is about 0.8 (Patent Document 1).
  • the fuel ratio is low, the ignitability will be high, but the combustion time will be short and the shape retention during combustion will be low.
  • the combustion time will be short and the shape retention during combustion will be low.
  • it When used as a substitute for coal-coke or as a mixture with coal-coke in a blast furnace, it must fall from the top of the blast furnace to the bottom while burning. I don't want it to burn out.
  • the present invention provides a solid biofuel that is produced entirely from biomass and has a fuel ratio that exceeds that of lignite.
  • the solid biofuel according to the invention is A solid biofuel obtained by compacting at least one or more chips of biomass resulting from photosynthesis, and having a fuel ratio of 0.4 or more and 2.0 or less and a density of 1.0 g. /cm 3 or more.
  • the method for producing a solid biofuel includes: A first stage step of obtaining a semi-carbonized raw material by semi-carbonizing the raw material obtained by chipping the biomass resulting from photosynthesis and releasing a part of the moisture and volatile matter in the raw material; A heating and pressurizing step of obtaining a heated and pressurized product by heating and pressurizing the semi-carbonized raw material while constantly renewing the maximum pressure; A molding step of molding the heated and pressurized product for a predetermined time while constantly renewing the maximum pressure to obtain a molded product; The method is characterized by comprising a second stage step of obtaining a compacted product by a cooling step of cooling the molded product while maintaining the pressure applied to the molded product at the start of cooling.
  • the solid biofuel according to the present invention is obtained by semi-carbonizing a biomass raw material to obtain a semi-carbonized raw material, and then heating it while constantly renewing the maximum pressure to proceed with the semi-carbonizing process in a two-step process. It has characteristics such as a fuel ratio exceeding 0.4 and a density of 1.0 g/cm 3 or more. This fuel ratio value is comparable to that of lignite to bituminous coal, and has the effect of being able to burn for a longer period of time than conventional solid biofuels. In addition, since the density is 1.0 g/cm 3 or more, it is possible to suppress the situation that the blast furnace collapses or is blown away by the combustion wind blowing up during the fall of the blast furnace.
  • the method for producing a solid biofuel according to the present invention produces a solid biofuel through a two-stage carbonization process consisting of a first-stage process of semi-carbonizing a biomass raw material and a second-stage process of compaction molding accompanied by semi-carbonization. do.
  • a fuel ratio exceeding 0.4 that is, a solid biofuel equivalent to bituminous coal can be obtained from lignite. This value is not achievable with the solid biofuel produced by the conventional manufacturing method shown in WO 2006/078023, and can burn for a longer period of time.
  • 1 is a graph showing temperature and pressure processes in a solid biofuel production method according to the present invention.
  • 2 is a graph showing another embodiment of the heating and pressurizing step in FIG. 1; It is a graph which shows a heating pressurization process when an initial pressure is less than 30 MPa.
  • 4 is a graph showing a case where pressure is forcibly applied from the initial pressure to the molding start pressure.
  • 10 is a graph showing a heating and pressurizing process in which pressure is forcibly applied at first and the maximum pressure is renewed in the middle.
  • 4 is a graph showing the fuel ratio in each step of the solid biofuel production method according to the present invention. 4 is a graph showing changes in fuel ratio with and without the first step.
  • 5 is a graph showing the difference in density when the pre-semi-carbonized raw material is pressurized and then heated, when the pre-semi-carbonized raw material is heated and pressurized, and when the semi-carbonized raw material is heated and pressurized.
  • biomass resulting from photosynthesis uses only biomass resulting from photosynthesis as a raw material.
  • biomass can be considered as a general definition of "renewable organic resources derived from living organisms, excluding fossil resources”.
  • biomass resulting from photosynthesis includes biomass such as woods, herbs, agricultural crops, and kitchen waste.
  • woody materials trees, dead leaves or their wastes such as forest residues, pruning/leaf cutting materials, driftwood, paper, etc. can be suitably used.
  • bamboo, kenaf and the like can be suitably used as herbs.
  • non-edible parts such as psyllium stalks, sesame stalks, potato vines, and rice husks can be suitably used.
  • kitchen waste coffee grounds, used tea leaves, bean curd refuse, and the like can be suitably used.
  • the raw material is in a pre-semi-carbonized state.
  • the raw material is cut into a predetermined size. Specifically, it is preferably several tens of ⁇ m to several cm. This may be called a step of chipping biomass as a raw material.
  • the raw material obtained in this manner is “a raw material obtained by chipping biomass resulting from photosynthesis” and can be said to be a raw material in a “pre-semi-carbonized state”. Hereinafter, it is simply referred to as “biomass raw material”.
  • the biomass raw material is subjected to semi-carbonization.
  • the semi-carbonization step is a temperature treatment that does not cause carbonization sufficiently, and may be considered a temperature treatment of about 400° C. or less.
  • heat treatment is added. A temperature of 200° C. to 300° C. can be suitably used for the heat treatment.
  • the biomass raw material When the biomass raw material reaches the target temperature, it is held for a certain period of time. The holding time was preferably about 1 minute to 60 minutes. After the constant temperature is maintained, it is cooled to room temperature.
  • the cooling method There is no particular limitation on the cooling method. It may be natural cooling, forced cooling, or cooling using a refrigerant.
  • the fuel ratio of the material to be treated (biomass raw material that has undergone the first-stage process) is at least higher than the fuel ratio of the raw material before semi-carbonization.
  • the product from the first step is referred to as the "semi-carbonized feedstock”.
  • the semi-carbonized raw material is compression-molded while being further semi-carbonized.
  • the semi-carbonized raw material filled in a predetermined mold hereinafter also referred to as a "molding space"
  • a device for heating while pressurizing the semi-carbonized raw material filled in a predetermined space is used.
  • 190 to 300 degreeC is suitably used for the process temperature here.
  • the semi-carbonized raw material is put into a molding space (molding chamber of a molding apparatus) that can be pressurized and heated, and heated to a molding start temperature Tt (for example, 190 ° C.) under the condition that the initial loading pressure ILP (Initial Loading Pressure) is 8 MPa or more. do.
  • the pressure at the molding start temperature is the molding start pressure Pt.
  • the molding start pressure Pt is set higher than the initial pressure ILP.
  • a temperature increase rate Trup of about 10° C./min is usually used, but the temperature increase rate is not limited to this.
  • a molding start temperature Tt of 190° C. to 300° C. is preferably used.
  • the method of heating and pressurizing while constantly renewing the maximum pressure is a method in which when the raw material expands due to heating and the pressure in the molding space increases, heating is performed without lowering the pressure below the increased pressure. .
  • the pressure a very short time ago is set as the maximum pressure Pm, and if the current pressure is higher than Pm, the current pressure is set as the new maximum pressure Pm.
  • the molding device is controlled so that the maximum pressure Pm is always applied to the molding space. Therefore, the volume of the molding space may remain constant, provided that heating causes the temperature of the raw material to rise, thereby increasing the pressure in the molding space.
  • the minute time may be determined by the machine time of the molding apparatus, and a range of 0.01 to 3 seconds, for example, can be suitably used.
  • the pressurization operation in the heating and pressurizing process may forcefully increase the pressure in the molding space at a predetermined pressurization rate. For example, if it is desired to heat the raw material in the molding space of a certain volume and increase the pressure in the molding space faster than the pressure rises due to heating, the heating can be performed while forcibly pressurizing.
  • forcible pressurization means that a force is applied in the direction of forcibly reducing the molding space.
  • the boost rate at this time is not limited to the linear proportional relationship between time and pressure.
  • the boost rate may be such that the pressure increases quadratically with respect to time.
  • the pressurizing operation in the heating and pressurizing step may be performed by combining a method of heating and pressurizing while always updating the maximum pressure and a method of heating and pressurizing while forcibly pressurizing.
  • heating and pressurization may be performed while forcibly pressurizing until the middle of the temperature rise, and pressurization and heating may be performed while updating the maximum pressure from the middle.
  • the semi-carbonized raw material that has been heated and pressurized until the molding process, which will be described later, is started is called a heated and pressurized product.
  • the molding start pressure Pt is a value higher than 30 MPa, or a pressure that allows the maximum molding pressure Pmx to exceed 30 MPa in the molding process described later.
  • the pressure higher than the initial pressure ILP is called back pressure (BP). It is also necessary to have a back pressure in the method for producing solid biofuel according to the invention. In other words, the molding start pressure Pt is higher than the initial pressure ILP regardless of the procedure of the heating and pressurizing process.
  • the molding space is held for a predetermined time while constantly renewing the maximum pressure. It can be said that the heated and pressurized product is held for a predetermined time while constantly renewing the maximum pressure.
  • the pressure in the molding space in the molding process is called "molding pressure”.
  • the molding pressure may be understood as the pressure applied to the heated and pressurized product in the molding space.
  • the highest pressure during the molding process is called the “maximum molding pressure Pmx”. Since pressure control is performed while constantly updating the maximum pressure, the maximum molding pressure Pmx is the pressure at the final point of the molding process (at the start of the cooling process, which will be described later).
  • the "predetermined time”, which is the time for the molding process, is preferably from one minute to several hours. Also, the “predetermined time” may be referred to as “molding time”.
  • the molding time is a preset time.
  • the temperature of the molding space in the molding process is called the "molding temperature".
  • the molding temperature may be interpreted as the temperature of the heated and pressurized product in the molding space.
  • the molding temperature is usually controlled so as to maintain the molding start temperature Tt.
  • the molding temperature may be forced to change (heating or cooling by the molding apparatus) during the molding time.
  • the temperature in the molding space the temperature of the hot and pressurized product
  • it may be cooled to a constant temperature, or the increased temperature Temperature control may be performed to keep the .
  • the molding pressure is always controlled to update the maximum pressure even if the molding temperature changes.
  • a heated and pressurized product in the molding space that has undergone the molding process is called a molded product.
  • ⁇ Cooling process> In the molding process, when the molding time elapses from the start of molding, the process moves to the cooling process. In the cooling process, the temperature in the molding space (the temperature of the molded product) is lowered at a predetermined rate.
  • the molded product is cooled while maintaining the size of the molding space (volume: volume of the molded product) at the start of cooling.
  • the molded product decreases in volume as the temperature decreases.
  • the pressure on the molding space is also reduced.
  • cooling is performed while the pressure is controlled so that the volume of the molding space is at least equal to or less than the volume of the molding space at the start of cooling. That is, in the cooling process, the molding space is controlled to be smaller than the molding space at the start of cooling so that the molding space at the start of cooling is maintained or pressure is applied to the molded product.
  • the molding apparatus is controlled so as to reduce the volume of the molding space in order to compensate for the pressure reduction that accompanies the volume reduction of the molded product due to the temperature drop.
  • the molded product after the cooling process is the compacted product, which is the solid biofuel.
  • FIG. 1 specifically shows the steps described above. It can be said that FIG. 1 represents the operation program of the molding apparatus.
  • the horizontal axis represents time (which may be elapsed time)
  • the left vertical axis represents the temperature of the molding space (temperature of the object to be processed)
  • the right vertical axis represents the pressure of the molding space (temperature of the object to be processed). pressure).
  • As the unit of temperature “°C: Celsius” or “K: Kelvin” is preferably used.
  • MPa can be suitably used as the unit of pressure.
  • the time t0 is the processing start time.
  • the initial temperature Ts at the normal processing start time is room temperature.
  • the molding apparatus heats up to Tt, which is a molding start temperature, at time t2, maintains temperature Tt from time t2 to time t4, and then cools at a constant temperature drop rate until time t5. That is, from time t0 to time t2 is the heating and pressurizing process, from time t2 to time t4 is the molding process, and from time t4 to time t5 is the cooling process.
  • FIG. 1 shows that the temperature of the pre-semi-carbonized raw material in the molding space rises from time t1, which is in the middle of the heating and pressurizing step, and the pressure rises.
  • the volume of the molding space is adjusted so as to constantly update the maximum pressure. Since most pre-sintering raw materials expand in volume when heated, the molding space only needs to retain the volume at the initial pressure ILP. However, when the volume of the raw material before semi-carbonization temporarily decreases due to heating, the pressure is controlled so that the volume of the molding space decreases in order to compensate for the pressure decrease due to the volume decrease.
  • the transition from the heating and pressurizing process to the molding process depends on whether or not the molding start temperature Tt has been reached. be judged. This is because, in this case, the molding start pressure Pt is, so to speak, a pressure depending on the course of events.
  • the pressure at time t2 is the molding start pressure Pt.
  • pressure control is performed so as to always update the maximum pressure.
  • the inside of the molded article expands due to the conditions of heating and pressurization, the pressure in the molding space increases.
  • FIG. 1 shows that such a change occurred at time t3.
  • the molding space is controlled so that the molding pressure is always updated to the maximum pressure, so the pressure once increased is maintained as the maximum pressure. That is, even if the volume of the molded product is subsequently reduced, the molding space is controlled to be small so that the pressure is maintained.
  • the molding space is controlled so that pressure is applied to the raw material during heating, so the molding start pressure Pt is always greater than the initial pressure ILP (back pressure: BP).
  • FIG. 1 shows an example in which the molding temperature in the molding process is controlled to maintain the molding start temperature Tt.
  • the molding temperature may be forcibly changed.
  • the molding process is managed by time. That is, the time between time t2 and time t4 is set in advance.
  • the pressure at the start of cooling is the maximum molding pressure Pmx.
  • Pmx the maximum molding pressure
  • the pressure in the molding space decreases as the volume of the molded product decreases or the internal pressure of the molded product decreases.
  • This pressure reduction is called "molding space constant cooling".
  • cooling is performed while applying a pressure equal to or higher than the constant cooling of the molding space.
  • a decompression line in the molding space (a line indicating the relationship between time and pressure in the molding space) should be present in the gray area. If there is a decompression line in this region, it can be said that the molding space is cooled at a pressure that makes the volume of the molding space less than that of the molding space at the start of cooling.
  • FIG. 1 it is a decompression line represented by reference numeral 12 .
  • Reference numeral 10 denotes a decompression line representing constant cooling of the molding space.
  • the decompression line 12 is adjusted in the molding space so that the maximum molding pressure Pmx is maintained until just before the temperature is cooled to around room temperature (Ts in FIG. 1) and the process is completed. Then, the load is unloaded at once at the processing end time (time t5). It should be noted that cooling while controlling the molding space so as to maintain the maximum molding pressure Pmx does not mean cooling while constantly renewing the maximum pressure.
  • decompression line 12 in addition to the decompression line 12, if it is a gray area, other decompression lines may be passed (for example, decompression lines 14, 16, etc.).
  • cooling may be performed while applying a pressure equal to or higher than the maximum molding pressure Pmx at the start of cooling (eg, decompression line 18).
  • the white arrow indicates that the pressure may be equal to or higher than the maximum molding pressure Pmx.
  • Fig. 2 shows one form of the heating and pressurizing process.
  • the maximum molding pressure Pmx must be greater than 30 MPa, which is achieved by setting the initial pressure ILP to 30 MPa or more. Further, as shown in FIG. 3, even if the initial pressure ILP is less than 30 MPa, the initial pressure ILP may be lower than 30 MPa as long as it can exceed 30 MPa by the subsequent heating/pressurizing step and molding step. .
  • the pressurization in the heating and pressurizing step is the pressurization that is always performed so as to renew the maximum pressure. Therefore, the molding process is performed while applying back pressure.
  • FIG. 4 shows a case where pressure is forcibly applied from the initial pressure ILP to the molding start pressure.
  • the molding start pressure Pt is also set in advance, the molding start pressure can be reliably set to a pressure exceeding 30 MPa, and back pressure can also be applied.
  • the solid biofuel according to the present invention can be obtained with a fuel ratio of 0.4 to 2.0. Alternatively, it is possible to obtain a value of 0.7 to 2.0. Also, it may be possible to obtain a fuel ratio of 1.0 to 2.0.
  • the solid biofuel according to the present invention is formed by first semi-carbonizing a biomass raw material to obtain a semi-carbonized raw material, and then heating the semi-carbonized raw material while pressurizing it. Therefore, some volatiles are removed by the first-stage torrefaction treatment. Therefore, in the semi-carbonized molding step of the second step, the amount of volatilized volatile matter in the semi-carbonized raw material is small, and a solid biofuel with high density can be obtained by heating and pressurizing.
  • the solid biofuel according to the present invention preferably has a density of 1.0 g/cm 3 or more, more preferably 1.05 g/cm 3 or more. Since a higher density is preferable, there is no need to limit the upper limit.
  • the amount of CO 2 reduction when such solid biofuel is used as a 100% coal-coke alternative fuel in a 100 t/year scale coal-coke oven can be summarized as shown in the table.
  • Table 1 presents the assumptions for CO2 reduction estimates. Table 1 shows the numerical values for the case of using cedar as a biomass raw material and the combustion of coal-coke and natural gas. Next, the biomass raw material is converted into a solid biofuel through the first step (written as “pretreatment”) and the second step (written as “solidification”), and when the substitution rate is 100%, The total CO2 reduction is obtained from the CO2 reduction and the CO2 emissions used for solid biofuel production.
  • the raw material before semi-carbonization had a volatile content of 81.6%, a fixed carbon content of 18.0%, and an ash content of 0.40%. Therefore, the fuel ratio of the biomass feedstock was about 0.22.
  • the raw material before semi-carbonization was heated to 300°C at a heating rate of 10°C/min, and held for 5 minutes after reaching 300°C. After that, it was naturally cooled to room temperature to obtain a semi-carbonized raw material.
  • This semi-carbonized raw material is heated from room temperature to a set temperature of 107° C. at a rate of 10° C./min under an inert atmosphere using a thermobalance, held for 30 minutes after reaching the set temperature, and then raised to a set temperature of 900° C. at a rate of 10° C./min. It was heated and held for 10 minutes after reaching 900°C.
  • the weight loss indicated a reduction of about 30 points in volatiles in the pre-charred feedstock.
  • the fuel ratio of the semi-carbonized raw material was about 0.35, which was 0.13 higher than the fuel ratio of the biomass raw material (0.22).
  • the second stage process was performed as follows.
  • the semi-carbonized raw material obtained in the first step was filled in a ⁇ 4 mm cylindrical container.
  • the molding vessel was set in a solid biofuel manufacturing apparatus capable of heating under pressure, and a pressure of about 44 MPa was applied to the semi-carbonized raw material in the molding vessel as an initial compressive load. After that, it was heated to a set temperature of 280°C. During the temperature rising process, back pressure was applied, and when the target temperature of 280°C was reached, a compressive load exceeding the initial compressive load was applied to the sample in the molding container.
  • This solid biofuel is heated from room temperature to a set temperature of 107°C at a rate of 10°C/min in an inert atmosphere using a thermobalance, held for 30 minutes after reaching the set temperature, and then raised to a set temperature of 900°C at a rate of 10°C/min. It was heated and held for 10 minutes after reaching 900°C.
  • a measured value of about 1.15 was obtained.
  • the horizontal axis is the sample type and the vertical axis is the fuel ratio (unitless).
  • the fuel ratio of the raw material itself before semi-carbonization which was 0.22, became 0.35 when the raw material was semi-carbonized, and the fuel ratio improved to 1.15 when it became a solid biofuel.
  • Fig. 7 shows changes in the fuel ratio of a sample (comparative example) when the biomass raw material is directly solidified at 190°C without going through the semi-carbonization process of the first step.
  • this invention was made into the "Example.”
  • the horizontal axis is the sample type and the vertical axis is the fuel ratio.
  • the pre-semi-carbonized raw material was directly pressure-molded at 190°C.
  • the initial pressure during molding was about 44 MPa, which was the same as for the solid biofuel according to the present invention.
  • the pressure adjustment method is also the same. That is, back pressure occurs as in the case of the embodiment.
  • the fuel ratio of the comparative example improved from 0.2 (biomass raw material) to about 0.36 (after treatment).
  • the change in the fuel ratio of the solid biofuel obtained from the semi-carbonized raw material shown in FIG. 6 by the second step process is shown again.
  • the object of heating and pressurization is the raw material before semi-carbonization (comparative example) and the semi-carbonized raw material (example), and the molding temperature is 190 ° C. (comparative example) and 280 ° C. (example). It can be said that the difference is
  • the raw material before semi-carbonization is heat-treated while being pressurized, it cannot be compacted at a temperature of 280°C due to gasification.
  • the semi-carbonized raw material had a small amount of gasification, and compaction molding was possible even at a temperature of 280°C.
  • FIG. 8 shows the results of density measurements.
  • the horizontal axis is the sample type
  • the vertical axis is the density (g/cm 3 ).
  • the pre-semi-carbonized raw material was pressurized at room temperature at 44 MPa, heated without pressure, and molded at 190 ° C. (left end of the horizontal axis), and the pre-semi-carbonized raw material was directly subjected to 44 MPa and 190 ° C. (the center of the horizontal axis), and the semi-carbonized raw material was directly heated under the conditions of 44 MPa and 280° C. (right end of the horizontal axis).
  • the middle and rightmost samples correspond to the comparative example and example in FIG. 7, respectively.
  • the density improved (the center of the horizontal axis and the right end of the horizontal axis).
  • the pre-semi-carbonized raw material heated and pressed was higher than the half-carbonized raw material heated and pressed (right end of the horizontal axis).
  • the fuel ratio does not increase due to the presence of a large amount of volatile matter.
  • the solid biofuel according to the present invention can have a fuel ratio of more than 0.4 and a density of 1.0 g/cm 3 or more. Therefore, it can be suitably used as a substitute for or used in combination with coal coke, and can contribute to CO2 reduction.

Abstract

As a solid biofuel serving as an alternative or mix-in for coal coke, there is demand for a solid biofuel that has a high combustion ratio and is capable of long-term combustion and of maintaining form during combustion.　This solid biofuel is obtained using a manufacturing method including: a first-stage step in which a raw material that has been chipped from a biomass resulting from photosynthesis is subjected to semi-carbonization to obtain a semi-carbonized raw material in which some of the moisture and volatile content of said raw material is released; and a second-stage step in which the semi-carbonized raw material is heated and pressed to obtain a consolidated molded article. Said solid biofuel has a fuel ratio exceeding 0.4 and a density of 1.0 g/cm3 or greater, and can be used as a coal coke alternative and contribute to CO2 reduction.

Description

二段階半炭化工程による固体バイオ燃料およびその製造方法Solid biofuel by two-step semi-carbonization process and method for producing same
　本発明は、植物由来バイオマスから褐炭から瀝青炭に匹敵する固体バイオ燃料を製造する方法に関する。 The present invention relates to a method for producing a solid biofuel comparable to bituminous coal from lignite from plant-derived biomass.
　バイオマスは、原料、燃料として利用できる生物起源の有機物である。例えば、木材、乾燥草木、農産廃棄物、畜産廃棄物、食品・飲料廃棄物、生物学的廃水処理設備や下水処理場における初沈汚泥、余剰汚泥などの有機性汚泥やその脱水汚泥などがこれに該当する。 　Biomass is biogenic organic matter that can be used as a raw material or fuel. Examples include wood, dried plants, agricultural waste, livestock waste, food and beverage waste, organic sludge such as initial settling sludge and excess sludge in biological wastewater treatment facilities and sewage treatment plants, and its dehydrated sludge. correspond to
　近年では、石油や石炭などの代替燃料または一部代替燃料として、上記のようなバイオマスを用いた燃料の利用促進が図られている。特にバイオマスは、カーボンニュートラルの観点からＣＯ２排出削減には非常に効果的であるため、世界的に利用が推奨されている。 In recent years, efforts have been made to promote the use of biomass-based fuels such as those described above as alternative fuels, or partial alternative fuels, to petroleum and coal. In particular, biomass is highly effective in reducing CO 2 emissions from the viewpoint of carbon neutrality, and its use is recommended worldwide.
　バイオマス固体燃料は、バイオマスを半炭化処理されて製造されるため、石炭と比較し揮発分が多く、それゆえ燃料比（固定炭素量／揮発分量）が低い。例えば、石炭のグレードは、無煙炭、瀝青炭、褐炭と分けられるが、燃料比としては、無煙炭が４．０以上、瀝青炭は１．５以上と１．５未満のものにわかれ、褐炭は１．０以下とされている。それに対して、バイオマス固体燃料としては、０．８程度のものとされる（特許文献１）。 Because biomass solid fuel is manufactured by semi-carbonizing biomass, it has a higher volatile content than coal, and therefore a lower fuel ratio (fixed carbon content/volatile content). For example, coal grades are divided into anthracite, bituminous coal, and lignite. As for the fuel ratio, anthracite is 4.0 or more, bituminous coal is 1.5 or more and less than 1.5, and lignite is 1.0. It is stated below. On the other hand, biomass solid fuel is about 0.8 (Patent Document 1).
　燃料比が低いと、着火性は高くなるものの、燃焼時間は短くなり、燃焼中の形状維持性も低くなる。高炉において、石炭コークスの代替品若しくは石炭コークスとの混合品として用いる場合は、高炉上端から底に向かって燃焼しながら落下する必要があり、下方からの燃焼風で吹き上げられたり、落下の間に燃え尽きてしまうのは好ましくない。 If the fuel ratio is low, the ignitability will be high, but the combustion time will be short and the shape retention during combustion will be low. When used as a substitute for coal-coke or as a mixture with coal-coke in a blast furnace, it must fall from the top of the blast furnace to the bottom while burning. I don't want it to burn out.
特開２０２０－９０６７３号公報JP 2020-90673 A
　石炭コークスの代替品もしくは混合品としての固体バイオ燃料としては、燃料比が高く、長時間の燃焼と、燃焼中の形状維持が可能な固体バイオ燃料が求められている。また、固体バイオ燃料が、高炉の投入口から供給する際には、炉底まで崩壊せずに燃焼しながら落下することが望まれる。本発明はバイオマスだけで製造され、燃料比が褐炭を超えるような値を有する固体バイオ燃料を提供する。 As a coal-coke substitute or solid biofuel as a mixture, there is a demand for a solid biofuel that has a high fuel ratio, can burn for a long time, and can maintain its shape during combustion. Moreover, when the solid biofuel is supplied from the inlet of the blast furnace, it is desirable that it falls to the bottom of the furnace while burning without collapsing. The present invention provides a solid biofuel that is produced entirely from biomass and has a fuel ratio that exceeds that of lignite.
　より具体的に本発明に係る固体バイオ燃料は、
　光合成に起因するバイオマスをチップ化した原料だけを用い、前記原料を少なくとも１個以上押し固めた固体バイオ燃料であって、燃料比が０．４以上２．０以下であり、密度が１．０ｇ／ｃｍ３以上であることを特徴とする。 More specifically, the solid biofuel according to the invention is
A solid biofuel obtained by compacting at least one or more chips of biomass resulting from photosynthesis, and having a fuel ratio of 0.4 or more and 2.0 or less and a density of 1.0 g. /cm 3 or more.
　また本発明に係る固体バイオ燃料の製造方法は、
　光合成に起因するバイオマスをチップ化した原料を、半炭化処理し、前記原料中の水分・揮発分の一部を放出させる半炭化済原料を得る第一段工程と、
　前記半炭化済原料を常に最大圧力を更新しながら加熱加圧し加熱加圧品を得る加熱加圧工程と、
　前記加熱加圧品に、常に最大圧力を更新しながら所定時間成型し、成型品を得る成型工程と、
　冷却開始時の前記成型品にかかる圧力を維持した状態で、前記成型品を冷却する冷却工程によって圧密成型物を得る第二段工程を有することを特徴とする。 Further, the method for producing a solid biofuel according to the present invention includes:
A first stage step of obtaining a semi-carbonized raw material by semi-carbonizing the raw material obtained by chipping the biomass resulting from photosynthesis and releasing a part of the moisture and volatile matter in the raw material;
A heating and pressurizing step of obtaining a heated and pressurized product by heating and pressurizing the semi-carbonized raw material while constantly renewing the maximum pressure;
A molding step of molding the heated and pressurized product for a predetermined time while constantly renewing the maximum pressure to obtain a molded product;
The method is characterized by comprising a second stage step of obtaining a compacted product by a cooling step of cooling the molded product while maintaining the pressure applied to the molded product at the start of cooling.
　本発明に係る固体バイオ燃料は、バイオマスの原料を半炭化させ半炭化済原料を得た後、さらに常に最大圧力を更新しながら加熱し半炭化処理を進める二段階の工程を経ることによって得ることができ、燃料比が０．４を超え、密度が１．０ｇ／ｃｍ３以上の特性を有する。この燃料比の値は褐炭から瀝青炭に匹敵する燃料比であり、従来の固体バイオ燃料より、長時間燃焼させることができるという効果を奏する。また、密度が１．０ｇ／ｃｍ３以上であるので、高炉の落下中に吹き上げる燃焼風で崩壊する若しくは、飛ばされるという事態を抑制することができる。 The solid biofuel according to the present invention is obtained by semi-carbonizing a biomass raw material to obtain a semi-carbonized raw material, and then heating it while constantly renewing the maximum pressure to proceed with the semi-carbonizing process in a two-step process. It has characteristics such as a fuel ratio exceeding 0.4 and a density of 1.0 g/cm 3 or more. This fuel ratio value is comparable to that of lignite to bituminous coal, and has the effect of being able to burn for a longer period of time than conventional solid biofuels. In addition, since the density is 1.0 g/cm 3 or more, it is possible to suppress the situation that the blast furnace collapses or is blown away by the combustion wind blowing up during the fall of the blast furnace.
　本発明に係る固体バイオ燃料の製造方法は、バイオマスの原料を半炭化処理させる第一段工程、半炭化処理を伴い圧密成型させる第二段工程からなる二段階炭化工程により、固体バイオ燃料を製造する。本製造方法で製造することで、燃料比が０．４を超える、すなわち褐炭から瀝青炭相当の固体バイオ燃料を得ることができる。この値は、国際公開第２００６／０７８０２３号に示される従来の製造法による固体バイオ燃料では達成できなかった値であり、より長時間燃焼することができる。 The method for producing a solid biofuel according to the present invention produces a solid biofuel through a two-stage carbonization process consisting of a first-stage process of semi-carbonizing a biomass raw material and a second-stage process of compaction molding accompanied by semi-carbonization. do. By producing by this production method, a fuel ratio exceeding 0.4, that is, a solid biofuel equivalent to bituminous coal can be obtained from lignite. This value is not achievable with the solid biofuel produced by the conventional manufacturing method shown in WO 2006/078023, and can burn for a longer period of time.
本発明に係る固体バイオ燃料の製造方法において、温度および圧力のプロセスを示すグラフである。1 is a graph showing temperature and pressure processes in a solid biofuel production method according to the present invention. 図１における加熱加圧工程の他の実施形態を示すグラフである。2 is a graph showing another embodiment of the heating and pressurizing step in FIG. 1; 初期圧力が３０ＭＰａ未満の場合の加熱加圧工程を示すグラフである。It is a graph which shows a heating pressurization process when an initial pressure is less than 30 MPa. 初期圧力から成型開始圧力まで強制的に圧力が加えられた場合を示すグラフである。4 is a graph showing a case where pressure is forcibly applied from the initial pressure to the molding start pressure. 最初は強制的に圧力を加え、途中から最大圧力を更新するような加熱加圧工程を示すグラフである。10 is a graph showing a heating and pressurizing process in which pressure is forcibly applied at first and the maximum pressure is renewed in the middle. 本発明に係る固体バイオ燃料の製造方法の各工程における燃料比を示したグラフである。4 is a graph showing the fuel ratio in each step of the solid biofuel production method according to the present invention. 第一段工程を経た場合と経ない場合の燃料比の変化を示したグラフである。4 is a graph showing changes in fuel ratio with and without the first step. 半炭化前原料を加圧し、次に加熱した場合、半炭化前原料を加熱加圧した場合、半炭化済原料を加熱加圧した場合の密度の違いを示すグラフである。5 is a graph showing the difference in density when the pre-semi-carbonized raw material is pressurized and then heated, when the pre-semi-carbonized raw material is heated and pressurized, and when the semi-carbonized raw material is heated and pressurized.
　以下に本発明に係る固体バイオ燃料および固体バイオ燃料の製造方法について図面および実施例を示し説明を行う。なお、以下の説明は、本発明の一実施形態および一実施例を例示するものであり、本発明が以下の説明に限定されるものではない。以下の説明は本発明の趣旨を逸脱しない範囲で改変することができる。 The solid biofuel and the solid biofuel production method according to the present invention will be described below with reference to drawings and examples. In addition, the following description illustrates one embodiment and one example of the present invention, and the present invention is not limited to the following description. The following description can be modified without departing from the spirit of the invention.
　本発明に係る固体バイオ燃料は、光合成に起因するバイオマスだけを原料とする。ここでバイオマスとは、「再生可能な生物由来の有機性資源で化石資源を除いたもの」という一般的な定義と考えてよい。また、「光合成に起因するバイオマス」とは、木質類、草本類、農作物類、厨芥類などのバイオマスがあげられる。 The solid biofuel according to the present invention uses only biomass resulting from photosynthesis as a raw material. Here, biomass can be considered as a general definition of "renewable organic resources derived from living organisms, excluding fossil resources". In addition, "biomass resulting from photosynthesis" includes biomass such as woods, herbs, agricultural crops, and kitchen waste.
　木質類としては、木、枯葉またはその廃棄物である林地残渣、剪定・葉刈り材、流木、紙などが好適に利用できる。草本類としては、竹、ケナフなどが好適に利用できる。農作物類としては、オオバ茎、ゴマ茎、芋つる、籾殻といった、非食部位が好適に利用できる。厨芥類としては、コーヒー滓、茶殻、オカラ等が好適に利用できる。 As woody materials, trees, dead leaves or their wastes such as forest residues, pruning/leaf cutting materials, driftwood, paper, etc. can be suitably used. Bamboo, kenaf and the like can be suitably used as herbs. As agricultural products, non-edible parts such as psyllium stalks, sesame stalks, potato vines, and rice husks can be suitably used. As kitchen waste, coffee grounds, used tea leaves, bean curd refuse, and the like can be suitably used.
　また、本発明に係る固体バイオ燃料は、原料が半炭化前状態にされている。 Also, in the solid biofuel according to the present invention, the raw material is in a pre-semi-carbonized state.
　＜チップ化工程＞
　まず、原料は、所定の大きさに裁断される。具体的には、数十μｍから数ｃｍ程度であるのが好ましい。これは、原料となるバイオマスをチップ化する工程と呼んでよい。また、このようにして得た原料は、「光合成に起因するバイオマスをチップ化した原料」であり、「半炭化前状態」の原料ということができる。以下単に「バイオマス原料」とも呼ぶ。 <Chipping process>
First, the raw material is cut into a predetermined size. Specifically, it is preferably several tens of μm to several cm. This may be called a step of chipping biomass as a raw material. In addition, the raw material obtained in this manner is “a raw material obtained by chipping biomass resulting from photosynthesis” and can be said to be a raw material in a “pre-semi-carbonized state”. Hereinafter, it is simply referred to as “biomass raw material”.
　＜半炭化工程（第一段工程）＞
　バイオマス原料は、半炭化処理が施される。なお、半炭化工程とは、十分に炭化させない程度の温度処理であり、４００℃程度以下の温度処理と考えてよい。具体的には、加熱処理が加えられる。加熱処理の温度は、２００℃から３００℃が好適に利用することができる。 <Semi-carbonization process (first stage process)>
The biomass raw material is subjected to semi-carbonization. Note that the semi-carbonization step is a temperature treatment that does not cause carbonization sufficiently, and may be considered a temperature treatment of about 400° C. or less. Specifically, heat treatment is added. A temperature of 200° C. to 300° C. can be suitably used for the heat treatment.
　バイオマス原料が、目標温度に達したら一定時間保持を行う。保持時間は１分から６０分程度が好適であった。一定温度保持が終了したら常温まで冷却させる。冷却の方法は特に問わない。自然冷却であってもよいし、強制冷却であってもよいし、冷媒を用いた冷却でもよい。 When the biomass raw material reaches the target temperature, it is held for a certain period of time. The holding time was preferably about 1 minute to 60 minutes. After the constant temperature is maintained, it is cooled to room temperature. There is no particular limitation on the cooling method. It may be natural cooling, forced cooling, or cooling using a refrigerant.
　この第一段工程の半炭化工程によって、被処理物（第一段工程を経たバイオマス原料）の燃料比は、少なくとも半炭化前状態の原料の燃料比よりも向上する。第一段工程による生成物を「半炭化済原料」と呼ぶ。 Due to the semi-carbonization process of the first-stage process, the fuel ratio of the material to be treated (biomass raw material that has undergone the first-stage process) is at least higher than the fuel ratio of the raw material before semi-carbonization. The product from the first step is referred to as the "semi-carbonized feedstock".
　＜半炭化成型工程（第二段工程）＞
　次に半炭化済原料をさらに半炭化処理を行いながら圧縮成型する。この第二段工程では、所定の成型型（以後「成型空間」とも呼ぶ。）に充填された半炭化済原料は、加熱加圧工程、成型工程、冷却工程の各工程が順に施される。したがって、所定の空間に充填された半炭化済原料を加圧しながら加熱する装置が用いられる。以下に各工程を詳説する。なお、ここでの処理温度は１９０℃から３００℃が好適に用いられる。 <Semi-carbonizing process (second stage process)>
Next, the semi-carbonized raw material is compression-molded while being further semi-carbonized. In this second step, the semi-carbonized raw material filled in a predetermined mold (hereinafter also referred to as a "molding space") is subjected to each step of heating and pressing, molding, and cooling in order. Therefore, a device for heating while pressurizing the semi-carbonized raw material filled in a predetermined space is used. Each step will be described in detail below. In addition, 190 to 300 degreeC is suitably used for the process temperature here.
　＜加熱加圧工程＞
　半炭化済原料を、加圧・加熱できる成型空間（成型装置の成型室）に投入し、初期圧力ＩＬＰ（Ｉｎｉｔｉａｌ　Ｌｏａｄｉｎｇ　Ｐｒｅｓｓｕｒｅ）が８ＭＰａ以上の条件で、成型開始温度Ｔｔ（例えば１９０℃）まで加熱する。成型開始温度の時の圧力が成型開始圧力Ｐｔである。成型開始圧力Ｐｔは初期圧力ＩＬＰより高い圧力にする。昇温レートＴｒｕｐは１０℃／分程度が通常利用されるが、この昇温レートに限定されない。成型開始温度Ｔｔは１９０℃から３００℃が好適に用いられる。 <Heating and pressurizing process>
The semi-carbonized raw material is put into a molding space (molding chamber of a molding apparatus) that can be pressurized and heated, and heated to a molding start temperature Tt (for example, 190 ° C.) under the condition that the initial loading pressure ILP (Initial Loading Pressure) is 8 MPa or more. do. The pressure at the molding start temperature is the molding start pressure Pt. The molding start pressure Pt is set higher than the initial pressure ILP. A temperature increase rate Trup of about 10° C./min is usually used, but the temperature increase rate is not limited to this. A molding start temperature Tt of 190° C. to 300° C. is preferably used.
　加熱加圧工程における加圧では、常に最大圧力を更新しながら加熱加圧する方法が用いられる。「常に最大圧力を更新しながら加熱加圧する方法」とは、加熱によって原料が膨張し、成型空間内の圧力が高くなったら、高くなった圧力より低い圧力にすることなく加熱を行う方法である。 For pressurization in the heating and pressurizing process, a method of heating and pressurizing while constantly updating the maximum pressure is used. "The method of heating and pressurizing while constantly renewing the maximum pressure" is a method in which when the raw material expands due to heating and the pressure in the molding space increases, heating is performed without lowering the pressure below the increased pressure. .
　より具体的には、微小時間前の圧力を最大圧力Ｐｍとし、現在の圧力がＰｍより高ければ、現在の圧力を新たな最大圧力Ｐｍとする。そして、成型装置は常に最大圧力Ｐｍが成型空間にかかるように制御される。したがって、加熱によって原料の温度が上昇し、それによって成型空間の圧力が上昇するのであれば、成型空間の体積は一定のままでよい。 More specifically, the pressure a very short time ago is set as the maximum pressure Pm, and if the current pressure is higher than Pm, the current pressure is set as the new maximum pressure Pm. The molding device is controlled so that the maximum pressure Pm is always applied to the molding space. Therefore, the volume of the molding space may remain constant, provided that heating causes the temperature of the raw material to rise, thereby increasing the pressure in the molding space.
　しかし、微小時間前の最大圧力Ｐｍより圧力が減少するようなことがあれば、成型空間の体積を減少させ、微小時間前の最大圧力Ｐｍを維持するように成型装置は動作する。すなわち、常に最大圧力が維持されるように成型空間の体積が調節される。なお、ここで微小時間は、成型装置のマシンタイムで決めてよく、例えば０．０１秒から３秒の範囲が好適に利用できる。 However, if the pressure decreases from the maximum pressure Pm before the minute time, the volume of the molding space is reduced and the molding apparatus operates to maintain the maximum pressure Pm before the minute time. That is, the volume of the molding space is adjusted so that the maximum pressure is always maintained. Here, the minute time may be determined by the machine time of the molding apparatus, and a range of 0.01 to 3 seconds, for example, can be suitably used.
　加熱加圧工程における加圧動作は、所定の昇圧レートで強制的に成型空間の圧力を上昇させてもよい。例えば、一定体積の成型空間内の原料を加熱し、加熱によって上昇する圧力よりも早く成型空間の圧力を高くしたい場合は、強制的な加圧を行いながら加熱することができる。なお、ここで強制的な加圧とは成型空間を強制的に小さくする方向に力が加わることである。また、この際の昇圧レートは、時間と圧力の直線的な比例関係だけに限定されない。例えば、時間に対して圧力が２次関数的に増加するような昇圧レートであってもよい。 The pressurization operation in the heating and pressurizing process may forcefully increase the pressure in the molding space at a predetermined pressurization rate. For example, if it is desired to heat the raw material in the molding space of a certain volume and increase the pressure in the molding space faster than the pressure rises due to heating, the heating can be performed while forcibly pressurizing. Here, forcible pressurization means that a force is applied in the direction of forcibly reducing the molding space. Also, the boost rate at this time is not limited to the linear proportional relationship between time and pressure. For example, the boost rate may be such that the pressure increases quadratically with respect to time.
　また、加熱加圧工程における加圧動作は、常に最大圧力を更新しながら加熱加圧する方法と、強制的に加圧しながら加熱加圧する方法を組み合わせてもよい。例えば、昇温の途中までは、常に強制的に加圧しながら加熱加圧し、途中からは最大圧力を更新しながら加圧加熱してもよい。後述する成型工程が開始されるまで加熱加圧された半炭化済原料を加熱加圧品と呼ぶ。 In addition, the pressurizing operation in the heating and pressurizing step may be performed by combining a method of heating and pressurizing while always updating the maximum pressure and a method of heating and pressurizing while forcibly pressurizing. For example, heating and pressurization may be performed while forcibly pressurizing until the middle of the temperature rise, and pressurization and heating may be performed while updating the maximum pressure from the middle. The semi-carbonized raw material that has been heated and pressurized until the molding process, which will be described later, is started is called a heated and pressurized product.
　なお、本発明に係る固体バイオ燃料の製造方法では、後述する「最大成型圧力Ｐｍｘ」が３０ＭＰａより高い値で成型されたものである。したがって、成型開始圧力Ｐｔは、３０ＭＰａより高い値であるか、後述する成型工程で、最大成型圧力Ｐｍｘが３０ＭＰａを超えることができるような圧力である。また、加熱加圧工程および後述する成型工程において、初期圧力ＩＬＰより高くなる圧力をバックプレッシャー（ＢＰ）と呼ぶ。本発明に係る固体バイオ燃料の製造方法では、バックプレッシャーを有することも必要である。つまり、加熱加圧工程がどのような手順で行われても、成型開始圧力Ｐｔは初期圧力ＩＬＰより高くなる。 In addition, in the solid biofuel manufacturing method according to the present invention, the "maximum molding pressure Pmx", which will be described later, is molded at a value higher than 30 MPa. Therefore, the molding start pressure Pt is a value higher than 30 MPa, or a pressure that allows the maximum molding pressure Pmx to exceed 30 MPa in the molding process described later. In addition, in the heating/pressurizing process and the molding process described later, the pressure higher than the initial pressure ILP is called back pressure (BP). It is also necessary to have a back pressure in the method for producing solid biofuel according to the invention. In other words, the molding start pressure Pt is higher than the initial pressure ILP regardless of the procedure of the heating and pressurizing process.
　＜成型工程＞
　成型開始温度Ｔｔに到達したら、常に最大圧力を更新しながら、所定時間の間、成型空間を保持する。加熱加圧品を常に最大圧力を更新しながら、所定時間の間保持するといってもよい。ここで、成型工程における成型空間の圧力を「成型圧力」と呼ぶ。成型圧力は成型空間内の加熱加圧品にかかる圧力と解してよい。 <Molding process>
When the molding start temperature Tt is reached, the molding space is held for a predetermined time while constantly renewing the maximum pressure. It can be said that the heated and pressurized product is held for a predetermined time while constantly renewing the maximum pressure. Here, the pressure in the molding space in the molding process is called "molding pressure". The molding pressure may be understood as the pressure applied to the heated and pressurized product in the molding space.
　「常に最大圧力を更新しながら」とは、＜加熱加圧工程＞での説明と同様である。すなわち、微小時間前の圧力を最大圧力Ｐｍとし、現在の圧力がＰｍより高ければ、現在の圧力を新たな最大圧力Ｐｍとする。そして、成型装置は常に最大圧力Ｐｍが成型空間にかかるように成型空間の体積を制御する。 "Always updating the maximum pressure" is the same as the explanation in <Heating and pressurizing process>. That is, the pressure a minute time ago is set as the maximum pressure Pm, and if the current pressure is higher than Pm, the current pressure is set as the new maximum pressure Pm. The molding apparatus controls the volume of the molding space so that the maximum pressure Pm is always applied to the molding space.
　成型工程の間で最も圧力が大きい圧力を「最大成型圧力Ｐｍｘ」と呼ぶ。常に最大圧力を更新しながら圧力制御が行われるので、最大成型圧力Ｐｍｘは、成型工程の最終時点（後述する冷却工程の開始時）の圧力である。 　The highest pressure during the molding process is called the "maximum molding pressure Pmx". Since pressure control is performed while constantly updating the maximum pressure, the maximum molding pressure Pmx is the pressure at the final point of the molding process (at the start of the cooling process, which will be described later).
　成型工程の時間である「所定時間」は、１分乃至数時間程度が好適に採用される。また、「所定時間」は「成型時間」といってもよい。成型時間はあらかじめ設定される時間である。 The "predetermined time", which is the time for the molding process, is preferably from one minute to several hours. Also, the "predetermined time" may be referred to as "molding time". The molding time is a preset time.
　成型工程における成型空間の温度を「成型温度」と呼ぶ。成型温度は成型空間内の加熱加圧品の温度と解してよい。成型温度は通常成型開始温度Ｔｔを維持するように制御される。しかし、成型時間の間、成型温度を強制的に（成型装置が加熱若しくは冷却して）変化させてもよい。また、加熱加圧品の内部に発熱が生じ、成型空間内の温度（加熱加圧品の温度）が上昇した場合、それを一定の温度にするように冷却してもよいし、上昇した温度をそのまま維持するように温度制御が行われてもよい。ただし、本発明に係る固体バイオ燃料の製造方法においては、成型温度に変化があっても、成型圧力は常に最大圧力を更新するように制御される。成型工程を経た成型空間内の加熱加圧品を成型品と呼ぶ。 　The temperature of the molding space in the molding process is called the "molding temperature". The molding temperature may be interpreted as the temperature of the heated and pressurized product in the molding space. The molding temperature is usually controlled so as to maintain the molding start temperature Tt. However, the molding temperature may be forced to change (heating or cooling by the molding apparatus) during the molding time. In addition, when heat is generated inside the hot and pressurized product and the temperature in the molding space (the temperature of the hot and pressurized product) rises, it may be cooled to a constant temperature, or the increased temperature Temperature control may be performed to keep the . However, in the solid biofuel manufacturing method according to the present invention, the molding pressure is always controlled to update the maximum pressure even if the molding temperature changes. A heated and pressurized product in the molding space that has undergone the molding process is called a molded product.
　成型工程において、常に最大圧力を更新することで、熱伝導による加熱が足りず、成型品内部の温度が低い場合でも、軟化による樹脂化を発現させることができるという効果を奏する。加えて、最大成型圧力Ｐｍｘを長時間（６０分程度）維持すれば、熱伝導により成型品内部の温度が上昇し、成型品内部の大部分を軟化・樹脂化させることができるという効果も奏する。これらの効果は、成型品が冷却され固体バイオ燃料となった際にも残る。 By constantly updating the maximum pressure in the molding process, even if the temperature inside the molded product is low due to insufficient heating due to heat conduction, it has the effect of being able to soften and become resinous. In addition, if the maximum molding pressure Pmx is maintained for a long period of time (about 60 minutes), the temperature inside the molded product rises due to heat conduction, and there is an effect that most of the inside of the molded product can be softened and resinified. . These effects remain even when the molding is cooled to become a solid biofuel.
　＜冷却工程＞
　成型工程において成型開始から成型時間が経過したら、冷却工程に移る。冷却工程では成型空間内の温度（成型品の温度）を所定のレートで降下させる。 <Cooling process>
In the molding process, when the molding time elapses from the start of molding, the process moves to the cooling process. In the cooling process, the temperature in the molding space (the temperature of the molded product) is lowered at a predetermined rate.
　冷却工程では、急激な除荷は成型品に割れを生じさせるため好ましくない。冷却開始時の成型空間の大きさ（体積：成型品の体積）を維持したまま、成型品の冷却が行われる。成型品は温度が下がるにつれ体積が減少する。その結果成型空間にかかる圧力も減少する。本発明における冷却工程では、成型空間の体積が、少なくとも冷却開始時の成型空間以下になるように圧力が制御されながら冷却が行われる。すなわち、冷却工程においては、成型空間は、冷却開始時の成型空間を維持するか、もしくは成型品に圧力がかかるように冷却開始時の成型空間より小さくなるように制御される。 　In the cooling process, sudden unloading is not preferable because it causes cracks in the molded product. The molded product is cooled while maintaining the size of the molding space (volume: volume of the molded product) at the start of cooling. The molded product decreases in volume as the temperature decreases. As a result, the pressure on the molding space is also reduced. In the cooling step of the present invention, cooling is performed while the pressure is controlled so that the volume of the molding space is at least equal to or less than the volume of the molding space at the start of cooling. That is, in the cooling process, the molding space is controlled to be smaller than the molding space at the start of cooling so that the molding space at the start of cooling is maintained or pressure is applied to the molded product.
　特に、冷却開始時の成型空間の圧力（最大成型圧力Ｐｍｘ）を維持したまま冷却するのは好ましい。このような冷却では、温度低下による成型品の体積減少に伴う圧力減少を補償するため、成型空間の体積を減少させるように成型装置は制御される。冷却工程が終了した成型品は圧密成型物であり、これが固体バイオ燃料である。 In particular, it is preferable to cool while maintaining the pressure in the molding space (maximum molding pressure Pmx) at the start of cooling. In such cooling, the molding apparatus is controlled so as to reduce the volume of the molding space in order to compensate for the pressure reduction that accompanies the volume reduction of the molded product due to the temperature drop. The molded product after the cooling process is the compacted product, which is the solid biofuel.
　＜グラフによる説明＞
　図１に上記の説明の工程を具体的に示す。図１は成型装置の運転プログラムを表しているともいえる。図１を参照して、横軸は時刻（経過時間としてもよい。）であり、左縦軸は成型空間の温度（被処理物の温度）、右縦軸は成型空間の圧力（被処理物にかかる圧力）を示す。温度の単位は「℃：摂氏」若しくは「Ｋ：ケルビン」が好適に用いられる。圧力の単位はＭＰａが好適に利用できる。 <Explanation by graph>
FIG. 1 specifically shows the steps described above. It can be said that FIG. 1 represents the operation program of the molding apparatus. Referring to FIG. 1, the horizontal axis represents time (which may be elapsed time), the left vertical axis represents the temperature of the molding space (temperature of the object to be processed), and the right vertical axis represents the pressure of the molding space (temperature of the object to be processed). pressure). As the unit of temperature, "°C: Celsius" or "K: Kelvin" is preferably used. MPa can be suitably used as the unit of pressure.
　時刻ｔ０は処理開始時刻である。通常処理開始時刻における初期温度Ｔｓは常温である。成型装置は、時刻ｔ２に成型開始温度であるＴｔまで加温し、時刻ｔ２から時刻ｔ４まで温度Ｔｔを維持し、その後時刻ｔ５まで一定の降温レートで冷却する。つまり、時刻ｔ０から時刻ｔ２までが加熱加圧工程であり、時刻ｔ２から時刻ｔ４までが成型工程であり、時刻ｔ４から時刻ｔ５までが冷却工程である。 The time t0 is the processing start time. The initial temperature Ts at the normal processing start time is room temperature. The molding apparatus heats up to Tt, which is a molding start temperature, at time t2, maintains temperature Tt from time t2 to time t4, and then cools at a constant temperature drop rate until time t5. That is, from time t0 to time t2 is the heating and pressurizing process, from time t2 to time t4 is the molding process, and from time t4 to time t5 is the cooling process.
　処理開示時刻ｔ０において、成型空間には初期圧力ＩＬＰが載荷されている。図１では、加熱加圧工程の途中である時刻ｔ１から成型空間内の半炭化前原料の温度が上昇し、圧力が高くなっていることを示している。加熱加圧工程では、常に最大圧力を更新するように、成型空間の体積が調節される。ほとんどの半炭化前原料は加熱によって体積が膨張するので、成型空間は初期圧力ＩＬＰ時の体積を保持するだけでよい。しかし、加熱によって半炭化前原料の体積が一時的に減少する場合、体積減少による圧力減少を補償するために成型空間の体積が減少するように圧力が制御される。 At the processing start time t0, the initial pressure ILP is applied to the molding space. FIG. 1 shows that the temperature of the pre-semi-carbonized raw material in the molding space rises from time t1, which is in the middle of the heating and pressurizing step, and the pressure rises. In the heating and pressurizing process, the volume of the molding space is adjusted so as to constantly update the maximum pressure. Since most pre-sintering raw materials expand in volume when heated, the molding space only needs to retain the volume at the initial pressure ILP. However, when the volume of the raw material before semi-carbonization temporarily decreases due to heating, the pressure is controlled so that the volume of the molding space decreases in order to compensate for the pressure decrease due to the volume decrease.
　加熱加圧工程を常に最大圧力を更新するように成型空間が調節される方法で加圧する場合は、加熱加圧工程から成型工程に移行するのは、成型開始温度Ｔｔへ到達したか否かで判断される。この場合は、成型開始圧力Ｐｔは、いわば成り行きによる圧力になるからである。 When the heating and pressurizing process is pressurized by a method in which the molding space is adjusted so as to constantly update the maximum pressure, the transition from the heating and pressurizing process to the molding process depends on whether or not the molding start temperature Tt has been reached. be judged. This is because, in this case, the molding start pressure Pt is, so to speak, a pressure depending on the course of events.
　図１では、時刻ｔ２の時の圧力が成型開始圧力Ｐｔである。成型工程（時刻ｔ２から時刻ｔ４）においては、常に最大圧力を更新するように圧力制御が行われる。なお、加熱加圧の条件で、成型品内部で膨張する変化が生じた場合は、成型空間の圧力は上昇する。図１では時刻ｔ３において、そのような変化が生じたことを示している。 In FIG. 1, the pressure at time t2 is the molding start pressure Pt. In the molding process (from time t2 to time t4), pressure control is performed so as to always update the maximum pressure. In addition, when the inside of the molded article expands due to the conditions of heating and pressurization, the pressure in the molding space increases. FIG. 1 shows that such a change occurred at time t3.
　成型圧力は常に最大圧力を更新するように成型空間が制御されるので、一度上昇した圧力は最大圧力として維持される。すなわち、仮にその後成型品の体積が縮小しても、圧力が維持されるように成型空間は小さくなるように制御される。加熱加圧工程において、加熱の最中に原料に圧力がかかるように成型空間が制御されるので、成型開始圧力Ｐｔは必ず、初期圧力ＩＬＰより大きい圧力（バックプレッシャー：ＢＰ）となる。 The molding space is controlled so that the molding pressure is always updated to the maximum pressure, so the pressure once increased is maintained as the maximum pressure. That is, even if the volume of the molded product is subsequently reduced, the molding space is controlled to be small so that the pressure is maintained. In the heating and pressurizing step, the molding space is controlled so that pressure is applied to the raw material during heating, so the molding start pressure Pt is always greater than the initial pressure ILP (back pressure: BP).
　図１では、成型工程における成型温度は成型開始温度Ｔｔを維持するように制御されている例を示している。しかし、＜成型工程＞で説明したように、成型温度を強制的に変化させてもよい。 FIG. 1 shows an example in which the molding temperature in the molding process is controlled to maintain the molding start temperature Tt. However, as described in <Molding step>, the molding temperature may be forcibly changed.
　成型工程は時間で管理される。すなわち、時刻ｔ２から時刻ｔ４の間の時間は予め設定されている。 The molding process is managed by time. That is, the time between time t2 and time t4 is set in advance.
　成型工程が終了したら、冷却工程に移行する（時刻ｔ４から時刻ｔ５）。冷却開始時の圧力は最大成型圧力Ｐｍｘである。本発明はこの最大成型圧力Ｐｍｘが３０ＭＰａ以上であるように設定することで、燃料比が０．４を超える固体バイオ燃料を得ることができる。 After the molding process is completed, the process shifts to the cooling process (from time t4 to time t5). The pressure at the start of cooling is the maximum molding pressure Pmx. According to the present invention, by setting the maximum molding pressure Pmx to 30 MPa or more, a solid biofuel having a fuel ratio exceeding 0.4 can be obtained.
　冷却開始時の成型空間を維持したまま、冷却すると、成型品の体積減少若しくは成型品の内部圧力減少に従い成型空間の圧力は減少する。この圧力減少を「成型空間一定冷却」と呼ぶ。本発明では、成型空間一定冷却以上の圧力をかけながら冷却を行う。図１では、灰色の領域に、成型空間の減圧線（時間と成型空間の圧力の関係を示すライン）があればよい。この領域に減圧線があれば、冷却開始時の成型空間以下の体積の成型空間となる圧力で成型空間を冷却すると言える。 When cooling while maintaining the molding space at the start of cooling, the pressure in the molding space decreases as the volume of the molded product decreases or the internal pressure of the molded product decreases. This pressure reduction is called "molding space constant cooling". In the present invention, cooling is performed while applying a pressure equal to or higher than the constant cooling of the molding space. In FIG. 1, a decompression line in the molding space (a line indicating the relationship between time and pressure in the molding space) should be present in the gray area. If there is a decompression line in this region, it can be said that the molding space is cooled at a pressure that makes the volume of the molding space less than that of the molding space at the start of cooling.
　特に本発明では、冷却開始時の最大成型圧力Ｐｍｘを維持するように、成型空間を制御しながら冷却するのが好ましい形態として挙げられる。図１では、符号１２で表される減圧線である。なお、成型空間一定冷却を表す減圧線は符号１０で示した。減圧線１２は、温度が常温（図１ではＴｓ）付近まで冷却され処理が終了する直前まで最大成型圧力Ｐｍｘが維持されるように、成型空間が調節される。そして処理終了時刻（時刻ｔ５）に一気に除荷される。なお、最大成型圧力Ｐｍｘを維持するように成型空間を制御しつつ冷却するとは、常に最大圧力を更新しながら冷却するのではない。 Especially in the present invention, it is preferable to cool while controlling the molding space so as to maintain the maximum molding pressure Pmx at the start of cooling. In FIG. 1, it is a decompression line represented by reference numeral 12 . Reference numeral 10 denotes a decompression line representing constant cooling of the molding space. The decompression line 12 is adjusted in the molding space so that the maximum molding pressure Pmx is maintained until just before the temperature is cooled to around room temperature (Ts in FIG. 1) and the process is completed. Then, the load is unloaded at once at the processing end time (time t5). It should be noted that cooling while controlling the molding space so as to maintain the maximum molding pressure Pmx does not mean cooling while constantly renewing the maximum pressure.
　本発明においては、減圧線１２だけでなく、灰色の領域であれば、他の減圧線を経てもよい（例えば減圧線１４、１６等）。また冷却開始時の最大成型圧力Ｐｍｘ以上の圧力をかけながら冷却してもよい（減圧線１８等）。なお、冷却開始時の最大成型圧力Ｐｍｘ以上の減圧線の存在領域の上限は特になく、成型装置の限界であってよい。図では、白矢印で最大成型圧力Ｐｍｘ以上の圧力でもよいことを示した。 In the present invention, in addition to the decompression line 12, if it is a gray area, other decompression lines may be passed (for example, decompression lines 14, 16, etc.). Alternatively, cooling may be performed while applying a pressure equal to or higher than the maximum molding pressure Pmx at the start of cooling (eg, decompression line 18). There is no particular upper limit for the region where the decompression line exists above the maximum molding pressure Pmx at the start of cooling, and it may be the limit of the molding apparatus. In the figure, the white arrow indicates that the pressure may be equal to or higher than the maximum molding pressure Pmx.
　図２には加熱加圧工程の一形態を示す。本発明においては最大成型圧力Ｐｍｘが３０ＭＰａより大きいことが必要であるが、そのためには、初期圧力ＩＬＰが３０ＭＰａ以上に設定することで達成される。また、図３に示すように、初期圧力ＩＬＰが３０ＭＰａ未満であっても、その後の加熱加圧工程と成型工程によって３０ＭＰａを超えることができるのであれば、初期圧力ＩＬＰが３０ＭＰａより低くてもよい。いずれの場合も加熱加圧工程での加圧は常に最大圧力を更新するように行う加圧である。したがって、バックプレッシャーをかけながら成型工程が行われる。 Fig. 2 shows one form of the heating and pressurizing process. In the present invention, the maximum molding pressure Pmx must be greater than 30 MPa, which is achieved by setting the initial pressure ILP to 30 MPa or more. Further, as shown in FIG. 3, even if the initial pressure ILP is less than 30 MPa, the initial pressure ILP may be lower than 30 MPa as long as it can exceed 30 MPa by the subsequent heating/pressurizing step and molding step. . In any case, the pressurization in the heating and pressurizing step is the pressurization that is always performed so as to renew the maximum pressure. Therefore, the molding process is performed while applying back pressure.
　図４では、初期圧力ＩＬＰから成型開始圧力まで強制的に圧力を加える場合を示す。この場合は成型開始圧力Ｐｔも予め設定されているので、確実に成型開始圧力を、３０ＭＰａを超える圧力にすることができ、バックプレッシャーも付与することができる。 FIG. 4 shows a case where pressure is forcibly applied from the initial pressure ILP to the molding start pressure. In this case, since the molding start pressure Pt is also set in advance, the molding start pressure can be reliably set to a pressure exceeding 30 MPa, and back pressure can also be applied.
　図５では、加熱加圧工程の始めの部分（時刻ｔ０から時刻ｔ６まで）では、常に外部から強制的に圧力を加えるが、時刻ｔ６からは最大圧力を更新するように加圧を行っている場合を示す。本発明では、このように、強制的に加圧する方法と、常に最大圧力を更新しながら加圧する方法を組み合わせて、加熱加圧工程を実施してもよい。以上のような工程を経て、第二段工程は実施される。 In FIG. 5, at the beginning of the heating and pressurizing process (from time t0 to time t6), pressure is always forcibly applied from the outside, but from time t6, pressurization is performed so as to update the maximum pressure. indicate the case. In the present invention, the method of forcibly applying pressure and the method of applying pressure while constantly renewing the maximum pressure may be combined in the heating and pressurizing process. The second step is carried out through the steps described above.
　このように二段階の工程を経ることで燃料比が０．４を超える固体バイオ燃料を得ることができる。この値は褐炭から瀝青炭に匹敵し、高炉などで用いる石炭コークスの代替品の可能性や、石炭コークスとの併用品としての実用性も視野に入れることができる。なお、本発明に係る固体バイオ燃料は燃料比が０．４～２．０のものを得ることができる。若しくは０．７～２．０のものを得るとすることもできる。また、燃料比が１．０～２．０のものを得ることができるとしてもよい。 By going through this two-step process, it is possible to obtain a solid biofuel with a fuel ratio exceeding 0.4. This value is comparable to that of lignite to bituminous coal, and the possibility of a substitute for coal-coke used in blast furnaces, etc., and the practicality as a combined product with coal-coke can also be considered. The solid biofuel according to the present invention can be obtained with a fuel ratio of 0.4 to 2.0. Alternatively, it is possible to obtain a value of 0.7 to 2.0. Also, it may be possible to obtain a fuel ratio of 1.0 to 2.0.
　また、本発明に係る固体バイオ燃料は、バイオマス原料をまず半炭化し半炭化済原料を得て、その半炭化済原料を加圧しながら加熱する方法によって形成される。したがって、第一段階の半炭化処理によって、ある程度の揮発分は抜ける。そのため、第二段工程の半炭化成型工程では、半炭化済原料中の揮発分の揮発量は少なく、加熱・加圧することによって密度の高い固体バイオ燃料を得ることができる。 In addition, the solid biofuel according to the present invention is formed by first semi-carbonizing a biomass raw material to obtain a semi-carbonized raw material, and then heating the semi-carbonized raw material while pressurizing it. Therefore, some volatiles are removed by the first-stage torrefaction treatment. Therefore, in the semi-carbonized molding step of the second step, the amount of volatilized volatile matter in the semi-carbonized raw material is small, and a solid biofuel with high density can be obtained by heating and pressurizing.
　本発明に係る固体バイオ燃料の密度は１．０ｇ／ｃｍ３以上、より好ましくは１．０５ｇ／ｃｍ３以上であることが望ましい。密度は高い方が好ましいので、上限値について限定する必要はない。 The solid biofuel according to the present invention preferably has a density of 1.0 g/cm 3 or more, more preferably 1.05 g/cm 3 or more. Since a higher density is preferable, there is no need to limit the upper limit.
　例えば、このような固体バイオ燃料を１００ｔ／年規模の石炭コークス炉へ１００％石炭コークス代替燃料として使用した場合のＣＯ２削減量について、表のようにまとめることができる。 For example, the amount of CO 2 reduction when such solid biofuel is used as a 100% coal-coke alternative fuel in a 100 t/year scale coal-coke oven can be summarized as shown in the table.
　表１を参照する。表１はＣＯ２削減見積もりの前提条件を表す。スギをバイオマス原料とした場合と石炭コークスおよび天然ガスの燃焼の諸元を表１の様な数値とした。次にバイオマス原料を第一工程（「前処理」と記した。）および第二工程（「固形化」と記した。）を経て固体バイオ燃料とし、代替率１００％とした時の、代替によるＣＯ２削減量と固体バイオ燃料作成のために使用するＣＯ２排出量から総ＣＯ２削減量を求めたものである。 See Table 1. Table 1 presents the assumptions for CO2 reduction estimates. Table 1 shows the numerical values for the case of using cedar as a biomass raw material and the combustion of coal-coke and natural gas. Next, the biomass raw material is converted into a solid biofuel through the first step (written as “pretreatment”) and the second step (written as “solidification”), and when the substitution rate is 100%, The total CO2 reduction is obtained from the CO2 reduction and the CO2 emissions used for solid biofuel production.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　このように、揮発分放出により原料よりも必要量は増加するが、燃料比の大幅な向上に加え、天然ガスを活用した場合、ＣＯ２削減に貢献することができる。さらに天然ガスを再生エネルギーに切り替えることでさらなるＣＯ２削減へ貢献することができる。 In this way, although the required amount is higher than the raw material due to the release of volatile matter, in addition to the significant improvement in the fuel ratio, if natural gas is used, it can contribute to the reduction of CO2 . Furthermore, switching from natural gas to renewable energy can contribute to further CO2 reduction.
　半炭化前状態の原料として、スギを１ｍｍ以下にチップ化したものを用いた。半炭化前状態の原料としての性状は、揮発分８１．６％、固定炭素量１８．０％、灰分０．４０％であった。したがって、バイオマス原料の燃料比は０．２２程度であった。 As a raw material before semi-carbonization, cedar chips of 1 mm or less were used. The raw material before semi-carbonization had a volatile content of 81.6%, a fixed carbon content of 18.0%, and an ash content of 0.40%. Therefore, the fuel ratio of the biomass feedstock was about 0.22.
　半炭化前状態の原料を１０℃／ｍｉｎの昇温レートで３００℃まで昇温させ、３００℃到達後５分間保持した。その後自然冷却で常温まで冷却し、半炭化済原料を得た。 The raw material before semi-carbonization was heated to 300°C at a heating rate of 10°C/min, and held for 5 minutes after reaching 300°C. After that, it was naturally cooled to room temperature to obtain a semi-carbonized raw material.
　この半炭化済原料を熱天秤により不活性雰囲気下で１０℃／ｍｉｎで常温から設定温度１０７℃まで昇温し、設定温度到達後に３０ｍｉｎ保持、保持後に１０℃／ｍｉｎで設定温度９００℃まで昇温させ、９００℃到達後に１０ｍｉｎ保持した。その重量減少から、半炭化前状態の原料中の揮発分を約３０ポイント低下させたことが分かった。結果、半炭化済原料の燃料比は、０．３５程度なり、バイオマス原料の燃料比（０．２２）から０．１３増加した。 This semi-carbonized raw material is heated from room temperature to a set temperature of 107° C. at a rate of 10° C./min under an inert atmosphere using a thermobalance, held for 30 minutes after reaching the set temperature, and then raised to a set temperature of 900° C. at a rate of 10° C./min. It was heated and held for 10 minutes after reaching 900°C. The weight loss indicated a reduction of about 30 points in volatiles in the pre-charred feedstock. As a result, the fuel ratio of the semi-carbonized raw material was about 0.35, which was 0.13 higher than the fuel ratio of the biomass raw material (0.22).
　次に第二段工程を以下の様に行った。第一段工程により得られた半炭化済原料をφ４ｍｍの円筒形成型容器に充填した。成型容器は、圧力をかけながら加熱できる固体バイオ燃料製造装置にセットし、初期圧縮荷重として約４４ＭＰａの圧力を成型容器内の半炭化済原料に印加した。その後設定温度である２８０℃まで加熱した。昇温過程では、バックプレッシャーが掛かり、２８０℃の目標温度到達時には、初期圧縮荷重を超える圧縮荷重が成型容器内の試料にかかった。 Next, the second stage process was performed as follows. The semi-carbonized raw material obtained in the first step was filled in a φ4 mm cylindrical container. The molding vessel was set in a solid biofuel manufacturing apparatus capable of heating under pressure, and a pressure of about 44 MPa was applied to the semi-carbonized raw material in the molding vessel as an initial compressive load. After that, it was heated to a set temperature of 280°C. During the temperature rising process, back pressure was applied, and when the target temperature of 280°C was reached, a compressive load exceeding the initial compressive load was applied to the sample in the molding container.
　成型温度２８０℃の状態でその最大到達圧力を維持ながら１分１５秒維持し、さらに自然冷却過程で少なくとも１００℃以下になるまでその到達最大圧力を維持させ、５０℃以下になるのを確認し固体バイオ燃料を取り出した。 Maintain the maximum ultimate pressure at a molding temperature of 280°C for 1 minute and 15 seconds, then maintain the maximum ultimate pressure until the temperature drops to at least 100°C or less in the natural cooling process, and confirm that the maximum pressure reaches 50°C or less. Solid biofuel was taken out.
　この固体バイオ燃料を、熱天秤により不活性雰囲気下で１０℃／ｍｉｎで常温から設定温度１０７℃まで昇温し、設定温度到達後に３０ｍｉｎ保持、保持後に１０℃／ｍｉｎで設定温度９００℃まで昇温させ、９００℃到達後に１０ｍｉｎ保持した。その重量減少から燃料比を算出すると約１．１５の実測値が得られた。 This solid biofuel is heated from room temperature to a set temperature of 107°C at a rate of 10°C/min in an inert atmosphere using a thermobalance, held for 30 minutes after reaching the set temperature, and then raised to a set temperature of 900°C at a rate of 10°C/min. It was heated and held for 10 minutes after reaching 900°C. When the fuel ratio was calculated from the weight reduction, a measured value of about 1.15 was obtained.
　この結果を図６に示す。図６を参照して、横軸はサンプルの種類であり縦軸は燃料比（無単位）である。半炭化前状態の原料自体の燃料比０．２２から半炭化済原料になった際には、０．３５となり、固体バイオ燃料になって燃料比が１．１５に向上した。 The results are shown in Figure 6. Referring to FIG. 6, the horizontal axis is the sample type and the vertical axis is the fuel ratio (unitless). The fuel ratio of the raw material itself before semi-carbonization, which was 0.22, became 0.35 when the raw material was semi-carbonized, and the fuel ratio improved to 1.15 when it became a solid biofuel.
　図７には、第一段工程の半炭化工程を経ずにバイオマス原料を直接１９０℃で固形化した場合のサンプル（比較例）の燃料比の変移を示す。なお、本発明は「実施例」とした。図７を参照して、横軸はサンプルの種類であり縦軸は燃料比である。第一段工程を経ない場合は半炭化前状態の原料を１９０℃で直接加圧成型した。成型時の初期圧力は約４４ＭＰａで本発明に係る固体バイオ燃料の場合と同じとした。圧力の調整方法も同じである。すなわち、バックプレッシャーが実施例の場合と同様に生じる。 Fig. 7 shows changes in the fuel ratio of a sample (comparative example) when the biomass raw material is directly solidified at 190°C without going through the semi-carbonization process of the first step. In addition, this invention was made into the "Example." Referring to FIG. 7, the horizontal axis is the sample type and the vertical axis is the fuel ratio. When the first step was not performed, the pre-semi-carbonized raw material was directly pressure-molded at 190°C. The initial pressure during molding was about 44 MPa, which was the same as for the solid biofuel according to the present invention. The pressure adjustment method is also the same. That is, back pressure occurs as in the case of the embodiment.
　その結果、比較例の燃料比は０．２（バイオマス原料）から０．３６（処理後）程度に向上した。隣には図６で示した半炭化済原料から第二段工程によって得られた固体バイオ燃料の燃料比の変化を再度示した。これらの違いは、加熱加圧の対象が半炭化前状態の原料（比較例）と半炭化済原料（実施例）という点と、成型温度が１９０℃（比較例）と２８０℃（実施例）の違いであると言える。 As a result, the fuel ratio of the comparative example improved from 0.2 (biomass raw material) to about 0.36 (after treatment). Next, the change in the fuel ratio of the solid biofuel obtained from the semi-carbonized raw material shown in FIG. 6 by the second step process is shown again. The difference between these is that the object of heating and pressurization is the raw material before semi-carbonization (comparative example) and the semi-carbonized raw material (example), and the molding temperature is 190 ° C. (comparative example) and 280 ° C. (example). It can be said that the difference is
　半炭化前状態の原料は、加圧しながら熱処理を行うと、ガス化による影響で２８０℃の温度では、圧密成型ができない。しかし、半炭化済原料は、ガス化する量が少なく２８０℃の温度でも圧密成型が可能であった。 If the raw material before semi-carbonization is heat-treated while being pressurized, it cannot be compacted at a temperature of 280°C due to gasification. However, the semi-carbonized raw material had a small amount of gasification, and compaction molding was possible even at a temperature of 280°C.
　したがって、第一段工程の半炭化処理により適度の揮発分（ＶＭ）を放出させることで試料のガス量を減少させ、第二段工程における圧密成型時に半炭化処理を行いながら圧密固形化できたと考えられる。 Therefore, it is possible to reduce the amount of gas in the sample by releasing an appropriate amount of volatile matter (VM) in the semi-carbonization process in the first stage process, and to compact and solidify while performing the semi-carbonization process during compaction molding in the second stage process. Conceivable.
　図８には、密度について測定した結果を示す。図８を参照して、横軸はサンプルの種類であり、縦軸は密度（ｇ／ｃｍ３）である。サンプルとしては、半炭化前状態の原料を常温で４４ＭＰａで加圧し、非加圧で加熱し１９０℃で成型したもの（横軸左端）、半炭化前状態の原料を直接４４ＭＰａ、１９０℃の条件で加圧しながら加熱したもの（横軸中央）、半炭化済原料を直接４４ＭＰａ、２８０℃の条件で加圧しながら加熱したもの（横軸右端）である。中央と右端のサンプルはそれぞれ図７の比較例および実施例に対応する。 FIG. 8 shows the results of density measurements. With reference to FIG. 8, the horizontal axis is the sample type, and the vertical axis is the density (g/cm 3 ). As samples, the pre-semi-carbonized raw material was pressurized at room temperature at 44 MPa, heated without pressure, and molded at 190 ° C. (left end of the horizontal axis), and the pre-semi-carbonized raw material was directly subjected to 44 MPa and 190 ° C. (the center of the horizontal axis), and the semi-carbonized raw material was directly heated under the conditions of 44 MPa and 280° C. (right end of the horizontal axis). The middle and rightmost samples correspond to the comparative example and example in FIG. 7, respectively.
　図８を参照して、半炭化前状態の原料を加圧して成型した後に、加熱すると密度は１．０ｇ／ｃｍ３を下回っていた（横軸左端）。これは、非加圧の状態で加熱、成型したためであると考えられた。 Referring to FIG. 8, when the pre-semi-carbonized raw material was pressurized and molded and then heated, the density fell below 1.0 g/cm 3 (horizontal axis left end). It was considered that this was due to heating and molding in a non-pressurized state.
　一方、加圧しながら加熱、成型すると、密度は向上した（横軸中央と横軸右端）。 On the other hand, when heating and molding while pressurizing, the density improved (the center of the horizontal axis and the right end of the horizontal axis).
　密度という観点だけで見ると、半炭化前状態の原料を加熱加圧した方（横軸中央）が半炭化済原料を加熱加圧した方（横軸右端）より高くなった。しかし、揮発分が多く存在するために燃料比が高くならない点は図７で示した通りである。 From the viewpoint of density alone, the pre-semi-carbonized raw material heated and pressed (center of the horizontal axis) was higher than the half-carbonized raw material heated and pressed (right end of the horizontal axis). However, as shown in FIG. 7, the fuel ratio does not increase due to the presence of a large amount of volatile matter.
　本発明に係る固体バイオ燃料（実施例：図８横軸右端）では、第一段工程で半炭化処理が行われ、ある程度の揮発分が抜けた半炭化済原料を加圧加熱するので、揮発分の割合としてはバイオマス原料を直接加圧加熱した場合より低下したものの、密度は１．０ｇ／ｃｍ３以上を維持することができた。 In the solid biofuel according to the present invention (example: right end of horizontal axis in FIG. 8), semi-carbonization treatment is performed in the first step, and the semi-carbonized raw material from which a certain amount of volatile matter has been removed is pressurized and heated, so volatilization The density was maintained at 1.0 g/cm 3 or more, although the ratio of minutes was lower than when the biomass raw material was directly pressurized and heated.
　本発明に係る固体バイオ燃料は燃料比が０．４を超え、密度が１．０ｇ／ｃｍ３以上のものを得ることができる。したがって、石炭コークスの代替品若しくは併用品として好適に利用できＣＯ２削減に寄与することができる。

  The solid biofuel according to the present invention can have a fuel ratio of more than 0.4 and a density of 1.0 g/cm 3 or more. Therefore, it can be suitably used as a substitute for or used in combination with coal coke, and can contribute to CO2 reduction.

Claims (4)

  1. 　光合成に起因するバイオマスをチップ化した原料だけを用い、前記原料を少なくとも１個以上押し固めた固体バイオ燃料であって、燃料比が０．４以上２．０以下であり、密度が１．０ｇ／ｃｍ３以上である固体バイオ燃料。 A solid biofuel obtained by compacting at least one or more chips of biomass resulting from photosynthesis, and having a fuel ratio of 0.4 or more and 2.0 or less and a density of 1.0 g. /cm 3 or more solid biofuel.
  2. 　前記バイオマスがスギである請求項１に記載された固体バイオ燃料。 The solid biofuel according to claim 1, wherein the biomass is cedar.
  3. 　光合成に起因するバイオマスをチップ化した原料を、半炭化処理し、前記原料中の水分・揮発分の一部を放出させる半炭化済原料を得る第一段工程と、
    　前記半炭化済原料を常に最大圧力を更新しながら加熱加圧し加熱加圧品を得る加熱加圧工程と、
    　前記加熱加圧品に、常に最大圧力を更新しながら所定時間成型し、成型品を得る成型工程と、
    　冷却開始時の前記成型品にかかる圧力を維持した状態で、前記成型品を冷却する冷却工程によって圧密成型物を得る第二段工程を有する固体バイオ燃料の製造方法。     A first stage step of obtaining a semi-carbonized raw material by semi-carbonizing the raw material obtained by chipping the biomass resulting from photosynthesis and releasing a part of the moisture and volatile matter in the raw material;
    A heating and pressurizing step of obtaining a heated and pressurized product by heating and pressurizing the semi-carbonized raw material while constantly renewing the maximum pressure;
    A molding step of molding the heated and pressurized product for a predetermined time while constantly renewing the maximum pressure to obtain a molded product;
    A method for producing a solid biofuel, comprising a second step of obtaining a compacted product by a cooling step of cooling the molded product while maintaining the pressure applied to the molded product at the start of cooling.
  4. 　前記第二段工程の最大成型温度は１９０℃より高い請求項３に記載された固体バイオ燃料の製造方法。

          4. The method for producing solid biofuel according to claim 3, wherein the maximum molding temperature in the second step is higher than 190[deg.]C.
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