High-temperature and high-pressure treatment apparatus

Abstract

To provide an economical and reliable high-temperature high-pressure treatment device that can suppress facility costs without a risk of causing leakage of slurry from a sliding part (seal part) when a screw mechanism is used.SOLUTION: A high-temperature high-pressure treatment device includes: a slurry preparation part 10 for preparing biomass slurry containing biomass, a thickener, and water at predetermined proportions; a heating part 30 for heating the prepared biomass slurry so that it is brought into a predetermined subcritical state; a reaction part 40 for causing a hydrothermal reaction by biomass and water by supplying the heated biomass slurry continuously and causing the biomass slurry to pass through the reaction part taking a predetermined time; a cooling part 50 for cooling the slurry after the hydrothermal reaction; and a pressure adjustment mechanism 60 for adjusting the pressure in the system.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a biomass processing apparatus, and more particularly to a high-temperature and high-pressure processing apparatus that subjects biomass slurry to a subcritical state and treats it by subjecting biomass and water to a hydrothermal reaction.

Background Art

[0002] In recent years, as a method for effectively utilizing biomass, a method of dispersing biomass in water to form a slurry and treating this biomass slurry under high temperature and high pressure (hydrothermal reaction) to recover valuable substances such as saccharides is known.

[0003] By the way, when continuously supplying biomass slurry to a high-temperature and high-pressure processing apparatus (hereinafter also simply referred to as an apparatus), sedimentation and separation of solids in the biomass slurry occur in the apparatus, resulting in blockage by solids in the apparatus and variations in the components and composition of the recovered substances due to non-uniform solid concentration.

[0004] Therefore, as a reactor capable of overcoming such problems caused by sedimentation of solids, Patent Document 1 proposes a continuous reactor for cellulose-based biomass slurry in which a screw mechanism is installed in the apparatus to suppress and prevent sedimentation of solids.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the case of the continuous reactor for slurry of Patent Document 1, there is a problem that the equipment cost increases because the configuration is complicated with a screw mechanism arranged in an apparatus operated at high temperature and high pressure.

[0007] In addition, the sliding part of the screw mechanism is provided with a seal mechanism for preventing liquid leakage. However, since the screw mechanism is used under high temperature and high pressure and the liquid to be treated is a slurry containing solid components, liquid leakage at the sliding part (sealing part) is a concern.

[0008] Furthermore, in order to suppress the sedimentation of solid components and satisfy the plug flow in which solid components do not short-circuit, it is necessary to optimize the operating conditions such as the rotation speed of the screw mechanism. However, it is not always easy to find the optimal operating conditions and stably maintain those conditions to continue the operation.

[0009] The present invention solves the above problems, does not require a screw mechanism, can suppress equipment costs, and there is no risk of causing slurry leakage from the sliding part (sealing part) as is a concern when using a screw mechanism, and aims to provide a high temperature and high pressure treatment device with excellent economic efficiency and reliability.

Means for Solving the Problems

[0010] To solve the above problems, the high temperature and high pressure treatment device of the present invention is A high temperature and high pressure treatment device used for continuously performing high temperature and high pressure treatment on biomass slurry under a subcritical state, A slurry preparation unit that prepares a biomass slurry containing biomass, a thickener, and water in a predetermined ratio, A heating unit that heats the biomass slurry prepared by the slurry preparation unit to a predetermined subcritical state, A reaction unit configured to continuously supply the biomass slurry heated by the heating unit and pass it through for a predetermined time to cause a hydrothermal reaction between the biomass and water in the biomass slurry, A cooling unit that cools the slurry after performing the hydrothermal reaction in the reaction unit, A pressure adjustment mechanism that adjusts the pressure in the system including the heating unit, the reaction unit, and the cooling unit It is characterized by comprising.

[0011] In the high-temperature and high-pressure treatment apparatus of the present invention, the regions of the heating section, the reaction section, and the cooling section through which the biomass slurry passes are preferably configured as tubular regions that do not include a drive mechanism for stirring or transporting the biomass slurry.

[0012] Also, in the high-temperature and high-pressure treatment apparatus of the present invention, it is preferable that the reaction section is provided with heating means and is configured to be able to maintain the passing biomass slurry in a predetermined subcritical state.

[0013] Also, in the high-temperature and high-pressure treatment apparatus of the present invention, it is preferable that a plant-based thickener is used as the thickener.

[0014] Also, it is preferable that a carboxymethyl cellulose-based thickener or cellulose nanofibers are used as the thickener.

[0015] Also, it is preferable to use plant-based biomass as the biomass.

[0016] Also, it is preferable that the content rate of the thickener in the biomass slurry prepared in the slurry preparation section is configured to be 0.1% by weight or more and less than 3.0% by weight.

[0017] Also, it is preferable that the content rate of the solid content in the biomass slurry prepared in the slurry preparation section is configured to be 25% by weight or less.

Advantages of the Invention

[0018] The high-temperature, high-pressure treatment apparatus of the present invention is configured to include a slurry preparation section that prepares a biomass slurry containing biomass, a thickener, and water in a predetermined ratio; a heating section that heats the prepared biomass slurry to a predetermined subcritical state; a reaction section that continuously supplies the heated biomass slurry and passes it through for a predetermined time to cause a hydrothermal reaction between the biomass and water; a cooling section that cools the slurry after the hydrothermal reaction; and a pressure adjustment mechanism that adjusts the pressure within the system.By adding a thickener to the biomass slurry, it is possible to suppress settling and separation of the solid content (biomass).This makes it possible to supply a biomass slurry in a dispersed state to the reaction section and efficiently cause a hydrothermal reaction between the biomass and water without the need for a screw mechanism like the continuous slurry reactor of Patent Document 1.

[0019] There are no particular restrictions on the type of biomass that can be treated by the high-temperature, high-pressure treatment device of the present invention, and the high-temperature, high-pressure treatment device of the present invention can be used to treat various types of biomass slurries.

[0020] Furthermore, when the areas in the heating section, reaction section, and cooling section through which the biomass slurry passes are configured as tubular areas that do not have a driving mechanism for stirring or transporting the biomass slurry, it becomes possible to reliably transport the biomass slurry from the heating section, through the reaction section, to the cooling section without using, for example, a screw mechanism or kneader.

[0021] As a result, a high-temperature, high-pressure treatment apparatus capable of stable operation without the need for a screw mechanism can be realized. Furthermore, since a screw mechanism is not required, it is possible to reduce equipment costs, and it is possible to realize a highly reliable high-temperature, high-pressure treatment apparatus without the risk of problems such as leakage of slurry from sliding parts, which are a concern in apparatuses using a screw mechanism.

[0022] Furthermore, by configuring the reaction section to be equipped with a heating means and to maintain the biomass slurry passing through the reaction section in a predetermined subcritical state, even if the time required for the biomass slurry to pass through the reaction section is longer, it becomes possible to maintain the biomass slurry in a predetermined subcritical state that is desirable for causing a hydrothermal reaction, and the intended hydrothermal reaction can be caused.

[0023] Furthermore, in the high-temperature, high-pressure treatment apparatus of the present invention, by using a plant-based thickener as the thickener, it is possible to reliably suppress the settling and separation of solids, thereby enabling the hydrothermal reaction to be carried out efficiently, and it is also possible to prevent the reaction product obtained by the hydrothermal reaction from containing harmful substances, thereby avoiding restrictions on the use of the reaction product.

[0024] Examples of plant-based thickeners include xanthan gum, which is made by fermenting starch, carrageenan, which is extracted from seaweed, and guar gum, which is extracted from the seeds of legumes.

[0025] Furthermore, when a carboxymethyl cellulose-based thickener or cellulose nanofiber is used as the thickener, it is possible to reliably suppress the settling and separation of solids, thereby enabling the hydrothermal reaction to be carried out efficiently, and it is also possible to prevent harmful substances from being contained in the reaction product obtained by the hydrothermal reaction, thereby avoiding restrictions on the use of the reaction product.

[0026] Furthermore, when plant biomass is used as the biomass, valuable substances such as sugars can be recovered by subjecting the biomass and water in the biomass slurry to a sufficient hydrothermal reaction in the reaction section and then fermenting the treated liquid using microorganisms. When the objective is to recover valuable substances such as sugars from plant biomass as a raw material, the use of a non-toxic thickener such as a carboxymethylcellulose-based thickener, cellulose nanofiber, or other plant-based thickener that can also be used as a food additive makes it possible to recover valuable substances such as sugars that do not contain harmful substances.

[0027] Also, when the content rate of the thickener in the biomass slurry prepared in the slurry preparation section is configured to be 0.1% by weight or more and less than 3.0% by weight, it becomes possible to suppress and prevent the sedimentation of the solid content contained in the biomass slurry, and even without a stirring mechanism such as a screw mechanism, in the reaction section, it becomes possible to efficiently perform a hydrothermal reaction between the biomass and water.

[0028] Note that when the content rate of the thickener in the biomass slurry is less than 0.1% by weight, the thickening effect becomes insufficient, and when it exceeds 3.0% by weight, the viscosity becomes too high, which is not preferable.

[0029] Also, when there is a usage standard for the thickener in the product to be manufactured by performing high-temperature and high-pressure treatment, it is preferable to adjust the addition amount of the thickener according to the usage standard. For example, the usage standard of carboxymethyl cellulose in food is 2% or less.

[0030] Also, even when the thickener is in a gelled state without being completely dissolved in the biomass slurry, it can be used.

[0031] Also, when the content rate of the solid content in the biomass slurry prepared in the slurry preparation section is configured to be 25% by weight or less, it becomes possible to maintain the biomass slurry in a flowable state and ensure handleability.

[0032] Note that the lower the content rate of the solid content in the biomass slurry, the better the fluidity, but when processing the same amount of biomass, the handling amount of the biomass slurry increases. Therefore, usually, within the range where the necessary fluidity can be ensured, it is desirable to increase the content rate of the solid content in the biomass slurry, for example, to 10% by weight or more.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

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Figure 4

Embodiments for Carrying Out the Invention

[0034] Hereinafter, embodiments of the present invention will be shown and the features of the present invention will be described in more detail.

[0035] [First Embodiment] FIG. 1 is a diagram showing the configuration of a high-temperature and high-pressure treatment apparatus according to a first embodiment of the present invention.

[0036] The high-temperature and high-pressure treatment apparatus 100A according to this first embodiment is a high-temperature and high-pressure treatment apparatus used for continuously subjecting a biomass slurry in which biomass is dispersed in water to high-temperature and high-pressure treatment (hydrothermal reaction) under a subcritical state.

[0037] By the way, biomass is classified into, for example, unused biomass, waste-based biomass, and resource crops.

[0038] Examples of unused biomass include rice straw, wheat straw, rice husks, bamboo, and forest residues. Examples of waste-based biomass include livestock manure, food waste, waste paper, black liquor (pulp mill waste liquid), sewage sludge, construction-generated wood, and residues from sawmills. Furthermore, examples of resource crops include sugar resources (such as sugarcane), starch resources (such as corn), oil resources (such as rapeseed), willow, poplar, and switchgrass.

[0039] In addition, rice straw, wheat straw, rice husks, bamboo, forest residues such as branches and leaves generated during logging and lumbering of trees, bark, sawdust, etc. generated from sawmills, etc. may be classified as plant-based biomass in a broad sense.

[0040] Although the high-temperature and high-pressure treatment apparatus of the present invention can be applied to treat any of the above-mentioned various biomasses, in this embodiment, as an example, the case where unused biomass and rice straw, which is the above-mentioned plant-based biomass, is used will be described.

[0041] As shown in FIG. 1, the high-temperature and high-pressure treatment apparatus 100A according to the first embodiment includes a slurry preparation unit 10 for preparing a biomass slurry containing plant-based biomass (rice straw) (hereinafter also simply referred to as "biomass"), a thickener, and water in a predetermined ratio, and a slurry supply tank (slurry supply tank) 20 that receives the biomass slurry prepared by the slurry preparation unit 10.

[0042] The high-temperature and high-pressure treatment apparatus 100A also includes a heating unit 30 that heats the biomass slurry supplied from the slurry supply tank 20 to a predetermined subcritical state.

[0043] It is desirable that the heating unit 30 is configured to be able to heat the biomass slurry in the range of 150 to 250°C and a pressure of 1.0 to 5.0 MPa.

[0044] The high-temperature and high-pressure treatment apparatus 100A also includes a reaction unit 40 that continuously supplies the biomass slurry heated by the heating unit 30 and allows it to pass through over a predetermined time to cause a hydrothermal reaction between the biomass and water.

[0045] It is desirable that the reaction unit 40 is configured such that the biomass slurry continuously supplied through the heating unit 30 passes through over a period of 10 to 30 minutes, that is, a reaction time of 10 to 30 minutes is ensured.

[0046] Further, the high-temperature and high-pressure treatment apparatus 100A includes a cooling unit 50 that cools the slurry after the hydrothermal reaction is performed in the reaction unit 40 to a predetermined temperature.

[0047] Furthermore, the high-temperature and high-pressure treatment apparatus 100A includes a pressure adjustment mechanism 60 for adjusting the pressure inside the system (inside the system including the heating unit 30, the reaction unit 40, and the cooling unit 50) on the downstream side of the cooling unit 50.

[0048] In this embodiment, a discharge pump 60a for discharging the cooled biomass slurry after the hydrothermal reaction into a treatment liquid tank functions as the pressure adjustment mechanism 60 for adjusting the pressure inside the system. That is, by controlling the flow rate when discharging the biomass slurry after the hydrothermal reaction by the discharge pump 60a, the pressure inside the system can be maintained at a pressure higher than the saturation pressure at the temperature at which the biomass slurry reaches the subcritical state.

[0049] Since the high-temperature and high-pressure treatment apparatus 100A according to this embodiment includes the pressure adjustment mechanism 60 as described above, it is possible to prevent a situation in which the pressure inside the system decreases during the operation of the apparatus and water flashes, causing the temperature of the biomass slurry to decrease and making it impossible to maintain the subcritical state, and perform stable high-temperature and high-pressure treatment.

[0050] Further, the high-temperature and high-pressure treatment apparatus 100A according to this embodiment includes a treatment liquid tank 70 for storing the biomass slurry after the hydrothermal reaction that is cooled by the cooling unit 50 and discharged through the pressure adjustment mechanism 60.

[0051] Although not particularly shown, the high-temperature and high-pressure treatment apparatus 100A according to this embodiment includes a separation device (such as a filtration device or a filter press) for separating solids contained in the biomass slurry after the hydrothermal reaction, an enzyme treatment apparatus for enzyme-treating the treatment liquid after the solids are separated, and the like.

[0052] Next, the high-temperature, high-pressure processing apparatus 100A according to this embodiment will be described in more detail, including elements other than the main components described above.

[0053] The slurry blending section 10, which blends biomass slurry, is equipped with a powder mixer 10a that mixes biomass and thickener in a predetermined ratio, and a slurry blending tank 10b into which the mixed powder of biomass and thickener mixed in the powder mixer 10a and water are poured. The slurry blending tank 10b is equipped with an agitator 10c for stirring the contents.

[0054] In this embodiment, as described above, plant biomass is used as the biomass, and a carboxymethyl cellulose-based thickener (carboxymethyl cellulose sodium (CMC-Na)) is used as the thickener.

[0055] In this embodiment, in the slurry blending section 10, a mixed powder of biomass and thickener mixed in a powder mixer 10a and water are charged into a slurry blending tank 10b, and mixed by an agitator 10c to prepare a biomass slurry.

[0056] In this embodiment, the mixed powder of biomass and thickener and water are mixed in a batch operation, but the mixed powder of biomass and thickener and water can also be mixed continuously.

[0057] In this embodiment, the solid content (biomass) in the biomass slurry was set to 15% by weight. In the present invention, the solid content (biomass) in the biomass slurry is preferably 25% by weight or less.

[0058] The lower the solid content in the biomass slurry, the higher the fluidity. However, when processing the same amount of biomass, the handling amount of the biomass slurry increases, leading to a decrease in productivity. Therefore, usually, within the range where the necessary fluidity can be ensured, it is desirable to increase the solid content in the biomass slurry. Usually, it is desirable to set the solid content in the biomass slurry to 10% by weight or more.

[0059] In the present invention, the preferable range of the thickener content in the biomass slurry is in the range of 0.1% by weight or more and less than 3.0% by weight. In this embodiment, it is set to 1.5% by weight.

[0060] By setting the above conditions, the biomass slurry containing the thickener prepared in the slurry preparation unit 10 becomes a slurry with good handleability and fluidity that can suppress the sedimentation and separation of solids (biomass) without using a screw mechanism.

[0061] The biomass slurry prepared in the slurry preparation unit 10 as described above is sent to the slurry supply tank (slurry supply tank) 20 via the preparation slurry pump 15.

[0062] Then, the biomass slurry sent to the slurry supply tank (slurry supply tank) 20 is supplied to the heating unit 30 via the supply pump 25.

[0063] The heating unit 30 includes a tubular portion 30a through which the biomass slurry passes and a jacket 30b disposed around the tubular portion 30a, and is configured such that a heat medium flows through the jacket 30b.

[0064] Note that the tubular portion 30a, which is the region through which the biomass slurry passes in the heating unit 30, is configured as a hollow tubular region that does not include a drive mechanism for stirring or conveying the biomass slurry.

[0065] The biomass slurry continuously supplied to the heating unit 30 at a predetermined speed via the supply pump 25 is indirectly heated by the heat medium flowing through the jacket 30b when passing through the tubular part 30a of the heating unit 30 until it reaches a predetermined subcritical state.

[0066] When operating the high-temperature and high-pressure treatment device 100A in a subcritical state, the pressure inside the device is first increased to a pressure higher than the saturation pressure at the temperature at which the biomass slurry reaches the subcritical state, and then the heating in the heating unit 30 is started to heat the biomass slurry until it reaches the subcritical state.

[0067] For example, when operating by heating the biomass slurry to 150°C, the pressure inside the device is first increased to 1.0 MPa, then the heating in the heating unit 30 is started, and the temperature is raised until the biomass slurry reaches 150°C to perform the operation in a subcritical state. Also, when operating by heating the biomass slurry to 250°C, the pressure inside the device is first increased to 5.0 MPa, then the heating in the heating unit 30 is started, and the temperature is raised until the biomass slurry reaches 250°C to perform the operation in a subcritical state.

[0068] In this embodiment, the biomass slurry is heated in the heating unit 30 from a state with a pressure of 2.0 MPa until it reaches 180°C and is configured to be in a subcritical state.

[0069] Then, the biomass slurry heated in the heating unit 30 as described above and in a subcritical state is continuously sent to the reaction unit 40 at a predetermined speed.

[0070] The reaction unit 40 includes a tubular part 40a through which the biomass slurry passes and a jacket 40b disposed around the tubular part 40a, and is configured such that the heat medium flows through the jacket 40b.

[0071] Note that the tubular portion 40a, which is the region through which the biomass slurry passes in the reaction section 40, is configured as a hollow tubular region without a drive mechanism for stirring or transporting the biomass slurry.

[0072] The biomass slurry passing through the reaction section 40 is kept warm (heated) by the heat medium flowing through the jacket 40b even when passing through the tubular portion 40a of the reaction section 40, and a predetermined temperature and pressure (i.e., a predetermined subcritical state) are maintained. Therefore, in the process of passing through the reaction section 40, the hydrothermal reaction between the biomass and water in the biomass slurry proceeds sufficiently.

[0073] Note that in this embodiment, the biomass slurry is configured to pass through the reaction section 40 in 20 minutes, that is, the reaction time is 20 minutes. By ensuring a reaction time of 20 minutes, the hydrothermal reaction between the biomass and water in the biomass slurry can proceed sufficiently.

[0074] In this way, the biomass slurry that has undergone the hydrothermal reaction (high-temperature and high-pressure treatment) in the reaction section 40 is sent to the cooling section 50.

[0075] The cooling section 50 includes a tubular portion 50a through which the biomass slurry passes and a jacket 50b disposed around the tubular portion 50a, and is configured such that a refrigerant flows through the jacket 50b.

[0076] Note that the tubular portion 50a, which is the region through which the biomass slurry passes in the cooling section 50, is configured as a hollow tubular region without a drive mechanism for stirring or transporting the biomass slurry.

[0077] The biomass slurry after the reaction sent to the cooling section 50 is indirectly cooled by the refrigerant flowing through the jacket 50b when passing through the tubular portion 50a of the cooling section 50 and is cooled to a predetermined temperature.

[0078] The biomass slurry after the hydrothermal reaction cooled by the cooling unit 50 is discharged out of the system through the pressure adjustment mechanism 60 (discharge pump 60a) and stored in the treatment liquid tank 70. As described above, a discharge pump 60a for discharging the biomass slurry after the hydrothermal reaction into the treatment liquid tank is used as the pressure adjustment mechanism 60.

[0079] Then, the biomass slurry after the hydrothermal reaction stored in the treatment liquid tank 70 is sent to a separation device, and solids are separated.

[0080] The treatment liquid from which solids have been separated is sent to an enzyme treatment device and fermented using microorganisms, so that it becomes possible to recover saccharides adjusted to a predetermined number of carbon atoms as valuable substances.

[0081] Next, using the above-described high-temperature and high-pressure treatment device 100A, the conditions and results when rice straw, which is a plant-based biomass, is subjected to high-temperature and high-pressure treatment are summarized and described below. 1) Type of biomass used as the treatment target (raw material) Finely pulverized rice straw, which is a plant-based biomass 2) Thickening agent Sodium carboxymethyl cellulose (CMC-Na) 3) Solids (biomass) content in the prepared biomass slurry 15% by weight 4) Thickening agent content in the prepared biomass slurry 1.5% by weight 5) Time required for the biomass slurry to pass through the reaction section (hydrothermal reaction time) 20 minutes 6) Conditions in the reaction section (subcritical conditions) 180 °C (2.0 MPa)

[0082] By performing high-temperature and high-pressure treatment (hydrothermal reaction) under the above conditions using the above-described high-temperature and high-pressure treatment device 100A and further performing enzyme treatment, it was confirmed that saccharides were obtained at a ratio of about 20% by weight of the biomass raw material before treatment.

[0083] The high-temperature and high-pressure treatment apparatus 100A according to this embodiment is configured as described above. By adding a thickening agent to the biomass slurry, the state in which the solid content (biomass) is dispersed is maintained. Therefore, without using a screw mechanism such as the continuous reactor for slurry in Patent Document 1 described above, the biomass slurry can be supplied to the reaction section in a state where the biomass is dispersed, and the biomass and water can be efficiently subjected to a hydrothermal reaction.

[0084] Also, as described above, the regions through which the biomass slurry passes in the heating section 30, the reaction section 40, and the cooling section 50 are configured as hollow tubular regions (tubular sections 30a, 40a, 50a) that do not include a drive mechanism for stirring or transporting the biomass slurry. Therefore, for example, without using a screw mechanism or a kneader, the biomass slurry in which solids are dispersed can be reliably transported from the heating section 30, through the reaction section 40, and to the cooling section 50.

[0085] As a result, it is possible to reduce the equipment cost compared to an apparatus using a screw mechanism, and there is no risk of causing problems such as leakage of the slurry from the sliding part, which is a concern in the case of an apparatus using a screw mechanism. It is possible to provide a high-temperature and high-pressure treatment apparatus that is excellent in economy and highly reliable.

[0086] In the above embodiment, the heating section 30 and the reaction section 40 are separate bodies, but they may be configured integrally such that a predetermined region on the upstream side functions as the heating section and a predetermined region on the downstream side functions as the reaction section.

[0087] Also, in the above embodiment, the heating section 30 and the reaction section 40 are configured to be able to be indirectly heated using a heat medium, but it is also possible to adopt a configuration using an electric heater as the heating means, a configuration using high-pressure steam as the heat source, or the like.

[0088] In the above-described embodiment, the reaction unit 40 is configured to include a heating means. However, by sufficiently heat-insulating the reaction unit, it is also possible to adopt a configuration without a heating means.

[0089] In the above-described embodiment, plant-based biomass (rice straw) is used as the biomass. However, as the biomass, various biomasses such as waste-based biomass other than plant-based biomass, unused biomass, and energy crops can be used.

[0090] In the above-described embodiment, sodium carboxymethyl cellulose (CMC-Na) is used as the thickener. However, it is also possible to use cellulose nanofibers.

[0091] As other thickeners, it is possible to use plant-based thickeners such as xanthan gum produced by fermenting starch, carrageenan extracted from seaweed, and guar gum extracted from the seeds of leguminous plants.

[0092] When recovering valuable substances such as saccharides using, for example, plant-based biomass, it is desirable to use non-hazardous thickeners such as sodium carboxymethyl cellulose (CMC-Na), cellulose nanofibers, and plant-based thickeners.

[0093] [Second Embodiment] FIG. 2 is a diagram showing the configuration of a high-temperature and high-pressure treatment apparatus 100B according to the second embodiment of the present invention.

[0094] In the above-described first embodiment, the discharge pump 60a for discharging the biomass slurry after the hydrothermal reaction from the cooling unit 50 to the treatment liquid tank 70 is used as the pressure adjustment mechanism 60 for adjusting the pressure in the system. However, in the second embodiment, a pressure adjustment valve 60b is used as the pressure adjustment mechanism 60. Note that various known types of pressure adjustment valves can be used. Other configurations are the same as those in the above-described first embodiment.

[0095] [Third Embodiment] FIG. 3 is a diagram showing the configuration of the high-temperature and high-pressure treatment apparatus 100C according to the third embodiment of the present invention.

[0096] In the above-described first embodiment, after mixing biomass and a thickener in the powder mixer 10a, the mixture is put into the slurry preparation tank 10b and mixed with water separately put into the slurry preparation tank 10b. However, in the third embodiment, water and the thickener are put into the thickener / water tank 80 equipped with the stirrer 80a, and stirred to dissolve the thickener in water in advance.

[0097] Then, the water in which the thickener is dissolved is put into the slurry preparation tank 10b via the pump 85, and biomass is put into the slurry preparation tank 10b and stirred by the stirrer 10c to prepare a biomass slurry. Other configurations are the same as those in the above-described first embodiment.

[0098] [Fourth Embodiment] FIG. 4 is a diagram showing the configuration of the high-temperature and high-pressure treatment apparatus 100D according to the fourth embodiment of the present invention.

[0099] In the above-described third embodiment, the discharge pump 60a for discharging the biomass slurry after the hydrothermal reaction from the cooling unit 50 to the treatment liquid tank 70 is used as the pressure adjustment mechanism 60 for adjusting the pressure in the system. However, in the fourth embodiment, a pressure adjustment valve 60b is used as the pressure adjustment mechanism 60. Note that various known pressure adjustment valves can be used. Other configurations are the same as those in the above-described third embodiment.

[0100] When using the high-temperature and high-pressure treatment apparatuses according to the second, third, and fourth embodiments described above, it is also possible to obtain the same operational effects as when using the high-temperature and high-pressure treatment apparatus according to the first embodiment described above.

[0101] Note that the present invention is not limited to the above-described first to fourth embodiments, and various applications and modifications can be made within the scope of the invention.

[0102] The present invention is not limited to the above embodiments in other respects either, and applications and modifications can be made within the scope of the invention.

[0103] For example, in the case of a distillation apparatus that is operated under conditions such that the overhead vapor of the distillation column becomes high temperature, as a configuration for recovering heat from the cooling water of the condenser used to cool the overhead vapor of the distillation column and using it as a heating source, pure water is used as the cooling water of the condenser, and this cooling water is heat-exchanged with the overhead vapor of the distillation column in the condenser and evaporated, the generated vapor is compressed by a vapor compressor, and the obtained pressurized vapor is blown into the distillation column.

Explanation of Reference Numerals

[0104] 10 Slurry Preparation Section 10a Powder Mixer 10b Slurry Preparation Tank 10c Agitator 15 Prepared Slurry Pump 20 Slurry Supply Tank (Slurry Supply Tank) 25 Supply Pump 30 Heating Section 30a Tubular Section 30b Jacket 40 Reaction Section 40a Tubular Section 40b Jacket 50 Cooling Section 50a Tubular Section 50b Jacket 60 Pressure Adjusting Mechanism 60a Discharge Pump that also Functions as a Pressure Adjusting Mechanism 60b Pressure Adjusting Valve 70 Treatment Liquid Tank 80 Thickener·Water Tank 80a Agitator 85 Pump High-temperature and high-pressure treatment apparatus according to the first embodiment of 100A High-temperature and high-pressure treatment apparatus according to the second embodiment of 100B High-temperature and high-pressure treatment apparatus according to the third embodiment of 100C High-temperature and high-pressure treatment apparatus according to the fourth embodiment of 100D

Claims

1. A high-temperature and high-pressure treatment apparatus used for continuously subjecting a biomass slurry to high-temperature and high-pressure treatment under a subcritical state, comprising: a slurry preparation unit for preparing a biomass slurry containing biomass, a thickener, and water in a predetermined ratio; a heating unit for externally heating the biomass slurry prepared by the slurry preparation unit to a predetermined subcritical state while maintaining the predetermined ratio; a reaction unit disposed downstream of the heating unit via a tubular connection portion, wherein the biomass slurry heated by the heating unit is continuously supplied and configured to pass through the reaction unit over a predetermined time, and the reaction unit is configured to cause a hydrothermal reaction between the biomass and water in the biomass slurry; a cooling unit for cooling the slurry after the hydrothermal reaction is performed in the reaction unit; a pressure adjustment mechanism for adjusting the pressure in the system including the heating unit, the reaction unit, and the cooling unit; and the reaction unit is provided with heating means and is configured to maintain the passing biomass slurry in the predetermined subcritical state. A high-temperature and high-pressure treatment apparatus.

2. The high-temperature and high-pressure treatment apparatus according to claim 1, wherein the regions of the heating unit, the reaction unit, and the cooling unit through which the biomass slurry passes are configured as tubular regions not provided with a drive mechanism for stirring or transporting the biomass slurry.

3. The high-temperature and high-pressure treatment apparatus according to claim 1 or 2, wherein the reaction unit includes a tubular portion configured to allow the biomass slurry to pass horizontally.

4. The high-temperature and high-pressure treatment apparatus according to any one of claims 1 to 3, wherein a plant-based thickener is used as the thickener.

5. The high-temperature and high-pressure treatment apparatus according to any one of claims 1 to 3, wherein a carboxymethyl cellulose-based thickener or cellulose nanofiber is used as the thickener.

6. The high-temperature and high-pressure treatment apparatus according to any one of claims 1 to 5, wherein the biomass is plant-based biomass.

7. The high-temperature and high-pressure treatment apparatus according to any one of claims 1 to 6, wherein the content of the thickener in the biomass slurry prepared by the slurry preparation unit is configured to be 0.1% by weight or more and less than 3.0% by weight.

8. The high-temperature and high-pressure treatment apparatus according to any one of claims 1 to 7, characterized in that the solid content in the biomass slurry prepared in the slurry preparation section is configured to be 25% by weight or less.

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