Hydrogen production system, biomass power generation system, and biomass hydrogen supply system

Abstract

To provide a hydrogen production system that can perform aqueous reaction to superheated steam by utilizing high-temperature gas exhausted from a carbonization furnace.SOLUTION: A hydrogen production system 1 that hydrolyzes biomass into pellets by using a continuous-type subcritical water comprises: a carbonization furnace 3 which incompletely burns and carbonizes pellets; a carbonization rate measuring device 31 which measures a ratio of carbide; a superheated steam generator 4 which generates superheated steam; a thermal decomposition furnace 5 which generates thermally decomposed gas; a water gas recovery device 6; and a control device 90, where the carbonization furnace 3 has: an input port 301a into which pellets are input; a housing part 301 which houses the input carbide; an exhaust port 301b which exhausts carbide created by carbonizing pellets; and a carbonization degree evaluation part 313 which evaluates a carbonization degree of the created carbide, where a control device 90 controls an atmospheric temperature inside the housing part 301 such that a ratio of the carbide measured by the carbonization rate measuring device 31 and a carbonization degree evaluated by the carbonization degree evaluation part 313 become constant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen production system, a biomass power generation system, and a biomass hydrogen supply system, and in particular to a hydrogen production system, a biomass power generation system, and a biomass hydrogen supply system that utilizes biomass (organic waste), which is a renewable energy source, and carbonizes the residue obtained by continuous subcritical treatment using desalted and dehydrated pelletized raw material, and then reacts with water using biomass such as waste materials, with automatic control of the entire system. [Background technology]

[0002] As disclosed in Patent Documents 1 and 2, a biomass power generation system is known in which biomass is pyrolyzed and gasified, and the resulting water gas is used to efficiently generate power in a gas engine or the like.

[0003] Pyrolysis and gasification of wood-based materials (biomass) containing a large amount of lignin has great potential as a new source of energy resources, and in recent years, attempts have been made to make effective use of it. To pyrolyze and gasify wood-based materials, the raw material wood biomass is decomposed into gases (CO, H2, CH4, CO2, H2O), charcoal, and hydrocarbons at temperatures between 600 and 900°C under low-oxygen conditions, and the pyrolysis products are combusted under limited oxygen or air conditions, while the charcoal is heated at high temperatures to gasify it, producing water gas.

[0004] Patent Document 3 discloses a carbonization furnace including a carbonized material discharge section that discharges carbonized material, an air supply section that supplies air for combustion, a temperature sensor that detects the temperature of the carbonized material, and a control section that controls the amount of carbonized material discharged by the carbonized material discharge section according to the temperature detected by the temperature sensor. The control section receives signals from each section included in the carbonization furnace and transmits control signals to each section to control each section, thereby automatically executing each process in the carbonization furnace. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-165019 A [Patent Document 2] Patent No. 6170579 [Patent Document 3] JP 2016-121253 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the techniques disclosed in the above Patent Documents 1 to 3 leave room for improvement in terms of keeping the exhaust gas discharged from the carbonization furnace to be used as a heat source at a certain level or higher.

[0007] Therefore, an object of the present invention is to provide a hydrogen production system, a biomass power generation system, and a biomass hydrogen supply system that can utilize the high-temperature gas discharged from a carbonization furnace to cause an aqueous reaction of superheated steam. [Means for solving the problem]

[0008] In response to the above-mentioned problems, the present invention provides a hydrogen production system that processes biomass into pellets by hydrolysis using continuous subcritical water, the hydrogen production system including a carbonization furnace that incompletely combusts the pellets to carbonize them, a carbonization rate measuring device that measures the ratio of the incompletely combusted carbonized material to the carbonized material obtained by carbonization in the carbonization furnace, a superheated steam generator that heats water vapor to generate superheated steam, and a heat separation device that heats the superheated steam supplied from the superheated steam generator and the carbonized material obtained by carbonization in the carbonization furnace with combustion exhaust gas generated in the carbonization furnace to generate superheated steam. The carbonization furnace includes a pyrolysis furnace that generates decomposition gas, a water gas recovery device that cleans the pyrolysis gas generated in the pyrolysis furnace to recover water gas, and a control device that controls the operation of the carbonization furnace, the superheated steam generation device, the pyrolysis furnace, and the water gas recovery device, wherein the carbonization furnace has an inlet through which the pellets are fed, a storage section that stores the carbonized material fed from the inlet, an outlet through which the carbonized material generated by carbonizing the pellets in the storage section is discharged, and a carbonization degree evaluation section that evaluates the carbonization degree of the generated carbonized material, The control device is characterized in that it controls the atmospheric temperature within the storage unit so that the ratio of carbonized matter measured by the carbonization rate measuring device and the carbonization degree evaluated by the carbonization degree evaluation unit are constant.

[0009] Here, it is preferable that the carbonization furnace has a temperature sensor that detects the temperature of the internal space, and the control device controls the atmospheric temperature in the internal space by controlling the amount of air supplied to the internal space based on the combustion temperature transmitted from the temperature sensor. It is also preferable that the carbonization furnace has a char level sensor that detects the amount of char discharged from the storage unit, and the control device controls the amount of char discharged from the storage unit according to the char level transmitted from the char level sensor.

[0010] It is also preferable that the carbonization furnace has a carbonization degree sensor that evaluates the carbonization degree based on the color of the carbonized material generated in the storage unit, and the control device controls the ratio of the carbonized material to the amount of raw material supplied according to the carbonization degree evaluated by the carbonization degree sensor. It is also preferable that the carbonization furnace has a turntable rotation speed sensor that detects the rotation speed of a turntable at the lower side of the storage unit from which the carbonized material is discharged, and the control device controls the discharge amount of the carbonized material discharged from the storage unit according to the rotation speed of the turntable detected by the turntable rotation speed sensor.

[0011] It is also preferable that the carbonization furnace has a raw material supply sensor that detects the amount of pellets supplied to the storage section, and the control device controls the pellets fed to the storage section in accordance with the amount of pellets detected by the raw material supply sensor so that the amount of char is 23% to 25% by weight. It is also preferable that the carbonization furnace has a pressure sensor that detects the pressure in the internal space, and the control device controls the pressure in the internal space to a negative pressure in accordance with the pressure detected by the pressure sensor.

[0012] The present invention also relates to a biomass power generation system comprising any one of the hydrogen production systems described above, and a power generation device that generates power using water gas produced by the hydrogen production system.

[0013] Furthermore, the present invention provides a biomass hydrogen supply system comprising any one of the hydrogen production systems described above and a hydrogen supply device that supplies hydrogen produced by the hydrogen production system. Effect of the Invention

[0014] In the hydrogen production system of the present invention thus configured, the carbonization furnace has an inlet for feeding pellets and chips, a storage section for storing the carbonized material fed from the inlet, an outlet for discharging the carbonized material produced by carbonizing the pellets and chips in the storage section, and a carbonization degree evaluation section for evaluating the carbonization degree of the carbonized material produced, and the control device controls the atmospheric temperature in the storage section so that the ratio of carbonized material measured by the carbonization rate measurement device and the carbonization degree evaluated by the carbonization degree evaluation section are constant. This allows the superheated steam to undergo an aqueous reaction using the high-temperature gas discharged from the carbonization furnace.

[0015] In particular, the control device controls the atmospheric temperature in the internal space by controlling the amount of air supplied to the internal space based on the combustion temperature transmitted from the temperature sensor. The control device also controls the amount of carbonized material discharged from the storage unit according to the level of carbonized material transmitted from the carbonized material level sensor. The control device also controls the ratio of carbonized material to the amount of raw material supplied according to the carbonization degree evaluated by the carbonization degree sensor. The control device also controls the amount of carbonized material discharged from the storage unit according to the number of rotations of the turntable detected by the turntable rotation speed sensor. The control device also controls the amount of carbonized material to be 23% by weight to 25% by weight with respect to the pellets or chips fed into the storage unit according to the amount of pellets or chips fed according to the amount of pellets or chips detected by the raw material feed sensor. The control device also controls the pressure in the internal space to be negative according to the pressure detected by the pressure sensor. Therefore, in any of these cases, the high-temperature gas discharged from the carbonization furnace can be used to cause the superheated steam to react with water in the same manner as above.

[0016] In addition, the biomass power generation system of the invention generates electricity using water gas produced by a hydrogen production system that efficiently generates pyrolysis gas with a uniform composition ratio, so it can stably rotate the generator engine, whose heat output is determined by the proportion of combustible gases (CO, H2) in the gas.

[0017] Furthermore, the biomass hydrogen supply system of the invention produces hydrogen using a hydrogen production system that efficiently generates pyrolysis gas with a uniform composition ratio, and supplies the hydrogen. Therefore, the system can be easily incorporated into on-site hydrogen stations that produce hydrogen using biomass and then fill fuel cell vehicles directly with hydrogen, as well as off-site hydrogen stations that transport hydrogen from the production site to another location. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a block diagram illustrating the configuration of a biomass power generation system and a biomass hydrogen supply system in which the hydrogen production system of the present embodiment is incorporated. [Diagram 2] FIG. 2 is a block diagram showing a specific configuration of a subcritical system. [Diagram 3] FIG. 1 is a schematic diagram illustrating the configuration of a biomass power generation system and a biomass hydrogen supply system incorporating the hydrogen production system of the present embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating the configuration of a biomass power generation system and a biomass hydrogen supply system in which the hydrogen production system of the present embodiment is incorporated, and is a continuation of FIG. [Diagram 5] FIG. 2 is a schematic vertical cross-sectional view showing the internal structure of a carbonization furnace. [Figure 6] FIG. 2 is a block diagram showing an example of a functional configuration of a carbonization furnace. [Figure 7] FIG. 2 is a block diagram illustrating a hydrogen supply facility. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram illustrating the configuration of a biomass power generation system and a biomass hydrogen supply system incorporating a hydrogen production system 1 of the present embodiment, Fig. 2 is a block diagram showing a specific configuration of a continuous subcritical system using subcritical water, and Figs. 3 and 4 are schematic diagrams illustrating the configuration of a biomass power generation system and a biomass hydrogen supply system incorporating a hydrogen production system 1 of the present embodiment.

[0020] The hydrogen production system 1 of this embodiment is an apparatus that generates water gas by recovering carbonized material from waste biomass (organic waste) such as food residue, paper diapers, food waste, and livestock manure sludge in a carbonization furnace and pyrolyzing and gasifying the carbonized material. The water gas generated by the hydrogen production system 1 is used for power generation as fuel for a gas generator 7, which is a power generation device, or is sent to a hydrogen supply facility 8, which is a hydrogen supply device, where hydrogen is produced and converted into hydrogen, and is used in fuel cell vehicles, household fuel cell cogeneration systems, and the like. For example, the gas generator 7 generates electricity using about 30% of the water gas generated by the hydrogen production system 1, and produces about 70% of the water gas generated by the hydrogen production system 1 to supply hydrogen.

[0021] First, a hydrogen production system 1 according to the present embodiment will be described. The hydrogen production system 1 is mainly composed of a subcritical system 2 that processes and supplies biomass, a carbonization furnace 3 that incompletely combusts and carbonizes the processed biomass, a superheated steam generator 4 that heats steam to generate superheated steam, a pyrolysis furnace 5 that generates pyrolysis gas, and a water gas recovery device 6 that cleans the pyrolysis gas and recovers water gas.

[0022] Organic waste and partially processed biomass are fed into the subcritical system 2 from a raw material supply line 21. The subcritical system 2 performs continuous subcritical treatment of the biomass and processes it into pellets. The organic waste broadly includes general waste such as food waste, paper diapers, livestock waste, and household garbage, such as food waste, paper diaper waste, and livestock waste. Although various organic wastes such as these can be used as raw materials for generating hydrogen, it is preferable to use biomass such as food waste, paper diapers, and livestock waste sludge (referred to as high-moisture biomass). Note that high-moisture biomass has a moisture content of about 70% to 80% by weight.

[0023] 2 is a block diagram showing a specific configuration of the subcritical system 2. The subcritical system 2 includes a subcritical mechanism 200 having a crushing section 210, a sorting section 220, a subcritical processing section 230, a holding section 240, a separating section 250, a pellet manufacturing section 260, a drying section 270, and a supplying section 280, and a subcritical control section 290 that controls each component of the subcritical mechanism 200.

[0024] The crushing unit 210 crushes the biomass, which is the raw material for the carbonized material, into small pieces. The crushing unit 210 is provided as a tank having, for example, a stirring rod 211 and a grinder 212, and the biomass is put into the tank.

[0025] In the crushing section 210, the biomass is stirred and mixed by a stirring rod 211, and further crushed by a crusher 212 to dimensions of about 5 mm square and 50 mm long. It is preferable that the crushing section 210 is composed of two tanks, and stirring and crushing are performed alternately in the two tanks. The biomass crushed in the crushing section 210 is supplied to the sorting section 220 by a conveyor (bucket conveyor).

[0026] The sorting unit 220 separates and removes metal components from non-metal components in the biomass crushed by the crushing unit 210. Specifically, the sorting unit 220 removes metal components, which are unnecessary materials, from the raw material to be turned into carbonized material as foreign matter from the transport path.

[0027] The sorting section 220 is, for example, a magnetic separator or an eddy current separator, and is provided to separate metals from non-ferrous materials. The sorting section 220 preferably has a two-layer structure, with the upper layer having a surface magnetic flux density of 1000 Gauss and the lower layer having a surface magnetic flux density of 3000 Gauss. The biomass from which the metal components have been removed after being sorted in the sorting section 220 is supplied to the subcritical processing section 230 by a conveyor.

[0028] The subcritical processing section 230 agitates the biomass from which metal and non-ferrous components have been removed by the sorting section 220, and generates a slurry using subcritical steam. Specifically, the subcritical processing section 230 hydrolyzes the biomass with pressurized and heated steam to generate a slurry as liquid biomass.

[0029] The subcritical processing section 230 is configured to have a cylindrical body section 231 and an elliptical or semispherical dome section 232 with an aspect ratio of 2:1 provided at both ends of the body section 231 in the vertical direction. Specifically, the subcritical processing section 230 is formed as a cylindrical tank extending in the vertical direction. With this configuration, the amount of biomass that can be accommodated can be increased compared to when the entire shape of the subcritical processing section 230 is formed into a spherical shape. The supply of biomass from the sorting section 220 to the subcritical processing section 230 is regulated by a first ball valve 233. In the subcritical processing section 230, the position of the liquid level of the biomass is measured by a liquid level gauge (not shown).

[0030] In the subcritical processing section 230, biomass containing about 70 to 80% by weight of moisture is stirred with subcritical steam by a stirrer (not shown) to generate a slurry. Here, the subcritical steam has, for example, a temperature of 200 to 230°C and a pressure of 2.0 to 3.0 MPa. Note that this steam is desirably supplied from, for example, a superheated steam generator 4 described below.

[0031] The atmospheric temperature inside the subcritical treatment section 230 is preferably about 200 to 250° C., more preferably about 200 to 230° C., and even more preferably 215° C. The pressure inside the subcritical treatment section 230 is more preferably about 2 to 5.0 MPa, more preferably about 2.0 to 3.0 MPa, and even more preferably 2.1 MPa. In the subcritical treatment section 230, the water-based biomass is held for a period of about 30 to 50 minutes to generate a slurry.

[0032] The slurry produced in the subcritical treatment section 230 is supplied to the holding section 240 while the supply amount is adjusted by the second ball valve 234. The holding section 240 holds the slurry produced in the subcritical treatment section 230 and releases the steam portion resulting from separation of the steam and liquid (superheating) as exhaust gas. The slurry held for a certain period in the holding section 240 is sent to the separation section 250 via a slurry pump.

[0033] The separation unit 250 reduces the moisture content of the slurry supplied from the holding unit 240 to 40% by weight or less to generate a solid component. Specifically, the separation unit 250 desalinates the slurry and separates the moisture to generate a solid component (dehydrated cake) whose moisture content has been reduced from 90% by weight to approximately 40% by weight.

[0034] The dehydrated cake produced in the separation section 250 contains salt. Therefore, the separation section 250 is preferably provided with a washing water supply section 251 that supplies washing water for washing the salt-containing dehydrated cake to remove the salt. By washing the dehydrated cake with washing water such as water, salt is removed from the dehydrated cake, which is a raw material for pellets. The solid components produced in the separation section 250 are supplied to the pellet production section 260 by a bucket conveyor.

[0035] The pellet production section 260 produces pellets from the solid components produced in the separation section 250. The pellet production section 260 produces pellets with a diameter of about 5 mm and a length of about 50 mm from dehydrated cake with a moisture content of about 40% by weight. The pellets produced in the pellet production section 260 are supplied to the drying section 270 by a bucket conveyor.

[0036] The drying section 270 dries the pellets or chips produced in the pellet production section 260. Specifically, the drying section 270 uses high-temperature exhaust gas generated in the carbonization furnace 3 to dry the pellets by controlling the rotation speed of the dryer with secondary radiant heat from hot air until the moisture content of the pellets reaches about 15% by weight as measured by a moisture content meter.

[0037] The supply unit 280 is a path for supplying pellets from the subcritical system 2 to the carbonization furnace 3, and the pellets dried in the drying unit 270 are supplied to the carbonization furnace 3 via the supply unit 280. The supply unit 280 is provided with a moisture meter 281 between the drying unit 270 and the carbonization furnace 3 to measure the moisture content of the pellets. The moisture meter 281 functions as a sensor to detect whether the moisture content of the pellets is about 15% by weight, for example. Note that the supply unit 280 does not necessarily need to be provided as a part of the subcritical system 2, and may be provided at any position in the hydrogen production system 1 as long as it is capable of supplying raw materials.

[0038] The subcritical control unit 290 controls continuous subcritical processing in each process from the input of biomass in the subcritical system 2 to the supply of pellets to the carbonization furnace 3.

[0039] 5 is a schematic vertical cross-sectional view showing the internal structure of the carbonization furnace 3. The carbonization furnace 3 is an apparatus for carbonizing organic waste to obtain a carbonized material. The carbonization furnace 3 is configured to include a storage section 301, a heating section 302, a turntable 303, an ignition section 304, a temperature sensor 311, a carbonized material level sensor 312, a carbonization degree sensor (carbonization degree evaluation section) 313, a turntable rotation speed sensor 314, a raw material supply sensor 315, and a pressure sensor 316. Various operations of the carbonization furnace 3 are controlled by a carbonization furnace control section 100 of the control device 90.

[0040] The storage section 301 is formed to extend in a substantially cylindrical shape along the axis X. The storage section 301 has an internal space 305 into which pellets are input, and is divided into three regions from the lower side: a lower region R1, a middle region R2, and an upper region R3. The storage section 301 is formed with an input port 301a, an outlet port 301b, an air supply port 301c, and an exhaust port 301d.

[0041] The inlet 301a is an opening for feeding pellets (organic matter) as raw material into the internal space 305. Pellets that have been dehydrated in the subcritical system 2 and dried in a dryer to a moisture content of 15% by weight or less are fed through the inlet 301a. The inlet 301a is formed on the upper side surface of the storage section 301. The amount of raw material fed into the internal space 305 through the inlet 301a is controlled by the carbonization furnace control section 100.

[0042] The discharge port 301b is an opening for discharging the charcoal from the internal space 305 to the outside. The discharge port 301b is formed on the lower side (bottom) of the storage section 301. The amount of the charcoal discharged from the internal space 305 through the discharge port 301b is controlled by the carbonization furnace control section 100.

[0043] The air supply port 301c is an opening for supplying air for combustion to the internal space 305. The air supply port 301c is formed on a side surface of the storage section 301 and is provided so as to be freely opened and closed with respect to the internal space 305. Since the air supply port 301c is freely opened and closed, the carbonization furnace control section 100 controls the amount of air supplied to the internal space 305.

[0044] Exhaust port 301d is an opening for discharging to the outside combustion gas generated in internal space 305. Exhaust port 301d is formed on a side surface of housing portion 301, and is provided so as to be freely opened and closed relative to internal space 305.

[0045] Heating section 302 is a section sandwiched between a cylindrical member protruding upward from the upper side of turntable 303 and accommodation section 301. Heating section 302 is provided so as to be about one-third the height from the lower side of accommodation section 301, and a gap is formed between heating section 302 and accommodation section 301. Heating section 302 is combusted by ignition section 304 when carbonization furnace 3 starts operating, and pellets put into internal space 305 are incompletely combusted to generate charcoal.

[0046] The turntable 303 is an annular rotating body provided below the storage unit 301. The turntable 303 rotates about an axis X by a motor controlled by the carbonization furnace control unit 100. As the turntable 303 rotates, the carbonized material is discharged from a discharge port 301b.

[0047] Ignition unit 304 is provided inside storage unit 301 and heats heating unit 302 and internal space 305. Ignition unit 304 is desirably provided on the lower side of storage unit 301 so as to be able to heat heating unit 302. Ignition unit 304 is, for example, a burner.

[0048] The temperature sensor 311 detects the temperature of the internal space 305. Specifically, the temperature sensor 311 is provided at a position corresponding to the middle region R2 inside the accommodation section 301, and detects the atmospheric temperature of the combustion gas in the middle region R2. The temperature sensor 311 may be provided at positions corresponding to the lower region R1 and the upper region R3 other than the position corresponding to the middle region R2.

[0049] The carbonized matter level sensor 312 detects the amount of carbonized matter discharged from the carbonization furnace 3 via the turntable 303. In addition, the carbonization degree sensor 313 evaluates the carbonization degree of the carbonized matter generated in the carbonization furnace 3 based on the color of the carbonized matter.

[0050] The turntable rotation speed sensor 314 detects the rotation speed of the turntable 303, from which the carbonized material is discharged below the carbonization furnace 3. The raw material supply sensor 315 detects the amount of pellets supplied to the carbonization furnace 3.

[0051] The pressure sensor 316 detects the pressure in the internal space 305. Specifically, the pressure sensor 316 detects whether or not the pressure inside the carbonization furnace 3 is a negative pressure of about −50 mmAg when the carbonization furnace 3 starts operating.

[0052] The carbonization furnace 3 is controlled by a control device 90 so that the process from the start to the end of operation is automated. The control device 90 has a carbonization furnace control unit 100, which controls the carbonization furnace 3 for automation.

[0053] 6 is a block diagram showing an example of the functional configuration of the carbonization furnace 3. The carbonization furnace control unit 100 is connected to various sensors, such as a temperature sensor 311, a char level sensor 312, a carbonization degree sensor 313, a turntable rotation speed sensor 314, a raw material supply sensor 315, and a pressure sensor 316, and information from these sensors is transmitted to the carbonization furnace control unit 100. The carbonization furnace control unit 100 is configured to include a temperature control unit 101, a char level control unit 102, a carbonization degree control unit 103, a carbonization rate control unit 104, and an ignition burner control unit 105.

[0054] The temperature control unit 101 controls the temperature in the carbonization furnace 3. Specifically, the temperature control unit 101 controls the amount of air supplied from the air supply port 301c based on the combustion temperature transmitted from the temperature sensor 311, thereby controlling the atmospheric temperature in the internal space 305. The temperature control unit 101 controls the atmospheric temperature in the oxygen-deficient state in the intermediate region R2 so that the carbonization rate of the carbonization rate measuring device 31 is about 23% by weight to 25% by weight.

[0055] When the carbonization furnace 3 is started, the ignition unit 304 is started, and when the temperature in the internal space 305 rises to about 800°C, the ignition unit 304 is stopped, the ignition burner is automatically removed, and the turntable 303 is rotated. When the carbonization furnace 3 is started, the pressure in the internal space 305 is negative pressure. The temperature control unit 101 controls the amount of air supplied from the air supply port 301c so that the atmospheric temperature in the lower region R1 is maintained at 350 to 400°C, the atmospheric temperature in the middle region R2 is maintained at about 1000°C (950 to 1050°C), and the atmospheric temperature in the upper region R3 is maintained at about 1150 to 1200°C. In order to control the amount of air supplied from the air supply port 301c, for example, the amount of air supplied from the primary air blower 361 and the secondary air blower 362 may be adjusted.

[0056] The carbonized material level control unit 102 controls the amount of carbonized material discharged from the carbonization furnace 3. The carbonization degree control unit 103 controls the carbonization degree of the carbonized material generated in the carbonization furnace 3 to be constant. The carbonization rate control unit 104 controls the carbonized material to be 23% to 25% by weight with respect to the pellets fed into the storage unit 301. The ignition burner control unit 105 controls the start and stop of the ignition unit 304 when the carbonization furnace 3 is started up.

[0057] In the carbonization furnace 3, charcoal containing approximately 92% by weight of carbon and high-temperature exhaust gas at 1150°C to 1200°C are generated by complete combustion. The charcoal is discharged from the bottom of the carbonization furnace 3, and after the quinker is separated, it is sent to a carbonization rate measuring device 31 via a conveyor. Meanwhile, the high-temperature exhaust gas is discharged from the top end of the carbonization furnace 3 and sent to the pyrolysis furnace 5 to be used as a heat source for the pyrolysis reaction.

[0058] In the hydrogen production system 1, the superheated steam that reacts with the carbide during the flow-type aqueous reaction in the center pipe 51 installed in the pyrolysis furnace 5 is heated by the superheated steam generator 4. Superheated steam is steam that is heated to a temperature above the saturation temperature. The temperature of the superheated steam supplied to the pyrolysis furnace 5 as a gasification agent is heated to about 800°C to 850°C.

[0059] The superheated steam generator 4 is mainly composed of a first steam superheater 41 and a second steam superheater 42. In the first steam superheater 41 and the second steam superheater 42, saturated steam is heated to generate superheated steam from the saturated steam.

[0060] Saturated steam generated by the process boiler 43 is supplied to the first steam superheater 41. In addition, water gas discharged from the pyrolysis furnace 5 is supplied to the first steam superheater 41. The temperature of the water gas supplied to the first steam superheater 41 is about 900°C to 1000°C.

[0061] The superheated steam discharged from the first steam superheater 41 through the second steam superheater 42 is supplied as a gasification agent to the pyrolysis furnace 5. In addition, the combustion gas used as a heat source for generating the superheated steam in the second steam superheater 42 is supplied to the process boiler 43.

[0062] In the process boiler 43, saturated steam of 2.2 MPaG or more is recovered, and superheated steam is produced in the first steam superheater 41 and the second steam superheater 42 at 800 to 850°C, which is then supplied to the pyrolysis furnace 5 for use in the aqueous reaction. At the same time, the steam is used in the subcritical treatment section 230. The steam is supplied at a steam pressure of 2.1 MPaG or more and a steam temperature of 215°C or more for hydrolysis.

[0063] Furthermore, the combustion exhaust gas recovered in the process boiler 43 is sent to the drying section 270 of the raw material supply line (subcritical system 2) as shown in Fig. 3, and is used to dry the biomass. Also, the exhaust gas generated from the drying section 270 is rendered harmless in the exhaust gas treatment facility 24 and released into the atmosphere.

[0064] The carbonized material from which clinker with a certain particle size or larger has been removed is supplied to a carbonization rate measuring device 31. The carbonization rate measuring device 31 is disposed downstream of the carbonization furnace 3 in the raw material supply line, and detects in real time whether the ratio of the generated carbonized material to the pellets contained in the storage section 301 is 23% by weight to 25% by weight. Specifically, the carbonization rate measuring device 31 functions as a level meter (load cell) that detects the weight of the pellets contained in the storage section 301.

[0065] The carbonized material, whose carbonization rate has been measured by the carbonization rate measuring device 31 and transported by the conveyor, is put into a receiving hopper 33. Thereafter, the oxygen contained in the air is replaced with inert nitrogen gas using nitrogen gas constantly supplied from a nitrogen replacement device (N2), and then the material is supplied to the pyrolysis furnace 5.

[0066] The pyrolysis furnace 5 is supplied with the carbonized material sent directly from the carbonization furnace 3 in this manner and the returned carbonized material sent from a recycle hopper 13, which will be described later. In addition, superheated steam is also supplied from the superheated steam generator 4, as described above.

[0067] As shown in Fig. 4, the pyrolysis furnace 5 of this embodiment includes a long center pipe 51 and a jacket portion 52 that covers the periphery of the center pipe 51. The center pipe 51 is formed of a cylindrical pipe having a length of 6 to 9 m. The length of the center pipe 51 is preferably about 8 m.

[0068] Since center pipe 51 will be exposed to high temperatures of over 1000° C., it is preferable to manufacture it from highly heat-resistant stainless steel such as SUS310. Jacket portion 52 is an outer cylinder that surrounds center pipe 51 with a gap between it and the outer periphery of center pipe 51.

[0069] Since high-temperature combustion exhaust gas at 1000°C to 1200°C passes through the gap between the inner surface of jacket portion 52 and the outer surface of center pipe 51, a heat-resistant material with a thickness of approximately 350 mm to 400 mm is attached to jacket portion 52.

[0070] Jacket portion 52 is formed to be shorter than center pipe 51. The portion of center pipe 51 protruding upward from jacket portion 52 becomes upper end portion 511, and the portion of center pipe 51 protruding downward from jacket portion 52 becomes lower end portion 512.

[0071] Further, an inlet 53 is provided near the upper end of the jacket portion 52 for taking in high-temperature exhaust gas, which is combustion exhaust gas generated in the carbonization furnace 3. The high-temperature exhaust gas that flows from the inlet 53 into the gap with the center pipe 51 is discharged from a discharge path 54 near the lower end of the jacket portion 52. The discharged combustion exhaust gas is supplied to the second steam superheater 42.

[0072] Center pipe 51, manufactured to a length of about 8 m, will stretch by about 160 mm to 190 mm due to the passage of high-temperature exhaust gas, so lower end 512 has a gland structure and upper end 511 is fixed.

[0073] The pyrolysis furnace 5 is a fluidized-bed pyrolysis gasification apparatus. Superheated steam generated by the above-mentioned superheated steam generator 4 is supplied from a steam supply port 513 near the end face of a lower end portion 512 of a center pipe 51.

[0074] Superheated steam is supplied so as to form an upward flow of 10 m / s to 15 m / s, which is greater than the terminal velocity of the charcoal. A return supply port 515 for supplying returned unreacted charcoal and a charcoal supply port 514 for supplying charcoal are provided about 100 mm to 200 mm above the steam supply port 513 at the lower end 512. Here, the charcoal supply port 514 is provided above the return supply port 515.

[0075] The carbonized material and unreacted coal supplied into the center pipe 51 from the carbonized material supply port 514 and the return supply port 515 rise within the center pipe 51 together with the superheated steam supplied from the steam supply port 513 below.

[0076] When the carbide and the superheated steam are brought into contact with each other and mixed, an aqueous reaction (thermal decomposition reaction) occurs, and aqueous gas (thermal decomposition gas) mainly composed of hydrogen gas (H2), carbon monoxide gas (CO), and carbon dioxide gas (CO2) is generated. For example, aqueous gas containing 60 volume % (V%) H2, 13 volume % CO, 25 volume % CO2, and about 2 volume % CH4 is generated and discharged from the thermal decomposition gas discharge port 516 at the upper end 511.

[0077] This aqueous reaction is an endothermic reaction overall, and the high-temperature exhaust gas of 1000°C to 1200°C supplied to the outer periphery of the center pipe 51 from the inlet 53 raises the temperature inside the center pipe 51 to 900°C to 1000°C due to radiant heat and the overall heat transfer coefficient.

[0078] Here, the aqueous reaction is as follows: C+H2O→CO+H2(1) C+H2O→CO2+H2(2)

[0079] The water-gas reaction shown in the above formula (1) is an endothermic reaction, and the water-gas shift reaction shown in formula (2) is an exothermic reaction. The amount of heat absorbed by the endothermic reaction shown in formula (1) is greater than the amount of heat generated by the exothermic reaction shown in formula (2). Therefore, the thermal decomposition reaction of the char and the superheated steam is an endothermic reaction overall.

[0080] Generally, at low temperatures (750℃-800℃), the exothermic water-gas shift reaction is promoted, and high-calorie carbon monoxide is consumed to produce low-calorie hydrogen, resulting in the production of hydrogen-rich pyrolysis gas with a low calorific value per unit volume. On the other hand, at high temperatures (900℃-1000℃), hydrogen-rich pyrolysis gas is produced. Also, the more superheated steam, which acts as a gasification agent, is supplied, the higher the H2 / CO ratio in the pyrolysis gas becomes.

[0081] By employing the fluidized pyrolysis furnace 5 as in this embodiment, the reaction area between the carbide and the superheated steam is increased, and the reaction rate can be increased. In other words, if the center pipe 51 is long, a sufficient reaction area for the aqueous reaction can be secured over the long distance of the upward movement. With the pyrolysis furnace 5 of this embodiment, the reaction rate can be increased to 80% by weight to 85% by weight (w%) of the supplied carbide.

[0082] The water gas (pyrolysis gas) discharged from the pyrolysis gas outlet 516 provided at the upper end 511 of the center pipe 51 of the pyrolysis furnace 5 is sent to the multi-cyclone 11 as shown in FIG.

[0083] In the multi-cyclone 11, the water gas is swirled inside to separate the residue contained in the water gas by centrifugation, and the residue is guided downward and supplied to the desuperheater 12. In the multi-cyclone 11, the water gas from which the residue has been removed is guided upward and supplied to the superheated steam generator 4.

[0084] Approximately 99% or more of the unreacted coal is separated in the multi-cyclone 11. The unreacted coal separated in the multi-cyclone 11 is cooled to 300°C to 400°C in the attemperator 12 by spraying liquid water from a water supply pump (TW). The cooled unreacted coal is then sent to a recycle hopper 13 or a surplus hopper 14.

[0085] By using such a return system, it is possible to return about 2 to 5 times the amount of unreacted coal of the supplied carbonized material to the pyrolysis furnace 5 as returned unreacted coal. In other words, it is possible to prevent the unreacted portion of the carbonized material from being wasted without being used to generate water gas, and the yield of water gas from the carbonized material is improved. In addition, the unreacted coal, which has had water gas replaced with inert nitrogen gas by the nitrogen replacement device (N2) and has been sent to the surplus hopper 14, is recovered.

[0086] Meanwhile, the water gas recovered in the multi-cyclone 11 is subjected to heat recovery (about 400°C) in the first steam superheater 41 and sent to the CO reformer 61. In the CO reformer 61, carbon monoxide (CO) and water vapor (H2O) are reacted on a catalyst to convert them into hydrogen (H2) and carbon dioxide (CO2). CO+H2O→CO2+H2(exothermic reaction)

[0087] The composition of the water gas reformed in the CO reformer 61 is approximately 65 volume % (V%) of H2, approximately 2 volume % of CO, approximately 31 volume % of CO2, and approximately 2 volume % of CH4, and is discharged. The reformed water gas is then sent to the water gas scrubber 62.

[0088] The water gas recovery apparatus 6 of this embodiment is mainly composed of a water gas scrubber 62, a circulation cooler 63, a water gas roots blower 64, and a water gas holder 65. The water gas recovery apparatus 6 may also include the above-mentioned CO reformer 61.

[0089] In the water gas scrubbing tower 62, the water gas sent in at a temperature of about 400° C. is cooled to about 40° C. The water gas is separated into cooled water gas and residue (unreacted coal) by cooling, and the unreacted coal is discharged outside the system and recovered.

[0090] A circulating cooler 63 that serves as a water gas cooling device is connected to the water gas cleaning tower 62, and by cleaning and cooling with liquid circulating water, the water gas discharged toward the water gas holder 65 can be cooled to approximately 40°C.

[0091] Here, a scrubbing tower pump 621 and a line filter 631 are interposed between the water gas scrubbing tower 62 and the circulation cooler 63. Also, in the circulation cooler 63, return water (RCW) of the cooling water (CW) supplied for scrubbing and cooling the water gas is recovered and circulated again by the circulation pump as cooling water for scrubbing and cooling the water gas.

[0092] The water gas treated in the water gas scrubber 62 is supplied to a water gas holder 65 by a water gas Roots blower 64. If a gas generator 7 is connected to the water gas holder 65, power is generated using the water gas and transmitted. If a gas generator 7 is connected to the water gas holder 65 of the hydrogen production system 1, it becomes a biomass power generation system.

[0093] The gas generator 7 is a power generating device that operates using water gas as fuel. As a power source for driving the gas generator 7, for example, a gas engine that operates by burning water gas is used.

[0094] On the other hand, if a hydrogen supply device, that is, a hydrogen supply equipment 8, is connected to the water gas holder 65 of the hydrogen production system 1, it becomes a biomass hydrogen supply system. The biomass power generation system and the biomass hydrogen supply system may be either one or the other, or a system equipped with both as shown in Figs. 1 and 4.

[0095] 4 is a block diagram illustrating an example of the hydrogen supply facility 8 constituting the biomass hydrogen supply system. The hydrogen supply facility 8 is mainly composed of a compressor 81 and a pressure accumulator .

[0096] In the hydrogen production system 1, the water gas supplied from the water gas holder 65 is pressurized to 0.9 MPaG, and hydrogen (H2) is produced by the pressurized adsorption method (PSA) so that the purity is 99.999% or more. In short, highly pure hydrogen gas is produced by removing components such as carbon monoxide gas and carbon dioxide gas contained in the water gas.

[0097] Hydrogen (H2) produced by the hydrogen production system 1 is compressed to 90 MPa by a compressor 81 and filled into a pressure accumulator 82. When hydrogen is to be supplied to a fuel cell vehicle FCV, the fuel cell vehicle FCV is connected to a dispenser 83, which is a filling machine, and hydrogen is filled into the tank. By using the dispenser 83, hydrogen gas can be supplied to the fuel cell vehicle FCV while controlling the flow rate and pressure.

[0098] On the other hand, when hydrogen gas is used for household fuel, for household fuel cell cogeneration systems, semiconductor manufacturing processes, fuel for various factories, power companies, etc., and is either connected to a biomass hydrogen supply system via piping or supplied at a different location, the hydrogen in the accumulator 82 is filled into a cylinder HGB, curdle, or truck via a cylinder filling device 84.

[0099] The control device 90 automatically executes a series of processes throughout the entire period from the start to the shutdown of the hydrogen production system 1. Specifically, the control device 90 automates the processes of each component provided on the path from the crushing section 210, where biomass is input, to the hydrogen supply facility 8, where hydrogen is supplied. Note that an example of control by the control device 90 is a distributed control system (DCS). Note that part of the distributed control system is omitted from illustration in Figs. 3 and 4.

[0100] Specifically, the control device 90 controls the stirring rod 211 and the crusher 212 provided in the crushing unit 210 by a motor so as to automatically crush the biomass supplied to the crushing unit 210. In addition, the control device 90 controls the magnetic flux density of the sorting unit 220 to separate metal components from the biomass.

[0101] The control device 90 also controls the temperature and pressure of the subcritical processing section 230 to be constant. Specifically, the control device 90 recovers steam generated in the process boiler 43 of the hydrogen production system 1 and controls the steam to be supplied to the subcritical processing section 230. The control device 90 also controls the timing at which the slurry is supplied from the holding section 240 so that the slurry generated in the subcritical processing section 230 is held in the holding section 240 for a certain period of time.

[0102] The control device 90 controls the water content of the slurry to be reduced from 90% by weight to about 40% by weight by centrifugation in the separation unit 250, and also controls the supply of washing water. The control device 90 also controls the supply of solid components in the pellet production unit 260.

[0103] The control device 90 also adjusts the number of drying units in the drying section 270 by inverter control and varies and controls the residence time so that the moisture content of the pellets decreases to 15% by weight or less based on data from the moisture meter 281. The control device 90 controls the supply of biomass such as slurry and pellets by controlling a motor provided on the transport path in the hydrogen production system 1 including the supply unit 280.

[0104] The control device 90 also outputs control signals to each component and performs overall control of the hydrogen production system 1. For example, the control device 90 controls a conveyor so that pellets are supplied from the carbonization furnace 3 to the pyrolysis furnace 5. The control device 90 supplies superheated steam generated by the superheated steam generator 4 to the pyrolysis furnace 5. The control device 90 controls the reaction rate of the supplied carbonized material in the pyrolysis furnace 5 to be within a range of 80% to 85% by weight.

[0105] Furthermore, the control device 90 controls the water gas to be sent from the pyrolysis furnace 5 to the multi-cyclone 11. In the multi-cyclone 11, the control device 90 centrifuges the residue contained in the water gas, and controls the separated unreacted coal to be supplied to the recycle hopper 13 or surplus hopper 14 via the attemperator 12. The control device 90 controls the water gas recovered in the multi-cyclone 11 to be sent to the CO reformer 61, and controls the water gas reformed in the CO reformer 61 to be sent to the water gas scrubbing tower 62. That is, each step of hydrogen production is continuously and automatically executed by the control device 90.

[0106] The subcritical system 2 thus configured processes biomass into pellets by continuous subcritical treatment, and includes a crushing section 210 for crushing the supplied biomass, a subcritical treatment section 230 for stirring the biomass crushed by the crushing section 210 and removing metal and non-ferrous metal components, and generating a slurry using subcritical steam, a separation section 250 for desalting the slurry generated by the subcritical treatment section 230 and separating water to generate a solid component, a pellet production section 260 for producing pellets from the solid component generated by the separation section 250, a drying section 270 for drying the pellets produced by the pellet production section 260, and a subcritical control section 290 for controlling the operations of the crushing section 210, the subcritical treatment section 230, the separation section 250, the pellet production section 260, and the drying section 270. That is, since each component constituting the subcritical system 2 is controlled by the subcritical control section 290, a series of processes from the input of raw materials to the supply of pellets can be performed continuously, automatically, and efficiently.

[0107] The subcritical processing section 230 has a cylindrical body section 231 and an elliptical or semispherical dome section 232 with an aspect ratio of 2:1 provided on both ends in the vertical direction of the body section 231. With this configuration, the capacity of the subcritical processing section 230 can be increased compared to a case where the subcritical processing section 230 is simply formed into a spherical shape.

[0108] The subcritical water vapor used in the subcritical processing section 230 has a temperature of 200 to 230° C. and a pressure of 2.0 to 3.0 MPa. This can improve the efficiency of water gas production in the hydrogen production system 1 where processing is performed continuously.

[0109] In addition, the separation unit 250 is provided with a washing water supply unit 251 that supplies washing water for removing salt from the solid components. Therefore, the produced pellets are washed with washing water for removing salt, so that a carbonized product that is substantially free of salt can be obtained.

[0110] In the hydrogen production system 1, each component of the subcritical system 2, the carbonization furnace 3, the carbonization rate measuring device 31, the superheated steam generator 4, the pyrolysis furnace 5, the water gas recovery device 6, etc. are controlled by, for example, a DCS signal from the control device 90. Therefore, there is no need to perform various processes manually, and a series of processes from the supply of raw materials to the generation of water gas can be performed continuously, automatically, and efficiently.

[0111] The carbonization furnace 3 has an inlet 301a through which pellets are introduced, a storage section 301 for carbonizing and storing the pellets, an outlet 301b for discharging the carbonized material, and a carbonization sensor 313 for evaluating the carbonization degree of the carbonized material, and the control device 90 can keep the carbonization degree of the carbonized material constant by controlling the atmospheric temperature in the storage section 301. In particular, in the carbonization furnace 3, the storage section 301 for storing the carbonized material is formed in a cylindrical shape extending in the vertical direction. In addition, the control device 90 automatically controls the ratio of the carbonized material to the amount of the raw material supplied (carbonization rate) to 23% by weight to 25% by weight according to the carbonization degree evaluated by the carbonization degree sensor 313, and automatically controls the atmospheric temperature in the lower region R1 to 350 to 400°C, the atmospheric temperature in the middle region R2 to 950 to 1050°C, and the atmospheric temperature in the upper region R3 to 1150 to 1200°C. This allows the carbonization degree of the carbonized material generated in the carbonization furnace 3 to be increased.

[0112] Furthermore, the biomass power generation system, which generates power using the water gas produced by the hydrogen production system 1, can stably rotate the engine of a generator, whose heat output is determined by the content of combustible gases (CO, H2) in the gas. Furthermore, impurities such as nitrogen, sulfur, and tar are removed in the carbonization furnace 3, so safe and efficient power can be supplied with high power generation efficiency. In short, the effective use of biomass not only saves energy and protects the natural environment, but is also economical.

[0113] Furthermore, a biomass hydrogen supply system that produces the water gas generated by the hydrogen production system 1 and supplies hydrogen can easily realize on-site hydrogen stations that can produce hydrogen using biomass and fill fuel cell vehicles (FCVs) directly with hydrogen, or off-site hydrogen stations that transport hydrogen from the production site to another location.

[0114] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention. [Explanation of symbols]

[0115] 1: Hydrogen production system 2: Subcritical system 210: Crushing section 230: Subcritical processing section 231: Torso 232: Dome section 250: Separation section 260: Pellet Manufacturing Department 270:Drying section 290: Subcritical control section 3: Carbonization furnace 31: Carbonization rate measuring device 301: Storage unit 301a: Inlet 301b: Outlet 313: Carbonization sensor (carbonization evaluation section) 4: Superheated steam generator 5:Pyrolysis furnace 6: Water gas recovery device 7: Gas generator (power generation equipment) 8: Hydrogen supply equipment (hydrogen supply device) 90: Control device

Claims

1. A hydrogen production system in which biomass is hydrolyzed using continuous subcritical water and processed into pellets, a carbonization furnace for carbonizing the pellets by incomplete combustion; a carbonization rate measuring device for measuring a ratio of incompletely combusted carbonized material to the carbonized material obtained by carbonization in the carbonization furnace; A superheated steam generator that heats water vapor to generate superheated steam; a pyrolysis furnace for heating the superheated steam supplied from the superheated steam generator and the carbonized material obtained by carbonization in the carbonization furnace by a combustion exhaust gas generated in the carbonization furnace to generate a pyrolysis gas; a water gas recovery device for recovering water gas by cleaning the pyrolysis gas generated in the pyrolysis furnace; a control device for controlling operations of the carbonization furnace, the superheated steam generator, the pyrolysis furnace, and the water gas recovery device; The carbonization furnace is An inlet through which the pellets are introduced; a storage section for storing the carbonized material introduced through the introduction port; a discharge port for discharging a carbonized material produced by carbonizing the pellets in the storage section; A carbonization degree evaluation unit that evaluates the carbonization degree of the generated carbonized material, A hydrogen production system characterized in that the control device controls the atmospheric temperature in the storage unit so that the ratio of carbonized matter measured by the carbonization rate measuring device and the carbonization degree evaluated by the carbonization degree evaluation unit are constant.

2. The carbonization furnace has a temperature sensor that detects the temperature of the internal space, 2. The hydrogen production system according to claim 1, wherein the control device controls the ambient temperature in the internal space by controlling the amount of air supplied to the internal space based on the combustion temperature transmitted from the temperature sensor.

3. The carbonization furnace has a carbonization level sensor that detects the amount of carbonization discharged from the storage section, The hydrogen production system according to claim 1 or 2, characterized in that the control device controls the amount of carbon discharged from the storage section depending on the carbon level transmitted from the carbon level sensor.

4. The carbonization furnace has a carbonization degree sensor that evaluates the carbonization degree based on the color of the carbonized material generated in the storage section, 3. The hydrogen production system according to claim 1, wherein the control device controls a ratio of the carbonized material to the amount of the raw material supplied in accordance with the carbonization degree evaluated by the carbonization degree sensor.

5. The carbonization furnace has a turntable rotation speed sensor that detects the rotation speed of a turntable through which the carbonized material is discharged below the storage section, 3. The hydrogen production system according to claim 1, wherein the control device controls the amount of carbonized matter discharged from the storage unit in accordance with the number of rotations of the turntable detected by the turntable rotation speed sensor.

6. The carbonization furnace has a raw material supply sensor that detects the amount of pellets supplied to the storage section, The hydrogen production system described in claim 1 or 2, characterized in that the control device controls the pellets fed into the storage section to contain 23% to 25% by weight of carbide, depending on the amount of pellets supplied detected by the raw material supply sensor.

7. The carbonization furnace has a pressure sensor that detects the pressure in the internal space, 3. The hydrogen production system according to claim 1, wherein the control device controls the pressure in the internal space to a negative pressure in response to the pressure detected by the pressure sensor.

8. The hydrogen production system according to claim 1 or 2, a power generation device that generates electricity using hydrogen produced by the hydrogen production system.

9. The hydrogen production system according to claim 1 or 2, and a hydrogen supply device that supplies hydrogen produced by the hydrogen production system.

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