Biomass fuel utilization system

Abstract

To provide an efficient biomass fuel utilization system that can use much biomass fuel.SOLUTION: A biomass fuel utilization system related to one embodiment includes: a gasification device that generates biogas from biomass; a biogas power generation device that generates electric power by using biogas; and a biomass combustion device burning biomass to generate steam. The biomass combustion device is configured to use exhaust gas discharged from the biogas power generation device as a heat source.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a biomass fuel utilization system. [Background technology]

[0002] A biomass gasification power generation system equipped with a gasification device that generates biogas from biomass fuel such as wood chips is known (Patent Document 1). It is said that high power generation efficiency can be achieved by generating electricity by supplying the biogas generated by gasification to an internal combustion engine such as a gas engine or gas turbine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-174392 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the current social climate where renewable energy is expected to be the main power source of the future, the need for biomass power generation using biomass as fuel is also increasing. Under such social circumstances, there is a demand for a biomass fuel utilization system that can utilize more biomass fuel and is efficient.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide an efficient biomass fuel utilization system that can utilize a larger amount of biomass fuel. [Means for solving the problem]

[0006] One aspect of the biomass fuel utilization system according to the present disclosure includes a gasification apparatus that produces biogas from biomass, a biogas power generation apparatus that generates electricity using the biogas, and a biomass combustion apparatus that burns the biomass to produce steam, and the biomass combustion apparatus is configured to use exhaust gas discharged from the biogas power generation apparatus as a heat source. Effect of the Invention

[0007] According to one aspect of the biomass fuel utilization system of the present disclosure, a biogas power generation system that generates electricity using biogas and a biomass combustion system that burns biomass to generate steam are included, so electricity and steam can be produced using biomass as fuel. In addition, the biomass combustion system uses exhaust gas discharged from the biogas power generation system as a heat source, so the thermal efficiency of the entire system can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a biomass fuel utilization system according to one embodiment. [Diagram 2] FIG. 1 is a block diagram of a biomass fuel utilization system according to one embodiment. [Diagram 3] FIG. 1 is a block diagram of a biomass fuel utilization system according to one embodiment. [Figure 4] 1 is a schematic diagram showing an overview of a gasification apparatus according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of components described in these embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions excluding the presence of other elements.

[0010] 1 to 3 are block diagrams of a biomass fuel utilization system 10 (10A, 10B, 10C) according to some embodiments. In FIG. 1 to FIG. 3, the biomass fuel utilization system 10 (10A to 10C) includes a gasification apparatus 12 that produces biogas from biomass, a biogas power generation apparatus 14 (14a, 14b) that generates power using the biogas produced in the gasification apparatus 12, and a biomass combustion apparatus 16 that burns biomass to generate steam. The biogas power generation apparatus 14 generates power using the biogas produced in the gasification apparatus 12 as a heat source. The biomass combustion apparatus 16 is configured to use exhaust gas discharged from the biogas power generation apparatus 14 as a heat source.

[0011] 1 to 3, the biogas power generation system 14 that generates electricity using biogas and the biomass combustion system 16 that burns biomass to generate steam are provided, so electricity and steam can be produced using biomass as fuel, and the utilization of biomass as a renewable energy source can be promoted. In addition, the biomass combustion system 16 uses the exhaust gas discharged from the biogas power generation system 14 as a heat source, so the thermal efficiency of the entire system can be improved.

[0012] 4, the gasification apparatus 12 includes a gasification furnace 50, a heat exchanger 52 that exchanges heat between combustion air a supplied to the gasification furnace 50 and biogas discharged from the gasification furnace, and a dust remover 54 that removes impurities from the biogas in the biogas flow path downstream of the heat exchanger 52. Since the combustion air a is preheated by the biomass in the heat exchanger 52, the thermal efficiency of the entire system can be improved. In addition, the dust remover 54 allows the biogas from which impurities have been removed to be supplied to the biogas power generation apparatus 14. In another embodiment, the gasification apparatus may be, for example, a gasification apparatus that produces biogas by methane fermentation of waste.

[0013] In one embodiment, for example, as shown in Figures 1 and 2, a gas engine 14 (14a) equipped with a generator can be used as the biogas power generation device 14. In this embodiment, a crankshaft provided on the gas engine is connected to a main shaft of the generator, and the crankshaft is rotated by combustion of biogas, thereby generating electricity in the generator.

[0014] In another embodiment, as shown in Fig. 3, a solid oxide fuel cell (SOFC) 14 (14b) can be used as the biogas power generation system 14. Biogas and air are supplied to the SOFC 14b. Depending on the state of trace components contained in the biogas, a scrubber or a desulfurization device may be provided as a pretreatment device for the biogas. In one embodiment, biogas and water may be supplied to the SOFC 14b, and hydrogen may be produced by a reforming reaction inside the SOFC 14b.

[0015] In the SOFC 14b, hydrogen in the biogas reacts with oxygen in the air to generate electricity. The exhaust gas discharged from the SOFC 14b after the reaction contains exhaust fuel and exhaust air, and the exhaust fuel is supplied from an exhaust gas passage 42 to the biomass combustor 16 as auxiliary fuel. A portion of the exhaust air is supplied from an exhaust gas passage 44 as combustion air for the biomass combustor 16, and the rest is supplied to the water heater 26 as a heat source for the water heater 26. In this specification, "exhaust gas discharged from an SOFC serving as the biomass combustor 16" refers to at least one of exhaust fuel and exhaust air.

[0016] In one embodiment, a boiler is used as the biomass combustion device 16. The boiler burns biomass to generate steam and utilizes the heat contained in the exhaust gas discharged from the biomass power generation device 14 as a heat source. In one embodiment, the exhaust gas discharged from the gas engine 14a is directly supplied to the biomass combustion device 16, whereby the unburned fuel components contained in the exhaust gas are burned and the heat contained in the exhaust gas can be utilized to increase the temperature inside the furnace. In one embodiment, the exhaust gas (exhaust fuel) discharged from the SOFC 14b is directly supplied to the biomass combustion device 16, whereby the unburned fuel components contained in the exhaust gas (exhaust fuel) are burned and the heat contained in the exhaust gas (exhaust fuel) can be utilized to increase the temperature inside the furnace.

[0017] In one embodiment, as shown in FIG. 1, during normal operation, electricity generated by the biomass fuel utilization system 10 (10A) is used as a power source for the biomass fuel utilization system 10 (10A).

[0018] In one embodiment, the biomass fuel utilization system 10 is configured so that the same type of biomass is supplied to the gasification device 12 and the biomass combustion device 16. This allows the sharing of facilities for handling biomass, such as storage and transportation, and fuel procurement routes, which reduces facility costs and allows for volume discounts when procuring fuel. Here, "the same type" means, for example, the same or different types in a broad classification, such as wood biomass, agricultural processing residues, waste, sludge, etc., and does not mean "the same type" in a finer classification, such as cypress or cedar, or chips or pellets within wood biomass.

[0019] 2 and 3, a power supply switching unit 18 is further provided which switches the supply destination of the electricity generated by the biogas power generation apparatus 14 (14a, 14b). The power supply switching unit 18 is configured to be capable of switching to a power distribution line 24 which can supply electricity to at least the biomass fuel utilization system 10 (10B, 10C) or a surrounding area 23 of the location of the biomass fuel utilization system 10 (10B, 10C).

[0020] In this embodiment, during normal operation, the electricity generated by the biogas power generation apparatus 14 (14a, 14b) is sent to the biomass fuel utilization system 10 (10B, 10C) via the power distribution line 20. This allows the electricity to be utilized as a power source for the biomass fuel utilization system itself, and, if necessary, the electricity generated by the biogas power generation apparatus 14 (14a, 14b) is supplied to the power distribution line 24 of the surrounding area 23 of the location via the power distribution line 22. Also, in an emergency (such as a disaster), the electricity generated by the biogas power generation apparatus 14 (14a, 14b) can be switched to be supplied to the power distribution line 24 of the surrounding area 23 of the location, if necessary.

[0021] 2 and 3, one embodiment further includes a water heater 26 that generates hot water using exhaust gas discharged from the biogas power generation apparatus 14 (14a, 14b) as a heat source, and a first hot water supply passage 28 that supplies the hot water generated by the water heater 26 to the biomass combustion apparatus 16. The hot water generated by the water heater 26 is supplied to the biomass combustion apparatus 16 via the first hot water supply passage 28 as feed water.

[0022] According to this embodiment, since it is equipped with the water heater 26 and the first hot water supply passage 28, hot water can be generated by effectively utilizing the heat contained in the exhaust gas discharged from the biogas power generation apparatus 14 (14a, 14b), and the generated hot water can be supplied to the biomass combustion apparatus 16 to generate steam, thereby improving the thermal efficiency of the entire system.

[0023] In one embodiment, as shown in Figures 2 and 3, the system further includes a second hot water supply flow path 30 that supplies hot water from the water heater 26 to a regional supply flow path 32 that can supply hot water to the surrounding area 23 where the biomass fuel utilization system 10 (10B, 10C) is located, and a hot water supply switching unit 34 for switching and supplying hot water to the first hot water supply flow path 28 or the second hot water supply flow path 30.

[0024] In this embodiment, during normal operation, hot water generated by water heater 26 is supplied to biomass combustion device 16 via first hot water supply flow path 28 and can be used as boiler feed water, and can be switched to a local supply flow path 32 that can supply hot water to the surrounding area 23 where biomass fuel utilization system 10 (10B, 10C) is located via a second hot water supply flow path 30, as necessary. In addition, in an emergency (such as a disaster), hot water can be supplied to the local supply flow path 32 as necessary.

[0025] 2 and 3, one embodiment includes a switching control unit 36 ​​that switches the power supply switching unit 18 to the power distribution line 24 side when a power outage is detected in the surrounding area 23 of the location of the biomass fuel utilization system 10 (10B, 10C). When a power outage occurs in the surrounding area 23 of the location of the biomass fuel utilization system 10 (10B, 10C) in an emergency (such as a disaster), the switching control unit 36 ​​can switch and supply power to the power distribution line 24 that can supply power to the surrounding area 23 of the location, making it possible to quickly contribute to the community in an emergency.

[0026] 2 and 3, in one embodiment, when a water outage is detected in the area 23 surrounding the location of the biomass fuel utilization system 10 (10B, 10C), the switching control unit 36 ​​controls the hot water supply switching unit 34 so that the hot water supply destination is the area supply flow path 32. As a result, in the event of an emergency (such as a disaster) when a water outage occurs in the area 23 surrounding the location, the switching control unit 36 ​​can switch and supply hot water to the area 23 surrounding the location. This makes it possible to quickly contribute to the area in an emergency.

[0027] 2 and 3, the switching control unit 36 ​​is configured to be able to control both the power supply switching unit 18 and the hot water supply switching unit 34. On the other hand, in another embodiment, the power supply switching unit 18 and the hot water supply switching unit 34 may be controlled by separate dedicated control units.

[0028] In the embodiment shown in FIG. 3, a portion of the exhaust air discharged as exhaust gas from the exhaust gas passage 42 in the biogas power generation apparatus 14 is supplied from the exhaust gas passage 42 to the biomass combustion apparatus 16 as combustion air, so that the heat contained in the exhaust air can be used to increase the temperature inside the furnace.

[0029] On the other hand, in another embodiment, exhaust air is not supplied to the biomass combustor 16 from the exhaust gas passage 42, and all of the exhaust air discharged from the biogas power generation plant 14 (14b) may be supplied to the water heater 26 via the exhaust gas passage 44. In this case, hot water generated in the water heater 26 using this exhaust air as a heat source is supplied to the biomass combustor 16 via the first hot water supply passage 28, and is further heated by burning biomass to produce steam. The exhaust air after generating hot water in the water heater 26 may be supplied to the biomass combustor 16 as combustion air via the exhaust gas passage 46 in FIG. 3.

[0030] In one embodiment, as shown in Figs. 2 and 3, the system further includes a steam turbine 38 that generates electricity using steam generated by the biomass combustion device 16. The main shaft of the steam turbine 38 is connected to a generator 40, and the generator 40 generates electricity by rotating the main shaft. In this embodiment, since the steam turbine 38 generates electricity in addition to the biogas power generation device 14 (14b), the amount of electricity generated by the entire system can be increased. If the gasification device 12 and the biogas power generation device 14 (14b) are not included, it is necessary to purchase commercial electricity for auxiliary power at the start of the system until the steam turbine 38 starts generating electricity. In contrast, if the gasification device 12 and the biogas power generation device 14 (14b) are included as in this embodiment, the power generated by the biogas power generation device 14 (14b) is used for auxiliary power at the start, so that the use of commercial electricity can be suppressed. In addition, even after the system has transitioned to a stable state, the power generated by the biogas power generation device 14 (14b) continues to cover the auxiliary power, so that the amount of electricity generated by the steam turbine 38 is not consumed for the auxiliary power. In other words, it will be possible to suppress the reduction in the amount of electricity transmitted (sold) to the commercial grid.

[0031] 2 and 3 includes a power storage device 56. In this embodiment, surplus power generated by the biogas power generation system 14 (14b) and the steam turbine 38 is stored in the storage device. Therefore, even if biomass fuel cannot be procured in an emergency (such as a disaster), the power stored in the power storage device 56 can be supplied to the gasification system 12, the biogas power generation system 14 (14b), the biomass combustion system 16, etc., allowing the system to start up smoothly.

[0032] In one embodiment, woody biomass is used as the raw material biomass. Woody biomass is an easily obtainable biomass. In addition, since woody biomass is soft, it is easy to process into wood chips and the like. Therefore, even if the supply of biomass is interrupted in an emergency (such as a disaster), the operation of the biomass fuel utilization system 10 can be continued by procuring woody biomass from the surrounding area 23 where the system is located.

[0033] The contents described in each of the above embodiments can be understood, for example, as follows.

[0034] 1) One embodiment of a biomass fuel utilization system includes a gasification apparatus (12) that produces biogas from biomass, a biogas power generation apparatus (14) that generates electricity using the biogas, and a biomass combustion apparatus (16) that combusts the biomass to produce steam, and the biomass combustion apparatus (16) is configured to use exhaust gas discharged from the biogas power generation apparatus (14) as a heat source.

[0035] According to this configuration, since the biogas power generation system that generates electricity using biogas and the biomass combustion system that burns biomass to generate steam are included, electricity and steam can be produced using biomass as fuel, and the utilization of biomass as a renewable energy source can be promoted. In addition, since the biomass combustion system uses the exhaust gas discharged from the biogas power generation system as a heat source, the thermal efficiency of the entire system can be improved.

[0036] 2) A biomass fuel utilization system according to another aspect is the biomass fuel utilization system described in 1), which is configured so that the same type of biomass is supplied to the gasification apparatus (12) and the biomass combustion apparatus (16).

[0037] This configuration makes it possible to share facilities for storing and transporting biomass and fuel procurement routes, thereby reducing facility costs. In addition, by procuring the same type of biomass, volume discounts are possible when procuring fuel.

[0038] 3) A biomass fuel utilization system according to still another embodiment is the biomass fuel utilization system described in 1) or 2), which further includes a power supply switching unit (18) that switches the supply destination of the electricity generated by the biogas power generation device (14), and the power supply switching unit (18) is configured to be able to switch and supply electricity to a grid distribution line (24) that can supply electricity at least to the biomass fuel utilization system (10) or a surrounding area (23) where the biomass fuel utilization system (10) is located.

[0039] According to this configuration, during normal operation, the electricity generated by the biogas power generation device can be used as a power source for the biomass fuel utilization system itself, and can be supplied to a power distribution line capable of supplying electricity to the area surrounding the location of the biomass fuel utilization system as needed. Also, in an emergency (such as a disaster), electricity can be switched to the power distribution line as needed.

[0040] 4) A biomass fuel utilization system according to yet another embodiment is a biomass fuel utilization system according to any one of 1) to 3), further including a water heater (26) that generates hot water using exhaust gas discharged from the biogas power generation system (14) as a heat source, and a first hot water supply flow path (28) that supplies the hot water from the water heater (26) to the biomass combustion system (16).

[0041] With this configuration, the water heater can generate hot water by effectively utilizing the heat contained in the exhaust gas discharged from the biomass combustion device, and the generated hot water can be supplied to the biomass combustion device to generate steam. In other words, the exhaust gas discharged from the biogas power generation device is used as a heat source to heat the boiler feed water, thereby indirectly using the exhaust gas discharged from the biogas power generation device as a heat source. This improves the thermal efficiency of the entire system.

[0042] 5) In yet another aspect, the biomass fuel utilization system is the biomass fuel utilization system described in 4), further including a second hot water supply flow path (30) that supplies the hot water from the water heater (28) to a regional supply flow path (32) that can supply the hot water to a surrounding area (23) where the biomass fuel utilization system (10) is located, and a hot water supply switching unit (34) that switches the supply of the hot water to the first hot water supply flow path (28) or the second hot water supply flow path (30).

[0043] According to this configuration, during normal operation, as described above, the hot water generated by the water heater can be used as boiler feed water via the first hot water supply flow path, and when necessary, the hot water can be switched to be supplied to the surrounding area of ​​the location of the biomass fuel utilization system via the second hot water supply flow path. Also, in an emergency (such as a disaster), hot water can be supplied to the surrounding area of ​​the location of the biomass fuel utilization system when necessary.

[0044] 6) In yet another aspect, the biomass fuel utilization system is the biomass fuel utilization system described in 3), further comprising a power switching control unit (36) that switches the power supply switching unit (18) to the grid distribution line (24) when a power outage is detected in a surrounding area (23) where the biomass fuel utilization system (10) is located.

[0045] According to this configuration, in the event of a power outage in the area surrounding the location of the biomass fuel utilization system in an emergency (such as a disaster), the power switching control unit can switch power to the area surrounding the location of the biomass fuel utilization system, making it possible to contribute to the local area quickly in the event of an emergency.

[0046] 7) In yet another aspect, the biomass fuel utilization system is the biomass fuel utilization system described in 5), which includes a hot water switching control unit (36) that switches the hot water supply switching unit (34) to the second hot water supply flow path (30) when a water outage is detected in the area surrounding the location of the biomass fuel utilization system (10).

[0047] According to this configuration, in the event of an emergency (such as a disaster) when the water supply is cut off in the area surrounding the location of the biomass fuel utilization system, the hot water switching control unit can switch to supply hot water to the area surrounding the location of the biomass fuel utilization system, making it possible to contribute to the local area quickly in the event of an emergency.

[0048] 8) A biomass fuel utilization system according to yet another aspect is the biomass fuel utilization system described in any one of 1) to 7), further including a steam turbine (38) that generates electricity using steam generated in the biomass combustion device (16).

[0049] According to this configuration, since power is generated not only by the biogas power generation system but also by the steam turbine, the amount of power generated by the entire system can be increased. Furthermore, if the gasification system and biogas power generation system are not provided, when the system is started up, it is necessary to purchase commercial power for auxiliary power until the steam turbine starts generating power. In contrast, when the gasification system and biogas power generation system are provided as in the above embodiment, the power generated by the biogas power generation system is used for auxiliary power at start-up, thereby making it possible to reduce the use of commercial power. Furthermore, even after the system has transitioned to a stable operating state, the power generated by the biogas power generation system continues to cover the auxiliary power, so that the power generated by the steam turbine is not consumed by the auxiliary power. In other words, it is possible to prevent a reduction in the amount of power transmitted (sold) to the commercial grid.

[0050] 9) A biomass fuel utilization system according to yet another embodiment is a biomass fuel utilization system according to any one of 1) to 8), in which the biomass is woody biomass.

[0051] According to this configuration, woody biomass is easy to obtain as biomass. Also, because woody biomass is soft, it is easy to process it into wood chips, etc. Therefore, even if the supply of biomass is interrupted due to road closures in an emergency, the operation of the biomass fuel utilization system can be continued by procuring wood chips from the area surrounding the system's location. [Explanation of symbols]

[0052] 10 (10A, 10B, 10C) Biomass fuel utilization system 12 Gasifier 14 (14a, 14b) Biogas power generation equipment 16 Biomass Combustion Equipment 18 Power supply switching unit 20, 22 Power distribution lines 23 Location Surrounding Area 24 Grid distribution lines 26 Water heater 28 First hot water supply channel 30 Second hot water supply channel 32 Regional Supply Channel 34 Hot water supply switching unit 36 Switching control section 38 Steam Turbine 40 Generator 42, 44, 46 Exhaust gas flow path 50 Gasifier 52 Heat exchanger 54 Dust removal equipment 56 Energy storage device a Combustion air

Claims

1. A gasifier for producing biogas from biomass; A biogas power generation device that generates electricity using the biogas; A biomass combustion device that burns the biomass to generate steam; Equipped with The biomass combustion device is configured to utilize exhaust gas discharged from the biogas power generation device as a heat source, A water heater that generates hot water using exhaust gas discharged from the biogas power generation system as a heat source; A first hot water supply flow path that supplies the hot water from the water heater to the biomass combustion apparatus; Further comprising: Biomass fuel utilization system.

2. The gasification apparatus and the biomass combustion apparatus are configured to be supplied with the same type of biomass; The biomass fuel utilization system according to claim 1 .

3. The biogas power generation system further includes a power supply switching unit that switches the supply destination of the power generated by the biogas power generation system, The power supply switching unit is configured to be able to switch to a power distribution line capable of supplying power to at least the biomass fuel utilization system or a surrounding area of ​​the location of the biomass fuel utilization system, The biomass fuel utilization system according to claim 1 or 2.

4. A second hot water supply flow path that supplies the hot water from the water heater to a local supply flow path that can supply the hot water to a surrounding area where the biomass fuel utilization system is located; a hot water supply switching unit for switching and supplying the hot water to the first hot water supply flow path or the second hot water supply flow path; Further comprising: A biomass fuel utilization system according to any one of claims 1 to 3.

5. A gasification apparatus for producing biogas from biomass; A biogas power generation device that generates electricity using the biogas; A biomass combustion device that burns the biomass to generate steam; Equipped with The biomass combustion device is configured to utilize exhaust gas discharged from the biogas power generation device as a heat source, The biogas power generation system further includes a power supply switching unit that switches the supply destination of the power generated by the biogas power generation system, The power supply switching unit is configured to be able to switch to a power distribution line capable of supplying power to at least the biomass fuel utilization system or a surrounding area of ​​the location of the biomass fuel utilization system, and a power switching control unit that switches the power supply switching unit to the power grid side when a power outage is detected in the area surrounding the location of the biomass fuel utilization system. Biomass fuel utilization system.

6. A hot water switching control unit is provided that switches the hot water supply switching unit to the second hot water supply flow path when a water outage is detected in the surrounding area where the biomass fuel utilization system is located. The biomass fuel utilization system according to claim 4.

7. Further comprising a steam turbine that generates electricity using steam generated in the biomass combustion apparatus. A biomass fuel utilization system according to any one of claims 1 to 6.

8. The biomass is woody biomass. A biomass fuel utilization system according to any one of claims 1 to 7.

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