Floating watercraft

Abstract

The objective is to provide a floating facility for producing ethanol. [Solution] The floating watercraft 1 comprises a plurality of fermentation tanks 11 for storing crushed aquatic plants for fermentation, and a control unit that selects two fermentation tanks 11 from the plurality of fermentation tanks 11 and controls the attitude by transferring the contents between the two selected fermentation tanks 11.

Description

Technical Field

[0001] The present invention relates to a floating facility for producing ethanol.

Background Art

[0002] Generally, floating facilities handling fossil fuels are known. For example, an FSRU (floating storage regasification unit) that suppresses the impact on the natural environment is disclosed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, from the perspective of reducing carbon dioxide emissions, which are a concern for the global environment, a fuel alternative to fossil fuels is required. An object of an embodiment of the present invention is to provide a floating facility for producing ethanol.

Means for Solving the Problems

[0005] A floating facility according to an aspect of the present invention includes a plurality of fermentation tanks for storing plants living in water to be fermented after being crushed, and a control unit that selects two fermentation tanks from the plurality of fermentation tanks and controls the attitude by transferring the contents between the two selected fermentation tanks.

Effects of the Invention

[0006] According to an embodiment of the present invention, a floating facility for producing ethanol is provided.

Brief Description of the Drawings

[0007] [Figure 1] A side view showing the configuration of a floating watercraft according to an embodiment of the present invention. [Figure 2] A top view showing the configuration below the deck of the floating watercraft according to this embodiment. [Figure 3] This flowchart shows the flow of the bioethanol production method using a floating water-based facility according to this embodiment. [Figure 4] This flowchart shows the flow of the attitude control method for controlling the attitude of a floating watercraft according to this embodiment. [Figure 5] This diagram shows the configuration of a carbon dioxide sequestration system for fixing carbon dioxide in the sea in a floating facility according to this embodiment. [Modes for carrying out the invention]

[0008] (Embodiment) Figure 1 is a side view showing the configuration of a floating watercraft 1 according to an embodiment of the present invention. Figure 2 is a top view showing the internal configuration of the floating watercraft 1 according to this embodiment. The same parts in the drawings are denoted by the same reference numerals, and redundant explanations are omitted as appropriate.

[0009] The floating watercraft 1 is a facility for producing bioethanol. For example, the floating watercraft 1 is an FPSO (floating production storage and offloading unit) that produces bioethanol. Hereafter, bioethanol may be simply referred to as ethanol. The floating watercraft 1 may be configured as a vessel with propulsion capabilities. The floating watercraft 1 may be newly manufactured or modified from an existing vessel. For example, the floating watercraft 1 is intended to be a modification of a VLCC (very large crude oil carrier). Here, the configuration of the floating watercraft 1 in the shape of a vessel will be described. The fuel for the floating watercraft 1 can be self-supplied by using ethanol. However, the fuel for the floating watercraft 1 is not limited to ethanol; any fuel may be used.

[0010] Furthermore, while the floating watercraft 1 is described as a facility located on the sea that produces ethanol using seaweed as a raw material, it is not limited to this. The floating watercraft 1 may also be located on a river or lake. In addition, the raw material for ethanol is not limited to seaweed or seagrass, but can be any plant that inhabits water in the natural environment such as the sea, river, or lake. For example, seaweed that can be used as a raw material includes kelp, wakame, Sargassum, Sargassum fuciformis, or giant kelp. Sargassum, giant kelp, or Sargassum fuciformis are suitable as raw materials for ethanol because they grow quickly, and are easy to secure as raw materials because they are not suitable for consumption.

[0011] The floating watercraft 1 comprises a harvesting device 2, a washing unit 3, a pre-crushing storage unit 4, a crusher 5, a first centrifugal separator 6, a second centrifugal separator 7, a distillation column 8, and a hull 10. The harvesting device 2, washing unit 3, pre-crushing storage unit 4, crusher 5, first centrifugal separator 6, second centrifugal separator 7, and distillation column 8 are mounted on a deck located on the upper surface of the hull 10. The hull 10 is equipped with multiple fermentation tanks 11, a residue tank 12, an ethanol tank 13, a pump 31, and an ethanol pump 34.

[0012] The floating watercraft 1 is primarily controlled by a computer. The computer may consist of multiple computers, and some or all of them may be connected via a network. Each component may have a built-in control computer, or some components may not be controlled by a computer. For example, the computer may include an integrated automation system (IAS) and a loading computer that monitor and control the attitude of the floating watercraft 1.

[0013] The harvesting device 2 harvests seaweed, which is a raw material for ethanol, and takes it into the floating facility 1 on water. For example, the harvesting device 2 is provided near the bow FP. The harvesting device 2 may be arranged in any way and may be any device as long as it can take seaweed into the floating facility 1 on water. For example, the harvesting device 2 is a device in the form of a crane.

[0014] The washing section 3 is a place where equipment for washing the seaweed lifted from the sea with water such as seawater or fresh water is arranged. The washing section 3 removes the attachments of the seaweed by washing the seaweed. Note that the washing section 3 may be omitted. For example, the seaweed may be washed manually or using equipment carried in from outside the floating facility 1 on water.

[0015] The pre-crushing storage section 4 is a place for storing the seaweed washed by the washing section 3. For example, the pre-crushing storage section 4 is a tank for storing the seaweed before crushing. Note that the pre-crushing storage section 4 may be omitted.

[0016] The crusher 5 sequentially takes in the seaweed stored in the pre-crushing storage section 4 and finely crushes it. The crusher 5 sends the crushed seaweed into the first centrifuge 6.

[0017] The first centrifuge 6 removes moisture from the seaweed crushed by the crusher 5. In this way, in order to effectively utilize the capacity of the fermentation tank 11 provided in the limited space of the hull 10, the volume of the seaweed is reduced. The seaweed dehydrated by the first centrifuge 6 is stored in the fermentation tank 11 together with the substances for fermentation. The substances for fermentation are saccharifying yeast and enzymes. Thereby, the seaweed is fermented in the fermentation tank 11 for several days (for example, 14 days), and a fermentation broth is produced.

[0018] Note that as long as moisture can be removed from the seaweed, any device may be used and any treatment may be performed on the seaweed, not limited to a centrifuge. Also, the substances for fermentation may be changed or added according to the raw materials.

[0019] The second centrifuge 7 removes the residue of the fermented liquid that has been sufficiently fermented in the fermentation tank 11. Note that as long as the residue can be removed from the fermented liquid, any device may be used and any treatment may be performed, not limited to a centrifuge.

[0020] The distillation column 8 distills the fermented liquid to finally produce ethanol. Note that any distillation method may be adopted for the distillation of the fermented liquid, and any device or the like may be used.

[0021] Referring to FIG. 2, the specific configuration below the deck of the hull 10 will be described. The hull 10 includes a plurality of fermentation tanks 11, a residue tank 12, an ethanol tank 13, a seaweed pipe 21, a fermented liquid pipe 22, an emergency pipe 23, intermediate valves 24, 25, an emergency valve 26, a pump 31, valves 32, 33, and an ethanol pump 34.

[0022] The fermentation tank 11 is a tank for storing seaweed for a predetermined period for fermentation. The number of fermentation tanks 11 is determined according to the fermentation period and the unit period for managing fermentation. For example, if the minimum fermentation days of seaweed (the minimum number of days required for fermentation) is 14 days, and one fermentation tank 11 is provided for each fermentation elapsed days, which is the number of days elapsed from the injection date of seaweed, at least 14 fermentation tanks 11 are required. Since seaweed is put into the fermentation tank, it is desirable to apply rust-proof paint.

[0023] In addition, the fermentation tank 11 also functions as a ballast tank for controlling the attitude of the floating facility 1 on the water. When the fermentation tank 11 functions as a ballast tank, the capacities of all the fermentation tanks 11 may be the same. Thereby, the calculation for attitude control can be made easier.

[0024] Furthermore, one fermentation tank 11 may be assigned to a fermentation period of two days or more, or two or more fermentation tanks 11 may be assigned to the same fermentation period. In addition, the fermentation tanks 11 may be managed based on the fermentation time elapsed from the time the seaweed was injected (for example, 8 hours, 12 hours, 24 hours, or 36 hours).

[0025] Furthermore, extra fermentation tanks 11 may be provided as backups. For example, the backup fermentation tanks 11 may be used at all times to ferment seaweed for a period exceeding the minimum fermentation period, or they may be left empty during normal times and used only in emergencies (for example, during attitude control).

[0026] This section primarily describes a configuration where the minimum fermentation period is 14 days, with one fermentation tank 11 provided for each day of fermentation, and an additional fermentation tank 11 provided as a backup. Therefore, the floating watercraft 1 is equipped with a total of 15 fermentation tanks 11. Furthermore, the seaweed is fermented for 15 days, in addition to the minimum fermentation period of 14 days.

[0027] The residue tank 12 is a tank for storing the residue removed from the fermentation liquid. The ethanol tank 13 is a tank for storing bioethanol produced in the floating equipment 1. The residue tank 12 and the ethanol tank 13 may be located anywhere on the hull 10, or they may be located on the deck. For example, the residue tank 12 and the ethanol tank 13 may be located on the stern AP side of the hull 10.

[0028] A pump 31 is provided in each fermentation tank 11. Each pump 31 is connected to the fermentation liquid piping 22 via a valve 32. The pump 31 is a device for sending the fermentation liquid, which is produced by fermenting seaweed, from the fermentation tank 11 through the fermentation liquid piping 22 to the second centrifuge 7. The pump 31 may also be used to agitate the contents of the fermentation tank 11, such as the seaweed and fermentation liquid. This promotes the fermentation of the seaweed. In other words, the pump 31 has the function of sweeping out and circulating the contents of the fermentation tank 11.

[0029] The pump 31 may be centrally located rather than being installed in each fermentation tank 11. For example, a pump chamber may be provided behind the fermentation tank 11, and the pumps 31 may be integrated into this chamber. The fermentation liquid piping 22 may also be located at the bottom of the fermentation tank 11.

[0030] The ethanol pump 34 is installed in the ethanol tank 13. The ethanol pump 34 is a device for transferring ethanol stored in the ethanol tank 13 overboard. The ethanol pump 34 is used when the ethanol is shipped as a product.

[0031] The seaweed piping 21 is connected to each fermentation tank 11 via valves 33. The seaweed piping 21 is used to send seaweed to the fermentation tanks 11 before fermentation. By opening the valve 33 on the piping to the target fermentation tank 11 and closing the other valves 33, the seaweed introduced into the seaweed piping 21 is introduced into the target fermentation tank 11. An intermediate valve 24 is provided in the central part of the seaweed piping 21 in the longitudinal direction, but it is not required.

[0032] The fermentation liquid pipe 22 is used to extract the fermentation liquid obtained by fermenting seaweed from the fermentation tank 11. The valve 33, located in the pipe connecting the pump 31 (located in the fermentation tank 11) to the fermentation liquid pipe 22, is opened to activate the pump 31. This allows the fermentation liquid stored in a specific fermentation tank 11 to be extracted via the fermentation liquid pipe 22. An intermediate valve 25 is provided in the central longitudinal portion of the fermentation liquid pipe 22, but it is not required.

[0033] Emergency piping 23 is provided to connect the bow FP-side end of seaweed piping 21 and the bow FP-side end of fermentation liquid piping 22. Emergency valve 26 is provided on emergency piping 23. Emergency valve 26 is normally closed. By opening emergency valve 26, seaweed piping 21 and fermentation liquid piping 22 are connected by emergency piping 23, making it possible to transfer the contents of any two fermentation tanks 11 to each other. This allows the fermentation tanks 11 to function as ballast tanks. Alternatively, instead of emergency piping 23, a dedicated pipe for transferring the contents of any two fermentation tanks 11 to each other may be provided separately from seaweed piping 21 and fermentation liquid piping 22.

[0034] If an abnormality in the posture of the floating watercraft 1 is detected, the system controls the floating watercraft 1 to return to a normal posture by transferring some or all of the contents of one fermentation tank 11 to the other fermentation tank 11. The emergency piping 23 is used when transferring contents between the two fermentation tanks 11 in this manner.

[0035] Furthermore, by closing at least one of the intermediate valves 24 and 25 of the seaweed pipe 21 and the fermentation liquid pipe 22, the contents can be transferred between the two fermentation tanks 11, while the seaweed pipe 21 or the fermentation liquid pipe 22 can perform their original functions of taking in seaweed or taking out fermentation liquid. Specifically, the seaweed pipe 21 and the fermentation liquid pipe 22 on the emergency pipe 23 side are used to transfer the contents between the two fermentation tanks 11, and the seaweed pipe 21 or the fermentation liquid pipe 22 on the opposite side of the emergency pipe 23 are used to inject seaweed into the fermentation tank 11 or to take out fermentation liquid from the fermentation tank 11.

[0036] Referring to Figure 3, the method for producing bioethanol using the floating watercraft 1 will be explained.

[0037] Seaweed, which is the raw material for ethanol, is harvested by the harvesting device 2 (step S101). For example, there may be many seaweed shelves (cultivation shelves) for seaweed cultivation near the floating water facility 1. The harvesting device 2 harvests the seaweed by winding up a string to which multiple seaweed shelves are connected. In addition, by separating the seaweed from the seaweed shelf while leaving the roots of the seaweed on the shelf and returning the seaweed shelf with the remaining roots to the sea, new seaweed will grow from the roots of the seaweed shelf. In this way, seaweed can be harvested repeatedly from the seaweed shelf.

[0038] The harvested seaweed is washed in the washing section 3 to remove any attached organisms (step S102). For example, the seaweed is washed with seawater and then with fresh water. In addition to washing with water, the seaweed may also be treated to remove attached organisms. For example, attached organisms may include sand, mud, dirt, salt, or fish eggs.

[0039] The seaweed from which attached material has been removed is temporarily stored in the pre-crushing storage section 4. The seaweed stored in the pre-crushing storage section 4 is taken out sequentially and finely crushed by the crusher 5 (step S103). The seaweed is crushed to a degree that it does not hinder its flow through the seaweed piping 21. It is desirable that the seaweed be crushed to a fluid state.

[0040] The crushed seaweed is dehydrated by the first centrifuge 6 (step S104). This reduces the volume of the seaweed by the amount of water removed. The dehydrated seaweed is then injected into the fermentation tank 11 along with fermentation substances such as saccharifying yeast and enzymes (step S105). The fermentation substances may be injected into the fermentation tank 11 together with the seaweed, or they may be injected into the fermentation tank 11 separately from the seaweed. As a result, the seaweed ferments in the fermentation tank 11 (step S106).

[0041] After a predetermined period (for example, 14 days) has elapsed since the start of fermentation in the fermentation tank 11, the fermented liquid produced from seaweed is removed from the fermentation tank 11 (step S107). The residue is removed from the removed fermented liquid by the second centrifuge 7 (step S108). This separation may be by gravity separation or by pressure separation. The residue separated from the fermented liquid is stored in the residue tank 12. The residue stored in the residue tank 12 may be processed and used as fuel for the floating equipment 1, or it may be incinerated on board without processing, or it may be transported offboard as a raw material for fertilizer, etc.

[0042] The fermented liquid from which the residue has been removed is sent to the distillation column 8 (step S109). The fermented liquid is distilled in the distillation column 8 to produce ethanol (step S110). The concentration of the ethanol is at least a concentration that can be used as fuel for ships, etc. (for example, 95%). In addition, to increase the purity of the ethanol, treatment such as dehydration may be performed to produce ethanol with a concentration of approximately 99.5% or higher (anhydrous ethanol).

[0043] The ethanol produced in the distillation column 8 is stored in the ethanol tank 13 (step S111). In this way, bioethanol is produced from the raw material seaweed.

[0044] The ethanol stored in the ethanol tank 13 is shipped as a product (step S112). For example, the ethanol is transferred to an ethanol tanker or a land-based facility. The method of transferring the ethanol overboard may be any. For example, a pipeline may be connected to the ethanol tank 13 so that the ethanol flows through the pipeline. Alternatively, the ethanol tank 13 may be made detachable from the hull 10, and the ethanol may be transported overboard along with the ethanol tank 13.

[0045] Referring to Figure 4, a method for controlling the attitude of the floating watercraft 1 will be described. For example, attitude control is performed by a loading computer. Alternatively, attitude control may be automatically controlled by the IAS based on the calculation results of the loading computer, or it may be manually remotely controlled using the IAS.

[0046] First, we will explain how to select the fermentation tank 11 into which the seaweed is injected before fermentation. This selection of the fermentation tank 11 may be done by any computer or manually.

[0047] If there is one empty fermentation tank 11, seaweed is injected into that empty fermentation tank 11. If there are multiple empty fermentation tanks 11, one of the multiple fermentation tanks 11 is selected. If there are no empty fermentation tanks 11, the injection of seaweed is stopped, or if there is remaining capacity in the most recently injected fermentation tank 11, it is injected into that fermentation tank 11.

[0048] For example, when selecting one of several fermentation tanks 11, the fermentation tank 11 is determined in a predetermined order so that the orientation of the floating watercraft 1 is ideally maintained. Alternatively, a computer calculates and determines which fermentation tank 11 is best to inject seaweed into in order to maintain the orientation of the floating watercraft 1. Note that the selection of the fermentation tank 11 to which seaweed is injected can be made in any way and may be determined regardless of the orientation of the floating watercraft 1.

[0049] Here, the yield of seaweed is not constant because it is affected by the natural environment. Therefore, the amount of contents stored in each fermentation tank 11 is usually different. As a result, the weight of the contents of each fermentation tank 11 may cause the floating structure 1 to tilt. Therefore, the attitude of the floating structure 1 is controlled as follows.

[0050] The computer constantly calculates and monitors the trim, which indicates the longitudinal (longitudinal) tilt of the hull, the heel, which indicates the lateral tilt of the hull, and the longitudinal strength (step S201).

[0051] If at least one of the calculated values ​​for trim, heel, and longitudinal strength exceeds a threshold, the computer issues an alarm indicating that an abnormality in the attitude of the floating watercraft 1 has been detected (step S202). The alarm may be accompanied by at least one of a display or sound.

[0052] If an alarm is issued, the computer selects two fermentation tanks 11 to correct the posture anomaly (step S203). Depending on the type of anomaly, such as trim, heel, or longitudinal strength, the computer selects two fermentation tanks 11 to transfer the contents.

[0053] If an empty fermentation tank 11 is available, this fermentation tank 11 is selected as the destination fermentation tank 11 with the highest priority. If no empty fermentation tank 11 is available, the two fermentation tanks 11 to be selected are given priority based on the number of days elapsed since fermentation (i.e., the date on which the seaweed was injected).

[0054] If the fermentation time elapsed in the two fermentation tanks 11 is different, the fermentation time elapsed in the destination fermentation tank 11 needs to be updated. For example, if the fermentation time elapsed in the destination fermentation tank 11 is longer than that of the source fermentation tank 11, the fermentation time elapsed in the destination fermentation tank 11 should be updated to match that of the source fermentation tank 11. Otherwise, the fermentation time elapsed in the destination fermentation tank 11 does not need to be changed.

[0055] Once the computer determines which two fermentation tanks 11 will transfer the contents, it calculates the amount of contents to be transferred between the two fermentation tanks 11 in order to resolve any abnormalities that may cause an alarm (step S204).

[0056] Here, the capacity of the destination fermentation tank 11, one of the two fermentation tanks 11, must have enough empty space to accept the contents. For example, if the two fermentation tanks 11 have the same capacity, and the source fermentation tank 11 is filled to 100% of its capacity, and the destination fermentation tank 11 is filled to 75% of its capacity, then a maximum of 25% of the contents can be transferred. Therefore, if the abnormality is not resolved by transferring less than 25% of the contents, it is necessary to find the other two fermentation tanks 11. Considering that the fermentation tanks 11 are also used for attitude control, it is desirable that the capacity of the fermentation tanks 11 have a capacity margin of about 10% compared to the normal amount of seaweed to be fermented in one day.

[0057] The computer calculates the amount of contents to be transferred and then transfers the calculated amount of contents from the source fermentation tank 11 to the destination fermentation tank 11 (step S205). By opening the emergency valve 26 provided in the emergency piping 23, it becomes possible to transfer contents between the two fermentation tanks 11.

[0058] If there is no impediment to the transfer of contents between the two fermentation tanks 11, at least one of the intermediate valves 24, 25 of the seaweed piping 21 or the fermentation liquid piping 22 may be closed. This allows the seaweed piping 21 or the fermentation liquid piping 22 on the stern AP side of the closed intermediate valves 24, 25 to perform its original function of supplying seaweed or withdrawing fermentation liquid at the same time as transferring contents between the two fermentation tanks 11.

[0059] The computer checks whether the alarm has stopped (i.e., whether the abnormality has been resolved) after the contents have been transferred between the two fermentation tanks 11 (step S206). If the alarm has stopped, the computer terminates the attitude control to resolve the attitude abnormality (Yes in step S206). If the alarm has not stopped, the computer selects the two fermentation tanks 11 again to resolve the attitude abnormality (No in step S206, step S203).

[0060] Furthermore, it is desirable to minimize the number of times the contents are transferred between the two fermentation tanks 11. Therefore, the computer may predict the orientation of the floating structure 1 after the contents have been transferred and select the two fermentation tanks 11 so that the abnormality is resolved with the minimum number of contents transfers.

[0061] For example, if two fermentation tanks 11 are selected to eliminate a heel anomaly, even if the heel anomaly is resolved after the contents are transferred, anomalies in trim or longitudinal strength may still occur. In this case, it is desirable to select two fermentation tanks 11 so that no anomalies of any kind occur after the contents are transferred. Furthermore, it is possible that all types of anomalies cannot be prevented without transferring the contents between three or more fermentation tanks 11. In this case, the number of contents transfers can be minimized by simulating the transfer of contents between multiple fermentation tanks 11 in advance using a computer.

[0062] In this description, we have explained a configuration in which the fermentation tank 11 functions as a ballast tank for attitude control without providing a dedicated ballast tank for attitude control. However, a separate ballast tank may be provided in addition to the fermentation tank 11. In this case as well, the fermentation tank 11 may function as a ballast tank.

[0063] Furthermore, if dedicated ballast tanks are to be installed, it is desirable to minimize their number. For example, attitude control can be achieved with 2 to 4 ballast tanks each on the port and starboard sides. Therefore, when modifying VLCCs, etc., the volumetric efficiency of the floating equipment 1 can be increased by leaving only the minimum necessary ballast tanks and using the remaining ballast tanks as fermentation tanks 11, etc.

[0064] Figure 5 is a diagram showing the configuration of the carbon dioxide fixation system 40 that fixes carbon dioxide in the sea in the floating watercraft 1 according to this embodiment.

[0065] The carbon dioxide fixation system 40 includes multiple air vents 41, a pressure control valve 42, a compressor 43, and carbon dioxide piping 44.

[0066] Each air vent 41 is provided in the fermentation tank 11. When the internal pressure of the fermentation tank 11 exceeds a predetermined value set for the air vent 41, the air vent 41 is opened. When the air vent 41 is opened, carbon dioxide inside the fermentation tank 11 is released into the carbon dioxide piping 44. Once carbon dioxide has been released from the fermentation tank 11 and the internal pressure of the fermentation tank 11 falls below the predetermined value set for the air vent 41, the air vent 41 is closed. The carbon dioxide released from each air vent 41 is sent to the compressor 43 via the carbon dioxide piping 44.

[0067] Inside the fermentation tank 11, carbon dioxide is generated as the raw materials ferment. The air vent 41 prevents the internal pressure of the fermentation tank 11 from becoming excessive by releasing the carbon dioxide generated inside the fermentation tank 11 to the outside. Therefore, by providing the air vent 41, the internal pressure of the fermentation tank 11 is controlled.

[0068] The pressure control valve 42 is installed in the carbon dioxide piping 44 that connects each air vent 41 to the compressor 43. When the internal pressure of the carbon dioxide piping 44 exceeds a set predetermined value, the pressure control valve 42 sends the carbon dioxide released from each fermentation tank 11 to the compressor 43. The carbon dioxide released from each fermentation tank 11 may be stored in a tank or the like before being sent to the compressor 43. The pressure control valve 42 may also be installed to control the internal pressure of the tank or the like where the carbon dioxide is stored.

[0069] The compressor 43 compresses the carbon dioxide released from each fermentation tank 11 and releases it into the sea (water). The carbon dioxide compressed by the compressor 43 is released through a pipeline with an outlet in the sea. As a result, the carbon dioxide generated in each fermentation tank 11 is fixed in the sea, and carbon dioxide emissions are suppressed.

[0070] According to this embodiment, bioethanol can be efficiently produced using aquatic plants as raw materials.

[0071] Furthermore, by using the fermentation tank 11 for fermenting plants as a ballast tank, there is no need to provide a separate ballast tank for attitude control on the floating watercraft 1. Therefore, the space on the floating watercraft 1 can be utilized more effectively compared to the case where a separate ballast tank for attitude control is provided.

[0072] Furthermore, by installing the carbon dioxide fixation system 40, the carbon dioxide generated in the fermentation tank 11 can be fixed in the natural water environment. This reduces the amount of carbon dioxide emitted by the floating water facility 1. In addition, if seaweed, which is the raw material, is being cultivated near the floating water facility 1, the growth of the cultivated seaweed can be promoted. It should be noted that the production of bioethanol in the floating water facility 1 is not affected even if the carbon dioxide fixation system 40 is not installed.

[0073] The present invention is not limited to the embodiments described above, and components may be deleted, added, or modified. Furthermore, new embodiments may be created by combining or replacing components in multiple embodiments. Even if such embodiments differ directly from the embodiments described above, those that share a similar purpose to the present invention are described as embodiments of the present invention, and their descriptions are omitted. [Explanation of Symbols]

[0074] 1...Floating structure, 2...Harvesting equipment, 3...Washing section, 4...Pre-crushing storage section, 5...Crusher, 6...First centrifugal separator, 7...Second centrifugal separator, 8...Distillation column, 10...Hull, 11...Fermentation tank, 12...Residue tank, 13...Ethanol tank.

Claims

1. Multiple fermentation tanks for storing crushed aquatic plants for fermentation, A control unit that performs attitude control by selecting two fermentation tanks from the plurality of fermentation tanks and transferring the contents between the two selected fermentation tanks. A floating structure equipped with [a specific feature].

2. The control unit selects an empty fermentation tank as one of the two fermentation tanks used for attitude control. The floating watercraft equipment according to claim 1.

3. The control unit selects at least one of the two fermentation tanks used for attitude control based on the number of days elapsed since the plant contents began to ferment. The floating watercraft equipment according to claim 1.

4. The control unit selects two fermentation tanks, each with a different number of days elapsed during fermentation, to be used for attitude control. The floating watercraft equipment according to claim 3.

5. The control unit prioritizes selecting two fermentation tanks with similar fermentation durations as the two fermentation tanks used for attitude control. The floating watercraft equipment according to claim 3.

6. The control unit calculates the amount of contents to be transferred between the two selected fermentation tanks in order to correct any abnormalities in posture. The floating watercraft equipment according to claim 1.

7. It was constructed in the shape of a ship. A floating watercraft according to claim 1, characterized by the following:

8. A method for controlling the attitude of a floating watercraft equipped with multiple fermentation tanks for storing crushed aquatic plants for fermentation, Select two fermentation tanks from the aforementioned multiple fermentation tanks, The attitude is controlled by transferring the contents between the two selected fermentation tanks. A method for controlling the attitude of a floating watercraft, including the equipment mentioned above.

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