Seaweed resource recovery system

Abstract

To provide a seaweed recycling system which can effectively utilize waste water.SOLUTION: A seaweed recycling system includes: an alginic acid production apparatus for performing treatment of cleaning seaweed, treatment for extracting an aqueous solution containing an alginic acid component from the cleaned seaweed, treatment for diluting the extracted aqueous solution, treatment for separating the diluted aqueous solution from the seaweed, treatment for solidifying and precipitating an alginic acid from the aqueous solution separated from the seaweed, and treatment for dehydrating the precipitated alginic acid; a water purifier for subjecting waste water generated by dehydration treatment to purification treatment; a fresh water production apparatus for producing fresh water from at least any one of sea water and waste water purified by the water purifier; a hydrogen production apparatus for producing hydrogen from at least any one of sea water, fresh water produced by the fresh water production apparatus, and waste water purified by the water purifier; and a control device for supplying the waste water purified by the water purifier to any one of the fresh water production apparatus, the hydrogen production apparatus and the alginic acid production apparatus.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a seaweed resource production system. [Background technology]

[0002] In recent years, there has been a demand for effective use of wastewater generated during resource recovery processes using seaweed at marine plants. For example, Patent Document 1 discloses a system that utilizes natural phenomena to grow seaweed, captures carbon dioxide from the air, and uses the seaweed to produce, separate, and recover methanol, hydrogen, and carbon dioxide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-35967 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 only discloses the production of methanol, hydrogen, and carbon dioxide by utilizing seaweed, and does not disclose a method for utilizing wastewater generated by the processing of seaweed into a resource. In other words, Patent Document 1 has a problem in that it is not possible to effectively utilize wastewater generated by the processing of seaweed into a resource.

[0005] The present disclosure has been made in consideration of the above background, and aims to provide a seaweed resource recovery system that can effectively utilize wastewater generated during the seaweed resource recovery process. [Means for solving the problem]

[0006] The seaweed resource recovery system according to the present disclosure is a seaweed resource recovery system for recovering seaweed from the sea, and includes an alginic acid production apparatus which performs the following processes: washing seaweed obtained from the sea, extracting an aqueous solution containing an alginic acid component from the washed seaweed, diluting the extracted aqueous solution, separating the diluted aqueous solution from the seaweed, coagulating and precipitating alginic acid from the aqueous solution separated from the seaweed, and dehydrating the precipitated alginic acid; a water purification apparatus which performs a purification process on wastewater generated by the dehydration process in the alginic acid production apparatus; The system includes a freshwater producing device that produces freshwater from at least one of the wastewater purified by the water purification device, which is used at least for the cleaning process and dilution process in the alginic acid producing device, a hydrogen producing device that produces hydrogen to be used in a fuel cell from at least one of seawater, the freshwater produced by the freshwater producing device, and the wastewater purified by the water purification device, and a control device that supplies the wastewater purified by the water purification device to at least one of the freshwater producing device, the hydrogen producing device, and the alginic acid producing device used as dilution water for the dilution process. This seaweed resource production system purifies wastewater generated in the process of producing alginic acid from seaweed and supplies it to at least one of the freshwater producing device, the hydrogen producing device, and the alginic acid producing device, thereby making effective use of the wastewater. In other words, this seaweed resource production system can make effective use of wastewater generated by the seaweed resource production process. Effect of the Invention

[0007] The present disclosure makes it possible to provide a seaweed resource recovery system that can effectively utilize wastewater generated during the seaweed resource recovery process. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration example of a seaweed resource conversion system according to a first embodiment. [Diagram 2] 2 is a flowchart showing a method for producing alginic acid by the alginic acid production apparatus provided in the seaweed resource recovery system shown in FIG. 1. [Diagram 3] 2 is a flowchart showing a part of the operation of the seaweed resource production system shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. In addition, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0010] <Embodiment 1> FIG. 1 is a block diagram showing an example of the configuration of a seaweed resource recovery system 1 according to a first embodiment. The seaweed resource recovery system 1 is applied to marine plants constructed on the sea where it is difficult to freely bring in resources from land. Here, the seaweed resource recovery system 1 can effectively utilize wastewater generated in the process of producing alginic acid from seaweed by purifying the wastewater and supplying it to at least one of a freshwater production device, a hydrogen production device, and an alginic acid production device. In other words, the seaweed resource recovery system 1 can effectively utilize wastewater generated by the seaweed resource recovery process. A specific description will be given below.

[0011] 1, the seaweed resource recovery system 1 includes an alginic acid production apparatus 11, a water purification apparatus 12, a fresh water production apparatus 13, a hydrogen production apparatus 14, a group of power generation apparatuses 15, and a control device 16. The control device 16 is configured to be able to communicate with the alginic acid production apparatus 11, the water purification apparatus 12, the fresh water production apparatus 13, the hydrogen production apparatus 14, and the group of power generation apparatuses 15 via a wired or wireless network (not shown).

[0012] The alginic acid production apparatus 11 is one of the apparatuses for treating seaweed as a resource, and produces alginic acid from seaweed. Hereinafter, the method for producing alginic acid using the alginic acid production apparatus 11 will be briefly described with reference to Fig. 2. Fig. 2 is a flow chart showing the method for producing alginic acid using the alginic acid production apparatus 11.

[0013] The alginic acid production apparatus 11 produces alginic acid from seaweed by carrying out washing, extraction, dilution, separation, precipitation, and dehydration processes.

[0014] First, the alginic acid producing apparatus 11 washes seaweed obtained from the sea in a washing process (step S101).

[0015] Thereafter, the alginic acid production apparatus 11 extracts an aqueous solution containing an alginic acid component from the washed seaweed in an extraction process (step S102). Specifically, the alginic acid contained in the seaweed is combined with polyvalent cations such as Ca to form insoluble salts. Therefore, the alginic acid production apparatus 11 performs ion exchange between polyvalent cations such as Ca and Na to form water-soluble sodium alginate, thereby extracting an aqueous solution containing an alginic acid component.

[0016] Thereafter, the alginic acid production apparatus 11 adds a large amount of water to the extracted aqueous solution (sodium alginate aqueous solution) in a dilution process (step S103). As a result, the viscosity of the sodium alginate aqueous solution is weakened by dilution, making it easier to separate from the seaweed.

[0017] Thereafter, the alginic acid producing apparatus 11 separates the diluted aqueous solution (aqueous sodium alginate solution) from the seaweed in a separation process (step S104).

[0018] Thereafter, the alginic acid producing apparatus 11 coagulates and precipitates alginic acid from the aqueous solution separated from the seaweed in a precipitation process (step S105). Specifically, the alginic acid producing apparatus 11 adds an acid to the aqueous alginic acid solution to coagulate and precipitate insoluble alginic acid.

[0019] Thereafter, the alginic acid producing apparatus 11 dehydrates the precipitated alginic acid in a dehydration process (step S106). In this manner, the alginic acid producing apparatus 11 produces alginic acid from seaweed.

[0020] The water purification device 12 produces purified water by performing a purification process on wastewater generated by a dehydration process, which is one of the processes performed by the alginic acid production apparatus 11. Here, a portion of the purified water (purified wastewater) produced by the water purification device 12 is used as dilution water for a dilution process in the alginic acid production apparatus 11. Note that a portion of the purified water may also be used for a cleaning process in the alginic acid production apparatus 11. This allows the seaweed resource recovery system 1 to effectively utilize wastewater generated in the process of producing alginic acid from seaweed.

[0021] The freshwater producing apparatus 13 produces freshwater from at least one of seawater and purified water produced by the water purification apparatus 12. Here, the salt concentration of the purified water produced by the water purification apparatus 12 is lower than that of seawater and closer to that of freshwater. Therefore, the freshwater producing apparatus 13 can desalinate the purified water more easily than seawater. The freshwater produced by the freshwater producing apparatus 13 is used for cleaning and dilution processes of the alginic acid producing apparatus 11, and is used for producing hydrogen by the hydrogen producing apparatus 14 described later.

[0022] The hydrogen production device 14 produces hydrogen by electrolyzing at least one of seawater, the fresh water produced by the fresh water production device 13, and the purified water produced by the water purification device 12. The hydrogen produced by the hydrogen production device 14 is used to generate electricity in a fuel cell 153, which will be described later.

[0023] The power generation device group 15 includes a wind power generation device 151, a solar power generation device 152, and a fuel cell 153. The power generation device group 15 may include at least one of the wind power generation device 151, the solar power generation device 152, and the fuel cell 153. Electricity generated in the power generation device group 15 is used to operate the marine plant to which the seaweed resource recovery system 1 is applied. Water generated by the power generation of the fuel cell 153 may be used for cleaning and dilution processes of the alginic acid production apparatus 11.

[0024] The control device 16 performs overall control of the seaweed resource recovery system 1. Here, the control device 16 controls the supply of purified water generated by the water purification device 12 to the fresh water production device 13, the hydrogen production device 14, and the alginic acid production device 11. More specifically, the control device 16 controls the supply ratio of purified water generated by the water purification device 12 to the fresh water production device 13, the hydrogen production device 14, and the alginic acid production device 11 depending on, for example, the remaining amount of fresh water, the remaining amount of hydrogen, and the operating status of the alginic acid production device 11. This allows the seaweed resource recovery system 1 to effectively utilize wastewater generated in the process of producing alginic acid from seaweed.

[0025] For example, when the remaining amount of fresh water is less than a predetermined remaining amount, the control device 16 increases the supply ratio of purified water, which is easier to desalinate than seawater, to the fresh water producing device 13.

[0026] Also, for example, when the remaining amount of fresh water is less than a predetermined remaining amount and the remaining amount of hydrogen is less than a predetermined remaining amount, the control device 16 increases the supply ratio of purified water to the hydrogen production device 14. This achieves lower costs and higher efficiency than producing fresh water and supplying it to the hydrogen production device 14.

[0027] Furthermore, for example, when the alginic acid production apparatus 11 is operating at full capacity, a large amount of dilution water is required for the dilution process of the alginic acid production apparatus 11, so the control device 16 increases the supply ratio of purified water to the alginic acid production apparatus 11.

[0028] The control device 16 may control the supply ratio of purified water generated by the water purification device 12 to the fresh water production device 13, the hydrogen production device 14, and the alginic acid production device 11 according to the remaining amount of energy used to operate the alginic acid production device 11 (the amount of power generated by the power generation device group 15). In this case, for example, the control device 16 increases the supply ratio of purified water to the hydrogen production device 14 as the remaining amount of energy decreases, decreases the supply ratio of purified water to the hydrogen production device 14 as the remaining amount of energy increases, and increases the supply ratio of purified water to the alginic acid production device 11, which is predicted to be operating at full capacity.

[0029] The above-mentioned method of controlling the supply ratio of purified water by the control device 16 is merely one example, and may be changed as appropriate.

[0030] (Operation of seaweed resource recovery system 1) Next, a part of the operation of the seaweed resource conversion system 1 will be described with reference to Fig. 3. Fig. 3 is a flow chart showing a part of the operation of the seaweed resource conversion system 1.

[0031] First, the seaweed resource recovery system 1 produces alginic acid from seaweed using the alginic acid production apparatus 11 (step S201). During the production of alginic acid, the seaweed resource recovery system 1 performs a purification process on wastewater generated in the dehydration process, which is one of the processes performed by the alginic acid production apparatus 11, using the water purification device 12 (step S202).

[0032] Here, the seaweed resource recovery system 1 controls the supply of purified water generated by the water purification device 12 to the fresh water production device 13, the hydrogen production device 14, and the alginic acid production device 11. More specifically, the seaweed resource recovery system 1 controls the supply ratio of purified water generated by the water purification device 12 to the fresh water production device 13, the hydrogen production device 14, and the alginic acid production device 11 depending on, for example, the remaining amount of fresh water, the remaining amount of hydrogen, and the operating status of the alginic acid production device 11 (step S203). This allows the seaweed resource recovery system 1 to effectively utilize wastewater generated in the process of producing alginic acid from seaweed.

[0033] The seaweed resource recovery system 1 supplies the purified water produced by the water purification device 12 at a specified supply ratio to the alginic acid production device 11 (step S204). The purified water supplied to the alginic acid production device 11 is used, for example, as dilution water for a dilution process, which is one of the processes of the alginic acid production device 11.

[0034] Thereafter, the seaweed resource recovery system 1 uses the freshwater production device 13 to produce freshwater from seawater and purified water produced by the water purification device 12, which is supplied at a specified supply ratio (step S205). Here, the salt concentration of the purified water produced by the water purification device 12 is lower than seawater and closer to freshwater. Therefore, the freshwater production device 13 can desalinate the purified water more easily than seawater. Then, the seaweed resource recovery system 1 supplies a portion of the freshwater produced by the freshwater production device 13 to the alginic acid production device 11 (step S206). The freshwater supplied to the alginic acid production device 11 is used for cleaning and dilution processes of the alginic acid production device 11.

[0035] Thereafter, the seaweed resource recovery system 1 produces hydrogen by electrolyzing seawater, fresh water produced by the fresh water production device 13, and purified water produced by the water purification device 12, which are supplied at a specified supply ratio, using the hydrogen production device 14 (step S207). The seaweed resource recovery system 1 then supplies the hydrogen produced by the hydrogen production device 14 to the fuel cell 153 (step S208). The hydrogen produced by the hydrogen production device 14 is used to generate electricity in the fuel cell 153.

[0036] In this way, the seaweed resource recovery system 1 according to this embodiment can effectively utilize the wastewater generated in the process of producing alginic acid from seaweed by purifying the wastewater and supplying it to at least one of the freshwater production device 13, the hydrogen production device 14, and the alginic acid production device 11. In other words, the seaweed resource recovery system 1 according to this embodiment can effectively utilize the wastewater generated in the process of producing seaweed as a resource.

[0037] The present invention is not limited to the above-mentioned embodiment, and can be modified as appropriate without departing from the spirit of the invention. The present invention promotes the use of blue carbon (seaweed) and contributes to the Sustainable Development Goals (SDGs) and carbon neutrality.

[0038] Furthermore, the present disclosure can be realized by causing a CPU (Central Processing Unit) to execute a computer program, partly or in whole, of the processing of the seaweed resource conversion system 1.

[0039] The above-mentioned program includes a set of instructions (or software code) for making the computer perform one or more functions described in the embodiment when the program is loaded into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the tangible storage medium includes a random-access memory (RAM), a read-only memory (ROM), a flash memory, a solid-state drive (SSD) or other memory technology, a CD-ROM, a digital versatile disc (DVD), a Blu-ray® disk or other optical disk storage, a magnetic cassette, a magnetic tape, a magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or the communication medium includes an electrical, optical, acoustic, or other form of propagating signal.

[0040] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes.

[0041] (Appendix 1) A seaweed resource recovery method using a seaweed resource recovery system that performs seaweed resource recovery processing, A dehydration process is carried out using an alginic acid production apparatus which performs the following processes: washing seaweed obtained from the sea; extracting an aqueous solution containing an alginic acid component from the washed seaweed; diluting the extracted aqueous solution; separating the diluted aqueous solution from the seaweed; coagulating and precipitating alginic acid from the aqueous solution separated from the seaweed; and dehydrating the precipitated alginic acid. A water purification device is used to purify the wastewater generated by the dehydration process; Using a freshwater producing apparatus, freshwater is produced from at least one of seawater and the wastewater purified by the water purification apparatus, and the freshwater is used at least for the cleaning process and the dilution process in the alginic acid producing apparatus; Using a hydrogen production device, hydrogen to be used in a fuel cell is produced from at least one of seawater, fresh water produced by the fresh water production device, and the wastewater purified by the water purification device; Using a control device, the wastewater purified by the water purification device is supplied to at least one of the fresh water production device, the hydrogen production device, and the alginic acid production device used as dilution water for the dilution process; Seaweed resource recycling method.

[0042] (Appendix 2) A control program for causing a computer to execute a process for recycling seaweed, A step of performing a dehydration process using an alginic acid production apparatus which performs the following processes: washing seaweed obtained from the sea; extracting an aqueous solution containing an alginic acid component from the washed seaweed; diluting the extracted aqueous solution; separating the diluted aqueous solution from the seaweed; coagulating and precipitating alginic acid from the aqueous solution separated from the seaweed; and dehydrating the precipitated alginic acid. A step of performing a purification process on the wastewater generated by the dehydration process using a water purification device; A step of producing fresh water to be used at least for the cleaning process and the dilution process in the alginic acid production apparatus from at least one of seawater and the wastewater purified by the water purification apparatus using a fresh water production apparatus; producing hydrogen for use in a fuel cell from at least one of seawater, fresh water produced by the fresh water production device, and the waste water purified by the water purification device, using a hydrogen production device; A step of supplying the wastewater purified by the water purification device to at least one of the fresh water production device, the hydrogen production device, and the alginic acid production device, which is used as dilution water for the dilution process, using a control device; A control program comprising: [Explanation of symbols]

[0043] 1. Seaweed resource recovery system 11 Alginic acid manufacturing equipment 12 Water purification equipment 13 Freshwater production equipment 14 Hydrogen production equipment 15 Power generating equipment group 16 Control device 151 Wind power generation equipment 152 Solar power generation equipment 153 Fuel Cell

Claims

1. A seaweed resource recycling system for processing seaweed resources, an alginic acid production apparatus which performs the steps of washing seaweed obtained from the sea, extracting an aqueous solution containing an alginic acid component from the washed seaweed, diluting the extracted aqueous solution, separating the diluted aqueous solution from the seaweed, coagulating and precipitating alginic acid from the aqueous solution separated from the seaweed, and dehydrating the precipitated alginic acid; A water purification device that purifies wastewater generated by the dehydration treatment in the alginic acid production device; A freshwater producing apparatus for producing freshwater to be used at least for the cleaning process and dilution process in the alginic acid producing apparatus from at least one of seawater and the wastewater purified by the water purification apparatus; a hydrogen production device that produces hydrogen to be used in a fuel cell from at least one of seawater, the fresh water produced by the fresh water production device, and the wastewater purified by the water purification device; A control device that supplies the wastewater purified by the water purification device to at least one of the fresh water production device, the hydrogen production device, and the alginic acid production device, which is used as dilution water for dilution treatment; A seaweed resource recovery system equipped with the above.

2. The control device controls the supply ratio of the wastewater purified by the water purification device to the freshwater production device, the hydrogen production device, and the alginic acid production device according to the remaining amount of freshwater, the remaining amount of hydrogen, and the operating status of the alginic acid production device. The seaweed resource production system according to claim 1.

3. The control device controls the supply ratio of the wastewater purified by the water purification device to the fresh water production device, the hydrogen production device, and the alginic acid production device according to the remaining amount of energy used to operate the alginic acid production device. The seaweed resource production system according to claim 1.

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