JP2024071132A - Seaweed resource recovery system - Google Patents

Abstract

[Problem] To provide a seaweed resource recovery system capable of effectively utilizing wastewater generated in the process of recovering seaweed as a resource. [Solution] The seaweed resource recovery system according to the present disclosure is a seaweed resource recovery system that recovers seaweed as a resource, and includes at least an alginic acid production device that performs the processes 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 performs a purification process on wastewater generated by the dehydration process in the alginic acid production device, and a freshwater production device that produces freshwater from seawater to be used at least in the washing process and dilution process in the alginic acid production device, and the freshwater production device further produces freshwater from the wastewater purified by the water purification device. [Selected Figure] Figure 1

Description

This disclosure relates to a seaweed resource production system.

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.

JP 2005-35967 A

However, Patent Document 1 only discloses the production of methanol, hydrogen, and carbon dioxide using seaweed, and does not disclose a method for utilizing the wastewater generated during the seaweed resource processing. In other words, Patent Document 1 has the problem of being unable to effectively utilize the wastewater generated during the seaweed resource processing.

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.

The seaweed resource recovery system according to the present disclosure is a seaweed resource recovery system that performs a process of recovering seaweed, and includes at least an alginic acid production device that 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 that performs a purification process on wastewater generated by the dehydration process in the alginic acid production device; and a freshwater production device that produces freshwater from seawater to be used at least in the washing process and dilution process in the alginic acid production device, and the freshwater production device further produces the freshwater from the wastewater purified by the water purification device. This seaweed resource recovery system can effectively utilize the wastewater by purifying the wastewater generated in the process of producing alginic acid from seaweed and using it as dilution water in the dilution process, which is one of the processes for producing alginic acid. In addition, this seaweed resource recovery system can use a freshwater production device to produce freshwater more easily than seawater from wastewater with a low salinity concentration that has been purified by a water purification device. In other words, this seaweed resource recovery system can effectively utilize the wastewater generated by the seaweed resource recovery process.

This disclosure provides a seaweed resource recovery system that can effectively utilize wastewater generated during the seaweed resource recovery process.

1 is a block diagram showing a configuration example of a seaweed resource conversion system according to a first embodiment. FIG. 2 is a flowchart showing a method for producing alginic acid using the alginic acid production apparatus provided in the seaweed resource recovery system shown in FIG. 1. 2 is a flowchart showing a part of the operation of the seaweed resource production system shown in FIG. 1 .

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. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and duplicate explanations have been omitted as necessary.

<First embodiment>
FIG. 1 is a block diagram showing a configuration example of a seaweed resource recovery system 1 according to the 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 using it as dilution water in a dilution process, which is one of the processes for producing alginic acid. In addition, the seaweed resource recovery system 1 can use a freshwater production device to produce freshwater more easily than seawater from wastewater with a low salinity concentration purified by a water purification device. In other words, the seaweed resource recovery system 1 can effectively utilize wastewater generated by the process of producing resources from seaweed. A specific description will be given below.

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

The alginic acid production apparatus 11 is one of the devices that processes seaweed into a resource, and produces alginic acid from seaweed. Below, 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.

The alginic acid production device 11 produces alginic acid from seaweed by performing cleaning, extraction, dilution, separation, precipitation, and dehydration processes.

First, the alginic acid production apparatus 11 washes the seaweed obtained from the ocean in a cleaning process (step S101).

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

Then, in a dilution process, the alginic acid production apparatus 11 dilutes the extracted aqueous solution (sodium alginate aqueous solution) by adding a large amount of water (step S103). As a result, the sodium alginate aqueous solution becomes less viscous by being diluted, making it easier to separate from the seaweed.

Then, the alginic acid production apparatus 11 separates the diluted aqueous solution (sodium alginate aqueous solution) from the seaweed in a separation process (step S104).

Then, in a precipitation process, the alginic acid production apparatus 11 coagulates and precipitates alginic acid from the aqueous solution separated from the seaweed (step S105). Specifically, the alginic acid production apparatus 11 adds acid to the aqueous alginic acid solution to coagulate and precipitate insoluble alginic acid.

Then, the alginic acid production apparatus 11 dehydrates the precipitated alginic acid in a dehydration process (step S106). In this way, the alginic acid production apparatus 11 produces alginic acid from seaweed.

The water purification device 12 produces purified water by performing a purification process on wastewater generated by the dehydration process, which is one of the processes performed by the alginic acid production device 11. Here, a portion of the purified water (purified wastewater) produced by the water purification device 12 is used as dilution water for the dilution process in the alginic acid production device 11. Note that a portion of the purified water may also be used for the cleaning process in 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.

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

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

The power generation group 15 includes a wind power generation device 151, a solar power generation device 152, and a fuel cell 153. The power generation 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. The electricity generated in the power generation group 15 is used to operate the marine plant to which the seaweed resource recovery system 1 is applied. The water generated by the power generation of the fuel cell 153 may be used for cleaning and dilution processes of the alginic acid production device 11.

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.

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

For example, when the remaining amount of fresh water is less than a predetermined amount and the remaining amount of hydrogen is less than a predetermined 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.

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 ratio of purified water supplied to the alginic acid production apparatus 11.

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 operate at full capacity.

The above-described method of controlling the purified water supply ratio by the control device 16 is merely one example and may be modified as appropriate.

(Operation of seaweed resource recovery system 1)
Next, a part of the operation of the seaweed resource production 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 production system 1.

First, the seaweed resource recovery system 1 produces alginic acid from seaweed using the alginic acid production device 11 (step S201). During the production of alginic acid, the seaweed resource recovery system 1 uses the water purification device 12 to perform a purification process on wastewater generated in the dehydration process, which is one of the processes of the alginic acid production device 11 (step S202). Then, the seaweed resource recovery system 1 supplies a portion of the purified water produced by the water purification device 12 to the alginic acid production device 11 (step S203). The purified water supplied to the alginic acid production device 11 is used, for example, as dilution water for the dilution process, which is one of the processes of the alginic acid production device 11.

Then, the seaweed resource recovery system 1 uses the freshwater production device 13 to produce freshwater from at least one of seawater and purified water produced by the water purification device 12 (step S204). Here, the salt concentration of the purified water produced by the water purification device 12 is lower than that of seawater and closer to that of 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 S205). The freshwater supplied to the alginic acid production device 11 is used for cleaning and dilution processes of the alginic acid production device 11.

Then, the seaweed resource production system 1 uses the hydrogen production device 14 to produce 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 (step S206). The seaweed resource production system 1 then supplies the hydrogen produced by the hydrogen production device 14 to the fuel cell 153 (step S207). The hydrogen produced by the hydrogen production device 14 is used to generate electricity in the fuel cell 153.

In this way, the seaweed resource recovery system 1 according to this embodiment can effectively utilize wastewater generated in the process of producing alginic acid from seaweed by purifying the wastewater and using it as dilution water in the dilution process, which is one of the processes for producing alginic acid. Furthermore, the seaweed resource recovery system 1 according to this embodiment can use the freshwater production device 13 to produce freshwater more easily than seawater from wastewater with a low salinity concentration purified by the water purification device 12. In other words, the seaweed resource recovery system 1 according to this embodiment can effectively utilize wastewater generated in the process of converting seaweed into a resource.

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.

In addition, this disclosure can be realized by having a CPU (Central Processing Unit) execute a computer program to perform some or all of the processing of the seaweed resource processing system 1.

The above-mentioned program includes a set of instructions (or software code) that, when loaded into a computer, causes the computer to perform one or more functions described in the embodiments. The program may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include RAM (Random-Access Memory), ROM (Read-Only Memory), flash memory, SSD (Solid-State Drive) or other memory technology, CD-ROM, DVD (Digital Versatile Disc), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a temporary computer-readable medium or communication medium. By way of example and not limitation, the temporary computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagating signals.

A part or all of the above embodiments may be described as follows, but is not limited to the following:

(Appendix 1)
A seaweed resource recovery method using a seaweed resource recovery system that performs a seaweed resource recovery process,
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 seawater to be used at least for the cleaning process and dilution process in the alginic acid producing apparatus;
Using the fresh water producing apparatus, the fresh water is further produced from the wastewater purified by the water purification apparatus.
Methods for turning seaweed into resources.

(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 purifying the wastewater generated by the dehydration treatment using a water purification device;
A step of producing fresh water from seawater using a fresh water producing apparatus, the fresh water being used at least for the washing process and the dilution process in the alginic acid producing apparatus;
Further, using the fresh water producing apparatus, producing the fresh water from the wastewater purified by the water purification apparatus;
A control program comprising:

Reference Signs List 1 Seaweed resource recovery system 11 Alginic acid production device 12 Water purification device 13 Fresh water production device 14 Hydrogen production device 15 Power generation devices 16 Control device 151 Wind power generation device 152 Solar power generation device 153 Fuel cell

Claims (3)

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 from seawater to be used at least for the washing process and the dilution process in the alginic acid producing apparatus;
At least
The fresh water producing apparatus further produces the fresh water from the wastewater purified by the water purification apparatus.
Seaweed resource utilization system. The system further includes a hydrogen production device that produces hydrogen for use in a fuel cell from at least one of seawater and the freshwater produced by the freshwater production device.
The seaweed resource production system according to claim 1. The hydrogen production device further produces the hydrogen from the wastewater purified by the water purification device.
The seaweed resource production system according to claim 2.

Images