Ultra-highly concentrated seawater desalination process for the recovery of valuable minerals and production of high-purity freshwater

Abstract

According to a preferred embodiment of the present invention, an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater includes introducing seawater through a seawater inlet, degassing the introduced seawater for pretreatment, introducing the pretreated seawater into a seawater concentrator, introducing the seawater concentrated in the seawater concentrator into a concentrated water crystallizer to extract and recover solids (valuable mineral salts), reintroducing the concentrated water produced in the concentrated water crystallizer into the seawater concentrator, and electrolyzing (electrolyzing) distilled water discharged from the seawater concentrator to produce hydrogen (H2). The present invention, having the above configuration, has the advantages of minimizing the amount of seawater intake, reducing the energy cost for recovering valuable minerals, producing high-purity freshwater even under ultra-high concentration conditions, and providing an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater that can be used to generate hydrogen through a water electrolysis process.

Description

[Technical Field]

[0001] This invention relates to a seawater desalination process, and more specifically, to a new concept process that enables the production of highly pure freshwater for hydrogen generation and the recovery of valuable minerals from highly concentrated brine, using an "ultra-high concentration seawater desalination process" consisting of a low-energy, highly efficient, and environmentally friendly seawater concentrator (multiple effect adsorption desalination device, MEAD) and a concentrated water crystallizer (forced circulation separator + centrifuge). [Background technology]

[0002] In recent years, many technologies have been developed to desalinize various types of seawater, including deep-sea water, and produce mineral water from the desalinized water.

[0003] The mineral components contained in deep sea water are water-soluble, which has the advantage of being easily absorbed by the body, making it a very useful mineral source for modern people.

[0004] Common methods for desalination of seawater include membrane distillation (evaporation), evaporation, electrodialysis, and reverse osmosis (RO). The commonly used RO method involves applying a pressure higher than the osmotic pressure to the influent water after pretreatment using a high-pressure pump to obtain fresh water. However, the high pressure increases the flux, resulting in significant pollution, and the need to further increase the pressure to increase the flux results in significant power consumption.

[0005] The basic principle of evaporation is to separate freshwater from seawater by utilizing the property that when a solution is evaporated, only the solvent evaporates and the solute remains. When seawater or saltwater is heated to its boiling point using a high-temperature heat source such as steam, the solvent water evaporates and becomes steam, and the generated steam is then condensed using a low-temperature heat source (such as cooling water) to obtain freshwater. However, this method has the disadvantages of unavoidably forming scale on the heating tubes, which requires chemical cleaning, and of high energy consumption per unit of water produced.

[0006] Electrodialysis (ED) is a method based on the selective migration of ions present in seawater, with ionic groups bound and fixed to the membrane structure, and is composed of cation exchange membranes and anion exchange membranes. Desalination plants were built and put into use about 10 years earlier than reverse osmosis desalination plants, but the development of membranes and modules was slower than reverse osmosis, and the fields of application are limited, so ED is currently lagging behind in terms of use in desalination and other applications.

[0007] The membrane distillation (MD) process involves heating seawater to generate steam, which is passed through a separation membrane to separate the seawater from the steam, and then condensing the steam to produce freshwater. However, this process has drawbacks, such as the slowdown in production speed due to organic matter and other contaminants adhering to the separation membrane, and the deterioration of the quality of the freshwater produced due to insufficient filtering of seawater.

[0008] Meanwhile, in the past, in order to extract and separate mineral components from seawater, a method was used in which seawater was evaporated and concentrated through the desalination process described above, and mineral components such as calcium and magnesium were separated in the form of salts by utilizing differences in solubility.

[0009] However, when separating minerals dissolved in seawater using the above methods, the recovery rate of the minerals is low, proper separation is difficult, and there are problems such as the need for chemical cleaning due to issues such as scale, as well as the high energy consumption. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent No. 10-1791621 (Name: Heat Pump-Based Membrane Distillation Seawater Desalination and Concentration Extraction Device, Registration Date: October 24, 2017) [Patent Document 2] Korean Patent No. 10-1639848 (Name: High-hardness drinking water manufacturing process that complies with drinking water quality standards using NF / RO / ED separation membrane linked system, Registration date: July 8, 2016) Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to improve the above-mentioned problems, and one of its objectives is to provide an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater, which can minimize the amount of seawater intake.

[0012] Another object of the present invention is to provide an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing high-purity fresh water, which can reduce the energy cost of recovering valuable minerals.

[0013] Yet another object of the present invention is to provide an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing high-purity freshwater, which is capable of producing high-purity freshwater even under ultra-highly concentrated conditions and can be used for hydrogen generation by a water electrolysis process.

[0014] The technical problems of the present invention are not limited to those described above, and other technical problems not described will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0015] In order to achieve the above object, a preferred embodiment of the present invention provides an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity fresh water, which comprises introducing seawater through a seawater inlet, degassing the introduced seawater to perform pretreatment, introducing the pretreated seawater into a seawater concentrator, introducing the seawater concentrated in the seawater concentrator into a concentrated water crystallizer to extract and recover solids (valuable mineral salts), reintroducing the concentrated water produced in the concentrated water crystallizer into the seawater concentrator, and electrolyzing (electrolyzing) the distilled water discharged from the seawater concentrator to produce hydrogen (H2).

[0016] In addition, a seawater concentrator in an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention is characterized by including an adsorption-type multi-effect adsorption desalination device (MEAD).

[0017] In addition, a concentrated water crystallizer in an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity fresh water according to a preferred embodiment of the present invention is characterized by including a forced circulation separator and a centrifuge. [Effects of the Invention]

[0018] According to one embodiment of the present invention, it is possible to provide an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity fresh water, which can minimize the amount of seawater intake.

[0019] Furthermore, according to one embodiment of the present invention, it is possible to provide an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing high-purity fresh water, which can reduce the energy cost required for recovering valuable minerals.

[0020] Furthermore, according to one embodiment of the present invention, it is possible to produce high-purity freshwater even under ultra-high concentration conditions, and it is possible to provide an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater that can be used for hydrogen production by a water electrolysis process.

[0021] The effects of the present invention are not limited to those described above, and other effects not described will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a graph showing the change in saltwater concentration with the temperature in an evaporator in an adsorption-type multi-effect evaporation concentration process included in an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention. [Figure 2] 1 is a flow chart conceptually illustrating an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention. [Figure 3] 1 is a graph showing the change in saltwater concentration in an evaporator over time in an adsorptive desalination step included in an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing highly pure freshwater according to a preferred embodiment of the present invention. [Figure 4] 1 is a chart showing the quality of freshwater produced from an adsorptive desalination step included in an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing highly purified freshwater according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

[0024] In describing the embodiments, technical details that are already well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted in order to avoid obscuring the gist of the present invention and to more clearly convey it.

[0025] For the same reasons, some components in the accompanying drawings are exaggerated, omitted, or illustrated in a schematic manner, and the size of each component does not necessarily completely reflect the actual size. The same or corresponding components in each drawing are designated by the same reference numerals.

[0026] FIG. 1 is a graph showing the saltwater temperature in an evaporator with changes in saltwater concentration in an adsorptive desalination (concentration) process included in an ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater, according to a preferred embodiment of the present invention.

[0027] 1, the brine temperature in the evaporator changes with brine concentration in the adsorption-type desalination (concentration) step included in the ultra-high concentration seawater desalination process (100) for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention. Unlike conventional processes (MED, MSF, MVR, RO, etc.), this method has the advantage of a low TBT (Top Brine Temperature), and can achieve ultra-high concentration of seawater while overcoming issues such as scaling and cleaning.

[0028] Referring to FIG. 2, an ultra-high concentration seawater desalination process (100) for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention is characterized in that seawater is introduced through a seawater inlet, the introduced seawater is pretreated by degassing, the pretreated seawater is introduced into a seawater concentrator, the seawater concentrated in the seawater concentrator is introduced into a concentrate crystallizer to extract and recover valuable minerals, and solids (salt) are treated and recovered, the concentrate water by-produced in the concentrate crystallizer is reintroduced into the seawater concentrator, and distilled water discharged from the seawater concentrator is subjected to electrolysis (water electrolysis) to produce hydrogen (H2).

[0029] Here, the seawater concentrator includes a multi-effect adsorption desalination device (MEAD).

[0030] The concentrate crystallizer also includes a forced circulation separator and a centrifuge.

[0031] FIG. 3 is a graph showing the change in saltwater concentration in an evaporator over time in an adsorptive desalination step (100) included in an ultra-highly concentrated seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention.

[0032] Figure 3 shows the change in saltwater concentration in the evaporator over time in the adsorption desalination process, and confirms that there is little degradation in system performance even under conditions of ultra-high concentration of seawater.

[0033] It can also be confirmed that the energy cost for recovering valuable minerals from highly concentrated seawater is extremely low.

[0034] FIG. 4 is a chart showing the quality of freshwater produced from the adsorptive desalination step (100) included in the ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to a preferred embodiment of the present invention.

[0035] Referring to Figure 4, it can be seen that high-purity freshwater can be produced even under ultra-high concentration conditions of seawater, depending on the quality of the freshwater produced by the adsorption-type desalination process.

[0036] Although the present specification and drawings describe preferred embodiments of the present invention, specific terms are used in their general meanings to simply explain the technical content of the present invention and to aid in understanding the invention, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art to which the present invention pertains that, in addition to the embodiments disclosed herein, other modifications based on the technical concept of the present invention can be implemented. [Explanation of symbols]

[0037] 100: Ultra-highly concentrated seawater desalination process for the recovery of valuable minerals and the production of high-purity freshwater

Claims

1. Seawater is introduced through the seawater inlet, The introduced seawater is degassed and pretreated, The pretreated seawater is introduced into a seawater concentrator. The seawater concentrated in the seawater concentrator is introduced into a concentrated water crystallizer to extract and recover solids (valuable mineral salts), The concentrated water produced in the concentrated water crystallizer is reintroduced into the seawater concentrator; The distilled water discharged from the seawater concentrator is electrolyzed (water electrolysis) to produce hydrogen (H 2 ) Ultra-highly concentrated seawater desalination process for the recovery of valuable minerals and the production of high-purity freshwater.

2. The seawater concentrator comprises:

2. The ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to claim 1, characterized in that it includes a multi-effect adsorption desalination device (MEAD).

3. The concentrated water crystallizer comprises:

2. The ultra-high concentration seawater desalination process for recovering valuable minerals and producing high-purity freshwater according to claim 1, characterized in that it comprises a forced circulation separator and a centrifuge.

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