KR20160059439A - Salinity gradient power system for electrical infrastructures - Google Patents

Abstract

The present invention relates to a salinity gradient power system which comprises: a water-intake unit for receiving salt water and fresh water; a preprocess unit for preprocessing the received salt water and the fresh water; and a power generation unit provided to generate with a salinity gradient using the preprocessed salt water and the fresh water. According to the present invention, by utilizing abandoned waste water as a generation source of the salinity gradient, the fresh water, which is a source of salinity gradient power generation, is secured, and an environmental pollution problem can be reduced, as well as generating energy from waste resources.

Description

[0001] SALINITY GRADIENT POWER SYSTEM FOR ELECTRICAL INFRASTRUCTURES [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a salinity differential power generation system, and more particularly, to a power generation system that utilizes wastewater that may cause environmental problems as a power generation source of salinity generation power, .

As power consumption increases globally, interest in new energy sources is increasing, and interest in renewable energy that can replace existing fossil fuels is increasing. In the same vein, efforts are being made to find a solution in the ocean with infinite energy potential. Various attempts are being made, such as wave, tidal, temperature difference, and ocean currents. Will contribute greatly to global energy supply and demand. Salinity generation, a technology to produce electricity using the difference in salinity between seawater and fresh water, has a large theoretical potential of about 3.0 TW worldwide, and it is an eco-friendly power generation technology that does not emit greenhouse gases or radioactive materials such as CO ₂ This is a technology that has received much attention in recent years. However, the seawater needed for salinity generation is infinite, and there is also a problem that needs to be addressed such as global awareness of water shortage, excessive energy consumption for production, and geographical location. Therefore, securing fresh seawater source is a very important prerequisite for successful development of salinity generation.

Wastewater, such as effluent from a sewage treatment plant and factory wastewater, is an energy resource that can be used as a very useful freshwater in terms of salinity generation. The total discharge amount of domestic sewage treatment plant is 813,355 m ³ / hr. It is assumed that 451MW and 30% of salinity generation efficiency are converted into a theoretical amount of salinity generation power, and it is possible to produce enormous energy of about 135MW . Since more than 30% of the sewage treatment plant facilities are located close to the coast, they have a very favorable geographical position to be applied to salinity generation. Please note, if calculated based on the electric charging infrastructure demonstration just a treatment plant in the largest Jeju sewage Jeju (dodu), based on the daily emissions 110,000 tons (460 m ³ / hr), salinity car developed theoretical potential is approximately 1.72 Assuming that MW and salinity generation efficiency are 30%, it is possible to produce about 382kW of energy. These figures can be used as energy sources that can build 191 units of home charger (2kW), 48 units of fast charger (7.7kW), and 8 units of fast charger (50kW). In particular, salinity generation technology has a significant reduction in reliance on large energy storage systems (ESS) because unlike wind, solar and technology, load fluctuations in power generation are small and utilization can reach 90% or more. But it is more advantageous to build such an electric charging infrastructure because it can be used for distributed generation.

The warm water discharged from the nuclear power plant is also a useful energy resource which is very helpful to improve the power generation efficiency of the salt water generation power by the water temperature being 30 to 50 degrees higher than the general sea water. It is known that when the domestic nuclear power generation produces 364.6 TWh of power per year, about 50 billion tons of hot water will be discharged. Assuming 3.2 GW of salinity difference and 30% of salinity difference, Which has a potential to produce enormous energy of about 950 MW. Currently, the use of hot water discharged from nuclear power plants as heating resources for agriculture and aquaculture is considered for recycling, but there is no example yet for salinity generation.

Korean Patent Registration No. 10-1261165

An object of the present invention is to secure fresh water, which is a source necessary for salinity generation, by utilizing abandoned wastewater.

Another object of the present invention is to provide a power generation system that utilizes wastewater that may cause environmental problems as a source of power generation for salinity generation, and that is used to construct electricity charging infrastructure.

In order to achieve the above object, a salinity differential power generation system of the present invention comprises: a water intake part for taking brine and fresh water; A pretreatment unit for treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out by the electrode reaction using the electrons generated by the microbial reaction as a precipitate; A power generator for generating salinity difference power using saline and fresh water treated by the pretreatment unit as a source to generate electricity; And a power conversion unit converting the generated power into a form suitable for an electric charging infrastructure.

The salt differential power generation system may further include an activated carbon filtering unit for receiving the fresh water treated by the microbial reaction and filtering residual organic matter in the provided fresh water through activated carbon, And the activated carbon filtering unit may regenerate the activated carbon using the recovered hydrogen.

The salinity difference generation system may further include a pollution monitoring unit for monitoring the electric power produced by the power generation unit and monitoring the degree of contamination of the ion exchange membrane in the power generation unit.

The salt differential power generation system may further include a membrane regeneration unit that physically or chemically cleans the ion exchange membrane when it is confirmed by the membrane pollution monitoring unit that the contamination of the ion exchange membrane has progressed beyond a predetermined level.

The salinity difference generation system may further include an energy storage unit for storing the power generated by the power generation unit, and the energy storage unit may be associated with a renewable energy source.

According to another aspect of the present invention, there is provided a salinity differential power generation method for constructing an electric charging infrastructure, comprising: obtaining brine and fresh water; A pretreatment step of treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out with the precipitate by an electrode reaction using electrons generated by the microbial reaction; A power generation step of generating salinity difference power by using the brine and fresh water treated by the pre-treatment step as a source to generate electric power; And a power conversion step of converting the produced power into a form suitable for an electric charging infrastructure.

If the wastewater is used as a salt water generation power through the technique of the present invention, it will be possible to obtain an opportunity to produce energy from abandoned waste resources, and to develop important technologies capable of reducing environmental pollution problems. In addition, the electric energy produced by salinity generation using waste water discharged from various sources can be utilized in various energy-related facilities such as electric car charging infrastructure, social safety net facility such as lighting and remote monitoring monitoring, and power plant, And will make a significant contribution to policy.

FIG. 1 is a block diagram and a process diagram of a salinity generation system for constructing an electric charging infrastructure according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a salt water generation source of a salt-difference power generation system for constructing an electric charging infrastructure according to an embodiment of the present invention, and a simultaneous pretreatment process of a low-energy sodium oxide and an inorganic material.
FIG. 3 shows the energy balance for simultaneous pre-treatment of oil and minerals in a saline power generation system for constructing an electric charging infrastructure according to an embodiment of the present invention.
FIG. 4 is a schematic diagram showing the operation of the salt-water power generation system using the wastewater in the salt-water power generation system for constructing the electric charging infrastructure according to the embodiment of the present invention, the maintenance, the application of the electric charging infrastructure, and the connection with the existing renewable energy source.
5 is a flowchart illustrating a method of generating a salinity difference for constructing an electric charging infrastructure according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the exemplary embodiments of the present invention, descriptions of techniques which are well known in the art and are not directly related to the present invention will be omitted. This is to omit the unnecessary description so as to convey the key of the present invention more clearly without fading.

FIG. 1 shows a configuration diagram and a process diagram of a salinity generation system for constructing an electric charging infrastructure according to an embodiment of the present invention. Referring to FIG. 1, a salt water generation system 100 for constructing an electric charging infrastructure according to an embodiment of the present invention includes a water intake unit 110 for receiving brine and fresh water; A pretreatment unit 120 for treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out by the electrode reaction using electrons generated by the microbial reaction as a precipitate; A power generation unit 130 generating salinity difference power by using the brine and fresh water treated by the preprocessing unit 120 as a source to generate electricity; And a power conversion unit 140 for converting the generated power into a form suitable for the electric charging infrastructure.

The water intake part 110 acquires fresh water and brine used as a source for salinity generation. Salt water can be seawater, high-concentration brine discharged from seawater desalination, or seawater hot water discharged from a nuclear power plant. Concentration in sea water may be 3.5 wt%, and concentration of high concentration brine discharged from seawater desalination may be 7 wt% or more. Freshwater can be wastewater from rivers and sewage treatment plants. The intake portion 110 may further include a filter for removing suspended matters and microorganisms.

The pretreatment unit 120 simultaneously removes organic matter and inorganic matter (multivalent ions such as Ca and Mg except Na monovalent ions) of the fresh water and brine taken in the water intake unit 110. Since the large amount of organic matter in the fresh water is contained, the membrane contamination due to the organic matter may become serious, and the salt water may contain a large amount of polyvalent ions, . The pretreatment can be pre-treated with oil and minerals simultaneously using Microbial Precipitation Electrodialysis Cell (MPEC).

The pretreatment unit 120 may include an oxidation electrode tank 121 for removing organic matter from fresh water and a reducing electrode tank 122 for removing multivalent ions (inorganic substances) of brine. Fresh water taken in the water intake unit 110 flows into the oxidation electrode tank 121 and brine flows into the reduction electrode tank 122. The oxidation electrode tank 121 includes an oxidation electrode and may include an organism-degrading microorganism attached to the oxidation electrode.

 The saline solution generation system 110 may further include an activated carbon filtering unit 150 for receiving the fresh water treated by the microbial reaction and filtering the remaining organic matter in the fresh water provided through the activated carbon. The activated carbon filtering unit 150 performs an additional pretreatment process at the end of the pretreatment process of the pretreatment unit 120. The activated carbon filtering unit 150 converts the activated carbon into fresh water and brine which have undergone a pretreatment process in the oxidizing electrode tank 121 and the reducing electrode tank 122 to minimize the amount of remaining organic matter, (130). The activated carbon filtering unit 150 can remove 20 to 30% of DOC (Dissolved Organic Carbon) remaining in the fresh water and salt water after the pretreatment. The activated carbon of the activated carbon filter 123 may be GAC (Granular Activated Carbon).

The pretreatment unit 120 can generate and recover hydrogen in the process of treating the multivalent ions. When some energy is applied to the oxidation electrode bath 121, electrons are generated in the oxidation electrode and electrons move toward the reduction electrode in the reduction electrode bath 122. In the reduction electrode vessel 122, electrons are supplied from the oxidation electrode, and the multivalent ions, which are inorganic matters in the seawater, are treated in the form of precipitates from the electrode reaction using electrons, and at the same time, hydrogen can be produced and recovered.

The activated carbon filtering unit 150 can regenerate activated carbon using hydrogen recovered from the pretreatment unit 120.

The saline power generation of the power generation unit 130 may be reverse electrodialysis (RED), pressure retarded osmosis (PRO), or capacitive mixing (CAPMix).

The power generation unit 130 may include an ion exchange membrane when the salt differential power generation system is a reverse electrodialysis method. The ion exchange membrane improves the performance of salinity generation and can build a large capacity salinity generation system. The width of the ion exchange membrane may be 400 to 600 mm. More preferably 500 mm.

The saline solution power generation system 100 may further include a pollution monitoring unit 160 monitoring the power generated by the power generation unit 130 to determine the degree of contamination of the ion exchange membrane used in the power generation unit 130. When it is confirmed by the contamination monitoring unit 160 that the contamination of the ion exchange membrane has advanced by a predetermined level or more, the saline solution power generation system 100 may include a membrane regeneration unit 170 for performing physical or chemical cleaning on the ion exchange membrane, As shown in FIG. The pollution monitoring unit 160 senses that the ion exchange membrane is contaminated by seawater and residual organic matter in the fresh water, and transmits a control signal to the membrane regeneration unit 170 to clean the ion exchange membrane in real time. The ion exchange membrane cleaning method can be cleaned by a physical or chemical cleaning method. The physical cleaning method may be air sparing or osmotic backwashing. In the chemical cleaning method, the organic contaminants generated on the surface of the membrane can be removed by adding NaOH to the fresh water source .

The saline solution power generation system 100 may further include an energy storage unit 180 for storing the power generated by the power generation unit 130. [ The energy storage unit 180 may store excess power generated from the power generation unit 130 and may supply the power to the power conversion unit 140 when necessary to provide continuous power.

The energy storage unit 180 may be associated with a renewable energy source. The renewable energy source can be provided from the renewable energy supply unit 190. The renewable energy supplied from the renewable energy supply unit 190 may be supplied to the preprocessor 120 and the renewable energy not supplied to the preprocessor 120 may be stored in the energy storage unit 180, And supplies it to the power conversion unit 140. [ This can maximize the utilization efficiency of the electric charging infrastructure while compensating for the shortcomings of existing renewable energy. As a result, it can be linked to renewable energy such as wind power and solar power, and can compensate for utilization limit and load fluctuation which are disadvantages of existing renewable energy.

The salinity generation system 100 is connected to an electric charging station 200 that receives the converted electricity from the power conversion unit 150 and provides electricity to the electric charging infrastructure 200. The electric charging station 200 is connected to the electric charging infrastructure 200, Can be supplied to the electric charging infrastructure.

The salinity difference generation method for constructing an electric charging infrastructure according to an embodiment of the present invention includes: obtaining saline and fresh water (S310); A pretreatment step (S320) of treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out by the electrode reaction using the electrons generated by the microbial reaction, as a precipitate; A power generation step (S330) of generating salinity difference power by using saline and fresh water treated by the pre-treatment step as a source to generate power; And a power conversion step (S340) for converting the produced power into a form suitable for the electric charging infrastructure.

Hereinafter, the process steps of the salt differential power generation system according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, fresh water and salt water, which are the sources of salinity generation, are collected through the water intake unit 110. The source for salinity generation is fresh water and salt water. Salt water can be taken from seawater (about 3.5 wt.%), High concentration brine (7 wt.% Or more) discharged from seawater desalination, and seawater discharge water from nuclear power plants. Freshwater can also be obtained from wastewater from rivers and sewage treatment plants. Organics and minerals (in particular, polyvalent ions such as Ca and Mg except Na used as a power generation source) are removed through a preprocessing step in the preprocessing unit 120 by a source obtained through passage through the intake unit 110. In the present invention, the microorganism precipitation electrolysis (MPEC) method is used to simultaneously perform the pretreatment process of oil and minerals. The thus treated source is supplied to the power generation unit 130 that performs the salt-difference power generation to produce electricity. RED, PRO, and Capmix systems can be used for the saline differential power generation system, and the present invention provides an embodiment considering the reverse electrodialysis based salinity generation system. The electricity generated through the salt-difference power generation is converted into electric power according to the type of the charger through the electric power conversion unit 140. Typically, the fast charger is powered by DC and the slow and home charger is powered by AC. Salinity generation can be directly supplied to the electric charging device because it is possible to generate electricity at all times, and the surplus generation amount can be stored in the energy storage unit 180. In this process, it is possible to link with renewable energy sources (solar, wind, etc.) through the renewable energy supply unit (170). Through this hybridization, supplementary utilization rate limit and load variability can do.

FIG. 2 is a conceptual diagram illustrating a salt water generation source of a salt-difference power generation system for constructing an electric charging infrastructure according to an embodiment of the present invention, and a simultaneous pretreatment process of a low-energy sodium oxide and an inorganic material. Referring to FIG. 2, a source necessary for the saline-drainage generation is subjected to a filtering step for removing suspended matters and microorganisms in the water intake step. Each source can be selectively taken to suit the geographical situation in which it is installed. In the case of fresh water, it is advantageous to use waste water from a sewage treatment plant where organic matter is excessively contained in order to apply oil and inorganic pretreatment techniques. However, when a river having a relatively low organic matter concentration is used, . The wastewater thus taken in flows into the oxidation electrode tank 121, and the seawater flows into the reduction electrode tank 122. When a microorganism for decomposing organic matter is attached to the oxidizing electrode of the oxidizing electrode set 121 and a part of necessary electricity is supplied, electrons are generated in the oxidizing electrode set 121 to move toward the reducing electrode of the reducing electrode set 122, The resulting electrons react with seawater to produce polyvalent ions in the form of precipitates, producing hydrogen in this process.

FIG. 3 shows the energy balance for simultaneous pre-treatment of oil and minerals in a saline power generation system for constructing an electric charging infrastructure according to an embodiment of the present invention. Referring to FIG. 3, the energy consumed to treat the raw water of the sewage treatment plant to meet the discharged water standard is about 0.3 kWh / ton. When the MPEC preprocessing method proposed in the present invention is used, the consumed energy is about 0.5 kWh / ton and the amount of hydrogen energy produced is about 0.8 kWh / ton or more. Therefore, the pretreatment technique through the present invention is a breakthrough technology that can simultaneously treat oil and minerals while consuming little energy. Such a low-energy sub-model pretreatment technique can be applied to seawater desalination technology for the production of drinking water, but especially when applied to the pretreatment technology for the source of the system for power generation. The hydrogen thus produced has a purity of about 99% or more, and can be used as an energy source for regeneration of activated carbon, which is a secondary organic substance pretreatment apparatus as shown in FIG. 2, or can be recovered as gas energy to compensate for the supplied energy.

FIG. 4 is a graph showing the operation, maintenance and application of the electric charging infrastructure of the retro-electrodialysis salt-water power generation system using the wastewater of the salinity generation system for constructing the electric charging infrastructure according to the embodiment of the present invention, It is a schematic. Fresh water and brine treated through the pretreatment process are supplied to the power generation unit 130, which is a salt differential power generation device. An ion exchange membrane having a width of 500 mm or more is provided for increasing the capacity of the reverse electrodialysis salt differential power generator of the present invention. All kinds of ion exchange membranes can be used. However, in view of economy, embodiments of the present invention have been carried out using a heterogeneous composite membrane. The contamination of the membrane is closely related to the long-term performance of the power generation unit 130. Therefore, the linkage between monitoring and regeneration is very important. In the present invention, the degree of membrane contamination is monitored through the pollution monitoring unit 160, which can monitor the performance of the power generator 130 from time to time. When the pollution has progressed considerably, the membrane regeneration unit 170 performs physical and chemical cleaning And a system for cleaning the contaminated membrane in real time. The physical cleaning method can be used by air sparing or osmosis. In chemical cleaning, NaOH can be added to the fresh water source during the operation to remove the organic contaminants generated on the surface of the membrane. The electric charging infrastructure application technology of this brine power generation system can enable more efficient operation of energy system by linking with existing renewable energy technology. Existing wind turbines and photovoltaics require a storage system because of utilization rate and load variation. However, since the salinity generation power reaches almost 100%, it can be directly applied to the electric charger through the provision of only the power conversion apparatus (conversion unit 140), and the energy storage unit 180 ) Can also be stored. Also, since the excess energy thus obtained is partially supplied to the preprocessing unit 120, energy efficient process operation is also possible.

Table 1 shows the results of an embodiment of simultaneous pre-treatment of oil and minerals in a salt-water power generation system for constructing an electric charging infrastructure according to an embodiment of the present invention.

In the pretreatment with MPEC, the concentrations of calcium and magnesium in the initial seawater were 1.2 and 1.3 ppm, respectively, and the concentrations of calcium and magnesium were estimated to be about 0.04 and 0.05 ppm after pretreatment. And showed a treatment efficiency of about 90% or more. On the other hand, the treatment of organic matter through MPEC showed 10 ppm after the treatment at the initial 50 ppm, and the efficiency was about 90%. The treated water was treated with activated charcoal filter and showed an additional treatment efficiency of about 50%, and the organic matter concentration in the final treated water was measured to be about 5 ppm.

Table 2 shows the results of the embodiment of the RED salinity generation using the wastewater of the salinity generation system for constructing the electric charging infrastructure according to the embodiment of the present invention.

The temperature of the fresh water was about 25 ℃ and the salinity difference of the effluent of 200 or more ion concentration (mA) of fresh water was higher than that of distilled water. The electrode used was graphite, the concentration of sea water was 3.5 wt.%, And the concentration of effluent was about 0.02 to 0.05 wt.%.

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

100: Salinity differential power generation system 110:
120: preprocessing unit 130:
140: power conversion unit 150: activated carbon filtering unit
160: Pollution monitoring unit 170: Membrane regeneration unit
180: Energy storage unit 190: New & renewable energy source supply unit
200: Electric charging station

Claims (9)

A salt-water power generation system for establishing an electric charging infrastructure,
A water intake part for taking brine and fresh water;
A pretreatment unit for treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out by the electrode reaction using the electrons generated by the microbial reaction as a precipitate;
A power generator for generating salinity difference power using saline and fresh water treated by the pretreatment unit as a source to generate electricity; And
And a power conversion unit for converting the produced power into a form suitable for the electric charging infrastructure
And the salinity differential power generation system.
The method according to claim 1,
Further comprising an activated carbon filtering unit for receiving the fresh water treated by the microbial reaction and filtering residual organic matter in the provided fresh water through activated carbon.
3. The method according to claim 1 or 2,
Wherein the pretreatment unit generates and recovers hydrogen in the process of treating the polyvalent ions.
The method of claim 3,
And the activated carbon filtering unit regenerates the activated carbon using the recovered hydrogen.
The method according to claim 1,
And a pollution monitoring unit for monitoring the power generated by the power generation unit to grasp the degree of contamination of the ion exchange membrane in the power generation unit.
6. The method of claim 5,
Further comprising a membrane regeneration section for physically or chemically cleaning the ion exchange membrane when it is confirmed by the membrane pollution monitoring section that the contamination of the ion exchange membrane has advanced by a predetermined level or more.
The method according to claim 1,
Further comprising an energy storage unit for storing power generated by the power generation unit.
8. The method of claim 7,
Wherein the energy storage unit is associated with a renewable energy source.
A salinity generation method for establishing an electric charging infrastructure,
Obtaining brine and fresh water;
A pretreatment step of treating the organic matter in the fresh water taken up by the microbial reaction and treating the multivalent ions in the brine taken out with the precipitate by an electrode reaction using electrons generated by the microbial reaction;
A power generation step of generating salinity difference power by using the brine and fresh water treated by the pre-treatment step as a source to generate electric power; And
A power conversion step of converting the produced power into a form suitable for the electric charging infrastructure
Wherein the salinity differential power generation method comprises the steps of:

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