Capacitive deionization seawater desalination device adopting ultrasonic enhanced flowing electrode charging method

Abstract

According to the capacitive deionization seawater desalination device adopting the ultrasonic enhanced flowing electrode charging method, after a positive / negative flowing electrode is charged to adsorb ions, the potential difference of a system is improved by utilizing charges loaded on the surface of the positive / negative flowing electrode, so that the adsorption capacity on opposite-polarity charge ions is enhanced; meanwhile, an ultrasonic field is coupled to one side of a current collector of the flow electrode capacitive deionization device, and the collision contact frequency and the ion migration rate among active particles are improved by utilizing acoustic streaming and acoustic cavitation effects generated by ultrasound, so that the adsorption efficiency and the charge loading capacity of the flow electrode are improved. Compared with the prior art, the invention has the following beneficial effects: 1, the electric potential difference between the positive electrode and the negative electrode is increased by utilizing charges loaded on the surface of the flowing electrode, and the electric field driving force and the attraction force to anisotropic charge ions are enhanced, so that the ion adsorption efficiency is improved; and 2, the ultrasonic field is coupled with the flow electrode capacitive deionization device, so that the collision contact frequency and the ion migration rate among active particles in the flow electrode are improved, and the charge loading capacity of the flow electrode is further improved. And 3, compared with the traditional flow electrode capacitive deionization technology, the capacitive deionization seawater desalination device adopting the ultrasonic enhanced flow electrode charging method has the advantages that the average desalination rate is improved by 223.78% or above, and the charge efficiency is improved from 70% or below to 90% or above.

Description

Technical Field

[0001] The invention relates to a capacitor deionization seawater desalination device with an ultrasonic enhanced flow electrode charging method, belonging to a new seawater desalination device. Background Art

[0002] The mobile electrode capacitive deionization technology is a capacitive deionization technology that couples the positive and negative mobile electrodes with anion and cation exchange membranes. Its adsorption process is similar to the way capacitors store charges. After adsorbing ions, the positive and negative mobile electrodes store a large amount of charge respectively. If these charges are not directly regenerated and released, it may cause energy waste and limit the desalination performance of the mobile electrode capacitive deionization technology. When releasing these charges, researchers often use a bidirectional power supply (usually a DC-DC converter) to discharge the electrodes, which can effectively recover the stored energy. However, this way of recovering energy is to make the active materials in the mobile electrode release the adsorbed ions, and then recycle the active materials. After multiple cycles, its adsorption performance will be greatly reduced, and it cannot continue to adsorb ions during the energy recovery process, thereby greatly increasing the time cost of FCDI technology. In addition, the active materials in the mobile electrode usually have problems with poor dispersibility and low mass transfer efficiency, which leads to a decrease in its charge transfer efficiency, and then reduces the ion adsorption efficiency of the mobile electrode. Therefore, it is a huge challenge to make the mobile electrode in the mobile electrode capacitive deionization technology perform efficient charging and adsorption, and use the charge stored in the adsorption process to improve the desalination performance. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a capacitive deionization seawater desalination device with an ultrasonic enhanced flowing electrode charging method, which can improve the charge transfer efficiency and load capacity of the flowing electrode, and at the same time utilize the charge carried by it to greatly improve the ion adsorption performance of the flowing electrode capacitive deionization device.

[0004] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is: a capacitive deionization seawater desalination device with ultrasonic enhanced flow electrode charging method, comprising an ultrasonic transducer, a flow electrode capacitive deionization device and a flow electrode carrying positive / negative charges;

[0005] In the capacitive deionization seawater desalination device of the ultrasonic enhanced flow electrode charging method, ultrasonic waves directly act on the flow electrode in the current collector, and the violent acoustic flow and acoustic cavitation effects generated by the ultrasonic waves cause fluid turbulence, so that the active particles in the flow electrode move more violently, increase the contact frequency and ion migration rate between the active particles, and thus increase the charge load of the flow electrode. Then, the charge carried in the flow electrode is used to increase the potential difference between the positive and negative electrodes of the system, thereby increasing the system electric field driving force and the attraction to the oppositely charged ions, thereby improving its ion adsorption performance.

[0006] The specific working steps of the above-mentioned capacitive deionization seawater desalination device using the ultrasonic enhanced flow electrode charging method are as follows:

[0007] Step 1: After the mobile electrode capacitive deionization device is built, the ultrasonic transducer is coupled to the graphite current collector, and then the start and stop of the ultrasonic transducer is controlled by the ultrasonic generator, thereby controlling the propagation of ultrasound in the system;

[0008] Step 2: When the mobile electrode capacitive deionization device starts to operate, the ultrasonic transducer is started according to the duty cycle set by the ultrasonic generator, and the ultrasound is transmitted to the flow channel of the current collector, so that a local vortex is formed through the acoustic flow and acoustic cavitation effect, the laminar flow state of the flow field is changed, and the collision contact frequency and ion migration rate between active particles are increased, thereby improving the adsorption efficiency and charge load of the mobile electrode;

[0009] Step three, allow the mobile electrode to perform charging and adsorption for a certain period of time, so that the surface of the electrode is loaded with charges of different electrical properties through the adsorbed ions.

[0010] Step 4: Change the flow direction of the dual-channel peristaltic pump's action pipe and the three-way valve so that the inlet and outlet pipes of the positive flow electrode are connected to the negative electrode of the device, and the inlet and outlet pipes of the negative flow electrode are connected to the positive electrode of the device. Exchange the positive / negative flow electrodes, and increase the potential difference between the positive / negative electrodes through the charge loaded on their surfaces after adsorbing ions, thereby increasing the attraction for ions with opposite charges and thereby improving the ion adsorption efficiency.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The ultrasonic transducer is directly coupled with the current collector, and the acoustic flow and acoustic cavitation effects generated by ultrasound are used to make the active particles in the flow electrode move more violently, increasing the contact frequency and ion migration rate between the active particles, thereby increasing the charge load of the flow electrode by more than 130%;

[0013] 2. The use of mobile electrodes loaded with different electrical charges can, on the one hand, improve the adsorption performance of the mobile electrodes for ions with opposite charges by utilizing the effect of opposite charges attracting each other; on the other hand, the charges with different electrical properties loaded in the mobile electrodes increase the potential difference and electric field driving force between the positive / negative electrodes of the system, thereby enhancing the ion adsorption effect;

[0014] 3. The capacitive deionization device adopts the ultrasonic enhanced flowing electrode charging method, which efficiently utilizes the energy stored in the flowing electrode and greatly improves the ion adsorption performance of the flowing electrode capacitive deionization technology. The ion adsorption performance is improved by more than 220% compared with the traditional flowing electrode capacitive deionization technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0016] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0017] Figure 2 It is a diagram of the coupling mode between the ultrasonic transducer and the current collector of the device of the present invention;

[0018] Figure 3 is the average desalination rate and initial adsorption rate of the device of the present invention and the mobile electrode capacitive deionization device;

[0019] Figure 4 is the average desalination energy consumption and charge efficiency of the device of the present invention and the mobile electrode capacitive deionization device;

[0020] Figure 5 The average desalination rate, charge efficiency and average desalination energy consumption of the device of the present invention and the mobile electrode capacitive deionization device for different charged solutions;

[0021] Figure 6 The average desalination rate, charge efficiency and average desalination energy consumption of the device of the present invention and the mobile electrode capacitive deionization device for real seawater;

[0022] Figure 1 Middle: 1-flow electrode capacitive deionization device, 2-ultrasonic generator, 3-ultrasonic transducer, 4-dual channel peristaltic pump, 5-flow electrode storage tank. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0024] Example 1

[0025] This embodiment provides a capacitive deionization device of an ultrasonic enhanced flow electrode charging method and a method of using the same, which specifically includes the following steps:

[0026] Step 1: Disperse 2.64 g of activated carbon into a 50 mL volume with a concentration of 1.0 g·L -1 The NaCl solution was mixed evenly by a magnetic stirrer to form an activated carbon electrode slurry with a mass fraction of 5%. 5.0 g·L -1 The NaCl aqueous solution was desalinated. The brine flow rate was 20 mL min -1 , the flow rate of the cathode and anode liquid is 40 mL min -1 .

[0027] Step 2: If Figure 1 As shown, a mobile electrode capacitive deionization device is constructed, wherein the ultrasonic transducer is bonded to the current collector in the manner of Figure 2 As shown. While the flowing electrode capacitive deionization device is running, the ultrasonic generator is started synchronously, so that ultrasound acts on the flowing electrode in the current collector, forming local eddies through acoustic streaming and acoustic cavitation effects, changing the laminar flow state of the flow field, increasing the collision contact frequency and ion migration rate between active particles, thereby improving the adsorption efficiency and charge load of the flowing electrode;

[0028] Step 3: Allow the mobile electrode to perform charging and adsorption for a certain period of time, so that the surface of the electrode is loaded with charges of different electrical properties through the adsorbed ions.

[0029] Step 4: Change the flow direction of the dual-channel peristaltic pump's action pipeline and the three-way valve, so that the inlet and outlet pipelines of the positive flow electrode are connected to the negative electrode of the device, and the inlet and outlet pipelines of the negative flow electrode are connected to the positive electrode of the device, and the positive / negative flow electrodes are exchanged. The charge loaded on their surfaces after adsorbing ions increases the potential difference between the positive / negative electrodes, thereby increasing the attraction to ions with opposite charges and thereby improving the ion adsorption efficiency.

[0030] Step 5: During the operation of the device, use a Lei magnetic conductivity meter to detect the ion concentration of the NaCl solution in real time, and use a digital multimeter to monitor the current flowing through the device in real time, and then process the final data.

[0031] Example 2

[0032] The other experimental parameters and experimental steps of this example are the same as those of Example 1, except that the salt solution used in the charge adsorption is 5.0 g·L -1 After exchanging the positive / negative mobile electrodes, 5.0 g·L -1 The desalination of real seawater with high salt content. Compared with the traditional flow electrode capacitive deionization device, the ion adsorption performance is improved by 70%, and the adsorption performance is greatly improved.

[0033] Example 3

[0034] The other experimental parameters and experimental steps of this example are the same as those of Example 1, except that the salt solution used in the charge adsorption is 5.0 g·L -1 After exchanging the positive / negative mobile electrodes, 5.0 g·L -1 The desalination of real seawater with high salt content is carried out. Compared with the traditional mobile electrode capacitive deionization device, the ion adsorption performance is improved by 32.5%, and the adsorption performance is greatly improved.

[0035] Example 4

[0036] The other experimental parameters and experimental steps of this example are the same as those of Example 1, except that the salt solution used in the charge adsorption is 5.0 g·L -1 MgCl2 aqueous solution, after exchanging the positive / negative mobile electrodes, 5.0g·L -1 The desalination of real seawater with high salt content is carried out. Compared with the traditional flow electrode capacitive deionization device, the ion adsorption performance is improved by 45.6%, and the adsorption performance is greatly improved.

[0037] Example 5

[0038] The other experimental parameters and experimental steps of this embodiment are the same as those of embodiment 1, except that the salt water to be desalinated is real seawater of original concentration, and the positive / negative flow electrodes are exchanged after charging and adsorption for a period of time, and the potential difference of the system is increased through the various ions loaded thereon, thereby improving the ion adsorption efficiency. Compared with the traditional flow electrode capacitive deionization device, the ion adsorption performance is improved by 64.9%, and the adsorption performance is greatly improved.

[0039] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A capacitive deionization seawater desalination device using an ultrasonic enhanced flow electrode charging method, characterized in that: The invention comprises an ultrasonic transducer, a flow electrode capacitive deionization device and a flow electrode carrying positive / negative charges.

2. The capacitor deionization seawater desalination device using the ultrasonic enhanced flow electrode charging method according to claim 1, characterized in that: The mobile electrodes in the mobile electrode capacitive deionization device are used to adsorb ions, so that the positive / negative mobile electrodes carry a certain amount of negative / positive charge respectively, thereby increasing the potential difference between the positive / negative electrodes of the system, increasing the attraction for ions with opposite charges, and thus improving the ion adsorption efficiency.

3. The capacitor deionization seawater desalination device using the ultrasonic enhanced flow electrode charging method according to claim 1, characterized in that: The ultrasonic field is coupled to the flowing electrode capacitive deionization device, and the violent acoustic streaming and acoustic cavitation effects generated by ultrasound are used to cause fluid turbulence, making the active particles in the flowing electrode move more violently, increasing the contact frequency and ion migration rate between the active particles, thereby improving the adsorption efficiency and charge load of the flowing electrode.

4. The capacitor deionization seawater desalination device using the ultrasonic enhanced flow electrode charging method as claimed in claim 1, characterized in that: It can be charged to adsorb a variety of different salt solutions and real seawater, and by loading ions with different charges, the potential difference between the positive and negative electrodes of the mobile electrode can be further increased, thereby strengthening the electric field force for adsorbing ions with opposite charges.

5. A capacitive deionization seawater desalination device using an ultrasonic enhanced flow electrode charging method, characterized in that: The specific working steps are: Step 1: After the mobile electrode capacitive deionization device is built, the ultrasonic transducer is coupled to the graphite current collector, and then the start and stop of the ultrasonic transducer is controlled by the ultrasonic generator, thereby controlling the propagation of ultrasound in the system; Step 2: When the mobile electrode capacitive deionization device starts to operate, the ultrasonic transducer is started according to the duty cycle set by the ultrasonic generator, and the ultrasound is transmitted to the flow channel of the current collector, so that a local vortex is formed through the acoustic flow and acoustic cavitation effect, the laminar flow state of the flow field is changed, and the collision contact frequency and ion migration rate between active particles are increased, thereby improving the adsorption efficiency and charge load of the mobile electrode; Step three, allow the mobile electrode to perform charging and adsorption for a certain period of time, so that the surface of the electrode is loaded with charges of different electrical properties through the adsorbed ions. Step 4: Change the flow direction of the dual-channel peristaltic pump's action pipe and the three-way valve so that the inlet and outlet pipes of the positive flow electrode are connected to the negative electrode of the device, and the inlet and outlet pipes of the negative flow electrode are connected to the positive electrode of the device. Exchange the positive / negative flow electrodes, and increase the potential difference between the positive / negative electrodes through the charge loaded on their surfaces after adsorbing ions, thereby increasing the attraction for ions with opposite charges and thereby improving the ion adsorption efficiency.

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