Impurity removal system for vanadyl sulfate electrolyte

Abstract

The utility model belongs to the technical field of flow batteries, and particularly relates to an impurity removal system for vanadyl sulfate electrolyte. The electric adsorption device comprises a plastic partition plate positioned in the middle; a first end plate, a first copper plate, a first bipolar plate, a first liquid storage plate and a first porous carbon plate are sequentially arranged on the left side of the plastic partition plate from outside to inside; a second end plate, a second copper plate, a second bipolar plate, a second liquid storage plate and a second porous carbon plate are sequentially arranged on the right side of the plastic partition plate from outside to inside. The first copper plate, the first bipolar plate, the plastic partition plate, the second bipolar plate and the second copper plate are each provided with a hole channel so that liquid communication between the feeding port and the discharging port can be achieved. The filtering aperture of the first porous carbon plate is larger than that of the second porous carbon plate. The arrangement mode of the porous carbon plates is beneficial for improving the electric impurity removal efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of liquid flow batteries, and in particular relates to an impurity removal system for vanadyl sulfate electrolyte. Background Art

[0002] At present, impurities in vanadyl sulfate electrolyte are mainly removed by evaporation, concentration and desalination of the electrolyte. Evaporation, concentration and desalination is to change the solubility of impurity salts in the vanadyl sulfate electrolyte to make them crystallize, but this process wastes a lot of energy, and when impurities precipitate, some vanadyl sulfate raw materials will be lost, reducing its yield.

[0003] In order to solve the above problems, this application is proposed. Utility Model Content

[0004] The utility model proposes for the first time to use an electrosorption method to remove impurities from a vanadyl sulfate electrolyte. When the original solution of the vanadyl sulfate electrolyte flows through the electrosorption device, under the action of the electric field force, all the impurity salts in the vanadyl sulfate electrolyte are adsorbed on the porous carbon plate, thereby achieving the purpose of removing impurities. Then, by adding deionized water to the pipeline, changing the flow direction of the deionized water, and changing the positive and negative poles of the DC power supply, the salts adsorbed in the activated carbon electrode will be desorbed and enter the deionized water, thereby achieving a cleaning effect, thereby regenerating the activated carbon electrode and allowing it to be repeatedly used.

[0005] The present application provides an impurity removal system for vanadyl sulfate electrolyte, characterized in that the impurity removal system comprises an electric adsorption device 3;

[0006] The electric adsorption device includes: a plastic partition 36 located in the middle;

[0007] The left side of the plastic separator 36 is provided with: a first end plate 31, a first copper plate 32, a first bipolar plate 33, a first liquid storage plate 34 and a first porous carbon plate 35 in sequence from the outside to the inside;

[0008] The right side of the plastic separator 36 is provided with: a second end plate 41, a second copper plate 40, a second bipolar plate 39, a second liquid storage plate 38 and a second porous carbon plate 37 in sequence from outside to inside;

[0009] The first liquid storage plate 34 and the second liquid storage plate 38 both have liquid storage cavities, and the first copper plate 32 and the second copper plate 40 are respectively connected to the positive and negative electrodes of the voltage-stabilized power supply 10;

[0010] The first end plate 31 is provided with a feed port 11, and the second end plate 41 is provided with a discharge port 12.

[0011] The first copper plate 32, the first bipolar plate 33, the plastic separator 36, the second bipolar plate 39 and the second copper plate 40 are all provided with channels to achieve liquid communication between the feed port 11 and the discharge port 12;

[0012] The filtration pore size of the first porous carbon plate 35 is larger than the filtration pore size of the second porous carbon plate 37 .

[0013] The filtration pore size of the first porous carbon plate 35 is larger than the filtration pore size of the second porous carbon plate 37, so that the filtration accuracy of the first porous carbon plate 35 is smaller than the filtration accuracy of the second porous carbon plate 37. In this way, with the flow direction of the liquid, the filtration accuracy of the porous carbon plate gradually increases, which can achieve step-by-step electrosorption filtration and improve the electrosorption filtration efficiency.

[0014] The filtration pore size of the first porous carbon plate 35 or the filtration pore size of the second porous carbon plate 37 is the average filtration pore size of the carbon plate. The filtration pore size is the size of the filter pores on the carbon plate used for electrosorption and filtration of particles.

[0015] The first porous carbon plate 35 or the second porous carbon plate 37 can be a single layer or multiple layers. The filtering pore size of each single layer carbon plate is consistent.

[0016] When the first porous carbon plate 35 or the second porous carbon plate 37 is multi-layered, the filter pore size of each layer may be consistent, and the filter pore sizes of different layers may be inconsistent.

[0017] The material of the porous carbon plate can be carbon cloth or activated carbon fiber felt.

[0018] The mesh size of the carbon cloth can be selected as 300 mesh (corresponding to the filter pore size of 315μm), 500 mesh (corresponding to the filter pore size of 300μm), 800 mesh (corresponding to the filter pore size of 250μm), 1100 mesh (corresponding to the filter pore size of 224μm), and 1400 mesh (corresponding to the filter pore size of 180μm).

[0019] Preferably, the impurity removal system further comprises: a vanadyl sulfate electrolyte stock solution storage tank 1, and a vanadyl sulfate electrolyte refined solution storage tank 4;

[0020] The vanadyl sulfate electrolyte stock tank 1 is connected to the feed port 11 of the electric adsorption device 3 through an inlet pipe, and the discharge port 12 of the electric adsorption device 3 is connected to the vanadyl sulfate electrolyte refined storage tank 4 .

[0021] Preferably, the vanadyl sulfate electrolyte stock tank 1 and the vanadyl sulfate electrolyte refined storage tank 4 are respectively provided with a vent valve 6 .

[0022] Preferably, a valve 5, a lift pump 2 and a flow meter 7 are provided on the inlet pipeline.

[0023] Preferably, a liquid level control valve 8 is provided on the vanadyl sulfate electrolyte refining storage tank 4 .

[0024] Preferably, the feed port 11 is located at the lower part of the first end plate 31, and the discharge port 12 is located at the upper part of the second end plate 41. This is conducive to the full flow of liquid in the electric adsorption device.

[0025] Preferably, the first porous carbon plate 35 or the second porous carbon plate 37 comprises a multi-layer carbon plate, and the multi-layer carbon plates are arranged from large to small in filtration aperture from the feed port 11 to the discharge port 12. The multi-layer is greater than one layer, such as two layers, three layers, four layers, etc.

[0026] The bipolar plate of the present application can be a graphite flexible plate or a conductive plastic, which is attached to the copper plate. The bipolar plate has the following functions: conducting electricity and preventing the electrolyte from corroding the copper plate.

[0027] Compared with the prior art, this application has the following beneficial effects:

[0028] 1. The present application provides an impurity removal system for vanadyl sulfate electrolyte, which is characterized in that the porous carbon plates of the electric adsorption device are arranged from the feed port to the discharge port with the filter aperture from large to small. This arrangement of the porous carbon plates is conducive to improving the efficiency of electric impurity removal. In addition, the utilization efficiency of the porous carbon plates can also be improved, and the replacement cycle of the porous carbon plates can be extended.

[0029] 2. This solution is simple, easy to implement, low-cost, environmentally friendly, and can be fully applied to all-vanadium liquid flow batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the impurity removal system for vanadyl sulfate electrolyte of the present application.

[0031] Figure 2 This is a schematic diagram of the structure of the electric adsorption device of the present application.

[0032] List of reference numerals:

[0033] 1. Vanadyl sulfate electrolyte stock tank, 2. Lifting pump, 3. Electric adsorption device, 31. First end plate, 32. First copper plate, 33. First bipolar plate, 34. First liquid storage plate, 35. First porous carbon plate, 36. Plastic partition, 37. Second porous carbon plate, 38. Second liquid storage plate, 39. Second bipolar plate, 40. Second copper plate, 41. Second end plate, 4. Vanadyl sulfate electrolyte refined storage tank, 5. Valve, 6. Vent valve, 7. Flow meter, 8. Liquid level control valve, 9. Phase-changing switch, 10. Voltage-stabilized power supply, 11. Feed inlet, 12. Discharge outlet. DETAILED DESCRIPTION

[0034] The present application is further described in detail below in conjunction with embodiments.

[0035] Those skilled in the art will appreciate that the following examples are only used to illustrate the present application and should not be considered to limit the scope of the present application. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the art or the product specifications are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0036] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" to another element, it may be directly connected to the other element, or there may be intermediate elements. In addition, the "connection" used herein may include wireless connections.

[0037] In the description of this application, unless otherwise specified, "plurality" means two or more. The terms "inside", "upper", "lower", etc. indicate positions or state relationships based on the positions or state relationships shown in the drawings, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operate in a specific position, and therefore cannot be understood as limiting this application.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application are understood according to specific circumstances.

[0039] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0040] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0041] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. If not otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution. If not otherwise specified, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0042] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0043] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B".

[0044] Example 1

[0045] like Figure 1 As shown, a system for removing impurities from a vanadyl sulfate electrolyte comprises: a vanadyl sulfate electrolyte stock solution storage tank 1, an electric adsorption device 3, and a vanadyl sulfate electrolyte refined storage tank 4.

[0046] The vanadyl sulfate electrolyte stock solution tank 1 is connected to the feed port 11 of the electric adsorption device 3 through an inlet pipe, and the discharge port 12 of the electric adsorption device 3 is connected to the vanadyl sulfate electrolyte refining storage tank 4 .

[0047] The vanadyl sulfate electrolyte stock tank 1 and the vanadyl sulfate electrolyte refined storage tank 4 are respectively provided with vent valves 6 for venting.

[0048] The inlet pipeline is provided with a valve 5, a lift pump 2 and a flow meter 7.

[0049] The liquid level control valve 8 is used to control the liquid level height of the vanadyl sulfate electrolyte refining storage tank 4 .

[0050] The valve 5 and the lift pump 2 are used to control the flow rate of the vanadyl sulfate stock solution in the system. The flow meter 7 is used to detect the flow rate.

[0051] like Figure 1 , the electric adsorption device 3 includes: a plastic partition 36 located in the middle;

[0052] The left side of the plastic separator 36 is provided with: a first end plate 31, a first copper plate 32, a first bipolar plate 33, a first liquid storage plate 34 and a first porous carbon plate 35 in sequence from the outside to the inside;

[0053] The right side of the plastic separator 36 is provided with: a second end plate 41, a second copper plate 40, a second bipolar plate 39, a second liquid storage plate 38 and a second porous carbon plate 37 in sequence from outside to inside;

[0054] The first liquid storage plate 34 and the second liquid storage plate 38 both have liquid storage cavities, and the first copper plate 32 and the second copper plate 40 are respectively connected to the positive and negative electrodes of the voltage-stabilizing power supply 10 provided with a phase-changing switch 9;

[0055] The first end plate 31 is provided with a feed port 11, and the second end plate 41 is provided with a discharge port 12.

[0056] The first copper plate 32, the first bipolar plate 33, the plastic separator 36, the second bipolar plate 39 and the second copper plate 40 are all provided with channels to achieve liquid communication between the feed port 11 and the discharge port 12;

[0057] The filtration pore size of the first porous carbon plate 35 is larger than the filtration pore size of the second porous carbon plate 37 .

[0058] The end plate 31 is made of PVC. The plastic partition 36 is used to support the two porous carbon plates and conduct the fluid.

[0059] The working principle of this impurity removal system is as follows:

[0060] The vanadyl sulfate stock solution is pumped into the electric adsorption device 3 through the feed port 11 by the lifting pump 2, and the electric adsorption device is started. Under the action of the electric field force, the Na in the vanadyl sulfate stock solution is + , Ca 2+ ,Cr 3+ Impurities such as vanadium sulfate move to the porous carbon plate and are adsorbed on the porous carbon plate, thereby achieving the purpose of deep impurity removal and obtaining a refined electrolyte. Then, the refined electrolyte is discharged from the discharge port 12 and flows through the pipeline to the vanadium sulfate electrolyte refining storage tank 4, thereby achieving the preparation of the refined electrolyte.

[0061] In this embodiment, the first porous carbon plate 35 near the feed port 11 is a carbon cloth with a mesh number of 300. The second porous carbon plate 37 near the discharge port 12 is a carbon cloth with a mesh number of 800.

[0062] The first porous carbon plate 35 and the second porous carbon plate 37 have dimensions of 20 cm in length, 15 cm in thickness, and 3 mm in thickness.

[0063] Figure 1 The two first copper plates and the second copper plates 40 and the components therebetween form a set of adsorption modules. The thickness of a single copper plate is 1 mm, and the length×width=20 cm×15 cm.

[0064] The electric adsorption device of this embodiment includes the above 10 sets of adsorption modules, and the copper plates can be shared between adjacent adsorption modules as double-sided electrodes. The pair of copper plates at the two ends is connected to the voltage-stabilized power supply 10. The two ends of the 10 sets of adsorption modules are fixed by a pair of end plates 31. The spacing between adjacent copper plates is 4 cm.

[0065] The working method of the impurity removal system is as follows: connect the power supply of the electric adsorption device and maintain a certain voltage. Under the constant temperature condition of 20°C, a certain volume of vanadyl sulfate solution is pumped into the electric adsorption device at a certain flow rate. The treated effluent enters the vanadyl sulfate solution storage tank. A certain volume of vanadyl sulfate solution is circulated and treated. The VO flowing out of the device is measured every 5 minutes. 2 + ,Cr 3+ , Ca 2+ , K + , Na + , waiting for Cr in vanadyl sulfate 3+ , Ca 2+ , K + , Na + When the concentration of these impurity ions is constant, the device is considered to have reached adsorption equilibrium.

[0066] The content of each component of the vanadyl sulfate solution is: V: 24.68g / L, Cr: 0.09g / L, Ca: 0.06g / L, K: 0.06g / L, Na: 1.58g / L, Si: 0.003g / L, the volume is 1L, and the water flux is 3L / m 2 ·h, the copper plate voltage is 1.6 V. After the vanadyl sulfate solution flows through the electrosorption device, the concentrations of its components are measured as follows: V: 23.76 g / L, Cr: 0.0098 g / L, Ca: 0.008 g / L, K: 0.0079 g / L, Na: 0.066 g / L, Si: 0.0008 g / L, and the ion concentration is characterized by conductivity.

[0067] The results show that: after the electrosorption device, Cr 3+ Removed 91%, Ca 2+ Eliminated 86%, K + Removed 86.8%, Na + 95.8% of the Si was removed, 73.3% of the Si was removed, and only 3.72% of the V was lost, which can be ignored.

[0068] After the system was operated for 30 days, the electrosorption device still discharged liquid smoothly and the liquid output did not decrease.

[0069] Comparative Example 1

[0070] The only difference from Example 1 is that both the first porous carbon plate 35 and the second porous carbon plate 37 are made of carbon cloth with a mesh size of 500.

[0071] The same vanadyl sulfate solution passed through the electric adsorption device of Comparative Example 1: the contents of the components of the vanadyl sulfate solution were: V: 23.95 g / L, Cr: 0.0158 g / L, Ca: 0.013 g / L, K: 0.0138 g / L, Na: 0.276 g / L, Si: 0.0018 g / L.

[0072] The results show that: after the electrosorption device, Cr 3+ 82.4% of Ca was removed 2+ Eliminated 78.3%, K + Removed 77%, Na + 82.5% was removed and 40% of Si was removed.

[0073] After the system of comparative example 1 was operated for 20 days, it was found that the liquid output was significantly reduced and the liquid output was not smooth. The reason was found to be that the filter holes of the first porous carbon plate 35 were blocked by impurities, which also caused the second porous carbon plate 37 to be not fully utilized. In this case, the porous carbon plate needs to be replaced.

[0074] The above results prove that compared with the case where the filtration aperture of the porous carbon plate remains unchanged, the porous carbon plates are arranged from large to small from the feed inlet to the discharge outlet. This arrangement method realizes step-by-step adsorption filtration and can improve the efficiency of electric impurity removal. In addition, it can also improve the utilization efficiency of the porous carbon plate and extend the replacement cycle of the porous carbon plate.

Claims

1. A system for removing impurities from a vanadyl sulfate electrolyte, characterized in that: The impurity removal system comprises an electric adsorption device (3), and the electric adsorption device (3) comprises: a plastic partition (36) located in the middle; The left side of the plastic separator (36) is provided with, from outside to inside: a first end plate (31), a first copper plate (32), a first bipolar plate (33), a first liquid storage plate (34) and a first porous carbon plate (35); The right side of the plastic separator (36) is provided with, from outside to inside, a second end plate (41), a second copper plate (40), a second bipolar plate (39), a second liquid storage plate (38) and a second porous carbon plate (37); The first liquid storage plate (34) and the second liquid storage plate (38) both have a liquid storage cavity, and the first copper plate (32) and the second copper plate (40) are respectively connected to the positive and negative electrodes of the voltage-stabilized power supply (10); The first end plate (31) is provided with a feed port (11), and the second end plate (41) is provided with a discharge port (12). The first copper plate (32), the first bipolar plate (33), the plastic separator (36), the second bipolar plate (39) and the second copper plate (40) are all provided with channels to achieve liquid communication between the feed port (11) and the discharge port (12); The filtering pore size of the first porous carbon plate (35) is larger than the filtering pore size of the second porous carbon plate (37).

2. The impurity removal system for vanadyl sulfate electrolyte according to claim 1, characterized in that: The impurity removal system further comprises: a vanadyl sulfate electrolyte stock solution tank (1), and a vanadyl sulfate electrolyte refined solution storage tank (4); The vanadyl sulfate electrolyte stock tank (1) is connected to the feed port (11) of the electric adsorption device (3) through an inlet pipe, and the discharge port (12) of the electric adsorption device (3) is connected to the vanadyl sulfate electrolyte refining storage tank (4).

3. The impurity removal system for vanadyl sulfate electrolyte according to claim 2, characterized in that: The vanadyl sulfate electrolyte stock tank (1) and the vanadyl sulfate electrolyte refined storage tank (4) are respectively provided with a vent valve (6).

4. The impurity removal system for vanadyl sulfate electrolyte according to claim 2, characterized in that: The inlet pipeline is provided with a valve (5), a lift pump (2) and a flow meter (7).

5. The impurity removal system for vanadyl sulfate electrolyte according to claim 2, characterized in that: The vanadyl sulfate electrolyte refining storage tank (4) is provided with a liquid level control valve (8).

6. The impurity removal system for vanadyl sulfate electrolyte according to claim 1, characterized in that: The feed port (11) is located at the lower part of the first end plate (31), and the discharge port (12) is located at the upper part of the second end plate (41).

7. The impurity removal system for vanadyl sulfate electrolyte according to claim 1, characterized in that: The first porous carbon plate (35) or the second porous carbon plate (37) comprises a plurality of carbon plates, and the plurality of carbon plates are arranged from large to small in filtering pore size from the feed inlet (11) to the discharge outlet (12).

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