Ion exchange stack assembly and method for operating same

Abstract

The present invention provides an ion exchange stack assembly and a method for operating same, the ion exchange stack assembly being formed of a plurality of ion exchange stacks, each including: an ion exchange membrane having an injection hole formed in at least one of one end or the other end thereof; a gasket positioned on one surface or both surfaces of the ion exchange membrane; and a housing supporting the ion exchange membrane and the gasket, wherein the ion exchange stacks are positioned in parallel, and the ion exchange membranes in the plurality of ion exchange stacks are connected to each other through a flow path.

Description

Ion exchange stack assembly and method of operating the same

[0001] The present invention relates to an ion exchange stack assembly and a method for operating the same.

[0002] The ion exchange stack assembly consists of an ion exchange stack consisting of a housing, ion exchange membrane, and gasket, and external equipment such as a press, electrode plate, and piping suitable for the ion exchange stack.

[0003] Conventionally, the mass production dimensions of ion exchange membranes have been limited, which limits the total processing capacity of ion exchange stack assemblies.

[0004] Recently, as electrodialysis devices have begun to be used in fields such as lithium recovery, issues with processing capacity have arisen, but it is difficult to enlarge the actual equipment due to limitations in the size of the ion exchange membrane.

[0005] In the present invention, the total processing capacity of a single ion exchange stack assembly is expanded without changing the ion exchange membrane, which is a limiting condition among the components of the ion exchange stack, and problems that may arise secondary are resolved.

[0006] In one embodiment of the present invention, an ion exchange stack assembly is provided, which comprises an ion exchange membrane having an injection hole formed at least on one end or the other end; a gasket positioned on one or both sides of the ion exchange membrane; and a housing supporting the ion exchange membrane and the gasket, wherein a plurality of the ion exchange stacks are positioned in parallel, and the ion exchange membranes in the plurality of ion exchange stacks are connected to each other through a flow path.

[0007] The above flow path can be positioned in multiple numbers in the height direction of the ion exchange membrane.

[0008] The above multiple flow passes can be located at the top and bottom of the ion exchange membrane, respectively.

[0009] When the height of the above ion exchange membrane is 100 length%, the passage height of each flow pass can be 0.8 to 16.5 height%.

[0010] The ratio of width to height of the above ion exchange membrane can be 20-40 length%.

[0011] The above flow path may be streamlined in the direction of flow rotation of the solution.

[0012] The above plurality of ion exchange stacks may each have the same area.

[0013] In another embodiment of the present invention, a method for operating an ion exchange stack assembly is provided, comprising: a step of preparing an ion exchange stack including a plurality of ion exchange membranes; and a gasket positioned therebetween, the ion exchange stack including a treatment solution section, a concentration section, and a dilution section formed from the ion exchange membranes; and a step of connecting a plurality of the ion exchange stacks in parallel; wherein the plurality of connected ion exchange stacks have respective treatment solution sections, concentration sections, and dilution sections connected to each other through a flow path, and the concentration of the solution in each stack is uniformly controlled through the flow path.

[0014] The above flow path connects the treatment solution section, the concentration section, and the dilution section within each ion exchange stack, and can be connected to multiple flow paths at the top and bottom of the stack.

[0015] When the height of the above ion exchange membrane is 100 length%, the passage height of each flow pass can be 0.8 to 16.5 height%.

[0016] Performance targets within ion exchange stack assemblies can be improved without modifying ion exchange membranes, which are not easily dimensionalized.

[0017] It can reduce the cost of manufacturing, installing and constructing ion exchange stack assemblies.

[0018] The life of each ion exchange stack can be improved by compensating for performance variations between ion exchange stacks without using separate power and energy.

[0019] Figure 1 is a detailed schematic diagram of an ion exchange stack.

[0020] Figure 2 is a schematic diagram of an assembly having multiple stacks for part A of Figure 1.

[0021] Figure 3 is a cross-sectional view from the side of Figure 2.

[0022] FIG. 4 is a conceptual diagram of a plurality of ion exchange stack assemblies according to one embodiment of the present invention.

[0023] Figure 5 shows the results of evaluating the ion uniformity within each stack according to the passage height of the flow path.

[0024] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0025] In the present invention, an ion exchange stack structure using two or more ion exchange membranes (1, 1-1) and a gasket (2) at the same time was designed using a housing designed as shown in FIGS. 1 to 4.

[0026] Furthermore, to prevent ion imbalances caused by differences in ion exchange membrane performance within each ion exchange stack, ion exchange passages were incorporated into the housing to ensure circulation driven by buoyancy differences. This design change more than doubles the ion exchange area of ​​a single ion exchange stack.

[0027] Specifically, in one embodiment of the present invention, an ion exchange stack assembly is provided, which comprises an ion exchange membrane (1, 1-1) having an injection hole (3) formed at least on one end or the other end; a gasket (2) positioned on one or both sides of the ion exchange membrane (1, 1-1); and a housing (not shown) supporting the ion exchange membrane (1, 1-1) and the gasket (2), wherein a plurality of the ion exchange stacks are positioned in parallel, and the ion exchange membranes in the plurality of ion exchange stacks are connected to each other through a flow path (5-1, 5-2).

[0028] As described above, the chambers (solution chambers) containing the respective ion exchange membranes (1, 1-1) can be interconnected through the flow paths (5-1, 5-2) installed in the housing. Since the performance of multiple stacks cannot be identical, this results in differences in the voltages applied to the two ends. This voltage difference ultimately causes overheating due to overvoltage, and this invention can cause fatal problems for the life of the ion exchange membrane.

[0029] Therefore, it is important to uniformly adjust the concentration of the solution inside the stack so that each membrane can be under similar conditions.

[0030] The above flow passes (5-1, 5-2) may be positioned in multiple numbers in the height direction of the ion exchange membrane (1, 1-1). The multiple flow passes (5-1, 5-2) may be positioned at the top and bottom of the ion exchange membrane (1, 1-1), respectively.

[0031] Specifically, it is preferable to position the solution at both ends of the inlet / outlet. In this case, the uniformity of the solution within the solution chamber can be effectively improved through physical phenomena such as convection / floatation.

[0032] When the height of the above ion exchange membrane (1, 1-1) is 100 length%, the passage height of each flow pass (5-1, 5-2) can be 0.8 to 16.5 height%. This range is a range obtained by operating the assembly designed by the inventor, and shows that the uniformity of the solution does not continue to increase even if the cross-sectional area of ​​the actual flow pass (5-1, 5-2) increases infinitely. Specific experimental data regarding this will be described later.

[0033] For example, when the stack height is 1220 mm, the height range of the ion exchange passages can be approximately 10 to 200 mm.

[0034]

[0035] The ratio of width to height of the above ion exchange membrane (1, 1-1) may be 20-40 length%. This may vary depending on the design of the ion exchange membrane.

[0036] The above flow path (5-1, 5-2) may be streamlined in the direction of flow rotation of the solution. This may vary depending on the design of the housing. Any structure that facilitates the movement of the solution may be appropriately modified.

[0037] The above-described multiple ion exchange stacks may each have the same area. Essentially, the assembly can be designed by calculating the parallel use of multiple stacks with identical conditions. This can be advantageous in terms of overall throughput and device stability.

[0038] In another embodiment of the present invention, a method for operating an ion exchange stack assembly is provided, comprising: a step of preparing an ion exchange stack including a plurality of ion exchange membranes; and a gasket positioned therebetween, the ion exchange stack including a treatment solution section, a concentration section, and a dilution section formed from the ion exchange membranes; and a step of connecting a plurality of the ion exchange stacks in parallel; wherein the plurality of connected ion exchange stacks have respective treatment solution sections, concentration sections, and dilution sections connected to each other through a flow path, and the concentration of the solution in each stack is uniformly controlled through the flow path.

[0039] The above flow path connects the treatment solution section, the concentration section, and the dilution section within each ion exchange stack, and can be connected to multiple flow paths at the top and bottom of the stack.

[0040] When the height of the above ion exchange membrane is 100 length%, the passage height of each flow pass can be 0.8 to 16.5 height%.

[0041]

[0042] Hereinafter, preferred embodiments and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0043] Example

[0044] Bipolar electrodialysis was performed under the following solution and operating conditions.

[0045] The solution used was 0.0001 mol / L lithium hydroxide.

[0046] At this time, the BASE solution composition ratio is Li+ & OH- 95% / SO4 2- & It is composed of 5% impurities such as Na+, but in this example, 5% of the impurities were removed and the experiment was conducted with 100% lithium hydroxide.

[0047] The stack configuration was designed as an ACID-BASE-SALT 3-chamber BPED process, and the solution passages in the feed frame housing were filled with the BASE solution.

[0048] At this time, the speed, pressure, temperature and concentration below were configured by considering the average of each area in Fig. 4.

[0049] Sur_left & Sur_right represent the left and right ion exchange regions in Figure 4. (This is a reference and does not mean the ion exchange channel.)

[0050] When the power was applied to the BPED system with the first stack sur_left having a relative concentration of 0 and sur_right having a concentration of 0.0001 M, the amount of heat generated by the salt acting as resistance of 100 W was applied to each room.

[0051] Buoyancy is generated by the density difference caused by the temperature difference and ion concentration difference of the solution, causing it to circulate through the flow path.

[0052]

[0053]

[0054] When the height of the ion exchange membrane is 100% of the length, the passage height of each flow pass was changed as shown in the table below and each value was measured.

[0055] [Table 1]

[0056]

[0057] The results are also shown in Fig. 5.

[0058] When the height of the ion exchange membrane is 100% of the length, it was found that as the passage height ratio of each flow pass increases, the difference in the average concentration between the left and right sides of the ion exchange area decreases and then increases again in the 0.16 section.

[0059] The present invention is not limited to the above-described embodiments, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[0060] [Explanation of symbols]

[0061] 1, 1-1: Ion exchange membrane

[0062] 2: Gasket

[0063] 3: Injection hole

[0064] 4: Spacer

[0065] 5-1, 5-2: Flow path

[0066] 6: End plate

[0067] 7: Inlet

[0068] 8: Screw

Claims

1. An ion exchange stack including an ion exchange membrane having an injection hole formed at least on one end or the other end; a gasket positioned on one or both sides of the ion exchange membrane; and a housing supporting the ion exchange membrane and the gasket. The above ion exchange stacks are positioned in multiple parallel positions, An ion exchange stack assembly in which ion exchange membranes within the above-described plurality of ion exchange stacks are connected to each other through a flow path.

2. In paragraph 1, An ion exchange stack assembly wherein the above fluid passes are positioned in multiple numbers in the height direction of the ion exchange membrane.

3. In paragraph 2, An ion exchange stack assembly wherein the plurality of flow passes are respectively positioned at the top and bottom of the ion exchange membrane.

4. In paragraph 3, An ion exchange stack assembly, wherein the passage height of each flow pass is 0.8 to 16.5 height% when the height of the ion exchange membrane is 100 length%.

5. In paragraph 4, An ion exchange stack assembly wherein the ratio of width to height of the ion exchange membrane is 20-40 length %.

6. In paragraph 5, An ion exchange stack assembly wherein the above flow path is streamlined in the direction of flow rotation of the solution.

7. In paragraph 6, An ion exchange stack assembly wherein the above plurality of ion exchange stacks each have the same area.

8. A step of preparing an ion exchange stack including a plurality of ion exchange membranes; and a gasket positioned between them, and including a treatment solution section, a concentration section, and a dilution section formed from them; and A step of connecting a plurality of ion exchange stacks in parallel; comprising; The above-mentioned multiple connected ion exchange stacks are each connected to each other through a flow path through a treatment solution section, a concentration section, and a dilution section. A method for operating an ion exchange stack assembly, wherein the concentration of a solution in each stack is uniformly controlled through the above-described flow path.

9. In paragraph 8, A method for operating an ion exchange stack assembly, wherein the above-mentioned flow paths connect the treatment solution section, the concentration section, and the dilution section within each ion exchange stack, respectively, and connect the upper and lower sections of the stack with a plurality of flow paths.

10. In paragraph 8, A method for operating an ion exchange assembly, wherein when the height of the ion exchange membrane is 100 length%, the passage height of each flow pass is 0.8 to 16.5 height%.

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