Device for purifying and recovering oxygen from ternary positive electrode material sintering tail gas

Abstract

The utility model relates to a device for purifying and recovering oxygen from ternary positive electrode material sintering tail gas. The device comprises a preprocessor, a heat exchanger I, a buffer tank I, a compressor, a heat exchanger II, a buffer tank II, a recoverer, a pressure equalizing tank, a desorbed gas buffer tank, a product gas buffer tank, a vacuum pump, a program control valve and a regulating valve, the feed gas conveying pipeline is connected with the pretreater, the heat exchanger I, the buffer tank I, the compressor, the heat exchanger II and the buffer tank II in sequence and then is connected with the recoverer; the bottom of the recoverer is respectively connected with a desorbed gas buffer tank and a vacuum pump; and the top of the recoverer is connected with a product gas buffer tank. The device is simple in process, high in oxygen yield, high in automation degree, low in investment, low in operation cost, safe, environment-friendly and energy-saving, oxygen with economic benefits in the sintering tail gas can be recycled, it is ensured that the content of the recycled oxygen is larger than or equal to 99%, and the device can be flexibly adjusted according to production requirements.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical gas processing equipment, in particular to a device for purifying and recovering oxygen from sintering tail gas of ternary positive electrode materials. Background Art

[0002] As the proportion of lithium batteries used in new energy vehicles in my country continues to increase, the lithium battery market has broad space and is entering a golden period. Compared with traditional batteries, lithium batteries have a larger capacity at the same volume, and the production, use and recycling processes are green and environmentally friendly, so they have been widely used in consumer electronics and energy storage products. The general process of industrial synthesis of conventional lithium battery ternary positive electrode materials is: weighing and metering of various raw materials, batching, mixing, calcining, crushing and grading, batching, screening, impurity removal, packaging, etc. On this basis, high-nickel ternary positive electrode materials need to use nickel cobalt manganese hydroxide precursors and lithium hydroxide (instead of lithium carbonate) as raw materials, and dope and coat other elements. In the calcination stage, calcination is carried out in a pure oxygen atmosphere.

[0003] The sintering process is the core process and key control point of the production of lithium battery ternary materials. The main control parameters are sintering temperature, sintering time and sintering atmosphere. In terms of sintering atmosphere, the precursors of nickel, cobalt and manganese in the raw materials are all +2, while in high-nickel ternary positive electrode products, such as NCM622 and NCM811, Co is +3, Ni is +2 / +3, and manganese is +4. Therefore, the calcination process of the entire high-nickel ternary positive electrode product must be carried out in a pure oxygen process.

[0004] During the sintering process, a large amount of water vapor, glue gas or acid-base ions generated during the heating process of the material need to be extracted in time through a fan. The volume content of oxygen in the extracted high-temperature kiln exhaust gas is 10-99%; in the actual production of high-nickel, most of the pure oxygen is not used. According to the theory of continuous generation process, the theoretical oxygen content in the exhaust gas discharged by high-nickel is 92%, and the actual measured value is about 93%; the current price of liquid oxygen is about 1,000 yuan / ton, and for every ton of high-nickel material produced, the exhaust gas contains 9,800 yuan of oxygen. If the discharged oxygen is recycled, the production cost of high-nickel positive electrode materials can be reduced.

[0005] A method for treating wastewater and tail gas recycling in a high-nickel ternary material factory (application number 201910212845.X), a negative electrode material sintering tail gas purification device (authorization announcement number CN 218530187U), and a ternary lithium battery kiln tail gas recovery and reuse system and utilization method (authorization announcement number CN 116625132B), etc., all only treat the tail gas by condensation to remove water and filter dust removal, and are unable to remove nitrogen and carbon dioxide in the tail gas, thereby being unable to ensure the content of recovered oxygen.

[0006] Therefore, there is an urgent need for a new device with high efficiency and low energy consumption to recover oxygen from the sintering tail gas of lithium battery positive electrode materials and ensure that the content of recovered oxygen is greater than 99%, which can also be flexibly adjusted according to production requirements. Utility Model Content

[0007] The purpose of the utility model is to solve the above technical problems and provide a device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials, which has simple structure, low operating cost, high degree of automation, high safety performance and low investment.

[0008] In order to achieve the purpose of the above utility model, the specific technical solution of the utility model is:

[0009] A device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials, the device comprising a pre-processor, a heat exchanger I, a buffer tank I, a compressor, a heat exchanger II, a buffer tank II, a recoverer, a vacuum pump, a desorption gas buffer tank and a product gas buffer tank; wherein a raw gas delivery pipeline is sequentially connected to the pre-processor, the heat exchanger I, the buffer tank I, the compressor, the heat exchanger II and the buffer tank II and then connected to the recoverer; the bottom of the recoverer is respectively connected to the desorption gas buffer tank and the vacuum pump; the top of the recoverer is connected to the product gas buffer tank.

[0010] As a better implementation in the present application, a regulating valve is provided between the desorption gas buffer tank and the buffer tank I, that is, the desorption gas buffer tank is connected to the buffer tank I through the regulating valve.

[0011] As a better implementation mode in the present application, the device further comprises a pressure equalizing tank; the pressure equalizing inlet at the top of the recovery device is connected to the pressure equalizing tank.

[0012] As a better implementation method in the present application, a regulating valve is provided between the tower top outlet and the final filling inlet.

[0013] As a better implementation method in the present application, programmable valves are provided at the desorption gas outlet, reverse venting gas outlet, bottom inlet, equalizing pressure inlet, final filling inlet and top outlet of the recovery device, and each programmable valve is connected to the control device.

[0014] As a better embodiment of the present application, the recoverer is provided with a desorption gas outlet, a reverse venting outlet, a bottom inlet, a pressure equalizing inlet, a final charging inlet and a top outlet and their corresponding pipelines; wherein the desorption gas outlet, the reverse venting outlet and the bottom inlet are all arranged at the bottom end of the recoverer; the pressure equalizing inlet, the final charging inlet and the top outlet are all arranged at the top of the recoverer.

[0015] As a better implementation in the present application, the bottom of the recovery tower is connected to the vacuum pump and the desorption gas buffer tank respectively; the top of the recovery tower is connected to the product gas buffer tank.

[0016] As a better implementation mode in the present application, the number of the recyclers is 3-10 (specifically 3, 4, 5, 6, 7, 8, 9, 10), and the recyclers are connected in parallel.

[0017] As a better implementation mode in the present application, the top of the recovery device is connected to the pressure equalizing tank through a pressure equalizing inlet, and the number of the pressure equalizing tanks is 1-2.

[0018] As a preferred embodiment of the present application, the recovery device is filled with a composite adsorbent filler composed of special adsorbents such as alumina, silica gel, and molecular sieves. Among them, the alumina layer accounts for 0-15% of the adsorbent filling height, the silica gel layer accounts for 0-25%, the molecular sieve layer accounts for 60-80%, and the total adsorbent filling height is 100%.

[0019] The working principle of this device is:

[0020] The raw gas (usually at a pressure of 1KPa and a temperature of about 250°C) enters the boundary area of ​​the device. The raw gas first passes through the pre-processor to cool and remove dust, and then enters the compressor after cooling and separation. After the compressor is pressurized, it is cooled and separated and then enters the recovery device. The carbon dioxide, nitrogen and other gases contained in the raw gas are adsorbed by the adsorbent loaded in the recovery device, and high-purity oxygen is transported from the top of the tower to the subsequent process as product gas. After the adsorption is completed, the adsorbed carbon dioxide, nitrogen and other components are desorbed and directly discharged through steps such as reverse release, evacuation, and flushing.

[0021] The whole process is carried out by at least 3 recycling devices working in a cycle with evenly staggered time. The entire switching process is automatically controlled by a pre-set program system to ensure continuous, stable and safe operation of the device.

[0022] The outlet of the recovery tower described in the device is equipped with a regulating valve to stabilize the pressure of the device. The final filling inlet and the tower top outlet pipeline of the device are equipped with regulating valves to control the final filling and flushing gas volume.

[0023] The air for the final filling and flushing steps comes from the venting of the reflux section.

[0024] Compared with the prior art, the positive effects of the utility model are embodied in:

[0025] (1) The device is equipped with a pre-treatment device at the inlet, which can effectively reduce the temperature and remove dust, and protect the adsorbent.

[0026] (ii) A compressor is configured at the raw gas inlet to increase the system adsorption pressure, thereby increasing the adsorption capacity of the adsorbent, enhancing the adsorption separation effect, and improving the yield of recovered oxygen.

[0027] (III) The product gas pipeline is equipped with a product gas buffer tank to ensure a more stable output of the product gas.

[0028] (IV) The heat exchanger and buffer tank before and after the compressor can effectively remove moisture from the raw gas, ensuring the adsorption effect of the adsorbent while greatly extending the service life of the adsorbent.

[0029] (V) By setting up a desorbed gas buffer tank and returning part of the desorbed gas to the raw material inlet after adjustment through a regulating valve, the yield of oxygen can be further improved.

[0030] (VI) This device uses a pressure swing adsorption process to recover and purify oxygen in the combustion tail gas, which can effectively ensure that the content of recovered oxygen is ≥99%, and can also be flexibly adjusted according to production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the connection relationship of various components in the device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials according to the utility model.

[0032] Among them, 1 is a pre-treatment device; 2 is a heat exchanger I; 3 is a buffer tank I; 4 is a compressor; 5 is a heat exchanger II; 6 is a buffer tank II; 7 is a recovery device; 8 is a vacuum pump; 9 is a desorption gas outlet; 10 is a reverse venting gas outlet; 11 is a tower bottom inlet; 12 is a pressure equalizing inlet; 13 is a final charging inlet; 14 is a tower top outlet; 15 is a program-controlled valve; 16 is a regulating valve; 17 is a desorption gas buffer tank; 18 is a pressure equalizing tank; 19 is a product gas buffer tank. DETAILED DESCRIPTION

[0033] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that, in order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Generally, the components of the embodiment of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0037] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0038] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In addition, the present utility model should point out that, in the present utility model, if the specific structure, connection relationship, position relationship, power source relationship, etc. are not specifically written out, the structure, connection relationship, position relationship, power source relationship, etc. involved in the present utility model are all known by technical personnel in this field on the basis of existing technology without creative work.

[0041] Embodiment 1:

[0042] The device for purifying and recovering oxygen from the sintering tail gas of the ternary positive electrode material has a structure as follows Figure 1 As shown, the device includes a preprocessor 1, a heat exchanger Ⅰ2, a buffer tank Ⅰ3, a compressor 4, a heat exchanger Ⅱ5, a buffer tank Ⅱ6, a recoverer 7, a vacuum pump 8, a desorption gas buffer tank 17 and a product gas buffer tank 19; wherein, the raw gas delivery pipeline is sequentially connected to the preprocessor 1, the heat exchanger Ⅰ2, the buffer tank Ⅰ3, the compressor 4, the heat exchanger Ⅱ5 and the buffer tank Ⅱ6 and then connected to the recoverer 7; the bottom of the recoverer 7 is respectively connected to the desorption gas buffer tank 17 and the vacuum pump 8; the top of the recoverer 7 is connected to the product gas buffer tank 19.

[0043] The recovery device is provided with a desorption gas outlet 9, a reverse venting gas outlet 10, a tower bottom inlet 11, a pressure equalizing inlet 12, a final charging inlet 13 and a tower top outlet 14 and corresponding pipelines; wherein, the desorption gas outlet 9, the reverse venting gas outlet 10 and the tower bottom inlet 11 are all arranged at the bottom end of the recovery device 7; the pressure equalizing inlet 12, the final charging inlet 13 and the tower top outlet 14 are all arranged at the top end of the recovery device 7.

[0044] A regulating valve is provided between the outlet of the tower top 14 of the recovery device 7 and the final filling inlet 13; a program-controlled valve 15 is provided on the recovery device 7, and each program-controlled valve 15 is connected to the control device to facilitate automatic control.

[0045] A regulating valve 16 is provided between the desorbed gas buffer tank 17 and the buffer tank I3 , that is, the desorbed gas buffer tank 17 is connected to the buffer tank I3 via the regulating valve 16 .

[0046] The number of the recyclers 7 is 5, and the recyclers 7 are connected in parallel;

[0047] The top of the recovery device 7 is connected to a pressure equalizing tank 18 via a pressure equalizing inlet 12, and the number of the pressure equalizing tank 18 is one.

[0048] The recycler 7 is filled with composite adsorbent fillers composed of special adsorbents such as alumina, silica gel, molecular sieve, etc. Among them, the alumina layer accounts for 0-15% of the adsorbent filling height, the silica gel layer accounts for 0-25%, the molecular sieve layer accounts for 60-80%, and the total adsorbent filling height is 100%.

[0049] The process steps for using the device to purify and recover the tail gas from the sintering of ternary cathode materials are as follows:

[0050] The pressure of the sintering tail gas of the ternary cathode material is about 0.001MPa, the temperature is 250℃, and the gas volume is about 2000Nm 3 / h, the components are shown in the following table:

[0051] Table 1 Composition of the sintering tail gas of lithium battery positive electrode materials (V%)

[0052] composition <![CDATA[N2]]> <![CDATA[CO2]]> <![CDATA[H2O]]> <![CDATA[O2]]> dust V％ 1 0.5 9 89.5 Trace

[0053] The raw gas enters the boundary area of ​​the device for purifying and recovering oxygen from the sintering tail gas of the ternary positive electrode material at ~1KPa and 250℃. The raw gas first passes through the pre-processor 1 for cooling and dust removal, and then enters the compressor 4 after cooling and separation. The compressor 4 is pressurized to 0.2MPa and then enters the recovery device after cooling and separation. After the carbon dioxide, nitrogen and other gases contained in the raw gas are adsorbed by the adsorbent, the high-purity oxygen is transported from the top of the tower to the subsequent section as the product gas. After the adsorption is completed, the adsorbed carbon dioxide, nitrogen and other components are desorbed through the steps of reverse release, evacuation, flushing, etc., part of the desorbed gas is directly vented, and the other part of the desorbed gas is first buffered by the desorbed gas buffer tank, and then adjusted by the regulating valve and returned to the raw material inlet buffer tank I. When the pressure of the recovery device is evacuated to below -0.09MPa, the regeneration of the recovery device is basically completed. Then use part of the product gas to boost its pressure to the adsorption pressure of 0.2MPa, ready to enter the next adsorption process.

[0054] After using the device to treat the tail gas from the sintering of the ternary positive electrode material, a product gas with an oxygen content of ≥99% can be recovered.

[0055] The whole process is cyclically operated by 5 recyclers, which are evenly staggered in time. All switching processes are automatically controlled by a pre-set program system to ensure continuous, stable and safe operation of the device. The cyclic unit processes of each recycler are: A (adsorption) - ED (equal pressure drop) - D (reverse release) - V (vacuuming) - PP (flushing) - ER (equal pressure rise) - FR (final rise) and so on.

[0056] The basic examples and further selected examples in the above utility model can be freely combined to form multiple embodiments, which are all embodiments that can be adopted and claimed for protection in the utility model. In the scheme of the utility model, each selected example can be arbitrarily combined with any other basic example and selected example. Those skilled in the art will know that there are many combinations.

[0057] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

[0058] This background technology section is provided to generally present the context of the present invention, and the work of the currently named inventor, the work to the extent described in this background technology section, and aspects of the description in this section that did not constitute prior art at the time of application are neither explicitly nor implicitly admitted to be prior art of the present invention.

Claims

1. A device for purifying and recovering oxygen from the tail gas of sintering of ternary positive electrode materials, characterized in that: The device comprises a pre-processor (1), a heat exchanger I (2), a buffer tank I (3), a compressor (4), a heat exchanger II (5), a buffer tank II (6), a recovery device (7), a vacuum pump (8), a desorption gas buffer tank (17) and a product gas buffer tank (19); wherein a raw gas delivery pipeline is sequentially connected to the pre-processor (1), the heat exchanger I (2), the buffer tank I (3), the compressor (4), the heat exchanger II (5) and the buffer tank II (6) and then connected to the recovery device (7); the bottom of the recovery device (7) is respectively connected to the desorption gas buffer tank (17) and the vacuum pump (8); and the top of the recovery device (7) is connected to the product gas buffer tank (19).

2. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials according to claim 1, characterized in that: The recovery device (7) is provided with a desorption gas outlet (9), a reverse venting gas outlet (10), a tower bottom inlet (11), a pressure equalizing inlet (12), a final charging inlet (13) and a tower top outlet (14); wherein the desorption gas outlet (9), the reverse venting gas outlet (10) and the tower bottom inlet (11) are all arranged at the bottom end of the recovery device (7); and the pressure equalizing inlet (12), the final charging inlet (13) and the tower top outlet (14) are all arranged at the top end of the recovery device (7).

3. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials according to claim 1 or 2, characterized in that: A regulating valve is provided between the desorbed gas buffer tank (17) and the buffer tank I (3).

4. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in claim 3, characterized in that: The device also includes a pressure equalizing tank (18); a pressure equalizing inlet (12) at the top of the recovery device (7) is connected to the pressure equalizing tank (18).

5. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in claim 2, characterized in that: A regulating valve (16) is provided between the tower top outlet (14) and the final filling inlet (13).

6. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in claim 2, characterized in that: Programmable valves (15) are provided at the desorption gas outlet (9), the reverse venting gas outlet (10), the tower bottom inlet (11), the pressure equalization inlet (12), the final filling inlet (13) and the tower top outlet (14) of the recovery device (7), and each programmable valve (15) is connected to a control device.

7. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in any one of claims 4 to 6, characterized in that: The bottom of the recovery device (7) is connected to a vacuum pump (8) and a desorption gas buffer tank (17) respectively; the top of the recovery device (7) is connected to a product gas buffer tank (19).

8. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in claim 7, characterized in that: The number of the recyclers (7) is 3-10, and the recyclers (7) are connected in parallel.

9. The device for purifying and recovering oxygen from the sintering tail gas of ternary positive electrode materials as claimed in claim 4, characterized in that: The number of the pressure equalizing tanks (18) is 1-2.

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