Waste lithium battery disassembling organic waste gas treatment device and treatment process

Abstract

The invention discloses a waste lithium battery disassembly organic waste gas treatment device and treatment process, and belongs to the technical field of waste gas treatment. By arranging the spraying absorption tower, the concentration of fluorine and phosphorus in subsequent incineration and heat exchange sections can be reduced, so that equipment corrosion is reduced; meanwhile, a concentration and flow adjusting system is arranged in front of the incineration chamber, so that parameters of waste gas entering the incineration chamber are constant, and the incinerator runs stably and is low in energy consumption; besides, by means of the tail low-temperature and low-oxygen waste gas backflow cooling technology, it is guaranteed that the temperature in the incineration chamber is within the optimal interval, smooth combustion is guaranteed, meanwhile, the temperature of incineration flue gas in the incineration chamber and an outlet can be effectively reduced, the oxygen content in the gas phase can be reduced, and corrosion of fluorine and phosphorus to equipment is reduced from two aspects. The alkaline washing tower is arranged at the tail end, fluorine and phosphorus are deeply removed, and ultralow emission of fluorine and phosphorus is achieved. Absorption liquids in the spraying absorption tower and the alkaline washing tower are mixed, so that the fluorine element can be recycled in the form of cryolite, and resource utilization is realized.

Description

Technical Field

[0001] This invention belongs to the field of waste gas treatment technology, specifically relating to a waste lithium battery dismantling organic waste gas treatment device and treatment process. Background Technology

[0002] With the development of the new energy industry, the number of waste lithium batteries has increased rapidly. In the process of recycling waste lithium batteries, the drying evaporation-condensation method is often used to recover the organic electrolyte (mainly composed of VOCs such as carbonates). However, due to the differences in boiling points of different components and condensation efficiency, some uncondensed organic waste gas will still escape, forming low-concentration but complex and fluctuating VOCs waste gas.

[0003] Commonly used thermal incineration technologies (such as TO, RTO, and RCO) have high requirements for the stability of inlet VOCs concentration. When the exhaust gas concentration fluctuates greatly, it will cause drastic changes in the heat of reaction in the incinerator: high concentrations are prone to overheating, while low concentrations require a large amount of auxiliary fuel to maintain the combustion temperature, resulting in increased energy consumption and unstable operation.

[0004] Furthermore, fluorine and phosphorus compounds coexisting in the exhaust gas can corrode incineration and flue gas heat exchange equipment under high temperature and high oxygen conditions, shortening equipment lifespan and increasing costs. Conventional rapid cooling with water not only results in heat loss but also increases the moisture content in the flue gas, exacerbating the corrosion of equipment by fluorine and phosphorus. Traditional technologies that use alkaline spraying to remove fluorine and phosphorus simultaneously absorb organic matter from the exhaust gas, leading to the consumption of large amounts of alkaline raw materials and the generation of large quantities of high-concentration organic wastewater, increasing both raw material input and wastewater treatment costs.

[0005] Based on the above problems, there is an urgent need to develop an effective technology system for treating waste gas from lithium battery dismantling. This system should achieve selective removal of fluorine and phosphorus from the waste gas through effective technology, balance the concentration and flow rate of the waste gas through front-end control methods, meet the continuous and stable operation requirements of the incineration system, and seek optimized technologies to control the concentration of fluorine and phosphorus, incineration temperature and oxygen concentration in the flue gas, so as to avoid corrosion of incineration and heat exchange equipment. Summary of the Invention

[0006] In view of the above-mentioned prior art, the present invention provides a waste lithium battery dismantling organic waste gas treatment device and treatment process to solve the technical problems of high cost and easy corrosion of equipment in existing treatment processes.

[0007] To achieve the above objectives, the technical solution adopted by this invention is to provide a waste lithium battery dismantling organic waste gas treatment device, including a spray absorption tower, a concentration and flow rate regulation system, an incineration chamber, a blower, a heat exchanger, and an alkaline scrubbing tower; the spray absorption tower has a gas inlet and an absorbent liquid outlet at the bottom, and a spray nozzle and a gas outlet at the top; the concentration and flow rate regulation system includes an adsorption box and a buffer tank, the adsorption box is filled with waste activated carbon, the buffer tank is equipped with a gas distributor and a static mixer, and the outlet of the buffer tank is equipped with a flow valve; the inlet and outlet of the adsorption box are respectively connected to the gas outlet and the inlet of the buffer tank, the outlet of the buffer tank is connected to the inlet of the incineration chamber, and the outlet of the incineration chamber is connected to the tube side of the heat exchanger; the outlet of the blower has two branches, one of which is connected to the incineration chamber, and the other is connected to the shell side of the heat exchanger, and the shell side of the heat exchanger is also connected to the incineration chamber; the alkaline scrubbing tower has an air inlet and an alkaline scrubbing liquid outlet at the bottom, and a spray nozzle and an exhaust port at the top; the air inlet is connected to the tube side of the heat exchanger.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the spray absorption tower is equipped with a storage tank, which is connected to the spray head via a pump; the storage tank contains aluminum hydroxide slurry.

[0010] Furthermore, flow valves are installed on both branches at the fan outlet.

[0011] Furthermore, a branch line is provided between the tube side of the heat exchanger and the air inlet of the alkali washing tower, and the branch line is connected to the combustion chamber through a pipe equipped with a reflux pump.

[0012] Furthermore, a mixing chamber is provided between the outlet of the incineration chamber and the heat exchanger; the branch line is connected to the mixing chamber and the incineration chamber through a pipe equipped with a reflux pump.

[0013] Furthermore, the alkaline washing tower is equipped with an alkaline solution tank, which is connected to the spray head via a pump; the alkaline solution tank stores sodium ion-type alkaline solution.

[0014] This invention also discloses a process for treating organic waste gas from the dismantling of waste lithium batteries, the process relying on the aforementioned waste lithium battery dismantling organic waste gas treatment device; specifically including the following steps: S1: The organic waste gas generated during the dismantling of waste lithium batteries is introduced into the spray absorption tower through the gas inlet; the organic waste gas comes into countercurrent contact with the absorption reagent sprayed from the nozzle, and the fluorine and phosphorus in the organic waste gas are absorbed. The resulting absorption liquid is discharged from the absorption liquid outlet. The absorption reagent is aluminum hydroxide slurry; the organic waste gas after the removal of fluorine and phosphorus is discharged from the gas outlet. S2: The organic waste gas after fluorine and phosphorus removal passes through the adsorption box and buffer tank in sequence. After the flow rate and concentration are adjusted, it enters the incineration chamber for incineration at a stable flow rate. S3: Air is introduced into the incineration chamber and / or the shell side of the heat exchanger by a fan; the organic waste gas is mixed with fresh air and / or air that has been heated by the heat exchanger in the incineration chamber before combustion; the generated high-temperature combustion gas is discharged from the outlet of the incineration chamber. S4: High-temperature combustion gas enters the tube side of the heat exchanger, exchanges heat with the air in the shell side, and then enters the alkaline scrubbing tower from the air inlet at the bottom of the alkaline scrubbing tower. It comes into countercurrent contact with the alkaline scrubbing reagent sprayed from the spray head, and the fluorine and phosphorus in the organic waste gas are completely removed. The generated alkaline scrubbing liquid is discharged from the alkaline scrubbing liquid outlet. The alkaline scrubbing reagent is a sodium ion type alkaline solution. The remaining gas is discharged from the exhaust port. S5: The absorbent in S1 is mixed with the alkaline washing solution in S4 to react and generate cryolite, thus realizing the recovery of fluorine.

[0015] Furthermore, the combustion temperature in the incineration chamber of S3 is 550~850℃.

[0016] Furthermore, when the combustion temperature in the incineration chamber exceeds 900°C, part of the organic waste gas after heat exchange in the heat exchanger is returned to the incineration chamber until the combustion temperature is 550~850°C.

[0017] Furthermore, the high-temperature combustion gas is mixed with the organic waste gas that has been heated by the heat exchanger before entering the heat exchanger, until the temperature of the mixed gas drops below 500°C.

[0018] The beneficial effects of this invention are: 1. This invention, by setting up a spray absorption tower, can reduce the concentration of fluorine and phosphorus in subsequent incineration and heat exchange stages, thereby reducing equipment corrosion; simultaneously, fluorine can be recycled and utilized in the form of cryolite. Furthermore, the absorption reagent used in the spray absorption tower of this invention is aluminum hydroxide slurry, which can selectively remove fluorine and phosphorus, avoid the absorption of carbonate substances, and reduce the consumption of alkaline solutions and the generation of organic waste liquid.

[0019] 2. The present invention sets up a VOCs concentration and flow rate regulation system before the incineration chamber to keep the parameters of the exhaust gas entering the incineration chamber constant, so that the incinerator operates stably and consumes little energy.

[0020] 3. This invention utilizes low-temperature, low-oxygen waste gas recirculation cooling technology at the tail end to ensure the temperature in the incineration chamber remains within the optimal range, guaranteeing smooth combustion. Compared to direct air cooling, using low-temperature waste gas as the cooling medium effectively reduces the temperature of the incineration chamber and the outlet flue gas, and lowers the oxygen content in the gas phase, thus reducing the corrosion of the equipment by fluorine and phosphorus from two aspects. Using the heat-exchanged waste gas as a cold source not only effectively reduces the temperature of the incinerator but also does not increase the amount of waste gas generated. Compared to traditional water spray rapid cooling, it saves water and does not affect heat recovery, thus achieving energy conservation and emission reduction.

[0021] 4. The present invention adopts a method combining pre-removing fluorine and phosphorus by washing with aluminum hydroxide, regulating the gas concentration and flow rate to stabilize the combustion process, and reducing the temperature and controlling oxygen by flue gas circulation, which can reduce the corrosion of fluorine and phosphorus on equipment in the incineration and heat exchange stages, effectively extend the service life of the equipment, and reduce the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the waste lithium battery disassembling organic waste gas treatment device in Embodiment 1; Figure 2 is a schematic structural diagram of the waste lithium battery disassembling organic waste gas treatment device in Embodiment 2; Figure 3 is a schematic structural diagram of the waste lithium battery disassembling organic waste gas treatment device in Embodiment 3; Wherein, 1. Spray absorption tower; 2. Gas inlet; 3. Absorption liquid outlet; 4. Nozzle; 5. Gas outlet; 6. Adsorption box; 7. Buffer tank; 8. Incineration chamber; 9. Fan; 10. Heat exchanger; 11. Alkali washing tower; 12. Air inlet; 13. Alkali washing liquid outlet; 14. Spray head; 15. Exhaust port; 16. Liquid storage tank; 17. Alkali liquid tank; 18. Shunt branch; 19. Mixing chamber; Figure 4 is a process flow diagram of the waste lithium battery disassembling organic waste gas treatment process in Embodiment 4. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will make a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0024] Embodiment 1 The present invention discloses a waste lithium battery disassembling organic waste gas treatment device. As Figure 1 shown, the waste lithium battery disassembling organic waste gas treatment device includes a spray absorption tower 1, a concentration and flow rate regulation system, an incineration chamber 8, a fan 9, a heat exchanger 10, and an alkali washing tower 11. Among them, the spray absorption tower 1 is provided with a gas inlet 2 for organic waste gas to enter and an absorption liquid outlet 3 at the bottom, and a nozzle 4 and a gas outlet 5 at the top; the absorption reagent sprayed by the nozzle 4 can effectively absorb fluorine and phosphorus in the organic waste gas. After the organic waste gas enters from the gas inlet 2, it contacts the absorption reagent sprayed by the nozzle 4 in a countercurrent manner, and while exchanging heat, it can absorb fluorine and phosphorus in the organic waste gas to achieve the purpose of reducing the content of fluorine and phosphorus in the organic waste gas. The generated absorption liquid is discharged from the absorption liquid outlet 3; in the present invention, aluminum hydroxide slurry is preferably used as the absorption reagent, which is stored in a liquid storage tank 16 supporting the spray absorption tower 1, and the liquid storage tank 16 is connected to the nozzle 4 through a liquid delivery pump. A small amount of fluorine and phosphorus elements in the waste lithium battery disassembling organic waste gas exist in the form of phosphorus pentafluoride (PF5), hydrogen fluoride (HF), or phosphoric acid (H3PO4). The reaction mechanism of absorbing fluorine by aluminum hydroxide slurry is as follows: (1) Reaction of phosphorus pentafluoride (PF5) with water: PF5 + 4H2O → H3PO4 + 5HF; (2) Reaction of hydrofluoric acid HF with aluminum hydroxide: Al(OH)3 + 3HF → AlF3 + 3H2O; Complexation reaction of HF: In a sufficiently high concentration of HF, AlF3 further reacts with F... - Combined into aluminum fluoride compounds ([AlF) n ] 3−n AlF3+HF→[AlF n ] 3−n +(n-3)H + (n≤6); (3) Reaction of phosphoric acid with aluminum hydroxide: Al(OH)3 + H3PO4 → AlPO4↓ + 3H2O; After the reaction is complete, aluminum phosphate (AlPO4) can be separated into solid and liquid components to obtain a solution of aluminum fluoride complex.

[0025] The organic gas discharged from gas outlet 5 contains various organic compounds. Due to the different boiling points of these organic compounds, the concentration of organic waste gas fluctuates greatly at different operating stages and after drying and condensation, which is detrimental to the stable operation of subsequent treatment equipment. For example, when the VOCs concentration is high, a large amount of heat is released, requiring not only self-combustion but also additional cooling measures to prevent excessive temperature from generating NOx. When the VOCs concentration is low, a large amount of electricity or natural gas is needed to provide heat to meet the combustion temperature. Therefore, this invention requires adjusting the concentration and flow rate of the organic gas before it enters the incineration chamber 8 to ensure a stable flow rate. Figure 1As shown, the concentration and flow regulation system of this invention includes an adsorption box 6 and a buffer tank 7. The adsorption box 6 is filled with waste activated carbon, and the buffer tank 7 is equipped with a gas distributor and a static mixer. A flow valve is installed at the outlet of the buffer tank 7. The inlet and outlet of the adsorption box 6 are connected to the gas outlet 5 and the inlet of the buffer tank 7, respectively, and the outlet of the buffer tank 7 is connected to the inlet of the incineration chamber 8. The organic gas discharged from the gas outlet 5 first enters the adsorption box 6, using waste activated carbon as a concentration pre-regulator. By utilizing the high-concentration adsorption and low-concentration desorption characteristics of activated carbon, the "peak shaving and valley filling" effect is achieved, thus stabilizing the VOCs concentration in the waste gas. That is, when the VOCs concentration in the waste gas is too high, the VOCs in the gas phase are adsorbed onto the activated carbon, reducing the VOCs concentration in the waste gas and achieving the "peak shaving" effect. When the VOCs concentration in the inlet waste gas is too low, the VOCs adsorbed on the activated carbon are released back into the waste gas, achieving the "valley filling" effect. Specifically, conventional processes require activated carbon to have excellent adsorption performance, even for low-concentration organic waste gas. However, in this invention, the activated carbon is required to only adsorb high-concentration VOCs waste gas, while having no adsorption capacity for low-concentration VOCs, or even releasing the adsorbed VOCs. Therefore, waste activated carbon with poor adsorption capacity can meet the requirements, and there is no need to change the temperature of the waste gas to achieve adsorption or desorption, resulting in energy saving. In addition, using waste activated carbon also has the effect of waste recycling. The organic waste gas from the adsorption box 6 enters the buffer tank 7, where it is temporarily stored, mixed, and homogenized. The buffer tank 7 is equipped with a gas distributor and a static mixer to promote the thorough mixing of high and low concentration organic waste gas input at different times. When the upstream waste gas flow suddenly increases, some waste gas is temporarily stored in the buffer tank 7, delaying its downstream transport. When the upstream concentration is low, the waste gas temporarily stored in the buffer tank 7 is slowly released to achieve a stable waste gas flow.

[0026] like Figure 1As shown, the outlet of the incineration chamber 8 is connected to the tube side of the heat exchanger 10; the outlet of the blower 9, used to inject air into the incineration chamber 8, has two branches, one of which is connected to the incineration chamber 8, and the other is connected to the shell side of the heat exchanger 10, which in turn is connected to the incineration chamber 8. The organic waste gas, after its concentration and flow rate are regulated by the concentration and flow rate regulation system, enters the incineration chamber 8 for combustion. The function of the incineration chamber 8 is to incinerate the organic waste gas. Any existing device capable of achieving this purpose is applicable to this invention. Fresh air needs to be introduced into the incineration chamber 8 as a combustion aid. The introduced fresh combustion air is divided into two paths: one path enters the heat exchanger 10, where it indirectly exchanges heat with the high-temperature flue gas. Part of the air after heat exchange is returned to the incineration chamber 8, and the remaining part is used as a high-temperature heat source for plant heating, process heating, or other energy utilization processes, achieving cascaded energy utilization; the other path enters the incineration chamber 8 directly without heat exchange. To stabilize the combustion temperature in the incineration chamber 8 between 550 and 850°C, the introduced fresh combustion air needs to be regulated. Therefore, in a preferred embodiment of the present invention, flow valves are installed on both branches at the outlet of the blower 9. These flow valves are designed to intelligently control the flow rate via an external controller. The intelligent control system dynamically adjusts the ratio of the two air streams based on the VOCs concentration at the inlet of the incineration chamber 8 and the temperature inside the incineration chamber 8. When the VOCs concentration is high, the amount of heat exchange air is reduced to prevent overheating; when the concentration is low, the amount of heat exchange air is increased to supplement the heat and maintain the combustion temperature stable between 550 and 850°C.

[0027] The combustion gas, after heat exchange, enters the alkaline scrubbing tower 11 for alkaline scrubbing to further remove fluorine-containing compounds from the gas. For example... Figure 1 As shown, the alkaline washing tower 11 has an air inlet 12 and an alkaline washing liquid outlet 13 at the bottom, and a spray head 14 and an exhaust port 15 at the top; the air inlet 12 is connected to the tube side of the heat exchanger 10. The solution sprayed from the spray head 14 can effectively absorb fluorine, phosphoric acid and other substances in the combustion gas after heat exchange. After the combustion gas enters from the air inlet 12, it comes into countercurrent contact with the alkaline washing reagent sprayed from the spray head 14, absorbing and washing away the fluorine and phosphorus compounds in the combustion gas, thereby achieving the purpose of removing fluorine and phosphorus compounds; in this invention, sodium ion-type alkaline solution (sodium hydroxide, sodium carbonate, sodium bicarbonate, etc.) is preferred as the alkaline washing reagent, which is stored in the alkaline liquid tank 17 matched with the alkaline washing tower 11. The alkaline liquid tank 17 is connected to the spray head 14 through a pump.

[0028] The absorbent discharged from absorbent outlet 3 mixes with the alkaline washing liquid discharged from alkaline washing liquid outlet 13, and reacts to form sodium hexafluoroaluminate (cryolite), thus achieving the purpose of fluorine resource recovery. The reaction equation is as follows: [AlF n ] 3−n +(n-3)H ++NaF + NaOH → Na3AlF6↓ + 3H2O; [AlF n 3−n +(n - 3)H + +NaF + Na2CO3 / NaHCO3 → Na3AlF6↓ + 3H2O.

[0029] Example 2 The present invention discloses a waste lithium battery disassembly organic waste gas treatment device. As Figure 2 shown, the waste lithium battery disassembly organic waste gas treatment device includes a spray absorption tower 1, a concentration and flow rate adjustment system, an incineration chamber 8, a fan 9, a heat exchanger 10, and an alkali washing tower 11. Among them, a gas inlet 2 for organic waste gas to enter and an absorption liquid outlet 3 are provided at the bottom of the spray absorption tower 1, and a spray head 4 and a gas outlet 5 are provided at the top; the absorption reagent sprayed by the spray head 4 can effectively absorb fluorine and phosphorus in the organic waste gas. After the organic waste gas enters from the gas inlet 2, it contacts the absorption reagent sprayed by the spray head 4 in a countercurrent manner, and while exchanging heat, it can absorb fluorine and phosphorus in the organic waste gas to achieve the purpose of reducing the content of fluorine and phosphorus in the organic waste gas. The generated absorption liquid is discharged from the absorption liquid outlet 3; in the present invention, aluminum hydroxide slurry is preferably used as the absorption reagent, which is stored in a liquid storage tank 16 supporting the spray absorption tower 1, and the liquid storage tank 16 is connected to the spray head 4 through an infusion pump. A small amount of fluorine and phosphorus elements in the waste lithium battery disassembly organic waste gas exist in the form of phosphorus pentafluoride (PF5), hydrogen fluoride (HF), or phosphoric acid (H3PO4). The reaction mechanism of absorbing fluorine by aluminum hydroxide slurry is as follows: (1) Reaction of phosphorus pentafluoride (PF5) with water: PF5 + 4H2O → H3PO4 + 5HF; (2) Reaction of hydrofluoric acid HF with aluminum hydroxide: Al(OH)3 + 3HF → AlF3 + 3H2O; Complexation reaction of HF: In HF with a sufficient concentration, AlF3 further combines with F - to form a fluoroaluminum compound ([AlF n 3−n ): AlF3 + 3HF → [AlF n 3−n +(n - 3)H + (n ≤ 6); (3) Reaction of phosphoric acid with aluminum hydroxide: Al(OH)3 + H3PO4 → AlPO4↓ + 3H2O; After the reaction, aluminum phosphate (AlPO4) can be separated from solid and liquid to obtain a solution of fluoroaluminum complex.

[0030] ​​The organic gas discharged from gas outlet 5 contains various organic compounds. Due to the different boiling points of these organic compounds, the concentration of organic waste gas fluctuates greatly at different operating stages and after drying and condensation, which is detrimental to the stable operation of subsequent treatment equipment. For example, when the VOCs concentration is high, a large amount of heat is released, requiring not only self-combustion but also additional cooling measures to prevent excessive temperature from generating NOx. When the VOCs concentration is low, a large amount of electricity or natural gas is needed to provide heat to meet the combustion temperature. Therefore, this invention requires adjusting the concentration and flow rate of the organic gas before it enters the incineration chamber 8 to ensure a stable flow rate. Figure 2 As shown, the concentration and flow rate regulation system of this invention includes an adsorption tank 6 and a buffer tank 7. A flow valve is installed at the outlet of the buffer tank 7. The adsorption tank 6 is filled with waste activated carbon, and the buffer tank 7 is equipped with a gas distributor and a static mixer. The inlet and outlet of the adsorption tank 6 are connected to the gas outlet 5 and the inlet of the buffer tank 7, respectively. The outlet of the buffer tank 7 is connected to the inlet of the incineration chamber 8. The organic gas discharged from the gas outlet 5 first enters the adsorption tank 6. Waste activated carbon is used as a concentration pre-regulator. Utilizing the high-concentration adsorption and low-concentration desorption characteristics of activated carbon, the system achieves a "peak shaving and valley filling" effect, stabilizing the VOCs concentration in the waste gas. That is, when the VOCs concentration in the waste gas is too high, the VOCs in the gas phase are adsorbed onto the activated carbon, reducing the VOCs concentration in the waste gas and achieving a "peak shaving" effect. When the VOCs concentration in the inlet waste gas is too low, the VOCs adsorbed on the activated carbon are released back into the waste gas, achieving a "valley filling" effect. Specifically, conventional processes require activated carbon to have excellent adsorption performance, even for low-concentration organic waste gas. However, in this invention, the activated carbon is required to only adsorb high-concentration VOCs waste gas, while having no adsorption capacity for low-concentration VOCs, or even releasing the adsorbed VOCs. Therefore, waste activated carbon with poor adsorption capacity can meet the requirements, and there is no need to change the temperature of the waste gas to achieve adsorption or desorption, resulting in energy saving. In addition, using waste activated carbon also has the effect of waste recycling. The organic waste gas from the adsorption box 6 enters the buffer tank 7, where it is temporarily stored, mixed, and homogenized. The buffer tank 7 is equipped with a gas distributor and a static mixer to promote the thorough mixing of high and low concentration organic waste gas input at different times. When the upstream waste gas flow suddenly increases, some waste gas is temporarily stored in the buffer tank 7, delaying its downstream transport. When the upstream concentration is low, the waste gas temporarily stored in the buffer tank 7 is slowly released to achieve a stable waste gas flow.

[0031] like Figure 2As shown, the outlet of the incineration chamber 8 is connected to the tube side of the heat exchanger 10; the outlet of the blower 9, used to inject air into the incineration chamber 8, has two branches, one of which is connected to the incineration chamber 8, and the other is connected to the shell side of the heat exchanger 10, which in turn is connected to the incineration chamber 8. The organic waste gas, after its concentration and flow rate are regulated by the concentration and flow rate regulation system, enters the incineration chamber 8 for combustion. The function of the incineration chamber 8 is to incinerate the organic waste gas. Any existing device capable of achieving this purpose is applicable to this invention. Fresh air needs to be introduced into the incineration chamber 8 as a combustion aid. The introduced fresh combustion air is divided into two paths: one path enters the heat exchanger 10, where it indirectly exchanges heat with the high-temperature flue gas. Part of the air after heat exchange is returned to the incineration chamber 8, and the remaining part is used as a high-temperature heat source for plant heating, process heating, or other energy utilization processes, achieving cascaded energy utilization; the other path enters the incineration chamber 8 directly without heat exchange. To stabilize the combustion temperature in the incineration chamber 8 between 550 and 850°C, the introduced fresh combustion air needs to be regulated. Therefore, in a preferred embodiment of the present invention, flow valves are installed on both branches at the outlet of the blower 9. These flow valves are designed to intelligently control the flow rate via an external controller. The intelligent control system dynamically adjusts the ratio of the two air streams based on the VOCs concentration at the inlet of the incineration chamber 8 and the temperature inside the incineration chamber 8. When the VOCs concentration is high, the amount of heat exchange air is reduced to prevent overheating; when the concentration is low, the amount of heat exchange air is increased to supplement the heat and maintain the combustion temperature stable between 550 and 850°C. Meanwhile, a branch line 18 is provided between the tube side of the heat exchanger 10 and the air inlet 12 of the alkaline scrubbing tower 11. The branch line 18 is connected to the incineration chamber 8 through a pipe equipped with a reflux pump. When the temperature in the incineration chamber 8 exceeds 900℃, in order to avoid corrosion of the equipment by fluoride ions under high temperature and oxygen-rich conditions, part of the organic waste gas after heat exchange in the heat exchanger 10 is returned to the incineration chamber 8 as a dilution medium to participate in combustion, effectively absorbing excess heat, thereby controlling the combustion temperature to 550~850℃.

[0032] The combustion gas, after heat exchange, enters the alkaline scrubbing tower 11 for alkaline scrubbing to further remove fluorine-containing compounds from the gas. For example... Figure 2 As shown, the alkaline washing tower 11 has an air inlet 12 and an alkaline washing liquid outlet 13 at the bottom, and a spray head 14 and an exhaust port 15 at the top; the air inlet 12 is connected to the tube side of the heat exchanger 10. The solution sprayed from the spray head 14 can effectively absorb fluorine, phosphoric acid and other substances in the combustion gas after heat exchange. After the combustion gas enters from the air inlet 12, it comes into countercurrent contact with the alkaline washing reagent sprayed from the spray head 14, absorbing and washing away the fluorine and phosphorus compounds in the combustion gas, thereby achieving the purpose of removing fluorine and phosphorus compounds; in this invention, sodium ion-type alkaline solution (sodium hydroxide, sodium carbonate, sodium bicarbonate, etc.) is preferred as the alkaline washing reagent, which is stored in the alkaline liquid tank 17 matched with the alkaline washing tower 11. The alkaline liquid tank 17 is connected to the spray head 14 through a pump.

[0033] The absorption liquid discharged from the absorption liquid outlet 3 is mixed with the alkali washing liquid discharged from the alkali washing liquid outlet 13, and a reaction occurs to form sodium hexafluoroaluminate (cryolite), achieving the purpose of recovering fluorine resources. The reaction equation is as follows: [AlF n 3−n +(n - 3)H + +NaF + NaOH → Na3AlF6↓ + 3H2O; [AlF n 3−n +(n - 3)H + +NaF + Na2CO3 / NaHCO3 → Na3AlF6↓ + 3H2O.

[0034] Example 3 The present invention discloses a device for treating organic waste gas from the disassembly of waste lithium batteries. As Figure 3 shown, the device for treating organic waste gas from the disassembly of waste lithium batteries includes a spray absorption tower 1, a concentration and flow rate adjustment system, an incineration chamber 8, a fan 9, a heat exchanger 10, and an alkali washing tower 11. Among them, the bottom of the spray absorption tower 1 is provided with a gas inlet 2 for organic waste gas to enter and an absorption liquid outlet 3, and the top is provided with a spray head 4 and a gas outlet 5; the absorption reagent sprayed by the spray head 4 can effectively absorb fluorine and phosphorus in the organic waste gas. After the organic waste gas enters from the gas inlet 2, it contacts the absorption reagent sprayed by the spray head 4 in a countercurrent manner, and while exchanging heat, it can absorb fluorine and phosphorus in the organic waste gas, achieving the purpose of reducing the content of fluorine and phosphorus in the organic waste gas. The generated absorption liquid is discharged from the absorption liquid outlet 3; in the present invention, aluminum hydroxide slurry is preferably used as the absorption reagent, which is stored in a liquid storage tank 16 supporting the spray absorption tower 1, and the liquid storage tank 16 is connected to the spray head 4 through a liquid delivery pump. A small amount of fluorine and phosphorus elements in the organic waste gas from the disassembly of waste lithium batteries exist in the form of phosphorus pentafluoride (PF5), hydrogen fluoride (HF), or phosphoric acid (H3PO4). The reaction mechanism of absorbing fluorine by aluminum hydroxide slurry is as follows: (1) Reaction of phosphorus pentafluoride (PF5) with water: PF5 + 4H2O → H3PO4 + 5HF; (2) Reaction of hydrofluoric acid HF with aluminum hydroxide: Al(OH)3 + 3HF → AlF3 + 3H2O; Complexation reaction of HF: In HF with a sufficient concentration, AlF3 further combines with F - to form a fluoroaluminum compound ([AlF n 3−n ): AlF3 + 3HF → [AlF n 3−n +(n - 3)H + (n ≤ 6); ​​​(3) Reaction of phosphoric acid with aluminum hydroxide: Al(OH)3 + H3PO4 → AlPO4↓ + 3H2O; After the reaction is complete, aluminum phosphate (AlPO4) can be separated into solid and liquid components to obtain a solution of aluminum fluoride complex.

[0035] The organic gas discharged from gas outlet 5 contains various organic compounds. Due to the different boiling points of these organic compounds, the concentration of organic waste gas fluctuates greatly at different operating stages and after drying and condensation, which is detrimental to the stable operation of subsequent treatment equipment. For example, when the VOCs concentration is high, a large amount of heat is released, requiring not only self-combustion but also additional cooling measures to prevent excessive temperature from generating NOx. When the VOCs concentration is low, a large amount of electricity or natural gas is needed to provide heat to meet the combustion temperature. Therefore, this invention requires adjusting the concentration and flow rate of the organic gas before it enters the incineration chamber 8 to ensure a stable flow rate. Figure 3As shown, the concentration and flow regulation system of this invention includes an adsorption box 6 and a buffer tank 7. The adsorption box 6 is filled with waste activated carbon, and the buffer tank 7 is equipped with a gas distributor and a static mixer. A flow valve is installed at the outlet of the buffer tank 7. The inlet and outlet of the adsorption box 6 are connected to the gas outlet 5 and the inlet of the buffer tank 7, respectively, and the outlet of the buffer tank 7 is connected to the inlet of the incineration chamber 8. The organic gas discharged from the gas outlet 5 first enters the adsorption box 6, using waste activated carbon as a concentration pre-regulator. By utilizing the high-concentration adsorption and low-concentration desorption characteristics of activated carbon, the "peak shaving and valley filling" effect is achieved, thus stabilizing the VOCs concentration in the waste gas. That is, when the VOCs concentration in the waste gas is too high, the VOCs in the gas phase are adsorbed onto the activated carbon, reducing the VOCs concentration in the waste gas and achieving the "peak shaving" effect. When the VOCs concentration in the inlet waste gas is too low, the VOCs adsorbed on the activated carbon are released back into the waste gas, achieving the "valley filling" effect. Specifically, conventional processes require activated carbon to have excellent adsorption performance, even for low-concentration organic waste gas. However, in this invention, the activated carbon is required to only adsorb high-concentration VOCs waste gas, while having no adsorption capacity for low-concentration VOCs, or even releasing the adsorbed VOCs. Therefore, waste activated carbon with poor adsorption capacity can meet the requirements, and there is no need to change the temperature of the waste gas to achieve adsorption or desorption, resulting in energy saving. In addition, using waste activated carbon also has the effect of waste recycling. The organic waste gas from the adsorption box 6 enters the buffer tank 7, where it is temporarily stored, mixed, and homogenized. The buffer tank 7 is equipped with a gas distributor and a static mixer to promote the thorough mixing of high and low concentration organic waste gas input at different times. When the upstream waste gas flow suddenly increases, some waste gas is temporarily stored in the buffer tank 7, delaying its downstream transport. When the upstream concentration is low, the waste gas temporarily stored in the buffer tank 7 is slowly released to achieve a stable waste gas flow.

[0036] like Figure 3As shown, the outlet of the incineration chamber 8 is connected to the tube side of the heat exchanger 10; the outlet of the blower 9, used to inject air into the incineration chamber 8, has two branches, one of which is connected to the incineration chamber 8, and the other is connected to the shell side of the heat exchanger 10, which in turn is connected to the incineration chamber 8. The organic waste gas, after its concentration and flow rate are regulated by the concentration and flow rate regulation system, enters the incineration chamber 8 for combustion. The function of the incineration chamber 8 is to incinerate the organic waste gas. Any existing device capable of achieving this purpose is applicable to this invention. Fresh air needs to be introduced into the incineration chamber 8 as a combustion aid. The introduced fresh combustion air is divided into two paths: one path enters the heat exchanger 10, where it indirectly exchanges heat with the high-temperature flue gas. Part of the air after heat exchange is returned to the incineration chamber 8, and the remaining part is used as a high-temperature heat source for plant heating, process heating, or other energy utilization processes, achieving cascaded energy utilization; the other path enters the incineration chamber 8 directly without heat exchange. To stabilize the combustion temperature in the incineration chamber 8 between 550 and 850°C, the introduced fresh combustion air needs to be regulated. Therefore, in a preferred embodiment of the present invention, flow valves are installed on both branches at the outlet of the blower 9. These flow valves are designed to intelligently control the flow rate via an external controller. The intelligent control system dynamically adjusts the ratio of the two air streams based on the VOCs concentration at the inlet of the incineration chamber 8 and the temperature inside the incineration chamber 8. When the VOCs concentration is high, the amount of heat exchange air is reduced to prevent overheating; when the concentration is low, the amount of heat exchange air is increased to supplement the heat and maintain the combustion temperature stable between 550 and 850°C. Meanwhile, a mixing chamber 19 is provided between the outlet of the incineration chamber 8 and the heat exchanger 10; a branch line 18 is provided between the tube side of the heat exchanger 10 and the air inlet 12 of the alkaline scrubbing tower 11, and the branch line 18 is connected to the mixing chamber 19 and the incineration chamber 8 through a pipe equipped with a return pump; when the temperature inside the incineration chamber 8 exceeds 900℃, in order to avoid corrosion of the equipment by fluoride ions under high temperature and oxygen-rich conditions, part of the organic waste gas after heat exchange in the heat exchanger 10 is returned to the incineration chamber 8 as a dilution medium to participate in combustion, effectively absorbing excess heat, thereby controlling the combustion temperature to 760~850℃; and the temperature of the waste gas discharged from the incineration chamber 8 is 550~850℃. Before entering the heat exchanger 10, it is mixed with the organic waste gas after heat exchange in the heat exchanger 10 in the mixing chamber 19 until the temperature of the mixed gas drops below 500℃, thus avoiding corrosion of the heat exchanger by fluoride ions under high temperature conditions.

[0037] The combustion gas, after heat exchange, enters the alkaline scrubbing tower 11 for alkaline scrubbing to further remove fluorine-containing compounds from the gas. For example... Figure 3As shown, the alkaline washing tower 11 has an air inlet 12 and an alkaline washing liquid outlet 13 at the bottom, and a spray head 14 and an exhaust port 15 at the top; the air inlet 12 is connected to the tube side of the heat exchanger 10. The solution sprayed from the spray head 14 can effectively absorb fluorine, phosphoric acid and other substances in the combustion gas after heat exchange. After the combustion gas enters from the air inlet 12, it comes into countercurrent contact with the alkaline washing reagent sprayed from the spray head 14, absorbing and washing away the fluorine and phosphorus compounds in the combustion gas, thereby achieving the purpose of removing fluorine and phosphorus compounds; in this invention, sodium ion-type alkaline solution (sodium hydroxide, sodium carbonate, sodium bicarbonate, etc.) is preferred as the alkaline washing reagent, which is stored in the alkaline liquid tank 17 matched with the alkaline washing tower 11. The alkaline liquid tank 17 is connected to the spray head 14 through a pump.

[0038] The absorbent discharged from absorbent outlet 3 mixes with the alkaline washing liquid discharged from alkaline washing liquid outlet 13, and reacts to form sodium hexafluoroaluminate (cryolite), thus achieving the purpose of fluorine resource recovery. The reaction equation is as follows: [AlF n ] 3−n +(n-3)H + +NaF+NaOH→Na3AlF6↓+3H2O; [AlF n ] 3−n +(n-3)H + +NaF+Na2CO3 / NaHCO3→Na3AlF6↓+3H2O.

[0039] Example 4 A process for treating organic waste gas from the dismantling of waste lithium batteries is described, taking the waste lithium battery dismantling organic waste gas treatment device in Example 3 as an example, illustrating the specific process for treating organic waste gas from the dismantling of waste lithium batteries; the process flow diagram of the waste lithium battery dismantling organic waste gas treatment process is as follows. Figure 4 As shown, the specific steps include: S1: The organic waste gas generated during the dismantling of waste lithium batteries is introduced into the spray absorption tower 1 through the gas inlet 2 for spraying and defluorination; the organic waste gas comes into countercurrent contact with the aluminum hydroxide slurry sprayed from the nozzle 4, the fluorine and phosphorus in the organic waste gas are absorbed, and the generated fluorine-aluminum complex absorption liquid is discharged from the absorption liquid outlet 3; the organic waste gas after defluorination and phosphorus removal is discharged from the gas outlet 5. S2: The organic waste gas after fluorine and phosphorus removal passes through the adsorption box 6 and the buffer tank 7 in sequence for waste gas conditioning; after the flow rate and concentration are adjusted, the organic waste gas enters the incineration chamber 8 at a stable flow rate for incineration. S3: Air is introduced into the incineration chamber 8 and the shell side of the heat exchanger 10 by the fan 9; the organic waste gas is mixed with a certain proportion of fresh air, air after heat exchange by the heat exchanger 10, and gas returning from the branch line 18 in the incineration chamber 8 and then burned. The gas mixing ratio is based on controlling the combustion temperature to about 800°C; the generated high-temperature combustion gas (about 800°C) is discharged from the outlet of the incineration chamber 8; only part of the air after heat exchange by the heat exchanger 10 returns to the incineration chamber 8, and the rest is used as a high-temperature heat source for plant heating, process heating or other energy utilization, realizing the cascade utilization of energy; S4: High-temperature combustion gas enters the mixing chamber 19 and mixes with the gas returning from the branch line 18 until the temperature of the mixed gas drops below 500°C; then it enters the tube side of the heat exchanger 10, exchanges heat with the air in the shell side, and enters the alkaline scrubbing tower 11 from the air inlet 12 at the bottom of the alkaline scrubbing tower 11, where it comes into countercurrent contact with the sodium ion type alkaline solution sprayed from the spray head 14. The fluorine and phosphorus compounds in the organic waste gas are completely removed, and the generated alkaline scrubbing liquid is discharged from the alkaline scrubbing liquid outlet 13; the remaining gas is discharged from the exhaust port 15. S5: The absorbent discharged from absorbent outlet 3 is mixed with the alkaline washing liquid discharged from alkaline washing liquid outlet 13, and a reaction occurs to form sodium hexafluoroaluminate (cryolite), thus achieving the purpose of fluorine resource recovery.

[0040] Although specific embodiments of the present invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims are still within the scope of protection of this patent.

Claims

1. A device for treating organic waste gas from the dismantling of waste lithium batteries, characterized in that: The system includes a spray absorption tower (1), a concentration and flow regulation system, an incineration chamber (8), a blower (9), a heat exchanger (10), and an alkaline washing tower (11). The spray absorption tower (1) has a gas inlet (2) and an absorbent outlet (3) at the bottom, and a nozzle (4) and a gas outlet (5) at the top. The concentration and flow regulation system includes an adsorption tank (6) and a buffer tank (7). The adsorption tank (6) is filled with waste activated carbon, and the buffer tank (7) is equipped with a gas distributor and a static mixer. The outlet of the buffer tank is equipped with a flow valve. The inlet and outlet of the adsorption tank (6) are connected to the gas outlet (5) and the buffer tank, respectively. The inlet of the buffer tank (7) is connected to the inlet of the combustion chamber (8), and the outlet of the combustion chamber (8) is connected to the tube side of the heat exchanger (10). The outlet of the blower (9) has two branches, one of which is connected to the combustion chamber (8) and the other is connected to the shell side of the heat exchanger (10). The shell side of the heat exchanger (10) is then connected to the combustion chamber (8). The bottom of the alkaline washing tower (11) has an air inlet (12) and an alkaline washing liquid outlet (13), and the top has a spray head (14) and an exhaust port (15). The air inlet (12) is connected to the tube side of the heat exchanger (10).

2. The waste lithium battery dismantling organic waste gas treatment device according to claim 1, characterized in that: The spray absorption tower (1) is equipped with a storage tank (16), which is connected to the spray head (4) via a pump; the storage tank (16) contains aluminum hydroxide slurry.

3. The waste lithium battery dismantling organic waste gas treatment device according to claim 1, characterized in that: Flow valves are installed on both branches at the outlet of the fan (9).

4. The waste lithium battery dismantling organic waste gas treatment device according to claim 1, characterized in that: A branch line (18) is provided between the tube side of the heat exchanger (10) and the air inlet (12) of the alkaline washing tower (11). The branch line (18) is connected to the combustion chamber (8) through a pipe equipped with a reflux pump.

5. The waste lithium battery dismantling organic waste gas treatment device according to claim 4, characterized in that: A mixing chamber (19) is provided between the outlet of the incineration chamber (8) and the heat exchanger (10); the branch line (18) is connected to the mixing chamber (19) and the incineration chamber (8) through a pipe equipped with a reflux pump.

6. The waste lithium battery dismantling organic waste gas treatment device according to claim 1, characterized in that: The alkaline washing tower (11) is equipped with an alkaline solution tank (17), which is connected to the spray head (14) via a pump; the alkaline solution tank (17) contains a sodium ion-type alkaline solution.

7. A process for treating organic waste gas from the dismantling of waste lithium batteries, characterized in that, The processing technology relies on the waste lithium battery dismantling organic waste gas treatment device described in any one of claims 1 to 6; specifically, it includes the following steps: S1: The organic waste gas generated during the dismantling of waste lithium batteries is introduced into the spray absorption tower (1) through the gas inlet (2); the organic waste gas comes into countercurrent contact with the absorption reagent sprayed from the nozzle (4), the fluorine and phosphorus in the organic waste gas are absorbed, and the generated absorption liquid is discharged from the absorption liquid outlet (3). The absorption reagent is aluminum hydroxide slurry; the organic waste gas after removing fluorine and phosphorus is discharged from the gas outlet (5). S2: The organic waste gas after fluorine and phosphorus removal passes through the adsorption box (6) and buffer tank (7) in sequence. After the flow rate and concentration are adjusted, it enters the incineration chamber (8) for incineration at a stable flow rate. S3: Air is introduced into the incineration chamber (8) and / or the shell side of the heat exchanger (10) by a blower (9); the organic waste gas is mixed with fresh air and / or air that has been heated by the heat exchanger (10) in the incineration chamber (8) and then burned; the generated high-temperature combustion gas is discharged from the outlet of the incineration chamber (8). S4: The high-temperature combustion gas enters the tube side of the heat exchanger (10), exchanges heat with the air in the shell side, and then enters the alkaline scrubbing tower (11) through the air inlet (12) at the bottom of the alkaline scrubbing tower (11). It comes into countercurrent contact with the alkaline scrubbing reagent sprayed from the spray head (14). The fluorine and phosphorus in the organic waste gas are completely removed, and the generated alkaline scrubbing liquid is discharged from the alkaline scrubbing liquid outlet (13). The alkaline scrubbing reagent is a sodium ion type alkaline solution. The remaining gas is discharged from the exhaust port (15). S5: The absorbent in S1 is mixed with the alkaline washing solution in S4 to react and generate cryolite, thus realizing the recovery of fluorine.

8. The waste lithium battery dismantling organic waste gas treatment process according to claim 7, characterized in that: The combustion temperature in the incineration chamber (8) of S3 is 550~850℃.

9. The waste lithium battery dismantling organic waste gas treatment process according to claim 8, characterized in that: When the combustion temperature in the incineration chamber (8) exceeds 900°C, part of the organic waste gas after heat exchange in the heat exchanger (10) is returned to the incineration chamber (8) until the combustion temperature is 550~850°C.

10. The waste lithium battery dismantling organic waste gas treatment process according to claim 8, characterized in that: Before entering the heat exchanger (10), the high-temperature combustion gas is mixed with the organic waste gas that has been heated by the heat exchanger (10) until the temperature of the mixed gas drops below 500°C.

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