Fluorine removal and fluorine recovery device
The fluorine and nitrogen anode defluorination and fluorine recovery and utilization device solves the problems of severe exothermic reaction and resource waste in the treatment of fluorine tail gas in sulfur hexafluoride production, realizes efficient recovery and utilization of fluorine, and extends the service life of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANDA OPTOELECTRONICS (ZIBO) CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-06-16
AI Technical Summary
In the current sulfur hexafluoride production process, the treatment of high-concentration fluorine gas generated during the electrolytic fluorine production and purification process presents problems such as violent exothermic reactions, excessive equipment temperature rise, increased energy consumption, waste of fluorine resources, incomplete reaction, and equipment corrosion.
The device employs a fluorine-nitrogen anode defluorination and fluorine recovery and utilization unit, which includes a sulfur reactor, a defluorination tower, a water washing tower, an alkaline washing tower, and a membrane separation tower. Sulfur hexafluoride is generated through a sulfur reaction, and adsorption beds and condensation coils are installed in each tower to achieve effective recovery and utilization of fluorine.
This effectively prevents fluorine gas from entering the water washing tower and causing an exothermic reaction, reduces the risk of equipment damage, improves the utilization rate of fluorine gas, reduces energy consumption and NaOH consumption, and extends the equipment life.
Smart Images
Figure CN224358225U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to fluorine tail gas treatment system technical field, concretely relates to fluorine nitrogen gas anode defluorination and fluorine recovery and utilization device. BACKGROUND
[0002] In the production of sulfur hexafluoride, the traditional treatment method of high-concentration fluorine gas tail gas generated in the electrolytic fluorine production and purification process has significant defects. The existing process directly introduces fluorine-containing tail gas into a water washing tower for water absorption treatment (reaction formula: 2F2+2H2O→4HF+O2+large amount of heat). This process is accompanied by intense heat release, which leads to excessive temperature rise of the equipment, and a strong cooling system needs to be additionally configured, increasing energy consumption and posing a risk of equipment deformation; at the same time, fluorine gas reacts with water to generate low-value hydrofluoric acid, causing waste of high-activity fluorine resources (utilization rate less than 40%).
[0003] Although some enterprises add a sulfur reactor (reaction formula: S+3F2→SF6) to the tail gas path to convert fluorine gas into sulfur hexafluoride product, the existing serial equipment layout still has key defects: incomplete reaction, residual unreacted fluorine gas at the outlet of the sulfur reactor, continued heat release after entering the water washing tower, leading to out-of-control temperature of the water washing tower; product loss, high-pressure spraying in the water washing tower causes part of the sulfur hexafluoride to be dissolved by liquid droplets, resulting in product loss; system corrosion, the caustic washing tower needs to treat the HF not removed by the water washing tower, aggravating the consumption of NaOH and the risk of salt crystallization blockage. INVENTION CONTENTS
[0004] The utility model solves the technical problems existing in the prior art, provides fluorine nitrogen gas anode defluorination and fluorine recovery and utilization device, fluorine gas is converted into sulfur hexafluoride through sulfur reaction, the service life of tail gas equipment is increased, fluorine gas is recycled and utilized, waste is reduced, the electrolytic process of the electrolytic cell is more easily controlled artificially during the continuous reaction process, and the probability of positive pressure of the electrolytic cell is reduced.
[0005] The fluorine nitrogen gas anode defluorination and fluorine recovery and utilization device comprises a sulfur reactor, a defluorination tower, a water washing tower, a caustic washing tower and a membrane separation tower, the bottom of the sulfur reactor is connected with a fluorine-containing tail gas collecting pipe, the outlet of reaction gas of the sulfur reactor is connected with the bottom gas inlet of a precooling demister, the top gas outlet of the precooling demister is connected with the bottom gas inlet of the defluorination tower, the top gas outlet of the defluorination tower is connected with the bottom gas inlet of the water washing tower, the top gas outlet of the water washing tower is connected with the bottom gas inlet of the caustic washing tower, the top gas outlet of the caustic washing tower is connected with the gas inlet of a deep dryer, the gas outlet of the deep dryer is connected with the membrane separation tower, and the enrichment gas outlet of the membrane separation tower is connected with a fan.
[0006] Preferably, the tail gas gas outlet of the membrane separation tower is connected with a tail gas treatment system, SF6 (high boiling point) is enriched on the high-pressure side of the membrane and is output from the top, and the tail gas is discharged from the side to the tail gas treatment system.
[0007] Preferably, the outer layer of the sulfur reactor is provided with an electric heating layer to maintain the reaction temperature.
[0008] Preferably, the outer layer of the precooling demister is provided with a condenser coil layer to cool the gas, and the condensate at the bottom is periodically discharged.
[0009] Preferably, the pre-cooling demister has an internal demister layer, which can be electrostatically energized to remove acid mist, etc.
[0010] Preferably, the defluorination tower has an adsorption bed inside, which can be filled with activated alumina / special adsorbent.
[0011] Preferably, a fluoride concentration monitor is installed on the outlet pipe of the defluorination tower.
[0012] Preferably, the top of the water washing tower is equipped with a spray pipe, so that the gas and the circulating water come into contact in a countercurrent manner.
[0013] Preferably, the alkaline washing tower is equipped with an online pH monitor.
[0014] Preferably, the deep dryer is equipped with a molecular sieve bed, type 3A or 4A.
[0015] The working steps of the fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model are as follows:
[0016] (1) Fluorine and nitrogen anodes and other fluorine-containing tail gases enter the sulfur reactor through the fluorine-containing tail gas collection pipe. Under the temperature control of the electric heating layer, they react with sulfur to generate low-fluorine sulfides. The reaction gas enters the pre-cooling demister, is cooled by the condenser coil layer, and removes droplets and particulate matter by passing through the demister layer.
[0017] (2) The gas enters from the bottom of the defluorination tower and is further defluorinated by the adsorption bed; the fluorine concentration monitor detects the purity of the outlet gas in real time.
[0018] (3) The gas enters the water washing tower, where water is sprayed from the top spray pipe to wash and dissolve residual acidic substances. The gas then enters the alkali washing tower, where it reacts with the alkali solution to neutralize the acidic gas; the pH online monitor regulates the concentration of the alkali solution. The gas passes through the molecular sieve bed of the deep dryer to adsorb moisture, achieving the low dew point required for membrane separation.
[0019] (4) The dry gas enters the membrane separation tower. Due to the difference in permeation rate, sulfur hexafluoride is concentrated at the enrichment gas outlet and then pressurized by a blower for use in the sulfur hexafluoride production workshop. The low-fluorine tail gas after membrane separation enters the tail gas treatment system and is discharged in compliance with standards after catalytic decomposition or adsorption.
[0020] Compared with the prior art, the beneficial effects of this utility model are:
[0021] (1) The fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model intercepts the residual fluorine gas at the outlet of the sulfur reactor through the adsorption bed of the defluorination tower, and prevents the fluorine gas from entering the water washing tower and causing an exothermic reaction, fundamentally solving the problem of water washing tower temperature runaway, avoiding equipment deformation and strong cooling energy consumption.
[0022] (2) In the fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model, the sulfur hexafluoride generated by the sulfur reaction enters the membrane separation tower, reducing the loss.
[0023] (3) The fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model has a water washing tower for pretreatment of sulfide gas, and the alkali washing tower only needs to neutralize trace amounts of acidic substances; combined with the pH online monitor for precise alkali control, reducing NaOH consumption, simultaneously solving the problem of salt crystallization blockage, and extending the equipment life. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model.
[0025] In the diagram: 1. Sulfur reactor; 2. Pre-cooling demister; 3. Defluorination tower; 4. Water washing tower; 5. Alkali washing tower; 6. Deep dryer; 7. Membrane separation tower; 8. Fan; 9. Tail gas treatment system; 10. Fluorine concentration monitor; 11. Fluorine-containing tail gas collection pipe; 12. Electric heating layer; 13. Condensation coil layer; 14. Demisting layer; 15. Adsorption bed; 16. Spray pipeline; 17. Online pH monitor; 18. Molecular sieve bed. Detailed Implementation
[0026] The present invention will be further described below with reference to specific embodiments.
[0027] like Figure 1 As shown, the fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model includes a sulfur reactor 1, a defluorination tower 3, a water washing tower 4, an alkaline washing tower 5, and a membrane separation tower 7. The bottom of the sulfur reactor 1 is connected to a fluorine-containing tail gas collection pipe 11. The outlet of the reaction gas of the sulfur reactor 1 is connected to the bottom inlet of the precooling demister 2. The top outlet of the precooling demister 2 is connected to the bottom inlet of the defluorination tower 3. The top outlet of the defluorination tower 3 is connected to the bottom inlet of the water washing tower 4. The top outlet of the water washing tower 4 is connected to the bottom inlet of the alkaline washing tower 5. The top outlet of the alkaline washing tower 5 is connected to the inlet of the deep dryer 6. The outlet of the deep dryer 6 is connected to the membrane separation tower 7. The enriched gas outlet of the membrane separation tower 7 is connected to a blower 8.
[0028] The tail gas outlet of the membrane separation tower 7 is connected to the tail gas treatment system 9.
[0029] An electric heating layer 12 is provided on the outer layer of the sulfur reactor 1.
[0030] The outer layer of the precooling demister 2 is provided with a condenser coil layer 13.
[0031] The pre-cooling demister 2 has a demister layer 14 inside.
[0032] The defluorination tower 3 is equipped with an adsorption bed 15 inside.
[0033] A fluoride concentration monitor 10 is installed on the outlet pipe of the defluorination tower 3.
[0034] The top of the water washing tower 4 is equipped with a spray pipe 16.
[0035] The alkaline washing tower 5 is equipped with an online pH monitor 17.
[0036] The deep dryer 6 is equipped with a molecular sieve bed 18.
[0037] The working steps of the fluorine and nitrogen anode defluorination and fluorine recovery device of this utility model are as follows:
[0038] (1) Fluorine and nitrogen anodes and other fluorine-containing tail gases enter sulfur reactor 1 through fluorine-containing tail gas collection pipe 11. Under the temperature control of electric heating layer 12, they react with sulfur to generate low-fluorine sulfides. The reaction gas enters pre-cooling demister 2, is cooled by condenser coil layer 13, and is removed by demister layer 14 to remove droplets and particulate matter.
[0039] (2) The gas enters from the bottom of the defluorination tower 3 and is further defluorinated by the adsorption bed 15; the fluorine concentration monitor 10 detects the purity of the outlet gas in real time.
[0040] (3) The gas enters the water washing tower 4, where it is sprayed with water through the top spray pipe 16 to wash and dissolve residual acidic substances. The gas then enters the alkali washing tower 5, where it reacts with the alkali solution to neutralize the acidic gas; the pH online monitor 17 regulates the concentration of the alkali solution. The gas then passes through the molecular sieve bed 18 of the deep dryer 6 to adsorb moisture, achieving the low dew point required for membrane separation.
[0041] (4) The dry gas enters the membrane separation tower 7. Due to the difference in permeation rate, sulfur hexafluoride is concentrated at the enrichment gas outlet and then pressurized by the blower 8 before being used in the sulfur hexafluoride production workshop. The low-fluorine tail gas after membrane separation enters the tail gas treatment system 9 and is discharged in compliance with standards after catalytic decomposition or adsorption.
[0042] This invention recovers fluorine gas generated during electrolysis and purification, reducing fluorine loss and minimizing environmental impact. The reaction product is transported to the sulfur hexafluoride production workshop via a sulfur reactor, increasing sulfur hexafluoride production and improving fluorine gas utilization while reducing waste. The tail gas treatment system avoids high-temperature damage caused by the exothermic reaction of fluorine gas with water, and pressure fluctuations are minimized, reducing the impact on the electrolysis process.
Claims
1. A device for fluorine and nitrogen anode defluorination and fluorine recovery, characterized in that: The system includes a sulfur reactor (1), a defluorination tower (3), a water washing tower (4), an alkaline washing tower (5), and a membrane separation tower (7). The bottom of the sulfur reactor (1) is connected to a fluorine-containing tail gas collection pipe (11). The outlet of the reaction gas of the sulfur reactor (1) is connected to the bottom inlet of the precooling demister (2). The top outlet of the precooling demister (2) is connected to the bottom inlet of the defluorination tower (3). The top outlet of the defluorination tower (3) is connected to the bottom inlet of the water washing tower (4). The top outlet of the water washing tower (4) is connected to the bottom inlet of the alkaline washing tower (5). The top outlet of the alkaline washing tower (5) is connected to the inlet of the deep dryer (6). The outlet of the deep dryer (6) is connected to the membrane separation tower (7). The enriched gas outlet of the membrane separation tower (7) is connected to a blower (8).
2. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 1, characterized in that: The tail gas outlet of the membrane separation tower (7) is connected to the tail gas treatment system (9).
3. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 1, characterized in that: An electric heating layer (12) is provided on the outer layer of the sulfur reactor (1).
4. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 3, characterized in that: The outer layer of the precooling demister (2) is provided with a condenser coil layer (13).
5. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 4, characterized in that: The precooling demister (2) has a demister layer (14) inside.
6. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 1, characterized in that: The defluorination tower (3) is equipped with an adsorption bed (15).
7. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 6, characterized in that: A fluorine concentration monitor (10) is installed on the outlet pipe of the defluorination tower (3).
8. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 1, characterized in that: The top of the water washing tower (4) is equipped with a spray pipe (16).
9. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 8, characterized in that: A pH online monitor (17) is installed on the main body of the alkaline washing tower (5).
10. The fluorine and nitrogen anode defluorination and fluorine recovery device according to claim 9, characterized in that: The deep dryer (6) is equipped with a molecular sieve bed (18).