A method for yellow phosphorus tail gas heat energy utilization and multi-pollutant purification
By combining a water washing tower, a fluidized bed gas boiler, a denitrification tower, a desulfurization and defluorination tower, and an electromagnetic purification system, the problems of low thermal energy utilization and high purification cost of yellow phosphorus tail gas are solved, achieving efficient, economical, and environmentally friendly purification of yellow phosphorus tail gas, and achieving ultra-low emissions and elimination of white plumes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YUNNAN YUNTIANHUA
- Filing Date
- 2026-04-21
- Publication Date
- 2026-06-19
Smart Images
Figure CN122230512A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of heat energy utilization and pollutant purification technology of yellow phosphorus tail gas, specifically relating to a method for heat energy utilization and purification of multiple pollutants from yellow phosphorus tail gas. Background Technology
[0002] Heat recovery and pollutant purification of yellow phosphorus tail gas are crucial steps in the yellow phosphorus production process. Currently, the effective utilization rate of yellow phosphorus tail gas in my country is less than 40%, mainly due to the difficulty of purifying the complex components in the gas. Yellow phosphorus tail gas contains a large amount of carbon monoxide (80-95%), along with small amounts of harmful impurities such as elemental phosphorus, phosphine, hydrogen sulfide, carbonyl sulfide, carbon disulfide, and hydrogen fluoride. Since the combustion of elemental phosphorus and phosphine in yellow phosphorus tail gas produces phosphoric acid, which is highly corrosive, some companies directly burn and discharge it after simple water washing and alkaline washing methods. Some companies connect multi-stage gas-fired boilers to recover the combustion heat of yellow phosphorus tail gas to produce steam, but a large amount of pollutants are still discharged without purification. A very small number of companies have used methods such as temperature and pressure swing adsorption and catalytic oxidation to deeply purify yellow phosphorus tail gas to obtain high-purity carbon monoxide, and then produce C1 chemical products. However, due to the high purification costs, the produced C1 chemical products are difficult to compete with those from coal chemical companies.
[0003] In 2021, yellow phosphorus production was listed as one of the first batch of "high-energy-consuming and high-polluting" industries. Energy conservation, carbon reduction, and cleaner production are urgently needed for yellow phosphorus enterprises, requiring the development of efficient, economical, and environmentally friendly new technologies to meet the national requirements for the green and low-carbon transformation of the yellow phosphorus industry. In view of this, this invention discloses a system for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants. This system can not only effectively recover the combustion heat of yellow phosphorus tail gas and reduce energy consumption in yellow phosphorus production, but also deeply purify various impurities in the yellow phosphorus tail gas, eliminate pollutant emissions, eliminate white plumes, and recover fluorine resources. Summary of the Invention
[0004] To address the shortcomings of the aforementioned technologies for heat recovery and pollutant purification of yellow phosphorus tail gas, this invention provides a method for utilizing the heat energy of yellow phosphorus tail gas and purifying multiple pollutants, thereby solving problems such as heat recovery from yellow phosphorus tail gas combustion, low-cost purification of phosphorus, sulfur, and fluorine pollutants, and elimination of white plumes.
[0005] The present invention discloses a method for the thermal energy utilization and multi-pollutant purification of yellow phosphorus tail gas. The purification system includes a water scrubbing tower, a fluidized bed gas-fired boiler, a denitrification tower, a desulfurization and defluorination tower, and an electromagnetic purification system. During operation, the furnace gas discharged from the yellow phosphorus electric furnace is passed into the water scrubbing tower to recover yellow phosphorus from the tail gas, resulting in yellow phosphorus tail gas. The yellow phosphorus tail gas exiting the water scrubbing tower enters the fluidized bed gas-fired boiler for combustion. Simultaneously, a dephosphorizing agent is injected into the fluidized bed gas-fired boiler to absorb residual yellow phosphorus and phosphine in the yellow phosphorus tail gas, preventing corrosion of the gas-fired boiler. The sulfides in the yellow phosphorus tail gas are burned and converted into sulfur dioxide (SO2) in the fluidized bed gas-fired boiler. Part of the nitrogen is oxidized by combustion to nitric oxide (NO). The exhaust gas after combustion contains impurities such as SO2, NO, and hydrogen fluoride (HF). The exhaust gas enters the denitrification tower, where NO is absorbed by the denitrification agent. The waste slurry discharged from the denitrification tower is used as a binder for dephosphorized phosphate rock powder discharged from the fluidized bed gas boiler, and is used as a raw material for the production of yellow phosphorus. The exhaust gas from the denitrification tower enters the desulfurization and defluorination tower, where SO2 and HF are absorbed by the desulfurization and defluorination agent. The flue gas discharged from the desulfurization and defluorination tower enters the electromagnetic purification system to deeply remove white plumes and various pollutants, and the purified exhaust gas is discharged into the atmosphere.
[0006] The yellow phosphorus tail gas contains 80-90% CO, and the phosphides include P4 and PH3, with P4 content ranging from 300-700 mg / m³. 3 The pH3 content is 500-9000 mg / m³. 3 Sulfides include H2S, COS, and CS2, with H2S content ranging from 800 to 6000 mg / m³. 3 COS content is 200-5000 mg / m³ 3 CS2 content is 15-80 mg / m³ 3 HF content is 300-500 mg / m³ 3 .
[0007] The dephosphorizing agent is low-grade phosphate rock produced during phosphate mining or phosphate rock powder produced during phosphate rock crushing.
[0008] In a fluidized bed gas-fired boiler, air is added during the combustion of yellow phosphorus tail gas; some nitrogen is converted into NO, and sulfides are converted into SO2 during combustion.
[0009] The denitrification agent is mud phosphorus from the water washing tower, and the mass ratio of P4 in the mud phosphorus to NO in the flue gas is 5-10:1.
[0010] The desulfurization and defluorination agent is a yellow phosphorus slag slurry, which is prepared by mixing yellow phosphorus slag and water, with a solid content of 5-50 wt%. The yellow phosphorus slag comes from the waste residue produced by the yellow phosphorus electric furnace.
[0011] The yellow phosphorus tail gas discharged from the defluorination tower contains trace amounts of sulfur, phosphorus, and fluorine pollutants, as well as white plumes. After purification by the electromagnetic purification device, the content of CO, phosphorus (as P2O5), SO2, fluorine (as F), and particulate matter in the purified tail gas is ≤5 mg / m³. 3 ， No white plumes.
[0012] Advantages and technical effects of this invention: The dephosphorization principle of phosphate rock powder dephosphorizing agent is to utilize the magnesium calcium carbonate, calcium fluorophosphate and other sesquioxides in phosphate rock powder to produce P4O from the combustion of P4 and PH3 in yellow phosphorus tail gas. 10 It reacts with H3PO4 to produce calcium phosphate, calcium pyrophosphate, calcium iron phosphate, and other substances. The principle of SO2 removal using a desulfurizing agent prepared from yellow phosphorus slag and water is that SO2 dissolves in the slurry to form sulfuric acid, which then reacts with the silicon and calcium compounds in the yellow phosphorus slag to produce calcium sulfate dihydrate (CaSO4•2H2O) and silicon dioxide (SiO2). HF removal utilizes the reaction of SiO2 generated after desulfurization of the yellow phosphorus slag with HF to produce silicon tetrafluoride (SiF4). The principle of NO purification using a denitrifying agent prepared from mud phosphorus and water is that NO is oxidized by ozone (O3), oxygen atoms (O), and hydroxyl radicals (•OH) induced by P4 in the mud phosphorus to become water-soluble high-valence nitrogen oxides, which then react with nitric acid and calcium salts to produce calcium nitrate. Electromagnetic purification of pollutants utilizes electromagnetic devices to generate different magnetic fields, magnetizing and agglomerating pollutants into large particles. When the gravity of the agglomerates exceeds the magnetic force, the agglomerated pollutants are removed, thus achieving the purpose of purifying pollutants and eliminating white plumes.
[0013] This invention comprehensively utilizes various energy sources in the yellow phosphorus production system, which can greatly reduce the cost of treating yellow phosphorus tail gas pollutants, recover the combustion heat and fluorine resources of yellow phosphorus tail gas, and ensure that the pollutants in the purified tail gas meet ultra-low emission standards. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the process flow for the utilization of yellow phosphorus tail gas thermal energy and the purification of multiple pollutants in this invention. Detailed Implementation
[0015] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. However, the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the methods in the embodiments are conventional methods or detection methods, and unless otherwise specified, the reagents used are conventional reagents or reagents prepared according to conventional methods. The system used in the method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants in the following embodiments includes a water scrubbing tower, a fluidized bed gas boiler, a denitrification tower, a desulfurization and defluorination tower, and an electromagnetic purification system; wherein the tail gas outlet of the yellow phosphorus electric furnace is connected to the inlet of the water scrubbing tower, the outlet of the water scrubbing tower is connected to the inlet of the fluidized bed gas boiler, the outlet of the fluidized bed gas boiler is connected to the inlet of the denitrification tower, the outlet of the denitrification tower is connected to the inlet of the desulfurization and defluorination tower, and the outlet of the desulfurization and defluorination tower is connected to the inlet of the electromagnetic purification device; like Figure 1 As shown, the furnace gas discharged from the yellow phosphorus electric furnace is passed into a water scrubbing tower to recover the yellow phosphorus in the tail gas, resulting in yellow phosphorus tail gas. The yellow phosphorus tail gas from the water scrubbing tower enters a fluidized bed gas-fired boiler for combustion. Simultaneously, a dephosphorizing agent is injected into the fluidized bed gas-fired boiler to absorb the residual yellow phosphorus and phosphine in the yellow phosphorus tail gas, preventing corrosion of the gas-fired boiler. The sulfides in the yellow phosphorus tail gas are burned and converted into sulfur dioxide (SO2) in the fluidized bed gas-fired boiler, and some nitrogen is oxidized and converted into nitric oxide (NO). The tail gas after combustion... Gases containing impurities such as SO2, NO, and hydrogen fluoride (HF) enter the denitrification tower, where NO is absorbed by the denitrification agent. The waste slurry discharged from the denitrification tower is used as a binder for dephosphorized phosphate rock powder discharged from the fluidized bed gas boiler, and is used to prepare raw materials for yellow phosphorus production. The tail gas from the denitrification tower enters the desulfurization and defluorination tower, where SO2 and HF are absorbed by the desulfurization and defluorination agent. The flue gas discharged from the desulfurization and defluorination tower enters the electromagnetic purification system, where white plumes and various pollutants are deeply removed, and purified tail gas is discharged into the atmosphere. Example 1
[0016] After being washed in a water scrubbing tower, the yellow phosphorus tail gas from the yellow phosphorus electric furnace has a CO content of 80% and a P4 content of 300 mg / m³. 3 The pH3 content is 500 mg / m³. 3 H2S content is 800 mg / m³ 3 COS content is 200mg / m³ 3 The CS2 content is 15 mg / m³. 3 HF content is 300 mg / m³ 3 The yellow phosphorus tail gas is fed into a fluidized bed gas-fired boiler for combustion. Low-grade phosphate rock powder, generated during phosphate mining, is injected as a dephosphorizing agent to purify and remove P4 and PH3. The phosphorus content (calculated as P2O5) in the tail gas discharged from the fluidized bed gas-fired boiler is 50 mg / m³. 3 The SO2 content is 1744 mg / m³ 3 The HF content is 300 mg / m³. 3 CO content is 20 mg / m³ 3 The NO content is 200 mg / m³ 3Finally, the exhaust gas sequentially enters the denitrification tower and the desulfurization and defluorination tower. The mass ratio of P4 in the mud phosphorus denitrification agent to NO in the flue gas is controlled at 5:1, and the solid content of the yellow phosphorus slag desulfurization and defluorination agent is 5wt%. The phosphorus content (calculated as P2O5) in the exhaust gas discharged from the desulfurization and defluorination tower is 50mg / m³. 3 SO2 content is 40 mg / m³ 3 CO content is 20 mg / m³ 3 The NO content is 50 mg / m³. 3 The fluorine content is 20 mg / m³. 3 The phosphorus content (calculated as P2O5) is 50 mg / m³. 3 After being purified by an electromagnetic purification device, the CO content in the purified exhaust gas was 5 mg / m³. 3 Phosphorus (calculated as P2O5) content is 3 mg / m³ 3 SO2 content is 5 mg / m³ 3 The fluorine content (as F) is 2 mg / m³. 3 The particulate matter concentration was 5 mg / m³. 3 No white plumes were observed. Example 2
[0017] After being washed in a water scrubbing tower, the yellow phosphorus tail gas from the yellow phosphorus electric furnace has a CO content of 88% and a P4 content of 500 mg / m³. 3 The pH3 content is 2000 mg / m³. 3 H2S content is 3000 mg / m³ 3 COS content is 2000 mg / m³ 3 The CS2 content is 40 mg / m³. 3 HF content is 400 mg / m³ 3 The yellow phosphorus tail gas is fed into a fluidized bed gas-fired boiler for combustion. Phosphate powder produced during the phosphate rock crushing process is injected as a dephosphorizing agent to purify and remove P4 and PH3. The phosphorus content (calculated as P2O5) in the tail gas discharged from the fluidized bed gas-fired boiler is 60 mg / m³. 3 The SO2 content is 7848 mg / m³ 3 The HF content is 400 mg / m³. 3 CO content is 30 mg / m³ 3 The NO content is 500 mg / m³ 3 Finally, the exhaust gas sequentially enters the denitrification tower and the desulfurization and defluorination tower. The mass ratio of P4 in the mud phosphorus denitrification agent to NO in the flue gas is controlled at 7:1, and the solid content of the yellow phosphorus slag desulfurization and defluorination agent is 20wt%. The phosphorus content (calculated as P2O5) in the exhaust gas discharged from the desulfurization and defluorination tower is 40mg / m³. 3 The SO2 content is 35 mg / m³ 3 CO content is 30 mg / m³ 3The NO content is 50 mg / m³. 3 The fluorine content is 18 mg / m³. 3 The phosphorus content (calculated as P2O5) is 50 mg / m³. 3 After being purified by an electromagnetic purification device, the CO content in the purified exhaust gas was 4 mg / m³. 3 The phosphorus content (calculated as P2O5) is 4 mg / m³. 3 SO2 content is 4 mg / m³ 3 The fluorine content (as F) is 3 mg / m³. 3 The particulate matter concentration was 4 mg / m³. 3 No white plumes were observed. Example 3
[0018] After being washed in a water scrubbing tower, the yellow phosphorus tail gas from the yellow phosphorus electric furnace has a CO content of 95% and a P4 content of 700 mg / m³. 3 The pH3 content is 9000 mg / m³. 3 H2S content is 6000 mg / m³ 3 COS content is 5000 mg / m³ 3 The CS2 content is 80 mg / m³. 3 HF content is 500 mg / m³ 3 The yellow phosphorus tail gas is fed into a fluidized bed gas-fired boiler for combustion. Low-grade phosphate rock powder, generated during phosphate mining, is injected as a dephosphorizing agent to purify and remove P4 and PH3. The phosphorus content (calculated as P2O5) in the tail gas discharged from the fluidized bed gas-fired boiler is 100 mg / m³. 3 The SO2 content was 16762 mg / m³. 3 The HF content is 500 mg / m³. 3 The CO content is 15 mg / m³ 3 The NO content is 800 mg / m³ 3 Finally, the exhaust gas sequentially enters the denitrification tower and the desulfurization and defluorination tower. The mass ratio of P4 in the mud phosphorus denitrification agent to NO in the flue gas is controlled at 10:1, and the solid content of the yellow phosphorus slag desulfurization and defluorination agent is 50wt%. The phosphorus content (calculated as P2O5) in the exhaust gas discharged from the desulfurization and defluorination tower is 60mg / m³. 3 SO2 content is 30 mg / m³ 3 The CO content is 15 mg / m³ 3 The NO content is 45 mg / m³. 3 The fluorine content is 15 mg / m³. 3 The phosphorus content (calculated as P2O5) is 60 mg / m³. 3 After being purified by an electromagnetic purification device, the CO content in the purified exhaust gas was 3 mg / m³. 3 The phosphorus content (calculated as P2O5) is 2 mg / m³.3 SO2 content is 3 mg / m³ 3 The fluorine content (as F) is 1 mg / m³. 3 The particulate matter concentration was 3 mg / m³. 3 No white plumes were observed.
[0019] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants, characterized in that: The furnace gas discharged from the yellow phosphorus electric furnace is fed into a water scrubbing tower to recover yellow phosphorus from the tail gas, resulting in yellow phosphorus tail gas. The yellow phosphorus tail gas from the water scrubbing tower enters a fluidized bed gas-fired boiler for combustion. Simultaneously, a dephosphorizing agent is injected into the fluidized bed gas-fired boiler to absorb the residual yellow phosphorus and phosphine in the yellow phosphorus tail gas, preventing corrosion of the gas-fired boiler. The sulfides in the yellow phosphorus tail gas are burned and converted into sulfur dioxide in the fluidized bed gas-fired boiler, and some nitrogen is oxidized into nitric oxide. The tail gas after combustion enters a denitrification tower, where NO is absorbed by a denitrification agent. The waste slurry discharged from the denitrification tower is used as a binder for the dephosphorized phosphate rock powder discharged from the fluidized bed gas-fired boiler, preparing raw materials for yellow phosphorus production. The tail gas from the denitrification tower enters a desulfurization and defluorination tower, where SO2 and HF are absorbed by a desulfurization and defluorination agent. The flue gas discharged from the desulfurization and defluorination tower enters an electromagnetic purification system to deeply remove white plumes and various pollutants, resulting in purified tail gas that is discharged into the atmosphere.
2. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: The CO content in yellow phosphorus tail gas is 80-95%, and the phosphides include P4 and PH3, with the P4 content being 300-700 mg / m³. 3 The pH3 content is 500-9000 mg / m³. 3 Sulfides include H2S, COS, and CS2, with H2S content ranging from 800 to 6000 mg / m³. 3 COS content is 200-5000 mg / m³ 3 CS2 content is 15-80 mg / m³ 3 HF content is 300-500 mg / m³ 3 .
3. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: Dephosphorizing agent is low-grade phosphate rock powder produced during phosphate mining or phosphate rock crushing.
4. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: Air is added during the combustion of yellow phosphorus tail gas in a fluidized bed gas-fired boiler.
5. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: The denitrification agent is mud phosphorus from the water washing tower, and the mass ratio of P4 in the mud phosphorus to NO in the flue gas is 5-10:
1.
6. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: The desulfurization and defluorination agent is yellow phosphorus slag slurry, which is prepared by mixing yellow phosphorus slag and water, with a solid content of 5-50 wt%. The yellow phosphorus slag comes from the waste residue produced by yellow phosphorus electric furnace.
7. The method for utilizing the thermal energy of yellow phosphorus tail gas and purifying multiple pollutants according to claim 1, characterized in that: The yellow phosphorus tail gas discharged from the defluorination tower still contains trace amounts of sulfur, phosphorus, and fluorine pollutants, as well as white plumes. After purification by the electromagnetic purification device, the content of CO, phosphorus (calculated as P2O5), SO2, fluorine, and particulate matter in the purified tail gas is all ≤5 mg / m³. 3 No white plumes were observed.