Liquid desulfurizer based on alkali production mother liquor and all-vanadium redox flow battery waste liquor and preparation method of liquid desulfurizer

Abstract

The invention relates to the technical field of desulfurizing agents, in particular to a liquid desulfurizing agent based on alkali production mother liquor and all-vanadium redox flow battery waste liquor and a preparation method of the liquid desulfurizing agent. The invention discloses a liquid desulfurizer based on alkali-making mother liquor and all-vanadium redox flow battery waste liquor. The liquid desulfurizer is prepared from a component A and a component B according to the mass ratio of (65-95): (5-35), the component A is prepared from the following raw materials in percentage by mass: 30 to 70 weight percent of alkali production mother liquor, 20 to 50 weight percent of glycerin water, 3 to 10 weight percent of polyhydric alcohols, 2 to 8 weight percent of sodium citrate, 0.5 to 3 weight percent of cyclohexanone peroxide and 1 to 5 weight percent of petroleum ether; and the component B comprises an all-vanadium redox flow battery waste liquid pretreatment liquid. The method has the advantages that the waste liquid is synergistically utilized, the vanadium ions are used for catalytic oxidation of low-valence sulfur-containing components, and the alkali absorption characteristic of the alkali-making mother liquor is combined, so that the efficient and low-cost desulfurization process is realized. Meanwhile, waste liquid resource utilization is achieved, the desulfurization cost is reduced, and the method is suitable for the field of industrial flue gas treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurizing agents, and particularly to a liquid desulfurizing agent based on soda-making mother liquor and spent liquid of a vanadium redox flow battery and a preparation method thereof. Background Art

[0002] The necessary raw materials in cement production are mainly limestone and coal, and the sulfur content in limestone and coal directly affects the emission index of sulfur dioxide (SO₂) of cement enterprises. Under the high demand for environmental protection, the concentration requirement of sulfur dioxide in cement kiln flue gas is getting lower and lower, and the desulfurization requirement for sulfur dioxide (SO₂) in the flue gas discharged by each cement enterprise is also getting higher and higher, that is, the sulfur dioxide (SO₂) in the discharged flue gas can be reduced through desulfurization treatment. At present, there are the following three traditional desulfurization methods: limestone-gypsum method, wet absorption method, and dry adsorption method.

[0003] Traditional desulfurization technologies such as the limestone-gypsum method have the following defects: first, a large amount of limestone needs to be consumed, and the by-product gypsum has low economic value and high cost; second, Cl in the wet desulfurization system - enrichment accelerates equipment corrosion; third, it is difficult to treat the waste residue, and the gypsum accumulation occupies land resources and is likely to cause soil salinization.

[0004] While traditional desulfurization technologies such as wet absorption (such as sulfonamide method) and dry adsorption (activated carbon, iron oxide) have problems such as high cost, difficult regeneration, frequent replacement increasing operation and maintenance costs, and being prone to secondary pollution. Summary of the Invention

[0005] In order to solve the defects of traditional desulfurization methods, the present invention provides a liquid desulfurizing agent based on soda-making mother liquor and spent liquid of a vanadium redox flow battery and a preparation method thereof. In the present invention, a mother liquor generated during the preparation of baking soda by the double decomposition method of industrial salt (NaCl) and a product after pretreatment of a spent vanadium battery electrolyte are used to prepare a liquid desulfurizing agent, and vanadium ions are used to catalytically oxidize sulfides, combined with the alkaline absorption characteristics of the soda-making mother liquor, to achieve an efficient and low-cost desulfurization process. At the same time, the resource utilization of the waste liquid is realized and the desulfurization cost is reduced.

[0006] A liquid desulfurizing agent based on soda-making mother liquor and spent liquid of a vanadium redox flow battery provided by the present invention is achieved through the following technical solutions:

[0007] A liquid desulfurizing agent based on soda-making mother liquor and spent liquid of a vanadium redox flow battery is compounded from component A and component B in a mass ratio of (65-95):(5-35); component A is made from raw materials with the following mass percentages: 30-70 wt% of soda-making mother liquor, 20-50 wt% of glycerol water, 3-10 wt% of polyol, 2-8 wt% of sodium citrate, 0.5-3 wt% of cyclohexanone peroxide, 1-5 wt% of petroleum ether; component B includes a pretreatment liquid of spent liquid of a vanadium redox flow battery.

[0008] The present invention realizes an efficient and low-cost desulfurization process by synergistically utilizing waste liquid, catalyzing and oxidizing components containing low-valence sulfur with vanadium ions, and combining with the alkaline absorption characteristics of soda-making mother liquor. At the same time, it realizes the resource utilization of waste liquid, reduces the desulfurization cost, and is applicable to the field of industrial flue gas treatment.

[0009] Preferably, the soda-making mother liquor in the component A is a by-product of the ammonia-soda method, the combined soda-making method, or the industrial salt double decomposition soda-making process, and the pH value of the soda-making mother liquor in the component A is 7-10.

[0010] More preferably, the soda-making mother liquor in the component A is the mother liquor generated during the preparation of sodium bicarbonate by the industrial salt NaCl double decomposition method, and the pH value of the soda-making mother liquor in the component A is 7-10.

[0011] Preferably, the soda-making mother liquor in the component A is made from the following raw materials by mass percentage: 10-26.5 wt% of NaCl, 5-25 wt% of NH4Cl, 5-10 wt% of NH4HCO3, 5-10 wt% of Na2CO3, 3-8 wt% of NaHCO3, and the balance is water.

[0012] Preferably, the waste liquid pretreatment liquid of the all-vanadium redox flow battery is an alkaline mixed liquid formed after pretreatment of the strongly acidic waste liquid formed after the failure of the all-vanadium redox flow battery electrolyte.

[0013] Preferably, the total vanadium concentration in the strongly acidic waste liquid formed after the failure of the all-vanadium redox flow battery electrolyte is 1-2.5 mol / L, the valence states of vanadium ions are V 2+ 、V 3+ 、V 4+ 、V 5+ mixed valence states, the sulfate ion concentration is 1-5 mol / L, and the impurity ions containing less than 0.01 mol / L of Fe 3+ 、Al 3+ 、Ca 2+ The pH value of the strongly acidic waste liquid formed after the failure of the all-vanadium redox flow battery electrolyte is less than 2.0.

[0014] Preferably, the preparation method of the waste liquid pretreatment liquid of the all-vanadium redox flow battery is as follows:

[0015] Step 1, solution homogenization: Stir and mix the strongly acidic waste liquids formed after the failure of multiple batches of all-vanadium redox flow battery electrolytes in an acid-resistant storage tank to make the strongly acidic waste liquids formed after the failure of multiple batches of all-vanadium redox flow battery electrolytes be mixed and homogenized to obtain a mixed waste liquid, ensuring the stable composition of the mixed waste liquid;

[0016] Step 2, primary filtration: Filter the mixed waste liquid, and the precision of the filter cloth used is <10 microns;

[0017] Step 3, neutralization adjustment: Spray a pH regulator into the mixed waste liquid by means of multi-stage segmented atomization. The pH regulator is any one of a sodium carbonate solution with a mass concentration of 8-10%, a sodium bicarbonate solution with a mass concentration of 6-8%, an ammonia water with a mass concentration of 5-20%, and a sodium hydroxide solution with a mass concentration of 6-12%. Adjust the pH value to 3-4 in the first stage; adjust the pH to 6-7 in the second stage;

[0018] Step 4, stabilization treatment: Add a stabilizer in a ratio of 1:1 to vanadium ions. The stabilizer includes any one of a disodium EDTA solution, a sodium citrate solution, a sodium hexametaphosphate solution, and a citric acid solution with a mass concentration of 0.1-0.5%, ensuring that the vanadium ions in the solution are stable and do not precipitate, and at the same time finely adjust the pH value of the solution to 7-9;

[0019] Step 5, secondary filtration: Ultrafilter to remove the colloids and micro-precipitates generated during the neutralization adjustment and stabilization treatment processes, and the finished product of the pre-treated liquid of the all-vanadium redox flow battery waste liquid can be obtained.

[0020] The preparation method of the pre-treated liquid of the all-vanadium redox flow battery waste liquid provided in the present invention is relatively simple, the operation difficulty is relatively low, it is convenient to realize industrial batch production, and the production cost of the liquid desulfurizer is reduced.

[0021] Preferably, the glycerol concentration in the glycerol water is 30%-50%.

[0022] Preferably, the polyol is at least one of propylene glycol, glycerol, butanediol, and sorbitol.

[0023] The preparation method of a liquid desulfurizer based on soda-making mother liquor and all-vanadium redox flow battery waste liquid provided by the present invention is realized through the following technical solutions:

[0024] A preparation method of a liquid desulfurizer based on soda-making mother liquor and all-vanadium redox flow battery waste liquid is as follows:

[0025] Preparation of component A: First, mix the soda-making mother liquor and sodium citrate in proportion, stir evenly, and react at a constant temperature for 0.5-2 h to obtain a mixed solution A. Then, mix glycerol water, polyol, and petroleum ether in proportion and stir evenly. Under the water bath condition, control the solution temperature to remain at 20-25 °C. Add cyclohexanone peroxide to the solution while stirring. After the addition of cyclohexanone peroxide is completed, continue to stir for 20-40 min to obtain a mixed solution B. Finally, add the mixed solution B to the mixed solution A according to the ratio and stir for 20-40 min to obtain component A;

[0026] Preparation of component B of the pre-treated liquid of the all-vanadium redox flow battery waste liquid;

[0027] During use, components A and B are added separately for use to remove sulfur dioxide in the flue gas.

[0028] The preparation method of the liquid desulfurizer based on soda-making mother liquor and spent vanadium redox flow battery waste liquid provided in the present invention is relatively simple, with low operation difficulty, facilitating industrial production and reducing the production cost of the liquid desulfurizer.

[0029] Preferably, the preparation of the pretreatment liquid of component B, the spent vanadium redox flow battery waste liquid, is as follows:

[0030] Step 1, solution homogenization: Stir and mix the strongly acidic waste liquid formed after the failure of multi-batch vanadium redox flow battery electrolytes in an acid-resistant storage tank to obtain a mixed waste liquid by mixing and homogenizing the strongly acidic waste liquid formed after the failure of multi-batch vanadium redox flow battery electrolytes, ensuring the stable composition of the mixed waste liquid and monitoring the pH value before and after mixing;

[0031] Step 2, primary filtration: Filter the mixed waste liquid, and the precision of the filter cloth used is <10 microns;

[0032] Step 3, neutralization adjustment: Spray the pH regulator into the mixed waste liquid by means of multi-stage segmented atomization spraying. The pH regulator is any one of a sodium carbonate solution with a mass concentration of 8-10%, a sodium bicarbonate solution with a mass concentration of 6-8%, an ammonia water solution with a mass concentration of 5-20%, and a sodium hydroxide solution with a mass concentration of 6-12%. Adjust the pH value to 3-4 in the first stage; adjust the pH to 6-7 in the second stage;

[0033] Step 4, stabilization treatment: Add a stabilizer in a mass ratio of 1:1 to the vanadium ions. The stabilizer includes any one of a disodium EDTA solution, a sodium citrate solution, a sodium hexametaphosphate solution, and a citric acid solution with a mass concentration of 0.1-0.5%, ensuring the stability of vanadium ions in the solution without precipitation, and at the same time finely adjusting the pH value of the solution to 7-9;

[0034] Step 5, secondary filtration: Ultrafilter to remove the colloids and micro-precipitates generated during the neutralization adjustment and stabilization treatment processes to obtain the finished product of the pretreatment liquid of the spent vanadium redox flow battery waste liquid.

[0035] When the above-prepared liquid desulfurizer based on soda-making mother liquor and spent vanadium redox flow battery waste liquid is used, components A and B are added and used in a separate feeding manner, and the feeding position is at the cyclone of the secondary preheater or the outlet of the high-temperature fan at the kiln tail, realizing an efficient and low-cost desulfurization process with a desulfurization efficiency of over 90%.

[0036] In summary, the present invention has the following advantages:

[0037] 1. In the present invention, a liquid desulfurizer is prepared from the mother liquor generated during the preparation of baking soda by the double decomposition method of industrial salt NaCl and the product after the pretreatment vanadium battery electrolyte fails. Vanadium ions are used to catalyze the oxidation of sulfur components with low valence, combined with the alkaline absorption characteristics of the mother liquor for soda production, to efficiently remove sulfur dioxide in the flue gas of cement plants, forming a desulfurization system with high oxidation-reduction activity, realizing an efficient and low-cost desulfurization process. The desulfurization efficiency reaches more than 90%, and at the same time, the recycling of waste liquid is realized, and the desulfurization cost is reduced.

[0038] 2. The preparation method of the pretreatment liquid for the waste liquid of the all-vanadium redox flow battery provided in the present invention is relatively simple, with relatively low operation difficulty, facilitating industrial batch production and reducing the production cost of the liquid desulfurizer.

[0039] 3. The preparation method of the liquid desulfurizer based on the mother liquor for soda production and the waste liquid of the all-vanadium redox flow battery provided in the present invention is relatively simple, with low operation difficulty, facilitating industrial production and reducing the production cost of the desulfurizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is the initial desulfurization efficiency curve graph of the desulfurizer in Examples 1-7 and Comparative Examples 1-3.

[0041] Figure 2 It is the desulfurization efficiency curve graph of the desulfurizer after adsorption for 1 h in Examples 1-7 and Comparative Examples 1-3.

[0042] Figure 3 It is the curve graph of the difference between the initial desulfurization efficiency and the desulfurization efficiency after adsorption for 1 h of the desulfurizer in Examples 1-7 and Comparative Examples 1-3.

[0043] Figure 4 It is the average desulfurization efficiency curve graph of the desulfurizer after adsorption for 1 h in Examples 1-7 and Comparative Examples 1-3. DETAILED DESCRIPTION OF THE INVENTION

[0044] In order to further understand the creativity and technological progress of the present invention, the preferred implementation schemes of the present invention will be described in detail below in combination with examples and comparative examples.

[0045] EXAMPLES

[0046] A liquid desulfurizer based on the mother liquor for soda production and the waste liquid of the all-vanadium redox flow battery is prepared by compounding component A and component B in a mass ratio of (65-95):(5-35).

[0047] The A component is made of raw materials with the following mass percentages: 30 - 70 wt% of alkali-making mother liquor, 20 - 50 wt% of glycerol water, 3 - 10 wt% of polyol, 2 - 8 wt% of sodium citrate, 0.5 - 3 wt% of cyclohexanone peroxide, and 1 - 5 wt% of petroleum ether. Among them, the alkali-making mother liquor in the A component is a by-product of the ammonia-soda method, the combined soda-making method, or the industrial salt double decomposition alkali-making process. The pH value of the alkali-making mother liquor in the A component is 7 - 10. Preferably, the alkali-making mother liquor is the mother liquor generated during the preparation of baking soda by the industrial salt NaCl double decomposition method.

[0048] Specifically, the alkali-making mother liquor in the A component is made of raw materials with the following mass percentages: 10 - 26.5 wt% of NaCl, 5 - 25 wt% of NH4Cl, 5 - 10 wt% of NH4HCO3, 5 - 10 wt% of Na2CO3, 3 - 8 wt% of NaHCO3, and the balance is water.

[0049] The glycerol concentration in the glycerol water is 30% - 50%, and the glycerol water is composed of glycerol and water.

[0050] The polyol is at least one of propylene glycol, glycerol, butanediol, and sorbitol.

[0051] The B component includes the pretreatment liquid of the spent vanadium redox flow battery waste liquid. The pretreatment liquid of the spent vanadium redox flow battery waste liquid is an alkaline mixed liquid formed after pretreatment of the strongly acidic waste liquid formed after the vanadium redox flow battery electrolyte fails. The total vanadium concentration in the strongly acidic waste liquid formed after the vanadium redox flow battery electrolyte fails is 1 - 2.5 mol / L, and the valence states of vanadium ions are V 2+ 、V 3+ 、V 4+ 、V 5+ mixed valence states, the sulfate ion concentration is 1 - 5 mol / L, and it contains impurity ions of less than 0.01 mol / L of Fe 3+ 、Al 3+ 、Ca 2+ and the pH value of the strongly acidic waste liquid formed after the vanadium redox flow battery electrolyte fails is less than 2.0.

[0052] A preparation method of a liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid is as follows:

[0053] Preparation of the A component: First, mix the alkali-making mother liquor and sodium citrate in proportion, stir evenly, and react at a constant temperature for 0.5 - 2 h to obtain the mixed liquid A. Then, mix the glycerol water, polyol, and petroleum ether in proportion and stir evenly. Under the water bath condition, control the solution temperature to be maintained at 20 - 25 °C. Add cyclohexanone peroxide to the solution while stirring. After the addition of cyclohexanone peroxide is completed, continue to stir for 20 - 40 min to obtain the mixed liquid B. Finally, add the mixed liquid B to the mixed liquid A according to the ratio and stir for 20 - 40 min to obtain the A component;

[0054] The preparation of the pretreatment liquid for the waste liquid of the B-component all-vanadium redox flow battery is as follows:

[0055] Step 1, solution homogenization: Stir and mix the strongly acidic waste liquid formed after the failure of the multi-batch all-vanadium redox flow battery electrolyte in an acid-resistant storage tank to make the strongly acidic waste liquid formed after the failure of the multi-batch all-vanadium redox flow battery electrolyte mixed and homogenized to obtain a mixed waste liquid, ensure the stable composition of the mixed waste liquid, and monitor the pH value before and after mixing;

[0056] Step 2, primary filtration: Filter the mixed waste liquid, and the precision of the filter cloth used is <10 microns;

[0057] Step 3, neutralization adjustment: Atomize and spray a pH regulator into the mixed waste liquid by using a multi-stage segmented atomization spraying method. The pH regulator is any one of a sodium carbonate solution with a mass concentration of 8-10%, a sodium bicarbonate solution with a mass concentration of 6-8%, an ammonia water with a mass concentration of 5-20%, and a sodium hydroxide solution with a mass concentration of 6-12%. Adjust the pH value to 3-4 in the first stage; adjust the pH to 6-7 in the second stage;

[0058] Step 4, stabilization treatment: Add a stabilizer in a ratio of 1:1 to vanadium ions. The stabilizer includes any one of an EDTA disodium solution, a sodium citrate solution, a sodium hexametaphosphate solution, and a citric acid solution with a mass concentration of 0.1-0.5%, ensure that the vanadium ions in the solution are stable and do not precipitate, and at the same time finely adjust the pH value of the solution to 7-9;

[0059] Step 5, secondary filtration: Ultrafilter to remove the colloid and micro-precipitation generated during the neutralization adjustment and stabilization treatment processes, and the finished product of the pretreatment liquid for the waste liquid of the all-vanadium redox flow battery can be obtained;

[0060] During use, the A and B components are added and used in a separate feeding manner to remove sulfur dioxide from the flue gas. Specifically, when the above-prepared liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is used, the A and B components are added and used in a separate feeding manner, and the feeding position is at the cyclone of the secondary preheater or at the outlet of the high-temperature fan at the kiln tail, realizing an efficient and low-cost desulfurization process, and the desulfurization efficiency is over 90%.

[0061] Example 1:

[0062] A liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from the A component and the B component in a mass ratio of 95:5. The A component is made of the following raw materials by mass percentage: 70 wt% of the alkali-making mother liquor, 15 wt% of glycerol water (the glycerol concentration in the glycerol water is 35%), 5 wt% of 1,3-butanediol, 6 wt% of sodium citrate, 1 wt% of cyclohexanone peroxide, and 3 wt% of petroleum ether.

[0063] Component B is the pretreatment liquid for the waste liquid of the all-vanadium redox flow battery.

[0064] The soda-making mother liquor is the mother liquor generated during the preparation of baking soda by the double decomposition method of industrial salt NaCl. Specifically, the soda-making mother liquor in Component A is composed of 18.25 wt% NaCl, 7.64 wt% NH4Cl, 6.47 wt% NH4HCO3, 4.12 wt% Na2CO3, 3.48 wt% NaHCO3, and the balance is water. The measured pH value is 8.14.

[0065] A preparation method of a liquid desulfurizer based on the soda-making mother liquor and the waste liquid of the all-vanadium redox flow battery is as follows:

[0066] Preparation of Component A: First, mix the soda-making mother liquor and sodium citrate in proportion, stir evenly, and react at a constant temperature for 60 min to obtain a mixed solution A. Then, mix glycerol water, polyol, and petroleum ether in proportion and stir evenly. Under the water bath condition, control the solution temperature to remain at 25 °C. Slowly add cyclohexanone peroxide to the solution at a dropping rate of 1 ml / 60 s, stirring while adding, with a rotation speed of 120 r / min. After the addition of cyclohexanone peroxide is completed, continue to stir for 0.5 h to obtain a mixed solution B. Finally, add the mixed solution B to the mixed solution A according to the ratio and stir for 0.5 h to obtain Component A;

[0067] Component B is the pretreatment liquid for the waste liquid of the all-vanadium redox flow battery, and its preparation is as follows:

[0068] Step 1, solution homogenization: Stir and mix the strongly acidic waste liquid formed after the failure of multiple batches of all-vanadium redox flow battery electrolytes in an acid-resistant storage tank to make the strongly acidic waste liquid formed after the failure of multiple batches of all-vanadium redox flow battery electrolytes mixed and homogenized to obtain a mixed waste liquid, ensuring the stability of the composition of the mixed waste liquid. The total vanadium concentration in the obtained mixed waste liquid is 1.46 mol / L, and the valence states of vanadium ions are V 2+ 、V 3+ 、V 4+ 、V 5+ mixed valence states. Specifically, the concentration of V 2+ is 0.051 g / L (V 2+ has the strongest reducibility and extremely small stock), the concentration of V3 + is 0.407 g / L, the concentration of V 4+ is 18.593 g / L, the concentration of V 5+ is 55.321 g / L, the concentration of sulfate ion contained is 321.29 g / L, containing 0.12 g / L of Fe 3+ 、0.21 g / L of Al 3+ 、0.24 g / L of Ca 2+ , and the pH value is 1.3;

[0069] Step 2, primary filtration: Filter the mixed waste liquid using a 2000-mesh filter cloth with a precision of 6.5 microns.

[0070] Step 3, neutralization adjustment: Atomize and spray a pH regulator into the mixed waste liquid using a multi-stage segmented atomization spraying method. The pH regulator is a 10% sodium carbonate solution by mass concentration. In the first stage, atomize and spray the 10% sodium carbonate solution into the solution to adjust the pH value to 3.8. In the second stage, atomize and spray the 10% sodium carbonate solution to adjust the pH to 7.0.

[0071] Step 4, stabilization treatment: Add a stabilizer in a mass ratio of 1:1 to the vanadium ions. The stabilizer is a 0.4% disodium EDTA solution by mass concentration. The content of disodium EDTA added to the solution is 74.372 g / L to ensure the stability of vanadium ions in the solution without precipitation. Add 5 wt% calcium bicarbonate to finely adjust the pH value of the solution to 8.1.

[0072] Step 5, secondary filtration: Use an ultrafiltration system to ultrafilter the solution in Step 4 to remove the colloids and micro-precipitates generated during the neutralization adjustment and stabilization treatment processes, obtaining the finished product of the pre-treated waste liquid of the all-vanadium redox flow battery.

[0073] During use, components A and B are added and used in a separate feeding manner to remove sulfur dioxide from the flue gas.

[0074] The difference between Example 2 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 90:10.

[0075] The difference between Example 3 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 85:15.

[0076] The difference between Example 4 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 80:20.

[0077] The difference between Example 5 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 75:25.

[0078] The difference between Example 6 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 70:30.

[0079] The difference between Example 7 and Example 1 is that the liquid desulfurizer based on the alkali-making mother liquor and the waste liquid of the all-vanadium redox flow battery is compounded from components A and B in a mass ratio of 65:35.

[0080] Example 8 is different from Example 1 in that a liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid is prepared by compounding component A and component B in a mass ratio of 95:5. Component A is made from raw materials with the following mass percentages: 65 wt% alkali-making mother liquor, 18 wt% glycerol water, 6 wt% sorbitol, 6 wt% sodium citrate, 1.5 wt% cyclohexanone peroxide, and 3.5 wt% petroleum ether.

[0081] Example 9 is different from Example 1 in that component B is prepared by compounding the pretreatment liquid of spent vanadium redox flow battery waste liquid and synergist A, and synergist A is manganese nitrate. The preparation method of the pretreatment liquid of spent vanadium redox flow battery waste liquid in component B is the same as that in Example 1. Specifically, 5 parts of 0.1 mol / L manganese nitrate are added to 100 parts of the pretreatment liquid of spent vanadium redox flow battery waste liquid, and the pH value of the solution is adjusted to 8.1 by adding 5 wt% calcium bicarbonate solution to obtain component B.

[0082] Example 10 is different from Example 1 in that component B is prepared by compounding the pretreatment liquid of spent vanadium redox flow battery waste liquid, synergist A and synergist B, synergist A is manganese nitrate, and synergist B is cerium nitrate.

[0083] The preparation method of the pretreatment liquid of spent vanadium redox flow battery waste liquid in component B is the same as that in Example 1. Specifically, 3 parts of 0.1 mol / L manganese nitrate and 2 parts of 0.1 mol / L cerium nitrate are added to 100 parts of the pretreatment liquid of spent vanadium redox flow battery waste liquid, and the pH value of the solution is adjusted to 8.1 by adding 5 wt% calcium bicarbonate solution to obtain component B.

[0084] Comparative Example 1 is different from Example 1 in that the liquid desulfurizer is only component A.

[0085] Comparative Example 2 is different from Example 1 in that the liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid is prepared by compounding component A and component B in a mass ratio of 97:2.

[0086] Comparative Example 3 is different from Example 1 in that the liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid is prepared by compounding component A and component B in a mass ratio of 62:38.

[0087] Performance detection - desulfurization efficiency: The test flue gas conditions are 60 m 3 / h, the content of sulfur dioxide (SO2) in the flue gas is 200 ± 5 ppm. During use, components A and B are fed separately. The feeding position is in the solution tank connected to the outlet of the high-temperature fan at the kiln tail. The dosage of the desulfurizer in the solution tank is 1200 kg. The sulfur dioxide (SO2) in the flue gas is introduced from the bottom of the solution tank. The test time is 1 h, and the concentration P of sulfur dioxide (SO2) in the flue gas in the front section of the outlet of the high-temperature fan at the kiln tail is measured every five minutes. 前 Meanwhile, the concentration P of sulfur dioxide (SO2) in the flue gas after being treated by the desulfurizer in the rear section of the outlet of the high-temperature fan at the kiln tail is measured. 后 Calculate the desulfurization efficiency ω (%) of the desulfurizer = (P 后 * 100) / P 前 . Obtain 13 desulfurization efficiency ω data, namely ω0, ω5, ω 10 , ω 15 , ω 20 , ω 25 , ω 30 , ω 35 , ω 40 , ω 45 , ω 50 , ω 55 , ω 60 . The average desulfurization efficiency ω 平 = (ω0 + ω5 + ω 10 + ω 15 + ω 20 + ω 25 + ω 30 + ω 35 + ω 40 + ω 45 + ω 50 + ω 55 + ω 60 ) / 13. Δω = ω0 - ω 60 . Δω is the change value of the desulfurization performance of the liquid desulfurizer after 1 h of adsorption.

[0088] Table 1: Desulfurization performance test parameter table of desulfurizers in Examples 1 - 10 and Comparative Examples 1 - 3

[0089] Combined with Examples 1 - 7 and Comparative Examples 1 - 3 and Table 1, it can be seen that it is appropriate to control the content of component B at 5 - 35 wt%. If the addition of component B is too low, the desulfurization activity of the system is low, affecting the final desulfurization efficiency (lower than 90%). If the addition of component B is too high, the increase in the overall desulfurization efficiency is not obvious, and excessive consumption of component B will increase the overall production cost and also increase the difficulty of treating heavy metal sewage in the spent desulfurizer.

[0090] Combined with Examples 1 - 7 and Comparative Examples 1 - 3 and Table 1 and Figures 1-4It can be seen that it is appropriate to control the content of component B at 15-25 wt%. Considering comprehensively, the content of component B controlled at 15% is the best.

[0091] Combining Example 1 with Examples 9-10 and Table 1, it can be seen that adding synergistic ions to the liquid desulfurizer, where the synergistic ions include divalent manganese and / or trivalent cerium, can form a complex system of vanadium ions, manganese ions and / or cerium ions to more efficiently catalyze the oxidation of sulfides. Combining with the alkaline absorption characteristics of the soda-making mother liquor, the desulfurization efficiency improvement rate is 1.2-2.0%. However, introducing synergistic ions will inevitably increase the cost of the liquid desulfurizer.

[0092] From Figures 1-2 and Figure 4 it can be known that the desulfurization efficiency of the liquid desulfurizer is the best in the initial state. As the adsorption proceeds, the desulfurization efficiency shows a downward trend until the desulfurization efficiency drops to 50% and then fails (when the desulfurization efficiency is lower than 50%, the sulfur dioxide content in the flue gas discharged is above 80 ppm, not meeting the environmental emission standard). From Figure 3 it can be known that as the content of component B increases, the smaller Δω is, the relatively longer the service life of the liquid desulfurizer is.

[0093] In summary, in the present invention, the mother liquor generated in the process of preparing sodium bicarbonate by the double decomposition method of industrial salt NaCl and the product after the pretreatment of the vanadium battery electrolyte fails are used to prepare a liquid desulfurizer. Vanadium ions are used to catalyze the oxidation of sulfides, and combined with the alkaline absorption characteristics of the soda-making mother liquor, it is used to efficiently remove sulfur dioxide in the flue gas of the cement plant, forming a desulfurization system with high redox activity, realizing an efficient and low-cost desulfurization process, with a desulfurization efficiency of over 90%. At the same time, the waste liquid is recycled to reduce the desulfurization cost.

[0094] It should be noted that: This specific embodiment is only an explanatory illustration of the technical solution of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A liquid desulfurizer based on alkali-making mother liquor and spent liquor of all-vanadium redox flow battery, characterized in that: It is prepared by compounding component A and component B in a mass ratio of (65 - 95):(5 - 35); component A is made from raw materials with the following mass percentages: 30 - 70wt% of soda-making mother liquor, 20 - 50wt% of glycerol water, 3 - 10wt% of polyol, 2 - 8wt% of sodium citrate, 0.5 - 3wt% of cyclohexanone peroxide, 1 - 5wt% of petroleum ether; component B includes the pretreatment liquid of the spent liquid of all-vanadium redox flow battery.

2. The liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery according to claim 1, wherein: The soda-making mother liquor in component A is a by-product in the ammonia-soda method or the combined soda-making method or the industrial salt double decomposition soda-making process, and the pH value of the soda-making mother liquor in component A is 7 - 10.

3. A liquid desulfurizer based on alkali-making mother liquor and spent waste liquid of all-vanadium redox flow battery according to claim 2, characterized in that: The soda-making mother liquor in component A is the mother liquor generated in the process of preparing sodium bicarbonate by the industrial salt NaCl double decomposition method, and the pH value of the soda-making mother liquor in component A is 7 - 10.

4. The liquid desulfurizer based on soda-making mother liquor and spent vanadium redox flow battery waste liquid according to claim 2, characterized in that: The soda-making mother liquor in component A is made from raw materials with the following mass percentages: 10 - 26.5wt% of NaCl, 5 - 25wt% of NH4Cl, 5 - 10wt% of NH4HCO3, 5 - 10wt% of Na2CO3, 3 - 8wt% of NaHCO3, and the balance is water.

5. A liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery according to claim 1, characterized in that: The pretreatment liquid of the spent liquid of all-vanadium redox flow battery is an alkaline mixed liquid formed after pretreatment of the strongly acidic waste liquid formed after the electrolyte of the all-vanadium redox flow battery fails.

6. A liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid according to claim 5, characterized in that: After the electrolyte of the all-vanadium redox flow battery fails, the total vanadium concentration in the strongly acidic waste liquid formed is 1-2.5 mol / L, and the valence states of vanadium ions are V 2+ , V 3+ , V 4+ , V 5+ in a mixed valence state, the sulfate ion concentration is 1-5 mol / L, and it contains Fe 3+ , Al 3+ , Ca 2+ impurity ions. The pH value of the strongly acidic waste liquid formed after the electrolyte of the all-vanadium redox flow battery fails is lower than 2.

0.

7. A liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery according to claim 5, characterized in that: The preparation method of the pretreatment liquid of the spent liquid of all-vanadium redox flow battery is as follows: Step 1, solution homogenization: Stir and mix the strongly acidic waste liquids formed after the electrolytes of multiple batches of all-vanadium redox flow batteries fail in an acid-resistant storage tank to make the strongly acidic waste liquids formed after the electrolytes of multiple batches of all-vanadium redox flow batteries fail be mixed and homogenized to obtain a mixed waste liquid, ensuring the stability of the composition of the mixed waste liquid; Step 2, primary filtration: Filter the mixed waste liquid, and the precision of the filter cloth used is <10 microns; Step 3, neutralization adjustment: Spray the pH regulator into the mixed waste liquid by using the multi-stage segmented atomization spraying method. The pH regulator is any one of a sodium carbonate solution with a mass concentration of 8 - 10%, a sodium bicarbonate solution with a mass concentration of 6 - 8%, an ammonia water with a mass concentration of 5 - 20%, and a sodium hydroxide solution with a mass concentration of 6 - 12%. Adjust the pH value to 3 - 4 in the first stage; adjust the pH to 6 - 7 in the second stage; Step 4, stabilization treatment: Add a stabilizer according to a mass ratio of 1:1 with vanadium ions. The stabilizer includes any one of an EDTA disodium solution with a mass concentration of 0.1 - 0.5%, a sodium citrate solution, a sodium hexametaphosphate solution, and a citric acid solution, ensuring that the vanadium ions in the solution are stable and do not precipitate, and at the same time finely adjusting the pH value of the solution to 7 - 9; Step 5, secondary filtration: Ultrafilter to remove the colloids and micro-precipitates generated during the neutralization adjustment and stabilization treatment processes to obtain the finished product of the pretreatment liquid of the spent liquid of all-vanadium redox flow battery.

8. A liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery according to claim 1, characterized in that: The glycerol concentration in the glycerol water is 30% - 50%; the polyol is at least one of propylene glycol, glycerol, butanediol, and sorbitol.

9. A preparation method of a liquid desulfurizer based on soda-making mother liquor and spent vanadium redox flow battery waste liquid according to any one of claims 1-8, characterized in that: It includes the following steps: Preparation of Component A: First, mix the alkali-making mother liquor and sodium citrate in proportion, stir evenly, and carry out a constant-temperature reaction for 0.5 - 2 h to obtain mixture A. Then, mix glycerol water, polyol, and petroleum ether in proportion and stir evenly. Under the water bath condition, control the solution temperature to be maintained at 20 - 25 °C. Add cyclohexanone peroxide to the solution while stirring. After the addition of cyclohexanone peroxide is completed, continue stirring for 20 - 40 min to obtain mixture B. Finally, add mixture B to mixture A according to the ratio and stir for 20 - 40 min to obtain Component A; Preparation of the pretreatment liquid for the spent liquid of the all-vanadium redox flow battery in Component B; During use, Components A and B are added separately for use to remove sulfur dioxide in the flue gas.

10. The preparation method of a liquid desulfurizer based on soda-making mother liquor and spent waste liquid of a vanadium redox flow battery according to claim 9, characterized in that: The dosing position of the liquid desulfurizer is at the cyclone of the secondary preheater or at the outlet of the high-temperature fan at the kiln tail.

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