A liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery and its preparation method

Abstract

The present invention relates to the technical field of desulfurizing agents, in particular to a liquid desulfurizing agent based on alkali-making mother liquor and spent liquor of a vanadium redox flow battery and a preparation method thereof. The liquid desulfurizing agent based on alkali-making mother liquor and spent liquor of a vanadium redox flow battery is composed of 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 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; component B includes a pretreatment solution of the spent liquor of a vanadium redox flow battery. The present invention realizes an efficient and low-cost desulfurization process by synergistically utilizing waste liquids, catalyzing and oxidizing sulfur-containing components with low valence by vanadium ions, and combining the alkaline absorption characteristics of alkali-making mother liquor. At the same time, it realizes the resource utilization of waste liquids, reduces the desulfurization cost, and is applicable to the field of industrial flue gas treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurization agents, and in particular to a liquid desulfurization 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. The sulfur content in limestone and coal directly affects the emission index of sulfur dioxide (SO2) of cement enterprises. Under the high requirements of 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 - enrichment in the wet desulfurization system accelerates equipment corrosion; third, the treatment of waste residue is difficult, the gypsum stacking occupies land resources, and it is easy to cause soil salinization.

[0004] However, 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 easy generation of secondary pollution. Summary of the Invention

[0005] In order to solve the defects of traditional desulfurization methods, the present invention provides a liquid desulfurization 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 vanadium battery electrolyte failure are used to prepare a liquid desulfurization agent. Vanadium ions are used to catalyze the oxidation of 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 desulfurization 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 desulfurization 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 of 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, the resource utilization of waste liquid is realized, the desulfurization cost is reduced, and it 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 baking soda 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 state of vanadium ions is V 2+ 、V 3+ 、V 4+ 、V 5+ mixed valence states, the sulfate radical concentration is 1-5 mol / L, and the impurity ions such as Fe 3+ 、Al 3+ 、Ca 2+ are less than 0.01 mol / L, and 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, and ensure 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 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%, 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, stir while adding, and continue to stir for 20-40 min after the addition of cyclohexanone peroxide is completed 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, the pre-treated liquid of the all-vanadium redox flow battery waste liquid;

[0027] During use, components A and B are added and used in a separate feeding manner to remove sulfur dioxide in the flue gas.

[0028] The preparation method of the liquid desulfurizer based on alkali-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 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: 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 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 alkali-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 to achieve an efficient and low-cost desulfurization process, and the desulfurization efficiency is 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 components containing low-valent sulfur, 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, achieving an efficient and low-cost desulfurization process. The desulfurization efficiency reaches over 90%, while realizing the resource utilization of waste liquid and reducing the desulfurization cost.

[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] 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 in 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, and 1 - 5 wt% of petroleum ether. Among them, the soda-making mother liquor in the A component is a by-product of the ammonia-soda process or the combined soda-making process or the industrial salt double decomposition soda-making process, and the pH value of the soda-making mother liquor in the A component is 7 - 10. Preferably, the soda-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 soda-making mother liquor in the A component is made of raw materials in 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 for the waste liquid of the all-vanadium redox flow battery. The pretreatment liquid for the waste 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 all-vanadium redox flow battery electrolyte fails. The total vanadium concentration in the strongly acidic waste liquid formed after the all-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 all-vanadium redox flow battery electrolyte fails is less than 2.0.

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

[0053] Preparation of the A component: First, mix the soda-making mother liquor and sodium citrate in proportion, stir evenly, and carry out a constant-temperature reaction 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, stir while adding, and continue to stir for 20 - 40 min after the addition of cyclohexanone peroxide is completed 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: The strongly acidic waste liquid formed after the failure of the electrolyte of multiple batches of all-vanadium redox flow batteries is stirred and mixed in an acid-resistant storage tank, so that the strongly acidic waste liquid formed after the failure of the electrolyte of multiple batches of all-vanadium redox flow batteries is mixed and homogenized to obtain a mixed waste liquid, ensuring the stable composition of the mixed waste liquid, and monitoring the pH value before and after mixing;

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

[0057] Step 3, neutralization adjustment: The pH regulator is atomized and sprayed into the mixed waste liquid by 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%. The pH value is adjusted to 3-4 in the first stage; the pH is adjusted to 6-7 in the second stage;

[0058] Step 4, stabilization treatment: A stabilizer is added 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, the pH value of the solution is finely adjusted to 7-9;

[0059] Step 5, secondary filtration: Ultrafiltration is used to remove the colloids and micro-precipitates 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 separately. The sulfur dioxide in the flue gas is removed. 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 separately, and the addition 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 more than 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 in mass percentages: 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 consists 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 radical 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 filter cloth with a mesh size of 2000, and the precision of the filter cloth is 6.5 microns;

[0070] Step 3, neutralization adjustment: Spray the pH regulator into the mixed waste liquid by means of multi-stage segmented atomization. The pH regulator is a sodium carbonate solution with a mass concentration of 10%. In the first stage, spray 10% sodium carbonate solution into the solution to adjust the pH value to 3.8; in the second stage, spray 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 an EDTA disodium solution with a mass concentration of 0.4%. The content of EDTA disodium 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 fine-tune 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, and thus obtain 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 separately for use 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 soda-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 soda-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 soda-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 soda-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 soda-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 soda-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 waste liquid of a vanadium redox flow battery 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% of alkali-making mother liquor, 18 wt% of glycerol water, 6 wt% of sorbitol, 6 wt% of sodium citrate, 1.5 wt% of cyclohexanone peroxide, and 3.5 wt% of petroleum ether.

[0081] Example 9 is different from Example 1 in that component B is prepared by compounding the waste liquid pretreatment solution of the vanadium redox flow battery and synergist A, and synergist A is manganese nitrate. The preparation method of the waste liquid pretreatment solution of the vanadium redox flow battery 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 waste liquid pretreatment solution of the vanadium redox flow battery, 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 waste liquid pretreatment solution of the vanadium redox flow battery, synergist A and synergist B, synergist A is manganese nitrate, and synergist B is cerium nitrate.

[0083] The preparation method of the waste liquid pretreatment solution of the vanadium redox flow battery 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 waste liquid pretreatment solution of the vanadium redox flow battery, 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 waste liquid of a vanadium redox flow battery 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 waste liquid of a vanadium redox flow battery 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 sulfur dioxide SO2 content in the flue gas is 200±5ppm. When in use, components A and B are added separately. The addition position is the solution tank connected to the outlet of the high-temperature fan at the end of the kiln. The amount of desulfurizer used in the solution tank is 1200kg. Sulfur dioxide SO2 in the flue gas is introduced from the bottom of the solution tank. The test time is 1h. The sulfur dioxide SO2 concentration P in the flue gas in front of the outlet of the high-temperature fan at the end of the kiln is tested every five minutes. 前 At the same time, the sulfur dioxide SO2 concentration P in the flue gas treated with desulfurizer at the outlet of the high-temperature fan at the end of the test kiln is tested. 后 , calculate the desulfurization efficiency of the desulfurizer ω (%) = (P 后 *100) / P 前 13 desulfurization efficiency ω data are obtained, 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 , 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 in desulfurization performance of the liquid desulfurizer after 1h of adsorption.

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

[0089]

[0090] It can be seen from Examples 1-7 and Comparative Examples 1-3 and Table 1 that the content of component B is preferably controlled at 5-35wt%. If the addition of component B is too low, the desulfurization activity of the system will be too low, affecting the final desulfurization efficiency (less than 90%). If the addition of component B is too high, the overall desulfurization efficiency will not be significantly increased. Excessive consumption of component B will increase the overall production cost and increase the difficulty of heavy metal wastewater treatment of the failed desulfurizer.

[0091] Combined with Examples 1-7 and Comparative Examples 1-3 and Tables 1 andFigures 1-4 It can be seen that it is appropriate to control the content of component B at 15-25 wt%. Considering comprehensively, the best content of component B is 15%.

[0092] Combining Example 1 with Examples 9-10 and referring to 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.

[0093] 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 progresses, the desulfurization efficiency shows a downward trend until the desulfurization efficiency drops to 50% and then it 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 and Δω becomes smaller, the service life of the liquid desulfurizer is relatively extended.

[0094] In summary, in the present invention, 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 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.

[0095] 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 mixing component A and component B in a mass ratio of (65-95):(5-35); Component A 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, 1-5 wt% of petroleum ether; Component B includes a pretreatment solution for the waste liquid of a vanadium redox flow battery; The pretreatment solution for the waste liquid of a vanadium redox flow battery is an alkaline mixture 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 concentration of sulfate radicals contained is 1-5 mol / L, and the content of Fe 3+ , Al 3+ , Ca 2+ impurity ions, and the pH value of the strongly acidic waste liquid formed after the vanadium redox flow battery electrolyte fails is lower than 2.

0.

2. The liquid desulfurizer based on soda-making mother liquor and spent waste liquid of all-vanadium redox flow battery according to claim 1, wherein: The soda-making mother liquor in the component A is a by-product of the ammonia-soda process, the combined soda-making process, 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.

3. A liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid according to claim 2, characterized in that: The soda-making mother liquor in the component A is the mother liquor generated during the preparation of baking soda 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.

4. A liquid desulfurizer based on alkali-making mother liquor and spent liquid of all-vanadium redox flow battery according to claim 2, characterized in that: 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.

5. A liquid desulfurizer based on alkali-making mother liquor and spent waste 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.

6. A preparation method of a liquid desulfurizer based on soda-making mother liquor and spent waste liquid of a vanadium redox flow battery according to any one of claims 1-5, characterized in that: It includes the following steps: 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 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 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 the component A. Preparation of the pretreatment liquid for the spent liquid of the all-vanadium redox flow battery in component B; The preparation method of the pretreatment liquid for the spent liquid of the all-vanadium redox flow battery is as follows: 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. 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 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. Step 4, stabilization treatment: Add a stabilizer according to 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 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. 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 for the spent liquid of the all-vanadium redox flow battery. During use, the components A and B are added separately for use to remove sulfur dioxide in the flue gas.

7. The preparation method of a liquid desulfurizer based on alkali-making mother liquor and spent vanadium redox flow battery waste liquid according to claim 6, 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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