Efficient wet desulphurization synergist and preparation method thereof

Abstract

The invention discloses an efficient wet desulfurization synergist and a preparation method thereof, and relates to the technical field of flue gas desulfurization. The efficient wet desulphurization synergist comprises the following raw materials in parts by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of binary acid, 5-6 parts of a surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt and 2-5 parts of a pH buffer agent. The preparation method comprises the following steps: reacting cyanuric chloride with lauryl amine to generate a monosubstituted compound; then reacting with L-asparaginic acid to generate a disubstituted compound; reacting with diethylenetriamine to generate a bis-triazine ring compound; and finally, reacting with sodium 2-chloroethanesulfonate to generate the surfactant. The high-efficiency wet desulphurization synergist prepared by the invention has a desulphurization effect.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas desulfurization, and in particular to a high-efficiency wet desulfurization synergist and a preparation method thereof. Background Art

[0002] The current energy structure is highly dependent on coal, of which more than 84% is used through combustion. The flue gas emitted by coal combustion contains a large amount of SO2 and NO x and other pollutants, leading to environmental pollution problems. Existing limestone-gypsum wet flue gas desulfurization devices in thermal power plants generally have technical difficulties such as high energy consumption, high operating costs, and poor adaptability to the sulfur content of coal types. Although the desulfurization efficiency can be improved by modifying the desulfurization equipment system, this method is difficult to implement considering the high cost of capacity expansion and modification of the desulfurization equipment and the long modification construction period. On the premise of keeping the original desulfurization equipment unchanged, the idea of ​​adding desulfurization enhancers to the limestone slurry to meet the design desulfurization efficiency of the desulfurization system has become the focus of current desulfurization industry research.

[0003] Chinese invention patent publication number CN108114587A discloses a desulfurization synergist for wet flue gas desulfurization. The desulfurization synergist comprises the following raw materials in weight percentage: 54%-65% dextran sodium bisulfate, 5%-9% disodium lauryl sulfosuccinate, 7%-12% polyvinyl alcohol, 12%-16% citric acid, 2%-5% sodium carboxymethyl cellulose, and 1%-4% phenol red sodium salt. The desulfurization synergist provided by the invention can effectively reduce SO2 emissions, is not corrosive to the steel, lining rubber, etc. of the original system, and does not cause secondary pollution, but its desulfurization efficiency is average. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a high-efficiency wet desulfurization synergist and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions: A high-efficiency wet desulfurization synergist comprises the following raw materials in parts by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of dibasic acid, 5-6 parts of surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt, 2-5 parts of pH buffer; The surfactant is prepared by the following method: S1: Cyanuric chloride reacts with dodecylamine to form a monosubstituted compound; the reaction equation is as follows:

[0006] S2: L-aspartic acid reacts with a monosubstituted compound to form a disubstituted compound; the reaction equation is as follows:

[0007] S3: The disubstituted compound reacts with diethylenetriamine to form a bistriazine ring compound; the reaction equation is as follows:

[0008] S4: The bistriazine ring compound reacts with sodium 2-chloroethylsulfonate to form a surfactant; the reaction equation is as follows:

[0009] In step S1, the molar ratio of cyanuric chloride to dodecylamine is 1:(1-1.2).

[0010] In step S2, the molar ratio of the L-aspartic acid to the monosubstituted compound is (1.1-1.3):1.

[0011] In step S3, the molar ratio of the disubstituted compound to diethylenetriamine is (2.1-2.2):1.

[0012] In step S4, the molar ratio of the bistriazine ring compound to sodium 2-chloroethylsulfonate is 1:(2.1-2.3).

[0013] The dibasic acid is one of adipic acid and sebacic acid.

[0014] The magnesium salt is one of magnesium chloride and magnesium sulfate.

[0015] The sodium salt is one of sodium sulfate and sodium chloride.

[0016] The pH buffer is one of potassium phosphate buffer and sodium phosphate buffer.

[0017] A method for preparing a high-efficiency wet desulfurization synergist comprises the following steps: (1) Weigh by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of dibasic acid, 5-6 parts of surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt, and 2-5 parts of pH buffer; (2) Mix and stir the above materials until they are fully mixed, add them into a planetary ball mill, and grind them into powder to obtain a high-efficiency wet desulfurization synergist.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention include: The present invention prepares a new type of surfactant, which, when added to the formula of a desulfurization synergist, can improve the adsorption capacity of SO2 by increasing solubility, surface hydration and adsorption, and has excellent desulfurization efficiency. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0020] Example 1 Preparation of surfactant: S1: In an ice bath, 200 ml of toluene and 0.1 mol of cyanuric chloride were added to a reaction kettle, stirred and mixed, and 50 ml of a toluene solution containing 0.1 mol of dodecylamine was added dropwise. The mixture was added dropwise for 30 min, and the mixture was kept at 0°C for 4 h. The mixture was washed with 50 ml of a 0.1 mol / L hydrochloric acid solution and 50 ml of deionized water, respectively. The organic phase was dried over 10 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 h to obtain a monosubstituted compound. Its H NMR spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 6.24 (t, J =4.6 Hz, 1H), 3.53 (td, J = 7.2, 4.6 Hz, 2H), 1.79 - 1.64 (m, 2H), 1.41 - 1.20(m, 18H), 0.97 - 0.82 (m, 3H); S2: 150 ml of acetone and 0.1 mol of the monosubstituted compound were added to a reaction kettle and stirred to mix. 0.11 mol of L-aspartic acid was dissolved in 150 ml of a 5 wt% NaOH aqueous solution and added dropwise to the reaction kettle over 1 hour. The pH value was adjusted to 11 with a 1 M NaOH aqueous solution, the temperature was raised to 30°C, the reaction was carried out for 6 hours, and the mixture was cooled to room temperature. The pH value was adjusted to 2 with a 1 M hydrochloric acid solution. The mixture was extracted three times with 200 ml of toluene (each time). The organic phases were combined, washed with 200 ml of deionized water, dried over 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 hours to obtain a disubstituted compound. Its H NMR spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d) δ 11.96 (s, 1H), 10.01 (s, 1H), 9.00 (d, J = 8.2 Hz, 1H), 6.17(t, J = 4.6 Hz, 1H), 4.81 (q, J = 8.3 Hz, 1H), 3.52 (td, J = 7.1, 4.6 Hz,2H), 3.18 - 3.04 (m, 1H), 2.85 (dd, J = 16.8, 8.4 Hz, 1H), 1.78 - 1.65 (m,2H), 1.41 - 1.21 (m, 18H), 0.95 - 0.84 (m, 3H); S3: 200 ml of deionized water, 8 g of NaOH, and 0.21 mol of the disubstituted compound were added to a reaction kettle and stirred to mix. Then, 0.1 mol of diethylenetriamine was dissolved in 50 ml of acetone and added dropwise to the reaction kettle over a period of 30 min. The temperature was raised to 60°C and the reaction was carried out for 8 h. The pH value was adjusted to 2 with 1 mol / L hydrochloric acid solution. The mixture was extracted three times with toluene (200 ml each time). The organic phases were combined, washed with 200 ml of deionized water, dried with 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 h to obtain a bistriazine ring compound. Its H NMR spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 11.96 (s, 2H), 10.01(s, 2H), 9.03 (d, J = 8.2 Hz, 2H), 6.31 (t, J = 4.7 Hz, 2H), 6.20 (t, J = 4.6Hz, 2H), 4.81 (q, J = 8.3 Hz, 2H), 3.75 (q, J = 4.9 Hz, 4H), 3.52 (td, J =7.2, 4.6 Hz, 4H), 3.18 - 2.99 (m, 6H), 2.92 - 2.78 (m, 3H), 1.79 - 1.64 (m,4H), 1.42 - 1.21 (m, 36H), 0.97 - 0.82 (m, 6H); S4: 100 ml of deionized water, 0.21 mol of sodium 2-chloroethylsulfonate, and 0.5 mol of sodium carbonate were added to a reaction kettle, stirred to dissolve, and 300 ml of an acetone solution containing 0.1 mol of a bistriazine ring compound was added dropwise over 1 hour. The mixture was heated to 50°C and reacted for 20 hours. The mixture was cooled to room temperature, and 500 ml of anhydrous ethanol was added to stir and precipitate. The mixture was filtered and dried under vacuum at 50°C for 24 hours to obtain a surfactant. Its H NMR spectrum data are as follows: 1H NMR (300 MHz, Chloroform- d ) δ 8.61 (t, J = 3.4 Hz, 2H), 7.97 (d, J = 8.1 Hz, 2H), 6.20 (t, J = 4.6 Hz, 2H), 4.92 (dt, J = 8.2, 7.4Hz, 2H), 4.07 - 3.94 (m, 8H), 3.91 - 3.81 (m, 4H), 3.58 - 3.43 (m, 8H), 3.29- 3.15 (m, 2H), 2.96 (dd, J = 16.8, 7.3 Hz, 2H), 1.79 - 1.64 (m, 4H), 1.42 -1.21 (m, 36H), 0.95 - 0.85 (m, 6H).

[0021] Example 2 Preparation of surfactant: S1: In an ice bath, add 200 ml of toluene and 0.1 mol of cyanuric chloride to a reactor, stir and mix, add dropwise 50 ml of a toluene solution containing 0.11 mol of dodecylamine, and allow to react at 0°C for 5 h. Wash with 50 ml of a 0.1 mol / L hydrochloric acid solution and 50 ml of deionized water, respectively. Dry the organic phase with 10 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 60°C for 3 h to obtain a monosubstituted compound. S2: 150 ml of acetone and 0.1 mol of the monosubstituted compound were added to a reaction kettle and stirred to mix. 0.12 mol of L-aspartic acid was dissolved in 150 ml of a 5 wt% NaOH aqueous solution and added dropwise to the reaction kettle over 1 h. The pH value was adjusted to 11 with a 1 M NaOH aqueous solution, the temperature was raised to 40°C, the reaction was carried out for 5 h, and the mixture was cooled to room temperature. The pH value was adjusted to 2 with a 1 M hydrochloric acid solution. The mixture was extracted three times with 200 ml of toluene each time. The organic phases were combined, washed with 200 ml of deionized water, dried over 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 h to obtain a disubstituted compound. S3: 200 ml of deionized water, 8 g of NaOH, and 0.215 mol of the disubstituted compound were added to a reactor and stirred to mix. Then, 0.1 mol of diethylenetriamine was dissolved in 50 ml of acetone and added dropwise to the reactor for 30 min. The temperature was raised to 65°C and the reaction was carried out for 6 h. The pH value was adjusted to 2 with 1 mol / L hydrochloric acid solution. The mixture was extracted three times with toluene (200 ml each time). The organic phases were combined, washed with 200 ml of deionized water, dried with 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 h to obtain a bistriazine ring compound. S4: Add 100 ml of deionized water, 0.22 mol of sodium 2-chloroethylsulfonate and 0.5 mol of sodium carbonate to a reactor, stir to dissolve, add 300 ml of acetone solution containing 0.1 mol of a bistriazine ring compound dropwise for 1 hour, heat to 55°C, react for 18 hours, cool to room temperature, add 500 ml of anhydrous ethanol, stir to precipitate, filter, and vacuum dry at 50°C for 24 hours to obtain a surfactant.

[0022] Example 3 Preparation of surfactant: S1: In an ice bath, add 200 ml of toluene and 0.1 mol of cyanuric chloride to a reactor, stir and mix, then add dropwise 50 ml of a toluene solution containing 0.12 mol of dodecylamine for 30 min. React at 0°C for 6 h, wash with 50 ml of 0.1 mol / L hydrochloric acid solution and 50 ml of deionized water, respectively. Dry the organic phase with 10 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 60°C for 3 h to obtain a monosubstituted compound. S2: 150 ml of acetone and 0.1 mol of the monosubstituted compound were added to a reactor and stirred to mix. 0.13 mol of L-aspartic acid was dissolved in 150 ml of a 5 wt% NaOH aqueous solution and added dropwise to the reactor over 1 h. The pH value was adjusted to 11 with a 1 M NaOH aqueous solution, the temperature was raised to 50°C, the reaction was carried out for 4 h, and the mixture was cooled to room temperature. The pH value was adjusted to 2 with a 1 M hydrochloric acid solution. The mixture was extracted three times with 200 ml of toluene each time. The organic phases were combined, washed with 200 ml of deionized water, dried over 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 h to obtain a disubstituted compound. S3: 200 ml of deionized water, 8 g of NaOH, and 0.22 mol of the disubstituted compound were added to a reactor and stirred to mix. Then, 0.1 mol of diethylenetriamine was dissolved in 50 ml of acetone and added dropwise to the reactor for 30 minutes. The temperature was raised to 70°C and the reaction was carried out for 5 hours. The pH value was adjusted to 2 with 1 mol / L hydrochloric acid solution. The mixture was extracted three times with toluene (200 ml each time). The organic phases were combined, washed with 200 ml of deionized water, dried with 30 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60°C for 3 hours to obtain a bistriazine ring compound. S4: Add 100 ml of deionized water, 0.23 mol of sodium 2-chloroethylsulfonate and 0.5 mol of sodium carbonate to a reactor, stir to dissolve, add 300 ml of acetone solution containing 0.1 mol of a bistriazine ring compound dropwise for 1 hour, heat to 60°C, react for 15 hours, cool to room temperature, add 500 ml of anhydrous ethanol, stir to precipitate, filter, and vacuum dry at 50°C for 24 hours to obtain a surfactant.

[0023] Example 4 Preparation of high-efficiency wet desulfurization synergist: (1) Weigh: 10 g sodium formate, 5 g citric acid, 20 g adipic acid, 5 g surfactant (prepared in Example 1), 15 g magnesium chloride, 12 g sodium sulfate, and 2 g potassium phosphate buffer; (2) Mix the above materials and stir them at 300 r / min for 20 min at room temperature; add the mixed materials into a planetary ball mill, use grinding balls with a diameter of 5 mm and grinding balls with a diameter of 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 500 r / min for 15 min, stop for 15 min, grind at 500 r / min for another 15 min, and pass through a 1500 mesh sieve to obtain a high-efficiency wet desulfurization synergist.

[0024] Example 5 Preparation of high-efficiency wet desulfurization synergist: (1) Weigh: 15 g sodium formate, 8 g citric acid, 28 g adipic acid, 5.6 g surfactant (prepared in Example 2), 18 g magnesium sulfate, 16 g sodium sulfate, and 4 g potassium phosphate buffer; (2) Mix the above materials and stir them at 300 r / min for 20 min at room temperature; add the mixed materials into a planetary ball mill, use grinding balls with a diameter of 5 mm and grinding balls with a diameter of 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 500 r / min for 15 min, stop for 15 min, grind at 500 r / min for another 15 min, and pass through a 1500 mesh sieve to obtain a high-efficiency wet desulfurization synergist.

[0025] Example 6 Preparation of high-efficiency wet desulfurization synergist: (1) Weigh: 20 g sodium formate, 10 g citric acid, 30 g sebacic acid, 6 g surfactant (prepared in Example 3), 20 g magnesium sulfate, 18 g sodium chloride, and 5 g sodium phosphate buffer; (2) Mix the above materials and stir them at 300 r / min for 20 min at room temperature; add the mixed materials into a planetary ball mill, use grinding balls with a diameter of 5 mm and grinding balls with a diameter of 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 500 r / min for 15 min, stop for 15 min, grind at 500 r / min for another 15 min, and pass through a 1500 mesh sieve to obtain a high-efficiency wet desulfurization synergist.

[0026] Comparative Example 1 The raw material composition and preparation method of the high-efficiency wet desulfurization synergist are basically the same as those in Example 5, except that the surfactant (prepared in Example 2) is replaced by an equal weight of a surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that of Example 2, except that the amount of sodium 2-chloroethylsulfonate added in step S4 is replaced with 0.1 mol.

[0027] Comparative Example 2 The raw material composition and preparation method of the high-efficiency wet desulfurization synergist are basically the same as those in Example 5, except that the surfactant is replaced by an equal weight of a surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that of Example 2, except that the L-aspartic acid in step S1 is replaced by an equal molar amount of γ-aminobutyric acid.

[0028] Comparative Example 3 The raw material composition and preparation method of the high-efficiency wet desulfurization synergist are basically the same as those in Example 5, except that the surfactant is replaced by an equal weight of a surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that of Example 2, except that the dodecylamine in step S2 is replaced by an equimolar amount of n-butylamine.

[0029] Comparative Example 4 The raw material composition and preparation method of the high-efficiency wet desulfurization synergist are basically the same as those in Example 5, except that the surfactant is replaced by an equal weight of a surfactant prepared by the following method: The preparation method of the surfactant is basically the same as that of Example 2, except that the cyanuric chloride in step S1 is replaced by an equimolar amount of 1,2,3-trichloropropane.

[0030] The potassium phosphate buffer used in this application is prepared by the following method: weigh 7.63g of dipotassium hydrogen phosphate and 9.83g of potassium dihydrogen phosphate, add them to 800ml of deionized water, stir and dissolve, and dilute to 1L with deionized water to obtain potassium phosphate buffer; the sodium phosphate buffer is prepared by the following method: weigh 7.48g of disodium hydrogen phosphate and 8.81g of sodium dihydrogen phosphate, add them to 800ml of deionized water, stir and dissolve, and dilute to 1L with deionized water to obtain sodium phosphate buffer.

[0031] The desulfurization synergists prepared in Examples 4-6 and Comparative Examples 1-4 of the present application were applied to a flue gas desulfurization device in a wet desulfurization system to perform flue gas desulfurization, and the steps were as follows: (1) limestone (calcium carbonate content 97.8wt%) and water in a weight ratio of 15:100 to prepare limestone slurry; (2) Add the desulfurization synergist prepared in this application to the above-mentioned limestone slurry, wherein the desulfurization synergist accounts for 2wt% of the total mass, control the temperature to 50°C, the rotation speed to 500r / min, and stir for 4h; (3) Add limestone slurry with desulfurization synergist into the absorption tower and conduct performance test: the SO2 concentration of the inlet flue gas is designed to be 2000mg / Nm3 In the desulfurization system, the SO2 concentration in the outlet flue gas is monitored, and then the desulfurization efficiency is calculated. Desulfurization efficiency = (inlet SO2 concentration - outlet SO2 concentration) / inlet SO2 concentration. The results are shown in Table 1.

[0032] Table 1 Performance test data

[0033] It can be seen from Table 1 that the high-efficiency wet desulfurization synergists prepared in Examples 4-6 of the present application exhibit good desulfurization efficiency when added to limestone slurry.

[0034] The surfactant prepared in this application contains carboxyl, sulfonic acid, quaternary ammonium salt, hydrophobic long chain alkyl and triazine ring. Among them, the carboxyl and sulfonic acid groups interact with Ca through electrostatic interaction. 2+ The formation of complexes can effectively increase the solubility of limestone and directly improve the SO2 absorption efficiency; long-chain alkyl groups are adsorbed on the CaCO3 surface through hydrophobic association, with polar hydrophilic groups (carboxyl, sulfonic acid, quaternary ammonium salt) facing outward, making the CaCO3 surface hydrophilic, reducing particle agglomeration and expanding the effective reaction area, thereby indirectly improving the SO2 absorption efficiency through mass transfer enhancement; the dipole-dipole interaction between the N atom in the triazine ring and the S atom in SO2 and the hydrogen bond interaction between the O atom in SO2 and the H in -NH-, the two work synergistically to enhance its adsorption capacity for SO2.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in this field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A high-efficiency wet desulfurization synergist, characterized in that: The composition comprises the following raw materials in parts by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of dibasic acid, 5-6 parts of surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt, 2-5 parts of pH buffer; The surfactant is prepared by the following method: S1: Cyanuric chloride reacts with dodecylamine to form a monosubstituted compound; S2: L-aspartic acid reacts with a monosubstituted compound to form a disubstituted compound; S3: The disubstituted compound reacts with diethylenetriamine to form a bistriazine ring compound; S4: The bistriazine ring compound reacts with sodium 2-chloroethylsulfonate to form a surfactant.

2. A high-efficiency wet desulfurization synergist according to claim 1, characterized in that: In step S1, the molar ratio of cyanuric chloride to dodecylamine is 1:(1-1.2).

3. A high-efficiency wet desulfurization synergist according to claim 1, characterized in that: In step S2, the molar ratio of the L-aspartic acid to the monosubstituted compound is (1.1-1.3):

1.

4. A high-efficiency wet desulfurization synergist according to claim 1, characterized in that: In step S3, the molar ratio of the disubstituted compound to diethylenetriamine is (2.1-2.2):

1.

5. A high-efficiency wet desulfurization synergist according to claim 1, characterized in that: In step S4, the molar ratio of the bistriazine ring compound to sodium 2-chloroethylsulfonate is 1:(2.1-2.3).

6. A high-efficiency wet desulfurization synergist according to claim 1, characterized in that: The dibasic acid is one of adipic acid and sebacic acid.

7. The high-efficiency wet desulfurization synergist according to claim 1, characterized in that: The magnesium salt is one of magnesium chloride and magnesium sulfate.

8. The high-efficiency wet desulfurization synergist according to claim 1, characterized in that: The sodium salt is one of sodium sulfate and sodium chloride.

9. The high-efficiency wet desulfurization synergist according to claim 1, characterized in that: The pH buffer is one of potassium phosphate buffer and sodium phosphate buffer.

10. A method for preparing the high-efficiency wet desulfurization synergist according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh by weight: 10-20 parts of sodium formate, 5-10 parts of citric acid, 20-30 parts of dibasic acid, 5-6 parts of surfactant, 15-20 parts of magnesium salt, 12-18 parts of sodium salt, and 2-5 parts of pH buffer; (2) Mix and stir the above materials until they are fully mixed, add them into a planetary ball mill, and grind them into powder to obtain a high-efficiency wet desulfurization synergist.

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