ZERO-CAT stable desulfurization solution and control method

Abstract

The invention provides a desulfurization solution for ZERO-CAT stable desulfurization and a control method, and relates to the technical field of wet desulfurization. The ZERO-CAT stable desulfurization solution comprises an absorbent, a catalyst, a biological inhibitor and a surfactant, the catalyst comprises a chelating agent, and the chelating agent comprises nitrilotriacetic acid sodium salt, sodium hydroxide and water. The chelating agent comprises nitrilotriacetic acid sodium salt, has good biodegradability and is an environment-friendly chelating agent, and the biological inhibitor is added, so that the biological activity can be reduced, the activity of bacteria introduced into the air is further reduced, and the situation that the chelating agent is lost due to the fact that the bacteria act on the chelating agent is avoided; by adding the surfactant, sulfur particles generated in the desulfurization process can be wetted, so that the sulfur particles aggregate and sink to the bottom of the system, and the situation that the system is blocked and cannot operate normally due to the fact that sulfur in the system cannot be discharged is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of wet desulfurization, and in particular to a desulfurization solution and a control method for ZERO-CAT stable desulfurization. Background Art

[0002] The Chinese name of the ZERO-CAT desulfurization method is usually referred to as "zero emission catalytic desulfurization technology" or "zero emission desulfurization technology". The ZERO-CAT desulfurization method aims to achieve efficient removal of sulfur dioxide from exhaust gas while striving to minimize environmental pollution and achieve resource recycling.

[0003] The ZERO-CAT desulfurization method generally includes the use of absorbents and catalysts. Sulfur dioxide reacts with the absorbent or catalyst under specific conditions and is converted into harmless compounds, or is absorbed and converted into usable materials. The catalyst generally includes a chelating agent that can promote chemical reactions to improve the conversion efficiency of sulfur dioxide.

[0004] During the desulfurization process, the ZERO-CAT desulfurization method uses a fan to introduce air. The air contains more bacteria, which will cause the loss of chelating agent. In addition, more bacteria will affect the activity of dissolved gas in the desulfurization solution and reduce the absorption efficiency of sulfur dioxide by the desulfurization solution. Summary of the invention

[0005] The problem solved by the invention is how to solve the problem of chelating agent loss and reduced absorption efficiency of sulfur dioxide by desulfurization solution caused by more bacteria in the introduced gas during the desulfurization process.

[0006] In order to solve the above problems, the present invention provides a desulfurization solution and a control method for ZERO-CAT stable desulfurization.

[0007] In the first aspect, the present invention provides a desulfurization solution for ZERO-CAT stable desulfurization, comprising an absorbent and a catalyst, and also comprising a bio-inhibitor and a surfactant, wherein the bio-inhibitor comprises alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl acetaldehyde benzyl ammonium chloride and water, and the surfactant comprises nonylphenol C1.5 ethoxylate, isopropyl ethanol and water; the catalyst comprises a chelating agent, and the chelating agent comprises sodium salt of nitrilotriacetic acid, sodium hydroxide and water.

[0008] Optionally, the catalyst further comprises an iron ion catalyst, and the iron ion catalyst comprises chelated iron, sulfur, a monovalent metal salt and water.

[0009] Optionally, the monovalent metal salt is a potassium salt or a sodium salt.

[0010] Optionally, the desulfurization solution also includes a stabilizer, the content of the stabilizer is above 60 g / L, and the stabilizer is a potassium thiocyanate solution.

[0011] Optionally, the absorbent is a ferric ion solution, which includes EDTA ferric amine, nitrilotriacetic acid sodium salt and water.

[0012] Optionally, the desulfurization solution also includes a redox reaction calibration solution, the redox reaction calibration solution includes a calibration solution A and a calibration solution B, the calibration solution A includes potassium ferrocyanide, potassium ferrocyanide and water, and the calibration solution B includes potassium ferrocyanide, potassium ferrocyanide, potassium fluoride and water.

[0013] Optionally, the sulfur content of the desulfurization solution is 3.5-4.5wt%.

[0014] In a second aspect, the present invention provides a method for controlling ZERO-CAT stable desulfurization, wherein a ZERO-CAT desulfurization method is performed using a desulfurization solution for ZERO-CAT stable desulfurization as described in any one of the above items, comprising: The daily addition amount of surfactant is 10-80 ppmv of the desulfurization solution; The pH of the desulfurization solution is controlled between 8-9; The redox potential of the desulfurization solution is controlled between -120mv and -270mv.

[0015] Optionally, a catalyst is continuously added, the catalyst including an iron ion catalyst, and the total iron ion content in the desulfurization solution is controlled to be no more than 2000 ppmw.

[0016] Optionally, during the ZERO-CAT desulfurization process, the relative density of the desulfurization solution is controlled at 1.03-1.25. If the relative density exceeds 1.28 due to salt deposition in the desulfurization solution, the desulfurization solution is replaced.

[0017] The beneficial effects of the desulfurization solution and control method for ZERO-CAT stable desulfurization of the present invention are as follows: the chelating agent includes sodium salt of nitrilotriacetic acid, which has good biodegradability and is an environmentally friendly chelating agent. The addition of bioinhibitors can reduce biological activity, thereby reducing the activity of bacteria introduced into the air, and avoiding the bacteria acting on the chelating agent to cause the loss of the chelating agent; the addition of surfactants can wet the sulfur particles generated in the desulfurization process, causing the sulfur particles to aggregate and sink to the bottom of the system, avoiding the inability to discharge sulfur in the system, resulting in system blockage and inability to operate normally. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. However, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the embodiments of the present invention are only used for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0019] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.

[0020] In the related technology, the Chinese name of the ZERO-CAT desulfurization method is usually called "zero emission catalytic desulfurization technology" or "zero emission desulfurization technology", which is a method for removing sulfur dioxide (SO2) from industrial waste gas. The main goal of this technology is to reduce or eliminate sulfur dioxide emissions to address environmental pollution and acid rain. ZERO-CAT technology generally includes the following steps: Catalyst use: This method uses a catalyst to promote chemical reactions to improve the conversion efficiency of sulfur dioxide; Reaction conditions: By optimizing reaction conditions (such as temperature, pressure and gas composition) to improve desulfurization efficiency; Absorption and reaction: Sulfur dioxide reacts with an absorbent or catalyst under specific conditions and is converted into harmless compounds, or is absorbed and converted into usable materials.

[0021] The ZERO-CAT desulfurization method generally includes absorbents and catalysts, which can vary depending on the specific process and design, but in general, the following are some examples of commonly used absorbents and catalysts: Absorbent 1. Sodium hydroxide (NaOH): commonly used in chemical absorption processes, it can react with sulfur dioxide to produce sodium sulfite.

[0022] 2. Ammonia (NH3): In some processes, ammonia can react with sulfur dioxide to form ammonium sulfate for selective absorption.

[0023] 3. Organic solvents: Certain alcohols and amines can be used as absorbents to remove sulfur dioxide through physical or chemical adsorption.

[0024] catalyst 1. Metal oxide catalysts: such as oxides of platinum, palladium or nickel, which can promote the conversion reaction of sulfur dioxide under certain conditions.

[0025] 2. Carriers such as Al2O3: Usually used as catalyst carriers to increase the surface area and stability of the catalyst.

[0026] 3. Other high-efficiency catalysts: such as certain metal-supported alloy catalysts, which can improve the selectivity and conversion rate of the reaction.

[0027] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a desulfurization solution and a control method for ZERO-CAT stable desulfurization.

[0028] A desulfurization solution for ZERO-CAT stable desulfurization provided in an embodiment of the present invention includes an absorbent and a catalyst, and also includes a bio-inhibitor and a surfactant. The bio-inhibitor includes alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl acetaldehyde benzyl ammonium chloride and water, and the surfactant includes nonylphenol C1.5 ethoxylate, isopropyl ethanol and water; the catalyst includes a chelating agent, and the chelating agent includes nitrilotriacetic acid sodium salt, sodium hydroxide and water.

[0029] In this embodiment, the chelating agent includes sodium salt of nitrilotriacetic acid, which has good biodegradability and is an environmentally friendly chelating agent. The addition of bioinhibitors can reduce biological activity, thereby reducing the activity of bacteria introduced into the air, and preventing bacteria from acting on the chelating agent to cause the loss of the chelating agent; the addition of surfactants can wet the sulfur particles generated during the desulfurization process, causing the sulfur particles to aggregate and sink to the bottom of the system, thereby preventing the sulfur in the system from being unable to be discharged, causing the system to be blocked and unable to operate normally.

[0030] Among them, the chelating agent composed of sodium nitrilotriacetic acid and sodium hydroxide has the following characteristics in terms of environmental protection and biodegradability: ‌Environmental protection‌: Sodium nitrilotriacetic acid (NTA) is a commonly used chelating agent, mainly used for the extraction of rare metals, complexing agents, water treatment agents, etc. It has good chelating properties and can form stable complexes with metal ions, thereby preventing discoloration, deterioration, turbidity and other problems caused by metals.

[0031] ‌Biodegradability‌: NTA is prepared from the natural amino acid L-glutamic acid, which is greener and more sustainable than other chelating agents. It has good biodegradability and can be decomposed by microorganisms in the environment, reducing the long-term impact on the environment.

[0032] In summary, the chelating agent composed of sodium nitrilotriacetic acid and sodium hydroxide performs well in environmental protection and biodegradability, and is suitable for a variety of environmental protection application scenarios.

[0033] The alkyl dimethyl benzyl ammonium chloride in the bio-inhibitor is a mixture of C12-14-16-18-alkyl dimethyl benzyl ammonium chloride, and the alkyl dimethyl acetaldehyde benzyl ammonium chloride is a mixture of C12-14-16-18-alkyl dimethyl acetaldehyde benzyl ammonium chloride.

[0034] Specifically, the mass proportion of alkyl dimethyl benzyl ammonium chloride in the bioinhibitor is less than 6%, the mass proportion of alkyl dimethyl acetaldehyde benzyl ammonium chloride is less than 6%, and the mass proportion of water is less than 90%; the mass proportion of nonylphenol C1.5 ethoxylate in the surfactant is less than 31%, the mass proportion of isopropyl alcohol is less than 3%, and the mass proportion of water is less than 70%; the mass proportion of sodium salt of nitrilotriacetic acid in the chelating agent is less than 40%, the mass proportion of sodium hydroxide is less than 2%, and the mass proportion of water is less than 65%.

[0035] Optionally, the catalyst further comprises an iron ion catalyst, and the iron ion catalyst comprises chelated iron, sulfur, a monovalent metal salt and water.

[0036] In this optional embodiment, the iron ion catalyst is a complex containing iron ions, similar to a cage chemical. 2+ and Fe 3+ The H2S in the gas is converted into S element, i.e. sulfur particles. Since the solution will be lost with the water washing sulfur, it is necessary to continuously add iron ion catalyst through a metering pump.

[0037] Optionally, the monovalent metal salt is a potassium salt or a sodium salt.

[0038] Specifically, the mass proportion of chelated iron in the iron ion catalyst is less than 3%, the mass proportion of sulfur is 5%-15%, and the mass proportion of potassium salt or sodium salt is less than 25%.

[0039] Optionally, the desulfurization solution also includes a stabilizer, the content of the stabilizer is above 60 g / L, the stabilizer is a potassium thiocyanate solution, and the mass fraction of potassium thiocyanate is less than 50%.

[0040] In this optional embodiment, the stabilizer is used to prevent the chelating agent from degrading. When there is no stabilizer, the consumption of the chelating agent in the redox process is too large. When the stabilizer content is above 60g / L, the consumption of the chelating agent in the redox process becomes lower, thereby extending the service life of the chelating agent and saving the cost of the chelating agent.

[0041] Optionally, the absorbent is a ferric ion solution, which includes EDTA ferric amine, nitrilotriacetic acid sodium salt and water.

[0042] Specifically, in the iron ion solution, the mass proportion of EDTA ferric amine is less than 40%, the mass proportion of nitrilotriacetic acid sodium salt is less than 12%, and the mass proportion of water is less than 50%.

[0043] Optionally, the desulfurization solution also includes a redox reaction calibration solution, the redox reaction calibration solution includes a calibration solution A and a calibration solution B, the calibration solution A includes potassium ferrocyanide, potassium ferrocyanide and water, and the calibration solution B includes potassium ferrocyanide, potassium ferrocyanide, potassium fluoride and water.

[0044] In this optional embodiment, the redox reaction calibration solution is used to calibrate the redox potential (ORP) instrument, and the ORP instrument needs to be calibrated regularly during use. The mass proportion of potassium ferrocyanide in calibration solution A is less than 5%, and the mass proportion of potassium ferrocyanide is less than 2%; the mass proportion of potassium ferrocyanide in calibration solution B is less than 5%, the mass proportion of potassium ferrocyanide is less than 2%, and the mass proportion of potassium fluoride is less than 4%.

[0045] Optionally, the sulfur content of the desulfurization solution is 3.5-4.5wt%.

[0046] The available method for determining the percentage of sulfur content includes the following experimental steps: 1. Place a clean filter paper on a watch glass and bake in an oven at 80 degrees Celsius for 5 minutes. 2. Remove the filter paper from the oven and place it in anhydrous sulfuric acid for drying until it cools down; 3. Use a balance to weigh the slot filter paper and record the weight; 4. Take a sample of the ZERO-CAT desulfurization solution and shake it evenly. Place the slot filter paper in the filter funnel and place it above the receiving bottle; 5. Weigh 25 ml of the sample solution, transfer it into a 50 ml beaker, and record the weight; 6. Pour the sample solution from step 5 into the filter funnel and pour all the anhydrous sulfuric acid from the beaker into the funnel; 7. Filter the sample solution of step 5; 8. Use distilled water to clean the funnel and filter paper; 9. Repeat the cleaning until all the anhydrous sulfuric acid and the proportioning solution on the surface of the tank filter paper are cleaned; 10. Remove the slotted filter paper from the funnel and place it on a watch glass; 11. Place the watch glass in the oven and bake at 80 degrees Celsius for 1 hour; 12. Remove the watch glass from the oven and place it in dry anhydrous sulfuric acid until it cools. 13. Weigh the filter paper and record the reading; 14. Use the following formula (I) to calculate the percentage of sulfur content.

[0047] (Weight of filter paper and sulfur weighed in step 13 wt - weight of filter paper weighed in step 3 wt) x 100 = weight of sample solution taken in step 5 (I) A control method for ZERO-CAT stable desulfurization provided in an embodiment of the present invention performs stable desulfurization on a ZERO-CAT desulfurization method using a desulfurization solution for ZERO-CAT stable desulfurization as described in any one of the above items, comprising: The daily addition amount of surfactant is 10-80 ppmv of the desulfurization solution; The pH of the desulfurization solution is controlled between 8-9; The redox potential of the desulfurization solution is controlled between -120mv and -270mv.

[0048] In this embodiment, the stability of the ZERO-CAT system is reflected by pH and ORP (oxidation-reduction potential); if the pH is too low, insufficient absorption may occur, resulting in excessive H2S in the purified gas and failure to meet customer requirements; if the pH is too high, more side reactions may occur, and H2S directly reacts with alkali (KOH) to generate thiosulfate, resulting in increased alkali consumption. Excessive accumulation of salts in the system will affect the ability of the desulfurization solution to absorb H2S and O2. Normally, excessive accumulation of salts will cause the system specific gravity to be greater than 1.28, and the system catalyst solution needs to be replaced as a whole. Therefore, in order to maintain the stability of the desulfurization system, the pH needs to be controlled between 8 and 9.

[0049] Fe in the system as reflected by the system ORP 2+ / Fe 3+ If the ORP value of the system is too low, it means that the reaction is excessive, which will cause Fe 2+ Too much Fe 2+It reacts with S to generate FeS precipitate, which destroys the system catalyst and completely loses this part of the precipitated catalyst. If the ORP value of the system is too high, it means excessive oxidation. Too much oxidizing air will cause the system to produce more thiosulfate and sulfate, causing excessive accumulation of salts in the system. Therefore, in order to maintain the stability of the desulfurization system, the redox potential of the desulfurization solution is controlled between -120mv and -270mv.

[0050] If pH and ORP are controlled smoothly, the H2S content in the purified gas from the system will meet the standard and be less than 10mg / m 3 , so that the concentration of catalyst iron ions is stable.

[0051] The surfactant is used to wet the sulfur particles in the system, causing them to aggregate and sink to the bottom of the system. 3 When operating, a dosage of 10-80 ppmv per day is sufficient to wet the sulfur particles; if no surfactant is added, the sulfur in the system will not be discharged, the system will be blocked and cannot operate normally.

[0052] Specifically, the pH value measurement range of ZERO-CAT desulfurization solution should be within 23℃±2℃, because the pH value will increase by 0.1 unit for every 3 degrees Celsius increase in the temperature of the desulfurization solution. Sampling and analysis should be carried out at 23℃, and the measurement results will also be based on the pH value at 23 degrees Celsius; and the redox potential will also be affected by temperature, so it is also measured at 23 degrees Celsius.

[0053] The redox electrode should always be immersed in Orion #900001 solution.

[0054] The redox potential can be measured by the following steps: 1. Turn on the pH meter; 2. Press the mV button on the pH meter. 3. Place the ORP redox electrode immersed in Orion #900001 solution in a beaker filled with distilled water; 4. Connect the ORP redox electrode and the pH meter; 5. Pour 15 ml of calibration solution A and calibration solution B into two small beakers respectively; 6. Rinse the ORP redox electrode with distilled water and wipe it dry; 7. Place the ORP redox electrode in calibration solution A until the reading stabilizes; 8. Use the standard knob to adjust the pH meter reading until it reads +192 mV; 9. Rinse the ORP redox electrode with distilled water and wipe it dry; 10. Place the ORP redox electrode in calibration solution B until the reading stabilizes; 11. Use the standard knob to adjust the pH meter reading until it reads +256mV (this operation depends on the pH meter); 12. Repeat steps 6 to 11 above until the pH meter readings in the two calibration solutions are consistent with the ORP redox electrode readings; 13. Allow the unfiltered ZERO-CAT desulfurization solution to reach room temperature of 22 degrees Celsius; 14. Rinse the ORP redox electrode with distilled water and wipe it dry; 15. Place the ORP redox electrode in the ZERO-CAT desulfurization solution until the reading stabilizes and record the reading.

[0055] Optionally, a catalyst is continuously added, the catalyst including an iron ion catalyst, and the total iron ion content in the desulfurization solution is controlled to be no more than 2000 ppmw.

[0056] In this optional embodiment, the content of iron ions in the iron ion catalyst in the total desulfurization solution does not exceed 2000 ppmw.

[0057] Furthermore, the absorbent is an iron ion solution, and the content of iron ions in the iron ion solution in the total desulfurization solution does not exceed 1000 ppmw.

[0058] Specifically, the iron ion content can be measured by the following steps: 1. Take samples of ZERO-CAT desulfurization solution; 2. Filter approximately 15 ml of the sample solution using a 0.45 μm, 25 mm syringe filter (first draw the sample solution into the syringe, then place the filter at the end of the syringe, and inject the sample solution through the filter into a 50 ml beaker to obtain the filtrate); 3. Use a pipette to transfer 10 ml of the filtrate into a 50 ml volumetric flask; 4. Pour distilled water into a 50 ml volumetric flask and mark it (mark on the bottom of the half-moon flask and shake evenly); 5. Use a pipette to extract 2 ml of filtrate from the 50 ml volumetric flask and inject it into the 100 ml volumetric flask; 6. Fill the 100 ml volumetric flask with distilled water and mark it; 7. Pour at least 40 ml of the filtrate from the 100 ml volumetric flask into a new 50 ml beaker; 8. Press the Hach DR / 820 Colorimeter Device EXIT button to turn on the device; 9. Confirm whether the program number displayed in the lower left corner is always 33. If so, see step 11; 10. If the program number displayed in the lower left corner is not 33, press the PRGM button and enter 33; 11. Pour the solution prepared in step 7 into a dedicated ampoule to the required scale, tighten the cap to keep the ampoule clean, put it into the instrument, and press the ZERO button of the instrument as a standard reference; 12. Carefully take out the ampoule, open it, add the color developer o-phenanthroline, tighten the cap, shake it several times to quickly mix the diluted solution with o-phenanthroline, and put it back into the instrument; 13. Press the TIMER button to start the timing device and start timing for three minutes (the time can be extended to ensure that the reagent inside the syringe is fully reflected); 14. Wipe the fingerprints and liquid on the outside of the syringe clean; 15. When the timer sounds, place the syringe used as the standard reference inside the colorimeter device and seal the cap; 16. Press the ZERO button and wait for the screen to display 0.00; 17. Remove the standard reference syringe from the colorimeter device, replace it with the sample solution syringe, and cap it; 18. Press the READ button and wait for the measured value to be read, which should be between 0.00 and 3.00 mg / L iron. 19. Multiply the read value by the dilution factor 250. The result is the actual iron ion concentration in the sample solution before dilution (in mg / L). 20. Divide by the specific gravity of the sample solution to obtain the iron ion concentration in the sample solution (in mg / kg or ppmw).

[0059] Optionally, during the ZERO-CAT desulfurization process, the relative density of the desulfurization solution is controlled at 1.03-1.25. If the relative density exceeds 1.28 due to salt deposition in the desulfurization solution, the desulfurization solution is replaced.

[0060] Normally, the more salts accumulate, the greater the relative density. If the relative density of the desulfurization solution is too high due to excessive salt deposition, it will affect the solution's ability to absorb H2S and O2. Therefore, the relative density of the desulfurization solution is controlled at 1.03-1.25. If the relative density exceeds 1.28, the desulfurization solution should be replaced.

[0061] Specifically, the relative density of the desulfurization solution can be measured by the following steps: 1. Sample the ZERO-CAT desulfurization solution and make it reach 23 degrees Celsius. The sulfur will settle at the bottom of the sampling container and filter it to remove a large amount of floating sulfur on the surface of the sampling solution. 2. Using an analytical balance, weigh the 100 mL volumetric flask; 3. Slowly pour the ZERO-CAT sampling solution into the beaker without destroying the deposited sulfur at the bottom of the volumetric flask, allowing a small amount of sulfur to pour into the beaker; 4. Using an analytical balance, weigh the 100 mL volumetric flask and record the reading; 5. Calculate the specific gravity using the following formula (II).

[0062] Weight of the mixed solution (step 4) ÷ 100 = Specific gravity of the sample solution (gm / cc) Formula (II) Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A desulfurization solution for ZERO-CAT stable desulfurization, comprising an absorbent and a catalyst, characterized in that: The invention also comprises a bio-inhibitor and a surfactant, wherein the bio-inhibitor comprises alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl acetaldehyde benzyl ammonium chloride and water, and the surfactant comprises nonylphenol C1.5 ethoxylate, isopropyl alcohol and water; and the catalyst comprises a chelating agent, and the chelating agent comprises sodium salt of nitrilotriacetic acid, sodium hydroxide and water.

2. The desulfurization solution for ZERO-CAT stable desulfurization according to claim 1, characterized in that: The catalyst further comprises an iron ion catalyst, and the iron ion catalyst comprises chelated iron, sulfur, a monovalent metal salt and water.

3. The desulfurization solution for ZERO-CAT stable desulfurization according to claim 2, characterized in that: The monovalent metal salt is a potassium salt or a sodium salt.

4. The desulfurization solution for ZERO-CAT stable desulfurization according to claim 2, characterized in that: The desulfurization solution also includes a stabilizer, the content of the stabilizer is above 60 g / L, and the stabilizer is a potassium thiocyanate solution.

5. The desulfurization solution for ZERO-CAT stable desulfurization according to claim 1, characterized in that: The absorbent is an iron ion solution, which includes EDTA iron amine, nitrilotriacetic acid sodium salt and water.

6. The desulfurization solution for ZERO-CAT stable desulfurization according to claim 1, characterized in that: The desulfurization solution also includes a redox reaction calibration solution, which includes a calibration solution A and a calibration solution B. The calibration solution A includes potassium ferrocyanide, potassium ferrocyanide and water, and the calibration solution B includes potassium ferrocyanide, potassium ferrocyanide, potassium fluoride and water.

7. The desulfurization solution with ZERO-CAT stable desulfurization according to claim 1, characterized in that: The sulfur content of the desulfurization solution is 3.5-4.5wt%.

8. A method for controlling ZERO-CAT stable desulfurization, characterized in that: The ZERO-CAT desulfurization method using the ZERO-CAT stable desulfurization solution according to any one of claims 1 to 7 is controlled, comprising: The surfactant is added in an amount of 10-80 ppmv of the desulfurization solution per day; The pH of the desulfurization solution is controlled between 8 and 9; The redox potential of the desulfurization solution is controlled between -120mv and -270mv.

9. The ZERO-CAT stable desulfurization control method according to claim 8, characterized in that: The catalyst is continuously added, and the catalyst includes an iron ion catalyst, so that the total iron ion content in the desulfurization solution is controlled not to exceed 3000 ppmw.

10. The ZERO-CAT stable desulfurization control method according to claim 8, characterized in that: During the ZERO-CAT desulfurization process, the relative density of the desulfurization solution is controlled at 1.03-1.

25. If the relative density of the desulfurization solution exceeds 1.28 due to salt deposition in the desulfurization solution, the desulfurization solution is replaced.