Iron oxyhydroxide desulfurizer and preparation method thereof

Abstract

The invention relates to the technical field of desulfurizing agents, in particular to a ferric oxyhydroxide desulfurizing agent and a preparation method thereof. According to the iron oxyhydroxide desulfurizing agent, zinc oxide nanoparticles are doped on the surface of iron oxyhydroxide, then the zinc oxide nanoparticles and manganese dioxide form a core-shell structure with manganese dioxide as a shell and iron oxyhydroxide as a core, and finally the core-shell structure is loaded on carbon nanofibers to finally obtain the iron oxyhydroxide desulfurizing agent. The iron oxyhydroxide desulfurizer disclosed by the invention has excellent sulfur removal performance, can still keep relatively excellent sulfur removal performance under the condition that interfering ions such as PO4 < 3-> and SO3 < 2-> exist in water, and can be widely applied to the field of industrial sulfur removal.

Description

Technical Field

[0001] This invention relates to the field of desulfurizing agent technology, and in particular to a hydroxyl iron oxide desulfurizing agent and its preparation method. Background Technology

[0002] With the continuous development of industry, many industries closely related to daily life, such as oil refining, petrochemicals, pharmaceuticals, and leather tanning, also generate large amounts of sulfur-containing wastewater during their production processes. Sulfides exist in different states at different pH levels. When the wastewater is acidic, most of the sulfides escape from the water body as H2S and are released into the air; when the pH is between 5 and 7.5, S... 2- Hydrolysis produces a large amount of HS- in water; when pH > 7.5, it mainly exists as S. 2- SO4 2- SO3 2- These pollutants exist in water in various forms. When these pollutants are discharged directly into the environment without treatment, they turn water bodies black, corrode metal materials, harm human health, and cause significant environmental damage. Therefore, the deep removal of sulfides has become an urgent problem to be solved worldwide.

[0003] Iron hydroxyl oxide is an important desulfurizing agent with broad application prospects in fields such as heavy metal particle adsorption, organic matter degradation, solid / liquid phase desulfurization, and coal liquefaction.

[0004] Patent document CN202310514348.1 discloses a high-strength iron hydroxyl oxide desulfurizer and its preparation method. This invention's high-strength iron hydroxyl oxide desulfurizer uses Fe-β molecular sieve as the core layer and iron hydroxyl oxide as the shell layer, with the Fe-β molecular sieve coated with iron hydroxyl oxide. The molar ratio of SiO2 to Al2O3 in the Fe-β molecular sieve is 40-50. The high-strength iron hydroxyl oxide desulfurizer obtained by this invention has high strength, large sulfur penetration capacity, large specific surface area, and high mechanical strength. Furthermore, it does not pulverize after prolonged immersion in organic solvents during desulfurization, exhibiting high resistance to organic solvents, making it suitable for recycling after repeated desulfurization. However, when used for desulfurization in water, the water will contain PO4. 3- SO3 2- A large number of interfering ions, such as S, will interact with S. 2- Competition occurs between them, which can greatly affect the desulfurization effect. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a hydroxyl iron oxide desulfurizing agent and its preparation method, so as to solve the problem that traditional desulfurizing agents have poor desulfurization effect in water.

[0006] To achieve the above objectives, the present invention provides a method for preparing an iron hydroxyl oxide desulfurizing agent, comprising the following preparation steps: S1: Mix FeCl3 solution and SDS solution, add zinc oxide, adjust pH to 10-11, react at 100-130℃ for 7-9 h, filter, wash and dry to obtain iron hydroxyl oxide nanoparticles; S2: Add hydroxyl iron oxide nanoparticles to deionized water and sonicate at 230℃ for 0.5-1h. Then add concentrated hydrochloric acid and potassium permanganate and react at 20-30℃ for 5-15 min. Finally, transfer it to a reaction vessel and react at 100-120℃ for 4-8h. Cool, filter, wash and dry to obtain modified hydroxyl iron oxide nanoparticles. S3: Modified iron hydroxyl oxide nanoparticles, PAN, and PVP are added to DMF, stirred at 50-70℃ for 5-6 h, and sonicated for 20-30 min to obtain a mixed solution. The mixed solution is then electrospun to obtain the initial product. S4: The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h, then heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h, and then cooled to obtain hydroxyl iron oxide desulfurizer. Preferably, the weight ratio of FeCl3 solution, SDS solution and zinc oxide in step S1 is 20:15-25:0.3-0.5.

[0007] Preferably, the zinc oxide nanoparticles in step S1 have a particle size of 20-40 nm.

[0008] Preferably, the molar concentration of the FeCl3 solution in step S1 is 1 mol / L.

[0009] Preferably, the molar concentration of the SDS solution in step S1 is 5 mmol / L.

[0010] Preferably, the pH adjustment to 10-11 in step S1 is performed using a 1 mol / L sodium hydroxide solution.

[0011] Preferably, the drying in step S1 is performed at 60°C for 24 hours.

[0012] Preferably, the weight ratio of the iron hydroxyl oxide nanoparticles, deionized water, concentrated hydrochloric acid and potassium permanganate in step S2 is 0.3-0.5:30-40:0.75:0.4-0.6.

[0013] Preferably, the washing in step S2 is performed using anhydrous ethanol and deionized water.

[0014] Preferably, the weight ratio of the modified iron hydroxyl oxide nanoparticles, PAN, PVP and DMF in step S3 is 10-30:8:8:54-74.

[0015] Preferably, the specific parameters for electrospinning in step S3 are: pillow size 17G, applied voltage 13 / -1 kV, injection speed 0.06-0.15 mm / min, and receiving distance 120-180 mm.

[0016] Furthermore, the present invention also provides a hydroxyl iron oxide desulfurizing agent, which is prepared by the method for preparing hydroxyl iron oxide desulfurizing agents.

[0017] The beneficial effects of this invention are: This invention improves the desulfurization performance of the final desulfurizer by doping zinc oxide nanoparticles onto the surface of iron hydroxide, and further enhances the desulfurization performance of the desulfurizer in the presence of interfering ions in water.

[0018] By using manganese dioxide as the shell of iron hydroxyl oxide to form a core-shell structure, and then loading it onto carbon nanofibers, the desulfurization performance of the desulfurizing agent is improved. Most importantly, it can still maintain relatively excellent desulfurization performance in the presence of interfering ions in water.

[0019] A desulfurizing agent prepared by doping zinc oxide nanoparticles onto iron hydroxide and then forming a core-shell structure with manganese dioxide as the shell and iron hydroxide as the core through a hydrothermal reaction, and finally loading it onto carbon nanofibers, exhibits significantly improved desulfurization performance compared to desulfurizing agents obtained by directly loading zinc oxide, iron hydroxide, and manganese dioxide onto carbon nanofibers. Most importantly, it maintains superior desulfurization performance even in the presence of interfering ions in water, showing less influence from interfering ions, making it more suitable for both daily life and production. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0021] The properties or sources of the raw materials used in the embodiments and comparative examples of this invention are as follows: The zinc oxide nanoparticles, with a particle size of 30 nm, were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with product number Z112847.

[0022] Example 1: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 15g of 5mmol / L SDS solution, add 0.3g of zinc oxide, adjust the pH to 10 with 1mol / L sodium hydroxide solution, react at 100℃ for 7h, filter, wash, and dry at 60℃ for 24h to obtain iron hydroxyl oxide nanoparticles; (2) Add 30g of iron hydroxyl oxide nanoparticles to 3L of deionized water, sonicate at 230℃ for 0.5h, then add 75g of concentrated hydrochloric acid and 40g of potassium permanganate, react at 20℃ for 5min, and finally transfer it to a reaction vessel, react at 100℃ for 4h, cool, filter, wash and dry to obtain modified iron hydroxyl oxide nanoparticles; (3) 10g of modified iron hydroxyl oxide nanoparticles, 8g of PAN and 8g of PVP were added to 74g of DMF, stirred at 50℃ for 5 h and sonicated for 20 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.06 mm / min and the receiving distance was 120 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0023] Example 2: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 20g of 5mmol / L SDS solution, add 0.4g of zinc oxide, adjust the pH to 10.4 with 1mol / L sodium hydroxide solution, react at 115℃ for 8h, filter, wash, and dry at 60℃ for 24h to obtain hydroxyl iron oxide nanoparticles; (2) 40g of iron hydroxyl oxide nanoparticles were added to 3.5L of deionized water and sonicated at 230℃ for 1h. Then 75g of concentrated hydrochloric acid and 50g of potassium permanganate were added and reacted at 25℃ for 10min. Finally, the mixture was transferred to a reaction vessel and reacted at 110℃ for 6h. After cooling, filtering, washing and drying, modified iron hydroxyl oxide nanoparticles were obtained. (3) 20g of modified iron hydroxyl oxide nanoparticles, 8g of PAN and 8g of PVP were added to 64g of DMF, stirred at 60℃ for 6 h and sonicated for 25 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.09 mm / min and the receiving distance was 150 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0024] Example 3: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 20g of 5mmol / L SDS solution, add 0.5g of zinc oxide, adjust the pH to 11 with 1mol / L sodium hydroxide solution, react at 130℃ for 9h, filter, wash, and dry at 60℃ for 24h to obtain iron hydroxyl oxide nanoparticles; (2) 35g of hydroxyl iron oxide nanoparticles were added to 3L of deionized water and sonicated at 230℃ for 1h. Then 75g of concentrated hydrochloric acid and 45g of potassium permanganate were added and reacted at 25℃ for 15 min. Finally, the mixture was transferred to a reaction vessel and reacted at 120℃ for 8h. After cooling, filtering, washing and drying, modified hydroxyl iron oxide nanoparticles were obtained. (3) 30g of modified iron hydroxyl oxide nanoparticles, 8g of PAN and 8g of PVP were added to 54g of DMF, stirred at 50℃ for 6 h and sonicated for 30 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.12 mm / min and the receiving distance was 170 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0025] Example 4: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 25g of 5mmol / L SDS solution, add 0.5g of zinc oxide, adjust the pH to 11 with 1mol / L sodium hydroxide solution, react at 130℃ for 9h, filter, wash, and dry at 60℃ for 24h to obtain iron hydroxyl oxide nanoparticles; (2) Add 50g of iron hydroxyl oxide nanoparticles to 4L of deionized water, sonicate at 230℃ for 1h, then add 75g of concentrated hydrochloric acid and 60g of potassium permanganate, react at 30℃ for 15min, and finally transfer it to a reaction vessel, react at 120℃ for 8h, cool, filter, wash and dry to obtain modified iron hydroxyl oxide nanoparticles. (3) 30g of modified iron hydroxyl oxide nanoparticles, 8g of PAN and 8g of PVP were added to 54g of DMF, stirred at 70℃ for 6 h and sonicated for 30 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.15 mm / min and the receiving distance was 180 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0026] Comparative Example 1: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 20g of 5mmol / L SDS solution, add 5g of 1ml / L zinc chloride solution, adjust the pH to 10.4 with 1mol / L sodium hydroxide solution, react at 115℃ for 8h, filter, wash, and dry at 60℃ for 24h to obtain iron hydroxyl oxide nanoparticles; The remaining steps are the same as in Example 2.

[0027] Comparative Example 2: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 20g of 5mmol / L SDS solution, add 0.4g of zinc oxide, adjust the pH to 10.4 with 1mol / L sodium hydroxide solution, react at 115℃ for 8h, filter, wash, and dry at 60℃ for 24h to obtain hydroxyl iron oxide nanoparticles; (3) 12.1g of iron hydroxyl oxide nanoparticles, 7.9g of MnO2, 8g of PAN and 8g of PVP were added to 64g of DMF, stirred at 60℃ for 6 h and sonicated for 25 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.09 mm / min and the receiving distance was 150 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0028] Comparative Example 3: A hydroxyl iron oxide desulfurizing agent, the specific preparation steps are as follows: (1) Mix 20g of 1mol / L FeCl3 solution and 20g of 5mmol / L SDS solution, adjust the pH to 10.4 with 1mol / L sodium hydroxide solution, react at 115℃ for 8h, filter, wash, and dry at 60℃ for 24h to obtain hydroxyl iron oxide nanoparticles; (2) 11.7g of iron hydroxyl oxide nanoparticles, 7.9g of MnO2, 0.4g of zinc oxide, 8g of PAN, and 8g of PVP were added to 64g of DMF and stirred at 60℃ for 6 h and sonicated for 25 min to obtain a mixed solution. The mixed solution was then electrospun to obtain the initial product. The electrospinning needle was 17G, the applied voltage was 13 / -1 kV, the injection speed was 0.09 mm / min, and the receiving distance was 150 mm. (4) The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

[0029] Performance testing Formulating S 2- For a water sample with a concentration of 100 mg / L, take 100 mL and place it in an Erlenmeyer flask. Weigh 0.1 g of the sample obtained in the examples and comparative examples and add it to the Erlenmeyer flask containing the sulfur water sample. At the same time, introduce a small amount of nitrogen gas above the liquid surface for protection, and seal the mouth of the flask with a sealing film. Then place the Erlenmeyer flask on a shaker and shake it slowly for 10-60 min. After standing, take the supernatant and determine the residual sulfur ions in the water sample using the iodometric method (HJ / T60-2000). The same sample was measured three times in parallel. The experimental temperature was 35℃. The test results are shown in Table 1.

[0030] Configuration S 2- Concentration of 100 mg / L, PO4 3- For a water sample with a concentration of 100 mg / L, take 100 mL and place it in an Erlenmeyer flask. Weigh 0.1 g of the sample obtained in the examples and comparative examples and add it to the Erlenmeyer flask containing the sulfur water sample. At the same time, introduce a small amount of nitrogen gas above the liquid surface for protection, and seal the mouth of the flask with a sealing film. Then place the Erlenmeyer flask on a shaker and shake it slowly for 10-60 min. After standing, take the supernatant and determine the residual sulfur ions in the water sample using the iodometric method (HJ / T60-2000). The same sample was measured three times in parallel. The experimental temperature was 35℃. The test results are shown in Table 1.

[0031] Configuration S 2- Concentration of 100 mg / L, SO3 2-For a water sample with a concentration of 100 mg / L, take 100 mL and place it in an Erlenmeyer flask. Weigh 0.1 g of the sample obtained in the examples and comparative examples and add it to the Erlenmeyer flask containing the sulfur water sample. At the same time, introduce a small amount of nitrogen gas above the liquid surface for protection, and seal the mouth of the flask with a sealing film. Then place the Erlenmeyer flask on a shaker and shake it slowly for 10-60 min. After standing, take the supernatant and determine the residual sulfur ions in the water sample using the iodometric method (HJ / T60-2000). The same sample was measured three times in parallel. The experimental temperature was 35℃. The test results are shown in Table 1.

[0032] Table 1 Performance Test Results <![CDATA[S 2- Removal rate (%) <![CDATA[S 2- Removal rate (%) / PO4 3- Interference 7-8]]> <![CDATA[S 2- Removal rate (%) / SO3 2- Interference 12-13]]> Example 1 97.4 94.6 93.2 Example 2 98.3 95.3 94.6 Example 3 97.7 93.8 92.5 Example 4 97.1 93.1 92.2 Comparative Example 1 97.2 92.4 90.3 Comparative Example 2 93.5 88.1 82.1 Comparative Example 3 91.5 83.8 77.5 Data analysis: The hydroxyl iron oxide desulfurizer of the present invention exhibits excellent desulfurization performance when applied to water for desulfurization, and it can still maintain relatively excellent desulfurization performance even in the presence of interfering ions in the water.

[0033] As can be seen from Example 2 and Comparative Example 1, the present invention can improve the desulfurization performance of the final desulfurizer by doping zinc oxide nanoparticles on the surface of iron hydroxyl oxide.

[0034] As can be seen from Example 2 and Comparative Example 2, by using manganese dioxide as the shell of iron hydroxyl oxide to form a core-shell structure with iron hydroxyl oxide, and then loading it onto carbon nanofibers, the desulfurization performance of the desulfurizing agent is improved; most importantly, it can still maintain relatively excellent desulfurization performance in the presence of interfering ions in water.

[0035] As can be seen from Examples 2 and 3, the desulfurizer prepared by doping zinc oxide nanoparticles onto iron hydroxide, forming a core-shell structure with manganese dioxide as the shell and iron hydroxide as the core through a hydrothermal reaction, and finally loading it onto carbon nanofibers, exhibits improved desulfurization performance compared to desulfurizers obtained by directly loading zinc oxide, iron hydroxide, and manganese dioxide onto carbon nanofibers. Most importantly, it maintains superior desulfurization performance even in the presence of interfering ions in water, showing less influence from interfering ions, making it more suitable for industrial desulfurization applications.

[0036] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0037] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a hydroxyl iron oxide desulfurizing agent, characterized in that, The preparation steps include the following: S1: Mix FeCl3 solution and SDS solution, add zinc oxide, adjust pH to 10-11, react at 100-130℃ for 7-9 h, filter, wash and dry to obtain iron hydroxyl oxide nanoparticles; S2: Add hydroxyl iron oxide nanoparticles to deionized water and sonicate at 230℃ for 0.5-1h. Then add concentrated hydrochloric acid and potassium permanganate and react at 20-30℃ for 5-15 min. Finally, transfer it to a reaction vessel and react at 100-120℃ for 4-8h. Cool, filter, wash and dry to obtain modified hydroxyl iron oxide nanoparticles. S3: Modified iron hydroxyl oxide nanoparticles, PAN, and PVP are added to DMF, stirred at 50-70℃ for 5-6 h, and sonicated for 20-30 min to obtain a mixed solution. The mixed solution is then electrospun to obtain the initial product. S4: The initial product is first heated to 250°C in air at a rate of 1°C / min and held for 1 h. Then it is heated to 600°C in nitrogen at a rate of 5°C / min and held for 1 h. After cooling, hydroxyl iron oxide desulfurizer is obtained.

2. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, In step S1, the weight ratio of FeCl3 solution, SDS solution and zinc oxide is 20:15-25:0.3-0.

5.

3. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The zinc oxide nanoparticles mentioned in step S1 have a particle size of 20-40 nm.

4. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The molar concentration of the FeCl3 solution in step S1 is 1 mol / L.

5. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The molar concentration of the SDS solution in step S1 is 5 mmol / L.

6. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The weight ratio of the iron hydroxyl oxide nanoparticles, deionized water, concentrated hydrochloric acid and potassium permanganate in step S2 is 0.3-0.5:30-40:0.75:0.4-0.

6.

7. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The weight ratio of the modified iron hydroxyl oxide nanoparticles, PAN, PVP and DMF in step S3 is 10-30:8:8:54-74.

8. The method for preparing the ferric hydroxide desulfurizer according to claim 1, characterized in that, The specific parameters for electrospinning in step S3 are: 17G needle, 13 / -1 kV applied voltage, 0.06-0.15 mm / min injection speed, and 120-180 mm receiving distance.

9. A hydroxyl iron oxide desulfurizing agent, characterized in that, The ferric hydroxide desulfurizer is prepared by the method for preparing ferric hydroxide desulfurizer according to any one of claims 1-8.