A functional fiber, a preparation method thereof and application thereof in adsorbing hydrogen sulfide gas

Abstract

The application provides a functional fiber and a preparation method and application thereof in adsorbing hydrogen sulfide gas, and relates to the technical field of adsorptive materials. Firstly, the acrylic fiber is aminated to load amine group functional groups on the fiber, so that the fiber has anion exchange performance; then metal ion exchange is performed to load metal ions on the fiber; finally, a coordination reaction between the metal ions and organic ligands is utilized to form a porous metal organic framework on the fiber, thereby obtaining the functional fiber. The functional fiber contains active metal sites and can adsorb hydrogen sulfide gas. Meanwhile, the functional fiber has a porous structure, so that the adsorption capacity of hydrogen sulfide gas can be further improved. When the functional fiber is used for adsorbing hydrogen sulfide gas, the fiber material itself has excellent hydrogen sulfide gas adsorption performance, and it is not necessary to perform alkali and oxide pretreatment loading before adsorption.

Description

Technical Field

[0001] This invention relates to the field of adsorption materials technology, and in particular to a functional fiber, its preparation method, and its application in the adsorption of hydrogen sulfide gas. Background Technology

[0002] Hydrogen sulfide is a weakly acidic, highly irritating gas with a strong rotten egg smell. The presence of hydrogen sulfide in the gas can not only cause corrosion of equipment and pipelines and catalyst poisoning, but also seriously threaten personal safety.

[0003] Both wet methods (absorption and absorption-oxidation) and the Claus oxidation method for producing acid are suitable for high-concentration hydrogen sulfide gas, but not for low-concentration hydrogen sulfide gas adsorption and purification. Adsorption methods are characterized by simple equipment, easy operation, and high removal rates. Hydrogen sulfide gas adsorption materials mainly include activated carbon, zeolite, molecular sieves, and metal oxides. Traditional powdered adsorption materials are not suitable for confined spaces and can clog pipelines. Furthermore, there are many areas requiring optimization in terms of adsorption capacity and preparation conditions. Ion exchange fiber materials have advantages such as designable surface functional groups, large wire diameter ratio, short mass transfer distance, elasticity of the fiber material itself, controllable packing density, and diverse forms, making them suitable for gas treatment.

[0004] Wu Jie disclosed the performance and regeneration research of quaternary ammonium polymer-type H2S adsorbent. Using PP-ST-DVB (polypropylene-styrene-divinylbenzene) as the matrix skeleton fiber, quaternary ammonium functional groups were loaded through chloromethylation and quaternization, with chloride ions as the anion. Before adsorption, the fiber material was pre-impregnated with sodium carbonate, and the chloride ions were replaced by carbonate ions through an ion exchange reaction until the chloride ions were completely exchanged. The adsorption principle of hydrogen sulfide gas is based on an acid-base reaction mechanism, and the adsorption capacity at room temperature is 1.10 mmol / g (Wu Jie. Performance and Regeneration Research of Quaternary Ammonium Polymer-Type H2S Adsorbent [D]. Zhejiang University, 2018. DOI:CNKI:CDMD:2.1018.271939.).

[0005] Fan Zhenjiang et al. disclosed a method for adsorbing H2S from coke oven gas. PP-ST-DVB skeleton-supported quaternary ammonium functional group fibers (RCl) are pretreated with alkaline (NaOH, KOH, NaHCO3, Na2CO3, ammonia) oxidant solutions (hydrogen peroxide, potassium dichromate, potassium permanganate, NaClO, Ca(ClO)2, NaClO2) to convert the ion exchange fibers into the RClO oxidized form, thus enabling them to oxidize hydrogen sulfide gas. After adsorption saturation, the fibers are regenerated with an alkaline oxidant solution and recycled (Fan Zhenjiang, Shi Lei, Tian Erfei, et al. A method for adsorbing H2S from coke oven gas: 202110780585 [P] [2023-12-02].). The principle of hydrogen sulfide adsorption is as follows:

[0006]

[0007]

[0008] In the above studies on hydrogen sulfide adsorption, ion exchange fiber (IEF) materials mainly act as inert carriers and rely on reaction reagents to adsorb hydrogen sulfide gas. For example, inorganic bases (sodium carbonate, sodium hydroxide, etc.) and oxidants (hypochlorite) physically loaded on ion exchange fibers (IEF) undergo acid-base neutralization and redox reactions with hydrogen sulfide to remove hydrogen sulfide gas molecules. On the one hand, the preparation cost is high, and on the other hand, the adsorption capacity is not high. Summary of the Invention

[0009] The purpose of this invention is to provide a functional fiber, its preparation method, and its application in the adsorption of hydrogen sulfide gas. The functional fiber of this invention can directly adsorb hydrogen sulfide gas without relying on loaded reaction reagents, and has a high adsorption capacity for hydrogen sulfide gas with low preparation cost.

[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0011] This invention provides a method for preparing functional fibers, comprising the following steps: mixing acrylic fibers with an amination reagent solution and carrying out an amination reaction to obtain amination fibers;

[0012] The amination fiber is mixed with a metal salt solution and subjected to ion exchange to obtain a fiber loaded with metal ions; the metal salt in the metal salt solution includes one or more of copper salt, iron salt, zinc salt and zirconium salt;

[0013] The fiber loaded with metal ions is mixed with organic ligands and a polar solvent to carry out a coordination reaction, in which the metal ions and organic ligands form a porous metal-organic framework, thus obtaining functional fibers.

[0014] Preferably, the amination reagent is an organic amine; the mass content of the amination reagent in the amination reagent solution is 20-100%; and the ratio of the amount of acrylic fiber to the amination reagent solution is 1g:(5-100)mL.

[0015] Preferably, the amination reaction is carried out at a temperature of 90–140°C, for a time of 5–10 h, and at a pressure of 0.1–0.15 MPa.

[0016] Preferably, the concentration of the metal salt solution is 0.005–0.4 mol / L.

[0017] Preferably, the ratio of the amination fiber to the metal salt solution is 1g:(40-100)mL.

[0018] Preferably, the ion exchange time is 30 to 120 minutes.

[0019] Preferably, the organic ligand includes one or more of tricresylbenzene, phthalic acid, terephthalic acid, benzoic acid, EDTA acid, pyrrolidone, and chloroglycidyl; the mass ratio of the metal ion-loaded fiber to the organic ligand is 1:(0.1-2.0).

[0020] Preferably, the coordination reaction is carried out at a temperature of 80–140°C for a time of 4–48 h.

[0021] The present invention provides a functional fiber prepared by the preparation method described above, comprising acrylic fiber and a porous metal-organic framework bonded to the acrylic fiber; wherein the metal in the porous metal-organic framework is one or more of copper, iron, zinc and zirconium.

[0022] This invention provides the application of the functional fiber described above as an adsorbent in the adsorption of hydrogen sulfide gas.

[0023] This invention provides a method for preparing functional fibers, comprising the following steps: mixing acrylic fibers with an amination reagent solution to perform an amination reaction, obtaining amination fibers; mixing the amination fibers with a metal salt solution to perform ion exchange, obtaining fibers loaded with metal ions; the metal salt in the metal salt solution includes one or more of copper salts, iron salts, zinc salts, and zirconium salts; mixing the fibers loaded with metal ions with organic ligands and a polar solvent to perform a coordination reaction, whereby the metal ions and organic ligands form a porous metal-organic framework, obtaining functional fibers. This invention first aminations the acrylic fibers to load them with amino functional groups, giving them anion exchange properties (amino functional groups are basic, while metal ions are soft acids, allowing for acid-base neutralization); then, metal ion exchange is performed to load metal ions onto the fibers; finally, the coordination reaction between the metal ions and organic ligands forms a porous metal-organic framework on the fibers, obtaining functional fibers. The functional fibers of this invention contain active metal sites that can adsorb hydrogen sulfide gas, and their porous structure further enhances the adsorption capacity of hydrogen sulfide gas.

[0024] When the functional fibers of the present invention are used for the adsorption of hydrogen sulfide gas, there is no need for pretreatment with alkali and oxides before adsorption, and the functional fiber material itself has excellent hydrogen sulfide gas adsorption performance.

[0025] Furthermore, this invention uses acrylic fiber as raw material, which is inexpensive and readily available. The reaction conditions for preparing functional fibers are mild, and the equipment requirements are relatively low.

[0026] This invention also solves the problems of large pressure difference and powder clogging of pipelines during the adsorption process of powdered adsorbents. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of static adsorption.

[0028] Figure 2 SEM image of the functional fiber prepared in Example 1;

[0029] Figure 3 XRD patterns of Cu-BTC (a) prepared by the existing hydrothermal method and functional fiber (b) prepared in Example 1. Detailed Implementation

[0030] This invention provides a method for preparing functional fibers, comprising the following steps: mixing acrylic fibers with an amination reagent solution and carrying out an amination reaction to obtain amination fibers;

[0031] The amination fiber is mixed with a metal salt solution and subjected to ion exchange to obtain a fiber loaded with metal ions; the metal salt in the metal salt solution includes one or more of copper salt, iron salt, zinc salt and zirconium salt;

[0032] The fiber loaded with metal ions is mixed with organic ligands and a polar solvent to carry out a coordination reaction, in which the metal ions and organic ligands form a porous metal-organic framework, thus obtaining functional fibers.

[0033] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.

[0034] This invention involves mixing acrylic fibers with an amination reagent solution to carry out an amination reaction, thereby obtaining amination fibers.

[0035] This invention does not have any special requirements for the acrylic fiber used; any acrylic fiber well-known in the art can be used. In the embodiments of this invention, the acrylic fiber is a commercially available cotton-type acrylic fiber with a specification of 1.66 denier and a fiber length of 38 mm.

[0036] In this invention, the amination reagent solution is preferably obtained by dissolving the amination reagent in a solvent; the amination reagent is preferably an organic amine, and the specific type of organic amine used in this invention is not particularly required; any well-known organic amine capable of amination is acceptable, such as N,N-dimethylethylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylenehexamine, and polyethyleneimine; in the embodiments of this invention, specifically triethylenetetramine and polyethyleneimine are used, with a mass ratio of triethylenetetramine to polyethyleneimine of 3:1; the solvent is preferably a polar solvent, more preferably one or more of deionized water, ethanol, ethylene glycol, N,N-dimethylformamide, dimethyl sulfoxide, and thionyl chloride. In this invention, the mass content of the amination reagent in the amination reagent solution is preferably 20% to 100%.

[0037] In this invention, the preferred ratio of the amount of acrylic fiber to the amination reagent solution is 1g:(5-100)mL, more preferably 1g:(20-80)mL, and even more preferably 1g:(40-60)mL.

[0038] In this invention, the temperature of the amination reaction is preferably 90–140°C, more preferably 100–130°C, and even more preferably 110–120°C; the time of the amination reaction is preferably 5–10 h, more preferably 6–9 h, and even more preferably 7–8 h; the pressure of the amination reaction is preferably 0.1–0.15 MPa. During the amination reaction, the cyano groups on the acrylic fiber undergo amination, thereby loading the fiber with amino functional groups and giving it anion exchange capacity. In this invention, the anion exchange capacity of the amination fiber is preferably 3–6 mmol / g.

[0039] After the amination reaction is completed, the present invention preferably centrifuges and spins the obtained fiber, washes it with water until the pH value of the washing solution is 7, and dries it at 60°C to obtain the amination fiber.

[0040] After obtaining the amination fiber, the present invention mixes the amination fiber with a metal salt solution and performs ion exchange to obtain a fiber loaded with metal ions.

[0041] In this invention, the metal salt in the metal salt solution includes one or more of copper salts, iron salts, zinc salts, and zirconium salts; the copper salt preferably includes one or more of copper nitrate, copper sulfate, and copper chloride; the iron salt preferably includes ferric nitrate; the zinc salt preferably includes zinc nitrate; and the zirconium salt preferably includes zirconium chloride. In this invention, the metal salt solution is preferably obtained by dissolving the metal salt in water. In this invention, the concentration of the metal salt solution is preferably 0.005–0.4 mol / L, more preferably 0.01–0.35 mol / L, further preferably 0.1–0.3 mol / L, and even more preferably 0.15–0.25 mol / L.

[0042] In this invention, the ratio of the amination fiber to the metal salt solution is 1 g:(40-100) mL, more preferably 1 g:(50-80) mL, and even more preferably 1 g:(60-70) mL. In this invention, the ion exchange time is preferably 30-120 min, more preferably 60-100 min; the ion exchange is preferably carried out under ambient temperature shaking conditions. This invention loads metal ions onto acrylic fibers via ion exchange.

[0043] After the ion exchange is completed, the present invention preferably dries the obtained fibers at 60-80°C for 3-5 hours to obtain fibers loaded with metal ions.

[0044] After obtaining the metal ion-loaded fiber, the present invention mixes the metal ion-loaded fiber with an organic ligand and a polar solvent to carry out a coordination reaction, in which the metal ions and the organic ligand form a porous metal-organic framework to obtain a functional fiber.

[0045] In this invention, the organic ligand preferably includes one or more of tricresylbenzene, phthalic acid, terephthalic acid, benzoic acid, EDTA acid, pyrrolidone, and chloroglycidyl; the mass ratio of the metal ion-loaded fiber to the organic ligand is preferably 1:(0.1-2.0), more preferably 1:(0.5-1.5), and even more preferably 1:(0.8-1.2). In this invention, the polar solvent is preferably one or more of water, polyvinylpyrrolidone, anhydrous ethanol, N,N-dimethylformamide (DMF), dimethyl sulfoxide, and dichloroethane, more preferably water, anhydrous ethanol, and N,N-dimethylformamide. When water, anhydrous ethanol, and N,N-dimethylformamide are used, the three are preferably in equal mass ratios. In this invention, the mass ratio of the metal ion-loaded fiber to the polar solvent is preferably 1:(10-80), more preferably 1:(40-60).

[0046] The present invention does not have special requirements for the mixing process; a mixing process well known in the art can be used. In this invention, the temperature of the coordination reaction is preferably 80–140°C, more preferably 90–130°C, and even more preferably 100–120°C; the time of the coordination reaction is preferably 4–48 h, more preferably 10–40 h, and even more preferably 20–30 h. During the coordination reaction process, the metal ions and organic ligands form a porous metal-organic framework.

[0047] After the coordination reaction is completed, the resulting fibers are centrifuged and dried at 60°C to obtain functional fibers.

[0048] This invention provides a functional fiber prepared by the method described above, comprising acrylic fibers and a porous metal-organic framework bonded to the acrylic fibers; the metal in the porous metal-organic framework is one or more of copper, iron, zinc, and zirconium. The functional fiber of this invention contains active metal sites, enabling it to adsorb hydrogen sulfide gas, and its porous structure further enhances the adsorption capacity of hydrogen sulfide gas.

[0049] This invention provides the application of the functional fiber described above as an adsorbent in the adsorption of hydrogen sulfide gas.

[0050] The functional fibers provided by the present invention, their preparation method, and their application in the adsorption of hydrogen sulfide gas are described in detail below with reference to the embodiments. However, these should not be construed as limiting the scope of protection of the present invention.

[0051] Example 1

[0052] Experiment on the preparation of functional fibers:

[0053] (1) Acrylic fiber (1.66D, 38mm) was mixed with an aqueous solution of triethylenetetramine and polyethyleneimine (wherein, the mass content of triethylenetetramine was 15% and the mass content of polyethyleneimine was 5%) at a ratio of 1g:100mL, and the amination reaction was carried out at 110℃ for 6h. The resulting fiber was centrifuged and dried, washed with water until the pH of the washing solution was 7, and dried at 60℃ to obtain amination fiber.

[0054] (2) The aminated fiber was mixed with copper nitrate aqueous solution (concentration of 0.22mol / L) at a ratio of 1g:100mL, and the mixture was shaken at room temperature for 1h for ion exchange. The mixture was then spun dry and dried at 60℃ to obtain copper-loaded fiber.

[0055] (3) The copper-loaded fiber, pyromellitic acid, DMF, ethanol and water were mixed in a mass ratio of 1.0:0.40:20:20:20 and subjected to a coordination reaction at 120°C for 24 hours. The mixture was then spun dry and dried at 60°C to obtain the functional fiber. The final fiber weight gain was 60.20%.

[0056] The functional fibers of Example 1 were observed by scanning electron microscopy, and the results are as follows: Figure 2 As shown, by Figure 2 It can be seen that the fiber surface is covered with crystals. Further XRD characterization of the functional fiber of Example 1 was performed and compared with Cu-BTC prepared by the hydrothermal method in the prior art. The results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the Cu-BTC prepared by hydrothermal method has similar diffraction absorption peaks to the functional fibers prepared in this invention, indicating that the functional fibers of this invention contain Cu-MOF structures.

[0057] Example 2

[0058] Experiment on the preparation of functional fibers:

[0059] (1) Same as Example 1;

[0060] (2) The aminated fiber was mixed with a mixed aqueous solution of copper nitrate and zinc nitrate (each with a concentration of 0.22 mol / L) at a ratio of 1 g: 100 mL. The mixture was shaken at room temperature for 1 h for ion exchange, spun dry, and dried at 60 °C to obtain the fiber loaded with copper and zinc ions.

[0061] (3) The copper and zinc ion-loaded fibers, pyromellitic acid, DMF, ethanol and water were mixed in a mass ratio of 1.0:0.40:20:20:20 and subjected to a coordination reaction at 120°C for 24 hours. The mixture was then spun dry and dried at 60°C to obtain functional fibers with a final fiber weight gain of 62.41%.

[0062] Example 3

[0063] Experiment on the preparation of functional fibers:

[0064] (1) Acrylic fiber (1.66D, 38mm) was mixed with an aqueous solution of triethylenetetramine and polyethyleneimine (wherein, the mass content of triethylenetetramine was 15% and the mass content of polyethyleneimine was 5%) at a ratio of 1g:100mL, and the amination reaction was carried out at a temperature of 120℃ for 6h. The resulting fiber was centrifuged and dried, washed with water until the pH of the washing solution was 7, and dried at 60℃ to obtain the amination fiber.

[0065] (2) The aminated fiber was mixed with a mixed aqueous solution of copper nitrate and zinc nitrate (each with a concentration of 0.22 mol / L) at a ratio of 1 g: 100 mL. The mixture was shaken at room temperature for 1 h for ion exchange, spun dry, and dried at 60 °C to obtain fiber loaded with copper and zinc ions.

[0066] (3) The copper and zinc loaded fibers, pyromellitic acid, polyvinylpyrrolidone, DMF, ethanol and water were mixed in a mass ratio of 1.0:0.40:0.2:20:20:20 and subjected to a coordination reaction at 120°C for 24 hours. The mixture was then spun dry and dried at 60°C to obtain functional fibers with a final fiber weight gain of 62.55%.

[0067] Comparative Example 1

[0068] Acrylic fiber (1.66D, 38mm) was mixed with an aqueous solution of triethylenetetramine and polyethyleneimine (wherein the mass content of triethylenetetramine was 15% and the mass content of polyethyleneimine was 5%) at a ratio of 1g:100mL, and the mixture was subjected to an amination reaction at 120℃ for 6h. The resulting fiber was centrifuged, washed with water until the pH of the washing solution was 7, and dried at 60℃ to obtain the amination fiber; the ion exchange capacity was 5-6 mmol / g.

[0069] Comparative Example 2

[0070] Aminocellulose was impregnated with NaOH. 0.3g of Comparative Example 1 aminated fiber was weighed and impregnated with NaOH at a mass ratio of 1g:100mL of aminated fiber to sodium hydroxide solution (mass concentration 3%). After centrifugation, excess solution was removed with filter paper, and the load increased by 80%.

[0071] Comparative Example 3

[0072] The preparation of acrylic-based activated carbon fiber follows a pre-oxidation-carbonization-KOH activation process, as detailed below:

[0073] (1) Pre-oxidation: Acrylic fiber (1.66D, 38mm) was placed in a tube furnace, pre-oxidation temperature was 250℃, air flow rate was 50mL / min, and time was 1.0h;

[0074] (2) Carbonize at 900℃, nitrogen flow rate 100mL / min, time 0.5h to obtain carbonized fiber;

[0075] (3) Activation: Carbonized fiber and KOH solution (50% mass concentration) were mixed at a ratio of 1:10 (by weight), shaken for 24 hours, and then the fiber was placed in a tube furnace for activation at 800℃ and nitrogen flow rate of 100 mL / min for 1.0 hour. The resulting fiber was designated PAN-ACF. The BET specific surface area was determined to be 1366 m² / g by physical adsorption method. 2 / g, with an average pore size of 1.0167nm.

[0076] Comparative Example 4

[0077] The only difference from Example 1 is that step (3) is omitted.

[0078] Performance testing

[0079] In the static adsorption experiment of hydrogen sulfide gas, 0.3 g of each of the following fibers were weighed: Comparative Example 1 aminated fiber, Comparative Example 2 aminated fiber loaded with 80% NaOH, Comparative Example 3 PAN-ACF, and the functional fiber of Example 1. These were placed in sealed gas bags and filled with a prepared mixture of hydrogen sulfide and nitrogen gas of a certain volume. Figure 1 As shown, the adsorption time was 4 hours. The initial and final residual hydrogen sulfide gas concentrations were tested according to GB / T11060.1-2010 (Determination of sulfur compounds in natural gas, Part I: Determination of hydrogen sulfide content by iodometric titration). The adsorption capacity was calculated according to Formula 1, and the results are shown in Table 1.

[0080]

[0081] In Formula 1: Q, gas adsorption capacity, mg / g; C0, initial gas concentration, mg / m³. 3 C e Final gas concentration after adsorption, mg / m³ 3 V, gas volume, m 3 m, adsorbent weight, g.

[0082] Table 1. Adsorption capacity (mg / g) of fibers in the examples and comparative examples

[0083]

[0084] As shown in Table 1, the functional fiber of the present invention exhibits a larger hydrogen sulfide gas adsorption capacity compared with the amino anion exchange fiber (Comparative Example 1), the amino anion exchange fiber impregnated with sodium hydroxide solution (Comparative Example 2), PAN-ACF (KOH activated Comparative Example 3), and the functional fiber omitting the coordination reaction (Comparative Example 4).

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing functional fibers for adsorbing hydrogen sulfide gas, characterized in that, Includes the following steps: Acrylic fibers are mixed with an amination reagent solution and subjected to an amination reaction to obtain amination fibers; the amination reagent is triethylenetetramine and polyethyleneimine, and the mass ratio of triethylenetetramine to polyethyleneimine is 3:

1. The amination fiber was mixed with a copper nitrate solution and subjected to ion exchange to obtain copper-loaded fiber. The copper-loaded fiber is mixed with an organic ligand and a polar solvent to carry out a coordination reaction. The copper ions and the organic ligand form a porous copper organic framework, resulting in a functional fiber for adsorbing hydrogen sulfide gas. The organic ligand is benzoic acid; the mass ratio of the copper-loaded fiber to the organic ligand is 1:(0.1~2.0). The polar solvent is water, anhydrous ethanol, and N,N-dimethylformamide; the mass ratio of water, anhydrous ethanol, and N,N-dimethylformamide is 1:1:

1.

2. The preparation method according to claim 1, characterized in that, The mass content of the amination reagent in the amination reagent solution is 20%; the ratio of the amount of acrylic fiber to the amination reagent solution is 1g:(5~100)mL.

3. The preparation method according to claim 1 or 2, characterized in that, The amination reaction is carried out at a temperature of 90~140℃ for 5~10h and at a pressure of 0.1~0.15MPa.

4. The preparation method according to claim 1, characterized in that, The concentration of the copper nitrate solution is 0.005~0.4 mol / L.

5. The preparation method according to claim 1 or 4, characterized in that, The ratio of the amount of amination fiber to copper nitrate solution is 1g:(40~100)mL.

6. The preparation method according to claim 1 or 4, characterized in that, The ion exchange time is 30~120 min.

7. The preparation method according to claim 1, characterized in that, The coordination reaction is carried out at a temperature of 80~140℃ for a time of 4~48h.

8. The functional fiber for adsorbing hydrogen sulfide gas prepared by the preparation method according to any one of claims 1 to 7 comprises acrylic fiber and a porous copper organic framework bonded to the acrylic fiber.

9. The application of the functional fiber of claim 8 as an adsorbent in the adsorption of hydrogen sulfide gas.

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