Triazine composite desulfurizer and preparation method thereof

Abstract

The invention discloses a triazine composite desulfurizer and a preparation method thereof, and relates to the technical field of gas purification. The desulfurizing agent is prepared by taking s-triazine and a metal oxide-activated carbon compound as active main bodies, and compounding with hexahydro-1, 3, 5-tris (hydroxyethyl)-s-triazine, a surfactant, a catalyst, an anticorrosive agent and a scale inhibitor. Carrying out nucleophilic reaction on s-triazine and S atoms in H2S to remove inorganic sulfur; according to the metal oxide-activated carbon compound, activated carbon serves as a porous carrier, the high specific surface area provides rich adsorption sites, mercaptan organic sulfur molecules are adsorbed to the surface of the carrier, sulfur elements are combined with metal ions, a metal sulfide product is formed, and capture and removal of mercaptan organic sulfur are achieved. The surfactant in the desulfurizing agent optimizes the dispersity of the system, the catalyst accelerates desulfurization and inhibits precipitation, the anticorrosive agent maintains a weakly alkaline environment, and the scale inhibitor inhibits generation of inorganic salt scale. The desulfurizing agent solves the problems that a traditional desulfurizing agent is prone to generating sediment, corroding equipment, scaling and blocking and the like.

Description

Technical Field

[0001] This application relates to the field of gas purification technology, and more specifically, to a triazine composite desulfurizing agent and its preparation method. Background Technology

[0002] With the continuous expansion of global industrial production and the adjustment of energy consumption structure, the emission of sulfur-containing gases such as industrial waste gas and chemical tail gas has increased significantly. Sulfides in sulfur-containing gases (including inorganic sulfur such as hydrogen sulfide and organic sulfur such as methanethiol) have become one of the important sources of air pollution. These sulfides not only form acid rain, damaging the ecological environment, harming crop growth and soil quality, but also cause serious corrosion to industrial production equipment and pipelines, shortening equipment lifespan, increasing safety hazards, and affecting product quality in subsequent processing, which does not meet the current environmental protection requirements of green development and pollution reduction.

[0003] Currently, triazine desulfurizers are widely used in industrial waste gas desulfurization and chemical tail gas purification due to their mild reaction conditions, high selectivity, and easy product separation. However, in practical applications, facing the complex conditions of high sulfur, high humidity, high temperature, and multiphase media coexisting in industrial production, existing triazine desulfurizers still have many areas for improvement: precipitation can easily lead to pipeline blockage during desulfurization system operation, affecting the continuity of the desulfurization process; the system stability is insufficient, and desulfurization efficiency is prone to decline when operating conditions fluctuate; the corrosion protection effect on equipment is limited, and long-term use will increase equipment maintenance costs; at the same time, some desulfurizers have poor compatibility with sulfur-containing media, and mass transfer efficiency needs to be improved, which restricts further optimization of desulfurization performance and makes it difficult to meet strict pollution control emission standards.

[0004] Therefore, for the complex desulfurization conditions in industrial pollution control, developing a desulfurizing agent preparation technology that is highly stable, adaptable, and can balance desulfurization efficiency and system protection functions is of great practical value for advancing pollution control and reducing environmental risks. Summary of the Invention

[0005] The purpose of this application is to provide a triazine composite desulfurizer and its preparation method, so as to optimize the application performance of the desulfurizer under complex working conditions and improve the stability and reliability of the desulfurization system.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] In a first aspect, this application provides a method for preparing a triazine composite desulfurizing agent, comprising the following steps:

[0008] S1. Add the surfactant to deionized water, then disperse it by ultrasonication to obtain a surfactant solution;

[0009] S2. Add triazine and hydroxyethyl hexahydrotriazine to the surfactant solution, stir and react to obtain a triazine mixture;

[0010] S3. Next, add the metal oxide-activated carbon complex, catalyst, corrosion inhibitor, and scale inhibitor in sequence, and then continue stirring to obtain the triazine composite desulfurizer;

[0011] The metal oxide-activated carbon composite is prepared from metal oxide and activated carbon.

[0012] Furthermore, the preparation of the metal oxide-activated carbon composite includes the following steps:

[0013] The metal oxide and activated carbon were dispersed in anhydrous ethanol, sonicated for 30-45 min, stirred at 50-60℃ for 2-3 h, filtered, and then dried at 60-80℃ for 4-5 h to obtain the metal oxide-activated carbon composite.

[0014] Furthermore, the metal oxides include ZnO or CuO; the specific surface area of ​​the activated carbon is 1000-1200 m². 2 / g; the particle size of ZnO is 15-30nm, and the particle size of CuO is 25-40nm.

[0015] Furthermore, the mass ratio of metal oxide to activated carbon is 1:(5-8).

[0016] Furthermore, in S1, the temperature of the deionized water is 50-60℃; the ultrasonic dispersion time is 10-15 min.

[0017] Furthermore, in S2, the stirring reaction is carried out at a temperature of 60-80°C for 30-45 minutes and at a speed of 300-400 rpm.

[0018] Furthermore, in S1, the surfactant includes disodium lauryl citrate sulfosuccinate or sodium dodecylbenzene sulfonate; in S3, the catalyst includes zinc glycolate or zinc hydroxychloride; the corrosion inhibitor includes morpholine or N-methylmorpholine; and the scale inhibitor includes calcium hydroxyphosphate or magnesium hydroxyphosphate.

[0019] Furthermore, in S3, the stirring time is 30-60 minutes and the speed is 400-600 rpm.

[0020] Furthermore, the mass ratio of triazine, metal oxide-activated carbon complex, surfactant, hydroxyethyl hexahydrotriazine, catalyst, corrosion inhibitor, scale inhibitor and deionized water is (10-15): (5-10): (10-15): (5-10): (10-15): (5-8): (2-3): (24-53).

[0021] Secondly, this application provides a triazine composite desulfurizer prepared using the preparation method described in the first aspect.

[0022] The nitrogen atom in the triazine ring contains a lone pair of electrons that do not participate in conjugation and has a higher electronegativity than the carbon atom. This causes the electron cloud in the ring to shift towards the nitrogen atom, which becomes negatively charged. This nitrogen atom then undergoes a nucleophilic reaction with the sulfur atom in H₂S, converting H₂S into triazine thiols, thus achieving the removal of inorganic sulfur. Furthermore, the metal oxide-activated carbon composite uses activated carbon as a porous support. Its high specific surface area provides abundant adsorption sites, adsorbing thiol-type organic sulfur molecules onto the support surface. These thiol-type organic sulfur molecules contain SH bonds, which react with Lewis base sites (O₂, O₂, and SH) on the metal oxide surface. 2- The sulfur-containing anions and hydroxyl groups interact to form sulfur-containing anions and hydroxyl groups. Subsequently, the sulfur-containing anions combine with Lewis acid sites on the surface of metal oxides to form metal thiolate intermediates. The metal thiolate further undergoes bond cleavage, with alkyl groups desorbing into small hydrocarbon molecules, while sulfur combines with metal ions to form metal sulfide products, thus achieving the capture and removal of thiol-type organic sulfur. The combined action of triazine and the metal oxide-activated carbon complex achieves the purpose of removing both thiol-type organic sulfur molecules and inorganic sulfur.

[0023] The hydroxyethyl hexahydrotriazine molecule contains a hydroxyethyl substituent, and the hydroxyethyl group includes a hydrophilic hydroxyl group. The presence of the hydroxyl group enhances the hydrophilicity of the reaction system and improves the contact efficiency between the active component and the sulfur-containing medium. The introduction of surfactants further optimizes the lipophilic-hydrophilic balance of the system, reduces the gas-liquid interfacial tension, promotes the uniform dispersion of the desulfurizer in multiphase media such as oil and gas and waste gas, and expands the contact area between the active component and sulfides, laying the foundation for efficient desulfurization.

[0024] Multiple auxiliary components enhance system stability through functional complementarity: Metal ions in the catalyst can complex with triazine thiols generated from the reaction of triazine rings with sulfides, thereby accelerating the reaction process. Simultaneously, the metal ions, through complexation with the reaction intermediates, restrict the free diffusion and contact of the intermediates, preventing polymerization reactions that generate insoluble solid precipitates such as dithiazide polymers, thus preventing pipeline blockage and ensuring stable flow in the desulfurization system. The corrosion inhibitor, as an organic base, contains amino groups with lone pairs of electrons in its molecular structure, which can combine with hydrogen ions generated during the desulfurization reaction, buffering pH fluctuations and preventing desulfurizer decomposition caused by an acidic environment. The functional groups such as phosphate groups in scale inhibitor molecules coordinate with cations such as calcium and magnesium ions in the desulfurization system, preventing the cations from directly combining with sulfate and carbonate ions to form insoluble inorganic salt crystals such as calcium sulfate and calcium carbonate. Simultaneously, the polar functional groups in scale inhibitor molecules, such as phosphate and hydroxyl groups, have surface charges or strong adsorption activity. During the growth of inorganic salt crystals such as calcium sulfate and calcium carbonate, active growth sites with corresponding charges or polarities are formed on the crystal surface. Based on charge attraction and intermolecular forces, scale inhibitor molecules act on the active growth sites of inorganic salt crystals, occupying key positions for crystal growth and disrupting the normal lattice arrangement and growth pattern of the crystals, preventing the formation of inorganic salts. This inhibits the precipitation and deposition of inorganic salt scale from the source, preventing scale buildup and blockage inside pipes and equipment from interfering with the lattice growth of inorganic salt scale and ensuring smooth system flow.

[0025] Beneficial technical effects:

[0026] The application discloses a triazine composite desulfurizer and its preparation method, comprising a triazine component, a metal oxide-activated carbon composite, and auxiliary components. The nitrogen atom on the triazine molecule ring contains lone pairs of electrons that do not participate in conjugation. These electrons undergo a nucleophilic reaction with the sulfur atom in H2S, converting H2S into triazine thiols and thus removing inorganic sulfur. The metal oxide-activated carbon composite uses activated carbon as a porous carrier. Its high specific surface area provides abundant adsorption sites, adsorbing thiol-type organic sulfur onto the carrier surface. Sulfur combines with metal ions to form metal sulfide products, achieving the capture and removal of thiol-type organic sulfur. The hydroxyethyl substituent of hydroxyethyl hexahydrotriazine enhances the hydrophilicity of the active system. The surfactant further optimizes the lipophilic-hydrophilic balance, reduces the gas-liquid interfacial tension, and improves the contact efficiency between the active component and the sulfur-containing medium. The metal ions in the catalyst accelerate the desulfurization reaction process by forming complexes with desulfurization intermediates and restrict the free diffusion of intermediates to avoid polymerization and precipitation. The corrosion inhibitor acts as an organic base, maintaining the weakly alkaline environment required for the desulfurization reaction. The scale inhibitor inhibits the precipitation of inorganic salts under high sulfur conditions through the interaction of phosphate ions and metal ions, while also enhancing the overall chemical stability of the solution. The components work together to solve the problems of precipitation, equipment corrosion and scaling blockage that traditional desulfurizing agents cause in pollution control, and provide a technical solution for the pollution control of sulfur-containing gases such as industrial waste gas and chemical tail gas. Attached Figure Description

[0027] Figure 1 This is a flowchart of a preparation method for a triazine composite desulfurizing agent. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, a detailed description is provided below in conjunction with specific embodiments of this application.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides a triazine composite desulfurizer and its preparation method, the preparation method including the following steps:

[0032] S1. Disodium lauryl citrate sulfosuccinate was added to deionized water at 50°C and ultrasonically dispersed for 10 min to obtain a surfactant solution;

[0033] S2. Add triazine and hydroxyethyl hexahydrotriazine to the surfactant solution, heat to 60℃ and stir at 300 rpm for 30 min to obtain a triazine mixture;

[0034] S3. Next, add ZnO-activated carbon complex, zinc glycolate, N-methylmorpholine, and calcium hydroxyphosphate sequentially, and then continue stirring at 400 rpm for 30 min to obtain triazine composite desulfurizer; wherein, the preparation steps of ZnO-activated carbon complex include: taking ZnO with a particle size of 15 nm and a specific surface area of ​​1000 m² 2 / g of activated carbon was dispersed in anhydrous ethanol at a mass ratio of 1:5, sonicated for 30 min, stirred at 50℃ for 2 h, filtered, and then dried at 60℃ for 4 h to obtain the ZnO-activated carbon composite.

[0035] The mass ratio of triazine, ZnO-activated carbon complex, disodium lauryl citrate sulfosuccinate, hydroxyethyl hexahydrotriazine, zinc glycolate, N-methylmorpholine, calcium hydroxyphosphate, and deionized water is 10:5:10:5:10:5:2:53.

[0036] Example 2

[0037] like Figure 1 As shown, this embodiment provides a triazine composite desulfurizer and its preparation method, the preparation method including the following steps:

[0038] S1. Sodium dodecylbenzenesulfonate was added to deionized water at 60°C and ultrasonically dispersed for 15 min to obtain a surfactant solution;

[0039] S2. Add triazine and hydroxyethyl hexahydrotriazine to the surfactant solution, heat to 80℃ and stir at 400 rpm for 45 min to obtain a triazine mixture;

[0040] S3. Next, CuO-activated carbon complex, zinc hydroxychloride, morpholine, and magnesium hydroxyphosphate are added sequentially, and then stirred at 600 rpm for 60 min to obtain triazine composite desulfurizer; wherein, the preparation steps of CuO-activated carbon complex include: taking CuO with a particle size of 40 nm and a specific surface area of ​​1200 m² / m³. 2 / g of activated carbon was dispersed in anhydrous ethanol at a mass ratio of 1:8, sonicated for 45 min, stirred at 60℃ for 3 h, filtered, and then dried at 80℃ for 5 h to obtain CuO-activated carbon composite.

[0041] The mass ratio of triazine, CuO-activated carbon complex, sodium dodecylbenzenesulfonate, hydroxyethyl hexahydrotriazine, zinc hydroxychloride, morpholine, magnesium hydroxyphosphate and deionized water is 15:10:15:10:15:8:3:24.

[0042] Example 3

[0043] like Figure 1 As shown, this embodiment provides a triazine composite desulfurizer and its preparation method, the preparation method including the following steps:

[0044] S1. Disodium lauryl citrate sulfosuccinate was added to deionized water at 55°C and ultrasonically dispersed for 12.5 min to obtain a surfactant solution;

[0045] S2. Add triazine and hydroxyethyl hexahydrotriazine to the surfactant solution, heat to 70°C, stir at 350 rpm for 37.5 min to obtain a triazine mixture;

[0046] S3. Next, add ZnO-activated carbon complex, zinc glycolate, morpholine, and calcium hydroxyphosphate sequentially, and then continue stirring at 500 rpm for 45 min to obtain triazine composite desulfurizer; wherein, the preparation steps of ZnO-activated carbon complex include: taking ZnO with a particle size of 22 nm and a specific surface area of ​​1100 m² 2 / g of activated carbon was dispersed in anhydrous ethanol at a mass ratio of 1:6.5, sonicated for 37.5 min, stirred at 55℃ for 2.5 h, filtered, and then dried at 70℃ for 4.5 h to obtain the ZnO-activated carbon composite.

[0047] The mass ratio of triazine, ZnO-activated carbon complex, disodium lauryl citrate sulfosuccinate, hydroxyethyl hexahydrotriazine, zinc glycolate, morpholine, calcium hydroxyphosphate, and deionized water is 12.5:7.5:10:7.5:12.5:6.5:2.5:41.

[0048] Example 4

[0049] like Figure 1 As shown, this embodiment provides a triazine composite desulfurizer and its preparation method, the preparation method including the following steps:

[0050] S1. Sodium dodecylbenzenesulfonate was added to deionized water at 53°C and ultrasonically dispersed for 11 min to obtain a surfactant solution;

[0051] S2. Add triazine and hydroxyethyl hexahydrotriazine to the surfactant solution, heat to 80℃, stir at 320 rpm for 33 min to obtain a triazine mixture;

[0052] S3. Next, CuO-activated carbon complex, zinc hydroxychloride, N-methylmorpholine, and magnesium hydroxyphosphate are added sequentially, and then stirred at 480 rpm for 40 min to obtain triazine composite desulfurizer; wherein, the preparation steps of CuO-activated carbon complex include: taking CuO with a particle size of 32 nm and a specific surface area of ​​1150 m² / m³. 2 / g of activated carbon was dispersed in anhydrous ethanol at a mass ratio of 1:7, sonicated for 35 min, stirred at 50℃ for 2.2 h, filtered, and then dried at 75℃ for 4.2 h to obtain CuO-activated carbon composite.

[0053] The mass ratio of triazine, CuO-activated carbon complex, sodium dodecylbenzenesulfonate, hydroxyethyl hexahydrotriazine, zinc hydroxychloride, N-methylmorpholine, magnesium hydroxyphosphate, and deionized water is 11:6:10:6:11:5.5:2.3:48.2.

[0054] Comparative Example 1

[0055] Comparative Example 1 provides a triazine composite desulfurizer and its preparation method. Compared with Example 1, no triazine was added in S2 in Comparative Example 1, but the other steps and parameters were the same as in Example 1.

[0056] Comparative Example 2

[0057] Comparative Example 2 provides a triazine composite desulfurizer and its preparation method. Compared with Example 1, Comparative Example 2 does not add metal oxide-activated carbon composite in S3, while other steps and parameters are the same as in Example 1.

[0058] The performance of the triazine composite desulfurizers prepared in Examples 1-4 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0059] Table 1. Test results of the triazine composite desulfurizers prepared in Examples 1-4 and Comparative Examples 1-2

[0060]

[0061] The triazine composite desulfurizers prepared in Examples 1-4 exhibit the following characteristics: inorganic sulfur removal rate between 95.2% and 99.3%, thiol organic sulfur removal rate maintained at 90.5%-96.8%, corrosion inhibition rate reaching 46.0%-58.6%, scale inhibition rate at 82.4%-91.2%, and no precipitation formation during the desulfurization process. Triazine acts as the core for inorganic sulfur removal; the lone pair electrons of the N atom on its molecular ring undergo a nucleophilic reaction with the S atom in H2S, efficiently converting inorganic sulfur into soluble triazine thiolates. The metal oxide-activated carbon composite uses activated carbon as a porous carrier, with its high specific surface area providing abundant adsorption sites, adsorbing thiol organic sulfur molecules onto the carrier surface. Sulfur combines with metal ions to form metal sulfide products, achieving the capture and removal of thiol organic sulfur. Together, they achieve the purpose of removing both thiol organic sulfur molecules and inorganic sulfur. The hydroxyethyl hexahydrotriazine... Substituents enhance the hydrophilicity of the active system, and the optimized lipophilic-hydrophilic balance achieved with surfactants improves the contact efficiency between the active components and the sulfur-containing medium. Metal ions in the catalyst, by complexing with reaction intermediates, both lower the activation energy of the desulfurization reaction to accelerate the process and restrict the free diffusion of intermediates to prevent polymerization and precipitation. The corrosion inhibitor, acting as an organic base, maintains the weak alkalinity of the system, ensuring the stability of the desulfurizer's activity. The scale inhibitor forms unstable complexes with cations through groups such as phosphate, while simultaneously disrupting the crystal lattice growth of inorganic salts through the charge adsorption of polar functional groups. All components work together to ensure desulfurization efficiency and address the problems of system corrosion, scaling, and insufficient stability.

[0062] Comparative Example 1, lacking the addition of triazine and retaining only the metal oxide-activated carbon complex and other auxiliary components, exhibited significant performance shortcomings: the inorganic sulfur removal rate plummeted to 35.7%, and the removal rate of thiol organic sulfur dropped to 68.3%. Triazine is a key active component for inorganic sulfur removal; its absence prevents efficient H2S conversion via nucleophilic reactions, making it difficult to remove inorganic sulfur through physical adsorption alone. While the removal rate of thiol organic sulfur did not drop drastically, the disappearance of the synergistic effect between triazine and hydroxyethylhexahydrotriazine reduced the system's hydrophilicity and mass transfer efficiency, leading to a decrease in the capture efficiency of thiol organic sulfur. The corrosion inhibition rate and scale inhibition rate were also slightly weakened due to the disruption of the system's balance.

[0063] In Comparative Example 2, without the addition of the metal oxide-activated carbon complex, only triazine and other auxiliary components were retained. The removal rate of thiol-based organic sulfur plummeted to 33.6%, and precipitation occurred during the desulfurization process. The metal oxide-activated carbon complex is the core carrier for the removal of thiol-based organic sulfur. Without it, it cannot capture thiol-based organic sulfur molecules such as methanethiol. Relying solely on triazine and auxiliary components is insufficient for effective removal of thiol-based organic sulfur, leading to a decline in overall system stability and protective performance.

[0064] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.

Claims

1. A process for the preparation of a triazine complex desulfurizer characterized by, The preparation method comprises the following steps: S1. adding a surfactant into deionized water, then ultrasonic dispersion to obtain a surfactant solution; S2. adding s-triazine and hydroxyethylhexahydro-s-triazine into the surfactant solution, stirring and reacting to obtain a s-triazine mixture; S3. then sequentially adding a metal oxide-activated carbon composite, a catalyst, an anticorrosive agent and a scale inhibitor, and continuing to stir to obtain a s-triazine composite desulfurizer; The metal oxide-activated carbon composite is prepared from a metal oxide and activated carbon.

2. A process for the preparation of a triazine composite desulfurizer according to claim 1, characterized in that, The preparation of the metal oxide-activated carbon composite comprises the following steps: dispersing the metal oxide and activated carbon in anhydrous ethanol, ultrasonic dispersion for 30-45 min, then stirring at 50-60℃ for 2-3 h, filtering and drying at 60-80℃ for 4-5 h to obtain the metal oxide-activated carbon composite.

3. A process for the preparation of a triazine composite desulfurizer according to claim 2, characterized in that, The metal oxide comprises ZnO or CuO; The activated carbon has a specific surface area of 1000-1200 m 2 / g; The particle size of the ZnO is 15-30 nm, and the particle size of the CuO is 25-40 nm.

4. A process for the preparation of a triazine composite desulfurizer according to claim 2, characterized in that, The mass ratio of the metal oxide to activated carbon is 1: (5-8).

5. A process for the preparation of a triazine composite desulfurizer according to claim 1, characterized in that, In S1, the temperature of the deionized water is 50-60℃; and the ultrasonic dispersion time is 10-15 min.

6. A process for the preparation of a triazine composite desulfurizer according to claim 1, characterized in that, In S2, the stirring and reacting temperature is 60-80℃, the time is 30-45 min, and the speed is 300-400 rpm.

7. A process for the preparation of a triazine composite desulfurizer according to claim 1, characterized in that, In S3, the catalyst comprises zinc hydroxyacetate or zinc hydroxychloride; the anticorrosive agent comprises morpholine or N-methylmorpholine; and the scale inhibitor comprises calcium hydroxyphosphate or magnesium hydroxyphosphate. In S1, the surfactant comprises lauryl alcohol citrate sulfosuccinic acid disodium or sodium dodecylbenzenesulfonate.

8. A process for the preparation of a triazine composite desulfurizer according to claim 1, characterized by, In S3, the stirring time is 30-60 min, and the speed is 400-600 rpm.

9. The process for preparing a triazine composite desulfurizer according to claim 1, characterized by, The mass ratio of the s-triazine, metal oxide-activated carbon composite, surfactant, hydroxyethylhexahydro-s-triazine, catalyst, anticorrosive agent, scale inhibitor and deionized water is (10-15):(5-10):(10-15):(5-10):(10-15):(5-8):(2-3):(24-53).

10. A s-triazine composite desulfurizer prepared by the preparation method according to any one of claims 1-9.

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