An organosulfur adsorbent and a method for preparing the same

Abstract

The application relates to the field of adsorbent technology and specifically discloses an organic sulfide adsorbent and a preparation method thereof. An organic sulfide adsorbent and a preparation method thereof comprise the following steps: S1: uniformly mixing microporous molecular sieves, mesoporous molecular sieves and pseudo-boehmite, then performing kneading, molding, drying and calcination to obtain a molded body; S2: immersing the molded body in a nitrate solution A, performing temperature rising and temperature keeping, performing solid-liquid separation, drying, performing first-time calcination, immersing the molded body in a nitrate solution B, performing temperature rising and temperature keeping, performing solid-liquid separation, drying, performing second-time calcination, reducing and obtaining a loaded molded body; S3: immersing the loaded molded body in a nitric acid solution, performing pretreatment, performing solid-liquid separation, dispersing the loaded molded body in a mercapto silane solution, performing reaction, performing solid-liquid separation, dispersing the loaded molded body in a buffer solution, adding dopamine, performing reaction, performing solid-liquid separation, washing, drying and obtaining an organic sulfide adsorbent; the organic sulfide adsorbent disclosed by the application has a good removal rate for organic sulfides.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adsorbents, and more particularly to an organic sulfide adsorbent and a preparation method thereof. BACKGROUND

[0002] At present, the optimization of oil product quality has become a trend in the industry. In the light oil products produced by oil refineries in China and the oil product additive MTBE, organic sulfides such as mercaptans, sulfides, thiophene and its derivatives are generally present, among which the content of mercaptans and sulfides is relatively high, and the content of thiophene and its derivatives is second. The corrosion of these sulfides to oil refining equipment not only shortens the service life of the equipment, increases the equipment maintenance cost, but also may cause production interruption, seriously affecting the production efficiency of the oil refinery. At the same time, in the oil product combustion link, they are converted into harmful gases such as sulfur dioxide and sulfur trioxide, which not only pollute the environment, but also harm human health. For the oil product additive MTBE, these organic sulfides reduce the effect of MTBE on improving the key performance of gasoline octane number, greatly reducing the advantage of MTBE in oil product blending.

[0003] The commonly used activated carbon, molecular sieve and clay adsorbents each have obvious shortcomings. The irregularity of the pore structure of activated carbon makes it difficult to accurately capture target sulfides when adsorbing organic sulfides. Clay adsorbents are limited by limited adsorption capacity and cannot fully adsorb organic sulfides in oil products, and the regeneration process is difficult, increasing the use cost and operation complexity. Molecular sieve is a crystalline silicate or phosphosilicate with a regular pore structure. Compared with common adsorbents such as activated carbon and clay, the pore size of molecular sieve is highly uniform and precisely controllable, and has a large specific surface area and good regeneration performance. Moreover, molecular sieve has a high ion exchange capacity, and after loading transition metal ions through ion exchange, the adsorption performance of organic sulfides can be significantly enhanced.

[0004] The patent application file with publication number CN107469766A discloses an adsorbent for removing sulfides in MTBE, which comprises an active component and a carrier. The active component is a mixture of Ag2O, ZnO, Fe2O3 and La2O3, and the carrier is 13X molecular sieve. The mass ratio of the raw materials corresponding to the active component is as follows: AgNO3, the content of Ag2O is 0.0% to 10.0%; Zn(NO3)2, the content of ZnO is 0.0% to 5.0%; Fe(NO3)3, the content of Fe2O3 is 0.0% to 5.0%; La(NO3)3, the content of La2O3 is 1.0% to 5.0%; 13X molecular sieve, the balance; only one of AgNO3, Zn(NO3)2 and Fe(NO3)3 can be 0%.

[0005] In the technology, only 13X molecular sieve is used as the carrier, and the pore structure is relatively uniform and narrow. Although these micropores can provide certain adsorption sites, the number and space are limited, thereby resulting in limited adsorption capacity. Moreover, different types of sulfide molecules have different sizes and structures, and for some sulfides with large molecular size (such as thiophene and its derivatives), they are difficult to enter the narrow micropores and fully contact with the adsorption sites, thereby further reducing the removal rate of the adsorbent to the overall sulfide. SUMMARY

[0006] In order to improve the removal rate of the adsorbent to the overall organic sulfide, the present application provides an organic sulfide adsorbent and a preparation method thereof.

[0007] In a first aspect, the present application provides a preparation method of an organic sulfide adsorbent, which adopts the following technical scheme:

[0008] The preparation method of the organic sulfide adsorbent comprises the following steps:

[0009] S1: uniformly mixing 60-80 parts by mass of microporous molecular sieve, 20-40 parts by mass of mesoporous molecular sieve and 8-15 parts by mass of pseudo-boehmite, and then kneading, molding, drying and calcining to obtain a molded body;

[0010] S2: immersing the molded body in a nitrate solution A, heating to 40-60 DEG C, and keeping the temperature for 2-4 hours, then solid-liquid separation, washing, drying, first calcination, then immersing in a nitrate solution B, heating to 60-80 DEG C, keeping the temperature for 3-5 hours, then solid-liquid separation, washing, drying, second calcination, and reduction to obtain a loaded molded body;

[0011] S3: immersing the loaded molded body in a nitric acid solution, pre-treating for 10-20 minutes, then solid-liquid separation, washing, dispersing in a thiol silane solution with pH of 4-5, reacting for 6-10 hours at 20-30 DEG C, then solid-liquid separation, washing, dispersing in a buffer solution with pH of 8-9, adding 1-3 parts by mass of dopamine, reacting for 12-24 hours at 20-30 DEG C, then solid-liquid separation, washing, drying to obtain an organic sulfide adsorbent;

[0012] The nitrate solution A comprises at least two rare earth metal nitrates; and the nitrate solution B comprises at least two transition metal nitrates.

[0013] Beneficial effects: The microporous molecular sieve and mesoporous molecular sieve are compounded to form a shaped body with a multi-level pore structure, which is beneficial to the diffusion and adsorption of organic sulfides. First, immerse in a rare earth metal nitrate solution. These rare earth metal ions with large radii can form relatively large active centers and structural support points on the surface and in the pores of the carrier. Subsequently, immerse in a transition metal nitrate solution. Transition metal ions can fill the structural gaps formed by rare earth metals to construct a more complex and ordered multi-level structure. This structure design not only increases the number of active sites, but also optimizes the distribution of active sites, improves the adsorption selectivity and capacity of the adsorbent for organic sulfides.

[0014] At the same time, the step-by-step calcination method not only helps the rare earth metal nitrate to fully decompose, so that the rare earth metal oxide is firmly loaded on the shaped body, but also helps the transition metal nitrate to be uniformly deposited on the surface and in the pores of the molecular sieve, avoiding the particle growth and agglomeration phenomenon caused by high temperature. After reduction treatment, part of the metal is in elemental or intermediate valence state, which not only can enhance the adsorption performance of the subsequent organic sulfides, but also can enhance the resistance of the adsorbent to organic sulfides to some extent, prolonging the service life of the adsorbent.

[0015] Finally, the mercaptosilane modification and dopamine coating increase the adsorption sites, improve the adsorption capacity of organic sulfides, and can reduce the loss and agglomeration of metal components, improving the stability of the adsorbent.

[0016] Preferably, the total concentration of the nitrate solution A is (0.1-0.3) mol / L, and the total concentration of the nitrate solution B is (0.2-0.5) mol / L.

[0017] Preferably, the concentration of the nitric acid solution is (0.08-0.1) mol / L, and the mass fraction of the mercaptosilane solution is 10%-12%.

[0018] Preferably, the nitrate solution A is at least two of cerium nitrate, lanthanum nitrate, and samarium nitrate; and the nitrate solution B is at least two of iron nitrate, copper nitrate, and nickel nitrate.

[0019] Beneficial effects: When multiple rare earth metal nitrates and multiple transition metal nitrates are loaded together, they will produce a synergistic effect. Mainly manifested in: on the one hand, the 4f electrons of rare earth metals (such as Ce, La, Sm) are shielded by the outer layer of electrons, and have unique magnetic, optical and electrical properties. Form a conjugation effect with the 3d electrons of transition metals (such as Fe, Cu, Ni), enhance the electron cloud delocalization. The regulation of this electronic structure makes it easier for active sites to form on the surface of the adsorbent, and promotes the affinity for sulfur atoms in organic sulfides. On the other hand, when rare earth metals and transition metals are loaded together, multi-valence catalytic sites (such as Ce 3+ / Ce4+ Fe 3+ / Fe 2+ These sites catalyze the oxidative decomposition of organic sulfides through electron transfer and acid-base neutralization reactions, avoiding catalyst poisoning. These synergies collectively enhance the adsorbent's adsorption capacity, adsorption rate, and adsorption stability for organic sulfides, allowing the adsorbent to maintain high adsorption performance under different environmental conditions.

[0020] Preferably, the microporous molecular sieve is any one of 13X molecular sieve, NaY molecular sieve, ZSM-5 molecular sieve, and the mesoporous molecular sieve is any one of MCM-41 molecular sieve, SBA-15 molecular sieve, KIT-6 molecular sieve.

[0021] Preferably, the shaped body is a sphere, and the diameter of the sphere is 3-5 mm.

[0022] Preferably, the calcination temperature in step S1 is 350-450℃, and the calcination time is 2-4h.

[0023] Preferably, the first calcination temperature in step S2 is 500-600℃, and the calcination time is 2-4h; the second calcination temperature is 350-450℃, and the calcination time is 2-4h.

[0024] Preferably, in step S2, the specific steps of reduction are as follows: after the second calcination is completed, the temperature is lowered to 250-350℃, and reduction is performed under a mixed gas atmosphere for 1.5-2.5h.

[0025] The flow rate of the mixed gas is 3-5L / h, the mixed gas includes inert gas and hydrogen, and the volume ratio of the inert gas to hydrogen is (0.8-0.9):(0.1-0.2).

[0026] Beneficial effects: On the one hand, the introduction of a small amount of hydrogen can reduce some metal oxides to elemental metals or low-valence metal compounds, providing more effective active sites for the adsorption and reaction of organic sulfides, thereby improving the adsorption and removal capacity of the adsorbent for organic sulfides. On the other hand, the adsorption and reaction of hydrogen molecules on the metal surface will produce some kinetic effects, hindering the migration and aggregation of metal atoms, allowing the metal to be more uniformly dispersed on the surface and in the pores of the shaped body. At the same time, the inert gas acts as a diluent, which can reduce the local concentration of hydrogen, avoid excessive reaction of hydrogen with metal oxides, further help to control the dispersion state of the metal, increase the contact area between the metal and the organic sulfides, and improve the adsorption efficiency.

[0027] Preferably, in step S3, after adding dopamine and ending the reaction, a step of adding glutaraldehyde is further included, and after adding the glutaraldehyde, the reaction is continued for 1.5-2.5 h; the amount of the glutaraldehyde is 0.75%-1.2% of the mass of dopamine.

[0028] Preferably, the mercapto silane is any one of 3-mercaptopropyl trimethoxysilane and 3-mercaptopropyl triethoxysilane.

[0029] Preferably, in step S3, after adding the mercapto silane solution and solid-liquid separation, a step of immersion in a tannic acid solution is further included, and after immersion in the tannic acid solution, the reaction is continued for 2-4 h, followed by solid-liquid separation, washing, and standby;

[0030] The mass ratio of the total mass of the microporous molecular sieve and the mesoporous molecular sieve to the mass of the tannic acid is 1:(0.005-0.01).

[0031] Preferably, the tannic acid solution is prepared by dissolving tannic acid in water.

[0032] Beneficial effects: The tannic acid molecules can form a uniform protective film on the surface of the adsorbent. On the one hand, this protective film can prevent the metal components from directly contacting the external environment, reduce the loss and agglomeration of the metal components, and improve the stability of the adsorbent; on the other hand, tannic acid can strongly complex with metal ions to form a thick and dense film, protecting the surface of the adsorbent from corrosion. However, organic sulfides may chemically react with the adsorbent during the adsorption process to generate ammonium salts and other crystalline substances, which may block the micropores of the adsorbent, destroy its internal structure, and reduce the adsorption performance. The protective film formed by the tannic acid molecules not only has a protective effect, but also provides additional adsorption sites for the adsorbent, enhances the interaction between the adsorbent and the organic sulfides through multiple forces such as hydrogen bonding and coordination, and improves the adsorption effect.

[0033] Preferably, in step S3, after immersion in the tannic acid solution and solid-liquid separation, a step of aniline coating treatment is further included; the step of aniline coating treatment is as follows:

[0034] The aniline is dissolved in a hydrochloric acid solution to obtain an aniline hydrochloride solution, the aniline hydrochloride solution is uniformly mixed with the load-shaped body immersed in the tannic acid solution, and then ferric chloride is added, and the reaction is continued for 6-12 h, followed by solid-liquid separation, washing, and standby;

[0035] The mass ratio of the total mass of the microporous molecular sieve and the mesoporous molecular sieve to the mass of the aniline is 1:(0.005-0.01).

[0036] Preferably, the concentration of the hydrochloric acid solution is (1-1.5) mol / L, and the mass ratio of the ferric chloride to the aniline is (1-2):1.

[0037] Beneficial effects: On the one hand, under the action of ferric chloride, aniline undergoes polymerization to generate polyaniline, and polyaniline molecules can interact with organic sulfides through electrostatic interaction, hydrogen bonding and the like, thereby providing more adsorption active sites for the adsorbent and improving the adsorption capacity of the adsorbent for organic sulfides. At the same time, the polyaniline molecular chain exhibits a unique charge distribution characteristic, and organic sulfide molecules represented by thiophene can interact with it through electrostatic interaction, thereby strengthening the chemical adsorption effect. On the other hand, the rigid structure of polyaniline is embedded in the coating layer, which can play a role similar to reinforcing the skeleton, not only can greatly improve the mechanical strength of the coating layer, but also can resist the erosion of some chemicals. In addition, the polyaniline structure exhibits hydrophobicity, which enables it to selectively adsorb organic sulfide molecules and effectively reduce the competitive adsorption of other substances such as water molecules.

[0038] In a second aspect, the application provides an organic sulfide adsorbent prepared by the above preparation method.

[0039] In summary, the application has the following beneficial effects:

[0040] 1. The application compounding microporous molecular sieves and mesoporous molecular sieves to construct a shaped body with a multi-level pore structure. This unique pore system opens up an efficient channel for the diffusion and adsorption of organic sulfide molecules, greatly improving the adsorption capacity and efficiency of the adsorbent. At the same time, by using step-by-step immersion of rare earth metal nitrate solution and transition metal nitrate solution and combining with step-by-step calcination process, the loading process of active components can be precisely controlled. On the one hand, it significantly improves the loading rate of metal oxides on the molecular sieve carrier, ensuring that more active metals fully participate in subsequent reactions; on the other hand, it realizes the highly uniform dispersion of metal oxides on the surface and in the pores of the molecular sieve, avoiding the reduction of active sites due to agglomeration.

[0041] 2. The application reduces the loaded metal oxides to make some metals present in elemental or intermediate valence states. These special valence metals not only enhance the adsorption performance of organic sulfides, but also improve the resistance of the adsorbent to organic sulfides to some extent, prolonging its service life. The active groups introduced by mercaptosilane modification on the surface of the adsorbent increase the adsorption sites and improve the adsorption capacity of organic sulfides. The polydopamine layer formed by dopamine coating has abundant functional groups, further enhancing the adsorption performance of the adsorbent, while effectively reducing the loss and agglomeration of metal components, improving the stability of the adsorbent.

[0042] 3, The application preferably introduces tannic acid. The tannic acid molecules can be complexed with the loaded metal ions, change the electron cloud distribution of the metal ions, affect the charge properties and chemical activity of the adsorbent surface, and be beneficial to the adsorption of organic sulfides. At the same time, the tannic acid can form a uniform protective film on the surface of the adsorbent, prevent the metal components from directly contacting with the external environment, reduce the loss and agglomeration of the metal components, improve the stability of the adsorbent, and also act as a physical barrier to prevent the organic sulfides from damaging the internal structure of the adsorbent during the adsorption process, increase the interaction between the adsorbent and the organic sulfides, and improve the adsorption effect. DETAILED DESCRIPTION

[0043] The application will be further described in detail below in combination with examples.

[0044] The raw materials of the examples and comparative examples of the application are all ordinary commercial products except for special instructions.

[0045] The particle size of the 13X molecular sieve is 2-3 μm, the pore size is about 0.8-0.1 nm; the particle size of the NaY molecular sieve is 1-2 μm, the pore size is about 0.6-0.8 nm; the particle size of the ZSM-5 molecular sieve is 0.5-1 μm, the pore size is about 0.4-0.6 nm; the particle size of the MCM-41 molecular sieve is 0.1-0.2 μm, the pore size is about 2-10 nm; the particle size of the SBA-15 molecular sieve is 0.5-1 μm, the pore size is about 5-30 nm; the particle size of the KIT-6 molecular sieve is 0.3-0.5 μm, the pore size is about 3-8 nm.

[0046] Example 1

[0047] The example provides a preparation method of an organic sulfide adsorbent, comprising the following steps:

[0048] S1: 13X molecular sieve 60 g, MCM-41 molecular sieve 40 g and pseudoboehmite 8 g are added into a mixing container, stirred and mixed at a speed of 400 r / min for 30 min, then deionized water is slowly added while stirring until a mud-like material with certain plasticity is formed, the material is made into spheres with a diameter distribution of 3.5 mm through a ball making machine, then transferred into an oven, dried to constant weight at 100℃, then transferred into a sintering furnace, heated to 350℃, calcined for 4 h, and cooled to room temperature with the furnace to obtain a shaped body;

[0049] S2: The shaped body 100g is immersed in a nitrate solution A with a concentration of 0.1 mol / L and a volume of 200 mL, heated to 40℃, and incubated for 4 h. After filtration, the shaped body is washed once with deionized water, transferred to an oven, dried to constant weight at 100℃, and then transferred to a sintering furnace, heated to 500℃, and calcined for 4 h. The furnace is cooled to room temperature, and the shaped body is immersed in a nitrate solution B with a concentration of 0.2 mol / L and a volume of 200 mL, heated to 60℃, and incubated for 5 h. After filtration, the shaped body is washed once with deionized water, transferred to an oven, dried to constant weight at 100℃, and then transferred to a sintering furnace, heated to 350℃, calcined for 4 h, and then cooled to 250℃. High-purity nitrogen gas is introduced for 10 min, and then a mixed gas is continuously introduced for 2.5 h. The furnace is cooled to room temperature to obtain a loaded shaped body.

[0050] S3: The loaded shaped body is immersed in 300 g of a nitric acid solution with a concentration of 0.08 mol / L, stirred for 20 min, filtered, and washed with deionized water for 3 times. The shaped body is added to 300 g of a 3-mercaptopropyltrimethoxysilane solution with a pH of 4, stirred at 20℃ for 10 h, filtered, and transferred to a container. 500 g of a Tris-HCl buffer solution with a pH of 8 is added, and the container is placed on a magnetic stirrer and stirred at 150 r / min for 30 min. 1 g of dopamine is added, and the container is stirred at 20℃ for 12 h. After filtration, the shaped body is washed with deionized water for 2 times to obtain an organosulfide adsorbent.

[0051] The nitrate solution A includes cerium nitrate, lanthanum nitrate, and deionized water, the concentration of cerium nitrate is 0.06 mol / L, and the concentration of lanthanum nitrate is 0.04 mol / L. The nitrate solution B includes iron nitrate, copper nitrate, and deionized water, the concentration of iron nitrate is 0.1 mol / L, and the concentration of copper nitrate is 0.1 mol / L.

[0052] The mass fraction of the 3-mercaptopropyltrimethoxysilane solution is 10%, and the mass fraction of ethanol in the 3-mercaptopropyltrimethoxysilane solution is 50%.

[0053] The flow rate of the high-purity nitrogen gas is 3 L / h, and the flow rate of the mixed gas is 3 L / h. The mixed gas includes nitrogen gas and hydrogen gas, and the volume ratio of nitrogen gas to hydrogen gas is 0.8:0.2.

[0054] Example 2

[0055] The present embodiment provides a preparation method of an organosulfide adsorbent, including the following steps:

[0056] S1: 80 g of 13X molecular sieve, 20 g of MCM-41 molecular sieve and 15 g of pseudoboehmite were added into a mixing container, stirred and mixed at a speed of 400 r / min for 30 min, then deionized water was slowly added while stirring until a mud-like material with certain plasticity was formed, the material was passed through a ball making machine to form spheres with a diameter distribution of 5.5 mm, then transferred into an oven, dried at 100 DEG C until constant weight, then transferred into a sintering furnace, heated to 450 DEG C, calcined for 2 h, and cooled to room temperature with the furnace to obtain a shaped body;

[0057] S2: 100 g of the shaped body was immersed in a nitrate solution A with a concentration of 0.3 mol / L and a volume of 150 mL, heated to 60 DEG C, and kept for 2 h, then filtered, washed once with deionized water, transferred into an oven, dried at 100 DEG C until constant weight, then transferred into a sintering furnace, heated to 600 DEG C, calcined for 2 h, and cooled to room temperature with the furnace, then immersed in a nitrate solution B with a concentration of 0.5 mol / L and a volume of 150 mL, heated to 80 DEG C, and kept for 3 h, then filtered, washed once with deionized water, transferred into an oven, dried at 100 DEG C until constant weight, then transferred into a sintering furnace, heated to 450 DEG C, calcined for 2 h, then cooled to 350 DEG C, high-purity nitrogen was introduced for 15 min, then mixed gas was continuously introduced for 1.5 h, and the furnace was cooled to room temperature to obtain a loaded shaped body;

[0058] S3: the loaded shaped body was immersed in 300 g of a nitric acid solution with a concentration of 0.1 mol / L, stirred and mixed for 10 min, then filtered, washed with deionized water for 3 times, added into 300 g of a 3-mercaptopropyltrimethoxysilane solution with a pH of 5, stirred and reacted at 30 DEG C for 6 h, then filtered and transferred into a container, added into 500 g of a Tris-HCl buffer solution with a pH of 9, and placed the container on a magnetic stirrer, stirred and mixed at a speed of 150 r / min for 30 min, then added 3 g of dopamine, stirred and reacted at 30 DEG C for 24 h, then filtered, washed with deionized water for 2 times to obtain an organosulfide adsorbent.

[0059] In the process, the nitrate solution A comprises cerium nitrate, lanthanum nitrate and deionized water, the concentration of cerium nitrate is 0.15 mol / L, and the concentration of lanthanum nitrate is 0.15 mol / L; the nitrate solution B comprises iron nitrate, copper nitrate and deionized water, the concentration of iron nitrate is 0.2 mol / L, and the concentration of copper nitrate is 0.3 mol / L;

[0060] The mass fraction of the 3-mercaptopropyltrimethoxysilane solution is 12%, and the mass fraction of ethanol in the 3-mercaptopropyltrimethoxysilane solution is 70%;

[0061] The flow rate of the high-purity nitrogen gas is 5 L / h, and the flow rate of the mixed gas is 5 L / h, the mixed gas comprising nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen being 0.8:0.2.

[0062] Example 3

[0063] The present embodiment provides a preparation method of an organic sulfide adsorbent, comprising the following steps:

[0064] S1: 70 g of 13X molecular sieve, 30 g of MCM-41 molecular sieve, and 12 g of pseudoboehmite are added into a mixing container, stirred and mixed at a speed of 400 r / min for 30 min, then deionized water is slowly added while stirring until a mud-like material with certain plasticity is formed, the material is then made into spheres with a diameter distribution of 4.5 mm by a ball making machine, and then transferred into an oven, dried to a constant weight at 100℃, and then transferred into a sintering furnace, heated to 400℃, calcined for 3 h, and cooled to room temperature with the furnace to obtain a shaped body;

[0065] S2: 100 g of the shaped body is immersed in a nitrate solution A with a concentration of 0.2 mol / L and a volume of 180 mL, heated to 50℃, and kept for 3 h, then filtered, washed once with deionized water, transferred into an oven, dried to a constant weight at 100℃, then transferred into a sintering furnace, heated to 550℃, calcined for 3 h, and cooled to room temperature with the furnace, then immersed in a nitrate solution B with a concentration of 0.3 mol / L and a volume of 180 mL, heated to 70℃, and kept for 4 h, then filtered, washed once with deionized water, transferred into an oven, dried to a constant weight at 100℃, then transferred into a sintering furnace, heated to 400℃, calcined for 3 h, then cooled to 300℃, high-purity nitrogen gas is introduced for 15 min, and then mixed gas is continuously introduced for 2 h, and the furnace is cooled to room temperature to obtain a loaded shaped body;

[0066] S3: the loaded shaped body is immersed in 300 g of a nitric acid solution with a concentration of 0.1 mol / L, stirred and mixed for 15 min, then filtered, washed with deionized water for 3 times, added into 300 g of a 3-mercaptopropyltriethoxysilane solution with a pH of 4.5, stirred and reacted at 25℃ for 8 h, then filtered and transferred into a container, added into 500 g of a Tris-HCl buffer solution with a pH of 8.5, and placed on a magnetic stirrer, stirred and mixed at a speed of 150 r / min for 30 min, then added into 2 g of dopamine, stirred and reacted at 25℃ for 18 h, then filtered, washed with deionized water for 2 times to obtain an organic sulfide adsorbent.

[0067] The nitrate solution A comprises cerium nitrate, lanthanum nitrate and deionized water, the concentration of cerium nitrate is 0.15 mol / L, and the concentration of lanthanum nitrate is 0.05 mol / L; the nitrate solution B comprises iron nitrate, copper nitrate and deionized water, the concentration of iron nitrate is 0.15 mol / L, and the concentration of copper nitrate is 0.15 mol / L;

[0068] The mass fraction of the 3-mercaptopropyl triethoxysilane solution is 11%, and the mass fraction of ethanol in the 3-mercaptopropyl triethoxysilane solution is 60%.

[0069] The flow rate of the high-purity nitrogen gas is 5 L / h, and the flow rate of the mixed gas is 5 L / h, the mixed gas comprising nitrogen gas and hydrogen gas, and the volume ratio of the nitrogen gas to the hydrogen gas being 0.9:0.1.

[0070] Example 4

[0071] The difference between the present example and example 3 is that:

[0072] In step S3, the loaded shaped body is immersed in 300 g of a nitric acid solution with a concentration of 0.1 mol / L, stirred and mixed for 10 min, filtered, washed with deionized water for 3 times, added into 300 g of a 3-mercaptopropyl trimethoxysilane solution with a pH of 4.5, stirred and reacted at 25℃ for 8 h, filtered, transferred into a container, added into 500 g of a Tris-HCl buffer solution with a pH of 8.5, and placed on a magnetic stirrer, stirred and mixed at 150 r / min for 30 min, added into 2 g of dopamine, stirred and reacted at 25℃ for 18 h, added into 0.015 g of glutaraldehyde, kept at 25℃ for 1.5 h, filtered, washed with deionized water for 2 times, and an organosulfide adsorbent is obtained.

[0073] In step S2, the nitrate solution A comprises cerium nitrate, lanthanum nitrate, samarium nitrate and deionized water, the concentration of cerium nitrate is 0.1 mol / L, the concentration of lanthanum nitrate is 0.05 mol / L, and the concentration of samarium nitrate is 0.05 mol / L; the nitrate solution B comprises iron nitrate, copper nitrate, nickel nitrate and deionized water, the concentration of iron nitrate is 0.1 mol / L, the concentration of copper nitrate is 0.15 mol / L, and the concentration of nickel nitrate is 0.05 mol / L.

[0074] The others are the same as example 3.

[0075] Example 5

[0076] The difference between the present example and example 4 is that:

[0077] In step S1, the 13X molecular sieve is replaced by an equal mass of NaY molecular sieve, and the MCM-41 molecular sieve is replaced by an equal mass of SBA-15 molecular sieve.

[0078] In step S3, the loaded shaped body is immersed in 300g of a nitric acid solution with a concentration of 0.1mol / L, stirred and mixed for 10min, filtered, washed with deionized water for 3 times, added into 300g of a 3-mercaptopropyltrimethoxysilane solution with a pH of 4.5, stirred and reacted for 8h at 25℃, filtered, transferred into a container, added into 500g of a Tris-HCl buffer solution with a pH of 8.5, and placed on a magnetic stirrer, stirred and mixed for 30min at 150r / min, added into 2g of dopamine, stirred and reacted for 18h at 25℃, added into 0.024g of glutaraldehyde, kept at 25℃, reacted for 2.5h, filtered, washed with deionized water for 2 times, and an organosulfide adsorbent is obtained.

[0079] In step S2, the nitrate solution A includes cerium nitrate, lanthanum nitrate and deionized water, the concentration of cerium nitrate is 0.15mol / L, and the concentration of lanthanum nitrate is 0.05mol / L; the nitrate solution B includes iron nitrate, copper nitrate and deionized water, the concentration of iron nitrate is 0.15mol / L, and the concentration of copper nitrate is 0.15mol / L.

[0080] The other steps are the same as those in Example 4.

[0081] Example 6

[0082] The difference between this example and Example 3 is that:

[0083] In step S1, the amount of 13X molecular sieve is 60g, and the amount of MCM-41 molecular sieve is 40g.

[0084] In step S3, the loaded shaped body is immersed in 300g of a nitric acid solution with a concentration of 0.1mol / L, stirred and mixed for 10min, filtered, washed with deionized water for 3 times, added into 300g of a 3-mercaptopropyltrimethoxysilane solution with a pH of 4.5, stirred and reacted for 8h at 25℃, filtered, transferred into a container, added into a tannic acid solution, kept at 25℃, and continued to react for 2h, filtered, washed with deionized water for 2 times, transferred into a container, added into 500g of a Tris-HCl buffer solution with a pH of 8.5, and placed on a magnetic stirrer, stirred and mixed for 30min at 150r / min, added into 2.5g of dopamine, stirred and reacted for 18h at 25℃, added into 0.02g of glutaraldehyde, kept at 25℃, reacted for 2.5h, filtered, washed with deionized water for 2 times, and an organosulfide adsorbent is obtained.

[0085] In step S3, the loaded shaped body is immersed in 300g of a nitric acid solution with a concentration of 0.1mol / L, stirred and mixed for 10min, filtered, washed with deionized water for 3 times, added into 300g of a 3-mercaptopropyltrimethoxysilane solution with a pH of 4.5, stirred and reacted for 8h at 25℃, filtered, transferred into a container, added into a tannic acid solution, kept at 25℃, and continued to react for 2h, filtered, washed with deionized water for 2 times, transferred into a container, added into 500g of a Tris-HCl buffer solution with a pH of 8.5, and placed on a magnetic stirrer, stirred and mixed for 30min at 150r / min, added into 2.5g of dopamine, stirred and reacted for 18h at 25℃, added into 0.02g of glutaraldehyde, kept at 25℃, reacted for 2.5h, filtered, washed with deionized water for 2 times, and an organosulfide adsorbent is obtained.

[0086] The other steps are the same as those in Example 3.

[0087] Example 7

[0088] The difference between this embodiment and embodiment 6 is that:

[0089] In step S3, the loaded molded body was immersed in 300g of 0.1mol / L nitric acid solution and stirred for 10min. After filtration, it was washed three times with deionized water. Then, 300g of 3-mercaptopropyltrimethoxysilane solution with pH 4.5 was added, and the mixture was stirred at 25℃ for 8h. After filtration, the mixture was transferred to a container, tannic acid solution was added, and the temperature was kept constant at 25℃ for another 2h. After filtration, the mixture was washed twice with deionized water and transferred to a container. Then, 500g of Tris-HCl buffer with pH 8.5 was added, and the container was placed on a magnetic stirrer and stirred at 150r / min for 30min. Then, 2.5g of dopamine was added, and the mixture was stirred at 25℃ for 18h. Then, 0.02g of glutaraldehyde was added, and the mixture was stirred at 25℃ for 2.5h. After filtration, the mixture was washed twice with deionized water to obtain the organic sulfide adsorbent.

[0090] The method for preparing the tannic acid solution is as follows: 1g of tannic acid is mixed with 300g of deionized water until homogeneous.

[0091] The rest is the same as in Example 6.

[0092] Example 8

[0093] The difference between this embodiment and embodiment 7 is as follows:

[0094] In step S3, the supported molded body is immersed in 300g of 0.1mol / L nitric acid solution, stirred and mixed for 10min, filtered, washed three times with deionized water, and then added to 300g of 3-mercaptopropyltrimethoxysilane solution with pH 4.5. The mixture is stirred and reacted at 25℃ for 8h, filtered, and transferred to a container. Tannic acid solution is added, and the reaction is continued at 25℃ for 2h. The mixture is then filtered, washed twice with deionized water, transferred to a container, and aniline hydrochloride solution is added. Chloride is then slowly added. The iron solution was reacted at 25°C for 6 hours, followed by solid-liquid separation. The solution was washed twice with deionized water and transferred to a container. 500 g of Tris-HCl buffer solution with pH 8.5 was added, and the container was placed on a magnetic stirrer and stirred at 150 r / min for 30 min. Then, 2.5 g of dopamine was added, and the mixture was stirred at 25°C for 18 hours. Finally, 0.02 g of glutaraldehyde was added, and the mixture was kept at 25°C for 2.5 hours. The mixture was then filtered and washed twice with deionized water to obtain the organic sulfide adsorbent.

[0095] The preparation method of aniline hydrochloride solution is as follows: 0.5g of aniline is mixed with 300g of hydrochloric acid solution with a concentration of 1mol / L and stirred until homogeneous;

[0096] The method for preparing ferric chloride solution is as follows: mix 0.5g of ferric chloride with 50g of deionized water until homogeneous.

[0097] The rest is the same as in Example 7.

[0098] Example 9

[0099] The difference between this embodiment and embodiment 8 is as follows:

[0100] In step S1, ZSM-5 molecular sieve of equal mass is used to replace 13X molecular sieve, and KIT-6 molecular sieve of equal mass is used to replace MCM-41 molecular sieve.

[0101] In step S3, the supported molded body is immersed in 300g of 0.1mol / L nitric acid solution, stirred and mixed for 10min, filtered, washed three times with deionized water, and then added to 300g of 3-mercaptopropyltrimethoxysilane solution with pH 4.5. The mixture is stirred and reacted at 25℃ for 8h, filtered, and transferred to a container. Tannic acid solution is added, and the reaction is continued at 25℃ for 2h. The mixture is then filtered, washed twice with deionized water, transferred to a container, and aniline hydrochloride solution is added, followed by the slow addition of ferric chloride. The solution was reacted at 25°C for 12 hours, followed by solid-liquid separation. The solution was washed twice with deionized water and transferred to a container. 500 g of Tris-HCl buffer solution with pH 8.5 was added, and the container was placed on a magnetic stirrer. The mixture was stirred at 150 r / min for 30 min. Then, 2.5 g of dopamine was added, and the mixture was stirred at 25°C for 18 hours. Finally, 0.02 g of glutaraldehyde was added, and the mixture was kept at 25°C for 2.5 hours. The mixture was then filtered and washed twice with deionized water to obtain the organic sulfide adsorbent.

[0102] The preparation method of aniline hydrochloride solution is as follows: 1g of aniline is mixed with 300g of hydrochloric acid solution with a concentration of 1mol / L.

[0103] The method for preparing ferric chloride solution is as follows: mix 2g of ferric chloride with 50g of deionized water until homogeneous.

[0104] The rest is the same as in Example 8.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 1 is as follows:

[0107] S1: Add 100g of 13X molecular sieve and 8g of pseudoboehmite to a mixing container, stir and mix at 400r / min for 30min, then slowly add deionized water while stirring until a mud-like material with certain plasticity is formed. Use a pelletizing machine to make spheres with a diameter distribution of 3.5mm, then transfer them to an oven and dry them at 100℃ to constant weight. Then transfer them to a sintering furnace, heat to 350℃ and calcine for 4h, then cool to room temperature with the furnace to obtain the shaped body.

[0108] Everything else is the same as in Example 1.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is as follows:

[0111] Step S2: Take 100g of the molded body and immerse it in 900g of the mixed solution. Heat the solution to 40℃ and keep it at that temperature for 4 hours. Then, heat the solution to 60℃ and keep it at that temperature for 5 hours. Filter the solution and rinse it once with deionized water. Transfer the solution to an oven and dry it at 100℃ until it reaches constant weight. Then, transfer the solution to a sintering furnace and heat the solution to 500℃. Calcine the solution for 4 hours and then cool it down to 250℃. First, introduce high-purity nitrogen gas for 10 minutes, and then continue to introduce the mixed gas for 2.5 hours. Cool the solution to room temperature in the furnace to obtain the loaded molded body.

[0112] The preparation method of the mixture includes the following steps:

[0113] Mix 200 mL of 0.1 mol / L nitrate solution A and 200 mL of 0.2 mol / L nitrate solution B thoroughly.

[0114] Everything else is the same as in Example 1.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 1 is as follows:

[0117] S2: Immerse 100g of the molded body in 200mL of 0.1mol / L nitrate solution A, heat to 40℃, hold for 4h, filter, rinse once with deionized water, transfer to an oven, dry to constant weight at 100℃, then immerse in 200mL of 0.2mol / L nitrate solution B, heat to 60℃, hold for 5h, filter, rinse once with deionized water, transfer to an oven, dry to constant weight at 100℃, then transfer to a sintering furnace, heat to 350℃, calcine for 4h, cool to 250℃, first purge with high-purity nitrogen for 10min, then continuously purge with mixed gas for 2.5h, cool to room temperature with the furnace to obtain the loaded molded body;

[0118] Everything else is the same as in Example 1.

[0119] Comparative Example 4

[0120] This comparative example provides a method for preparing an organic sulfide adsorbent, comprising the following steps:

[0121] S1: Add 60g of 13X molecular sieve, 40g of MCM-41 molecular sieve and 8g of pseudoboehmite to a mixing container. Stir and mix at 400r / min for 30min. Then slowly add deionized water while stirring until a mud-like material with certain plasticity is formed. Use a pelletizing machine to make spheres with a diameter distribution of 3.5mm. Then transfer them to an oven and dry them at 100℃ to constant weight. Then transfer them to a sintering furnace, heat to 350℃ and calcine for 4h. Cool to room temperature with the furnace to obtain the shaped body.

[0122] S2: Take 100g of the molded body and immerse it in 200mL of nitrate solution A with a concentration of 0.1mol / L. Heat the solution to 40℃ and keep it at that temperature for 4h. After filtration, rinse it once with deionized water and transfer it to an oven. Dry it at 100℃ to constant weight. Then transfer it to a sintering furnace and heat it to 500℃ for 4h. Cool it to room temperature with the furnace and then immerse it in 200mL of nitrate solution B with a concentration of 0.2mol / L. Heat the solution to 60℃ and keep it at that temperature for 5h. After filtration, rinse it once with deionized water and transfer it to an oven. Dry it at 100℃ to constant weight and then transfer it to a sintering furnace. Heat the solution to 350℃ and calcine it for 4h. Then cool it to 250℃. First, pass high-purity nitrogen gas through the furnace for 10min, and then continue to pass mixed gas through the furnace for 2.5h. Cool it to room temperature with the furnace to obtain the organic sulfide adsorbent.

[0123] Nitrate solution A includes cerium nitrate, lanthanum nitrate, and deionized water, with a concentration of cerium nitrate of 0.06 mol / L and a concentration of lanthanum nitrate of 0.04 mol / L; nitrate solution B includes ferric nitrate, copper nitrate, and deionized water, with a concentration of ferric nitrate of 0.1 mol / L and a concentration of copper nitrate of 0.1 mol / L.

[0124] The flow rate of high-purity nitrogen is 3 L / h, and the flow rate of the mixed gas is 3 L / h. The mixed gas includes nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 0.8:0.2.

[0125] Performance testing

[0126] The organic sulfide adsorbents prepared in Examples 1-9 and Comparative Examples 1-4 were respectively packed into small fixed-bed reactors with a packing height of 6 cm. The test conditions were room temperature and pressure, and the simulated liquid hourly space velocity was 3 h⁻¹. -1Simulated liquid was continuously introduced, and the sulfur concentration at the reactor outlet was increased every 30 minutes until it reached 5% of the inlet concentration. The dynamic sulfur capacity was calculated based on the mass of the organic sulfide adsorbent, the adsorption time, and the change in sulfur concentration. The concentration changes of thiols, thioethers, and thiophenes in the liquid before and after adsorption were determined by ultraviolet fluorescence method (GB / T 11060.8-2012). The specific detection results are shown in Table 1.

[0127] Simulated liquid: Methanethiol, dimethyl sulfide, and benzothiophene are dissolved in methyl tert-butyl ether, wherein the concentration of methanethiol is 100 ppm, the concentration of dimethyl sulfide is 60 ppm, and the concentration of benzothiophene is 40 ppm.

[0128] Table 1 Performance test data of the organosulfur adsorbents prepared in Examples 1-9 and Comparative Examples 1-4

[0129]

[0130] Analysis of the data in Table 1 shows that:

[0131] Comparative analysis of Example 1 and Comparative Example 1 shows that by using a combination of microporous molecular sieve and mesoporous molecular sieve, the removal efficiency of organic sulfide adsorbent for specific sulfides (methanethiol, dimethyl sulfide and benzothiophene) can be effectively improved. This improvement may be due to the fact that the combined molecular sieve system can provide a hierarchical pore structure, thereby more effectively capturing and fixing sulfide molecules of different sizes.

[0132] Further comparative analysis of Example 1 and Comparative Examples 2-3 shows that stepwise impregnation and stepwise sintering are beneficial to the loading and distribution of metal ions on the adsorbent, reduce agglomeration, and thus improve the effective adsorption area and overall adsorption performance of the adsorbent.

[0133] Comparative analysis of Example 1 and Comparative Example 4 shows that surface treatment methods such as nitric acid treatment, mercaptosilane modification, and dopamine coating can significantly improve the dynamic sulfur capacity and adsorption performance of organic sulfide adsorbents. These treatment methods may improve adsorption efficiency and capacity by changing the chemical properties of the adsorbent surface and increasing its interaction force with sulfide molecules.

[0134] Comparative analysis of Examples 1-3 shows that by optimizing the proportions of each component, a stable and high-performance organic sulfide adsorbent can be prepared.

[0135] Comparative analysis of Examples 3-9 shows that glutaraldehyde may have optimized the adsorbent structure and enhanced its adsorption performance through cross-linking and other processes. Subsequent tannic acid modification and aniline coating further improved the adsorbent's removal efficiency for specific sulfides. This is likely because these modifications and coatings increased the number of active sites on the adsorbent surface, thereby improving its adsorption capacity and selectivity for sulfide molecules.

[0136] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing an organic sulfide adsorbent, characterized in that, Includes the following steps: S1: Mix 60-80 parts by weight of microporous molecular sieve, 20-40 parts by weight of mesoporous molecular sieve and 8-15 parts by weight of pseudoboehmite evenly, knead, shape, dry and calcinate to obtain the shaped body; S2: The molded body is immersed in nitrate solution A, heated to 40~60℃, held for 2~4 hours, separated from solid, washed, dried, and calcined for the first time. Then it is immersed in nitrate solution B, heated to 60~80℃, held for 3~5 hours, separated from solid, washed, dried, calcined for the second time, and reduced to obtain the loaded molded body. The specific steps of the reduction are as follows: after the second calcination, the temperature is lowered to 250~350℃, and the reduction is carried out for 1.5~2.5 hours in a mixed gas atmosphere. The flow rate of the mixed gas is 3~5 L / h, and the mixed gas includes inert gas and hydrogen, with a volume ratio of (0.8~0.9):(0.1~0.2). S3: The loaded molded body is immersed in nitric acid solution for 10-20 min, followed by solid-liquid separation, washing, and dispersion in a mercaptosilane solution with pH 4-5. The mixture is reacted at 20-30°C for 6-10 h, followed by solid-liquid separation, washing, and dispersion in a buffer solution with pH 8-9. Dopamine (1-3 parts by weight) is added, and the mixture is reacted at 20-30°C for 12-24 h. After the reaction, glutaraldehyde is added, and the reaction continues for 1.5-2.5 h. Solid-liquid separation, washing, and drying are then performed to obtain the organic sulfide adsorbent. The amount of glutaraldehyde used is 0.75%-1.2% of the mass of dopamine. After adding mercaptosilane solution and separating solid and liquid, the process also includes immersion in tannic acid solution. After immersion in tannic acid solution, the reaction continues for 2-4 hours, followed by solid-liquid separation, washing, and use. After immersion in tannic acid solution and solid-liquid separation, the process also includes an aniline coating treatment step. The steps of the aniline coating treatment are as follows: dissolve aniline in hydrochloric acid solution to obtain aniline hydrochloric acid solution, mix the aniline hydrochloric acid solution with the loaded molded body impregnated with tannic acid solution evenly, add ferric chloride, continue the reaction for 6~12h, separate the solid and liquid, wash, and set aside. The total mass ratio of the microporous molecular sieve and the mesoporous molecular sieve to the mass of tannic acid is 1:(0.005~0.01). The total mass ratio of the microporous molecular sieve and the mesoporous molecular sieve to the mass of aniline is 1:(0.005~0.01). The nitrate solution A comprises at least two rare earth metal nitrates; the nitrate solution B comprises at least two transition metal nitrates.

2. The method for preparing the organic sulfide adsorbent according to claim 1, characterized in that, The total concentration of nitrate solution A is (0.1~0.3) mol / L, and the total concentration of nitrate solution B is (0.2~0.5) mol / L.

3. The method for preparing the organic sulfide adsorbent according to claim 2, characterized in that, The nitrate solution A is at least two of cerium nitrate, lanthanum nitrate, and samarium nitrate; the nitrate solution B is at least two of ferric nitrate, copper nitrate, and nickel nitrate.

4. The method for preparing the organic sulfide adsorbent according to claim 1, characterized in that, The concentration of the nitric acid solution is (0.08~0.1) mol / L; the mass fraction of the mercaptosilane solution is 10%~12%.

5. The method for preparing the organic sulfide adsorbent according to claim 1, characterized in that, The microporous molecular sieve is any one of 13X molecular sieve, NaY molecular sieve, and ZSM-5 molecular sieve, and the mesoporous molecular sieve is any one of MCM-41 molecular sieve, SBA-15 molecular sieve, and KIT-6 molecular sieve.

6. An organic sulfide adsorbent prepared by the method of any one of claims 1 to 5.

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