Desulfurization adsorbent for low-carbon olefins and preparation method thereof

Abstract

The invention discloses a desulfurization adsorbent for low-carbon olefins and a preparation method of the desulfurization adsorbent, and belongs to the technical field of preparation of desulfurizers. The desulfurization adsorbent is a 13X molecular sieve with larger K < + > ion exchange aperture, so that the acting force between adsorbed molecules and cations is weak, the adsorption heat is obviously reduced, the olefin adsorption capacity is weakened, the polymerization reaction of olefin is obviously inhibited, the content of effective components can be further improved, and the adsorption capacity is improved; in the forming process of the adsorbent, a macromolecular polymer and a mesoporous high-thermal-conductivity material are added, local heat accumulation in the adsorption process is reduced, local temperature rise is relieved, meanwhile, heat is rapidly taken away, the adsorption temperature rise is small, and unexpected shutdown, olefin leakage and other dangers are avoided; in the forming process of the adsorbent, metal components are added, the adsorption sites of the adsorbent are further increased, the adsorption speed is higher, and the desulfurization efficiency is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of desulfurization agent preparation, and particularly relates to a desulfurization adsorbent for light olefins and a preparation method thereof. Background Art

[0002] In the field of petrochemicals, light olefins (such as ethylene, propylene, butene, etc.) are important basic raw materials for synthesizing polymer materials such as plastics, rubber, and fibers. However, in production processes such as petroleum cracking, coal chemical industry, or biomass conversion, light olefins are often accompanied by the generation of sulfur-containing compounds (such as hydrogen sulfide, mercaptans, sulfides, thiophenes, etc.). These sulfides not only lead to irreversible poisoning of catalysts in subsequent polymerization reactions and reduce product purity, but also corrode production equipment and increase environmental protection treatment costs. Therefore, the development of efficient, economical, and environmentally friendly desulfurization and purification technologies is a key link in improving the quality of light olefins, extending catalyst life, and achieving green chemical production.

[0003] Currently, common desulfurization technologies used in industry include catalytic hydrodesulfurization, oxidative desulfurization, and adsorption desulfurization. Adsorption has attracted considerable attention due to its mild operating conditions, low energy consumption, and simple process flow. Commonly used desulfurization adsorbents in industry include activated carbon, metal oxides, and molecular sieves.

[0004] Activated carbon has a rich pore structure, and its pore structure distribution and surface properties are key factors affecting its desulfurization performance. Modification of activated carbon can improve its adsorption capacity. Chinese patents CN112320797A, CN103495407, CN101954284, CN105056882A, CN112354518A, CN107837787A, CN103521195A, CN105903324A, CN107583636A, CN105080488B, and CN102031141B prepare activated carbon using different raw materials and processes, and then modify it to produce activated carbon desulfurizers that can be used to remove sulfides from hydrogenation products and various gases. However, even modified activated carbons have drawbacks such as low sulfur content, non-renewability, and easy desorption after adsorption.

[0005] Metal oxides (such as zinc oxide) have excellent thermodynamic properties when reacting with hydrogen sulfide, and have high desulfurization accuracy, making them a commonly used fine desulfurizer. Chinese Patent CN103769043 discloses a gas desulfurization adsorbent, its preparation method, and application. The adsorbent uses an M41S series mesoporous material as a carrier, zinc oxide as the active component, and is supplemented with a promoter, calcium oxyacid salts, and VB / VIB group metal oxides. The adsorbent can effectively remove sulfides at high temperatures. Chinese Patent CN101485954B discloses a zinc oxide desulfurizer composed of 40-90% zinc oxide, 5-50% copper oxide, and 0-20% binder. It can remove hydrogen sulfide at room temperature with high removal accuracy. Chinese Patent CN102961959B discloses a zinc oxide fine desulfurizer prepared by mixing and extruding activated zinc oxide, high-alumina powder, bentonite, calcium hydroxide, and sodium carboxymethyl cellulose. This catalyst can remove H2S from liquid propylene to as low as 0.03 ppm at room temperature. U.S. Patent No. 13395834B discloses a method for removing hydrogen sulfide from hydrocarbon streams, utilizing zinc oxide to react with hydrogen sulfide to reduce the hydrogen sulfide content in the feedstock to a certain level. However, this type of desulfurizer only adsorbs hydrogen sulfide and has no effect on organic sulfides such as carbonyl sulfide and mercaptans. Furthermore, zinc oxide desulfurizers typically achieve optimal desulfurization capacity at temperatures above 300°C, significantly reducing their sulfur capacity at ambient temperature and pressure.

[0006] Molecular sieve desulfurization is a technology that uses porous materials to selectively adsorb sulfides from gases or liquids. It is suitable for purification processes such as natural gas, refinery gas, and biogas. Common desulfurization molecular sieves include A, ZSM-5, X, and Y molecular sieves, which can selectively adsorb hydrogen sulfide and polar organic sulfides based on their polarity and pore size. Chinese patent CN114146682A discloses a regenerable adsorbent for hydrogen sulfide removal and its preparation method. The adsorbent is composed of an alkali metal salt supported on a composite carrier composed of activated alumina and ZSM-5 molecular sieves with multiple mesoporous channels. This improves the utilization of the active components, but has a low sulfur capacity.

[0007] X and Y molecular sieves, due to their three-dimensional channels and large pore size, offer greater adsorption space and more adsorption sites, resulting in significantly better sulfur capacity than other molecular sieves. However, these molecular sieves can also adsorb olefins. The exothermic adsorption and the surface reaction of olefins on the molecular sieve increase the bed temperature, triggering olefin oligomerization, leading to carbon deposition and agglomeration of the adsorbent, increased bed pressure drop, and the inability to dissipate adsorption heat, resulting in unexpected downtime and olefin leakage.

[0008] In order to solve this problem, relevant reports have mixed molecular sieves with materials with good thermal conductivity to accelerate heat transfer and alleviate local temperature rise. For example, Chinese patent CN111068611A discloses a low-carbon olefin desulfurizer and its preparation method and application. The low-carbon olefin desulfurizer includes, by weight, 5 to 20 parts of molecular sieves, 55 to 70 parts of hydrotalcite-like substances and the corresponding composite oxides obtained by calcining hydrotalcite-like substances, and 10 to 30 parts of binders. The prepared desulfurizer can be used in the production of low-carbon olefin desulfurization, but the desulfurizer obtained by this method still has the problem of slow mass transfer and diffusion; Chinese patent CN108295809A discloses a composite desulfurization adsorption The invention relates to a composite desulfurization adsorbent comprising a modified mesoporous molecular sieve, a modified microporous molecular sieve, aluminum oxide, and a nitric acid solution, mixed and shaped, and then activated. The resulting desulfurization adsorbent can effectively remove various sulfides from sulfur-containing substances. A certain amount of nitric acid is added during the preparation of the desulfurization agent, which, while increasing the sample strength, destroys the structure of the molecular sieve to a certain extent, reducing the desulfurization efficiency. Chinese patent CN117732428A discloses a renewable hydrogen sulfide removal agent, its preparation method, and application. Using silica-alumina as a carrier, an aluminum hydroxide colloidal solution is loaded onto the silica-alumina carrier, and then water vapor aging causes secondary bonding between the aluminum gel and the carrier, resulting in a hydrogen sulfide removal agent with a more concentrated pore size distribution and more abundant active adsorption sites. This patent can only adsorb hydrogen sulfide and has no removal capability for other organic sulfides. Summary of the Invention

[0009] In response to the above technical problems, the purpose of the present invention is to provide a desulfurization adsorbent for light olefins. When used to remove sulfur-containing compounds in light olefins, the desulfurization adsorbent has low adsorption heat and low reaction activity, can significantly inhibit the olefin polymerization reaction occurring during the adsorption process, and is used in the process of removing sulfur-containing compounds in light olefins. It has the characteristics of low adsorption temperature rise, high desulfurization accuracy, large desulfurization capacity and long service life.

[0010] The present invention is achieved through the following technical solutions:

[0011] A desulfurization adsorbent for light olefins is prepared from the following raw materials by mass fraction: based on the total amount of adsorbent,

[0012] The invention comprises 40-60 wt% of zeolite molecular sieve, 30-50 wt% of structural auxiliary agent, 1-8 wt% of metal auxiliary agent and 0.1-2 wt% of lubricant.

[0013] Preferably, it is prepared from the following raw materials by mass fraction: based on the total amount of adsorbent,

[0014] The invention comprises 50-60 wt% of zeolite molecular sieve, 35-45 wt% of structural auxiliary agent, 2-6 wt% of metal auxiliary agent and 0.5-1.5 wt% of lubricant.

[0015] Preferably, the zeolite molecular sieve is an X molecular sieve or a Y molecular sieve that has been exchanged with potassium ions;

[0016] The structural additive is a mixture of a macromolecular polymer and a mesoporous high thermal conductive material;

[0017] The macromolecular polymer is polyethylene or polyvinyl chloride;

[0018] The mesoporous high thermal conductive material is any one of aluminum oxide, copper oxide, zinc oxide and composite oxides thereof;

[0019] The macromolecular polymer and the mesoporous high thermal conductive material in the structural auxiliary agent are mixed in a mass ratio of 1:6 to 10.

[0020] Preferably, the zeolite molecular sieve is an X molecular sieve that has been exchanged with potassium ions;

[0021] The macromolecular polymer and the mesoporous high thermal conductive material in the structural auxiliary agent are mixed in a mass ratio of 1:7 to 9.

[0022] Preferably, the metal additive is composed of a mixture of two metal sodium salts;

[0023] The first metal sodium salt is any one of sodium acetate, sodium carbonate or sodium citrate;

[0024] The second metal sodium salt is a sodium alkoxide;

[0025] The lubricant is graphite or sesbania powder.

[0026] Preferably, the first metal sodium salt is sodium acetate;

[0027] The sodium alcoholate is sodium ethanolate.

[0028] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0029] S1. Preparation of zeolite molecular sieve:

[0030] The molecular sieve raw powder is subjected to ion exchange with an aqueous solution containing potassium ions, filtered, washed, dried, and calcined to obtain a zeolite molecular sieve;

[0031] S2. Preparation of metal additives:

[0032] Add the first metal sodium salt into water and dissolve it, measure the pH of the solution, slowly add the second metal sodium salt and adjust the pH of the solution to >9 to obtain a metal additive aqueous solution;

[0033] S3. Mix and grind the zeolite molecular sieve, structural additive and lubricant, and then put them into a disc ball rolling machine. Slowly add the aqueous solution of the metal additive while rolling. After agglomeration and ball forming, dry, calcine and activate to obtain the product.

[0034] Preferably, in S1, the aqueous solution containing potassium ions is any one of potassium chloride solution, potassium nitrate solution or potassium acetate solution;

[0035] The solid-liquid ratio of the ion exchange is 1:3 to 12;

[0036] The ion exchange temperature is 60-95°C and the duration is 2-10 hours;

[0037] The drying temperature is 80-110°C and the drying time is 10-14 hours;

[0038] The calcination temperature is 500-600°C and the calcination time is 1-3 hours;

[0039] In said S2, the pH of the solution is adjusted to 11-13;

[0040] The mass ratio of the first metal salt to the second metal salt is 10 to 30:1.

[0041] Preferably, the aqueous solution containing potassium ions is a potassium chloride solution, and the molar concentration of the potassium chloride solution is 0.2 to 0.8 mol / L;

[0042] The solid-liquid ratio of the ion exchange is 1:5-10.

[0043] Preferably, in S3, the grinding is performed to a particle size of less than 100 μm.

[0044] Compared with the prior art, the present invention has at least the following technical effects:

[0045] (1) The desulfurization adsorbent provided by the present invention has low adsorption heat and low reaction activity when used to remove sulfur-containing compounds in light olefins, can significantly inhibit the olefin polymerization reaction occurring during the adsorption process, and is used in the process of removing sulfur-containing compounds in light olefins. It has the characteristics of low adsorption temperature rise, high desulfurization accuracy, large desulfurization capacity and long service life.

[0046] (2) Select K + The 13X molecular sieve has a larger ion exchange pore size, and the adsorbed molecules are not restricted in the pores, and the interaction force with the cations is weak. In addition, the molecular sieve has a low charge density, which weakens the electric field strength, significantly reduces the adsorption heat, and weakens the ability of the molecular sieve to adsorb olefins, which significantly inhibits the olefin polymerization reaction that occurs during the adsorption process. At the same time, it can further increase the content of effective components and improve the adsorption capacity.

[0047] (3) During the adsorbent molding process, macromolecular polymers and mesoporous high thermal conductivity materials are added. The macromolecular polymers can be used as templates to introduce mesopores, and the mesoporous high thermal conductivity materials can accelerate heat transfer, so that heat is quickly taken away. At the same time, the adsorbed molecules can be adsorbed in multiple layers on the mesopores introduced by the macromolecular polymers and the surface of the mesoporous high thermal conductivity materials to reduce the average adsorption heat, reduce local heat accumulation during the adsorption process, alleviate local temperature rise, and avoid unexpected shutdowns, olefin leakage and other dangers.

[0048] (4) During the adsorbent molding process, a metal component is added. This metal component is different from the metal cations in the molecular sieve exchange site. The metal component is added in the form of an organic metal salt, which increases the adsorption sites, makes the adsorption speed faster, and increases the adsorption efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the adsorption-desorption isotherm results of the sulfide adsorbent prepared in Example 1, Comparative Example 1 and Comparative Example 5. DETAILED DESCRIPTION

[0050] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Specific conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0051] Example 1:

[0052] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0053] 500 g of 13X molecular sieve powder (Shanghai Jiuzhou Chemical Co., Ltd.) was weighed and added to 5 L of 1 mol / L KCl solution. After ion exchange at 80°C for 3 h, the product was filtered, washed, dried at 105°C for 12 h, and calcined at 550°C for 2 h to obtain potassium-exchanged high-13X molecular sieve.

[0054] Weigh 500 g of the potassium-exchanged 13X molecular sieve above and add it to 5 L of a 1.5 mol / L KCl solution. After ion exchange at 80°C for 3 h, filter, wash, dry at 105°C for 12 h, and calcine at 550°C for 2 h to obtain KX molecular sieve raw powder with a potassium exchange degree greater than 40%;

[0055] Weigh 54 g of sodium acetate and dissolve it in 320 g of deionized water. Slowly add 3.4 g of sodium ethoxide. The pH of the solution is measured to be 12 to obtain a metal additive aqueous solution.

[0056] 400 g of KX molecular sieve powder, 258 g of alumina, 32 g of polyethylene, and 14.5 g of sesbania powder were weighed and mixed evenly, then placed in a ball mill and ground to a particle size of less than 100 μm. The mixture was then placed in a disc ball mill and 370 g of a metal additive aqueous solution was slowly sprayed into the mixture while rolling. The mixture was rolled into balls of 2-4 mm and dried at 100 ° C for 12 h. The mixture was then calcined at 500 ° C for 4 h to obtain the sulfide adsorbent DS-A1 of Example 1.

[0057] Example 2:

[0058] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0059] According to the steps of Example 1, KX molecular sieve raw powder with a potassium exchange degree greater than 40% was obtained;

[0060] Weigh 47 g of sodium citrate and dissolve it in 320 g of deionized water. Slowly add 3.4 g of sodium ethoxide. The pH of the solution is measured to be 12 to obtain a metal additive aqueous solution.

[0061] 422 g of KX molecular sieve powder, 235 g of zinc oxide, 34 g of polyvinyl chloride, and 14.5 g of sesbania powder were weighed and mixed evenly, then placed in a ball mill and ground to a particle size of less than 100 μm. The mixture was then loaded into a disc ball rolling machine, and 390 g of a metal additive aqueous solution was slowly sprayed into the mixture while rolling. The mixture was rolled into balls with a diameter of 2-4 mm. After drying at 105 ° C for 10 h, the mixture was calcined at 550 ° C for 2 h to obtain the sulfide adsorbent DS-A2 of Example 2.

[0062] Comparative Example 1:

[0063] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0064] Weigh 560g of 13X molecular sieve powder (Shanghai Jiuzhou Chemical Co., Ltd.), 240g of attapulgite and 16g of sesbania powder, mix them evenly and place them in a ball mill. Grind them to a particle size of less than 100um, load them into a disc ball rolling machine, slowly spray 360g of deionized water while rolling, and roll them into balls of 2-4mm. After drying at 100°C for 12h, they are calcined at 500°C for 4h to obtain the sulfide adsorbent DS-B1 of Comparative Example 1.

[0065] Comparative Example 2:

[0066] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0067] Weigh 47 g of sodium citrate and dissolve it in 320 g of deionized water. Slowly add 3.4 g of sodium ethoxide. The pH of the solution is measured to be 12 to obtain a metal additive aqueous solution.

[0068] Weigh 560g of 13X molecular sieve raw powder (Shanghai Jiuzhou Chemical Co., Ltd.), 240g of attapulgite and 16g of sesbania powder, mix evenly and place in a ball mill, grind to a particle size of less than 100um, load into a disc ball rolling machine, slowly spray 360g of metal additive aqueous solution while rolling, roll into balls to 2-4mm, dry at 105°C for 10h, and calcined at 550°C for 5h to obtain the sulfide adsorbent DS-B2 of Comparative Example 2.

[0069] Comparative Example 3:

[0070] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0071] Weigh 400g of 13X molecular sieve powder (Shanghai Jiuzhou Chemical Co., Ltd.), 258g of alumina, 32g of polyethylene and 14.5g of sesbania powder, mix them evenly and place them in a ball mill. Grind them to a particle size of less than 100um, load them into a disc ball rolling machine, slowly spray 320g of deionized water while rolling, and roll them into balls of 2-4mm. After drying at 100°C for 12h, they are calcined at 500°C for 4h to obtain the sulfide adsorbent DS-B3 of Comparative Example 3.

[0072] Comparative Example 4:

[0073] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0074] Weigh 700 g of 13X molecular sieve raw powder (Shanghai Jiuzhou Chemical Co., Ltd.) and add it to 7 L of 1 mol / L KCl solution. After ion exchange at 80 ° C for 3 h, filter, wash, dry at 105 ° C for 12 h, and calcine at 550 ° C for 2 h to obtain potassium-exchanged high 13X molecular sieve; weigh the above 700 g of potassium-exchanged 13X molecular sieve and add it to 7 L of 1.5 mol / L KCl solution. After ion exchange at 80 ° C for 3 h, filter, wash, dry at 105 ° C for 12 h, and calcine at 550 ° C for 2 h to obtain KX molecular sieve raw powder with a potassium exchange degree greater than 40%;

[0075] Weigh 560g of KX molecular sieve raw powder, 240g of attapulgite and 16g of sesbania powder, mix them evenly and place them in a ball mill. Grind them to a particle size of less than 100um, load them into a disc ball rolling machine, slowly spray 350g of deionized water while rolling, and roll them into balls of 2-4mm. After drying at 110°C for 10h, they are calcined at 500°C for 4h to obtain the sulfide adsorbent DS-B4 of Comparative Example 4.

[0076] Comparative Example 5:

[0077] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0078] Weigh 47 g of sodium citrate and dissolve it in 320 g of deionized water. Slowly add 3.4 g of sodium ethoxide. The pH of the solution is measured to be 12 to obtain a metal additive aqueous solution.

[0079] Weigh 140g of 13X molecular sieve powder (Shanghai Jiuzhou Chemical Co., Ltd.), 530g of alumina powder and 14.5g of sesbania powder, mix them evenly and place them in a ball mill. Grind them to a particle size of less than 100um, load them into a disc ball rolling machine, slowly spray 320g of metal additive aqueous solution while rolling, and roll them into balls of 2-4mm. After drying at 110°C for 10h, they are calcined at 500°C for 4h to obtain the sulfide adsorbent DS-B5 of Comparative Example 5.

[0080] Example 3:

[0081] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0082] According to the steps of Example 1, KX molecular sieve raw powder with a potassium exchange degree greater than 40% was obtained;

[0083] Weigh 54 g of sodium acetate and dissolve it in 320 g of deionized water. Slowly add 2.2 g of sodium methoxide. The pH of the solution is measured to be 11.5 to obtain a metal additive aqueous solution.

[0084] 400 g of KX molecular sieve powder, 253 g of zinc-aluminum composite oxide, 28 g of polyethylene, and 14.5 g of sesbania powder were weighed, mixed, and placed in a ball mill. Grind to a particle size of less than 100 μm, load into a disc ball mill, slowly spray 360 g of a metal additive aqueous solution while rolling, and roll into balls of 2-4 mm. After drying at 110° C. for 12 h, the mixture was calcined at 550° C. for 2 h to obtain the sulfide adsorbent DS-A3 of Example 3.

[0085] Example 4:

[0086] A method for preparing a desulfurization adsorbent for light olefins comprises the following steps:

[0087] According to the steps of Example 1, KX molecular sieve raw powder with a potassium exchange degree greater than 40% was obtained;

[0088] Weigh 47 g of sodium citrate and dissolve it in 320 g of deionized water. Slowly add 2.2 g of sodium methoxide. The pH of the solution is measured to be 11.5 to obtain a metal additive aqueous solution.

[0089] 422 g of KX molecular sieve powder, 246 g of copper-zinc-aluminum composite oxide, 40 g of polyvinyl chloride, and 14.5 g of sesbania powder were weighed and mixed evenly, then placed in a ball mill and ground to a particle size of less than 100 μm. The mixture was then loaded into a disc ball mill and slowly sprayed with 370 g of a metal additive aqueous solution while rolling. The mixture was rolled into balls with a diameter of 2-4 mm. The mixture was dried at 110° C. for 12 h and then calcined at 550° C. for 2 h to obtain the sulfide adsorbent DS-A4 of Example 4.

[0090] Experimental example:

[0091] In order to illustrate the effect of the sulfide adsorbent provided by this application, the following experiments were conducted:

[0092] 1. Analytical characterization:

[0093] Physical adsorption analysis was performed on the sulfide adsorbents prepared in Example 1, Comparative Example 1 and Comparative Example 5, and the results were as follows:

[0094] Figure 1 The adsorption-desorption isotherm results of the sulfide adsorbents prepared in Example 1, Comparative Example 1 and Comparative Example 5.

[0095] From the above Figure 1 The results show that the process in Example 1 can obtain a sulfide adsorbent with a high content of active components and a certain amount of mesopores. The high content of active components makes the adsorbent have a higher sulfur capacity, and a certain amount of mesopore distribution is conducive to rapid mass transfer.

[0096] 2. Performance Testing

[0097] The sulfide adsorbents of Examples 1-4 and Comparative Examples 1-5 were tested for adsorption desulfurization performance on a micro-evaluation device.

[0098] The test conditions are 38°C, 0.2MPa, and air velocity of 7 to 9h -1 The desulfurizer loading amount is 20g. It is pretreated with inert gas at 350℃ for 2h. After cooling to room temperature, a propylene-propane mixed solution is introduced. The sulfide impurities are hydrogen sulfide, ethyl mercaptan and ethyl sulfide, and the total sulfur content is 15mg / m 3 .

[0099] The inlet and outlet propylene contents were detected by gas chromatography, and the outlet sulfide content was detected by thermal desorption concentration & gas chromatography FPD detector. When the outlet total sulfur content was greater than 0.1 ppm, the adsorption reaction process was stopped. This was considered as one test operation cycle. The test results are listed in Table 1 below.

[0100] Table 1 Comparison of desulfurization adsorbents of Examples 1-4 and Comparative Examples 1-5

[0101]

[0102] As can be seen from Table 1, compared with Comparative Examples 1-3, the sulfide adsorbents prepared in Examples 1-4 have significantly lower amounts of propylene adsorbed, and the adsorption temperature rise is lower in actual use; compared with Comparative Example 4, the sulfide adsorbents prepared in Examples 1-4 also have lower amounts of propylene adsorbed, and higher sulfur capacity, indicating that the added structural additives also inhibit the adsorption of olefins, which is conducive to rapid mass transfer; compared with Comparative Example 5, the sulfide adsorbents prepared in Examples 1-4 have significantly increased sulfur adsorption capacity, while the amount of propylene adsorbed is not much increased, indicating that the sulfide adsorbents prepared in Examples have the characteristics of higher sulfur capacity and lower adsorption temperature rise.

[0103] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A desulfurization adsorbent for light olefins, characterized in that: It is prepared from the following raw materials by mass fraction: based on the total amount of adsorbent, The invention comprises 40-60 wt% of zeolite molecular sieve, 30-50 wt% of structural auxiliary agent, 1-8 wt% of metal auxiliary agent and 0.1-2 wt% of lubricant.

2. The desulfurization adsorbent for light olefins according to claim 1, characterized in that: It is prepared from the following raw materials by mass fraction: based on the total amount of adsorbent, The invention comprises 50-60 wt% of zeolite molecular sieve, 35-45 wt% of structural auxiliary agent, 2-6 wt% of metal auxiliary agent and 0.5-1.5 wt% of lubricant.

3. A desulfurization adsorbent for light olefins according to claim 1 or 2, characterized in that: The zeolite molecular sieve is an X molecular sieve or a Y molecular sieve that has been exchanged with potassium ions; The structural additive is a mixture of a macromolecular polymer and a mesoporous high thermal conductive material; The macromolecular polymer is polyethylene or polyvinyl chloride; The mesoporous high thermal conductive material is any one of aluminum oxide, copper oxide, zinc oxide and composite oxides thereof; The macromolecular polymer and the mesoporous high thermal conductive material in the structural auxiliary agent are mixed in a mass ratio of 1:6 to 10.

4. The desulfurization adsorbent for light olefins according to claim 3, characterized in that: The zeolite molecular sieve is an X molecular sieve that has been exchanged with potassium ions; The macromolecular polymer and the mesoporous high thermal conductive material in the structural auxiliary agent are mixed in a mass ratio of 1:7 to 9.

5. The desulfurization adsorbent for light olefins according to claim 1 or 2, characterized in that: The metal additive is composed of a mixture of two metal sodium salts; The first metal sodium salt is any one of sodium acetate, sodium carbonate or sodium citrate; The second metal sodium salt is a sodium alkoxide; The lubricant is graphite or sesbania powder.

6. The desulfurization adsorbent for light olefins according to claim 5, characterized in that: The first metal sodium salt is sodium acetate; The sodium alcoholate is sodium ethanolate.

7. A method for preparing a desulfurization adsorbent for light olefins according to any one of claims 1 to 6, characterized in that: The steps include: S1. Preparation of zeolite molecular sieve: The molecular sieve raw powder is subjected to ion exchange with an aqueous solution containing potassium ions, filtered, washed, dried, and calcined to obtain a zeolite molecular sieve; S2. Preparation of metal additives: Add the first metal sodium salt into water and dissolve it, measure the pH of the solution, slowly add the second metal sodium salt and adjust the pH of the solution to >9 to obtain a metal additive aqueous solution; S3. Mix and grind the zeolite molecular sieve, structural additive and lubricant, and then put them into a disc ball rolling machine. Slowly add the aqueous solution of the metal additive while rolling. After agglomeration and ball forming, dry, calcine and activate to obtain the product.

8. The method for preparing a desulfurization adsorbent for light olefins according to claim 7, characterized in that: In S1, the aqueous solution containing potassium ions is any one of potassium chloride solution, potassium nitrate solution or potassium acetate solution; The solid-liquid ratio of the ion exchange is 1:3 to 12; The ion exchange temperature is 60-95°C and the duration is 2-10 hours; The drying temperature is 80-110°C and the drying time is 10-14 hours; The calcination temperature is 500-600°C and the calcination time is 1-3 hours; In said S2, the pH of the solution is adjusted to 11-13; The mass ratio of the first metal salt to the second metal salt is 10 to 30:

1.

9. The method for preparing a desulfurization adsorbent for light olefins according to claim 8, characterized in that: The aqueous solution containing potassium ions is a potassium chloride solution, and the molar concentration of the potassium chloride solution is 0.2 to 0.8 mol / L; The solid-liquid ratio of the ion exchange is 1:5-10.

10. The method for preparing a desulfurization adsorbent for light olefins according to claim 7, characterized in that: In the step S3, the powder is ground to a particle size of less than 100 μm.

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