Arsenic removal agent and preparation method thereof

Abstract

The present application belongs to the technical field of purification materials for petroleum chemical industry, and discloses a kind of dearsenical agent and its preparation method, the dearsenical agent is composed of carrier and active component, the active component includes lead oxide, manganese oxide and silver oxide, the carrier is high specific surface area alumina ball, the preparation method includes carrier preparation, step-by-step impregnation and calcination, the present application adopts ternary active component and high specific surface area carrier, significantly improves the arsenic capacity of dearsenical agent, dearsenical precision and service life, especially suitable for dearsenical of acetylenic hydrocarbon raw material, and has good industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical purification materials technology, specifically relating to an arsenic removal agent and its preparation method. Background Technology

[0002] Arsenic compounds are deadly catalyst poisons. Many industrially used catalysts are highly sensitive to arsenic compounds; even a few hundred ppb or a few ppb of arsenic compounds can poison and deactivate the catalyst, and the higher the concentration of arsenic compounds, the faster the deactivation. In petrochemical and olefin polymerization processes, raw materials (such as cracked gas, propylene, ethylene, and naphtha) often contain trace amounts of arsenic compounds. These arsenic compounds are potent poisons for downstream precious metal hydrogenation and polymerization catalysts, causing rapid and permanent deactivation and resulting in huge economic losses. Therefore, arsenic compounds must be thoroughly removed by dearsenic removal agents before the raw materials enter the core reaction unit.

[0003] Currently, the widely used arsenic removal agents in industry mainly include copper-based, nickel-based, and other arsenic removal agents. Copper-based arsenic removal agents are only suitable for removing arsine from olefins such as propylene that do not contain alkynes. They cannot be used to treat raw materials containing alkynes (such as acetylene and methylacetylene) because the carbon-carbon triple bonds in alkyne molecules are chemically reactive and readily react with copper ions or zero-valent copper to form copper acetylide. Copper acetylide is an explosive substance that is extremely unstable to impact, friction, and heat, and dry copper acetylide can spontaneously combust in air, posing a significant safety hazard. Nickel-based arsenic removal agents are mainly used for hydroremoval of arsenic, requiring a certain proportion of hydrogen in the raw material. They are not suitable for the refining of ethylene, propylene, and other raw materials for arsenic removal.

[0004] Existing patent document CN113828347B discloses an arsenic removal agent and its preparation method, comprising a carrier and an active component, wherein the active component accounts for 20-40% of the total mass of the arsenic removal agent; wherein the active component is lead peroxide (…). ) and silver peroxide ( The carrier is a calcined product of a mixture of macroporous alumina, molecular sieve, and magnesium-containing compounds. The method uses an alkaline solution for sample shaping and adds an oxidant to increase the valence state of the active metal component. This arsenic removal agent achieves an arsenic removal accuracy of 0.1 ppb and an arsenic capacity of 21.37%.

[0005] However, this technology has the following shortcomings: First, lead peroxide and silver peroxide in the active components are high-valence oxides, which are complex to prepare and require strong oxidant treatment, increasing production costs and safety risks; second, high-valence oxides have relatively poor stability and are prone to decomposition during storage and use, affecting the long-term performance and storage stability of the arsenic removal agent; third, although the arsenic capacity of this arsenic removal agent has been improved, there is still room for further improvement in the treatment of raw materials with high arsenic content, and the service life of industrial equipment needs to be extended. Therefore, developing an arsenic removal agent that combines high safety, high arsenic capacity, long life, high arsenic removal accuracy, and a simple preparation process has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an arsenic removal agent and its preparation method. This arsenic removal agent uses lead oxide, manganese oxide, and silver oxide as ternary active components. Compared with existing technologies, it has advantages such as simple preparation process, good stability of active components, high arsenic capacity, high arsenic removal precision, long service life, and wide applicability. It is particularly suitable for the precise removal of arsine from raw materials containing alkynes.

[0007] To achieve the above objectives, the first aspect of the present invention provides an arsenic removal agent, comprising a carrier and an active component, wherein the active component accounts for 35-60% of the total mass of the arsenic removal agent; wherein the active component includes lead oxide, manganese oxide, and silver oxide, wherein the mass percentage of lead oxide is 15-30%, the mass percentage of manganese oxide is 10-30%, and the mass percentage of silver oxide is 0.1-5%; the carrier is alumina spheres with a high specific surface area, and the specific surface area of ​​the carrier is 500-1000 m². 2 / g, pore volume is 0.6-1.0mL / g.

[0008] Preferably, the molar ratio of lead, manganese and silver in the active component is (10-15):(8-12):(0.05-2.5).

[0009] Preferably, the lead oxide has a mass percentage content of 20-25%, the manganese oxide has a mass percentage content of 20-25%, and the silver oxide has a mass percentage content of 1-5%.

[0010] Preferably, the specific surface area of ​​the carrier is 700-900 m². 2 / g, pore volume is 0.7-0.9mL / g.

[0011] A second aspect of the present invention provides a method for preparing the above-mentioned arsenic removal agent, comprising the following steps:

[0012] Step 1, Carrier Preparation: Hydrochloric acid solution was added to macroporous pseudoboehmite powder, followed by acidification with nitric acid, and then neutralization with ammonia and guar gum powder to form an alumina sol. Alumina spheres were prepared using a drop ball forming method. After aging, pressure filtration, washing, and drying, the spheres were calcined at 700-800℃ for 2-4 hours to obtain alumina sphere carriers with high specific surface area.

[0013] Step 2, First Impregnation: Prepare a mixed salt solution of lead acetate and silver nitrate. Add the carrier obtained in Step 1 to the drum, and spray the mixed salt solution evenly onto the carrier for equal-volume impregnation. After drying, obtain the semi-finished arsenic removal agent.

[0014] Step 3, Second Impregnation: Prepare a manganese nitrate solution and spray it evenly onto the arsenic removal agent semi-finished product obtained in Step 2;

[0015] Step 4, calcination: The product obtained in step 3 is dried at 100-140℃ for 8-12 hours, and then calcined at 450-550℃ for 4-6 hours to obtain the arsenic removal agent.

[0016] Preferably, in step 1, the mass concentration of the hydrochloric acid solution is 5-15%, the mass concentration of the nitric acid is 20-40%, and the mass concentration of the ammonia solution is 5-10%.

[0017] Preferably, in step 1, the aging time is 12-24 hours and the aging temperature is 40-60°C; the drying temperature is 100-140°C and the drying time is 6-10 hours.

[0018] Preferably, in step 2, the method for preparing the mixed salt solution is as follows: lead acetate and silver nitrate are dissolved in water and heated to 60-90°C to ensure complete dissolution; the amount of lead acetate and silver nitrate in the mixed salt solution is calculated and determined based on the target lead oxide and silver oxide content.

[0019] Preferably, in step 3, the manganese nitrate solution is prepared by dissolving manganese nitrate in water and heating it to 60-90°C until it is completely dissolved; the amount of manganese nitrate used is determined based on the target manganese oxide content.

[0020] The beneficial effects of this invention are as follows:

[0021] First, this invention uses lead oxide, manganese oxide, and silver oxide as ternary active components. Compared with lead peroxide and silver peroxide in the prior art, lead oxide and manganese oxide are low-valence oxides with more stable chemical properties. They do not require treatment with strong oxidants, resulting in a simpler preparation process, lower production costs, and higher safety. Furthermore, they are less prone to decomposition during storage and use, significantly improving stability. The introduction of manganese oxide enhances the arsenic removal effect and provides some desulfurization performance, expanding the application range of the arsenic removal agent. Silver oxide, as a noble metal active component, further improves the arsenic removal precision. A synergistic effect occurs among the ternary active components: lead oxide and manganese oxide are responsible for removing most of the arsine, while silver oxide removes the arsine concentration to an extremely low level, significantly improving the arsenic removal precision and arsenic capacity.

[0022] Secondly, this invention uses high specific surface area alumina spheres as a carrier, with a specific surface area reaching 500-1000 m². 2 / g, with a pore volume of 0.6-1.0mL / g, compared to existing macroporous alumina supports (specific surface area ≥440m²), 2 The carrier of this invention has a larger specific surface area (pore volume ≥ 1.0 mL / g), providing more active sites, increasing the dispersion and utilization rate of active components, thereby significantly improving the arsenic capacity and arsenic removal accuracy of the arsenic removal agent. The macroporous structure facilitates the rapid diffusion and sufficient contact of arsine, improving arsenic removal efficiency.

[0023] Third, the total content of active components in this invention is 35-60%, higher than the 20-40% in the prior art. This means that the arsenic removal agent per unit mass contains more active components, can remove more arsine, significantly improves arsenic capacity, and extends industrial service life. Experimental data show that the arsenic removal agent of this invention can achieve an arsenic capacity of 18.91-26.88% and an arsenic removal accuracy of 0.1-0.5 ppb, which is significantly better than existing arsenic removal agent products.

[0024] Fourth, the preparation method of this invention employs a stepwise impregnation process, first impregnating with a mixed salt solution of lead acetate and silver nitrate, and then impregnating with a manganese nitrate solution. This stepwise impregnation method facilitates the uniform and gradient distribution of active components on the carrier surface, avoids mutual interference between different active components, and ensures that each active component fully exerts its function. Simultaneously, by optimizing the calcination conditions, a good bond is formed between the active components and the carrier, improving the mechanical strength and stability of the arsenic removal agent.

[0025] Fifth, the arsenic removal agent of this invention has a wide range of applications and can be used for the purification and removal of hydrogen arsine from raw materials such as naphtha, gaseous or liquid hydrocarbons. It is particularly suitable for the precise removal of hydrogen arsine from raw materials containing alkynes, and its safety is greatly improved. This arsenic removal agent fixes highly toxic, gaseous hydrogen arsine into solid arsenic compounds through an oxidation-reduction reaction, thereby removing it from the raw material gas. The arsenic removal principle is as follows:

[0026]

[0027]

[0028]

[0029] In summary, the arsenic removal agent and its preparation method provided by this invention, by optimizing the type, content and ratio of active components, selecting high specific surface area alumina spheres as carriers, and adopting a stepwise impregnation process, significantly improve the arsenic capacity, arsenic removal accuracy, service life and stability of the arsenic removal agent, while reducing preparation costs and safety risks, and have good prospects for industrial application. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below through specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the raw materials and instruments used in the embodiments are all conventional products that can be obtained through commercial channels.

[0032] Example 1

[0033] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0034] Step 1, Carrier Preparation: A 10% (w / w) hydrochloric acid solution was added to macroporous pseudoboehmite powder, followed by acidification with 30% (w / w) nitric acid, and then neutralization with 8% (w / w) ammonia and guar gum powder to form an alumina sol. Highly spherical alumina spheres were prepared using a drop-ball forming method. After aging at 50℃ for 18 hours, pressure filtration, washing, and drying at 120℃ for 8 hours, the spheres were finally calcined at 750℃ for 3 hours to obtain a high specific surface area alumina sphere carrier with a specific surface area of ​​800 m². 2 / g, pore volume is 0.8mL / g.

[0035] Step 2, First Impregnation: Based on a lead oxide content of 15% and a silver oxide content of 0.1% in the arsenic removal agent, weigh out 25.49g of lead acetate (…). ) and 0.15g silver nitrate ( Dissolve the alumina ball carrier prepared in step 1 in water and heat it to 80°C to completely dissolve it, thus preparing a mixed salt solution. Take 70g of the alumina ball carrier prepared in step 1 and place it in a rotating drum. Use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry it at 120°C for 8 hours to obtain the arsenic removal agent semi-finished product.

[0036] Step 3, Second Impregnation: Based on a manganese oxide content of 15% in the arsenic removal agent, weigh out 43.31g of manganese nitrate ( Dissolve the manganese nitrate in water and heat to 80°C until completely dissolved to prepare a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in step 2.

[0037] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0038] Example 2

[0039] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0040] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0041] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 20% and the silver oxide content is 0.5%, weigh out 33.99g of lead acetate and 0.75g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0042] Step 3, Second Impregnation: Assuming the manganese oxide content in the arsenic removal agent is 20%, weigh out 57.75g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until it is completely dissolved, preparing a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0043] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0044] Example 3

[0045] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0046] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0047] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 25% and the silver oxide content is 1%, weigh out 42.49g of lead acetate and 1.5g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0048] Step 3, Second Impregnation: Assuming the manganese oxide content in the arsenic removal agent is 20%, weigh out 57.75g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until it is completely dissolved, preparing a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0049] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0050] Example 4

[0051] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0052] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0053] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 20% and the silver oxide content is 2%, weigh out 33.99g of lead acetate and 3g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0054] Step 3, Second Impregnation: Based on a manganese oxide content of 25% in the arsenic removal agent, weigh out 72.19g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until completely dissolved to prepare a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0055] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0056] Example 5

[0057] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0058] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0059] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 25% and the silver oxide content is 3%, weigh out 42.49g of lead acetate and 4.5g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0060] Step 3, Second Impregnation: Based on a manganese oxide content of 25% in the arsenic removal agent, weigh out 72.19g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until completely dissolved to prepare a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0061] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0062] Example 6

[0063] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0064] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0065] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 20% and the silver oxide content is 5%, weigh out 33.99g of lead acetate and 7.5g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0066] Step 3, Second Impregnation: Assuming the manganese oxide content in the arsenic removal agent is 20%, weigh out 57.75g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until it is completely dissolved, preparing a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0067] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0068] Example 7

[0069] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0070] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0071] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 25% and the silver oxide content is 5%, weigh out 42.49g of lead acetate and 7.5g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0072] Step 3, Second Impregnation: Assuming the manganese oxide content in the arsenic removal agent is 20%, weigh out 57.75g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until it is completely dissolved, preparing a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0073] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0074] Example 8

[0075] This embodiment provides an arsenic removal agent, the preparation method of which includes the following steps:

[0076] Step 1, Carrier preparation: The method is the same as in Example 1, to obtain alumina sphere carriers with high specific surface area.

[0077] Step 2, First Impregnation: Assuming the lead oxide content in the arsenic removal agent is 20% and the silver oxide content is 5%, weigh out 33.99g of lead acetate and 7.5g of silver nitrate, dissolve them in water, and heat to 80℃ to completely dissolve them, preparing a mixed salt solution. Place 70g of the alumina ball carrier prepared in Step 1 into a rotating drum, and use a spray gun to evenly spray the mixed salt solution onto the carrier for equal-volume impregnation. Dry at 120℃ for 8 hours to obtain the arsenic removal agent semi-finished product.

[0078] Step 3, Second Impregnation: Based on a manganese oxide content of 25% in the arsenic removal agent, weigh out 72.19g of manganese nitrate and dissolve it in water. Heat the solution to 80℃ until completely dissolved to prepare a manganese nitrate solution. Spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2.

[0079] Step 4, calcination: The product obtained in step 3 is dried at 120°C for 10 hours, and then calcined at 500°C for 5 hours to obtain the arsenic removal agent.

[0080] Comparative Example 1

[0081] This comparative example prepared the arsenic removal agent according to the method in Example 1 of CN113828347B:

[0082] 100g of macroporous alumina (pore volume 1.0mL / g, specific surface area 440m²) was used. 2 20g of NaY molecular sieve (silicon-to-aluminum ratio of 5) are thoroughly mixed. After uniform mixing, 6g of magnesium oxide is added, and the mixture is further mixed using a ball mill until completely homogeneous. A small amount of the mixture (10g) is placed in a rotating drum and sprayed with a 0.1% sodium bicarbonate solution for ball forming. The mixture is continuously added to adjust the moisture content and continue ball forming until balls are formed. The mixture is dried at 120℃ for 2 hours and calcined at 500℃ for 4 hours to obtain the carrier.

[0083] Dissolve 56g of lead acetate and 0.2g of silver nitrate in 70mL of water, heat the solution to 80℃ to ensure complete dissolution, and add 1g of hydrogen peroxide (30% concentration) to promote oxidation. Add 100g of carrier to a rotary evaporator and evacuate under vacuum. After the pressure reaches -0.09MPa, 70mL of impregnation solution is added for impregnation. After impregnation, dry at 120℃ for 2 hours and calcine at 500℃ for 4 hours to obtain the finished product.

[0084] The arsenic removal performance of the arsenic removal agents prepared in Examples 1-8 and Comparative Example 1 was tested using the following methods:

[0085] Test 1 (Arsenic Removal Test of Gaseous Hydrocarbons): 3 mL of the arsenic removal agent prepared in Examples 1 to 8 was respectively loaded into the reactor, and C44 with an arsenic content of 500 ppm was added under normal temperature and pressure. -C The mixed gas passes through an arsenic removal reactor with hydrogen sulfide and organic sulfur content of 100 ppm and a gas hourly space velocity of 1500 h⁻¹. After 500 hours of stable operation, the arsenic capacity, arsenic removal accuracy, and sulfur capacity were measured and are shown in Table 1.

[0086] Table 1. Test results of arsenic removal performance of gaseous hydrocarbons

[0087] sample Arsenic Arsenic removal accuracy (ppb) Sulfur capacity Example 1 18.91% 0.5 3.2% Example 2 19.22% 0.5 3.1% Example 3 19.25% 0.4 2.8% Example 4 21.72% 0.4 2.7% Example 5 22.51% 0.3 3.2% Example 6 25.74% 0.2 3.3% Example 7 26.82% 0.1 3.3% Example 8 26.88% 0.1 3.5% Comparative Example 1 21.37% 0.1 Data not measured

[0088] Test 2 (Arsenic Removal Test of Liquid Hydrocarbons): 3 mL of the arsenic removal agent prepared in Examples 1 to 8 was loaded into the reactor. Naphtha with an arsenic content of 400 ppm was passed through the arsenic removal reactor at room temperature and pressure. The hydrogen sulfide and organic sulfur contents were 100 ppm, and the liquid hourly space velocity was 2 h⁻¹. After 500 hours of stable operation, the arsenic capacity, arsenic removal accuracy, and sulfur capacity were measured and are shown in Table 2.

[0089] Table 2 Test results of arsenic removal performance of liquid hydrocarbons

[0090] sample Arsenic Arsenic removal accuracy (ppb) Sulfur capacity Example 1 17.53% 0.3 2.9% Example 2 17.25% 0.3 3.0% Example 3 20.13% 0.3 2.9% Example 4 22.74% 0.2 2.9% Example 5 22.51% 0.2 3.1% Example 6 24.38% 0.2 3.1% Example 7 25.92% 0.1 3.5% Example 8 26.11% 0.1 3.4%

[0091] As can be seen from the test data in Tables 1 and 2, the arsenic removal agents prepared in Examples 1-8 of this invention exhibit excellent performance in the removal of arsenic from both gaseous and liquid hydrocarbon feedstocks. With the increase of the active component content, both the arsenic capacity and the arsenic removal precision are significantly improved. In particular, Examples 7 and 8 show arsenic capacities of 26.82% and 26.88%, respectively, and arsenic removal precision of 0.1 ppb, significantly better than Comparative Example 1 (CN113828347B Example 1, arsenic capacity 21.37%, arsenic removal precision 0.1 ppb). This fully demonstrates that the use of lead oxide, manganese oxide, and silver oxide as ternary active components, combined with a high specific surface area alumina sphere carrier, significantly improves the arsenic capacity and arsenic removal precision of the arsenic removal agent, extending its industrial service life. Simultaneously, the arsenic removal agent of this invention also possesses a certain desulfurization capacity (sulfur capacity 2.7-3.5%), expanding its application range. More importantly, the arsenic removal agent of the present invention has a wide range of applications. It can be used for the removal of arsenic from gaseous hydrocarbon feedstocks as well as for the removal of arsine from liquid hydrocarbon feedstocks. It is particularly suitable for the precise removal of arsine from feedstocks containing alkynes, and its safety is significantly improved.

[0092] The above embodiments are merely illustrative examples to clearly illustrate the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description, and it is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An arsenic removal agent, comprising a carrier and an active component, characterized in that, The active component accounts for 35-60% of the total mass of the arsenic removal agent; wherein the active component includes lead oxide, manganese oxide, and silver oxide, the mass percentage of lead oxide is 20-25%, the mass percentage of manganese oxide is 20-25%, and the mass percentage of silver oxide is 1-5%; the molar ratio of lead, manganese, and silver in the active component is (10-15):(8-12):(0.05-2.5); the carrier is alumina spheres with a high specific surface area, and the specific surface area of ​​the carrier is 700-900 m². 2 / g, with a pore volume of 0.7-0.9mL / g; the preparation method of the carrier is as follows: hydrochloric acid solution is added to macroporous pseudoboehmite powder, then nitric acid is added for acidification, and then ammonia water and guar powder are added for neutralization to form aluminum sol. Alumina spheres are prepared by drop ball forming method. After aging, pressure filtration, washing, and drying, the high specific surface area alumina sphere carrier is obtained at 700-800℃ for 2-4h.

2. The arsenic removal agent according to claim 1, characterized in that, The hydrochloric acid solution has a mass concentration of 5-15%, the nitric acid solution has a mass concentration of 20-40%, and the ammonia solution has a mass concentration of 5-10%.

3. The arsenic removal agent according to claim 1 or 2, characterized in that, The aging time is 12-24 hours, and the aging temperature is 40-60℃; the drying temperature is 100-140℃, and the drying time is 6-10 hours.

4. A method for preparing the arsenic removal agent according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1, Carrier preparation: Hydrochloric acid solution is added to macroporous pseudoboehmite powder, then nitric acid is added for acidification, followed by the addition of ammonia and guar powder for neutralization to form aluminum sol. Alumina spheres are prepared by drop ball forming method. After aging, pressure filtration, washing, and drying, the alumina sphere carrier is calcined at 700-800℃ for 2-4 hours to obtain alumina sphere carrier with high specific surface area. Step 2, First Impregnation: Prepare a mixed salt solution of lead acetate and silver nitrate. Dissolve lead acetate and silver nitrate in water and heat to 60-90℃ to completely dissolve them. Add the carrier obtained in Step 1 to the drum and spray the mixed salt solution evenly onto the carrier for equal-volume impregnation. After drying, obtain the semi-finished arsenic removal agent. Step 3, Second Impregnation: Prepare manganese nitrate solution by dissolving manganese nitrate in water and heating to 60-90℃ to completely dissolve it; spray the manganese nitrate solution evenly onto the arsenic removal agent semi-finished product obtained in Step 2; Step 4, calcination: The product obtained in step 3 is dried at 100-140℃ for 8-12 hours, and then calcined at 450-550℃ for 4-6 hours to obtain the arsenic removal agent.

5. The preparation method according to claim 4, characterized in that, In step 1, the mass concentration of the hydrochloric acid solution is 5-15%, the mass concentration of the nitric acid is 20-40%, and the mass concentration of the ammonia solution is 5-10%.

6. The preparation method according to claim 4 or 5, characterized in that, In step 1, the aging time is 12-24 hours and the aging temperature is 40-60℃; the drying temperature is 100-140℃ and the drying time is 6-10 hours.

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