Desulfurizing agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of desulfurization, in particular to a desulfurizing agent as well as a preparation method and application thereof. The desulfurizing agent provided by the invention comprises a carrier which is boron nitride and few layers of zinc oxide loaded on the carrier in situ. The desulfurizer provided by the invention realizes high atomic utilization rate of ZnO, has excellent breakthrough sulfur capacity while having high atomic utilization rate, and effectively improves the problems of low sulfur capacity, low atomic utilization rate of zinc oxide, insufficient low-temperature activity and the like of the traditional zinc oxide desulfurizer.

Description

Technical Field

[0001] This invention relates to the field of desulfurization technology, and in particular to a desulfurizing agent, its preparation method, and its application. Background Technology

[0002] Hydrogen sulfide is a harmful gas widely found in natural gas, shale gas, and fermentation plant off-gas. It not only causes significant environmental pollution but also seriously endangers human health, necessitating timely removal after extraction. Currently, commonly used desulfurizers on the market include iron oxide desulfurizers, copper oxide desulfurizers, and zinc oxide desulfurizers; among them, zinc oxide holds an important position due to its superior thermodynamic properties in reacting with hydrogen sulfide, high desulfurization precision, stable and convenient operation, and high sulfur capacity (by weight percentage). However, existing zinc oxide desulfurizers mainly suffer from problems such as low sulfur capacity, low zinc oxide atom utilization, and insufficient low-temperature activity. Invention patent application CN119524604A lists the technical specifications of major domestically produced zinc oxide desulfurizers as shown in Table 1.

[0003] Table 1 Technical Requirements for Zinc Oxide Desulfurizer

[0004] As shown in Table 1, the zinc oxide content of domestic zinc oxide desulfurizers is very high (≥80%), but the atom utilization rate of zinc oxide is generally very low. A large amount of zinc oxide in the desulfurizers is not effectively utilized, resulting in resource waste, excessive cost, and most of them are only suitable for high temperature (220℃ and above).

[0005] Patent application CN102961959A discloses a zinc oxide desulfurizing agent prepared by extrusion of a mixture of activated zinc oxide, high-alumina powder, bentonite, calcium hydroxide, and sodium carboxymethyl cellulose. This catalyst can remove as little as 0.03 ppm of H2S from liquid propylene at room temperature, but its sulfur capacity is only 3.1%. Patent application CN1094331A discloses a method for preparing a room-temperature zinc oxide desulfurizing agent, which is mainly composed of a mixture of ZnO and iron cement. At temperatures of 20–80°C, its sulfur capacity is only about 8.6–11.7%, which is also difficult to meet the requirements for industrial application.

[0006] Based on the shortcomings of current zinc oxide desulfurizers, LIU et al. prepared a zinc-silicon composite desulfurizer using zinc acetate, tetraethyl orthosilicate, and monoethanolamine as precursors via a sol-gel method. When the active component content (mass fraction) was 30%, the sulfur penetration capacity was 96.4 mg / g, and the zinc oxide (ZnO) atom utilization rate was 81%. YANG et al. prepared a novel zinc-silicon composite desulfurizer using tetraethyl orthosilicate, ethylene glycol, and zinc nitrate as precursors via a sol-gel method. Its active component ZnO content was 57%, the sulfur capacity reached 108.9 mg / g, and the zinc oxide (ZnO) atom utilization rate was 48%. WANG et al. prepared a 3DOM-structured zinc-silicon composite desulfurizer using a colloidal template method. Its active component ZnO content was 50%, its sulfur penetration capacity reached a maximum of 170 mg / g, and the zinc oxide (ZnO) atom utilization rate was 86%.

[0007] Although loading zinc oxide onto common carriers can improve the utilization efficiency of zinc oxide components, the tendency of zinc oxide components to agglomerate and grow results in a low exposed active surface area. Therefore, it is necessary to increase the loading to achieve sulfur capacity, leading to a significant waste of zinc oxide. Thus, developing a desulfurizing agent with high sulfur capacity and high ZnO atom utilization is of paramount importance. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a desulfurizing agent, its preparation method, and its application. The desulfurizing agent provided by this invention achieves high atomic utilization of ZnO, and while maintaining high atomic utilization, it also exhibits excellent sulfur penetration capacity.

[0009] In a first aspect, the desulfurizing agent provided by the present invention comprises: a support, wherein the support is boron nitride; and a few-layer zinc oxide in situ supported on the support. The desulfurizing agent provided by the present invention uses boron nitride as a support, and by in situ loading a few-layer zinc oxide onto the boron nitride support, the interaction between the boron nitride and the in-situ loaded zinc oxide effectively improves the problems of low sulfur capacity, low zinc oxide atom utilization, and insufficient low-temperature activity of traditional zinc oxide desulfurizing agents. It achieves high atom utilization of ZnO and has a very high sulfur penetration capacity.

[0010] Preferably, the desulfurizing agent contains 5% to 95% zinc oxide by mass.

[0011] Further preferably, the zinc oxide content in the desulfurizing agent is 10%~90% by mass, preferably 10%~50% or 40%~90%. For example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. The desulfurizing agent provided by this invention operates at 45 °C and a space velocity of 5000 h⁻¹. -1Under the condition of H2S precision of 0.1 ppm, the atom utilization rate reaches 100% when the ZnO content is between 10% and 50%, and the sulfur penetration capacity reaches 292 mg / g when the ZnO content is 90%.

[0012] Preferably, the zinc oxide is loaded onto the boron nitride support in situ by mechanical ball milling.

[0013] Preferably, the zinc oxide loaded on the carrier has a hexagonal morphology; more preferably, it is a single layer and / or a double layer. In this invention, the single-layer to double-layer hexagonal zinc oxide on the carrier, especially the single-layer hexagonal zinc oxide, can significantly improve the atomic utilization rate of zinc oxide, significantly enhance the desulfurization reaction activity, and increase the sulfur capacity of the desulfurizing agent.

[0014] Preferably, the carrier is boron nitride with a few layers; more preferably, the number of layers is three to ten.

[0015] This invention uses the layered compound boron nitride as a carrier and employs a high-energy mechanical ball milling method to in-situ load zinc oxide onto the boron nitride carrier. This significantly improves upon the problems of low sulfur capacity, low atom utilization rate, and insufficient low-temperature activity found in traditional zinc oxide desulfurizers. Through the action of high-energy mechanical force, the interlayer spacing of boron nitride is opened, forming a layered structure with fewer layers, promoting the existence of zinc oxide as a highly dispersed single-layer hexagonal structure, thus achieving high atom utilization rate for ZnO.

[0016] Secondly, this invention provides a method for preparing the desulfurizing agent, comprising: mixing boron nitride and a zinc source, and ball milling them at a speed of 300-1000 r / min for 3-12 h. The desulfurizing agent provided by this invention uses boron nitride as a carrier, and employs high-energy mechanical ball milling at specific speeds and times to in-situ load the zinc source onto the boron nitride carrier, achieving high atomic utilization of ZnO and effectively improving the problems of low sulfur capacity, low zinc oxide atomic utilization, and insufficient low-temperature activity of traditional zinc oxide desulfurizing agents. Furthermore, the preparation process of the desulfurizing agent of this invention avoids the co-precipitation and calcination processes in traditional preparation methods, directly obtaining the agent through mechanical ball milling, avoiding wastewater generation, and the preparation method is simple, easy to control, has good stability, and is easy to scale up for production.

[0017] Preferably, the ball milling process is performed at a rotation speed of 600-900 r / min for 6-10 h.

[0018] Preferably, the ball-to-material ratio in the ball milling process is 14-16:1, and the ball milling process uses large agate balls with a diameter of 5-10 mm and small agate balls with a diameter of 3-4 mm.

[0019] Preferably, the ratio of the large agate balls to the small agate balls is 1:4~6. Optimizing the ball milling conditions can better promote the full opening of the boron nitride interlayer spacing and the formation of a stable few-layer structure, further enhancing the chemical interaction with ZnO, and loading it in a highly dispersed hexagonal morphology, improving atom utilization while ensuring sufficient mechanical force to increase sulfur penetration capacity.

[0020] Preferably, the zinc source is selected from one or more of zinc nitrate, zinc acetate, zinc chloride, and zinc carbonate, with zinc nitrate being the most preferred.

[0021] Thirdly, the present invention also provides the application of the desulfurizing agent or the desulfurizing agent obtained by the preparation method in the deep removal of hydrogen sulfide.

[0022] The beneficial effects of this invention are at least as follows: The deep desulfurization hexagonal zinc oxide of this invention uses the layered compound boron nitride as a carrier, and employs a high-energy mechanical ball milling method to in-situ load zinc oxide onto the boron nitride carrier. Through the action of high-energy mechanical force, the boron nitride opens the interlayer spacing, forming a few-layered layered structure. Due to the instability of the layered structure, it easily bonds with metal oxides to form strong chemical interactions, increasing the chemical interaction between ZnO and the carrier. This promotes the existence of zinc oxide as a highly dispersed single-layered hexagon, achieving high atomic utilization of ZnO. Simultaneously, the B-OH and N-OH functional groups are fully exposed at the edge positions, and the carrier exhibits certain weakly basic functional groups, which can adsorb a certain amount of hydrogen sulfide. This acts as chemisorption, achieving selective removal and realizing ultra-deep desulfurization with high sulfur capacity. Furthermore, the few-layered layered structure formed by boron nitride creates hierarchical pores, which is beneficial to the mass transfer process during desulfurization, further accelerating the desulfurization process. The desulfurizer provided by this invention avoids the co-precipitation and calcination processes in traditional preparation methods. It is directly obtained by mechanical ball milling, avoiding wastewater generation. Moreover, the preparation method is simple and easy to control, has good stability, and is easy to scale up for production. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a scanning electron microscope image of the hexagonal zinc oxide desulfurizing agent provided in Example 4 of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0027] Unless otherwise specified, the techniques or conditions described in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., without specified manufacturers, are all conventional products that can be purchased through legitimate channels. All experimental reagents and raw materials involved are commercially available products, and all reagents are analytical grade products.

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] In the following embodiments, boron nitride is hexagonal, zinc nitrate is analytical grade, and both are from Sinopharm; hydrogen sulfide standard gas is customized from Dalian Date Gas Co., Ltd.

[0030] In the following embodiments, the desulfurizing agent samples were all subjected to desulfurization performance evaluation tests, as detailed below: Table 2 Adsorption Evaluation Conditions Standard gas composition <![CDATA[1000 ppm - H2S, nitrogen balance]]> Evaluation pressure 0.15 MPa Evaluation temperature 20-100 ℃ Sample volume 1.0±0.01g airspeed <![CDATA[5000 h -1 ]]> The specific evaluation method is as follows: First, add 1.0 g of fresh desulfurizing agent to the fixed-bed reactor, purge the system with nitrogen, and then adjust the back pressure valve to stabilize the system pressure at 0.15 MPa. Evaluation is then conducted within the range of 20 to 100 °C; in this method, the evaluation is performed at 45 °C. Next, switch the gas path and introduce hydrogen sulfide standard gas into the system to begin the evaluation. The tail gas is introduced into a gas chromatograph, and tail gas samples are collected every 3 minutes. Adsorption saturation is considered complete when the hydrogen sulfide outlet concentration exceeds 0.1 ppm.

[0031] Formula for calculating breakthrough sulfur capacity: Q B (mg / g)=FtC0 / m×32÷22.4÷1000000; Among them, Q B : Desulfurizer penetration sulfur capacity, mg / g; F: Feed gas flow rate, mL / min; C0: Feed gas hydrogen sulfide concentration, ppm; t: Hydrogen sulfide penetration time, min; m: Desulfurizer mass, g.

[0032] Formula for calculating atom utilization rate: Q A (%) = (FtC0 ÷ 1000000 ÷ 22.4) / (m × C) ZnO / ×1000÷81); Among them, Q A Zinc oxide atom utilization rate, %; F: feed gas flow rate, mL / min; C0: feed gas hydrogen sulfide concentration, ppm; t: hydrogen sulfide breakthrough time, min; m: desulfurizing agent mass, g; C ZnO : Zinc oxide content in desulfurizing agent.

[0033] Example 1 This embodiment provides a desulfurizing agent for deep desulfurization of hexagonal zinc oxide, with boron nitride as the carrier; zinc oxide is loaded on the carrier, and the desulfurizing agent contains 10% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a monolayer form.

[0034] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 90:10, 9 g of BN and 2.34 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0035] Example 2 This embodiment provides a desulfurizing agent for deep desulfurization of hexagonal zinc oxide, with boron nitride as the carrier; zinc oxide is in situ loaded on the carrier, and the desulfurizing agent contains 20% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a monolayer form.

[0036] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 80:20, 8 g of BN and 4.68 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0037] Example 3 This embodiment provides a desulfurizing agent for deep desulfurization of hexagonal zinc oxide, with boron nitride as the carrier; zinc oxide is in situ loaded on the carrier, and the desulfurizing agent contains 30% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a monolayer form.

[0038] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 70:30, 7 g of BN and 7.01 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. Then, the desulfurizing agent was loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0039] Example 4 This embodiment provides a deep desulfurization desulfurizing agent using hexagonal zinc oxide, with boron nitride as the carrier. Zinc oxide is in-situ loaded onto the carrier. The desulfurizing agent contains 40% zinc oxide by mass, and the zinc oxide is nano-sized hexagonal zinc oxide. Figure 1 As shown, the synthesized nanoscale hexagonal zinc oxide is loaded onto boron nitride in the form of a monolayer.

[0040] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: According to the mass ratio of BN:ZnO = 60:40, 6 g of BN and 9.35 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was processed by ball milling at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. Then, the desulfurizing agent was loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0041] Example 5 This embodiment provides a desulfurizing agent for deep desulfurization of hexagonal zinc oxide, with boron nitride as the carrier; zinc oxide is in situ loaded on the carrier, and the desulfurizing agent contains 50% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a monolayer form.

[0042] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 50:50, 5 g of BN and 11.69 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0043] Example 6 The desulfurizing agent for deep desulfurization of hexagonal zinc oxide provided in this embodiment uses boron nitride as the carrier; zinc oxide is in situ loaded on the carrier, and the desulfurizing agent contains 60% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in single-layer and double-layer forms.

[0044] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 40:60, 4 g of BN and 14.03 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0045] Example 7 The desulfurizing agent for deep desulfurization of hexagonal zinc oxide provided in this embodiment uses boron nitride as the carrier; zinc oxide is loaded in situ on the carrier, and the desulfurizing agent contains 70% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a double-layer form.

[0046] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 30:70, 3 g of BN and 16.37 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was processed by ball milling at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. Then, the desulfurizing agent was loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0047] Example 8 The desulfurizing agent for deep desulfurization of hexagonal zinc oxide provided in this embodiment uses boron nitride as the carrier; zinc oxide is in situ loaded on the carrier, and the desulfurizing agent contains 80% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a double-layer form.

[0048] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 20:80, 2 g of BN and 18.71 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0049] Example 9 The desulfurizing agent for deep desulfurization of hexagonal zinc oxide provided in this embodiment uses boron nitride as the carrier; zinc oxide is loaded in situ on the carrier, and the desulfurizing agent contains 90% zinc oxide by mass. The zinc oxide is nano-sized hexagonal zinc oxide and is loaded on boron nitride in a double-layer form.

[0050] The preparation method of the hexagonal zinc oxide desulfurizing agent for deep desulfurization provided in this embodiment is as follows: Based on a mass ratio of BN:ZnO = 10:90, 1 g of BN and 21.04 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent product. The sample was then pressed into tablets and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0051] Comparative Example 1 The method was the same as in Example 1, except that: 23.38 g of zinc nitrate was placed in a stainless steel ball mill jar by mass ratio, along with 10 large agate balls (8 mm) and 50 small agate balls (3 mm). The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent. The sample was then tableted and crushed to obtain particles with a diameter of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced. The sulfur absorption capacity was tested using the evaluation method described above.

[0052] Comparative Example 2 The method was the same as in Example 1, except that: according to the mass ratio of BN:ZnO = 60:40, 6 g of BN and 9.35 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar, and the mixture was milled at 800 r / min for 2 h to obtain the desulfurizing agent. The sample was then tableted and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0053] Comparative Example 3 The method was the same as in Example 1, except that: according to the mass ratio of BN:ZnO = 60:40, 6 g of BN and 9.35 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 200 r / min for 8 h to obtain the desulfurizing agent. The sample was then tableted and crushed to obtain particles with a particle size of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced into it. The sulfur absorption capacity was tested using the evaluation method described above.

[0054] Comparative Example 4 The method was the same as in Example 1, except that: by mass ratio of SiO2:ZnO = 60:40, 6 g of SiO2 and 9.35 g of zinc nitrate were placed in a stainless steel ball mill jar. Ten large agate balls (8 mm) and 50 small agate balls (3 mm) were added to the jar. The mixture was milled at 800 r / min for 8 h to obtain the desulfurizing agent. The sample was then tableted and crushed to obtain particles with a diameter of 1 mm. The desulfurizing agent was then loaded into a fixed bed, and sulfur-containing gas was introduced. The sulfur absorption capacity was tested using the evaluation method described above.

[0055] Table 3 Results of hydrogen sulfide removal agent breakthrough sulfur capacity determination (Test temperature 45 ℃, outlet accuracy 0.1 ppm) Sample number ZnO loading (%) Sulfur penetration capacity (mg / g) ZnO atom utilization rate (%) Example 1 10 42 106.3 Example 2 20 82 103.8 Example 3 30 122 102.9 Example 4 40 161 101.9 Example 5 50 201 101.8 Example 6 60 228 96.2 Example 7 70 247 89.3 Example 8 80 272 86.1 Example 9 90 292 82.1 Comparative Example 1 100 138 34.9 Comparative Example 2 40 94 59.5 Comparative Example 3 40 102 64.5 Comparative Example 4 40 72 45.6 According to the test data of Examples 1 to 9 in Table 3, the hexagonal zinc oxide deep desulfurizer of this application exhibits good desulfurization effect from 10% to 90% ZnO content, and the penetration capacity of sulfur continuously increases. From 10% to 50% ZnO content, the ZnO atom utilization rate exceeds 100%, and the tested hydrogen sulfide adsorption capacity is slightly higher than the theoretical value. This is because the BN carrier itself has a certain degree of weak alkalinity, which can adsorb a certain amount of hydrogen sulfide, achieving selective removal through chemisorption. As the ZnO content increases from 60% to 100%, the ZnO atom utilization rate shows a slow decreasing trend. Comparative Example 1 uses pure zinc oxide, and its atom utilization rate is only 34.9%, which is far lower than the hexagonal zinc oxide composition provided in the embodiments of this invention. Comparative Example 2 reduced the ball mill processing time from 8 h to 2 h, and Comparative Example 3 reduced the ball mill speed from 800 r / min to 200 r / min. Both reductions were achieved by decreasing the mechanical force, which reduced the chemical interaction between ZnO and the support, decreased the specific surface area, and consequently reduced the atom utilization rate of ZnO, thus lowering the sulfur penetration capacity of the hydrogen sulfide removal agent. Comparative Example 4 used silicon oxide-supported zinc oxide, with an atom utilization rate of only 45.6%, far lower than the hexagonal zinc oxide composition provided in the embodiments of this invention.

[0056] Table 4. Results of Nitrogen Physical Adsorption-Specific Surface Area Test for Hydrogen Sulfide Removal Agent Sample number <![CDATA[BET(m 2 / g)]]> Example 4 206 Comparative Example 1 35 Comparative Example 2 86 Comparative Example 3 95 Comparative Example 4 260 According to the specific surface area test data in Table 4, the specific surface area in Example 4 is 206 m² when the ZnO content is 40%. 2 / g, while the specific surface area of ​​Comparative Example 4 using silicon oxide-supported zinc oxide was 260 m². 2 / g. Although the specific surface area of ​​Comparative Example 4 is higher than that of Example 4, its sulfur penetration capacity and zinc oxide atom utilization rate are much lower than those of Example 4. This is because although silicon oxide has a high specific surface area, it lacks the interaction force with zinc oxide. In contrast, Example 4 uses high-energy mechanical force to open the interlayer spacing of boron nitride, forming a few-layered layered structure. Due to the instability of the layered structure, it easily bonds with ZnO to form a strong chemical interaction, causing zinc oxide to exist as a highly dispersed monolayer hexagon, thus achieving high ZnO atom utilization rate. In addition, the few-layered layered structure formed by boron nitride enables the existence of hierarchical pores, which is beneficial to the mass transfer process in the desulfurization process and further accelerates the desulfurization process.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A desulfurizing agent, characterized in that, include: The support is boron nitride; And a few layers of zinc oxide loaded in situ on the carrier.

2. The desulfurizing agent according to claim 1, characterized in that, The desulfurizing agent contains 5% to 95% zinc oxide by mass.

3. The desulfurizing agent according to claim 2, characterized in that, The desulfurizing agent contains 10% to 90% zinc oxide by mass, preferably 10% to 50% or 40% to 90%.

4. The desulfurizing agent according to any one of claims 1-3, characterized in that, The zinc oxide loaded on the carrier has a hexagonal morphology; preferably, it has a single layer and / or a double layer.

5. The desulfurizing agent according to any one of claims 1-4, characterized in that, The carrier is boron nitride with a few layers; preferably, the number of layers is three to ten.

6. A method for preparing the desulfurizing agent according to any one of claims 1-5, characterized in that, include: Boron nitride and zinc source were mixed and ball-milled at a speed of 300~1000 r / min for 3~12 h.

7. The method for preparing the desulfurizing agent according to claim 6, characterized in that, The ball milling process is performed at a speed of 600-900 r / min for 6-10 h.

8. The method for preparing the desulfurizing agent according to claim 6 or 7, characterized in that, The ball-to-material ratio in the ball milling process is 14-16:1, and the ball milling process uses large agate balls with a diameter of 5-10 mm and small agate balls with a diameter of 3-4 mm. Preferably, the ratio of the large agate ball to the small agate ball is 1:4 to 6.

9. The method for preparing the desulfurizing agent according to any one of claims 6-8, characterized in that, The zinc source is selected from one or more of zinc nitrate, zinc acetate, zinc chloride, and zinc carbonate.

10. The application of the desulfurizing agent according to any one of claims 1-5 or the desulfurizing agent obtained by the preparation method according to any one of claims 6-9 in the deep removal of hydrogen sulfide.

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