Application of a NiCe-SN catalyst in the resource-based synthesis of ethyl mercaptan from hydrogen sulfide

Abstract

The present invention discloses an application of a NiCe-SN catalyst in the resource-based synthesis of ethanethiol from hydrogen sulfide. The NiCe-SN catalyst is prepared by adding a gallium source during the preparation of SBA-15, placing the prepared molecular sieve in concentrated nitric acid to separate the gallium element from the skeleton to generate silanol nests, and then loading Ce and Ni on the molecular sieve. The catalyst has excellent anti-carbon deposition performance due to the confinement effect and the oxygen storage function of Ce. In the process of synthesizing ethanethiol from ethylene and hydrogen sulfide, the activity and stability of the catalyst are greatly improved compared with the Ga-SBA-15 catalyst, and the service life of the catalyst is extended.

Description

Technical Field

[0001] The invention relates to application of a NiCe-SN catalyst in resource-based synthesis of ethyl mercaptan from hydrogen sulfide, belonging to the technical field of catalyst preparation and application. Background Art

[0002] Hydrogen sulfide, a typical toxic and malodorous gas, not only harms the atmospheric environment but also poses a significant threat to human health. The Claus process, currently the mainstream method for hydrogen sulfide treatment, has the main drawbacks of low added value and suboptimal treatment results. Ethyl mercaptan synthesis, however, offers a more attractive path for hydrogen sulfide resource recovery.

[0003] Ethyl mercaptan is an important chemical intermediate in the production of pesticides, herbicides, and pharmaceuticals. Currently, the primary process for industrial-scale production of ethyl mercaptan involves adding hydrogen sulfide to ethylene in the presence of an acid catalyst. Various acid catalysts, such as Lewis acids, γ-alumina, and ion exchange resins, have been investigated for this reaction. However, these existing methods face challenges such as environmental pollution, partial conversion, and low selectivity for ethyl mercaptan. Therefore, efficient resource-based synthesis of ethyl mercaptan from hydrogen sulfide remains a worthy research topic.

[0004] Due to the properties of the raw materials, side reactions often occur during the ethylene-to-ethanethiol synthesis process. Simultaneously improving the activity and selectivity of molecular sieves is crucial for ethanethiol synthesis. While appropriately increasing the strong acid sites of the molecular sieve can enhance reaction activity and increase ethanethiol conversion, excessively high strong acid sites can also reduce selectivity and increase byproduct formation. Adjusting the catalyst's acidity and pore size can effectively balance activity and selectivity in the catalytic reaction while also extending catalyst life. Summary of the Invention

[0005] The present invention provides a preparation method of a NiCe-SN catalyst and application thereof in catalyzing the addition reaction of ethylene and hydrogen sulfide to prepare ethyl mercaptan. The catalyst preparation process of the present invention improves the activity and stability of the catalyst and increases the life of the catalyst.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] 1. Dissolve 2-3 g of template agent Pluronic P123 in deionized water, stir and mix, then add 0.3-0.4 g of gallium salt and 4.5-5.0 g of ethyl orthosilicate in sequence, stir at room temperature for 15-17 hours, then stir at 40-60°C for 24-28 hours, then place the mixture in an autoclave and crystallize at 80-90°C for 48-60 hours, filter, wash, dry at 60-70°C overnight, and then calcine at 550-700°C to obtain Ga-SBA-15;

[0008] 2. Place 1-2 g of Ga-SBA-15 in a 12-14 mol / L nitric acid solution, stir at 90-100° C. for 12-15 hours, separate the solid and liquid, wash the solid until neutral, and then dry it at 100-120° C.; use an equal volume impregnation method to immerse the dried solid in a solution containing a cerium salt and a nickel salt, ultrasonicate for 15-20 minutes, dry it, treat it in an oxygen atmosphere at 300-350° C. for 2-3 hours, and then treat it in a H2 atmosphere at 600-700° C. for 2-3 hours to obtain a NiCe-SN catalyst;

[0009] The nickel loading is 3-5% by mass, and the cerium loading is 3-5% by mass;

[0010] 3. Place the NiCe-SN catalyst in a tubular furnace reactor and introduce a mixture of ethylene and hydrogen sulfide at 240-260°C, 1.5-1.7 MPa, and a gas hourly space velocity of 250-300 h -1 Ethyl mercaptan synthesis was carried out under the following conditions.

[0011] The present invention adds a gallium source during the traditional SBA-15 preparation process, then places the prepared molecular sieve in concentrated nitric acid to separate the gallium element from the skeleton to form silanol nests, and then loads Ce and Ni on the molecular sieve. The catalyst of the present invention has excellent anti-carbon deposition performance due to the confinement effect and the oxygen storage function of Ce. In the process of synthesizing ethanethiol from ethylene and hydrogen sulfide, the activity and stability of the catalyst are greatly improved compared with the Ga-SBA-15 catalyst, and the service life of the catalyst is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is the N2 adsorption isotherm of the catalyst used in Example 1-2;

[0013] Figure 2 is the infrared spectrum of the catalyst used in Example 1-2. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below through examples, but the protection scope of the present invention is not limited to the contents described above. Example 1

[0015] 1. Dissolve 2 g of template agent Pluronic P123 in 80 mL of deionized water, stir for 4 h, add 0.3 g of gallium nitrate hydrate, continue stirring for 0.5 h, add 4.8 g of tetraethyl orthosilicate, stir at room temperature for 15 h, stir at 45 ° C for 28 h, and then place the mixture in an autoclave for crystallization at 90 ° C for 48 h. Filter, wash the solid with deionized water, dry at 60 ° C overnight, and then calcine at 550 ° C for 5 h to obtain Ga-SBA-15;

[0016] 2. Place 1g of Ga-SBA-15 in a 13mol / L nitric acid solution, stir at 100℃ for 12h, filter, wash the solid with deionized water until neutral, and dry at 100℃ (deGa-SBA-15); use the equal volume impregnation method to place the dried solid in a solution containing cerium salt and nickel salt for 12h (nickel loading is 5wt%, cerium loading is 5wt%), ultrasonicate for 15min, dry at 60℃, and place 0.4g of the dried solid in a tubular furnace reactor, treat at 350℃ in an oxygen atmosphere for 2h, and then treat at 700℃ in a H2 atmosphere for 2h to obtain NiCe-SN catalyst (CeNi / deGa-SBA-15);

[0017] The N2 adsorption isotherms of the intermediates Ga-SBA-15 and deGa-SBA-15 are shown in Figure 1 As can be seen from the figure, the basic skeleton of the catalyst is not destroyed after the acid treatment of Ga-SBA-15, which provides conditions for the stable loading of metals; the infrared spectrum of NiCe-SN catalyst is shown in Figure 2 The shaded part in the figure belongs to the silanol nest, indicating that the silanol nest is generated on the surface of the catalyst after gallium removal. The silanol nest of the catalyst decreases after metal loading, indicating that the loaded metal is successfully combined with the silanol nest.

[0018] 3. A mixture of ethylene and hydrogen sulfide (volume ratio 1:3) was introduced into the tubular furnace reactor at a flow rate of 10 mL / min at 240 °C, 1.5 MPa, and a gas hourly space velocity of 300 h -1 Ethyl mercaptan synthesis was carried out under the following conditions. After 3 hours of reaction, the ethylene conversion rate was 90.15% and the ethyl mercaptan selectivity was 75.06%. After continuous operation for 200 hours, the conversion rate was 85.72% and the selectivity was 73.28%.

[0019] At the same time, Ga-SBA-15 prepared in step 1 and deGa-SBA-15 prepared in step 2 were used as control catalysts for ethanethiol synthesis under the same conditions as above. The results showed that under the action of Ga-SBA-15, the ethylene conversion rate was 55.28% and the ethanethiol selectivity was 60.36%. After continuous operation for 30 hours, the ethylene conversion rate was 26.96% and the ethanethiol selectivity was 62.78%.

[0020] Under the action of deGa-SBA-15, the ethylene conversion rate was 18.36% and the ethanethiol selectivity was 70.12%. After continuous operation for 30 hours, the ethylene conversion rate was 8.67% and the ethanethiol selectivity was 78.17%. Example 2

[0021] 1. Dissolve 3 g of template agent Pluronic P123 in 90 mL of deionized water, stir for 3 h, add 0.4 g of gallium nitrate hydrate, continue stirring for 1 h, add 5 g of tetraethyl orthosilicate, stir at room temperature for 15 h, stir at 55 ° C for 24 h, then place the mixture in an autoclave and crystallize at 85 ° C for 50 h, filter, wash the solid with distilled water, dry at 70 ° C overnight, and calcined at 600 ° C for 5 h to obtain Ga-SBA-15;

[0022] 2. Place 1g of Ga-SBA-15 in a 13mol / L nitric acid solution, stir at 110°C for 10h, filter, wash the solid until neutral, and dry at 110°C (deGa-SBA-15); use an equal volume impregnation method to place the dried solid in a solution containing cerium salt and nickel salt for 12h (nickel loading is 3wt%, cerium loading is 3wt%), ultrasonicate for 17min, and dry at 70°C. Place 0.5g of the dried solid in a tubular furnace reactor and treat it at 300°C in an oxygen atmosphere for 2h, and then at 600°C in a H2 atmosphere for 2h to obtain a NiCe-SN catalyst;

[0023] 3. A mixture of ethylene and hydrogen sulfide (volume ratio 1:3) was introduced into the tubular furnace reactor at a flow rate of 12.5 mL / min at 260 °C, 1.7 MPa, and a gas hourly space velocity of 250 h -1 Ethyl mercaptan synthesis was carried out under the following conditions: after 3 h of reaction, the ethylene conversion rate was 88.13% and the ethyl mercaptan selectivity was 72.30%; after 200 h of continuous operation, the conversion rate decreased by 5% and the selectivity decreased by 2%.

[0024] At the same time, Ga-SBA-15 prepared in step 1 and deGa-SBA-15 prepared in step 2 were used as control catalysts for ethanethiol synthesis under the same conditions as above. The results showed that under the action of Ga-SBA-15, the ethylene conversion rate was 55.67% and the ethanethiol selectivity was 62.25%. After continuous operation for 30 hours, the ethylene conversion rate decreased by about 32% and the ethanethiol selectivity decreased by 10%.

[0025] Under the action of deGa-SBA-15, the ethylene conversion rate was 17.81% and the ethanethiol selectivity was 70.69%. After 30 hours of continuous operation, the ethylene conversion rate decreased by about 10% and the ethanethiol selectivity decreased by 8%.

Claims

1. Application of NiCe-SN catalyst in the resource synthesis of hydrogen sulfide to prepare ethanethiol; The NiCe-SN catalyst is prepared by dissolving 2-3g of template agent Pluronic P123 in deionized water, stirring and mixing, then adding 0.3-0.4g of gallium salt and 4.5-5.0g of tetraethyl orthosilicate in sequence, stirring at room temperature for 15-17h, stirring at 40-60°C for 24-28h, and then placing the mixture in a high-pressure reactor for crystallization at 80-90°C, filtering, washing, drying overnight, and then calcining at 550-700°C to obtain Ga-SBA-15; Ga-SB -15 is placed in a nitric acid solution, stirred at 90-100°C for 12-15 hours, solid-liquid separation is performed, the solid is washed until neutral and then dried; using an equal volume impregnation method, the dried solid is placed in a solution containing a cerium salt and a nickel salt and impregnated, ultrasonicated for 15-20 minutes, dried, treated in an oxygen atmosphere at 300-350°C for 2-3 hours, and then treated in a H2 atmosphere at 600-700°C for 2-3 hours to obtain the product; The nickel loading is 3-5%, and the cerium loading is 3-5%.

2. The use according to claim 1, characterized in that: The concentration of nitric acid solution is 12-14 mol / L.

3. The use according to claim 1, characterized in that: Using ethylene and hydrogen sulfide as raw materials, at 240-260℃, 1.5-1.7MPa pressure, and gas hourly space velocity of 250-300h -1 Ethyl mercaptan was synthesized under the conditions of .

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