A catalyst resistant to sulfur poisoning, its preparation method and application

Abstract

The application provides a sulfur-poisoning-resistant catalyst and a preparation method and application thereof, and belongs to the technical field of tetrahydrothiophene production processes, and aims to solve the technical problems of low utilization rate, poor stability and difficult recycling of active alumina. The preparation method of the sulfur-poisoning-resistant catalyst comprises the following steps: (1) dissolving a soluble aluminum salt and an inorganic binder in a solvent I to prepare an inner layer coating solution, spraying the inner layer coating solution on the surface of spherical aggregates and performing drying treatment; (2) dissolving an active component in a solvent II to prepare an outer layer coating solution, and spraying the outer layer coating solution on the surface of the spherical aggregates prepared in the step (1); and (3) performing roasting activation on the spherical aggregates obtained in the step (2) to obtain the sulfur-poisoning-resistant catalyst. The synthesis process of the sulfur-poisoning-resistant catalyst is simple and environment-friendly, the synthesis cost is low, the maximum yield of tetrahydrothiophene is 99.5%, the stability of the catalyst is remarkable, and the catalyst carrier can be recycled.

Description

Technical Field

[0001] This invention belongs to the technical field of tetrahydrothiophene production process, and particularly relates to an anti-sulfur poisoning catalyst, its preparation method and application. Background Technology

[0002] Tetrahydrothiophene is an important sulfur-containing saturated heterocyclic compound and a high-value-added fine organic chemical raw material. It is mainly used as an odorant and warning agent for gaseous fuels such as city gas and natural gas, and can also be used as a raw material in the production of pharmaceuticals, pesticides, and photochemicals. Currently, according to international standards, tetrahydrothiophene must be used as an odorant for gases such as city gas and natural gas. Given that China currently relies heavily on imports for tetrahydrothiophene, there is a huge market potential for it in China.

[0003] There are three main methods for producing tetrahydrothiophene: (1) Thiophene catalytic hydrogenation method, which uses thiophene as raw material and synthesizes tetrahydrothiophene through catalytic hydrogenation reduction reaction. This process has problems such as high price of thiophene raw material, high price of catalyst, complex process conditions, high production cost, and no obvious market advantage; (2) 1,4-dichlorobutane direct thiolation method, which uses 1,4-dichlorobutane and sodium sulfide containing water of crystallization as raw materials and ethanol as solvent, and generates tetrahydrothiophene under the action of iodine catalyst. Water is generated in this reaction process, and it is difficult to separate it from the product; (3) Sulfolane hydrogenation method, which generates tetrahydrothiophene by reacting sulfolane and hydrogen under the catalysis of catalyst. This reaction process involves hazardous chemical hydrogen, and continuous production cannot be achieved in this process; (4) Tetrahydrofuran direct thiolation method, in which tetrahydrofuran reacts directly with hydrogen sulfide to generate tetrahydrothiophene under the action of solid acid catalyst.

[0004] The traditional process for the direct sulfidation synthesis of tetrahydrothiophene from tetrahydrofuran uses molybdenum disulfide or palladium supported on activated carbon as a catalyst, and then reduces thiophene with hydrogen to produce tetrahydrothiophene. However, existing catalysts suffer from disadvantages such as low tetrahydrothiophene yield, poor catalyst recyclability, and poor catalyst stability. Therefore, developing economical and efficient new catalysts is a research hotspot in the tetrahydrothiophene production process. Patent publication number CN117899507A discloses a synthesis process for high-purity tetrahydrothiophene. The catalyst preparation method involves: first, fully dissolving activated alumina in a transition metal nitrate solution; evaporating the solution to dryness; then soaking it in a saturated ammonium carbonate solution; drying it; placing it in a heteropoly acid solution; and sequentially evaporating the solution to dryness, drying, washing with water, and drying again. Finally, the catalyst is activated at 450-500℃ under nitrogen protection to obtain the activated catalyst. Patent publication number CN117000264A discloses a catalyst, preparation method, and application for the direct sulfidation of tetrahydrofuran to tetrahydrothiophene. This catalyst involves mixing a copper-containing compound, a heteropolyacid salt, and an alumina precursor, stirring, and microwaving the mixture to obtain a sol-gel. The sol-gel is then dried to obtain a catalyst precursor, which is subsequently calcined to obtain the catalyst. Both of these catalysts utilize heteropolyacids supported on activated alumina, which improves catalytic activity and selectivity to some extent. However, the prepared catalysts are prone to agglomeration, resulting in low utilization of the activated alumina. Furthermore, the catalysts have short lifespans and are easily deactivated. After deactivation, the catalyst becomes waste, making recovery difficult. Summary of the Invention

[0005] To address the technical problems of low utilization rate, poor stability, and difficulty in recycling of activated alumina, this invention proposes an anti-sulfur poisoning catalyst, its preparation method, and its application. The synthesis process of the anti-sulfur poisoning catalyst is simple and environmentally friendly, with low synthesis cost, a maximum yield of tetrahydrothiophene of 99.5%, significant catalyst stability, and recyclable catalyst support.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0008] (1) Dissolve soluble aluminum salt and inorganic binder in solvent I to prepare inner coating liquid, then spray the inner coating liquid onto the surface of spherical aggregate and dry it, and then calcine to activate it.

[0009] (2) Dissolve the active component in solvent II to prepare an outer coating liquid, spray it onto the surface of the spherical aggregate obtained in step (1), and dry it to obtain an anti-sulfur poisoning catalyst.

[0010] The soluble aluminum salt is one of sodium aluminate, potassium aluminate, aluminum sulfate, aluminum nitrate, or potassium aluminum sulfate; the inorganic binder is one of aluminum hydroxide, iron hydroxide, copper hydroxide, zinc hydroxide, nickel hydroxide, calcium hydroxide, or barium hydroxide.

[0011] The concentration of soluble aluminum salt in the inner coating solution is 5-50 wt%, and the concentration of inorganic binder is 5-20 wt%.

[0012] The spherical aggregate is one of ceramic spheres, silicon dioxide spheres, silicon carbide spheres, and alumina spheres, wherein the outer diameter of the spherical aggregate is 1-5 mm.

[0013] The spraying method in steps (1) and (2) is as follows: the spherical aggregate is placed in the granulator, and the inner coating liquid and the outer coating liquid are coated on the surface of the spherical aggregate by air spraying / airless spraying.

[0014] The active component is a non-precious metal salt, which is one of tin oxalate, tin sulfate, niobium oxalate, cobalt oxalate, cobalt sulfate, ferric sulfate, zinc oxalate, zinc sulfate, magnesium chloride, magnesium sulfate, manganese oxalate, vanadium oxalate, or chromium oxalate.

[0015] The concentration of the active component in the coating solution is 5-50 wt%.

[0016] The calcination activation temperature is 700℃-1200℃, the holding time is 1h-24h, and the heating rate is 5-25℃ / min.

[0017] An application of an anti-sulfur poisoning catalyst is characterized in that it is used to catalyze the reaction of tetrahydrofuran and hydrogen sulfide to prepare tetrahydrothiophene. The molar ratio of tetrahydrofuran to hydrogen sulfide is 1.0:(1.1-2.5), and the catalytic reaction temperature is 240℃-290℃.

[0018] The beneficial effects of this invention are as follows: The synthesis process of the anti-sulfur poisoning catalyst of this invention is simple and environmentally friendly, with low synthesis cost, a maximum yield of tetrahydrothiophene of 99.5%, significant catalyst stability, and recyclable catalyst support. First, spherical aggregates are inner-layered and then calcined at high temperature, resulting in a uniform multi-level porous r-Al2O3 layer covering the aggregate surface, leading to a rich pore structure on the catalyst surface. Subsequently, an outer layer is applied, ensuring a uniform distribution of active components on the surface of the multi-level porous r-Al2O3 layer. Compared with physically supported catalysts, the catalyst prepared by this patent has the advantage of a more pronounced pore structure in the r-Al2O3 layer on the catalyst surface, while effectively reducing catalyst deactivation rate. Compared with catalysts prepared by in-situ molding methods, the catalyst prepared by this patent has the advantage of improving the utilization efficiency of active components and r-Al2O3 precursors in the catalyst raw materials. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The GC-MS spectrum of the product prepared in the catalyst-catalyzed synthesis of tetrahydrothiophene in Example 4 is shown.

[0021] Figure 2 The GC-MS spectrum of the product prepared in the catalyst-catalyzed synthesis of tetrahydrothiophene for Comparative Example 1 is shown. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0023] Example 1

[0024] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0025] (1) Dissolve sodium aluminate and aluminum hydroxide in water to prepare an inner coating solution. The concentration of sodium aluminate in the inner coating solution is 50 wt%, and the concentration of aluminum hydroxide is 5 wt%.

[0026] (2) Place the ceramic ball (outer diameter 2mm) in the disc granulator, and then spray the inner coating liquid onto the surface of the ceramic ball by air spraying. After the spraying is completed, place the sample in a forced-air drying oven and dry it at a drying temperature of 100℃.

[0027] (3) Place the sample in a tube furnace, raise the temperature at a rate of 5℃ / min, raise it to 700℃, and hold it at that temperature for 1 hour.

[0028] (4) Dissolve tin oxalate in water to prepare an outer coating solution with a concentration of 5 wt%;

[0029] (5) The sample obtained in step (3) is placed in the disc granulator again, and then the outer coating liquid is sprayed onto the surface of the ceramic ball by air spraying. After the spraying is completed, the sample is placed in the blower oven and dried at a drying temperature of 100°C to obtain the anti-sulfur poisoning catalyst.

[0030] Application Example 1

[0031] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:1.1 were reacted with the anti-sulfur poisoning catalyst prepared in Example 1 to produce tetrahydrothiophene at a catalytic temperature of 240°C.

[0032] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 99.5%; the deactivation rate was 0.01% / h.

[0033] Example 2

[0034] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0035] (1) Dissolve aluminum sulfate and ferric hydroxide in water to prepare an inner coating solution. The concentration of aluminum sulfate in the inner coating solution is 30 wt%, and the concentration of ferric hydroxide is 5 wt%.

[0036] (2) Place the alumina balls (outer diameter 3mm) in a disc granulator, and then spray the inner coating liquid onto the surface of the ceramic balls by air spraying. After the spraying is completed, place the sample in a forced-air oven and dry it at a drying temperature of 120℃.

[0037] (3) Place the sample in a tube furnace, heat it at a rate of 10℃ / min, raise it to 700℃, and hold it at that temperature for 2 hours.

[0038] (4) Dissolve niobium oxalate in water to prepare an outer coating solution with a concentration of 18 wt%;

[0039] (5) The sample obtained in step (3) is placed in the disc granulator again, and then the outer coating liquid is sprayed onto the surface of the ceramic ball by air spraying. After the spraying is completed, the sample is placed in the blower oven and dried at a drying temperature of 100°C to obtain the anti-sulfur poisoning catalyst.

[0040] Application Example 2

[0041] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:1.2 were reacted under the catalysis of the anti-sulfur poisoning catalyst prepared in Example 2 to produce tetrahydrothiophene at a catalytic reaction temperature of 270°C.

[0042] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 99.5%; the deactivation rate was 0.01% / h.

[0043] Example 3

[0044] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0045] (1) Dissolve aluminum nitrate and zinc hydroxide in water to prepare an inner coating solution. The concentration of aluminum nitrate in the inner coating solution is 25 wt%, and the concentration of zinc hydroxide is 20 wt%.

[0046] (2) Place silica balls (outer diameter 5mm) in a disc granulator, and then spray the inner coating liquid onto the surface of the ceramic balls by air spraying. After spraying, place the sample in a forced-air oven and dry at a drying temperature of 150℃.

[0047] (3) Place the sample in a tube furnace, raise the temperature at a rate of 15℃ / min, raise it to 1200℃, and hold it at that temperature for 12h.

[0048] (4) Dissolve cobalt oxalate in water to prepare an outer coating solution with a concentration of 15 wt%;

[0049] (5) The sample obtained in step (3) is placed in the disc granulator again, and then the outer coating liquid is sprayed onto the surface of the ceramic ball by airless spraying. After the spraying is completed, the sample is placed in the blower oven and dried at a drying temperature of 120°C to obtain the anti-sulfur poisoning catalyst.

[0050] Application Example 3

[0051] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:1.8 were reacted under the catalysis of the anti-sulfur poisoning catalyst prepared in Example 3 to produce tetrahydrothiophene at a catalytic reaction temperature of 290°C.

[0052] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 99.1%; the deactivation rate was 0.009% / h.

[0053] Example 4

[0054] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0055] (1) Dissolve potassium aluminum sulfate and barium hydroxide in water to prepare an inner coating solution. The concentration of potassium aluminum sulfate in the inner coating solution is 50 wt%, and the concentration of zinc hydroxide is 5 wt%.

[0056] (2) Place silica balls (outer diameter 1 mm) in a disc granulator, and then spray the inner coating liquid onto the surface of the ceramic balls by air spraying. After spraying, place the sample in a forced-air oven and dry it at a drying temperature of 150°C.

[0057] (3) Place the sample in a tube furnace, raise the temperature at a rate of 25℃ / min, raise it to 1200℃, and hold it at the temperature for 24 hours.

[0058] (4) Dissolve cobalt sulfate in water to prepare an outer coating solution with a concentration of 35 wt%;

[0059] (5) The sample obtained in step (3) is placed in the disc granulator again, and then the outer coating liquid is sprayed onto the surface of the ceramic ball by air spraying. After the spraying is completed, the sample is placed in the blower oven and dried at a drying temperature of 150°C to obtain the anti-sulfur poisoning catalyst.

[0060] Application Example 4

[0061] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:2.5 were reacted under the catalysis of the anti-sulfur poisoning catalyst prepared in Example 4 to produce tetrahydrothiophene at a reaction temperature of 290°C.

[0062] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 99.2%; the deactivation rate was 0.015% / h.

[0063] Comparative Example 1

[0064] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0065] (1) Dissolve potassium aluminum sulfate, cobalt sulfate and barium hydroxide in water to prepare a coating solution. The concentration of potassium aluminum sulfate in the coating solution is 50 wt%, the concentration of zinc hydroxide is 5 wt%, and the concentration of cobalt sulfate is 35 wt%.

[0066] (2) Place silica balls (outer diameter 1 mm) in a disc granulator, and then spray the coating liquid onto the silica surface by air spraying. After spraying, place the sample in a forced-air oven and dry it at a drying temperature of 150°C.

[0067] (3) Place the sample obtained in step (2) into the disc granulator again, and then spray the coating liquid onto the surface of the silica balls by air spraying. After the spraying is completed, place the sample in a forced-air oven and dry it at a drying temperature of 150°C.

[0068] (4) The sample was placed in a tube furnace and heated at a rate of 25°C / min until it reached 1200°C. The temperature was held for 24 hours to obtain the catalyst.

[0069] Comparative Application Example 1

[0070] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:2.5 were reacted with the catalyst prepared in Comparative Example 1 to produce tetrahydrothiophene at a catalytic temperature of 290℃.

[0071] The initial tetrahydrothiophene yield of the catalyst was 98.2%; the deactivation rate was 0.2% / h.

[0072] The tetrahydrothiophene prepared using gas chromatography-mass spectrometry (GC-MS) corresponding to Example 4 and Comparative Application Example 1, such as Figure 1 and 2As shown in Tables 1 and 2, the content test results indicate that the main component in the tetrahydrothiophene product is tetrahydrothiophene. In Application Example 4, the effective content of tetrahydrothiophene is higher than that in Comparative Application Example 1. Analysis of the results in Tables 1 and 2 demonstrates that the catalyst prepared by coating spherical aggregates one by one with the two coating solutions exhibits superior surface-active components and physicochemical structural characteristics.

[0073] Table 1. Results of content analysis test in Application Example 4.

[0074]

[0075] Table 2 compares the content analysis test results of Application Example 1.

[0076]

[0077]

[0078] Example 5

[0079] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0080] (1) Dissolve potassium aluminum sulfate and calcium hydroxide in water to prepare an inner coating solution. The concentration of potassium aluminum sulfate in the inner coating solution is 50 wt%, and the concentration of calcium hydroxide is 2 wt%.

[0081] (2) Place the alumina balls (outer diameter 1 mm) in a disc granulator, and then spray the inner coating liquid onto the surface of the ceramic balls using an airless spraying method. After the spraying is completed, place the sample in a forced-air drying oven and dry it at a drying temperature of 140℃.

[0082] (3) Place the sample in a tube furnace, raise the temperature at a rate of 15℃ / min, raise it to 1000℃, and hold it at the temperature for 18h.

[0083] (4) Dissolve niobium oxalate in water to prepare an outer coating solution with a concentration of 40 wt%;

[0084] (5) The sample obtained in step (3) is placed in the disc granulator again, and then the outer coating liquid is sprayed onto the surface of the ceramic ball by air spraying. After the spraying is completed, the sample is placed in the blower oven and dried at a drying temperature of 140°C to obtain the anti-sulfur poisoning catalyst.

[0085] Application Example 5

[0086] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:1.3 were reacted under the catalysis of the anti-sulfur poisoning catalyst prepared in Example 5 to produce tetrahydrothiophene at a catalytic reaction temperature of 260°C.

[0087] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 99.3%; the deactivation rate was 0.011% / h.

[0088] Comparative Example 2

[0089] A sulfur poisoning resistant catalyst, the preparation method includes the following steps:

[0090] (1) Dissolve potassium aluminum sulfate, cobalt sulfate and barium hydroxide in water to prepare a coating solution. The concentration of potassium aluminum sulfate in the coating solution is 50 wt%, the concentration of zinc hydroxide is 5 wt%, and the concentration of cobalt sulfate is 35 wt%.

[0091] (2) Alumina powder and coating liquid powder with a mass ratio of 1:1 are mixed and granulated in a disc granulator to obtain particles with a particle size of 1 mm. The sample is then placed in a forced-air drying oven and dried at a drying temperature of 140℃.

[0092] (3) The sample was placed in a tube furnace and heated at a rate of 15℃ / min until it reached 1000℃. The temperature was held for 18 hours to obtain the anti-sulfur poisoning catalyst.

[0093] Comparative Application Example 2

[0094] Tetrahydrofuran and hydrogen sulfide in a molar ratio of 1.0:1.3 were reacted with the anti-sulfur poisoning catalyst prepared in Comparative Example 2 to produce tetrahydrothiophene at a catalytic temperature of 260°C.

[0095] The initial tetrahydrothiophene yield of the sulfur poisoning resistant catalyst was 98.1%; the deactivation rate was 0.845% / h.

[0096] Table 3 Catalyst Evaluation Table

[0097]

[0098] As shown in Table 3, the catalyst prepared by the method of this patent exhibits excellent catalytic performance in the direct sulfidation of tetrahydrofuran to synthesize tetrahydrothiophene. The maximum yield of tetrahydrothiophene is 99.5%, and the minimum deactivation rate is 0.01% / h.

[0099] Comparing and analyzing Application Example 4 and Comparative Application Example 1, it is shown that compared with the catalyst prepared by mixing the two coating liquids into one coating liquid and then coating spherical aggregates, the catalyst prepared by coating spherical aggregates one by one with the two coating liquids has better surface active components and physicochemical structural characteristics, resulting in better catalytic performance.

[0100] Comparison and analysis of Application Example 5 and Comparative Application Example 2 show that, compared with the in-situ method for catalyst preparation, the catalysts prepared by coating spherical aggregates one by one with the two coating liquids have better surface active components and physicochemical structural characteristics, resulting in better catalytic performance.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a sulfur poisoning resistant catalyst, characterized in that, Includes the following steps: (1) Dissolve soluble aluminum salt and inorganic binder in solvent I to prepare inner coating liquid, then spray the inner coating liquid onto the surface of spherical aggregate and dry it, and then calcine to activate it; (2) Dissolve the active component in solvent II to prepare an outer coating liquid, spray it onto the surface of the spherical aggregate obtained in step (1), and dry it to obtain an anti-sulfur poisoning catalyst. The inorganic binder is one of aluminum hydroxide, iron hydroxide, copper hydroxide, zinc hydroxide, nickel hydroxide, calcium hydroxide, and barium hydroxide. The spherical aggregate is one of ceramic spheres, silicon dioxide spheres, silicon carbide spheres, and alumina spheres; The active component is a non-precious metal salt, which is one of tin oxalate, niobium oxalate, cobalt oxalate, and cobalt sulfate.

2. The method for preparing the anti-sulfur poisoning catalyst according to claim 1, characterized in that, The soluble aluminum salt is one of sodium aluminate, potassium aluminate, aluminum sulfate, aluminum nitrate, or potassium aluminum sulfate.

3. The method for preparing the anti-sulfur poisoning catalyst according to claim 2, characterized in that, The concentration of soluble aluminum salt in the inner coating solution is 5-50 wt%, and the concentration of inorganic binder is 5-20 wt%.

4. The method for preparing the anti-sulfur poisoning catalyst according to claim 1, characterized in that, The outer diameter of the spherical aggregate is 1-5 mm.

5. The method for preparing the anti-sulfur poisoning catalyst according to claim 4, characterized in that, The spraying method in steps (1) and (2) is as follows: the spherical aggregate is placed in the granulator, and the inner coating liquid and outer coating liquid are coated on the surface of the spherical aggregate by air spraying or airless spraying.

6. The method for preparing the anti-sulfur poisoning catalyst according to claim 1, characterized in that, The concentration of the active component in the coating solution is 5-50 wt%.

7. The method for preparing the anti-sulfur poisoning catalyst according to claim 1, characterized in that, The calcination activation temperature is 700-1200℃, the holding time is 1-24h, and the heating rate is 5-25℃ / min.

8. The sulfur poisoning resistant catalyst prepared by the method according to any one of claims 1-7.

9. The application of the anti-sulfur poisoning catalyst according to claim 8, characterized in that, Tetrahydrothiophene was prepared by using a sulfur-resistant catalyst to catalyze the reactants tetrahydrofuran and hydrogen sulfide.

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