Dry gas hydrogenation catalyst and method of making same

Abstract

This invention discloses a dry gas hydrogenation catalyst and its preparation method. The support component is alumina, and the active components are Group VIB metal sulfides and Group VIII metal sulfides. The average number of lamellar layers of the sulfides is <1.5 layers, and the proportion of single layers is 65%~80%. Based on the weight of the catalyst, Group VIB metal sulfides account for 1wt%~20wt% of the total mass of the catalyst, and Group VIII metal sulfides account for 0.5wt%~10wt% of the total mass of the catalyst. The total acid content of the catalyst is 0.1~0.25 mmol / g, of which the strong acid content at 400-500℃ accounts for 1%~6%, the medium-strength acid content at 250-400℃ accounts for 10%~20%, and the weak acid content at 150-250℃ accounts for 74%~89%. The preparation method is as follows: Boehmite dry adhesive powder is calcined at high temperature in an oxygen-containing atmosphere. The alumina dry adhesive powder is then impregnated with an active component impregnation solution, dried, and calcined at high temperature in an oxygen-containing atmosphere. Finally, it is calcined in a mixed atmosphere of H2S and H2. After molding, drying, and calcination, a dry gas hydrogenation catalyst is obtained. The catalyst of this invention exhibits good hydrogenation performance for organic sulfur and olefins, and also possesses excellent resistance to carbon deposition.

Description

Technical Field

[0001] This invention relates to the field of hydrogenation of low-carbon hydrocarbons, and specifically to a dry gas hydrogenation catalyst and its preparation method. Background Technology

[0002] Light hydrocarbon resources such as catalytic dry gas and coking dry gas in refineries have long been used as fuel gas for refinery self-use, and their economic benefits have not been fully developed. However, by hydrogenating coking dry gas to saturate the dienes and olefins and remove impurities such as sulfur and oxygen, it can be used as a high-quality feedstock for olefin production. Its triene yield is high, which can not only make up for the shortage of ethylene feedstock, but also improve economic efficiency.

[0003] CN200910230393.4 discloses a bifunctional hydrogenation catalyst for use in the hydrorefining process of high-olefin-content feedstocks such as coking dry gas or catalytic dry gas, exhibiting excellent performance in the hydrogenolysis of organic sulfur and olefin saturation. This catalyst utilizes a Co-Mo-Ni-Cu rare earth element active metal supported on titanium oxide-alumina, which can effectively hydrogenate organic sulfur and olefins in coking dry gas and catalytic dry gas.

[0004] CN201911052623.2 discloses a dry gas hydrodesulfurization catalyst, its preparation method, and its application. The catalyst comprises raspberry-shaped particles composed of an active component a, a structural aid b, and other aids c. The raspberry-shaped particles are hollow microspheres with a large pore on their surface. The hollow microspheres have a hollow structure inside, with the large pore communicating with the hollow structure to form a cavity open at one end. The active component a is selected from Ni and Mo as its metal element. The structural aid b is selected from one or more of alumina, silicon dioxide, titanium dioxide, and zirconium oxide. The other aid c is selected from one or more of Cu, La, Ce, W, Mn, and Zn as its metal element.

[0005] CN201911053316.6 discloses a dry gas hydrogenation catalyst for saturated olefins and desulfurization, its preparation method, and its application. The catalyst comprises a support and an active metal component supported on the support, wherein the active metal component comprises molybdenum and a Group VIII metal, with the molybdenum content (based on oxides and the catalyst itself) being 10-45 wt%; the Group VIII metal content being 1-10 wt%; and the support oxide content being 50-89 wt%, preferably 55-80 wt%.

[0006] Numerous studies and experiments have shown that during the hydrogenation of olefins, dry gas hydrogenation catalysts gradually generate carbon deposits, leading to a decrease in their activity. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention discloses a dry gas hydrogenation catalyst and its preparation method. This catalyst exhibits good hydrogenation performance for organic sulfur and olefins, as well as excellent resistance to carbon deposition.

[0008] The dry gas hydrogenation catalyst of the present invention comprises a support component and an active component. The support component is alumina, and the active component is a Group VIB metal sulfide and a Group VIII metal sulfide. The average number of lamellar layers of the sulfides is <1.5 layers, and the proportion of single layers is 65%~80%. Based on the weight of the catalyst, the Group VIB metal sulfide accounts for 1wt%~20wt% of the total mass of the catalyst, and the Group VIII metal sulfide accounts for 0.5wt%~10wt% of the total mass of the catalyst. The total acid content of the catalyst is 0.1~0.25 mmol / g, of which the strong acid content at 400-500℃ accounts for 1%~6%, the medium-strength acid content at 250-400℃ accounts for 10%~20%, and the weak acid content at 150-250℃ accounts for 74%~89%. The Group VIB metal is preferably Mo and / or W, and the Group VIII metal is preferably Co and / or Ni.

[0009] The preparation method of the dry gas hydrogenation catalyst of the present invention includes the following:

[0010] (1) Take boehmite dry adhesive powder A and calcine it at high temperature in an oxygen-containing atmosphere to obtain alumina dry adhesive powder B;

[0011] (2) Alumina dry adhesive powder B was impregnated with group VIB and group VIII active component impregnation solution C, dried, calcined at high temperature in an oxygen-containing atmosphere, and then calcined in a mixed atmosphere of H2S and H2 to obtain powder D;

[0012] (3) The powder D prepared in step (2) is shaped, dried and calcined to obtain a dry gas hydrogenation catalyst.

[0013] In the method of the present invention, the pseudo-boehmite dry adhesive powder A mentioned in step (1) is a commonly used commodity on the market, which can be prepared by methods such as aluminum alkoxide method, sodium aluminate neutralization method, and carbonization method.

[0014] In the method of the present invention, the oxygen content in the oxygen-containing atmosphere in step (1) is 10v%~30v%, preferably an air atmosphere, and the high-temperature calcination conditions are: calcination temperature of 800~1100℃ and calcination time of 0.5~5 hours.

[0015] In the method of the present invention, the oxygen content in the oxygen-containing atmosphere in step (2) is 10v%~30v%, preferably an air atmosphere, and the high-temperature calcination conditions are: calcination temperature of 800~1100℃ and calcination time of 0.5~5 hours.

[0016] In the method of the present invention, the calcination conditions of the H2S and H2 mixed atmosphere in step (2) are: calcination temperature of 250~550℃ and calcination time of 3~8 hours; wherein the proportion of H2S in the H2S and H2 mixed atmosphere is 0.1v%~2v.

[0017] In the method of this invention, the impregnation solution C for the active components of Group VIB and Group VIII mentioned in step (2) is an aqueous solution prepared by conventional methods. For example, the impregnation solution C can be an aqueous solution prepared from salts such as ammonium molybdate, ammonium metatungstate, cobalt nitrate, nickel nitrate, basic cobalt carbonate, and basic nickel carbonate. The selected metal salts are all water-soluble, but are not limited to the above-mentioned salts. The amount of each component added to the impregnation solution is calculated based on the content of each component on the catalyst.

[0018] In the method of the present invention, the impregnation method in step (2) is saturated impregnation or supersaturated impregnation, which is well known to those skilled in the art; the drying process is also well known to those skilled in the art, such as conventional drying or vacuum drying.

[0019] In the method of this invention, the catalyst forming process described in step (3) is a method well known in the art, such as adding an extrusion aid to the powder, mixing the adhesive and water to form a plastic body, and then kneading and shaping it. The extrusion aid is one or more of methylcellulose, guar gum powder, starch, and polyvinyl alcohol. The adhesive is one or more of dilute nitric acid, dilute phosphoric acid, and silicic acid.

[0020] In the method of the present invention, the drying conditions described in steps (2) and (3) are: drying time of 1 to 5 hours and drying temperature of 80 to 120°C.

[0021] In the method of this invention, the calcination conditions in step (3) are: calcination temperature of 200~350℃ and calcination time of 1~4 hours. The calcination atmosphere is an inert atmosphere, selected from one or more gases selected from N2, He or Ar.

[0022] The dry gas hydrogenation catalyst of the present invention is applied to the reaction of dry gas hydrogenation to produce low-carbon hydrocarbons, under the following reaction conditions: reaction pressure 0.1~10 MPa, gas hourly space velocity 300~10000 h⁻¹. -1 The reaction temperature is 150~400℃. Specific process conditions can be adjusted according to the differences in raw material quality.

[0023] The inventors discovered that organic sulfur in dry gas is mostly carbonyl sulfide, and single-layer metal sulfides are sufficient to meet desulfurization activity requirements. While multilayer metal sulfides exhibit high desulfurization activity, during dry gas hydrogenation, the rapid saturation of olefins and the resulting exothermic reaction lead to the migration and aggregation of these multilayer sulfides. Furthermore, the presence of strong acidity on the catalyst surface and impurities such as oxygen further promotes olefin polymerization and carbon deposition. These factors reduce the catalyst's desulfurization and olefin saturation activity. High-temperature treatment significantly reduces the acidity of alumina dry powder. Impregnation with Group VIB and / or Group VIII active metals followed by high-temperature calcination results in metal sulfides that are primarily single-layered with stronger interactions with the support, significantly improving the catalyst's activity stability. Attached Figure Description

[0024] Figure 1 The image shows the X-ray photoelectron (XPS) spectrum of the catalyst in Example 1. Detailed Implementation

[0025] The following examples further illustrate the solution and effects of the present invention, but do not constitute a limitation on the present invention.

[0026] In this invention, a commercially available boehmite dry adhesive powder purchased from Sinopec Catalyst Dalian Branch was selected. This boehmite dry adhesive powder has a specific surface area of ​​392 m². 2 / g, pore volume 0.95 cm³ 3 / g, pore size 9.7nm, dry basis 70%. The valence states of each active metal on the catalyst were characterized by XPS energy dispersive spectroscopy. The acidity of the catalyst was determined by the NH3-TPD method. The number of lamellar layers of sulfides on the catalyst was obtained by statistical analysis using TEM images. The components of the raw materials and products were obtained by normalization calculations based on chromatographic analysis.

[0027] Example 1

[0028] A certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 950℃ for 1.5h in air to obtain alumina dry adhesive powder B. Then, 12.8g of ammonium heptamolybdate and 13.0g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 100mL of active component aqueous solution C. 100g of the calcined alumina dry adhesive powder B was impregnated with the loading solution C, dried at 100℃ for 3h, calcined at 1050℃ in air for 1.5h, and then treated at 400℃ in a mixed atmosphere of 1% H2S and H2 for 6h to obtain powder D. Powder D was pulverized and sieved (200 mesh), and then 2.5g of guar gum powder, 20g of 10% nitric acid and 100mL of deionized water were added. After molding, it was dried at 100℃ for 3h and then calcined at 350℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-1. According to the NISTXPS database, as shown... Figure 1 The metals shown are Mo with a +4 oxidation state (MoS2) and Co with a +2 oxidation state (CoS).

[0029] Example 2

[0030] A certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 1000℃ for 1.5h in air to obtain alumina dry adhesive powder B. Then, 10.4g of ammonium heptamolybdate and 17.3g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 100mL of active component aqueous solution C. 120g of the calcined alumina dry adhesive powder B was impregnated with the loading solution C, dried at 110℃ for 3h, calcined at 900℃ in air for 2h, and then treated at 450℃ in a mixed atmosphere of 1% H2S and H2 for 6h to obtain powder D. Powder D was pulverized and sieved (200 mesh), and then 2g of guar gum powder, 20g of 10% nitric acid and 120mL of deionized water were added. After molding, it was dried at 110℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-2.

[0031] Example 3

[0032] A certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 1050℃ for 1 hour in air to obtain alumina dry adhesive powder B. Then, 14.9g of ammonium metatungstate and 11.5g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 100mL of active component aqueous solution C. 100g of the calcined alumina dry adhesive powder B was impregnated with the loading solution C, dried at 110℃ for 2 hours, calcined at 850℃ in air for 2 hours, and then treated at 350℃ in a mixed atmosphere of 1% H2S and H2 for 6 hours to obtain powder D. Powder D was pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 110mL of deionized water were added. After molding, it was dried at 110℃ for 2 hours and then calcined at 250℃ in a nitrogen atmosphere for 2 hours to obtain the final catalyst C-3.

[0033] Example 4

[0034] A certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 900℃ for 3 hours in air to obtain alumina dry adhesive powder B. Then, 7.7g of ammonium metatungstate, 5.1g of ammonium heptamolybdate, and 7.4g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 100mL aqueous solution C of the active component. 100g of the calcined alumina dry adhesive powder B was impregnated with the loading solution C, dried at 90℃ for 4 hours, calcined at 1000℃ in air for 2 hours, and then treated at 300℃ in a mixed atmosphere of 1% H2S and H2 for 6 hours to obtain powder D. Powder D was pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid, and 100mL of deionized water were added. After molding, it was dried at 90℃ for 4 hours and then calcined at 300℃ in a nitrogen atmosphere for 2 hours to obtain the final catalyst C-4.

[0035] Comparative Example 1

[0036] The preparation method of Example 1 was followed, but the boehmite powder was not subjected to high-temperature calcination during the preparation process. 12.8 g of ammonium heptamolybdate and 13.0 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 100 mL aqueous solution C of the active component. 139 g of boehmite dry adhesive powder A was impregnated with the loading solution C, dried at 100°C for 3 h, calcined at 1050°C in air for 1.5 h, and then treated at 400°C in a mixed atmosphere of 1% H2S and H2 for 6 h to obtain powder D. Powder D was pulverized and sieved (200 mesh), and then 2.5 g of guar gum powder, 20 g of 10% nitric acid, and 100 mL of deionized water were added. After molding, it was dried at 100°C for 3 h, and then calcined at 350°C in a nitrogen atmosphere for 2 h to obtain the final catalyst D-1.

[0037] Comparative Example 2

[0038] The preparation method of Example 1 was followed, but the high-temperature calcination in step (1) was omitted, and instead, the pseudoboehmite powder was calcined at low temperature to obtain γ-alumina. A certain amount of the above pseudoboehmite dry adhesive powder A was calcined at 550°C for 3 hours in air to obtain γ-alumina powder. Then, 12.8 g of ammonium heptamolybdate and 13.0 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 100 mL of active component aqueous solution C. 100 g of calcined γ-alumina powder was impregnated with the loading solution C, dried at 100°C for 3 hours, calcined at 1050°C in air for 1.5 hours, and then treated at 400°C in a mixed atmosphere of 1% H2S and H2 for 6 hours to obtain powder D. After pulverizing powder D and sieving it (200 mesh), 2.5g of guar gum powder, 20g of 10% nitric acid and 100mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 350℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-2.

[0039] Comparative Example 3

[0040] The preparation method of Example 1 was followed, but the powder impregnated with Group VIB and Group VIII metals was not subjected to high-temperature calcination during the preparation process. A certain amount of the above-mentioned pseudoboehmite dry adhesive powder A was calcined at 950°C for 1.5 h in air to obtain alumina dry adhesive powder B. Then, 12.8 g of ammonium heptamolybdate and 13.0 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 100 mL of active component aqueous solution C. 100 g of calcined alumina dry adhesive powder B was impregnated with the loading solution C, dried at 100°C for 3 h, and then treated at 400°C in a mixed atmosphere of 1% H2S and H2 for 6 h to obtain powder D. After pulverizing powder D and sieving it (200 mesh), 2.5g of guar gum powder, 20g of 10% nitric acid and 100mL of deionized water were added. After molding, the powder was dried at 100℃ for 3h and then calcined at 350℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-3.

[0041] The component content and properties of each catalyst are listed in Table 1.

[0042] Table 1. Catalyst component content and properties in the examples and comparative examples

[0043]

[0044] The above catalyst was subjected to an activity evaluation test in a 10 mL reaction apparatus, with a reaction pressure of 5 MPa, a reaction temperature of 200 °C, and a gas hourly space velocity of 1100 h⁻¹. -1 The properties of the raw materials are shown in Table 2, the evaluation results after 1000 h of reaction are shown in Table 3, and the amount of carbon deposited on the catalyst is shown in Table 4.

[0045] Table 2 Composition of Coking Dry Gas Feedstock

[0046]

[0047] Table 3 Composition of the product after hydrogenation after 1000 h of reaction

[0048]

[0049] Table 4. Carbon deposits on the catalyst after hydrogenation

[0050]

[0051] The evaluation results in Table 3 and the amount of carbon deposit on the catalyst after hydrogenation in Table 4 demonstrate that the catalyst activity of the present invention meets the requirements for olefin saturation and removal of impurities such as sulfur and oxygen. Furthermore, the amount of carbon deposit is low even after 1000 hours of reaction, indicating that the catalyst has better stability.

Claims

1. A dry gas hydrogenation catalyst, characterized in that: The catalyst comprises a support component and an active component. The support component is alumina, and the active component consists of Group VIB and Group VIII metal sulfides. The average number of lamellar layers of the sulfides is <1.5 layers, with a single layer ratio of 65%–73%. Based on the weight of the catalyst, Group VIB metal sulfides account for 10 wt%–20 wt% of the total catalyst mass, and Group VIII metal sulfides account for 0.5 wt%–3.5 wt% of the total catalyst mass. The total acid content of the catalyst is 0.1~0.25 mmol / g, of which strong acid at 400~500℃ accounts for 1%~6%, medium-strength acid at 250~400℃ accounts for 10%~20%, and weak acid at 150~250℃ accounts for 74%~89%. The dry gas hydrogenation catalyst is prepared by the following method: 1) taking boehmite dry adhesive powder A and calcining it at high temperature in an oxygen-containing atmosphere to obtain alumina dry adhesive powder B; 2) impregnating alumina dry adhesive powder B with active component impregnation solution C, drying it, calcining it at high temperature in an oxygen-containing atmosphere, and then calcining it in a mixed atmosphere of H2S and H2 to obtain powder D; 3) molding, drying and calcining the powder D prepared in step 2) to obtain the dry gas hydrogenation catalyst.

2. A method for preparing the dry gas hydrogenation catalyst according to claim 1, characterized in that... The following are included: (1) Take boehmite dry adhesive powder A and calcine it at high temperature in an oxygen-containing atmosphere to obtain alumina dry adhesive powder B; (2) Impregnate alumina dry adhesive powder B with active component impregnation liquid C, dry it, calcine it at high temperature in an oxygen-containing atmosphere, and then calcine it in a mixed atmosphere of H2S and H2 to obtain powder D; (3) Take the powder D prepared in step (2), shape it, dry it, and calcine it to obtain a dry gas hydrogenation catalyst.

3. The method according to claim 2, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (1) is 10v%~30v.

4. The method according to claim 3, characterized in that: Step (1) uses an air atmosphere. The high-temperature calcination conditions are: calcination temperature of 800~1100℃ and calcination time of 0.5~5 hours.

5. The method according to claim 2, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (2) is 10v%~30v.

6. The method according to claim 5, characterized in that: Step (2) uses an air atmosphere. The high-temperature calcination conditions are: calcination temperature of 800~1100℃ and calcination time of 0.5~5 hours.

7. The method according to claim 2, characterized in that: The calcination conditions for the H2S and H2 mixed atmosphere in step (2) are: calcination temperature of 250~550℃ and calcination time of 3~8 hours; wherein the proportion of H2S in the H2S and H2 mixed atmosphere is 0.1v%~2v.

8. The method according to claim 2, characterized in that: The catalyst forming process described in step (3) involves adding an extrusion aid, a binder, and water to the powder to form a plastic body, which is then kneaded and shaped. The extrusion aid is one or more of methylcellulose, guar gum powder, starch, and polyvinyl alcohol; the adhesive solvent is one or more of dilute nitric acid, dilute phosphoric acid, and silicic acid.

9. The method according to claim 2, characterized in that: The drying conditions described in steps (2) and (3) are: drying time of 1 to 5 hours and drying temperature of 80 to 120°C.

10. The method according to claim 2, characterized in that: The roasting conditions described in step (3) are: roasting temperature of 200~350℃, roasting time of 1~4 hours; and roasting atmosphere of inert atmosphere, selected from one or more gases of N2, He or Ar.

11. The application of the dry gas hydrogenation catalyst according to claim 1 in the reaction of dry gas hydrogenation to produce low-carbon hydrocarbons, wherein the reaction conditions are: reaction pressure 0.1~10MPa, gas hourly space velocity 300-10000h⁻¹ -1 The reaction temperature is 150~400℃.

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