A method for preparing a dry gas hydrogenation low-carbon hydrocarbon catalyst

Abstract

This invention discloses a method for preparing a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons, comprising the following steps: (1) taking boehmite dry gel powder A and calcining it at high temperature in an oxygen-containing atmosphere to obtain alumina dry gel powder B; (2) impregnating alumina dry gel powder B with an active component impregnation solution C containing quaternary ammonium salt compounds, 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 E; (3) impregnating boehmite dry gel powder A with an active auxiliary impregnation solution D, drying it, and calcining it in a hydrogen atmosphere to obtain powder F; (4) mixing powder E and powder F evenly, and then molding, drying, and calcining to obtain a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons. The catalyst prepared by the method of this invention has excellent olefin saturation activity and can saturate olefins with hydrogenation at a relatively low temperature. At the same time, the catalyst of this invention also has good activity in removing impurities such as oxygen, sulfur, CO, and CO2.

Description

Technical Field

[0001] This invention relates to the field of hydrogenation of dry gas to produce low-carbon hydrocarbons, and specifically to a method for preparing hydrogenation catalysts for dry gas with high olefin content. Background Technology

[0002] After hydrogenation, dry gas can serve as a high-quality feedstock for ethylene cracking, supplementing the shortage of feedstock in refineries. However, when the catalyst's olefin hydrogenation saturation capacity is insufficient, it cannot meet the olefin content requirements of downstream units. Furthermore, impurities such as oxygen, sulfur, CO, and CO2 in the dry gas are poisons for downstream units, such as hydrogen production units, and also require hydrogenation for removal.

[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] Reaction mechanism studies show that long-chain olefins are more difficult to remove than short-chain olefins. If the reaction temperature is simply increased, the degree of hydrogenation saturation of olefins will not increase due to the influence of the thermodynamic equilibrium of the olefin hydrogenation reaction. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes a method for preparing a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons. The catalyst prepared by this method exhibits excellent olefin saturation activity, enabling olefin hydrogenation saturation at relatively low temperatures. Furthermore, the catalyst also demonstrates good activity in removing impurities such as oxygen, sulfur, CO, and CO2.

[0008] The preparation method of the catalyst for dry gas hydrogenation to produce low-carbon hydrocarbons of the present invention includes the following:

[0009] (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;

[0010] (2) Alumina dry adhesive powder B is impregnated with active component impregnation solution C containing quaternary ammonium salt compounds, dried, calcined at high temperature in an oxygen-containing atmosphere, and then calcined in a mixed atmosphere of H2S and H2 to obtain powder E.

[0011] (3) Impregnate pseudoboehmite dry adhesive powder A with active additive impregnation solution D, dry, and calcine in hydrogen atmosphere to obtain powder F;

[0012] (4) After mixing the powder E prepared in step (2) with the powder F prepared in step (3) evenly, the powder is shaped, dried and calcined to obtain a catalyst for the production of low-carbon hydrocarbons by hydrogenation of dry gas.

[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 active component in step (2) is a Group VIB and Group VIII metal, wherein the Group VIB metal is preferably Mo and / or W; the Group VIII metal is preferably Co and / or Ni; the active component impregnation solution C is an aqueous solution of the Group VIB and Group VIII metals, wherein a quaternary ammonium salt compound is added to adjust the pH of the impregnation solution to 7.5-11.5; for example, the active component impregnation solution C is an aqueous solution prepared from salts such as ammonium molybdate, ammonium metatungstate, cobalt nitrate, nickel nitrate, basic cobalt carbonate, and basic nickel carbonate; wherein the quaternary ammonium salt compound has 4-19 carbon atoms, preferably one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, dodecyltrimethylammonium hydroxide, and hexadecyltrimethylammonium hydroxide. The amount of each component added to the impregnation solution is calculated according to the content of each component on the catalyst.

[0018] In the method of the present invention, the calcination conditions in the hydrogen atmosphere described in step (3) are: calcination temperature of 300~700℃ and calcination time of 2~5 hours.

[0019] In the method of this invention, the active agent in step (3) is one or more of Cu, Ag, Ni, Co, W, and Mo; the active agent impregnation solution D in step (3) is an aqueous solution prepared by conventional methods. For example, the active agent D can be an aqueous solution prepared from salts such as copper nitrate, silver nitrate, 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 in the impregnation solution is calculated based on the content of each component on the catalyst.

[0020] In the method of the present invention, the impregnation method described in steps (2) and (3) is saturated impregnation or supersaturated impregnation, which is well known to those skilled in the art; the drying process described is also well known to those skilled in the art, such as conventional drying or vacuum drying.

[0021] In the method of this invention, the catalyst forming process described in step (4) is a method well known in the art, such as adding an extrusion aid to the composite powder, mixing the adhesive solvent and water to form a plastic body, and then kneading and forming it. 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.

[0022] In the method of the present invention, the drying conditions described in steps (2), (3) and (4) are: drying time of 1 to 5 hours and drying temperature of 80 to 120°C.

[0023] In the method of this invention, the calcination conditions in step (4) 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.

[0024] The dry gas hydrogenation catalyst for producing low-carbon hydrocarbons prepared by the method of this invention comprises a support component, an active component, and an active promoter; the support component is alumina; the active component is a Group VIB metal sulfide and a Group VIII metal sulfide, wherein the average number of lamellar layers of the sulfide is <1.5 layers, and the proportion of monolayers is 70-85%; wherein the Group VIB metal is preferably Mo and / or W; the Group VIII metal is preferably Co and / or Ni; the active promoter exists in a metallic form and is selected from one or more of Cu, Ag, Ni, Co, W, and Mo; the catalyst is based on the weight of the catalyst. The catalyst contains 1 wt% to 20 wt% of Group VIB metal sulfides and 0.5 wt% to 10 wt% of Group VIII metal sulfides. The catalyst contains 0.1 wt% to 4 wt% of active promoters, preferably 0.3 wt% to 4 wt%. The total acid content of the catalyst is 0.1 to 0.4 mmol / g, of which 5 to 15% is strong acid at 400-500℃, 10 to 20% is moderately strong acid at 250-400℃, and 65% to 85% is weak acid at 150-250℃.

[0025] The application of the dry gas hydrogenation catalyst of the present invention in the dry gas hydrogenation reaction 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℃. Specific process conditions can be adjusted according to the differences in raw material quality.

[0026] The inventors discovered that when the interaction between the support and Group VIB and / or Group VIII active metals is weak, the metal sulfides formed after sulfidation have a multilayered structure. During the hydrogenation of coking dry gas, the rapid saturation of olefins and the resulting exothermic reaction lead to the migration and aggregation of these multilayered sulfides. Simultaneously, the strong acidity of the catalyst surface and the presence of impurities such as oxygen, CO, and CO2 can cause olefin polymerization and carbon deposition. These factors reduce the catalyst's desulfurization and olefin saturation activity. High-temperature treatment significantly reduces the acidity of the alumina dry powder. Impregnation with Group VIB and / or Group VIII active metals followed by high-temperature calcination strengthens the interaction between alumina and the metal, reduces the formation of multilayered metal sulfides after sulfidation, and improves the stability of the catalyst's desulfurization and olefin saturation activity. Adding quaternary ammonium salts to the impregnation solutions of Group VIB and Group VIII active metals and adjusting the pH to alkaline can dissociate the polymolybdate ions in the impregnation solution into monomolybdate ions and disperse them well. The metal sulfides generated after sulfidation have a monolayer structure, and more Group VIII metal active sites with hydrogen activation capabilities are formed, thus improving the olefin hydrogenation saturation performance of the catalyst under low-temperature conditions.

[0027] Furthermore, if the dry gas contains excessive amounts of impurities such as oxygen, CO, and CO2, especially CO, it will adsorb onto the active metal, reducing the catalyst's hydrogenation and desulfurization performance. The inventors utilize an active additive that has the advantage of adsorbing and removing impurities such as oxygen, CO, and CO2 through a hydrogenation reaction. Simultaneously, the untreated boehmite powder has better colloidal solubility compared to high-temperature calcined alumina powder, allowing for direct molding into a catalyst. Moreover, the catalyst contains more weak acids and fewer strong acids, resulting in a weaker interaction between the active additive and the boehmite powder. This facilitates the low-temperature reduction and dispersion of the active additive, thereby improving its performance in hydrogenating and removing impurities such as oxygen, CO, and CO2. Attached Figure Description

[0028] Figure 1 The image shows the X-ray photoelectron (XPS) spectrum of the catalyst in Example 1. Detailed Implementation

[0029] The following examples further illustrate the solution and effects of the present invention, but do not constitute a limitation on the present invention.

[0030] 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.

[0031] Example 1

[0032] 18.2g of ammonium heptamolybdate, 39.6g of cobalt nitrate hexahydrate, and 18g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare a 140mL aqueous solution C of the active component. The pH of solution C was 11.0. Similarly, 12.2g of copper nitrate and 16.4g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90mL aqueous solution D of the auxiliary component. Then, a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A was calcined at 1000℃ for 1.5h in air to obtain alumina dry adhesive powder B. 100g of the calcined alumina dry adhesive powder B was impregnated with the active component aqueous solution C, dried at 100℃ for 3h, calcined at 1000℃ in air for 1.5h, and then treated at 400℃ in a mixed atmosphere of 1% H2S and H2 for 6h to obtain powder E. 100g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the supported additive component D, dried at 100℃ for 3h, and then calcined at 650℃ in a hydrogen atmosphere for 4h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-1. (Based on a search of the NIST XPS database, such as...) Figure 1 The metals shown are Mo in the +4 valence state (MoS2), Co in the +2 valence state (CoS), and Cu and Ni in the 0 valence state (metallic state).

[0033] Example 2

[0034] Take 14.0g ammonium metatungstate, 4.0g ammonium heptamolybdate, 40.8g nickel nitrate hexahydrate, and 8g tetrapropylammonium hydroxide, dissolve them in an appropriate amount of water to prepare a 140mL aqueous solution C of the active component. The pH of solution C is 8.0. Similarly, take 4.5g cobalt nitrate hexahydrate and 4.5g nickel nitrate hexahydrate, dissolve them in an appropriate amount of water to prepare a 50mL aqueous solution D of the auxiliary component. Then, take a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A and calcine it at 800℃ for 5h in an air atmosphere to obtain alumina dry adhesive powder B. Impregnate 100g of the calcined alumina dry adhesive powder B with the active component aqueous solution C, dry it at 110℃ for 3h, calcine it at 900℃ in an air atmosphere for 4h, and then treat it at 500℃ in a mixed atmosphere of 1% H2S and H2 for 4h to obtain powder E. 70g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 110℃ for 3h, and then calcined at 550℃ in a hydrogen atmosphere for 2h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 13g of 10% nitric acid and 170mL of deionized water were added. After molding, the mixture was dried at 110℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-2.

[0035] Example 3

[0036] 18.4g of ammonium heptamolybdate, 33.4g of nickel nitrate hexahydrate, and 14g of tetraethylammonium hydroxide were dissolved in an appropriate amount of water to prepare a 120mL aqueous solution C of the active component. The pH of solution C was 9.5. Similarly, 6.6g of silver nitrate and 1.6g of ammonium metatungstate were dissolved in an appropriate amount of water to prepare a 56mL aqueous solution D of the auxiliary component. Then, a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A was calcined at 950℃ for 3 hours in air to obtain alumina dry adhesive powder B. 120g of the calcined alumina dry adhesive powder B was impregnated with the active component aqueous solution C, dried at 110℃ for 2 hours, calcined at 1000℃ in air for 1 hour, and then treated at 350℃ in a mixed atmosphere of 1% H2S and H2 for 5 hours to obtain powder E. 80g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 110℃ for 2h, and then calcined at 450℃ in a hydrogen atmosphere for 3h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 16g of 10% nitric acid and 160mL of deionized water were added. After molding, the mixture was dried at 110℃ for 2h and then calcined at 250℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-3.

[0037] Example 4

[0038] Take 19.5g of ammonium metatungstate, 4.5g of ammonium heptamolybdate, 13.0g of nickel nitrate hexahydrate, and 10g of dodecyltrimethylammonium hydroxide, and dissolve them in an appropriate amount of water to prepare a 100mL aqueous solution C of the active component. The pH of solution C is 9.0. Similarly, take 11.9g of copper nitrate, dissolve it in an appropriate amount of water, and prepare a 70mL aqueous solution D of the auxiliary component. Then, take a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A and calcine it at 900℃ for 5h in an air atmosphere to obtain alumina dry adhesive powder B. Impregnate 100g of the calcined alumina dry adhesive powder B with the active component aqueous solution C, dry it at 90℃ for 4h, calcine it at 850℃ in an air atmosphere for 4h, and then treat it at 300℃ in a mixed atmosphere of 1% H2S and H2 for 7h to obtain powder E. 100g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 90℃ for 4h, and then calcined at 600℃ in a hydrogen atmosphere for 3h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 15g of 10% nitric acid and 160mL of deionized water were added. After molding, the mixture was dried at 90℃ for 4h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-4.

[0039] Comparative Example 1

[0040] The preparation method of Example 1 was followed, but without the addition of any auxiliary components. 18.2 g of ammonium heptamolybdate, 39.6 g of cobalt nitrate hexahydrate, and 18 g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare 140 mL of an aqueous solution C containing the active component. The pH of solution C was 11.0. Then, a certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 1000°C for 1.5 h in air to obtain alumina dry adhesive powder B. 100 g of the calcined alumina dry adhesive powder B was impregnated with the aqueous solution C containing the active component, dried at 100°C for 3 h, calcined at 1000°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 E. Powder E and 80g of pseudoboehmite dry adhesive powder A were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-1.

[0041] Comparative Example 2

[0042] The preparation method of Example 1 was followed, but without adding quaternary ammonium compounds to adjust the pH of the impregnation solution. 18.2 g of ammonium heptamolybdate and 39.6 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 140 mL aqueous solution C of the active component. Similarly, 12.2 g of copper nitrate and 16.4 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90 mL aqueous solution D of the auxiliary component. Then, a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A was calcined at 1000°C for 1.5 h in air to obtain alumina dry adhesive powder B. 100 g of the calcined alumina dry adhesive powder B was impregnated with the active component aqueous solution C, dried at 100°C for 3 h, calcined at 1000°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 E. 100g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 100℃ for 3h, and then calcined at 650℃ in a hydrogen atmosphere for 4h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-2.

[0043] Comparative Example 3

[0044] The preparation method of Example 1 was followed, but the alumina support was not subjected to high-temperature calcination during the preparation process. 18.2 g of ammonium heptamolybdate, 39.6 g of cobalt nitrate hexahydrate, and 18 g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare a 140 mL aqueous solution C of the active component. The pH of solution C was 11.0. Similarly, 12.2 g of copper nitrate and 16.4 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90 mL aqueous solution D of the auxiliary component. Then, 100 g of boehmite dry adhesive powder A was impregnated with the aqueous solution C of the active component, dried at 100°C for 3 h, calcined at 1000°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 E. 100g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 100℃ for 3h, and then calcined at 650℃ in a hydrogen atmosphere for 4h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-3.

[0045] Comparative Example 4

[0046] 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 form γ-alumina. 18.2 g of ammonium heptamolybdate, 39.6 g of cobalt nitrate hexahydrate, and 18 g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare a 140 mL aqueous solution C of the active component. The pH of solution C was 11.0. Similarly, 12.2 g of copper nitrate and 16.4 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90 mL aqueous solution D of the auxiliary component. Then, a certain amount of boehmite dry adhesive powder A was calcined at 550℃ for 3 hours in air to obtain γ-alumina dry adhesive powder. 100g of γ-alumina dry adhesive powder was then impregnated with an aqueous solution C containing the active component, dried at 100℃ for 3 hours, calcined at 1000℃ in air for 1.5 hours, and then treated at 400℃ in a mixed atmosphere of 1% H2S and H2 for 6 hours to obtain powder E. 100g of boehmite dry adhesive powder A was then impregnated with an aqueous solution D containing the auxiliary agent component, dried at 100℃ for 3 hours, and calcined at 650℃ in a hydrogen atmosphere for 4 hours to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-4.

[0047] Comparative Example 5

[0048] The preparation method of Example 1 was followed, but the powder impregnated with Group VIB and / or Group VIII metals was not subjected to high-temperature calcination during the preparation process. 18.2 g of ammonium heptamolybdate, 39.6 g of cobalt nitrate hexahydrate, and 18 g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare a 140 mL aqueous solution C of the active component, with a pH of 11.0. Similarly, 12.2 g of copper nitrate and 16.4 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90 mL aqueous solution D of the auxiliary component. Then, a certain amount of the above-mentioned pseudoboehmite dry adhesive powder A was calcined at 1000°C for 1.5 h in air to obtain alumina dry adhesive powder B. 100 g of the calcined alumina dry adhesive powder B was impregnated with the loaded active component aqueous 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 E. 100g of pseudoboehmite dry adhesive powder A was impregnated with an aqueous solution of the loading additive component D, dried at 100℃ for 3h, and then calcined at 650℃ in a hydrogen atmosphere for 4h to obtain powder F. Powder E and powder F were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 17g of 10% nitric acid and 180mL of deionized water were added. After molding, the mixture was dried at 100℃ for 3h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-5.

[0049] Comparative Example 6

[0050] The preparation method of Example 1 was followed, but the carrier was prepared first, followed by stepwise impregnation of the active metal component and auxiliary component. A certain amount of the above-mentioned boehmite dry adhesive powder A was calcined at 1000°C for 1.5 h in air to obtain alumina dry adhesive powder B. Then, 100 g of calcined alumina dry adhesive powder B was mixed evenly with 100 g of boehmite dry adhesive powder A, pulverized and sieved (200 mesh), and then 2 g of guar gum powder, 17 g of 10% nitric acid and 180 mL of deionized water were added. After molding, it was dried at 100°C for 3 h, and then calcined at 300°C in air for 2 h to obtain the catalyst carrier. 18.2 g of ammonium heptamolybdate, 39.6 g of cobalt nitrate hexahydrate, and 18 g of tetramethylammonium hydroxide were dissolved in an appropriate amount of water to prepare 140 mL of active component aqueous solution C. At this time, the pH value of solution C was 11.0. Similarly, 12.2 g of copper nitrate and 16.4 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 90 mL aqueous solution of the auxiliary component D. The prepared support was impregnated with the loading solution C, dried at 100 °C for 3 h, calcined at 1000 °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 a first-stage catalyst. The first-stage catalyst was loaded with the aqueous solution of the auxiliary component D, dried, and then calcined at 350 °C in a nitrogen atmosphere for 3 h to obtain the finished catalyst D-6.

[0051] The component content and properties of each catalyst are listed in Table 1.

[0052] Table 1. Catalyst component content and properties in the examples and comparative examples

[0053] C-1 C-2 C-3 C-4 D-1 D-2 D-3 D-4 D-5 D-6 Group VIB sulfides, wt% 8.0 10.0 8.0 12.0 8.2 8.0 8.0 8.0 8.0 8.0 Group VIII sulfides, wt% 6.0 7.0 5.0 2.0 5.1 5.0 5.0 5.0 5.0 5.0 Active ingredient c, wt% 3.5 1.0 2.5 2.0 0 2.5 2.5 2.5 2.5 2.5 Total acid content, mmol / g 0.28 0.17 0.35 0.23 0.33 0.42 0.47 0.45 0.32 0.08 Strong acid content at 400-500℃, % 10.5 13.3 8.8 11.2 9.8 10.5 14.7 12.6 11.6 9.6 Medium strength acidity at 250-400℃, % 18.6 11.7 15.8 13.9 15.7 16.6 30.6 35.8 27.4 16.2 Average number of lamellar layers of sulfides 1.2 1.3 1.2 1.2 1.2 1.6 1.4 1.6 1.7 1.5 Sulfide monolayer percentage, % 81 74 84 80 82 51 60 50 46 54

[0054] The above catalyst was subjected to an activity evaluation test in a 10 mL reaction apparatus at a reaction pressure of 2.0 MPa, a reaction temperature of 220 °C, and a gas hourly space velocity of 1000 h⁻¹. -1 The properties of the raw materials are shown in Table 2, the evaluation results after 500 hours of reaction are shown in Table 3, and the amount of carbon deposited on the catalyst is shown in Table 4.

[0055] Table 2 Composition of Coking Dry Gas Feedstock

[0056] composition Content, mol% <![CDATA[H2]]> 12.021 <![CDATA[O2]]> 0.164 <![CDATA[N2]]> 0.026 CO 0.113 <![CDATA[CO2]]> 0.545 <![CDATA[CH4]]> 11.618 Alkanes (C2~C5) 67.618 Alkenes (C2~C4) 7.743 <![CDATA[H2S]]> 0.099 carbonyl sulfide 0.038 <![CDATA[H2O]]> 0.015 total 100

[0057] Table 3. Composition of the product after hydrogenation 500 h after reaction

[0058] Product composition, mol% C-1 C-2 C-3 C-4 D-1 D-2 D-3 D-4 D-5 D-6 <![CDATA[H2]]> 2.293 3.028 3.118 2.507 4.739 5.404 4.877 4.422 4.764 4.851 <![CDATA[O2]]> 0 0 0 0 0.044 0.054 0.046 0.033 0.06 0.035 <![CDATA[N2]]> 0.029 0.026 0.026 0.026 0.026 0.026 0.026 0.026 0.026 0.026 CO 0 0 0 0 0.133 0.153 0.168 0.089 0.175 0.117 <![CDATA[CO2]]> 0 0 0 0 0.742 0.643 0.779 0.543 0.832 0.863 <![CDATA[CH4]]> 13.468 14.234 13.967 13.841 12.487 12.045 12.602 12.973 12.498 12.36 Alkanes (C2~C5) 81.769 80.576 80.666 81.581 79.191 78.256 78.77 79.323 78.621 78.93 Alkenes (C2~C4) 0.615 0.587 0.587 0.562 1.809 2.453 1.833 1.588 2.102 1.948 <![CDATA[H2S]]> 0.146 0.143 0.133 0.131 0.126 0.121 0.126 0.135 0.111 0.119 Organic sulfur 0 0 0 0 0 0 0 0 0.005 0.005 <![CDATA[H2O]]> 1.680 1.406 1.503 1.352 0.703 0.845 0.773 0.868 0.806 0.746 total 100 100 100 100 100 100 100 100 100 100

[0059] Table 4. Carbon deposits on the catalyst after hydrogenation

[0060] C-1 C-2 C-3 C-4 D-1 D-2 D-3 D-4 D-5 D-6 Carbon deposits, wt% 2.23 2.08 1.99 2.14 3.35 3.96 3.81 3.88 3.24 3.56

[0061] The evaluation results in Table 3 and the amount of carbon deposit on the catalyst after hydrogenation in Table 4 demonstrate that the catalyst of the present invention has better activity in olefin saturation and removal of impurities such as sulfur, oxygen, CO, and CO2, and the amount of carbon deposit is also lower after 500 hours of reaction, indicating that the catalyst has better stability.

Claims

1. A method for preparing a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons, characterized in that... The following are included: (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 an active component impregnation solution C containing quaternary ammonium salt compounds, drying, 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 E; (3) impregnating boehmite dry adhesive powder A with an active additive impregnation solution D, drying, and calcining it in a hydrogen atmosphere to obtain powder F; (4) mixing the powder E prepared in step (2) with the powder F prepared in step (3) evenly, and then molding, drying and calcining to obtain a dry gas hydrogenation catalyst for producing low-carbon hydrocarbons; the dry gas hydrogenation catalyst for producing low-carbon hydrocarbons includes a support component, an active component and an active additive; the support component is alumina; the active component is a group VIB metal sulfide and a group VIII metal sulfide, the average number of lamellar layers of the sulfide is <1.5 layers, and the single layer is <1.5 layers. The proportion is 70-85%; the active additive exists in metallic form and is selected from one or more of Cu, Ag, Ni, Co, W, and Mo; 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 active additive content in the catalyst is 0.1wt%-4wt%; the total acid content of the catalyst is 0.1-0.4mmol / g, of which the strong acid content at 400-500℃ accounts for 5-15%, the medium-strength acid content at 250-400℃ accounts for 10-20%, and the weak acid content at 150-250℃ accounts for 65%-85%; the acid content of the catalyst is tested by the NH3-TPD method; the high-temperature calcination temperature of step (1) is 800-1100℃, and the high-temperature calcination temperature of step (2) is 800-1100℃.

2. The method according to claim 1, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (1) is 10v%~30v, and the high-temperature calcination time is 0.5~5 hours.

3. The method according to claim 1, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (2) is 10v%~30v, and the high-temperature calcination time is 0.5~5 hours.

4. The method according to claim 1, 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.

5. The method according to claim 1, characterized in that: The active components mentioned in step (2) are Group VIB and Group VIII metals, wherein the Group VIB metal is Mo and / or W; and the Group VIII metal is Co and / or Ni.

6. The method according to claim 1, characterized in that: Step (2) The active component impregnation solution C is an aqueous solution of Group VIB and Group VIII metals, wherein a quaternary ammonium salt compound is added to adjust the pH value of the impregnation solution to 7.5~11.5; the quaternary ammonium salt compound has 4~19 carbons.

7. The method according to claim 1, characterized in that: The quaternary ammonium salt compound mentioned in step (2) is selected from one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, dodecyltrimethylammonium hydroxide, and hexadecyltrimethylammonium hydroxide.

8. The method according to claim 1, characterized in that: The calcination conditions in step (3) in a hydrogen atmosphere are: calcination temperature of 300~700℃ and calcination time of 2~5 hours.

9. The method according to claim 1, characterized in that: The impregnation methods in steps (2) and (3) are saturated impregnation or supersaturated impregnation.

10. The method according to claim 1, characterized in that: The drying conditions for steps (2), (3) and (4) are: drying time of 1 to 5 hours and drying temperature of 80 to 120°C.

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

12. A catalyst for dry gas hydrogenation to produce low-carbon hydrocarbons prepared by the method according to any one of claims 1 to 11, characterized in that: The catalyst comprises a support component, an active component, and an active promoter; the support component is alumina; the active component consists of Group VIB and Group VIII metal sulfides, with an average number of lamellar layers of <1.5 layers and a single-layer ratio of 70-85%; the active promoter exists in metallic form and is selected from one or more of Cu, Ag, Ni, Co, W, and Mo; based on the weight of the catalyst, Group VIB metal sulfides account for 1wt%-20wt% of the total catalyst mass, and Group VIII metal sulfides account for 0.5wt%-10wt% of the total catalyst mass; the active promoter content in the catalyst is 0.1wt%-4wt%; the total acid content of the catalyst is 0.1-0.4 mmol / g, of which strong acid at 400-500℃ accounts for 5-15%, moderately strong acid at 250-400℃ accounts for 10-20%, and weak acid at 150-250℃ accounts for 65%-85%.

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