Catalyst for hydrogenation of dry gas to low carbon hydrocarbons and method of preparation

Abstract

This invention discloses a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons and its preparation method. The catalyst comprises a support a of activated magnesium oxide and a support b of alumina; the active components are group VIB metal sulfides and group VIII metal sulfides, and the active promoters are one or more of Cu, Ag, Ni, Co, W, and Mo; the total acid content of the catalyst is 0.1~0.3 mmol / g, of which strong acids at 400-500℃ account for 5-15%, moderately strong acids at 250-400℃ account for 10-20%, and weak acids at 150-250℃ account for 65%-85%. The preparation method is as follows: the alumina and magnesium oxide impregnated with the active components are separately calcined at high temperatures, then mixed, and after molding, drying, and calcination, the catalyst is obtained. The catalyst prepared by this method exhibits excellent CO2 removal performance and does not have a particularly adverse effect on the removal of organic sulfur impurities and the hydrogenation saturation reaction of olefins, enabling the hydrogenation of dry gas with high CO2 content to produce low-carbon hydrocarbons.

Description

Technical Field

[0001] This invention relates to the field of hydrogenation of dry gas to produce low-carbon hydrocarbons, specifically to hydrogenation catalysts for processing dry gas with high CO2 content and their preparation methods. Background Technology

[0002] Impurities such as oxygen, sulfur, CO, and CO2 in dry gas are poisons for downstream units such as hydrogen production, causing catalyst poisoning in subsequent conversion processes. Simultaneously, olefins in dry gas can cause catalyst coking and carbon buildup during direct conversion. The hydrogenation process of dry gas requires the removal of impurities while simultaneously meeting olefin saturation requirements.

[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 CO2 is acidic and can be adsorbed onto strong bases, which is beneficial for its hydrogenation and removal. However, strong bases are not conducive to the removal of organic sulfur impurities and the hydrogenation saturation reaction of olefins. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes a catalyst and preparation method for the hydrogenation of dry gas to produce low-carbon hydrocarbons. The catalyst prepared by this method exhibits excellent CO2 removal performance and does not have a particularly significant adverse effect on the removal of organic sulfur impurities and the hydrogenation saturation reaction of olefins. It can handle the hydrogenation of dry gas with high CO2 content to produce low-carbon hydrocarbons.

[0008] The dry gas hydrogenation catalyst for producing low-carbon hydrocarbons of the present invention comprises a support a and a support b, an active component, and an active promoter; support a is active magnesium oxide, and support b is aluminum oxide; the active component is a Group VIB metal sulfide and a Group VIII metal sulfide, wherein the Group VIB metal is preferably Mo and / or W; the Group VIII metal is preferably Co and / or Ni; the active promoter is one or more of Cu, Ag, Ni, Co, W, and Mo; the average number of lamellar layers of the sulfide is <1.5 layers, and the proportion of single layers is 65-80%; the active promoter exists in a reduced state on the catalyst; based on the weight of the catalyst, the Group VIB metal sulfide accounts for 1wt% to 20wt% of the total mass of the catalyst, and the Group VIII metal sulfide accounts for 0.5wt% to 10wt% of the total mass of the catalyst. The content of the active additive is 0.2wt%~6wt%, preferably 0.5wt%~4wt%; the mass ratio of support component a to support component b is 1 / 4~3 / 2; the total acid content of the catalyst is 0.1~0.3mmol / g, of which the content of strong acid at 400-500℃ is 5~15%, the content of medium-strength acid at 250-400℃ is 10~20%, and the content of weak acid at 150-250℃ is 65%~85%.

[0009] The preparation method of the catalyst for dry gas hydrogenation to produce low-carbon hydrocarbons of the present invention includes the following:

[0010] (1) Take active magnesium oxide powder and calcine it in an oxygen-containing atmosphere to obtain active magnesium oxide dry adhesive powder A;

[0011] (2) Take the pseudo-boehmite dry adhesive powder and calcine it at high temperature in an oxygen-containing atmosphere to obtain alumina dry adhesive powder B;

[0012] (3) Impregnate alumina dry adhesive powder B with active component impregnation solution C, dry, calcine at high temperature in oxygen atmosphere, and then calcine in H2S and H2 mixed atmosphere to obtain powder E;

[0013] (4) Impregnate active magnesium oxide powder A with active additive impregnation solution D, dry, and calcine in hydrogen atmosphere to obtain powder F;

[0014] (5) After mixing the powder E prepared in step (3) with the powder F prepared in step (4) evenly, the powder is shaped, dried and calcined to obtain a catalyst for the production of low-carbon hydrocarbons by hydrogenation of dry gas.

[0015] In the method of the present invention, the active magnesium oxide powder in step (1) is a commercially available product or can be prepared by methods such as carbonate pyrolysis or magnesium alkoxide hydrolysis.

[0016] In the method of the present invention, the pseudo-boehmite dry adhesive powder mentioned in step (2) is a commercially available product, or it can be prepared by methods such as aluminum alkoxide method, sodium aluminate neutralization method, carbonization method, etc.

[0017] 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 calcination conditions are: calcination temperature of 300~700℃ and calcination time of 0.5~5 hours.

[0018] 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.

[0019] In the method of the present invention, the oxygen content in the oxygen-containing atmosphere in step (3) 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.

[0020] In the method of the present invention, the calcination conditions of the H2S and H2 mixed atmosphere in step (3) 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.

[0021] In the method of the present invention, the calcination conditions in the hydrogen atmosphere described in step (4) are: calcination temperature of 300~700℃ and calcination time of 2~5 hours.

[0022] In the method of this invention, the active component impregnation solution C in step (3) and the active auxiliary agent impregnation solution D in step (4) are both aqueous solutions prepared by conventional methods. For example, the active component impregnation solution C can be an aqueous solution prepared with salts such as ammonium molybdate, ammonium metatungstate, cobalt nitrate, nickel nitrate, basic cobalt carbonate, and basic nickel carbonate; the active auxiliary agent D can be an aqueous solution prepared with 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 added to the impregnation solution is calculated according to the content of each component on the catalyst.

[0023] In the method of the present invention, the impregnation method described in steps (3) and (4) 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.

[0024] In the method of this invention, the catalyst forming process described in step (5) is a method well known in the art, such as adding an extrusion aid to the composite 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.

[0025] In the method of the present invention, the drying conditions described in steps (3), (4) and (5) are: drying time of 1 to 5 hours and drying temperature of 80 to 120°C.

[0026] In the method of this invention, the calcination conditions in step (5) 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.

[0027] The dry gas hydrogenation catalyst of the present invention is applied to the dry gas hydrogenation reaction to produce low-carbon hydrocarbons under the following reaction conditions: 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.

[0028] 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 multilayer 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 metals, resulting in a single-layer structure of the metal sulfides formed after sulfidation, thus improving the stability of the catalyst's desulfurization and olefin saturation activity.

[0029] Furthermore, when the CO2 impurity content in the dry gas is too high, it cannot be completely removed due to the influence of diffusion and adsorption / desorption rates. Increasing the reaction temperature to improve the catalyst's hydrogenation performance can lead to the adverse effects of rapid exothermic hydrogenation of olefins and intensified condensation reactions. The inventors have employed active additives such as Cu, Ag, Ni, Co, W, and Mo, which have the advantage of adsorbing impurities such as oxygen, CO, and CO2 to facilitate hydrogenation reactions. Simultaneously, the treated activated magnesium oxide can be appropriately adjusted to improve the catalyst's adsorption capacity for CO2, which is beneficial for hydrogenating and converting CO2 impurities at lower temperatures. This avoids excessive exothermic hydrogenation of olefins and the formation of carbon deposits due to condensation at high temperatures, further extending the catalyst's lifespan. Attached Figure Description

[0030] Figure 1 The image shows the XPS spectrum of the catalyst in Example 1, used to characterize the valence states of the active metals on the catalyst. Detailed Implementation

[0031] The following examples further illustrate the solution and effects of the present invention, but do not constitute a limitation on the present invention.

[0032] In this invention, commercially available magnesium oxide powder and pseudoboehmite dry binder powder purchased from Sinopec Catalyst Dalian Branch were selected. The magnesium oxide powder has a specific surface area of ​​10² m². 2 / g, pore volume 0.55 cm³ 3 / g, with a pore size of 21.5nm. The specific surface area of ​​the pseudoboehmite dry adhesive powder is 392 m². 2 / g, pore volume 0.95 cm³ 3 / g, pore size 9.7nm. The acidity of the catalyst was tested by NH3-TPD method. The metal content on the catalyst was analyzed by X-ray fluorescence spectrometry. The number of lamellar layers of sulfides on the catalyst was obtained by statistical analysis of TEM images. The components of the raw materials and products were obtained by normalization calculation after chromatographic analysis.

[0033] Example 1

[0034] Take 26.2g of ammonium heptamolybdate and 20.7g of cobalt nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 120mL aqueous solution of the active component C. Take 12.7g of copper nitrate and 5.7g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 70mL aqueous solution of the auxiliary component D. Then, take a certain amount of the above magnesium oxide powder and calcine it in air at 600℃ for 2 hours to obtain active magnesium oxide powder A; take a certain amount of the above pseudoboehmite dry adhesive powder and calcine it in air at 1000℃ for 2 hours to obtain alumina dry adhesive powder B. Load 100g of the calcined alumina dry adhesive powder B with the aqueous solution of the active component C, dry it at 100℃ for 3 hours, calcine it in air at 900℃ for 1.5 hours, and then treat it at 350℃ in a mixed atmosphere of 1% H2S and H2 for 4 hours to obtain powder E. 80g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary agent component D and dried at 100℃ for 3h. Then, it was calcined at 650℃ in a hydrogen atmosphere for 3.5h 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 150mL 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 C-1.

[0035] Example 2

[0036] Take 22.7g of ammonium metatungstate, 6.5g of ammonium heptamolybdate, and 19.0g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare an 80mL aqueous solution C of the active component. Take 5.8g of copper nitrate and 2.0g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 42mL aqueous solution D of the auxiliary component. Then, take a certain amount of the above magnesium oxide powder and calcine it in air at 400℃ for 3h to obtain active magnesium oxide powder A; take a certain amount of the above pseudoboehmite dry adhesive powder and calcine it in air at 800℃ for 5h to obtain alumina dry adhesive powder B. Load 100g of the calcined alumina dry adhesive powder B with the aqueous solution C of the active component, dry it at 110℃ for 3h, calcine it in air at 900℃ for 4h, and then treat it at 500℃ in a mixed atmosphere of 1% H2S and H2 for 4h to obtain powder E. 60g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary agent component D and dried at 110℃ for 3h. Then, it was calcined at 400℃ 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 1.7g of guar gum powder, 14g of 10% nitric acid and 130mL 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.

[0037] Example 3

[0038] Take 26.5g of ammonium heptamolybdate and 24.5g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 100mL aqueous solution of the active component C. Take 6.9g of silver nitrate and 10.8g of cobalt nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 75mL aqueous solution of the auxiliary component D. Then, take a certain amount of the above magnesium oxide powder and calcine it in air at 500℃ for 3h to obtain active magnesium oxide powder A; take a certain amount of the above pseudoboehmite dry adhesive powder and calcine it in air at 900℃ for 3h to obtain alumina dry adhesive powder B. Load 80g of the calcined alumina dry adhesive powder B with the aqueous solution of the active component C, dry it at 110℃ for 2h, calcine it in air at 1050℃ for 3h, and then treat it at 400℃ in a mixed atmosphere of 1% H2S and H2 for 5h to obtain powder E. 100g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary component D and dried at 110℃ for 2h. Then, it was calcined at 550℃ 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 1.9g of guar gum powder, 16g of 10% nitric acid and 120mL of deionized water were added. After molding, the mixture was dried at 110℃ for 2h and then calcined at 300℃ in a nitrogen atmosphere for 2h to obtain the final catalyst C-3.

[0039] Example 4

[0040] Take 20.5g of ammonium metatungstate, 7.8g of ammonium heptamolybdate, and 22.7g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 120mL aqueous solution of the active component C. Take 7.9g of copper nitrate, dissolve it in an appropriate amount of water, and prepare an 80mL aqueous solution of the auxiliary component D. Then, take a certain amount of the above magnesium oxide powder and calcine it in air at 500℃ for 3 hours to obtain active magnesium oxide powder A; take a certain amount of the above pseudoboehmite dry adhesive powder and calcine it in air at 900℃ for 5 hours to obtain alumina dry adhesive powder B. Load 100g of the calcined alumina dry adhesive powder B with the aqueous solution of the active component C, dry it at 90℃ for 4 hours, calcine it in air at 850℃ for 4 hours, and then treat it at 300℃ in a mixed atmosphere of 1% H2S and H2 for 7 hours to obtain powder E. 40g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary component D and dried at 90℃ for 4h. Then, it was calcined at 450℃ 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 2.0g of guar gum powder, 14g of 10% nitric acid and 150mL 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.

[0041] Comparative Example 1

[0042] The preparation method of Example 1 was followed, but without the addition of any auxiliary components. 26.2 g of ammonium heptamolybdate and 20.7 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 120 mL of an aqueous solution C containing the active component. Then, a certain amount of the above-mentioned magnesium oxide powder was calcined at 600°C in air for 2 hours to obtain active magnesium oxide powder A; a certain amount of the above-mentioned boehmite dry adhesive powder was calcined at 1000°C in air for 2 hours to obtain alumina dry adhesive powder B. 100 g of the calcined alumina dry adhesive powder B was loaded with the aqueous solution C containing the active component, dried at 100°C for 3 hours, calcined at 900°C in air for 1.5 hours, and then treated at 350°C in a mixed atmosphere of 1% H2S and H2 for 4 hours to obtain powder E. Powder E and 80g of active magnesium oxide powder A were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 15g of 10% nitric acid and 150mL 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-1.

[0043] Comparative Example 2

[0044] The preparation method of Example 1 was followed, but without using magnesium oxide powder as a carrier. 26.2 g of ammonium heptamolybdate and 20.7 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 120 mL aqueous solution C of the active component. 12.7 g of copper nitrate and 5.7 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 70 mL aqueous solution D of the auxiliary component. Then, a certain amount of the above-mentioned pseudoboehmite dry adhesive powder was calcined at 1000°C in air for 2 hours to obtain alumina dry adhesive powder A. 100 g of the calcined alumina dry adhesive powder A was loaded with the aqueous solution C of the active component, dried at 100°C for 3 hours, calcined at 900°C in air for 1.5 hours, and then treated at 350°C in a mixed atmosphere of 1% H2S and H2 for 4 hours to obtain powder E. 80g of alumina dry adhesive powder A was loaded with an aqueous solution of auxiliary agent component D and dried at 100℃ for 3h. Then, it was calcined at 350℃ in a hydrogen atmosphere for 3.5h 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 150mL 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.

[0045] Comparative Example 3

[0046] The preparation method of Example 1 was followed, but the alumina support was not subjected to high-temperature calcination during the preparation process. 26.2 g of ammonium heptamolybdate and 20.7 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 120 mL aqueous solution C of the active component. 12.7 g of copper nitrate and 5.7 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 70 mL aqueous solution D of the auxiliary component. Then, a certain amount of the above magnesium oxide powder was calcined at 600°C in air for 2 hours to obtain active magnesium oxide powder A. 142.9 g of boehmite dry adhesive powder loaded with the active component aqueous solution C was dried at 100°C for 3 hours, then calcined at 900°C in air for 1.5 hours, and then treated at 350°C in a mixed atmosphere of 1% H2S and H2 for 4 hours to obtain powder E. 80g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary component D and dried at 100℃ for 3h. Then, it was calcined at 350℃ in a hydrogen atmosphere for 3.5h 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 150mL 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-3.

[0047] Comparative Example 4

[0048] The preparation method of Example 1 was followed, but in step (2), the pseudoboehmite powder was calcined at low temperature to form γ-alumina before impregnation. 26.2g of ammonium heptamolybdate and 20.7g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 120mL of active component aqueous solution C. 12.7g of copper nitrate and 5.7g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 70mL of auxiliary component aqueous solution D. Then, a certain amount of magnesium oxide powder was calcined at 600℃ in air for 2h to obtain active magnesium oxide powder A; a certain amount of the above pseudoboehmite dry adhesive powder was calcined at 550℃ in air for 3h to obtain γ-alumina dry adhesive powder. 100g of γ-alumina powder was impregnated with an aqueous solution of the active component C, dried at 100℃ for 3h, calcined at 900℃ in air for 1.5h, and then treated at 350℃ in a mixed atmosphere of 1% H2S and H2 for 4h to obtain powder E. 80g of magnesium oxide powder A was loaded with an aqueous solution of the auxiliary component D, dried at 100℃ for 3h, and then calcined at 350℃ in a hydrogen atmosphere for 3.5h 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 150mL 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-4.

[0049] Comparative Example 5

[0050] 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. 26.2 g of ammonium heptamolybdate and 20.7 g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 120 mL aqueous solution C of the active component. 12.7 g of copper nitrate and 5.7 g of nickel nitrate hexahydrate were dissolved in an appropriate amount of water to prepare a 70 mL aqueous solution D of the auxiliary component. Then, a certain amount of the above magnesium oxide powder was calcined at 600°C in air for 2 hours to obtain active magnesium oxide powder A; a certain amount of the above boehmite dry adhesive powder was calcined at 1000°C in air for 2 hours to obtain alumina dry adhesive powder B. 100 g of the calcined alumina dry adhesive powder B was loaded with the aqueous solution C of the active component, dried at 100°C for 3 hours, and then treated at 350°C in a mixed atmosphere of 1% H2S and H2 for 4 hours to obtain powder E. 80g of magnesium oxide powder A was loaded with an aqueous solution of auxiliary agent component D and dried at 100℃ for 3h. Then, it was calcined at 350℃ in a hydrogen atmosphere for 3.5h 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 150mL of deionized water were added. After shaping, it was dried at 100℃ for 3h and then calcined at 350℃ in a nitrogen atmosphere for 2h to obtain the final catalyst D-5.

[0051] Comparative Example 6

[0052] The preparation method of Example 1 was followed, but the carrier was prepared first, followed by stepwise impregnation of the active metal component and the auxiliary component. A certain amount of the above magnesium oxide powder was calcined in air at 600°C for 2 hours to obtain active magnesium oxide powder A; a certain amount of the above boehmite dry adhesive powder was calcined in air at 1000°C for 2 hours to obtain alumina dry adhesive powder B. Then, 80g of magnesium oxide powder A and 100g of calcined alumina dry adhesive powder B were mixed evenly, pulverized and sieved (200 mesh), and then 2g of guar gum powder, 15g of 10% nitric acid and 150mL of deionized water were added. After molding, the mixture was dried at 100°C for 3 hours and then calcined in air at 350°C for 2 hours to obtain the catalyst carrier. 26.2g of ammonium heptamolybdate and 20.7g of cobalt nitrate hexahydrate were dissolved in an appropriate amount of water to prepare 120mL of active component aqueous solution C. Take 12.7g of copper nitrate and 5.7g of nickel nitrate hexahydrate, dissolve them in an appropriate amount of water, and prepare a 70mL aqueous solution of the auxiliary component D. Impregnate the prepared support with the loading solution C, dry it at 100℃ for 3h, calcine it at 900℃ in air for 1.5h, and then treat it at 350℃ in a mixed atmosphere of 1% H2S and H2 for 4h to obtain a first-stage catalyst. Load the first-stage catalyst with the aqueous solution of the auxiliary component D, dry it at 100℃ for 3h, and then calcine it at 350℃ in a nitrogen atmosphere for 3.5h to obtain the finished catalyst D-6.

[0053] The component content and properties of each catalyst are listed in Table 1.

[0054] Table 1. Catalyst component content and properties in the examples and comparative examples

[0055] C-1 C-2 C-3 C-4 D-1 D-2 D-3 D-4 D-5 D-6 Group VIB sulfides, wt% 11.0 15.0 11.0 16.0 11.3 11.0 11.0 11.0 11.0 11.0 Group VIII sulfides, wt% 3.0 3.0 3.5 4.0 3.1 3.0 3.0 3.0 3.0 3.0 Active ingredient c, wt% 2.5 0.8 3.0 1.5 0 2.5 2.5 2.5 2.5 2.5 MgO / Al2O3 0.8 0.6 1.25 0.4 0.8 0 0.8 0.8 0.8 0.8 Total acid content, mmol / g 0.26 0.13 0.19 0.15 0.27 0.35 0.32 0.31 0.21 0.20 Strong acid content at 400-500℃, % 9.2 11.3 8.4 12.8 9.8 7.4 5.0 5.5 6.3 6.1 Medium strength acidity at 250-400℃, % 16.5 12.4 17.6 14.9 15.8 19.2 26.4 30.6 28.8 20.1 Average number of lamellar layers of sulfides 1.3 1.3 1.3 1.3 1.5 1.4 1.8 1.9 1.7 1.6 Sulfide monolayer percentage, % 72 69 74 70 56 61 40 33 47 52

[0056] The above catalyst was subjected to an activity evaluation test in a 10 mL reaction apparatus at a reaction pressure of 2.5 MPa, a reaction temperature of 210 °C, and a gas hourly space velocity of 900 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.

[0057] Table 2 Composition of Coking Dry Gas Feedstock

[0058] composition Content, mol% <![CDATA[H2]]> 12.021 <![CDATA[O2]]> 0.164 <![CDATA[N2]]> 0.026 CO 0.213 <![CDATA[CO2]]> 1.245 <![CDATA[CH4]]> 11.618 Alkanes (C2~C5) 69.837 Alkenes (C2~C4) 4.724 <![CDATA[H2S]]> 0.099 carbonyl sulfide 0.038 <![CDATA[H2O]]> 0.015 total 100

[0059] Table 3. Composition of the product after hydrogenation 500 h after reaction

[0060] 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]]> 2.038 2.948 3.227 2.427 4.339 4.404 4.177 3.707 3.964 4.551 <![CDATA[O2]]> 0 0 0 0 0.044 0.054 0.046 0.023 0.06 0.035 <![CDATA[N2]]> 0.028 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 0.131 0.175 0.117 <![CDATA[CO2]]> 0 0 0 0 0.742 0.643 0.779 0.542 0.832 0.863 <![CDATA[CH4]]> 14.099 14.007 15.664 14.364 13.087 13.045 13.102 13.613 13.498 13.36 Alkanes (C2~C5) 79.819 79.085 79.273 79.273 77.691 77.256 77.47 77.842 76.621 75.93 Alkenes (C2~C4) 0.605 0.623 0.299 0.699 1.209 1.453 1.333 1.119 1.902 2.248 <![CDATA[H2S]]> 0.143 0.138 0.14 0.14 0.126 0.121 0.126 0.141 0.111 0.119 Organic sulfur 0 0 0 0 0 0 0 0 0.005 0.005 <![CDATA[H2O]]> 3.268 3.173 1.371 3.071 2.603 2.845 2.773 2.856 2.806 2.746 total 100 100 100 100 100 100 100 100 100 100

[0061] Table 4. Carbon deposits on the catalyst after hydrogenation

[0062] C-1 C-2 C-3 C-4 D-1 D-2 D-3 D-4 D-5 D-6 Carbon deposits, wt% 2.01 1.93 2.06 2.11 3.42 3.98 3.86 3.81 3.47 3.79

[0063] 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 catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons, characterized in that: The catalyst comprises support a and support b, active components, and active additives; support a is active magnesium oxide, support b is alumina, and the active components are Group VIB and Group VIII metal sulfides, with an average number of lamellar layers of <1.5 layers and a single-layer ratio of 65-80%; the active additives are one or more of Cu, Ag, Ni, Co, W, and Mo; the active additives exist in a reduced state on the catalyst; based on the weight of the catalyst, the Group VIB metal sulfides constitute the total mass of the catalyst. The amount of catalyst is 1wt%~20wt%, and the amount of group VIII metal sulfides is 0.5wt%~10wt% of the total catalyst mass; the content of active promoters is 0.2wt%~6wt%; the mass ratio of support a to support b is 1 / 4~3 / 2; the total acid content of the catalyst is 0.1~0.3mmol / g, of which the content of strong acid at 400-500℃ is 5~15%, the content of medium-strength acid at 250-400℃ is 10~20%, and the content of weak acid at 150-250℃ is 65%~85%.

2. The catalyst according to claim 1, characterized in that: Group VIB metals are Mo and / or W; Group VIII metals are Co and / or Ni.

3. The catalyst according to claim 1, characterized in that: The content of active additives is 0.5wt%~4wt%.

4. A method for preparing a catalyst for the hydrogenation of dry gas to produce low-carbon hydrocarbons according to any one of claims 1 to 3, characterized in that... The following contents are included: (1) Take active magnesium oxide powder and calcine it in an oxygen-containing atmosphere to obtain active magnesium oxide dry adhesive powder A; (2) Take boehmite dry adhesive powder and calcine it at high temperature in an oxygen-containing atmosphere to obtain alumina dry adhesive powder B; (3) 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 E; (4) Impregnate active magnesium oxide dry adhesive powder A with active auxiliary impregnation liquid D, dry it, and calcine it in a hydrogen atmosphere to obtain powder F; (5) Mix the powder E prepared in step (3) and the powder F prepared in step (4) evenly, and then shape, dry and calcine to obtain a catalyst for the production of low-carbon hydrocarbons by hydrogenation of dry gas.

5. The method according to claim 4, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (1) is 10v%~30v%, and the calcination conditions are: calcination temperature of 300~700℃ and calcination time of 0.5~5 hours.

6. The method according to claim 4, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (2) is 10v%~30v%, and 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 4, characterized in that: The oxygen content in the oxygen-containing atmosphere described in step (3) is 10v%~30v%, and the high-temperature calcination conditions are: calcination temperature of 800~1100℃ and calcination time of 0.5~5 hours.

8. The method according to claim 4, characterized in that: The calcination conditions in step (3) in the mixed atmosphere of H2S and H2 are: calcination temperature of 250~550℃, calcination time of 3~8 hours; wherein the proportion of H2S in the mixed atmosphere of H2S and H2 is 0.1v%~2v.

9. The method according to claim 4, characterized in that: The conditions for calcination in step (4) in a hydrogen atmosphere are: calcination temperature of 300~700℃ and calcination time of 2~5 hours.

10. The method according to claim 4, characterized in that: The impregnation methods in steps (3) and (4) are saturated impregnation or supersaturated impregnation.

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

12. The method according to claim 4, characterized in that: The calcination conditions for step (5) 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.

13. The application of the catalyst for the hydrogenation of dry gas to low-carbon hydrocarbons according to any one of claims 1 to 3 in the reaction of hydrogenation of dry gas to low-carbon hydrocarbons, wherein the reaction conditions are: reaction pressure 0.1 to 10 MPa, gas hourly space velocity 300 to 10000 h⁻¹ -1 The reaction temperature is 150~400℃.

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