阅读说明：本技术 一种加氢脱硫催化剂及其制备方法 (Hydrodesulfurization catalyst and preparation method thereof ) 是由 郭蓉 姚运海 王震 杨成敏 刘丽 段为宇 周勇 丁莉 孙进 郑步梅 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种加氢脱硫催化剂及其制备方法。以催化剂总重量为基准,MoS-2为1.0%～19.0%,Co-9S-8为0.1%～7.0%,MoO-3为1.0%～10.0%,碳含量为0.5%～18.0%；所述的载体为无机耐熔氧化物,含量为56%～97.4%。加氢脱硫催化剂的制备方法,包括如下内容：(1)用含有活性金属Co和Mo的浸渍液I浸渍载体,浸渍后载体经干燥和焙烧后,用液态烯烃饱和浸渍,然后热处理,再进行硫化处理；(2)用含有活性金属Mo的浸渍液II浸渍步骤(1)得到的硫化物料,经干燥后,得到加氢脱硫催化剂。本发明的加氢脱硫催化剂的活性组分具有不同的存在形式,该催化剂在汽油选择性加氢脱硫过程中具有高活性、汽油加氢选择性和高稳定性。(The invention discloses a hydrodesulfurization catalyst and a preparation method thereof. Based on the total weight of the catalyst, MoS 2 1.0% -19.0% of Co 9 S 8 0.1% -7.0% of MoO 3 1.0-10.0% of carbon, 0.5-18.0% of carbon; the carrier is an inorganic refractory oxide, and the content of the inorganic refractory oxide is 56-97.4%. The preparation method of the hydrodesulfurization catalyst comprises the following steps: (1) impregnating a carrier with an impregnation liquid I containing active metals Co and Mo, drying and roasting the impregnated carrier, saturating and impregnating the impregnated carrier with liquid olefin, then carrying out heat treatment, and then carrying out vulcanization treatment; (2) and (2) dipping the vulcanized material obtained in the step (1) by using dipping liquid II containing active metal Mo, and drying to obtain the hydrodesulfurization catalyst. The active components of the hydrodesulfurization catalyst of the invention have different forms of presence, and the catalyst is selected from gasolineThe process has high activity, gasoline hydrogenation selectivity and stability.)

1. A hydrodesulfurization catalyst characterized by: based on the total weight of the catalyst, MoS₂1.0% -19.0% of Co₉S₈0.1% -7.0% of MoO₃1.0-10.0 percent of carbon, 0.5-18.0 percent of carbon and 56-97.4 percent of carrier; the carrier is inorganic refractory oxide, and is selected from one or more of alumina, silica, zirconia, titania or magnesia.

2. The catalyst of claim 1, wherein: based on the total weight of the catalyst, MoS₂1.0% -16.0% of Co₉S₈0.1% -6.0% of MoO₃1.0-8.0% and 0.5-18.0% of carbon.

3. The catalyst of claim 1, wherein: the pore volume is 0.3-1.3 mL/g, the specific surface area is 150-400 m²Strength/g100 to 250N/cm, and a bulk density of 0.65 to 0.90 g/mL.

4. The catalyst of claim 1, wherein: the hydrodesulfurization catalyst contains an auxiliary agent, the auxiliary agent is selected from one or more of K, Na, Mg, Si, P, Zr or Ti, the addition amount of the auxiliary agent is 1.0-10% by weight of oxides based on the total weight of the catalyst, and the sum of the contents of all the components of the catalyst is 100%.

5. A method for preparing a hydrodesulfurization catalyst according to any one of claims 1 to 3, characterized by comprising: (1) impregnating a carrier with an impregnation liquid I containing active metals Co and Mo, drying and roasting the impregnated carrier, saturating and impregnating the impregnated carrier with liquid olefin, then carrying out heat treatment, and then carrying out vulcanization treatment; (2) and (2) dipping the vulcanized material obtained in the step (1) by using dipping liquid II containing active metal Mo, and drying to obtain the hydrodesulfurization catalyst.

6. The method of claim 5, wherein: the drying conditions in the step (1) are as follows: drying for 1-5 hours at 100-120 ℃, wherein the roasting conditions are as follows: roasting at 400-550 ℃ for 1-5 hours.

7. The method of claim 5, wherein: the liquid olefin in the step (1) is one or more of olefin with 2-10 carbon atoms and diene.

8. The method of claim 5, wherein: the liquid olefin in the step (1) is hexadiene and/or n-heptene.

9. The method of claim 5, wherein: the heat treatment process in the step (1) comprises the following steps: heating at 50-250 ℃ for 1-8 h, heating to 250-300 ℃ for 1-72 h, and then heating to 300-400 ℃ for 1-72 h.

10. The method of claim 5, wherein: the vulcanizing treatment in the step (1) adopts one or more vulcanizing agents selected from carbon disulfide, dimethyl disulfide, methyl sulfide or n-butyl sulfide.

11. The method of claim 5, wherein: the amount of the vulcanizing agent introduced in the vulcanization treatment in the step (1) is 90-150% of the theoretical sulfur demand of the catalyst, and the temperature is raised to 200-350 ℃ by adopting a temperature program in the vulcanization process and is kept constant for 1-16 h.

12. The method of claim 5, wherein: the drying conditions in the step (2) are as follows: drying for 1-5 hours at 100-120 ℃.

13. Use of a hydrodesulfurization catalyst according to any one of claims 1 to 3 in the selective hydrodesulfurization of gasoline.

14. A hydrodesulfurization catalyst according to any one of claims 1 to 3, characterized in that: after the hydrodesulfurization catalyst is vulcanized, the active phase MoS₂The average length of the platelets is 4-14 nm, the preferred length is 7-11 nm, the average number of the platelets in a single stack layer is 1-12, the preferred number is 5.5-12, and the proportion of the stack layers with the number of layers larger than 5 is 15% -30% based on the total number of the stack layers.

Technical Field

The invention relates to a hydrodesulfurization catalyst and a preparation method thereof.

Background

In order to protect the environment, the restrictions on the amount of harmful substances discharged from automobile exhaust gas in various countries in the world are becoming more and more strict. Reducing the sulfur content in gasoline will effectively reduce the harmful substance emission in automobile exhaust. Consequently, clean gasoline in countries around the world has increasingly lower sulfur content. The reduction of the sulfur content of gasoline has become a great trend worldwide, and is an important subject of the technical progress of gasoline quality in China.

China has a great difference in gasoline composition compared with foreign countries. The catalytic cracking gasoline (FCC gasoline) in gasoline of most of the refining enterprises in China accounts for about 80 percent, and the proportion of other gasoline is very small. The FCC gasoline has the characteristics of high sulfur, high olefin and the like, and more than 80 percent of sulfur and olefin in the motor gasoline come from the FCC gasoline, so that the reduction of the sulfur content of the FCC gasoline is the key for meeting the increasingly strict standard requirement in the future.

In recent years, a plurality of FCC gasoline selective hydrodesulfurization technologies with small octane number loss, such as OCT-M, OCT-MD, RSDS-II, Prime-G +, CDhydro/CDHDS and the like, are successfully developed at home and abroad. The core unit of the technologies can not be separated from the heavy gasoline fraction selective hydrodesulfurization unit, and the effective improvement of the hydrodesulfurization selectivity of the heavy gasoline is the key for producing the European V emission standard clean gasoline. Thus, the development of a high selectivity heavy gasoline hydrodesulfurization catalyst is of great importance.

CN102049270A discloses a gasoline selective hydrodesulfurization catalyst and a preparation method thereof. The carrier of the catalyst is alumina modified by carbon and silicon oxide in a specific ratio, the silicon oxide is added to adjust the acid distribution of the carrier, particularly the L acid content is greatly increased, the carbon is added to inhibit the hydrogenation activity of olefin through selective interaction with the hydrogenation activity center of the olefin, the selective hydrodesulfurization capacity of the catalyst is improved, the effect of the carrier on auxiliary agent potassium is enhanced, the carrier and the auxiliary agent phosphorus are coordinated, the potassium loss is prevented, and the stability of the catalyst is improved. The disadvantage is that the addition of activated carbon in this way has a limited effect on the inhibition of the olefin saturation activity. The activity and hydrodesulfurization selectivity of the catalyst are yet to be further improved.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of a hydrodesulfurization catalyst. The active components of the hydrodesulfurization catalyst have different existing forms, and the catalyst has high activity, gasoline hydrogenation selectivity and high stability in the gasoline selective hydrodesulfurization process.

The hydrodesulfurization catalyst of the invention takes the total weight of the catalyst as a reference, and MoS₂1.0-19.0%, preferably 1.0-16.0%, Co₉S₈0.1% -7.0%, preferably 0.1% -6.0%, MoO₃1.0-10.0%, preferably 1.0-8.0%, carbon content 0.5-18.0%, and carrier content 56-97.4%; the carrier is inorganic refractory oxide, is selected from one or more of alumina, silica, zirconia, titania or magnesia, and is preferably alumina.

The hydrodesulfurization catalyst has the pore volume of 0.3-1.3 mL/g and the specific surface area of 150-400 m²(iv) g, strength of 100 to 250N/cm, and bulk density of 0.65 to 0.90 g/mL.

The hydrodesulfurization catalyst can also be added with an auxiliary agent according to the requirement, such as one or more of auxiliary agent elements such as K, Na, Mg, Si, P, Zr or Ti, and the like, wherein the addition amount of the auxiliary agent is 1.0-10% by weight of an oxide and the sum of the contents of all components of the catalyst is 100% by taking the total weight of the catalyst as a reference.

The preparation method of the hydrodesulfurization catalyst comprises the following steps:

(1) impregnating a carrier with an impregnation liquid I containing active metals Co and Mo, drying and roasting the impregnated carrier, saturating and impregnating the impregnated carrier with liquid olefin, then carrying out heat treatment, and then carrying out vulcanization treatment;

(2) and (2) dipping the vulcanized material obtained in the step (1) by using dipping liquid II containing active metal Mo, and drying to obtain the hydrodesulfurization catalyst.

In the method of the invention, the carrier in the step (1) is an inorganic refractory oxide, and is selected from one or more of alumina, silica, zirconia, titania and magnesia, preferably alumina. The carrier can be modified by adding an auxiliary agent, and the modifying auxiliary agent can be K, Na, Mg, Si, P, Zr and Ti.

In the method of the present invention, the preparation method of the impregnation solution I containing the active metals Co and Mo is well known to those skilled in the art, and for example, the following method can be adopted: dissolving citric acid in purified water, adding cobalt carbonate, boiling to dissolve, cooling, adding ammonia water, adding ammonium molybdate into the above solution, dissolving, adjusting the volume of the solution to the final volume with ammonia water, and sealing for storage.

In the method of the invention, the drying conditions in the step (1) are as follows: drying for 1-5 hours at 100-120 ℃, wherein the roasting conditions are as follows: roasting at 400-550 ℃ for 1-5 hours.

In the method, the liquid olefin in the step (1) is one or more of olefin and diene with 2-10 carbon atoms, and is preferably hexadiene and/or n-heptene.

In the method, the heat treatment process in the step (1) comprises the following steps: heating at 50-250 ℃ for 1-8 h, heating to 250-300 ℃ for 1-72 h, and then heating to 300-400 ℃ for 1-72 h.

In the method, the vulcanizing treatment in the step (1) adopts an in-situ or ex-situ vulcanizing process, the amount of the introduced vulcanizing agent is 90-150% of the theoretical sulfur demand of the catalyst, and the vulcanizing process adopts temperature programming, wherein the temperature is raised to 200-350 ℃ and is kept constant for 1-16 hours. The vulcanizing agent is typically one or more of carbon disulfide, dimethyl disulfide, methyl sulfide, n-butyl sulfide.

In the method of the present invention, the impregnation solution II containing the active metal Mo in the step (2) is prepared by adding molybdenum trioxide to an aqueous ammonia solution to a final volume.

In the method of the invention, the drying conditions in the step (2) are as follows: drying for 1-5 hours at 100-120 ℃.

The hydrodesulfurization catalyst is suitable for application in selective hydrodesulfurization of gasoline, and needs to be subjected to vulcanization treatment before application, wherein the vulcanization treatment process adopts a vulcanization treatment mode in the step (1).

After the hydrodesulfurization catalyst of the invention is vulcanized, the active phase MoS₂The average length of the platelets is 4-14 nm, the preferred length is 7-11 nm, the average number of the platelets in a single stack layer is 1-12, the preferred number is 5.5-12, and the proportion of the stack layers with the number of layers larger than 5 is 15% -30% based on the total number of the stack layers.

In the selective hydrogenation process of gasoline, how to inhibit the hydrogenation saturation of olefin while ensuring the hydrodesulfurization performance of the catalyst is always a contradiction which is difficult to balance. The inventor finds that, through a large number of experiments, the Mo active metal is harder to vulcanize than the active metal Co, and the phenomenon that the vulcanized Co active metal is wrapped by the vulcanized Mo active metal is easily caused, so that the activity of the catalyst is influenced. The catalyst is a sulfide-oxide composite catalyst, the method of impregnating Mo active metal on vulcanized Mo and Co active metal is adopted, the Mo active metal and the active metal Co are partially impregnated at first, then the selectivity of the catalyst is increased in a special carbon deposition mode, and then the vulcanization operation is carried out, so that the phenomenon that the vulcanized Co active metal is wrapped by the vulcanized Mo active metal can be avoided, the surface of a carrier can be covered with a strong adsorption site, the interaction force between the subsequent impregnated active metal and the surface of the carrier is weakened, the hydrogenation selectivity of gasoline is increased, the subsequent dispersion of the Mo active metal is facilitated, the auxiliary effect of the Mo active metal can be fully exerted, and the activity of the catalyst is improved on the basis of inhibiting the olefin saturation performance. The catalyst with the structure not only ensures the hydrodesulfurization activity, but also better inhibits the saturation of olefin and has better hydrodesulfurization selectivity.

Drawings

FIG. 1 is a transmission electron micrograph of a catalyst of example 1 of the present invention.

FIG. 2 is a transmission electron micrograph of the comparative example 1 catalyst.

Detailed Description

In the present invention, the specific surface area and the pore volume are measured by a low-temperature liquid nitrogen adsorption method. The strength is measured by an intelligent particle strength measuring instrument, and the bulk density is measured by a measuring cylinder method. The catalyst composition of the invention is characterized by combining inductively coupled plasma ICP and XPS energy spectra. The length of the platelets and the layer number of the stacks were determined using a field emission transmission electron microscope [ more than 350 MoS selected ]₂Counting and arranging the average layer number, the average length and the proportion of wafers larger than 5 layers of the wafers, wherein the statistical formula is as follows:

and

wherein l_iRepresenting the wafer length, N_iRepresents the number of i layers, a_iRepresentative wafer l_iNumber of (a), (b)_iNumber of representative layers N_iThe number of (2). [ MEANS FOR solving PROBLEMS ] is provided. In the present invention, wt% means mass percentage.

The specific preparation process of the catalyst of the invention is as follows:

putting a carrier into a rolling pot, spraying Mo and Co ammonia solution with saturated water absorption of the carrier into the carrier in an atomization mode under a rotating condition, after the solution is sprayed, continuously rotating the carrier in the rolling pot for 10-60 minutes, then standing the carrier for 1-24 hours, drying the carrier for 1-5 hours at 100-120 ℃, then raising the temperature to 400-550 ℃ at a heating rate of 150-250 ℃/hour, roasting the carrier for 1-5 hours, then saturated dipping the carrier by liquid olefin, heating the carrier for 1-8 hours at 50-250 ℃, raising the temperature to 250-300 ℃, heating for 1-72 hours, raising the temperature to 300-400 ℃, and heating for 1-72 hours to perform heat treatment; then carrying out vulcanization treatment by adopting an in-situ or out-situ vulcanization process, wherein the amount of the introduced vulcanizing agent is 90-150% of the theoretical sulfur demand of the catalyst, and the temperature is raised to 200-350 ℃ by adopting a temperature program in the vulcanization process and is kept constant for 1-16 h; and (3) placing the obtained vulcanized material in a rolling pot, spraying an ammonia solution of Mo with saturated water absorption of the vulcanized material into the rolling pot in an atomization mode under a rotating condition, continuing to rotate in the rolling pot for 10-60 minutes after the solution is sprayed, then standing for 1-24 hours, drying for 1-5 hours at 100-120 ℃, and then raising the temperature to 400-550 ℃ at a heating rate of 150-250 ℃/hour and roasting for 1-5 hours to obtain the finished catalyst.

In the above preparation method, the concentration of the impregnation liquid is determined by the water absorption and the desired composition (content) of the catalyst.

The catalyst used in the present invention will be specifically described below with reference to examples.

Example 1

Dissolving 16.8g of citric acid in 90mL of purified water, adding 12.5g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 13.3g of ammonium molybdate into the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of carrier is placed in a rolling pot, spraying and soaking are carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at 110 ℃, then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and roasted for 3 hours, then the carrier is placed in 600mL of hexadiene solvent for soaking for 4 hours, then the carrier is heated to 200 ℃ for 4 hours, then the carrier is heated to 300 ℃ for 24 hours, and then the carrier is heated to 400 ℃ for 10 hours for heat treatment to prepare the first-stage oxidation state catalyst A. Carrying out vulcanization treatment on the first-stage oxidation state catalyst A by adopting an in-situ vulcanization process, introducing dimethyl disulfide with the amount being 120% of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain a first-stage vulcanization catalyst A; putting a section of the sulfidation catalyst A into a rolling pot, spraying 80mL of an ammonia water solution containing 7.5 percent of molybdenum trioxide and 25 percent of molybdenum trioxide into an alumina carrier in an atomization mode under the rotation condition, continuously rotating the rolling pot for 30 minutes after the solution is sprayed, and drying the rolling pot for 4 hours at the temperature of 110 ℃ to obtain a finished product sulfide-oxide composite catalyst A.

Example 2

Dissolving 9.4g of citric acid in 95mL of purified water, adding 7.0g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 8.3g of ammonium molybdate into the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of carrier is placed in a rolling pot, spraying and soaking are carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at 110 ℃, then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and roasted for 3 hours, then the carrier is placed in 600mL of hexadiene solvent for soaking for 4 hours, then the carrier is heated to 200 ℃ for 4 hours, then the carrier is heated to 300 ℃ for 24 hours, and then the carrier is heated to 400 ℃ for 10 hours for heat treatment to prepare the first-stage oxidation state catalyst B. Carrying out vulcanization treatment on the first-stage oxidation state catalyst B by adopting an in-situ vulcanization process, introducing dimethyl disulfide with the amount being 120% of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain a first-stage vulcanization catalyst B; putting a section of the sulfidation catalyst B into a rolling pot, spraying 90mL of an ammonia water solution containing 3.4 percent of molybdenum trioxide and 25 percent of molybdenum oxide into the alumina carrier in an atomizing mode under the rotating condition, continuously rotating the rolling pot for 30 minutes after the solution is sprayed, and drying the solution for 4 hours at 110 ℃ to obtain a finished product sulfide-oxide composite catalyst B.

Example 3

Dissolving 21.7g of citric acid in 65mL of purified water, adding 16.1g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent by weight of ammonia water to 135mL, adding 21.0g of ammonium molybdate to the solution, adjusting the volume of the solution to 150mL by using 25 percent ammonia water after dissolving, and sealing for storage. 200g of carrier is placed in a rolling pot, spraying and soaking are carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at 110 ℃, then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and roasted for 3 hours, then the carrier is placed in 600mL of hexadiene solvent for soaking for 4 hours, then the carrier is heated to 200 ℃ for 4 hours, then the carrier is heated to 300 ℃ for 24 hours, and then the carrier is heated to 400 ℃ for 10 hours for heat treatment to prepare the first-stage oxidation state catalyst C. Carrying out vulcanization treatment on the first-stage oxidation state catalyst C by adopting an in-situ vulcanization process, introducing dimethyl disulfide with the amount of 120% of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain a first-stage vulcanization catalyst C; putting a section of the sulfidation catalyst C into a rolling pot, spraying 76mL of an ammonia water solution with the weight of 25 percent into 12.1g of molybdenum trioxide by atomization mode on an alumina carrier in the rolling pot under the rotation condition, continuously rotating the rolling pot for 30 minutes after the solution is sprayed, and drying the rolling pot for 4 hours at the temperature of 110 ℃ to obtain a finished product sulfide-oxide composite catalyst C.

Example 4

Dissolving 25.9g of citric acid in 30mL of purified water, adding 19.3g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 31.2g of ammonium molybdate to the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of carrier is placed in a rolling pot, spraying and soaking are carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at 110 ℃, then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and roasted for 3 hours, then the carrier is placed in 600mL of hexadiene solvent for soaking for 4 hours, then the carrier is heated to 200 ℃ for 4 hours, then the carrier is heated to 300 ℃ for 24 hours, and then the carrier is heated to 400 ℃ for 10 hours for heat treatment to prepare the first-stage oxidation state catalyst D. Carrying out vulcanization treatment on the first-stage oxidation state catalyst D by adopting an in-situ vulcanization process, introducing dimethyl disulfide with the amount being 120% of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain a first-stage vulcanization catalyst D; putting a section of the sulfidation catalyst D into a rolling pot, spraying 76mL of ammonia water solution containing 14.1g of molybdenum trioxide and 25 percent by weight into the alumina carrier in an atomizing mode under the rotating condition, continuously rotating the rolling pot for 30 minutes after the solution is sprayed, and drying the rolling pot for 4 hours at 110 ℃ to obtain the finished product sulfide-oxide composite catalyst D.

Example 5

On a 200mL small-sized hydrogenation device of a fixed bed, A, B, C, D catalysts are respectively adopted, the reaction pressure is 1.6MPa, and the liquid hourly space velocity is 3.0h^-1Hydrogen/oil volume ratio of 300 Nm³/ m³The reaction temperatures were 270 and 310, respectivelyAnd carrying out selective hydrodesulfurization on the raw material with the sulfur content of 664 mu g/g and the RON of 93.0 at the temperature of 260 ℃ and 250 ℃.

Comparative example 1

Dissolving 16.8g of citric acid in 90mL of purified water, adding 12.5g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 20.8g of ammonium molybdate into the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of alumina carrier modified by carbon and silicon oxide according to a specific ratio is placed in a rolling pot, spraying and soaking are carried out by 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the rolling pot is rotated for 30 minutes, then the rolling pot is placed for 18 hours, drying is carried out for 3 hours at 110 ℃, then the temperature is raised to 500 ℃ at the temperature raising speed of 200 ℃/hour, and the semi-finished catalyst E is prepared after roasting is carried out for 3 hours. And (3) carrying out vulcanization treatment on the semi-finished product catalyst E by adopting an in-situ vulcanization process, introducing 120% of dimethyl disulfide of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain the finished product catalyst E.

Comparative example 2

Dissolving 9.4g of citric acid in 95mL of purified water, adding 6.0g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 11.7g of ammonium molybdate into the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of alumina carrier modified by carbon and silicon oxide according to a specific ratio is placed in a rolling pot, spraying and soaking are carried out by 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the rolling pot is rotated for 30 minutes, then the rolling pot is placed for 18 hours, drying is carried out for 3 hours at 110 ℃, then the temperature is raised to 500 ℃ at the temperature raising speed of 200 ℃/hour, and the semi-finished catalyst F is prepared after roasting is carried out for 3 hours. And (3) carrying out vulcanization treatment on the semi-finished product catalyst F by adopting an in-situ vulcanization process, introducing 120% of dimethyl disulfide of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain the finished product catalyst F.

Comparative example 3

Dissolving 21.7g of citric acid in 65mL of purified water, adding 16.1g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent by weight of ammonia water to 135mL, adding 33.1g of ammonium molybdate to the solution, adjusting the volume of the solution to 150mL by using 25 percent ammonia water after dissolving, and sealing for storage. 200G of carrier is placed in a rolling pot, spraying and soaking is carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at the temperature of 110 ℃, and then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and is roasted for 3 hours, thus obtaining the semi-finished catalyst G. And (3) carrying out vulcanization treatment on the semi-finished product catalyst G by adopting an in-situ vulcanization process, introducing dimethyl disulfide accounting for 120% of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain the finished product catalyst G.

Comparative example 4

Dissolving 25.9g of citric acid in 40mL of purified water, adding 19.3g of cobalt carbonate, boiling for dissolving, cooling, adding 25 percent (by weight) of ammonia water to 130mL, adding 45.3g of ammonium molybdate to the solution, adjusting the volume of the solution to 150mL by using 25 percent of ammonia water after dissolving, and sealing for storage. 200g of carrier is placed in a rolling pot, spraying and soaking is carried out by using 150mL of prepared molybdenum and cobalt ammonia solution, after the solution is sprayed, the carrier continues to rotate in the rolling pot for 30 minutes, then the carrier is placed for 18 hours, the carrier is dried for 3 hours at the temperature of 110 ℃, and then the carrier is heated to 500 ℃ at the heating rate of 200 ℃/hour and is roasted for 3 hours, thus obtaining the semi-finished catalyst H. And (3) carrying out vulcanization treatment on the semi-finished product catalyst H by adopting an in-situ vulcanization process, introducing 120% of dimethyl disulfide of the theoretical sulfur demand of the catalyst, and carrying out temperature programming in the vulcanization process, wherein the temperature is raised to 280 ℃ and is kept constant for 10 hours to obtain the finished product catalyst H.

Comparative example 5

Catalysts E, F, G and H were evaluated separately in the same manner as in example 5.

Example 6

The results of comparing the physical and chemical properties of the catalysts prepared in the above examples with those of the catalysts prepared in the above examples, which were operated in a small-sized hydrogenation apparatus for 600 hours, are shown in tables 1 and 2.

A. B, C, D before the catalyst is used, the sulfurization process in the reactor is carried out, the amount of introduced dimethyl disulfide is 120% of the theoretical sulfur demand of the catalyst, the sulfurization process adopts temperature programming, the temperature is raised to 280 ℃ and the temperature is kept for 10 h.

TABLE 1 catalyst key Properties

TABLE 1 (continuation) catalyst essential Properties

TABLE 2 catalyst Activity and Selectivity

Reaction conditions are as follows: p =1.6MPa, LHSV =3.0h^-1；H₂/Oil=300Nm³/ m³。

The results in Table 2 show that the catalyst of the invention has better hydrodesulfurization selectivity and has smaller octane number loss under the condition of the same desulfurization rate. After a certain running time, the selective hydrodesulfurization performance of the catalyst is more stable than that of a comparative catalyst.