A hydrodesulfurization catalyst, its preparation method and application

Abstract

The present invention discloses a hydrodesulfurization catalyst, a preparation method thereof and an application thereof. In the method of the present invention, raw alumina is mixed and treated with distilled water, dried, then mixed with an alcohol substance, dried again and treated at a high temperature. After that, it is mixed with aluminum nitrate and distilled water, then directly filtered, and then filtered and washed with a mixture of acetic acid and distilled water and heat-treated to obtain modified alumina. Then, a molybdenum source is made into a molybdenum-containing impregnating solution, and the obtained modified alumina is impregnated and heat-treated to obtain the hydrodesulfurization catalyst. The alkali amount of the modified alumina in the catalyst is reduced by less than 1% compared with the alkali amount of the raw alumina. The hydrodesulfurization catalyst provided by the present invention has a high active metal utilization rate. When used in the hydrodesulfurization process of petroleum hydrocarbons, sulfur-containing compounds in the oil product can be removed, and the hydrodesulfurization efficiency of the catalyst can be improved. It is a high-efficiency and low-cost hydrodesulfurization catalyst.

Description

Technical Field

[0001] The present invention belongs to the field of synthesis of catalytic materials, and particularly relates to a hydrodesulfurization catalyst, a preparation method thereof and an application thereof. Background Art

[0002] With the progress of technology, hydrocatalysts play an increasingly important role in the petroleum refining process. However, it is becoming more and more difficult to improve the performance of hydrocatalysts, and researchers have been constantly trying various methods to improve the performance of catalysts.

[0003] CN109718820A discloses a phosphorus-modified composite hydrodesulfurization catalyst. The catalyst is composed of nickel molybdenum tungsten sulfide and phosphorus-modified clay, with nickel molybdenum tungsten as the desulfurization active component and phosphorus-modified clay as the carrier. Through adsorption, ion exchange, impregnation, drying, extrusion molding, and then calcination and presulfurization treatment, nickel molybdenum tungsten is uniformly dispersed in the structure of phosphorus-modified clay to form a phosphorus-modified composite hydrodesulfurization catalyst, which is suitable for deep desulfurization of sulfur in oil products. However, the catalytic performance of this catalyst still needs to be further improved to meet more stringent reaction requirements.

[0004] CN105107521A discloses an Mn-Fe bimetal-doped activated carbon-based desulfurization catalyst and a preparation method thereof. The catalyst uses activated carbon modified by nitric acid as the carrier and metals Mn and Fe as the active components. The active components are loaded on the carrier through impregnation and high-temperature calcination in a nitrogen atmosphere. The specific preparation method is to first immerse the activated carbon in nitric acid for modification, and then immerse the modified activated carbon in a mixed solution of manganese nitrate solution and iron nitrate solution to load the active components Mn and Fe on the modified activated carbon carrier. Then, the modified activated carbon loaded with Mn and Fe is calcined to obtain the desulfurization catalyst. However, its application range is relatively narrow and is limited in petroleum refining.

[0005] CN108101081A discloses a preparation method of modified alumina. The preparation method is as follows: mix alumina with deionized water, stir, and dry; then mix with ethanol, stir, and dry, and then treat at a certain temperature; then mix with an auxiliary agent and deionized water, stir, and then directly separate and dry and perform high-temperature treatment; then mix with the auxiliary agent and deionized water again, stir, and then directly separate and dry and perform high-temperature treatment to obtain the modified alumina product. Although the alumina provided by this method has the characteristic of adjustable alkalinity, this method will introduce some other ions, which will reduce the catalytic activity when using this alumina as a catalyst. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a hydrodesulfurization catalyst, a preparation method thereof, and an application thereof. The hydrodesulfurization catalyst provided by the present invention has a high utilization rate of active metals. When used in the hydrodesulfurization process of petroleum hydrocarbons, it can remove sulfur-containing compounds in oil products, improve the hydrodesulfurization efficiency of the catalyst, and is an efficient and low-cost hydrodesulfurization catalyst.

[0007] In the first aspect of the present invention, a hydrodesulfurization catalyst is provided, which includes a carrier and molybdenum oxide. The carrier is a modified alumina obtained by modifying raw alumina, and the alkali content of the modified alumina is reduced by less than 1%, preferably 0.9% - 0.5%, compared with the alkali content of the raw alumina (i.e., the alumina before modification).

[0008] In the present invention, the alumina in the modified alumina is γ-alumina.

[0009] In the present invention, based on the weight of the catalyst, the content of molybdenum oxide is 4% - 24%, preferably 5.7% - 23%; the content of the carrier is 76% - 96%, preferably 77% - 94.3%.

[0010] In the present invention, the specific surface area of the catalyst is 200 - 350 m 2 / g, the pore volume is 0.2 - 0.55 cm 3 / g, and the total acid amount is 0.3 - 1.2 mmol / g.

[0011] In the present invention, in the catalyst, the size of molybdenum oxide metal particles is about 0.5 - 1.3 nm.

[0012] In the second aspect of the present invention, a preparation method of the above-mentioned hydrodesulfurization catalyst is provided, which includes the following steps:

[0013] (a) Mix raw alumina with distilled water, and dry at 90 - 220 °C for 9 - 24 h, preferably dry at 100 - 200 °C for 10 - 20 h;

[0014] (b) Mix the solid obtained in step (a) with an alcohol substance, then dry at 90 - 220 °C for 9 - 24 h, preferably dry at 100 - 200 °C for 10 - 20 h, and then perform high-temperature treatment at 280 - 410 °C for 1 - 6 h, preferably perform high-temperature treatment at 300 - 400 °C for 2 - 5 h;

[0015] (c) Mix the solid obtained in step (b) with aluminum nitrate and distilled water, and then directly filter;

[0016] (d) Wash and filter the solid obtained in step (c) with a mixture of acetic acid and distilled water;

[0017] (e) Treat the solid obtained in step (d) at 80 - 150 °C for 1 - 12 h, preferably at 100 - 140 °C for 2 - 10 h, to obtain modified alumina;

[0018] (f) Prepare a molybdenum-containing impregnation solution from a molybdenum source, then impregnate the modified alumina obtained in step (e), and after high-temperature treatment, obtain the hydrodesulfurization catalyst.

[0019] In the method of the present invention, the alumina described in step (a) is γ-alumina, and the γ-alumina can be self-made or commercially available.

[0020] In the method of the present invention, the mass ratio of the original alumina to distilled water described in step (a) is 0.5 - 5:10, preferably 1 - 4:10.

[0021] In the method of the present invention, the alcohols described in step (b) are at least one of pure (analytical pure) ethanol or propanol.

[0022] In the method of the present invention, the mass ratio of the solid to alcohols described in step (b) is 0.5 - 5:10, preferably 1 - 4:10.

[0023] In the method of the present invention, the mass ratio of the solid, aluminum nitrate, and distilled water described in step (c) is 0.9 - 12:0.9 - 24:100, preferably 1 - 10:1 - 20:100.

[0024] In the method of the present invention, the direct separation described in step (c) means that it cannot be washed with water or other solvents, and only the mixture needs to be directly filtered and separated.

[0025] In the method of the present invention, the mass ratio of the solid, acetic acid, and distilled water described in step (d) is 0.9 - 12:18 - 65:1000, preferably 1 - 10:20 - 60:1000.

[0026] In the method of the present invention, the temperature of the acetic acid and distilled water mixture described in step (d) should be maintained at 70 - 95 °C, preferably 80 - 90 °C.

[0027] In the method of the present invention, the molybdenum source described in step (f) includes at least one of ammonium heptamolybdate, ammonium dimolybdate, ammonium tetramolybdate, and ammonium octamolybdate.

[0028] In the method of the present invention, in the molybdenum-containing impregnation solution described in step (f), the mass concentration of molybdenum in the form of MoO3 is 5% - 32%, preferably 6% - 30%.

[0029] In the method of the present invention, the impregnation described in step (f) adopts the isovolumetric saturation impregnation method, and the amount of the solution is determined by the traditional isovolumetric saturation impregnation method.

[0030] In the method of the present invention, in step (f), the high-temperature treatment temperature is 400 to 650 °C, preferably 450 to 600 °C; the treatment time is 2 to 10 h, preferably 3 to 8 h.

[0031] The third aspect of the present invention provides the application of the above hydrodesulfurization catalyst in the process of removing sulfur compounds in oil products.

[0032] The hydrodesulfurization catalyst of the present invention needs to be sulfided before use. The sulfidation can adopt any one of the existing sulfidation methods in the art.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) Compared with the existing catalysts, the catalyst provided by the method of the present invention has better catalytic performance. For the active metal molybdenum, the basic sites of alumina are not ideal loading sites for molybdenum metal. The molybdenum metal loaded on the basic sites almost loses its catalytic activity. Therefore, this part of molybdenum metal can hardly play a catalytic role in the actual catalytic process, resulting in the waste of molybdenum metal and the reduction of the overall utilization rate of molybdenum metal. However, the method of the present invention can make aluminum nitrate and acetic acid occupy the basic sites of alumina in a certain complex form, prompting the active metal molybdenum to be loaded on the non-basic sites of alumina. In this way, the catalytic performance of most molybdenum metal can be fully exerted, the utilization rate of the active metal molybdenum is improved, the proportion of ineffective molybdenum metal in the catalyst is greatly reduced, especially the catalytic performance of the low-metal-content catalyst can be improved, and the low-metal-content catalyst has higher hydrodesulfurization activity, thus improving the catalytic efficiency of the catalyst.

[0035] (2) The size of the molybdenum oxide metal particles of the catalyst prepared by the method of the present invention is larger than that of the molybdenum oxide of the catalyst prepared by the conventional method under the same conditions, and the hydrodesulfurization activity of the catalyst is higher. Description of the Drawings

[0036] Figure 1 TEM photograph of the catalyst sample prepared in Example 1;

[0037] Figure 2 TEM photograph of the catalyst sample prepared in Comparative Example 3. Detailed Embodiments

[0038] The pore structure of the catalyst provided by the present invention is measured by N2 adsorption-desorption. Before the measurement, the sample is vacuum-treated at 300 °C for more than 4 h. The total specific surface area and other parameters are calculated according to the BET isotherm equation.

[0039] The basicity of the alumina provided by the present invention is characterized by the carbon dioxide temperature-programmed desorption (CO2-TPD) method. The specific characterization process is as follows: The sample is treated at 300 °C for 1 h in a helium atmosphere at 30 mL / min; then cooled to 70 °C and treated for 2 h in a CO2-He (5% CO2 and 95% He) atmosphere at 30 mL / min; then treated at 70 °C for 1 h in a He atmosphere at 30 mL / min; finally, the CO2-TPD characterization of the sample is carried out at a rate of 10 °C / min in a He atmosphere at 10 mL / min. The calculation of the basicity uses the peak area integration method. Taking the basicity of the original alumina as 100%, the ratio of the basicity of the test sample to that of the original alumina is used as the basicity of the test sample.

[0040] The acidic properties of the catalyst provided by the present invention are measured by ammonia-TPD. The sample is pretreated in a helium atmosphere at 500 °C for 1 h, adsorbed with ammonia until saturation at 150 °C, and the temperature is raised to 550 °C at a heating rate of 10 °C / min to obtain the NH3-TPD spectrum of the sample.

[0041] The microstructure of the catalyst provided by the present invention is characterized by a high-resolution electron microscope. The JEM-2100LaB6 high-resolution transmission electron microscope of JEOL Company, Japan is used for sample morphology observation and electron diffraction analysis, and the 832CCD camera of Gatan Company, USA is used to collect images and electron diffraction spectra.

[0042] The present invention will be further described below through examples, but the protection scope of the present invention is not limited by the examples.

[0043] The original alumina raw materials used in the following examples and comparative examples are all γ-alumina. The specific surface area of γ-alumina is 286 m 2 / g, the pore volume is 0.36 cm 3 / g, and the total acid amount is 0.57 mmol / g.

[0044] Example 1

[0045] First, take 18.8 g of alumina and mix it evenly with 100 g of distilled water. After filtration, it is dried at 110 °C for 15 h; then mixed evenly with 100 g of ethanol, filtered, and dried at 120 °C for 15 h. Then it is treated at 351 °C for 5 h; then take 8 g of the solid from the previous step and mix it evenly with 16 g of aluminum nitrate and 100 g of distilled water, and then filter; then wash the solid substance with a mixed solution of 50 g of acetic acid and 1000 g of distilled water (85 °C); then treat it at 130 °C for 10 h to obtain the modified alumina S-1. After measurement, taking the basicity of the original alumina as 100%, the basicity of the prepared modified alumina S-1 is 0.6%.

[0046] 12.3 g of ammonium heptamolybdate and 100 g of distilled water were mixed evenly; then, 10 g of the modified alumina prepared in the previous step was mixed evenly with 9.3 g of molybdenum metal solution (measured by equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, it was treated at 560 °C for 7 h to obtain catalyst sample A.

[0047] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst A is 278 m 2 / g, and the pore volume is 0.35 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.56 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 1.09 nm.

[0048] Example 2

[0049] First, 10 g of alumina and 100 g of distilled water were mixed evenly, filtered and dried at 120 °C for 8 h; then it was mixed evenly with 100 g of ethanol, filtered and dried at 120 °C for 10 h, and then treated at 300 °C for 2 h; then, 1 g of the solid in the previous step was mixed evenly with 1 g of aluminum nitrate and 100 g of distilled water, and then filtered; then the solid material was washed with a mixed solution of 20 g of acetic acid and 1000 g of distilled water (80 °C); then it was treated at 100 °C for 10 h to obtain modified alumina S-2. It was measured that, taking the alkali amount of the original alumina as 100%, the basicity of the prepared modified alumina S-2 was 0.9%.

[0050] 6.0 g of ammonium heptamolybdate and 100 g of distilled water were mixed evenly; then, 10 g of the modified alumina prepared in the previous step was mixed evenly with 9.3 g of molybdenum metal solution (measured by equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, it was treated at 450 °C for 8 h to obtain catalyst sample B.

[0051] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst B is 290 m 2 / g, and the pore volume is 0.37 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.51 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.59 nm.

[0052] Example 3

[0053] First, take 40 g of alumina and 100 g of distilled water, mix them evenly, filter, and then dry at 200 °C for 20 h; then mix evenly with 100 g of ethanol, filter, and dry at 200 °C for 20 h, and then treat at 400 °C for 5 h; then take 10 g of the solid from the previous step, mix evenly with 20 g of aluminum nitrate and 100 g of distilled water, and then filter; then wash the solid substance with a mixed solution of 60 g of acetic acid and 1000 g of distilled water (90 °C); then treat at 140 °C for 2 h to obtain modified alumina S-3. After measurement, based on the alkali amount of the original alumina being 100%, the alkalinity of the prepared modified alumina S-3 is 0.8%.

[0054] Take 30.0 g of ammonium heptamolybdate and 100 g of distilled water, mix them evenly; then take 10 g of the modified alumina prepared in the previous step and mix evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat at 600 °C for 3 h to obtain catalyst sample C.

[0055] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst C is 263 m 2 / g, and the pore volume is 0.31 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.67 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 1.25 nm.

[0056] Example 4

[0057] First, take 31.4 g of alumina and 95 g of distilled water, mix them evenly, filter, and then dry at 125 °C for 11 h; then mix evenly with 100 g of ethanol, filter, and dry at 137 °C for 16 h, and then treat at 350 °C for 4.5 h; then take 7.6 g of the solid from the previous step, mix evenly with 13.5 g of aluminum nitrate and 100 g of distilled water, and then filter; then wash the solid substance with a mixed solution of 51.4 g of acetic acid and 1000 g of distilled water (88 °C); then treat at 125 °C for 10 h to obtain modified alumina S-4. After measurement, based on the alkali amount of the original alumina being 100%, the alkalinity of the prepared modified alumina S-4 is 0.7%.

[0058] Take 15.6 g of ammonium heptamolybdate and 100 g of distilled water, mix them evenly; then take 10 g of the modified alumina prepared in the previous step and mix evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat at 550 °C for 5.5 h to obtain catalyst sample D.

[0059] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst D is 266 m 2 / g, and the pore volume is 0.38 cm 3 / g; Based on ammonia-TPD analysis, the total acid amount is 0.55 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 1.16 nm.

[0060] Example 5

[0061] First, take 16.8 g of alumina and 110 g of distilled water, mix them evenly, filter and dry at 160 °C for 18 h; then mix evenly with 100 g of ethanol, filter and dry at 155 °C for 20 h, and then treat at 380 °C for 3 h; then take 5.5 g of the solid from the previous step, mix evenly with 11 g of aluminum nitrate and 100 g of distilled water, and then filter; then wash the solid material with a mixed solution of 32 g of acetic acid and 1000 g of distilled water (82 °C); then treat at 140 °C for 10 h to obtain modified alumina S-5. After measurement, taking the alkali amount of the original alumina as 100%, the basicity of the prepared modified alumina S-5 is 0.8%.

[0062] Take 20.1 g of ammonium heptamolybdate and 100 g of distilled water, mix them evenly; then take 10 g of the modified alumina prepared in the previous step and mix evenly with 9.3 g of molybdenum metal solution (measured by equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat at 520 °C for 4 h to obtain catalyst sample E.

[0063] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst E is 258 m 2 / g, the pore volume is 0.35 cm 3 / g; Based on ammonia-TPD analysis, the total acid amount is 0.45 mol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 1.22 nm.

[0064] Example 6

[0065] Press and form the catalyst prepared in Example 1, crush it, and then select 10 mL of the catalyst with a particle size of 20-60 mesh and load it into the reactor. Then introduce 15 mL / h of n-octane containing 5% (by weight) carbon disulfide, and introduce 150 mL / min of hydrogen, maintain the system pressure at 3 MPa, the system temperature at 320 °C, and the treatment time at 4 h to sulfide the catalyst. Then introduce 15 mL / h of n-nonane containing 300 ppm (by weight) thiophene, and introduce 150 mL / min of hydrogen, maintain the system pressure at 3.5 MPa, the system temperature at 300 °C, and select the liquid product from the 4th h to the 5th h of the reaction time for sulfur content analysis. The measurement result shows that the sulfur content of the liquid product after hydrodesulfurization is 33 ppm (by weight).

[0066] Example 7

[0067] Comparative Example 6, the difference is that the catalyst prepared in Example 1 is replaced with the catalyst prepared in Example 2, and the measurement result shows that the sulfur content of the liquid product after hydrodesulfurization is 68 ppm (by weight).

[0068] Example 8

[0069] Comparative Example 6, the difference is that the catalyst prepared in Example 1 is replaced with the catalyst prepared in Example 3, and the measurement result shows that the sulfur content of the liquid product after hydrodesulfurization is 17 ppm (by weight).

[0070] Example 9

[0071] Comparative Example 6, the difference is that the catalyst prepared in Example 1 is replaced with the catalyst prepared in Example 4, and the measurement result shows that the sulfur content of the liquid product after hydrodesulfurization is 25 ppm (by weight).

[0072] Example 10

[0073] Comparative Example 6, the difference is that the catalyst prepared in Example 1 is replaced with the catalyst prepared in Example 5, and the measurement result shows that the sulfur content of the liquid product after hydrodesulfurization is 22 ppm (by weight).

[0074] Comparative Example 1

[0075] First, take 18.8 g of alumina and 100 g of distilled water, mix them evenly, filter and dry at 110 °C for 15 h; then mix evenly with 100 mL of ethanol, filter and dry at 120 °C for 15 h, and then treat at 351 °C for 5 h; then take 8 g of the solid obtained in the previous step and mix evenly with 16 g of aluminum nitrate and 100 g of distilled water; then treat at 130 °C for 10 h to obtain modified alumina S-6. After measurement, based on the alkali amount of the original alumina being 100%, the alkalinity of the prepared modified alumina S-6 is 68%.

[0076] Take 12.3 g of ammonium heptamolybdate and 100 g of distilled water, mix them evenly; then take 10 g of the modified alumina prepared in the previous step and mix evenly with 9.3 g of molybdenum metal solution (measured by equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat at 560 °C for 7 h to obtain catalyst sample F.

[0077] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst F is 255 m 2 / g, and the pore volume is 0.39 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.68 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.78 nm.

[0078] Comparative Example 2

[0079] First, take 18.8 g of alumina and mix it evenly with 100 g of distilled water. After filtration, dry it at 110 °C for 15 h; then mix it evenly with 100 mL of ethanol, filter it, and dry it at 120 °C for 15 h. Then, treat it at 351 °C for 5 h; then wash the solid material with a mixed solution of 50 g of acetic acid and 1000 g of distilled water (85 °C); then treat it at 130 °C for 10 h to obtain modified alumina S-7. After measurement, based on the alkali content of the original alumina being 100%, the alkalinity of the prepared modified alumina S-7 is 57%.

[0080] Take 12.3 g of ammonium heptamolybdate and mix it evenly with 100 g of distilled water; then take 10 g of the modified alumina prepared in the previous step and mix it evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat it at 560 °C for 7 h to obtain catalyst sample G.

[0081] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst G is 267 m 2 / g, and the pore volume is 0.40 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.61 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.75 nm.

[0082] Comparative Example 3

[0083] First, take 18.8 g of alumina and mix it evenly with 100 g of distilled water. After filtration, dry it at 110 °C for 15 h; then mix it evenly with 100 mL of ethanol, filter it, and dry it at 120 °C for 15 h. Then, treat it at 351 °C for 5 h to obtain modified alumina S-8. After measurement, based on the alkali content of the original alumina being 100%, the alkalinity of the prepared modified alumina S-8 is 100%.

[0084] Then, take 12.3 g of ammonium heptamolybdate and mix it evenly with 100 g of distilled water; then take 10 g of the modified alumina prepared in the previous step and mix it evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat it at 560 °C for 7 h to obtain catalyst sample H.

[0085] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst H is 274 m 2 / g, and the pore volume is 0.45 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.68 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.66 nm.

[0086] Comparative Example 4

[0087] First, take 18.8 g of alumina and mix it evenly with 100 g of distilled water. After filtration, dry it at 110 °C for 15 h. Then mix it evenly with 100 g of ethanol, filter it, and dry it at 120 °C for 15 h. Then treat it at 351 °C for 5 h. Then take 8 g of the solid obtained in the previous step and mix it evenly with 16 g of acetic acid, 16 g of aluminum nitrate, and 100 g of distilled water, and then filter it. Then treat it at 130 °C for 10 h to obtain modified alumina S-9. After measurement, taking the alkali amount of the original alumina as 100%, the alkalinity of the prepared modified alumina S-9 is 55%.

[0088] Take 12.3 g of ammonium heptamolybdate and mix it evenly with 100 g of distilled water. Then take 10 g of the modified alumina prepared in the previous step and mix it evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina). Finally, treat it at 560 °C for 7 h to obtain catalyst sample I.

[0089] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst I is 264 m 2 / g, and the pore volume is 0.35 cm 3 / g; based on ammonia-TPD analysis, the total acid amount is 0.54 mmol / g; based on transmission electron microscopy analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.65 nm.

[0090] Comparative Example 5

[0091] First, take 18.8 g of alumina and mix it evenly with 100 g of distilled water. After filtration, dry it at 110 °C for 15 h. Then mix it evenly with 100 g of ethanol, filter it, and dry it at 120 °C for 15 h. Then treat it at 351 °C for 5 h. Then wash the solid material with a mixture of 8 g of the solid obtained in the previous step and 50 g of acetic acid and 1000 g of distilled water (85 °C). Then mix it evenly with 16 g of aluminum nitrate and 100 g of distilled water, and then filter it. Then treat it at 130 °C for 10 h to obtain modified alumina S-10. After measurement, taking the alkali amount of the original alumina as 100%, the alkalinity of the prepared modified alumina S-10 is 56%.

[0092] Take 12.3 g of ammonium heptamolybdate and mix it evenly with 100 g of distilled water. Then take 10 g of the modified alumina prepared in the previous step and mix it evenly with 9.3 g of molybdenum metal solution (measured by the equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina). Finally, treat it at 560 °C for 7 h to obtain catalyst sample J.

[0093] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst J is 274 m 2 / g, and the pore volume is 0.39 cm 3 / g; Based on ammonia-TPD analysis, the total acid amount is 0.51 mmol / g; based on transmission electron microscope analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.67 nm.

[0094] Comparative Example 6

[0095] Treat alumina according to the method provided in CN108101081A, and then prepare the catalyst.

[0096] First, take 18.8 g of alumina and 70 g of distilled water, stir for 30 min to mix evenly, and then dry at 110 °C for 15 h; then stir with 70 g of ethanol for 30 min to mix evenly, filter and dry at 120 °C for 15 h, then treat at 235 °C for 5 h; then stir with 3.8 g of aluminum chloride and 100 g of distilled water for 8 h to mix evenly, and then directly filter and separate; then treat at 150 °C for 15 h, then treat at 600 °C for 6 h in a nitrogen atmosphere, and then mix and stir the alumina treated in the nitrogen atmosphere with 3 g of aluminum chloride and 100 mL of distilled water for 8 h, then directly filter and separate, then dry at 150 °C for 15 h, and then treat the obtained substance at 600 °C for 6 h in a nitrogen atmosphere to obtain modified alumina S-11. After measurement, taking the alkali amount of the original alumina as 100%, the basicity of the prepared modified alumina S-11 is 1.8%.

[0097] Take 12.3 g of ammonium heptamolybdate and 100 g of distilled water and mix evenly; then take 10 g of the modified alumina prepared in the previous step and mix evenly with 9.3 g of molybdenum metal solution (measured by equal-volume saturation impregnation method as 0.93 g of water / 1 g of alumina); finally, treat at 560 °C for 7 h to obtain catalyst sample K.

[0098] Based on N2 adsorption-desorption analysis, the specific surface area of the catalyst K is 270 m 2 / g, and the pore volume is 0.39 cm 3 / g; Based on ammonia-TPD analysis, the total acid amount is 0.57 mmol / g; based on transmission electron microscope analysis, the size of the molybdenum oxide metal particles of the catalyst is about 0.64 nm.

[0099] Comparative Example 7

[0100] The catalyst obtained in Comparative Example 1 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product from the 4th h to the 5th h of the reaction time was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 129 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalyst prepared by the method of the present invention has more excellent catalytic performance.

[0101] Comparative Example 8

[0102] The catalyst obtained in Comparative Example 2 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product from the 4th h to the 5th h of the reaction time was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 128 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalyst prepared by the method of the present invention has more excellent catalytic performance.

[0103] Comparative Example 9

[0104] The catalyst obtained in Comparative Example 3 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product in the reaction time from the 4th h to the 5th h was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 132 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalytic performance of the catalyst prepared by the method of the present invention is more excellent.

[0105] Comparative Example 10

[0106] The catalyst obtained in Comparative Example 4 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product in the reaction time from the 4th h to the 5th h was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 155 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalytic performance of the catalyst prepared by the method of the present invention is more excellent.

[0107] Comparative Example 11

[0108] The catalyst obtained in Comparative Example 5 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product from the 4th h to the 5th h of the reaction time was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 142 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalyst prepared by the method of the present invention has more excellent catalytic performance.

[0109] Comparative Example 12

[0110] The catalyst obtained in Comparative Example 6 was tableted, formed, and pulverized. 10 mL of the catalyst with a particle size of 20 - 60 mesh was charged into a microreactor. Then, n - octane containing 5% (by weight) carbon disulfide at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3 MPa, the system temperature was 320 °C, and the treatment time was 4 h to sulfide the catalyst. Then, n - nonane containing 300 ppm (by weight) thiophene at a flow rate of 15 mL / h was introduced, and hydrogen at a flow rate of 150 mL / min was introduced. The system pressure was maintained at 3.5 MPa, the system temperature was 300 °C, and the liquid product from the 4th h to the 5th h of the reaction time was taken for sulfur content analysis. The measurement result showed that the sulfur content of the liquid product after hydrodesulfurization was 147 ppm (by weight), and the desulfurization rate was much lower than that of Example 6 (with the same catalyst metal content and reaction conditions). This indicates that the catalyst prepared by the method of the present invention has more excellent catalytic performance.

Claims

1. Use of a hydrodesulfurization catalyst in the process of removing sulfur-containing compounds from oil products, characterized in that, The catalyst comprises a support and molybdenum oxide. The support is modified alumina obtained by modifying raw alumina, and the alkali content of the modified alumina is reduced by 0.8% - 0.5% compared with that of the raw alumina. In the catalyst, the size of the molybdenum oxide metal particles is 1.09 - 1.3 nm. The preparation method of the hydrodesulfurization catalyst comprises the following steps: (a) Mix the raw alumina with distilled water and treat it, and dry it at 90 - 220 °C for 9 - 24 h; (b) Mix the solid obtained in step (a) with an alcohol substance, dry it at 90 - 220 °C for 9 - 24 h, and then perform high-temperature treatment at 280 - 410 °C for 1 - 6 h; (c) Mix the solid obtained in step (b) with aluminum nitrate and distilled water, and then directly filter; (d) Wash and filter the solid obtained in step (c) with a mixture of acetic acid and distilled water; (e) Treat the solid obtained in step (d) at 80 - 150 °C for 1 - 12 h to obtain modified alumina; (f) Prepare a molybdenum-containing impregnation solution from a molybdenum source, and then impregnate the modified alumina obtained in step (e), and perform high-temperature treatment at 400 - 650 °C to obtain the hydrodesulfurization catalyst; In step (c), the mass ratio of the solid, aluminum nitrate, and distilled water is 0.9 - 12:0.9 - 24:100; in step (d), the mass ratio of the solid, acetic acid, and distilled water is 0.9 - 12:18 - 65:1000.

2. The application according to claim 1, wherein The preparation method of the hydrodesulfurization catalyst comprises the following steps: (a) Mix the raw alumina with distilled water and treat it, and dry it at 100 - 200 °C for 10 - 20 h; (b) Mix the solid obtained in step (a) with an alcohol substance, dry it at 100 - 200 °C for 10 - 20 h, and then perform high-temperature treatment at 300 - 400 °C for 2 - 5 h; (c) Mix the solid obtained in step (b) with aluminum nitrate and distilled water, and then directly filter; (d) Wash and filter the solid obtained in step (c) with a mixture of acetic acid and distilled water; (e) Treat the solid obtained in step (d) at 100 - 140 °C for 2 - 10 h to obtain modified alumina; (f) Prepare a molybdenum-containing impregnation solution from a molybdenum source, and then impregnate the modified alumina obtained in step (e), and perform high-temperature treatment at 450 - 600 °C to obtain the hydrodesulfurization catalyst.

3. The application according to claim 1, wherein The alumina in the modified alumina is γ-alumina.

4. The application according to claim 1, characterized in that Based on the weight of the catalyst, the content of molybdenum oxide is 4% - 24%, and the content of the support is 76% - 96%.

5. The application according to claim 1, wherein Based on the weight of the catalyst, the content of molybdenum oxide is 5.7% - 23%, and the content of the support is 77% - 94.3%.

6. The application according to claim 1, wherein The specific surface area of the catalyst is 200~350 m 2 / g, the pore volume is 0.2~0.55 cm 3 / g, and the total acid amount is 0.3~1.2 mmol / g.

7. The application according to claim 1, characterized in that, In step (a), the mass ratio of the raw alumina and distilled water is 0.5 - 5:10; in step (b), the alcohol is at least one of pure ethanol or propanol; in step (b), the mass ratio of the solid and the alcohol is 0.5 - 5:

10.

8. The application according to claim 1, characterized in that, The mass ratio of the raw alumina to the distilled water described in step (a) is 1 to 4:10; the alcohol in step (b) is at least one of pure ethanol and propanol; the mass ratio of the solid to the alcohol in step (b) is 1 to 4:

10.

9. The application according to claim 1, characterized in that, The mass ratio of the solid, aluminum nitrate, and distilled water described in step (c) is 1 to 10:1 to 20:100; and / or, the mass ratio of the solid, acetic acid, and distilled water described in step (d) is 1 to 10:20 to 60:1000.

10. The application according to claim 1, wherein The temperature of the acetic acid and distilled water mixture described in step (d) is maintained at 70 to 95 °C.

11. The application according to claim 1, characterized in that, The temperature of the acetic acid and distilled water mixture described in step (d) is maintained at 80 to 90 °C.

12. The application according to claim 1, wherein The molybdenum source described in step (f) includes at least one of ammonium heptamolybdate, ammonium dimolybdate, ammonium tetramolybdate, and ammonium octamolybdate; in the molybdenum-containing impregnation solution, the mass concentration of molybdenum in terms of MoO3 is 5% to 32%.

13. The application according to claim 1, wherein In the molybdenum-containing impregnation solution, the mass concentration of molybdenum in terms of MoO3 is 6% to 30%.

14. The application according to claim 1, wherein The high-temperature treatment time described in step (f) is 2 to 10 h.

15. The application according to claim 1, characterized in that, The high-temperature treatment time described in step (f) is 3 to 8 h.

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