A method for grading a diesel deep hydrodesulfurization catalyst

Abstract

The application provides a method for grading diesel deep hydrodesulfurization catalysts, which comprises the following steps: loading catalysts containing AlPO4-5 phosphorus aluminum molecular sieves and catalysts containing ETS-10 titanium silicon molecular sieves in the upper and lower parts of a fixed bed hydrogenation reactor respectively according to a loading mass ratio of 1:3-3:1, so that diesel is subjected to hydrodesulfurization reaction through catalysts containing AlPO4-5 phosphorus aluminum molecular sieves first and then through catalysts containing ETS-10 titanium silicon molecular sieves; the carrier of the catalysts containing AlPO4-5 phosphorus aluminum molecular sieves comprises AlPO4-5 phosphorus aluminum molecular sieves and aluminum oxide powder, the carrier of the catalysts containing ETS-10 titanium silicon molecular sieves comprises ETS-10 titanium silicon molecular sieves and aluminum oxide powder, and the active components of the two kinds of catalysts respectively comprise a combination of two or three of nickel oxide, molybdenum oxide and cobalt oxide. The sulfur content of the hydrogenated diesel obtained through the method can be as low as 10 μg / g or below.

Description

Technical Field

[0001] This invention relates to a gradation method for a diesel deep hydrodesulfurization catalyst, belonging to the field of hydrorefining technology. Background Technology

[0002] Hydrorefining technology is a widely used clean diesel production technology, and its core component is the diesel hydrorefining catalyst. As crude oil becomes increasingly degraded and heavier, the content of complex sulfides in diesel fractions continues to rise. Furthermore, with the continuous upgrading of diesel quality standards, the requirements for sulfur content in diesel are becoming increasingly stringent.

[0003] Numerous studies have shown that as the sulfur content of hydrotreated diesel decreases, the proportion of sterically hindered sulfides with complex structures gradually increases. When the sulfur content is less than 50 μg / g, the sulfides in hydrotreated diesel are mainly sterically hindered sulfides such as 4,6-dimethyldibenzothiophene. Because the methyl groups at the 4,6 positions prevent the catalyst active site from directly adsorbing the sulfur atoms, these sulfides cannot undergo direct desulfurization. Instead, they require hydrogenation saturation of one aromatic ring structure within the sulfide to form a cycloalkane ring. Only after this cycloalkane ring undergoes configurational inversion, exposing the sulfur atoms, can the sulfide react with the catalyst active site for hydrodesulfurization. In conclusion, the hydrogenation saturation process of the aromatic ring structure in these sulfides is crucial for their desulfurization.

[0004] In conventional industrial fixed-bed hydrotreating reactors, reactants (diesel and hydrogen) enter from the top and exit from the bottom. Since the hydrodesulfurization, denitrification, and aromatics and olefins hydrogenation saturation reactions involved in diesel hydrorefining are all exothermic, industrial fixed-bed hydrotreating reactors exhibit a temperature gradient of several tens of degrees Celsius from top to bottom, with the upper part being a low-temperature zone and the lower part a high-temperature zone. Because the aromatics hydrogenation saturation process releases a significant amount of heat, the chemical equilibrium of aromatics hydrogenation saturation is controlled by both reaction thermodynamics and reaction kinetics. Under constant reaction pressure, the aromatics hydrogenation saturation rate initially increases and then decreases with increasing reaction temperature. Therefore, in the same fixed-bed hydrotreating reactor, the lower part, located at a higher reaction temperature, is unfavorable for aromatics hydrogenation saturation, and consequently, for deep desulfurization reactions of structurally complex sulfides.

[0005] The presence of temperature gradients in fixed-bed hydrotreating reactors, particularly the high-temperature zone at the bottom, hinders the deep desulfurization of complex sulfides. To address this, a technique has been developed that utilizes catalysts with varying hydrotreating properties, employing graded packing to fully leverage the reactor's temperature distribution and achieve ultra-deep desulfurization.

[0006] For example, CN101591566A discloses a catalyst gradation method for deep hydrodesulfurization of diesel fuel. This method divides a fixed-bed hydrotreating reactor into four reaction zones from top to bottom, loading different functional catalysts into each zone: a hydrotreating protectant is loaded in the first hydrotreating zone; a hydrorefining catalyst I containing active cobalt-molybdenum is loaded in the second hydrotreating zone; a mixture of hydrorefining catalyst I and hydrorefining catalyst II is loaded in the third reaction zone; and a hydrorefining catalyst II containing active nickel-tungsten is loaded in the fourth reaction zone. By grading catalysts with different functions, the advantages of each catalyst at different desulfurization stages and the synergistic effect between catalysts are fully utilized, improving the overall catalyst activity and enabling the production of clean diesel fuel with a sulfur content of less than 50 μg / g under relatively mild conditions.

[0007] CN112852479A discloses a method for grading catalysts in diesel hydrorefining. This method divides a fixed-bed hydrorefining reactor into five reaction zones from top to bottom, and loads each zone with catalysts of different metal contents, particle sizes, and pore sizes. By grading different catalysts, the hydrorefining activity of each catalyst is fully utilized, thereby improving the hydrorefining activity of the graded catalyst and producing clean diesel with a sulfur content of less than 10 μg / g.

[0008] Therefore, in producing ultra-low sulfur diesel with a sulfur content of less than 10 μg / g by graded use of hydrorefining catalysts, existing technologies utilize the temperature gradient and reactant concentration gradient existing from top to bottom in a fixed-bed hydrorefining reactor to fully leverage the specific hydrorefining performance of each catalyst, thereby improving the hydrorefining activity of the combined catalyst and achieving deep removal of sulfides from diesel. However, the catalysts used in the catalyst grading process are usually supported by alumina or modified alumina, with metal salts of nickel, molybdenum, cobalt, and tungsten as active components. The hydrorefining activity of the catalyst is significantly affected by the properties of alumina. In addition, because existing grading methods usually use multiple catalysts (3-4 types), the actual application of catalyst grading technology in industrial plants suffers from complex loading and significant deviations between the actual operating reaction zones and the theoretically designed zones.

[0009] Therefore, providing a novel gradation method for diesel deep hydrodesulfurization catalysts has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0010] To address the aforementioned shortcomings and deficiencies, the present invention aims to provide a method for grading a catalyst for deep hydrodesulfurization of diesel fuel. This method is applicable to the hydrodesulfurization process of diesel fractions in the petroleum refining industry, and can produce ultra-low sulfur diesel fuel with a sulfur content of less than 10 μg / g.

[0011] To achieve the above objectives, the present invention provides a method for grading a diesel deep hydrodesulfurization catalyst, wherein the method for grading the diesel deep hydrodesulfurization catalyst includes:

[0012] The catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and the catalyst containing ETS-10 titanium silicon molecular sieve are loaded in a mass ratio of 1:3 to 3:1, and are respectively loaded into the upper and lower parts of the fixed bed hydrotreating reactor. The diesel fuel first passes through the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and then through the catalyst containing ETS-10 titanium silicon molecular sieve to carry out hydrodesulfurization reaction.

[0013] The catalysts containing AlPO4-5 phosphorus aluminum molecular sieves include AlPO4-5 phosphorus aluminum molecular sieves and alumina powder, etc., and the active components include two or three combinations of nickel oxide, molybdenum oxide and cobalt oxide.

[0014] The catalyst support containing ETS-10 titanium-silicon molecular sieve includes ETS-10 titanium-silicon molecular sieve and alumina powder, etc., and the active components include two or three of nickel oxide, molybdenum oxide and cobalt oxide.

[0015] As a specific embodiment of the method described above in this invention, in the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, the content of AlPO4-5 phosphorus aluminum molecular sieve is 5-30 wt% of the weight of alumina powder, and the content of active component is 22-32 wt% of the weight of catalyst.

[0016] In one specific embodiment of the method described above in this invention, the active components in the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve are NiO and MoO3. In some embodiments of this invention, the NiO content is preferably 4.8 wt% of the catalyst weight, and the MoO3 content is 24 wt% of the catalyst weight.

[0017] As a specific embodiment of the method described above in this invention, in the catalyst containing ETS-10 titanium silicate molecular sieve, the content of ETS-10 titanium silicate molecular sieve is 5-30 wt% of the weight of alumina powder, and the content of active component is 18-27 wt% of the weight of catalyst.

[0018] In one specific embodiment of the method described above in this invention, the active components in the catalyst containing ETS-10 titanium silicate molecular sieve are CoO and MoO3. In some embodiments of this invention, the CoO content is preferably 4.2 wt% of the catalyst weight, and the MoO3 content is 22 wt% of the catalyst weight.

[0019] In one specific embodiment of the method described above in this invention, the alumina powder is commercially available boehmite with a specific surface area of ​​340-400 m². 2 / g, with a pore volume of 0.90-1.10mL / g.

[0020] In one specific embodiment of the method described above in this invention, the specific surface area of ​​the AlPO4-5 phosphorus aluminum molecular sieve is 280-300 m². 2 / g, pore volume is 0.22-0.26mL / g, and grain size is less than 2μm.

[0021] In one specific embodiment of the method described above in this invention, the specific surface area of ​​the ETS-10 titanium-silicon molecular sieve is 330-360 m². 2 / g, pore volume is 0.18-0.22mL / g, and grain size is less than 2μm.

[0022] In a specific embodiment of the method described above in this invention, the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and the catalyst containing ETS-10 titanium silicon molecular sieve are respectively fine strips with a diameter of 0.8-2.0 mm or coarse strips with a diameter >2.5 mm, preferably fine strips with a diameter of 1.2-1.6 mm.

[0023] As a specific embodiment of the method described above in this invention, the shape of the carrier includes sheet-like, toothed ball-shaped, Raschig ring, cylindrical strip, or irregular strip, etc., wherein the irregular strip includes clover or four-leaf clover, etc.; preferably, the shape of the carrier is cylindrical strip, clover, or four-leaf clover.

[0024] As a specific embodiment of the method described above in this invention, the method for preparing the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve includes:

[0025] Step (1): Weigh a certain amount of alumina powder and AlPO4-5 phosphorus aluminum molecular sieve, mix the two solid powders with binder and extrusion aid in a certain proportion, and then extrude, dry and calcine to obtain catalyst support I;

[0026] Step (2): Dissolve the active component metal salt in deionized water in a certain proportion to prepare a clear and transparent impregnation solution containing the active component metal. Use the equal volume impregnation method to impregnate the catalyst support I in the impregnation solution containing the active component metal. After curing, drying and calcining, a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve is obtained.

[0027] As a specific embodiment of the method described above in this invention, in step (2), the drying temperature is 100-140℃, the drying time is 2-5h, the calcination temperature is 400-500℃, and the calcination time is 3-6h.

[0028] This invention does not impose specific requirements on the binder and extrusion aid used in step (1), as well as the operating steps and process conditions such as extrusion molding, drying, and calcination. These can be reasonably selected and adjusted according to the actual needs of the on-site operation. In some embodiments of this invention, step (1) can be performed according to the following specific steps:

[0029] First, alumina powder and AlPO4-5 phosphorus aluminum molecular sieve are mixed. After the alumina powder and AlPO4-5 phosphorus aluminum molecular sieve are mixed evenly, the resulting mixed powder is mixed evenly with binder and extrusion aid in a certain proportion. Then, it is extruded, dried and calcined to obtain catalyst support I.

[0030] As a specific embodiment of the method described above in this invention, the method for preparing the catalyst containing ETS-10 titanium-silicon molecular sieve includes:

[0031] Step 1): Weigh a certain amount of alumina powder and ETS-10 titanium silicon molecular sieve, mix the two solid powders with binder and extrusion aid in a certain proportion, and then extrude, dry and calcine to obtain catalyst support II.

[0032] Step 2): Dissolve the active component metal salt in deionized water in a certain proportion to prepare a clear and transparent impregnation solution containing the active component metal. Use the equal volume impregnation method to impregnate catalyst support II in the impregnation solution containing the active component metal. After curing, drying and calcination, a catalyst containing ETS-10 titanium silicon molecular sieve is obtained.

[0033] In a specific embodiment of the method described above in this invention, in step 2), the drying temperature is 100-140℃, the drying time is 2-5h, the calcination temperature is 400-500℃, and the calcination time is 3-6h.

[0034] This invention does not impose specific requirements on the binder and extrusion aid used in step 1), as well as the operating steps and process conditions such as extrusion molding, drying, and calcination. These can be reasonably selected and adjusted according to the actual needs of the on-site operation. In some embodiments of this invention, step 1) can be operated according to the following specific steps:

[0035] First, alumina powder and ETS-10 titanium-silicon molecular sieve are mixed. After the alumina powder and ETS-10 titanium-silicon molecular sieve are evenly mixed, the resulting mixed powder is mixed evenly with binder and extrusion aid in a certain proportion. Then, it is extruded, dried and calcined to obtain catalyst carrier II.

[0036] As a specific embodiment of the method described above in this invention, the diesel oil includes one or a mixture of several of straight-run diesel oil, catalytic diesel oil, and coking diesel oil.

[0037] In one specific embodiment of the method described above, the conditions for the hydrodesulfurization reaction include: a reaction temperature of 340-400℃, a reaction pressure of 4-7 MPa, and a space velocity of 1.0-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-500:1.

[0038] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0039] (1) The gradation method of the diesel deep hydrodesulfurization catalyst provided by the present invention uses a hydrodesulfurization catalyst containing molecular sieves with specific functions, namely a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and a catalyst containing ETS-10 titanium silicon molecular sieve, which are respectively suitable for aromatic hydrogenation saturation and hydrodesulfurization reaction processes.

[0040] (2) The gradation method of diesel deep hydrodesulfurization catalyst provided by the present invention can reduce the types of catalysts, reduce the complexity of catalyst loading in industrial plants, and improve the matching of catalysts to actual reaction zones in industrial plants.

[0041] (3) The gradation method of the diesel deep hydrodesulfurization catalyst provided by the present invention optimizes the process conditions of the deep hydrodesulfurization reaction process of different raw materials by evaluating the hydrogenation of different raw materials.

[0042] In summary, the gradation method for diesel deep hydrodesulfurization catalysts provided by this invention can be used in the diesel deep hydrodesulfurization process. It can fully utilize the temperature gradient of tens of degrees Celsius existing from top to bottom in the reactor of an industrial diesel hydrotreating unit, and by using different types of catalysts, fully leverage the hydrogenation activity of different catalysts to achieve deep removal of structurally complex sulfides (4,6-dimethyldibenzothiophene) from diesel fractions. The sulfur content of hydrotreated diesel obtained through this gradation method can be as low as below 10 μg / g. Detailed Implementation

[0043] It should be noted that the term "comprising" and any variations thereof in the specification and claims of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0044] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0045] In this invention, unless otherwise specified, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this invention, and "0-5" is simply a shortened representation of these numerical combinations.

[0046] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0047] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0048] In this invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the appendix and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially. For example, the alumina powder used in the embodiments was produced by Shandong Yuneng Catalyst Technology Co., Ltd., and the AlPO4-5 phosphorus aluminum molecular sieve and ETS-10 titanium silicon molecular sieve used were prepared in the laboratory using existing conventional methods.

[0050] Carrier Examples

[0051] Example 1

[0052] This embodiment provides a support for a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0053] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and 15 g of a specific surface area of ​​294 m² / g were added to the alumina powder. 2 AlPO4-5 phosphorus aluminum molecular sieve with a pore volume of 0.24 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and then a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 255 g of deionized water was added dropwise and kneaded. The mixture was extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier I-1#.

[0054] Example 2

[0055] This embodiment provides a support for a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0056] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​294 m² / g was added to the alumina powder. 2AlPO4-5 phosphorus aluminum molecular sieve with a pore volume of 0.24 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 255 g of deionized water was added dropwise and kneaded. The mixture was extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier I-2#.

[0057] Example 3

[0058] This embodiment provides a support for a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0059] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​294 m² / g was added to the alumina powder. 2 AlPO4-5 phosphorus aluminum molecular sieve with a pore volume of 0.24 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 270 g of deionized water was added dropwise and kneaded. The mixture was extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare a carrier, designated as carrier I-3#.

[0060] Example 4

[0061] This embodiment provides a support for a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0062] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​294 m² / g was added to the alumina powder. 2 AlPO4-5 phosphorus aluminum molecular sieve with a pore volume of 0.24 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 285 g of deionized water was added dropwise and kneaded. The mixture was then extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier I-4#.

[0063] Example 5

[0064] This embodiment provides a support for a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0065] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​340 m² / g was added to the alumina powder. 2 ETS-10 titanium-silicon molecular sieve with a pore volume of 0.20 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 255 g of deionized water was added dropwise and kneaded. The mixture was extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier II-1#.

[0066] Example 6

[0067] This embodiment provides a support for a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0068] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​340 m² / g was added to the alumina powder. 2 ETS-10 titanium-silicon molecular sieve with a pore volume of 0.20 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 255 g of deionized water was added dropwise and kneaded. The mixture was then extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier II-2#.

[0069] Example 7

[0070] This embodiment provides a support for a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0071] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​340 m² / g was added to the alumina powder. 2 ETS-10 titanium-silicon molecular sieve with a pore volume of 0.20 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 270 g of deionized water was added dropwise and kneaded. The mixture was then extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier II-3#.

[0072] Example 8

[0073] This embodiment provides a support for a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0074] Take 300g, the specific surface area is 360m² 2 Alumina powder with a pore volume of 0.95 mL / g and a specific surface area of ​​340 m² / g was added to the alumina powder. 2 ETS-10 titanium-silicon molecular sieve with a pore volume of 0.20 mL / g and a crystal size of 0.5-2 μm, 9 g of guar gum powder, were mixed evenly, and a mixed solution consisting of 9 g of nitric acid (68 wt%), 15 g of citric acid and 294 g of deionized water was added dropwise and kneaded. The mixture was then extruded into 1.5 mm clover-shaped strips, dried at 120 °C for 2 h, and then calcined at 550 °C for 4 h to prepare the carrier, designated as carrier II-4#.

[0075] Catalyst Examples

[0076] Example 9

[0077] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0078] Take 50g of support I-1# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3h, then calcine it at 450℃ for 4h to prepare the catalyst, designated as catalyst I-1#. The catalyst contains 4.8wt% NiO and 24wt% MoO3 by weight.

[0079] Example 10

[0080] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0081] Take 50g of support I-2# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst I-2#. The catalyst contains 4.8wt% NiO and 24wt% MoO3 by weight.

[0082] Example 11

[0083] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0084] Take 50g of support I-3# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst I-3#. The catalyst contains 4.8wt% NiO and 24wt% MoO3 by weight.

[0085] Example 12

[0086] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0087] Take 50g of support I-4# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3h, then calcine it at 450℃ for 4h to prepare the catalyst, designated as catalyst I-4#. The catalyst contains 4.8wt% NiO and 24wt% MoO3 by weight.

[0088] Example 13

[0089] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0090] Take 50g of support II-1# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-1#. The catalyst contains 4.2wt% CoO and 22wt% MoO3 by weight.

[0091] Example 14

[0092] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0093] Take 50g of support II-2# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-2#. The catalyst contains 4.2wt% CoO and 22wt% MoO3 by weight.

[0094] Example 15

[0095] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0096] Take 50g of support II-3# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-3#. The catalyst contains 4.2wt% CoO and 22wt% MoO3 by weight.

[0097] Example 16

[0098] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0099] Take 50g of support II-4# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-4#. The catalyst contains 4.2wt% CoO and 22wt% MoO3 by weight.

[0100] Comparative Example 1

[0101] This comparative example provides a hydrodesulfurization catalyst, which is prepared by a method including the following specific steps:

[0102] Take 100g with a specific surface area of ​​360m² 2 / g, alumina powder with a pore volume of 0.95mL / g, 3g guar gum powder, mixed evenly, and a mixed solution consisting of 3g nitric acid (68wt%), 5g citric acid and 80g deionized water was added dropwise and kneaded. The mixture was extruded into clover-shaped strips of 1.5mm, dried at 120℃ for 2h, and then calcined at 550℃ for 4h to prepare a control carrier.

[0103] 50g of a control support was weighed and impregnated with Ni-Mo impregnation solution using an equal-volume impregnation method. The Ni-Mo impregnation support was dried at 120℃ for 3 hours and then calcined at 450℃ for 4 hours to prepare the catalyst, designated as control catalyst #1. The catalyst contained 4.8 wt% NiO and 24 wt% MoO3 by weight.

[0104] Comparative Example 2

[0105] This comparative example provides a hydrodesulfurization catalyst, which is prepared by a method including the following specific steps:

[0106] Take 100g with a specific surface area of ​​360m² 2 / g, alumina powder with a pore volume of 0.95mL / g, 3g guar gum powder, mixed evenly, and a mixed solution consisting of 3g nitric acid (68wt%), 5g citric acid and 80g deionized water was added dropwise and kneaded. The mixture was extruded into clover-shaped strips of 1.5mm, dried at 120℃ for 2h, and then calcined at 550℃ for 4h to prepare a control carrier.

[0107] 50g of a control support was weighed and impregnated with a Co-Mo impregnation solution using an equal-volume impregnation method. The support impregnated with the Co-Mo solution was dried at 120℃ for 3 hours and then calcined at 450℃ for 4 hours to prepare a catalyst, designated as control catalyst #2. The catalyst contained 4.2 wt% CoO and 22 wt% MoO3 by weight.

[0108] Example 17

[0109] This embodiment uses diesel feedstock to evaluate the hydrodesulfurization performance of the catalysts provided in Examples 9-16 and Comparative Examples 1-2. The diesel feedstock is a blend of straight-run diesel and catalytic diesel from a refinery, with a sulfur content of 3460 μg / g and an aromatic content of 54 wt%. The hydrodesulfurization evaluation process conditions are: reaction temperature 350℃, reaction pressure 7.0 MPa, and space velocity 1.5 h⁻¹. -1 The hydrogen-to-oil ratio was 500:1. The evaluation data obtained in this embodiment are shown in Table 1.

[0110] Table 1. Hydrodesulfurization and aromatic saturation effects of catalysts prepared with different molecular sieve contents.

[0111]

[0112]

[0113] As shown in Table 1, in catalysts containing AlPO4-5 phosphorus aluminum molecular sieve, when the amount of AlPO4-5 phosphorus aluminum molecular sieve exceeds 20 wt% of the alumina powder weight, the increase in desulfurization activity and aromatic saturation activity decreases significantly with increasing AlPO4-5 phosphorus aluminum molecular sieve content. Therefore, support I-3# is the preferred support for catalysts containing AlPO4-5 phosphorus aluminum molecular sieve. In catalysts containing ETS-10 titanium silicon molecular sieve, when the amount of ETS-10 titanium silicon molecular sieve exceeds 10 wt% of the alumina powder weight, the increase in desulfurization activity and aromatic saturation activity decreases significantly with increasing ETS-10 titanium silicon molecular sieve content. Therefore, support II-2# is the preferred support for catalysts containing ETS-10 titanium silicon molecular sieve.

[0114] Example 18

[0115] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0116] Take 50g of support I-3# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst I-5#. The catalyst contains 5.0 wt% NiO and 26.5 wt% MoO3 by weight.

[0117] Example 19

[0118] This embodiment provides a catalyst containing AlPO4-5 phosphorus aluminum molecular sieve, which is prepared by a method including the following specific steps:

[0119] Take 50g of support I-3# and impregnate it with Ni-Mo impregnation solution using the equal-volume impregnation method. Dry the Ni-Mo impregnation solution-impregnated support at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst I-6#. The catalyst contains 4.0 wt% NiO and 18.5 wt% MoO3 by weight.

[0120] Example 20

[0121] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0122] Take 50g of support II-2# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-5#. The catalyst contains 4.0 wt% CoO and 14 wt% MoO3.

[0123] Example 21

[0124] This embodiment provides a catalyst containing ETS-10 titanium-silicon molecular sieve, which is prepared by a method including the following specific steps:

[0125] Take 50g of support II-2# and impregnate it with Co-Mo impregnation solution using the equal-volume impregnation method. Dry the support impregnated with Co-Mo solution at 120℃ for 3 hours, then calcine it at 450℃ for 4 hours to prepare the catalyst, designated as catalyst II-6#. The catalyst contains 4.0 wt% CoO and 18 wt% MoO3 by weight.

[0126] Example 22

[0127] This embodiment evaluates the hydrodesulfurization performance of the catalysts provided in Examples 18-21, as well as those provided in Examples 11 and 14, using diesel feedstock. The diesel feedstock is a blend of straight-run diesel and catalytic diesel from a refinery, with a sulfur content of 3460 μg / g and an aromatic content of 54 wt%. The hydrodesulfurization evaluation process conditions are: reaction temperature 350℃, reaction pressure 7.0 MPa, and space velocity 1.5 h⁻¹. -1 The hydrogen-to-oil ratio was 500:1. The evaluation data obtained in this embodiment are shown in Table 2.

[0128] Table 2. Hydrodesulfurization and aromatic saturation effects of catalysts prepared with different active metal contents.

[0129]

[0130] As can be seen from the catalyst hydrogenation evaluation results shown in Table 2, the catalysts provided in the embodiments of the present invention have relatively high hydrodesulfurization activity when Ni-Mo is used as the active metal and the metal oxide content is 28.8 wt%; and when Co-Mo is used as the active metal and the metal oxide content is 26.2 wt%, the catalysts have relatively high hydrodesulfurization activity.

[0131] Example 23

[0132] This embodiment provides a method for grading a diesel deep hydrodesulfurization catalyst, wherein the method includes the following specific steps:

[0133] Catalysts I-3 and II-2 were loaded into a fixed-bed hydrotreating reactor in equal mass. The reactor was divided into two reaction zones from top to bottom: reaction zone 1 and reaction zone 2. The effect of catalyst loading in different reaction zones on the gradation effect was investigated. The feedstock used in this example was a mixture of straight-run diesel and catalytic diesel from a refinery, with a sulfur content of 3460 μg / g. The evaluation process conditions for catalyst hydrodesulfurization were: reaction temperature of 350℃ in reaction zone 1, reaction temperature of 375℃ in reaction zone 2, reaction pressure of 7.0 MPa, and space velocity of 1.5 h⁻¹. -1 The hydrogen-to-oil ratio was 500:1. Evaluation data are shown in Table 3.

[0134] Table 3. Effect of catalyst loading sequence in the reactor on the hydrodesulfurization efficiency of the catalyst.

[0135]

[0136] As can be seen from Table 3, when catalysts I-3# and II-2# are mixed in equal mass, the combined catalyst exhibits higher desulfurization activity when catalyst I-3# is in reaction zone 1 (upper part of the fixed-bed hydrogenation reactor) and catalyst II-2# is in reaction zone 2 (lower part of the fixed-bed hydrogenation reactor).

[0137] Example 24

[0138] This embodiment provides a method for grading a diesel deep hydrodesulfurization catalyst, wherein the method includes the following specific steps:

[0139] Using catalysts I-3# and II-2#, with catalyst I-3# loaded in reaction zone 1 and catalyst II-2# loaded in reaction zone 2, the effect of varying relative loading amounts of the two catalysts on the gradation effect was investigated. The feedstock used in this example was a blend of straight-run diesel and catalytic diesel from a refinery, with a sulfur content of 3460 μg / g. The evaluation process conditions for catalyst hydrodesulfurization were: reaction temperature 350℃ in reaction zone 1, reaction temperature 375℃ in reaction zone 2, reaction pressure 7.0 MPa, and space velocity 1.5 h⁻¹. -1 The hydrogen-to-oil ratio was 500:1. Evaluation data is shown in Table 4.

[0140] Table 4. Effect of relative catalyst content on the hydrodesulfurization efficiency of combined catalysts

[0141]

[0142]

[0143] As can be seen from Table 4, compared with the two comparative gradation methods 4 and 12, the sulfur content of the hydrotreated diesel obtained by gradation methods 5-11 is significantly reduced. Comparing gradation methods 5-11, it can be seen that the sulfur content of the hydrotreated diesel obtained by gradation method 11 is 8.9 μg / g, which is the most outstanding desulfurization effect among the gradation methods investigated.

[0144] Example 25

[0145] This embodiment provides a method for grading a diesel deep hydrodesulfurization catalyst, wherein the method includes the following specific steps:

[0146] Using the catalyst gradation and loading scheme corresponding to gradation method 11 shown in Table 4, and taking a mixture of catalytic cracking diesel (catalytic diesel), straight-run diesel, coking diesel or the above diesel fractions from a certain refinery as raw materials, the effect of the graded catalyst on the hydrodesulfurization of various diesel fractions under different process conditions was investigated. The experimental results are shown in Table 5.

[0147] Table 5. Effects of catalyst gradation method 11 on hydrodesulfurization of different feedstocks under different conditions.

[0148]

[0149]

[0150] As can be seen from Table 5 above, hydrodesulfurization of various diesel fractions using gradation method 11 and different process conditions can significantly reduce the sulfur content of hydrotreated diesel. However, under condition 1, when the temperature of reaction zone 1 is 320℃, the sulfur content of the obtained hydrotreated diesel is relatively high, at 56 μg / g. Under other process conditions, the sulfur content of the obtained hydrotreated diesel is below 31 μg / g. Under some preferred process conditions, such as conditions 3-8, the sulfur content of hydrotreated diesel can even be reduced to below 10 μg / g.

[0151] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A method for grading a diesel deep hydrodesulfurization catalyst, characterized in that, The method includes: The catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and the catalyst containing ETS-10 titanium silicon molecular sieve are loaded in a mass ratio of 1:3 to 3:1, and are respectively loaded into the upper and lower parts of the fixed bed hydrotreating reactor. The diesel fuel first passes through the catalyst containing AlPO4-5 phosphorus aluminum molecular sieve and then through the catalyst containing ETS-10 titanium silicon molecular sieve to carry out hydrodesulfurization reaction. The catalyst containing AlPO4-5 phosphorus aluminum molecular sieve is supported by AlPO4-5 phosphorus aluminum molecular sieve and alumina powder, and the active components include two or three of nickel oxide, molybdenum oxide and cobalt oxide. The catalyst support containing ETS-10 titanium-silicon molecular sieve includes ETS-10 titanium-silicon molecular sieve and alumina powder, and the active components include two or three of nickel oxide, molybdenum oxide and cobalt oxide.

2. The method according to claim 1, characterized in that, In catalysts containing AlPO4-5 phosphorus aluminum molecular sieve, the content of AlPO4-5 phosphorus aluminum molecular sieve is 5-30 wt% of the weight of alumina powder, and the content of active component is 22-32 wt% of the weight of catalyst.

3. The method according to claim 1, characterized in that, In catalysts containing ETS-10 titanium-silicon molecular sieve, the content of ETS-10 titanium-silicon molecular sieve is 5-30 wt% of the weight of alumina powder, and the content of active component is 18-27 wt% of the weight of catalyst.

4. The method according to any one of claims 1-3, characterized in that, The specific surface area of ​​the alumina powder is 340-400 m². 2 / g, with a pore volume of 0.90-1.10mL / g.

5. The method according to any one of claims 1-3, characterized in that, The specific surface area of ​​the AlPO4-5 phosphorus aluminum molecular sieve is 280-300 m². 2 / g, pore volume is 0.22-0.26mL / g, and grain size is less than 2μm.

6. The method according to any one of claims 1-3, characterized in that, The specific surface area of ​​the ETS-10 titanium-silicon molecular sieve is 330-360 m². 2 / g, pore volume is 0.18-0.22mL / g, and grain size is less than 2μm.

7. The method according to any one of claims 1-3, characterized in that, The catalysts containing AlPO4-5 phosphorus aluminum molecular sieve and the catalysts containing ETS-10 titanium silicon molecular sieve are respectively fine strips with a diameter of 0.8-2.0 mm or coarse strips with a diameter of >2.5 mm.

8. The method according to any one of claims 1-3, characterized in that, The carrier can be in the shape of a sheet, a toothed ball, a Raschig ring, a cylindrical strip, or an irregular strip, wherein the irregular strip includes a clover or a four-leaf clover.

9. The method according to any one of claims 1-3, characterized in that, The diesel fuel includes one or a mixture of several of the following: straight-run diesel, catalytic diesel, and coking diesel.

10. The method according to any one of claims 1-3, characterized in that, The conditions for the hydrodesulfurization reaction include: a reaction temperature of 340-400℃, a reaction pressure of 4-7 MPa, and a space velocity of 1.0-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200-500:1.

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