A grading method and application of heavy oil hydroprocessing catalyst

Abstract

The present invention discloses a grading method and application of a heavy oil hydroprocessing catalyst. The method comprises at least two reactors connected in series in sequence, wherein the first reactor along the logistics direction is recorded as the first reactor; at least one hydrogenation protection catalyst, at least one first hydrodemetallization catalyst, and at least one second hydrodemetallization catalyst are sequentially loaded in the first reactor along the logistics direction; the particle size, pore size, porosity, and active metal content of any second hydrodemetallization catalyst are respectively greater than the particle size, pore size, porosity, and active metal content of the upstream catalyst adjacent thereto. The grading method is applied to the heavy oil hydrogenation reaction, which can reduce the deposition of metal impurities and carbon deposits on the catalyst, slow down the catalyst deactivation rate, improve the demetallization, desulfurization, and residual carbon removal stability of the entire system, and extend the operation cycle of the catalyst.

Description

Technical Field

[0001] The invention belongs to the field of heavy oil hydroprocessing, and specifically relates to a grading method and application of a heavy oil hydroprocessing catalyst. The grading method is particularly suitable for the hydroprocessing process of residual oil with high metal impurities and Conradson carbon residue content. Background Art

[0002] Heavy oil hydroprocessing can increase the production of light oil products while meeting stricter environmental regulations. It is one of the effective technical solutions to help refiners meet the current market demand. At present, the most widely used and mature process for residual oil hydroprocessing in industry is the fixed bed hydrogenation process. Usually, the industrial unit consists of at least two reactors (demetallization reactor and desulfurization reactor).

[0003] Since heavy oil, especially residual oil, has a complex composition and contains a large amount of impurities, especially metals such as Ni, V, Fe, Ca, and Na, which have a poisoning effect on desulfurization catalysts and carbon removal catalysts, heavy oil hydroprocessing generally adopts "catalyst combination loading technology" to gradually reduce the metal content in the feed to protect the downstream highly active hydrodesulfurization, denitrification / carbon removal catalysts, that is, use two or more catalysts with different functions. The functional catalysts include hydrogenation protective agents, hydrodemetallization catalysts, hydrodesulfurization catalysts, hydrodenitrogenation / carbon removal catalysts, etc. The conventional catalyst grading loading principle is: along the direction of the raw material flow, the content of the catalyst active component gradually increases, the pore size gradually decreases, the particle size gradually decreases, and the porosity gradually decreases.

[0004] US4447314 proposes a dual catalyst system for residual oil hydroprocessing. The first catalyst is a macroporous catalyst and the second catalyst is a small pore catalyst. The raw material first passes through the first catalyst and then sequentially passes through the second catalyst to achieve demetallization and desulfurization of the residual oil.

[0005] US4306964 discloses a method for demetallizing residual oil. The method is to contact the oil successively with three or more stages of catalysts having successively decreasing average pore diameters and successively increasing specific surface areas, wherein the first stage catalyst has at least 60% of its pore diameters being The pore volume of pores with a diameter of 10-20 nm is up to 5% of the pores with a diameter larger than The pore volume of pores with a diameter of 50 nm and a specific surface area of ​​up to 120 m 2 / g, the second stage catalyst has at least 40% pore size The pore volume of pores with a diameter of 5-10 nm and a specific surface area of ​​120-180 m 2 / g, the last stage catalyst has at least 60% pore size The pore volume of pores (3-8nm) and the specific surface area are at least 200m 2 / g.

[0006] CN1197105A discloses a method for hydrotreating hydrocarbon raw materials containing metal pollutants. The method is to contact the raw materials with one or more catalyst beds of the first catalyst, the second catalyst, and the third catalyst in the presence of hydrogen. The properties and functions of the catalysts in each bed are different. In fact, along the direction of logistics, the catalyst activity gradually increases and the pore size gradually decreases. It is a conventional hydrotreating process of first demetallization, then desulfurization, and finally denitrification. The method can reduce the metal content in the feed step by step to protect the downstream highly active hydrodesulfurization and denitrification catalysts. Its disadvantages are that the temperature rise in the lower part of the reactor is high, the hydrogen purity is low, and the deposition of metal impurities and carbon deposits in the lower part of the reactor is serious, which will restrict the long-term operation of the heavy oil hydrogenation unit. Especially when processing inferior residual oil with high metal and Conradson carbon content, it is very easy to cause orifice blockage, resulting in rapid decay of catalyst activity and poor stability.

[0007] CN1393518A discloses a grading method for residual oil hydroprocessing catalyst. The method is to divide the desulfurization or denitrification reaction zone into two or more catalyst beds, and add a mixed transition bed between the two beds. The catalyst grading method of the desulfurization reaction zone or the denitrification reaction zone is different from the commonly used grading method. The principle of gradually reducing the activity of the catalyst along the logistics direction is adopted to change the grading of the desulfurization catalyst and denitrification catalyst beds, and add a transition catalyst bed between the beds, so that the temperature rise of each catalyst bed is more stable. Compared with the traditional method, the temperature rise of each catalyst bed in this method is easy to control, no hot spots will appear in the reaction zone, and the hydrogen consumption is greatly reduced. However, it fails to solve the problem that the excessive deposition of metal impurities and carbon deposits in the lower part of the reactor leads to rapid decay of catalyst activity. Summary of the invention

[0008] In view of the problem that excessive deposition of metal impurities and carbon deposits in the lower part of the reactor leads to rapid attenuation of catalyst activity, the present invention provides a grading method and application of a heavy oil hydroprocessing catalyst. The grading method of the present invention is applied to heavy oil hydrogenation reaction, which can reduce the deposition of metal impurities and carbon deposits on the catalyst, slow down the deactivation rate of the catalyst, improve the demetallization, desulfurization and residual carbon removal stability of the entire system, and extend the operation cycle of the catalyst.

[0009] The first aspect of the present invention provides a grading method for a heavy oil processing hydrogenation catalyst, comprising at least two reactors connected in series in sequence, the first reactor along the logistics direction being denoted as the first reactor; at least one hydrogenation protection catalyst, at least one first hydrogenation demetallization catalyst, and at least one second hydrogenation demetallization catalyst are sequentially loaded in the first reactor along the logistics direction; the particle size, pore size, porosity, and active metal content of any second hydrogenation demetallization catalyst are respectively greater than the particle size, pore size, porosity, and active metal content of the upstream catalyst adjacent thereto.

[0010] According to the present invention, the loading method of the second hydrodemetallization catalyst refers to the loading method of each second hydrodemetallization catalyst loaded in the second hydrodemetallization reaction zone relative to the first hydrodemetallization catalyst loaded in the first hydrodemetallization reaction zone adjacent to the second hydrodemetallization reaction zone, along the direction of the reactant flow, the particle size increases from small to large, the pore size increases from small to large, the porosity increases from small to large, and the active metal content increases from low to high.

[0011] According to the present invention, the second hydrodemetallization catalyst is loaded in the direction of the material flow, with the particle size of the catalyst increasing from small to large, the pore size increasing from small to large, the porosity increasing from small to large, and the active metal content increasing from low to high.

[0012] According to the present invention, the hydrogenation protection catalyst is a combination of multiple hydrogenation protection catalysts, preferably 2 to 4 types.

[0013] According to the present invention, preferably, the number of the first hydrodemetallization catalysts is 2 to 4.

[0014] According to the present invention, preferably, the second hydrodemetallization catalysts are 2 to 4. Preferably, the loading volume of each catalyst accounts for at least 5%, preferably 10% to 70%, and more preferably 20% to 60% of the total volume of the catalyst loaded in the second hydrodemetallization reaction zone.

[0015] According to the present invention, the hydrogenation protection catalyst and the first hydrodemetallization catalyst are loaded in a conventional manner and can be loaded according to conventional grading principles, that is, along the logistics direction, the particle size is from large to small, the pore size is from large to small, the porosity is from large to small, and the active metal content is from low to high.

[0016] According to the present invention, based on the total volume of the catalyst in the first reactor, the hydrogenation protection catalyst accounts for 10% to 60% of the volume, preferably 20% to 50% of the volume; the first hydrodemetallization catalyst accounts for 10% to 50% of the volume, preferably 30% to 50% of the volume; the second hydrodemetallization catalyst accounts for 10% to 50% of the volume, preferably 20% to 30% of the volume.

[0017] According to the present invention, the composition of the hydrogenation protection catalyst includes: a porous oxide as a carrier, and a VIB group metal and / or a VIII group metal as an active metal component. Based on the mass of the hydrogenation protection catalyst, the content of the active metal in the oxide is 0wt% to 10wt%, and the content of the carrier is 90wt% to 100wt%. The porous oxide is preferably alumina. The VIB group metal is at least one selected from Mo and W; the VIII group metal is at least one selected from Co and Ni. Preferably, one or more of P, B, Si, F, Ti and Zr can be added as an additive.

[0018] According to the present invention, the composition of the first hydrodemetallization catalyst includes: a porous oxide as a carrier, and a VIB group metal and / or a VIII group metal as an active metal component. Based on the mass of the first hydrodemetallization catalyst, the content of the active metal in terms of oxide is 5wt% to 12wt%, and the content of the carrier is 88wt% to 95wt%. The porous oxide is preferably alumina. The VIB group metal is at least one selected from Mo and W; the VIII group metal is at least one selected from Co and Ni. Preferably, one or more of P, B, Si, F, Ti and Zr can be added as an additive.

[0019] According to the present invention, the composition of the second hydrodemetallization catalyst includes: a porous oxide as a carrier, and a VIB group metal and / or a VIII group metal as an active metal component. Based on the mass of the second hydrodemetallization catalyst, the content of the active metal in terms of oxide is 8wt% to 16wt%, and the content of the carrier is 84wt% to 92wt%. The porous oxide is preferably alumina. The VIB group metal is at least one selected from Mo and W; the VIII group metal is at least one selected from Co and Ni. Preferably, one or more of P, B, Si, F, Ti and Zr can be added as an additive.

[0020] According to the present invention, the active metal content of any second hydrodemetallization catalyst is higher than the active metal content of the adjacent upstream catalyst, calculated as oxide; preferably, the active metal weight content of any second hydrodemetallization catalyst is 0.7 to 6.0 percentage points higher than the active metal weight content of the adjacent upstream catalyst, calculated as oxide.

[0021] According to the present invention, preferably, the active metals in the second hydrodemetallization catalyst include Mo and Ni; the active metals in the first hydrodemetallization catalyst adjacent to the second hydrodemetallization catalyst include Mo and Ni; the composition of the first hydrodemetallization catalyst includes, based on the mass of the first hydrodemetallization catalyst, an aluminum oxide content of 88 wt% to 95 wt%, Mo content of 3.8 wt% to 10 wt% in terms of oxide, and Ni content of 1.2 wt% to 2 wt%; the composition of the second hydrodemetallization catalyst includes, based on the mass of the second hydrodemetallization catalyst, an aluminum oxide content of 84 wt% to 92 wt%, Mo content of 6.5 wt% to 13.5 wt% in terms of oxide, and Ni content of 1.5 wt% to 3.5 wt%. Preferably, in terms of oxide, any second hydrodemetallization catalyst has a Mo weight content higher by 0.3 to 4 percentage points, preferably higher by 0.3 to 3 percentage points, and a Ni weight content higher by 0.4 to 2.0 percentage points, preferably higher by 0.4 to 1.5 percentage points than that in the adjacent upstream catalyst.

[0022] According to the present invention, the particle size of the hydrogenation protection catalyst is 1.5 to 10 mm, the pore size is 10 to 100 nm, and the porosity is 45.0% to 60.0%.

[0023] According to the present invention, the particle size of the first hydrodemetallization catalyst is 1.0 to 2.5 mm, the pore size is 10 to 30 nm, and the porosity is 42.0% to 46.0%.

[0024] According to the present invention, the particle size of the second hydrodemetallization catalyst is 1.5-2.7 mm, the pore size is 15-33 nm, and the porosity is 44.0%-47.0%.

[0025] According to the present invention, the particle size of any second hydrodemetallization catalyst is larger than the particle size of its adjacent upstream catalyst. Preferably, the particle sizes of the two adjacent catalysts differ by at least 0.3 mm, preferably 0.3 to 1.0 mm.

[0026] According to the present invention, the pore size of any second hydrodemetallization catalyst is larger than the pore size of its adjacent upstream catalyst. Preferably, the pore sizes of two adjacent catalysts differ by at least 1.5 nm, preferably 1.5 nm to 5 nm.

[0027] According to the present invention, the porosity of any second hydrodemetallization catalyst is greater than the porosity of its adjacent upstream catalyst. Preferably, the porosity of two adjacent catalysts differs by at least 0.3 percentage points, preferably 0.5 to 3 percentage points.

[0028] According to the present invention, according to conventional methods, after the second hydrodemetallization catalyst, at least one hydrodesulfurization catalyst may be included in the logistics direction. At least one hydrodecarbonation catalyst may also be included. The hydrodesulfurization catalyst and the hydrodecarbonation catalyst are loaded in other reactors except the first reactor, and one reactor or multiple reactors may be used.

[0029] According to the present invention, preferably, a hydrodemetallization catalyst may be loaded upstream of the hydrodesulfurization catalyst. The hydrodemetallization catalyst is not in the first reactor. The purpose of loading the hydrodemetallization catalyst upstream of the hydrodesulfurization catalyst is to achieve a better activity transition.

[0030] According to the present invention, the number of reactors in the grading method is 2 to 5.

[0031] According to the present invention, preferably, 2 to 3 types of hydrodesulfurization catalysts are loaded.

[0032] According to the present invention, the hydrodesulfurization catalyst and the hydroremoval of carbon residue catalyst are loaded according to the conventional grading principle, that is, along the logistics direction, the catalyst particle size is from large to small, the pore size is from large to small, the porosity is from large to small, and the active metal content is from low to high.

[0033] According to the present invention, the compositions of the hydrodesulfurization catalyst and the hydroremoval of carbon residue catalyst independently include: a porous oxide as a carrier, and a VIB group metal and / or a VIII group metal as an active metal component. Based on the mass of the catalyst, the active metal accounts for 15wt% to 25wt% of the oxide, and the carrier accounts for 75wt% to 85wt%. The porous oxide is preferably alumina. The VIB group metal is at least one selected from Mo and W; the VIII group metal is at least one selected from Co and Ni. Preferably, one or more of P, B, Si, F, Ti and Zr can be added as an additive.

[0034] According to the present invention, in the grading method, the loading volume ratio of the catalyst in the first reactor to the catalyst in other reactors can be set according to conventional methods, wherein the loading volume of the catalyst in the first reactor accounts for 20% to 50% of the total loading volume of the catalyst in all reactors.

[0035] According to the present invention, the catalyst in the grading method can be prepared by conventional methods in the prior art or commercial catalysts. Preferably, the first hydrodemetallization catalyst is a commercial catalyst, and the second hydrodemetallization catalyst is prepared by loading active metals on a commercial catalyst carrier.

[0036] According to the present invention, the catalyst in each reactor is generally loaded by bag-type loading or dense-phase loading, and the loading methods of the catalyst are all conventional loading methods in the art.

[0037] The second aspect of the present invention provides application of the above-mentioned hydroprocessing catalyst grading method in heavy oil hydrogenation reaction.

[0038] According to the present invention, in the application, the operating conditions of each reactor are independently: average reaction temperature 330°C to 450°C, preferably 350°C to 430°C, more preferably 360°C to 420°C; reaction hydrogen partial pressure 8.0MPa to 20.0MPa, preferably 10.0MPa to 18.0MPa, more preferably 12.0MPa to 18.0MPa; liquid hourly volume space velocity 0.15h -1 ~3.0h -1 , preferably 0.2h -1 ~2.0h -1 , more preferably 0.2h -1 ~1.2h -1 ; The volume ratio of hydrogen to oil is 300 to 1500, preferably 400 to 1300, and more preferably 500 to 1000.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. In the present invention, the hydrogenation catalyst grading method comprises at least two reactors connected in series in sequence, and the first reactor along the logistics direction is recorded as the first reactor; at least one hydrogenation protection catalyst, at least one first hydrodemetallization catalyst, and at least one second hydrodemetallization catalyst are sequentially loaded in the first reactor along the logistics direction; the particle size, pore size, porosity, and active metal content of any second hydrodemetallization catalyst are respectively greater than the particle size, pore size, porosity, and active metal content of the upstream catalyst adjacent thereto. The deactivation of the hydrogenation catalyst is mainly caused by the deposition of metal impurities and carbon deposition and coking. The residual oil hydrogenation reaction is an exothermic reaction. Along the logistics direction, the temperature of the reaction zone gradually increases, and the non-ideal components increase, and the hydrogen concentration decreases, resulting in a high temperature at the bottom of the reactor and a low hydrogen concentration. The carbon deposition reaction of the catalyst is very sensitive to temperature and hydrogen concentration, resulting in that the carbon deposition of the catalyst in the lower part of the reactor is usually more serious than that in the upper part, and the catalyst bed is prone to coking, especially for the catalyst bed with high activity and small pore size in the lower part of the reactor, the coking is more obvious. At the same time, due to the small particle size, pore size and porosity, with the continuous deposition of metal impurities, the catalyst pores are easily blocked, the catalyst deactivates quickly, and the stability is poor. In the present invention, the pore size and porosity of the second hydrodemetallization catalyst located at the lower part of the reactor are greater than the first hydrodemetallization catalyst located at the upper part of the reactor, and the loading order of the second hydrodemetallization catalyst is loaded in reverse order, the catalyst pores are not easy to be blocked, the catalyst deactivation rate is slow, and the stability is better. At the same time, compared with the conventional grading method, this section of the catalyst loads a higher metal content, so that by increasing the content of active metal components, the hydrogenation performance is improved, and the reaction activity of the entire catalyst system is fully guaranteed. The catalyst grading combination of the present invention can give full play to the role of the catalyst in the lower region of the reactor, reduce the deposition of metal impurities and carbon deposits on the catalyst, slow down the catalyst deactivation rate, improve the demetallization, desulfurization and residual carbon removal stability of the entire system, and extend the operation cycle of the catalyst.

[0041] 2. In the present invention, the grading method is suitable for heavy oil hydrogenation reaction. The grading method can reduce the deposition of metal impurities and carbon deposits on the catalyst, slow down the deactivation rate of the catalyst, improve the demetallization, desulfurization and carbon removal stability of the entire system, and extend the operation cycle of the catalyst. DETAILED DESCRIPTION

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

[0043] In the present invention, the particle size of the catalyst is measured using a vernier caliper.

[0044] In the present invention, the pore size is determined by low temperature N2 adsorption method, and the instrument is ASAP2420 type fully automatic physical adsorption instrument. The pore size is a variable pore size.

[0045] In each example of the present invention, the hydrogenation protection catalyst is FZC-11A and FZC-12B. The first hydrodemetallization catalyst is FZC-103E and FZC-201, and the second hydrodemetallization catalyst is CA-1, CA-2, and FZC-28. The hydrodemetallization catalyst is FZC-204A. The hydrodesulfurization catalyst is FZC-33. The hydrodecarbonation catalyst is FZC-41. Among the above catalysts, CA-1 and CA-2 are self-made second hydrodemetallization catalysts, and the remaining catalysts are a full range of residual oil hydrotreating catalysts developed by Dalian Petrochemical Research Institute.

[0046] In each example of the present invention, the preparation method of CA-1 is as follows: 150g of alumina carrier (FZC-28A carrier of Dalian Petrochemical Research Institute, water absorption rate 1.10mL / g, particle size 1.6mm, pore size 17.6nm, porosity 44.7%) is taken, and active metal components Mo and Ni are loaded by saturated spraying method. The spraying liquid is: 20.8g ammonium molybdate (MoO3 content is 82wt%), 16.2g nickel nitrate (NiO content is 25wt%), and 162mL ammonia solution (concentration is 15wt%). After homogenization for 10 minutes, it is dried at 120°C for 3 hours, and then calcined in air at 500°C for 3 hours to obtain a catalyst. The MoO3 content is 9.8wt% and the NiO content is 2.4wt%.

[0047] In each example of the present invention, the preparation method of CA-2 catalyst is as follows:

[0048] Take 150g of alumina carrier (FZC-103E carrier of Dalian Petrochemical Research Institute, water absorption rate 1.14mL / g, particle size 1.9mm, pore size 21.6nm, porosity 45.4%), and use saturated spraying method to load active metal components Mo and Ni. The spraying liquid is: 21.2g ammonium molybdate (MoO3 content is 82wt%), 18.8g nickel nitrate (NiO content is 25wt%), and 162mL ammonia solution (concentration is 15wt%). After homogenization for 10 minutes, dry at 120℃ for 3 hours, and then roast in air at 500℃ for 3 hours to obtain a catalyst. The MoO3 content is 10.1wt% and the NiO content is 2.8wt%.

[0049] In each example of the present invention, the second hydrodemetallization catalyst is loaded in the first reactor in such a manner that, along the direction of the flow, the particle size of the catalyst increases from small to large, the pore size increases from small to large, the porosity increases from small to large, and the active metal content increases from low to high. The particle size, pore size, porosity, and active metal component content of any second hydrodemetallization catalyst are respectively greater than the particle size, pore size, porosity, and active metal component content of the adjacent upstream catalyst.

[0050] In each example of the present invention, the test was conducted on three reactors connected in series. Along the logistics direction, there are first reactor, second reactor, and third reactor. The logistics direction in the reactor is from top to bottom. The catalyst loading volume ratio of the first reactor, second reactor, and third reactor is 30:35:35. Among them, the catalyst loading method of the second reactor and the third reactor is the same, and the catalyst loading method of the first reactor is different.

[0051] In each example of the present invention, the main physical and chemical properties of the catalyst are shown in Tables 1 to 3. The main properties of the feedstock oil for evaluating the catalyst system are listed in Table 4. The evaluation conditions of the graded catalyst are shown in Table 5. The relative removal rate evaluation results are shown in Tables 6 and 7.

[0052] Example 1

[0053] The test was conducted on a test rig with three 3-liter reactors. The catalyst loading conditions of each reactor were:

[0054] The first reactor was loaded with FZC-11A, FZC-12B, FZC-103E, FZC-201, and CA-1 from top to bottom, with a loading ratio (V) of 1:2.5:2:2.5:2; the second reactor was loaded with FZC-204A and FZC-33 from top to bottom, with a loading volume ratio of 1.5:1; the third reactor was loaded with catalyst FZC-41. The loading volume ratio of the first, second, and third reactor catalysts was 30:35:35. The main properties of the catalysts are shown in Table 1.

[0055] Table 1 Main physicochemical properties of catalysts

[0056]

[0057] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 6.

[0058] Example 2

[0059] This example shows a combined process for preparing a catalyst grading system. The test was carried out in a test device with three 3-liter reactors.

[0060] The catalyst loading conditions of each reactor are as follows:

[0061] The loading ratio (V) of the first-stage catalyst FZC-11A, FZC-12B, FZC-103E, FZC-201, and CA-1 is 1.0:2.0:2.0:2.0:3.0. The loading method of the catalysts for the second and third stages is the same as in Example 1. The loading volume ratio of the first, second, and third stages catalysts is the same as in Example 1. The main properties of the catalysts are shown in Table 1.

[0062] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 7.

[0063] Example 3

[0064] This example shows a combined process for preparing a catalyst grading system, which was tested in a test device with three 3-liter reactors.

[0065] The catalyst loading conditions of each reactor are as follows:

[0066] The catalysts FZC-11A, FZC-12B, FZC-103E, FZC-201, CA-1 and CA-2 were loaded from top to bottom in the first reactor, and the loading ratio (V) was 1:2.5:2:2.5:1:1. The loading method of the catalysts in the second reactor and the third reactor was the same as in Example 1. The loading volume ratio of the catalysts in the first reactor, the second reactor and the third reactor was the same as in Example 1. The main properties of the catalysts are shown in Table 2.

[0067] Table 2 Main physical and chemical properties of catalysts

[0068]

[0069] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 6.

[0070] Example 4

[0071] This example shows a combined process for preparing a catalyst grading system, which was tested in a test device with three 3-liter reactors.

[0072] The catalyst loading conditions of each reactor are as follows:

[0073] The catalysts FZC-11A, FZC-12B, FZC-103E, FZC-201, CA-1 and CA-2 were loaded from top to bottom in the first reactor, and the loading ratio (V) was 1.0:2.0:2.0:2.0:2.0:1.0. The loading method of the catalysts in the second reactor and the third reactor was the same as in Example 1. The loading volume ratio of the catalysts in the first reactor, the second reactor and the third reactor was the same as in Example 1. The main properties of the catalysts are shown in Table 2.

[0074] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 7.

[0075] Comparative Example 1

[0076] The tests were carried out in a pilot plant with three 3-liter reactors.

[0077] The catalyst loading conditions of each reactor are as follows:

[0078] The loading ratio (V) of FZC-11A, FZC-12B, FZC-103E, FZC-201 and FZC-28 in the first reactor from top to bottom is 1:2.5:2:2.5:2; the loading method of the catalyst in the second and third reactors is the same as that in Example 1. The loading volume ratio of the catalyst in the first, second and third reactors is the same as that in Example 1. The main properties of the catalyst are shown in Table 3.

[0079] Table 3 Main physicochemical properties of catalysts

[0080]

[0081] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 6.

[0082] Comparative Example 2

[0083] This example shows a combined process for preparing a catalyst grading system. The test was carried out in a test device with three 3-liter reactors.

[0084] The catalyst loading conditions of each reactor are as follows:

[0085] The loading ratio (V) of the first-stage catalyst FZC-11A, FZC-12B, FZC-103E, FZC-201, and FZC-28 is 1.0:2.0:2.0:2.0:3.0; the loading method of the second-stage and third-stage catalysts is the same as in Example 1. The loading volume ratio of the first-stage, second-stage, and third-stage catalysts is the same as in Example 1. The main properties of the catalysts are shown in Table 3.

[0086] The application of the above hydroprocessing catalyst grading method in the residual oil hydrogenation reaction was evaluated. The test results of 400 hours, 1000 hours and 3000 hours of stable operation with residual oil are shown in Table 7.

[0087] Table 4 Raw oil properties

[0088] Raw oil properties Slag in the sand <![CDATA[Density (20 °C) / kg·m -3 > 983.5 <![CDATA[Ni+V / μg·g -1 ]]> 108.8 S,wt% 3.3 CCR, wt% 14.5

[0089] Table 5 Hydrogenation operating conditions for each example

[0090] One counter Second anti Three anti Average reaction temperature, °C 370 375 385 Reaction hydrogen partial pressure, MPa 15.7 15.7 15.7 <![CDATA[Liquid hourly space velocity, h -1 > 0.22 0.22 0.22 Hydrogen to oil volume ratio 850 850 850

[0091] Table 6 Comparison of reaction performance between examples and comparative examples

[0092]

[0093] Table 7 Comparison of reaction performance between examples and comparative examples

[0094]

[0095] It can be seen from Table 4 that the initial activity of the catalysts of Examples 1, 3 and Comparative Example 1 at 400h is roughly equivalent. With the extension of the operation time, the demetallization rate and residual carbon removal rate of Examples 1 and 3 are higher than those of the comparative catalyst combination; and the attenuation degree of the removal rate is less than that of the comparative example. The desulfurization rate is roughly equivalent to that of the comparative example. In comparison, the initial reaction performance of Example 3 at 400h is slightly lower than that of Example 1, but the mid-term reaction performance at 3000h is better than that of Example 1.

[0096] It can be seen from Table 5 that the reaction performance of Example 2 and Example 4 shows similar rules to the combination of Example 1 and Example 3 given in Table 4. The initial catalyst activity of Examples 2 and 4 at 400h is roughly equivalent to that of Comparative Example 2. With the extension of operation time, the demetallization rate and residual carbon removal rate of Examples 2 and 4 are higher than those of the catalyst combination of Comparative Example 2; and the degree of attenuation of the removal rate is less than that of the Comparative Example. The desulfurization rate is roughly equivalent to that of the Comparative Example. In comparison, the initial reaction performance of Example 4 at 400h is slightly lower than that of Example 2, but the mid-term reaction performance of 3000h is better than that of Example 2. In general, the catalyst combination method of the present invention improves the stability of the entire system.

Claims

1. A grading method for a heavy oil hydroprocessing catalyst, comprising at least two reactors connected in series, the first reactor along the logistics direction being referred to as the first reactor; at least one hydrogenation protection catalyst, at least one first hydrodemetallization catalyst, and at least one second hydrodemetallization catalyst being sequentially loaded into the first reactor along the logistics direction; the particle size, pore size, porosity, and active metal content of any second hydrodemetallization catalyst are respectively greater than the particle size, pore size, porosity, and active metal content of the upstream catalyst adjacent thereto; The second hydrodemetallization catalyst is loaded in reverse order; The active metals in the second hydrodemetallization catalyst include Mo and Ni; the active metals in the first hydrodemetallization catalyst adjacent to the second hydrodemetallization catalyst include Mo and Ni; The composition of the first hydrodemetallization catalyst includes, based on the mass of the first hydrodemetallization catalyst, 88wt% to 95wt% of aluminum oxide, 3.8wt% to 10wt% of Mo in terms of oxide, and 1.2wt% to 2wt% of Ni; the composition of the second hydrodemetallization catalyst includes, based on the mass of the second hydrodemetallization catalyst, 84wt% to 92wt% of aluminum oxide, 6.5wt% to 13.5wt% of Mo in terms of oxide, and 1.5wt% to 3.5wt% of Ni; In terms of oxides, the weight content of Mo in any second hydrodemetallization catalyst is 0.3 to 4 percentage points higher than that in its adjacent upstream catalyst, and the weight content of Ni is 0.4 to 2.0 percentage points higher.

2. The grading method according to claim 1, characterized in that: Based on the total volume of the catalyst in the first reactor, the hydrogenation protection catalyst accounts for 10% to 60% of the volume; and / or, the first hydrodemetallization catalyst accounts for 10% to 50% of the volume; And / or, the second hydrodemetallization catalyst accounts for 10% to 50% of the volume.

3. The grading method according to claim 2, characterized in that: Based on the total volume of the catalyst in the first reactor, the hydrogenation protection catalyst accounts for 20% to 50% of the volume; and / or, the first hydrodemetallization catalyst accounts for 30% to 50% of the volume; And / or, the second hydrodemetallization catalyst accounts for 20% to 30% by volume.

4. The grading method according to claim 1, characterized in that: The number of the second hydrodemetallization catalysts is 2 to 4.

5. The grading method according to claim 1, characterized in that: The composition of the first hydrodemetallization catalyst includes: a porous oxide as a carrier, a VIB group metal and / or a VIII group metal as an active metal component; based on the mass of the first hydrodemetallization catalyst, the content of the active metal in the oxide is 5wt% to 12wt%, and the content of the carrier is 88wt% to 95wt%; The composition of the second hydrodemetallization catalyst includes: a porous oxide as a carrier and a VIB group metal and / or a VIII group metal as an active metal component; based on the mass of the second hydrodemetallization catalyst, the content of the active metal in the oxide is 8wt%~16wt%, and the content of the carrier is 84wt%~92wt%.

6. The grading method according to claim 1, characterized in that: The active metal weight content of any second hydrodemetallization catalyst is 0.7 to 6.0 percentage points higher than the active metal weight content of the adjacent upstream catalyst, calculated as oxides.

7. The grading method according to claim 1, characterized in that: The Mo weight content of any second hydrodemetallization catalyst is 0.3 to 3 percentage points higher than that of its adjacent upstream catalyst, and the Ni weight content is 0.4 to 1.5 percentage points higher.

8. The grading method according to any one of claims 1 to 7, characterized in that: The particle size of any second hydrodemetallization catalyst is larger than the particle size of its adjacent upstream catalyst.

9. The grading method according to claim 8, characterized in that: In the second hydrodemetallization catalyst, the particle sizes of two adjacent catalysts differ by at least 0.3 mm.

10. The grading method according to claim 9, characterized in that: In the second hydrodemetallization catalyst, the particle sizes of two adjacent catalysts differ by 0.3-1.0 mm.

11. The grading method according to any one of claims 1 to 7, characterized in that: The pore size of any second hydrodemetallization catalyst is larger than the pore size of its adjacent upstream catalyst.

12. The grading method according to claim 11, characterized in that: In the second hydrodemetallization catalyst, the pore sizes of two adjacent catalysts differ by at least 1.5 nm.

13. The grading method according to claim 12, characterized in that: In the second hydrodemetallization catalyst, the pore sizes of two adjacent catalysts differ by 1.5 nm to 5.0 nm.

14. The grading method according to any one of claims 1 to 7, characterized in that: The porosity of any second hydrodemetallization catalyst is greater than the porosity of its adjacent upstream catalyst.

15. The grading method according to claim 14, characterized in that: In the second hydrodemetallization catalyst, the porosity of two adjacent catalysts differs by at least 0.3 percentage points.

16. The grading method according to claim 15, characterized in that: In the second hydrodemetallization catalyst, the porosity of two adjacent catalysts differed by 0.5 to 3 percentage points.

17. The grading method according to claim 1, characterized in that: The particle size of the first hydrodemetallization catalyst is 1.0-2.5 mm, the pore size is 10-30 nm, and the porosity is 42.0%-46.0%.

18. The grading method according to claim 1, characterized in that: The particle size of the second hydrodemetallization catalyst is 1.5-2.7 mm, the pore size is 15-33 nm, and the porosity is 44.0%-47.0%.

19. Use of the grading method according to any one of claims 1 to 18 in heavy oil hydrogenation reaction.

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