Hydrodenitrogenation catalysts, preparation and use

Abstract

The application discloses a kind of hydrodenitrogenation catalyst and its preparation method and application.The catalyst includes carrier and active component, the active component includes Mo and Zn and / or Cu, the content of Mo is 6%-16% based on the total weight of catalyst, the content of Zn and / or Cu is 0.5%-4.5%, the mass ratio of Mo and S is above 1.5.The hydrodenitrogenation catalyst of the application not only has good hydrodenitrogenation activity when processing low-sulfur heavy residual oil feedstock, but also has good activity stability, and is particularly suitable for processing ebullated bed hydrogenation tail oil.

Description

Technical Field

[0001] This invention belongs to the field of heavy residue oil hydrotreating technology, and specifically relates to a hydrodenitrification catalyst, its preparation method, and its application in treating fluidized bed hydrotreating tail oil. Background Technology

[0002] Currently, the active phase of hydrogenation catalysts used in the petrochemical industry is a nano-scale cluster with Mo(W)S2 as the main body and Ni or Co modified on the outer layer. A key characteristic of these catalysts is their high requirement for the sulfur content of the raw materials and the reaction atmosphere. When the sulfur content in the raw materials is low, the hydrogen sulfide in the reaction system is insufficient to maintain the stable structure of the active phase, which will be reduced by hydrogen, resulting in a decrease in reaction activity.

[0003] To adapt to low-sulfur feedstocks, researchers have proposed various methods to maintain the stability of sulfur in the active phase.

[0004] CN1488729A discloses a two-stage hydrotreating process for dearomatics removal from distillate oil. This method employs a two-stage hydrotreating process, with both reactors using non-precious metal catalysts. A switching pipeline is installed between the inlet and outlet of the two reactors. When the catalyst activity in the second reactor decreases, a switching operation is performed: the original second reactor becomes the first reactor, and the original first reactor becomes the second reactor. This method solves the problem of easy catalyst deactivation in the second stage of the two-stage hydrotreating process for distillate oil using non-precious metal catalysts, and extends the catalyst operating cycle.

[0005] CN102465014B discloses a hydrocracking method for processing low-sulfur feedstock. The method includes: hydrotreating a high-sulfur feedstock, performing gas-liquid separation on the reaction effluent to obtain a sulfur-containing, hydrogen-rich gas; hydrocracking a low-sulfur feedstock oil, performing gas-liquid separation on the reaction effluent to obtain a sulfur-lean, hydrogen-rich gas; mixing the sulfur-containing, hydrogen-rich gas with the sulfur-lean, hydrogen-rich gas, selectively removing hydrogen sulfide, and then recycling it back to the reactor inlet. This method effectively combines the two hydrogen-rich gas streams from the hydrotreating and hydrocracking processes, fully utilizing the sulfur-containing, hydrogen-rich gas from the hydrotreating process to replenish sulfur in the low-sulfur feedstock hydrocracking unit, effectively solving the catalyst sulfur loss problem during long-term operation of the low-sulfur hydrocracking unit.

[0006] CN105749933B discloses a method for preparing a hydrogenation catalyst. The hydrogenation catalyst comprises a support and an active metal component supported on the support. The active metal component is distributed in a double layer along the radial direction of the support. The core layer of active metal component is NiO and WO3, and the shell layer of active metal component is MoO3, NiO, and / or CoO. The method includes the following steps: immersing a hydrothermally treated support in an acidic solution containing molybdenum compounds, nickel compounds, and / or cobalt compounds, and then drying it to obtain a support; immersing the support in an alkaline solution containing nickel compounds and tungsten compounds, and then drying and calcining it to obtain the catalyst. This catalyst utilizes the layered distribution of the active metal component on the support to improve the catalyst's hydrodesulfurization, decarbonization, and denitrification activity; however, it still suffers from poor stability when processing low-sulfur feedstocks. Summary of the Invention

[0007] To address the shortcomings of existing technologies and improve the stability of hydrotreating catalysts in low-sulfur environments, this invention proposes a heavy oil hydrodenitrification catalyst, its preparation method, and its application. When used to process low-sulfur heavy residue oil feedstock, this heavy oil hydrodenitrification catalyst exhibits not only excellent hydrodenitrification activity but also good activity stability, making it particularly suitable for processing fluidized bed hydrotreating tail oil.

[0008] The first aspect of the present invention provides a hydrodenitrification catalyst, comprising a support and an active component, wherein the active component comprises Mo and Zn and / or Cu, and based on the total weight of the catalyst, the content of Mo is 6%-16%, the content of Zn and / or Cu is 0.5%-4.5%, and the mass ratio of Mo to S is greater than 1.5.

[0009] Furthermore, the Zn and / or Cu content refers to the total content of Zn and Cu. If it contains only Zn and no Cu, it refers to the Zn content; if it contains only Cu and no Zn, it refers to the Cu content.

[0010] Furthermore, the hydrodenitrification catalyst includes a support, an active component, and an S element, wherein the active component is Mo, Zn, and / or Cu.

[0011] In existing technologies, the sulfur content in sulfurized hydrodenitrification catalysts is generally above 10 wt%. However, the active component of this invention uses Mo in combination with Zn and / or Cu, and controls the sulfur content in the catalyst to a low level, which is beneficial to improving the hydrodenitrification capacity of the catalyst and preventing the loss of sulfur in the active phase under low sulfur reaction environment.

[0012] Furthermore, in the hydrodenitrification catalyst, the mass ratio of Mo to S is preferably 1.5-3.0, more preferably 1.6-2.4. In the prior art, the mass ratio of Mo to S is generally less than 1.5, typically between 1 and 1.3. The inventors have discovered that using the catalyst of this invention, especially when the mass ratio of Mo to S is above 1.5, can improve the hydrodenitrification capacity of the catalyst and prevent the loss of sulfur in the active phase under low-sulfur reaction conditions.

[0013] Furthermore, based on the weight of the catalyst, the support content is 75%-92%, preferably 75%-91%, and the content of Mo, S, and Zn and / or Cu is 8%-25%, preferably 9%-25%.

[0014] Furthermore, XPS testing revealed that the catalyst contains Mo with valences of +2, 0, and +4, wherein +2-valent Mo accounts for 50%-70% of the total Mo atoms, 0-valent Mo accounts for 10%-30% of the total Mo atoms, and +4-valent Mo accounts for 1%-25% of the total Mo atoms; preferably, +2-valent Mo accounts for 50%-65% of the total Mo atoms, 0-valent Mo accounts for 15%-27% of the total Mo atoms, and +4-valent Mo accounts for 8%-25% of the total Mo atoms. The inventors of this invention have discovered that by controlling the proportions of different valence states of Mo in the active metal phase, especially by ensuring that +2-valent and 0-valent Mo exist in the catalyst at specific ratios, it is more beneficial for Mo to combine with Zn and / or Cu and S to form the active metal phase, and it is also more beneficial to prevent the loss of sulfur in the active phase under low-sulfur reaction conditions.

[0015] Furthermore, the sum of +4 valence Mo, +2 valence Mo, and 0 valence Mo accounts for more than 90% of the total Mo atoms, preferably 90%-99%. The catalyst provided by this invention may also contain +5 or +6 valence Mo in addition to +2 valence Mo, 0 valence Mo, and +4 valence Mo.

[0016] Furthermore, the present invention does not particularly limit the carrier, and it can be any carrier conventionally used in the art, a commercially available product, or prepared by any method in the prior art. For example, the carrier can be an inorganic refractory oxide. Preferably, the carrier is one or more of alumina, silicon oxide, and amorphous aluminum silicate. Considering both cost and effect, alumina is preferred as the carrier. The carrier may contain one or more of modifying elements such as phosphorus, silicon, boron, fluorine, magnesium, and sodium. The amount of the modifying element added is conventional, preferably 0.2%-3.0% of the carrier mass.

[0017] Furthermore, the carrier has the following properties: specific surface area of ​​230-400 m². 2 / g, preferably 250-360m 2 / g, pore volume 0.4-1.1cm 3 / g, preferably 0.6-1.0cm 3 / g.

[0018] A second aspect of the present invention provides a method for preparing the above-mentioned catalyst, comprising:

[0019] (1) A catalyst precursor I was obtained by introducing molybdenum hexacarbonyl and organic compounds containing Zn and / or Cu into a support by impregnation.

[0020] (2) In the presence of an inert gas, the dispersant is contacted with the catalyst precursor I to obtain catalyst precursor II;

[0021] (3) Using at least one of steps (3-1) or (3-2), wherein,

[0022] Step (3-1) includes sulfiding the catalyst precursor II, wherein the sulfidation results in a Mo to S mass ratio of 1.5 or more, preferably 1.5-3.0, and more preferably 1.6-2.4, based on the total weight of the catalyst in the prepared hydrodenitrification catalyst.

[0023] Step (3-2) involves impregnating catalyst precursor II with an impregnation solution containing polysulfide compounds, followed by drying.

[0024] Further, in step (1), there is no particular limitation on the impregnation method; it can be equal-volume impregnation or excessive impregnation. In this invention, the hexacarbonylmolybdenum and the organic compound containing Zn and / or Cu can be introduced into the support simultaneously through co-impregnation or separately through stepwise impregnation; there is no particular limitation on the order of introduction. When the organic compound containing Zn and / or Cu includes two or more, it can also be introduced into the support simultaneously through co-impregnation or separately through stepwise impregnation. According to this invention, it is preferred that the hexacarbonylmolybdenum and the organic compound containing Zn and / or Cu are introduced through co-impregnation.

[0025] Further, step (1) preferably includes: impregnating the carrier with an impregnation solution containing molybdenum hexacarbonyl and an organic compound containing Zn and / or Cu, followed by drying; preferably, the impregnation is an equal-volume impregnation method or an excess impregnation method. The drying conditions are subject to a wide range of selection, as long as the solvent is removed without causing the evaporation of molybdenum hexacarbonyl and the organic compound containing Zn and / or Cu.

[0026] Further, in step (1), preferably, the drying is vacuum drying under reduced pressure. More preferably, the drying conditions include: a drying temperature of 60-120℃, preferably 80-100℃, a drying vacuum degree of 0.1-2 torr, preferably 0.2-1 torr, and a drying time of 1-10 hours, preferably 2-8 hours.

[0027] Further, in step (1), the solvent in the impregnation solution is preferably one or more of ethanol, benzene, toluene, xylene, ethylbenzene, and tetrahydronaphthalene, more preferably at least one of toluene, xylene, ethylbenzene, and tetrahydronaphthalene, and optionally ethanol. Preferably, the organozinc compound is selected from one or more of zinc propionate, zinc octanoate, zinc p-toluenesulfonate, and zinc fumarate. The organocopper compound is selected from at least one of copper propionate, copper naphthenate, copper citrate, copper acetylacetonate, and copper lactate.

[0028] Further, in the impregnation solution described in step (1), the concentration of molybdenum hexacarbonyl is 0.2-2.5 mol / L, preferably 0.3-2.0 mol / L.

[0029] Further, in the impregnation solution of step (1), the concentration of the organozinc compound and / or organocopper compound is 0.02-0.9 mol / L, preferably 0.05-0.8 mol / L. Wherein, the concentration of the organozinc compound and / or organocopper compound is the sum of the concentrations of the organozinc compound and organocopper compound in the impregnation solution.

[0030] Further, in step (1), the support is a conventional residue hydrodenitrification catalyst support, which can be selected from one or more of alumina, silica, and amorphous silica-alumina. The properties of the support are as follows: specific surface area of ​​230-400 m². 2 / g, preferably 250-360m 2 / g, pore volume 0.4-1.1cm 3 / g, preferably 0.6-1.0cm 3 / g. The carrier may be doped with one or more modifying elements such as phosphorus, silicon, boron, fluorine, magnesium, and sodium. The amount of the modifying element added is conventional, preferably 0.2%-3.0% of the carrier mass.

[0031] Furthermore, the amounts of the support, molybdenum hexacarbonyl, and organozinc and / or organocopper compounds are such that, based on the total weight of the catalyst, the prepared hydrodenitrification catalyst contains 6%-16% Mo and 0.5%-4.5% Zn and / or Cu. Those skilled in the art can appropriately select the amount and concentration of the impregnation solution based on the above disclosure.

[0032] Furthermore, in step (2), the inert gas is preferably one or more of nitrogen, argon, helium and neon.

[0033] Furthermore, in step (2), contacting the dispersant with the catalyst precursor I yields a stable organic molybdenum dimer, which is more conducive to the subsequent formation of a highly dispersed active phase. There are no particular limitations on the method of contacting the dispersant with the catalyst precursor I; it can be done continuously or intermittently. The dispersant can be introduced in gaseous or liquid form; this invention does not impose any particular limitation on this.

[0034] Furthermore, in step (2), the type of dispersant is selected from a wide range, as long as it can contact the catalyst precursor I to obtain a stable organic molybdenum dimer. Preferably, the dispersant is selected from at least one of acetic acid, acetic anhydride, citric acid, dimethyl malonate, malonic acid, and succinic acid; more preferably, the dispersant is acetic acid and / or acetic anhydride.

[0035] Further, in a preferred case, in step (2), the amount of dispersant used is 1 to 10 g relative to 1 g of the catalyst precursor I, preferably 2 to 5 g.

[0036] Further, preferably, the contact conditions in step (2) include: a pressure of 0–1 MPa, preferably 0.1–0.5 MPa, a temperature of 80–180°C, preferably 100–150°C, and a time of 8–36 hours, preferably 12–24 hours. Wherein, the pressure is gauge pressure.

[0037] Further, preferably, the method further includes removing the remaining dispersant after the contact described in step (2) by evaporation drying, preferably by vacuum drying under reduced pressure. The drying conditions are selected within a wide range, as long as they are sufficient to remove the solvent without causing significant loss of the loaded organomolybdenum species, organozinc metal compounds, and / or organocalcohol metal compounds from the carrier surface. Preferably, the evaporation drying conditions include: a drying temperature of 80–150°C, preferably 100–120°C; a drying vacuum of 0.1–2 torr, preferably 0.2–1 torr; and a drying time of 1–8 hours, preferably 2–6 hours.

[0038] Furthermore, the contact described in step (2) can be carried out in a reactor, such as an autoclave, preferably under closed conditions.

[0039] Further, the dispersant and the catalyst precursor I are placed in a reaction vessel, sealed, and inert gas is introduced to the contact pressure. The mixture is then heated to the contact temperature and kept at a constant temperature. The method also includes cooling the catalyst precursor obtained in step (2) and then subjecting it to vacuum drying under reduced pressure.

[0040] Furthermore, there are no particular limitations on the sulfidation process described in step (3-1), and conventional methods in the art can be used. Known sulfidation methods can be employed, and preferably, the sulfidation includes dry sulfidation and / or wet sulfidation. The dry sulfidation and wet sulfidation methods described in this invention have their conventional interpretations in the art. There are no particular limitations on the conditions for dry sulfidation and wet sulfidation, as long as the mass ratio of Mo to S in the hydrogenation catalyst is 1.5 or higher (preferably 1.5 to 3.0, more preferably 1.6 to 2.4).

[0041] Furthermore, it is preferable to treat catalyst precursor II using step (3-2), which is more conducive to obtaining a catalyst with better hydrogenation processing capability.

[0042] Furthermore, the specific implementation of the impregnation method in step (3-2) can be as described above, and will not be repeated here. Preferably, the impregnation method in step (3-2) is an equal-volume impregnation.

[0043] Further, in step (3), the solvent in the impregnation solution containing polysulfide compounds is at least one of C5-C10 alkanes and / or cycloalkanes and aromatics, preferably one or more of cyclohexane, n-heptane, n-octane, tetrahydronaphthalene, decahydronaphthalene, toluene, and xylene.

[0044] Further, in step (3), the polysulfide compound refers to a compound containing at least 2 moles of sulfur per mole, for example, 2-3 moles. The polysulfide compound is preferably one or more of di-tert-butyl polysulfide (preferably 2-3 moles of sulfur), tert-nonyl polysulfide (preferably 2-3 moles of sulfur), tert-dodecyl polysulfide (preferably 2-3 moles of sulfur), and dihexanedisulfide.

[0045] Furthermore, the di-tert-butyl polysulfides include, but are not limited to, di-tert-butyl disulfide and di-tert-butyl trisulfide.

[0046] Furthermore, the tert-nonyl polysulfides include, but are not limited to, tert-nonyl dimersulfides and tert-nonyl trimersulfides.

[0047] Furthermore, the tert-dodecyl polysulfides include, but are not limited to, tert-dodecyl trimersulfides and tert-dodecyl dimersulfides.

[0048] Furthermore, the dihexanedisulfide includes, but is not limited to, n-dihexanedisulfide and tert-dihexanedisulfide.

[0049] Furthermore, in the impregnation solution containing polysulfides, the mass concentration of polysulfides is 2%-20%, preferably 3%-15%.

[0050] Further, preferably, the amount of the impregnation solution containing polysulfide compounds and the catalyst precursor II is such that the mass ratio of Mo to S in the prepared hydrogenation catalyst is 1.5 or more, preferably 1.5 to 3.0, and more preferably 1.6 to 2.4.

[0051] Further, in step (3-2), preferably, the method further includes drying after the impregnation. Preferably, the drying is vacuum drying under reduced pressure. More preferably, the drying conditions include: a drying temperature of 60-120°C, preferably 80-100°C; a vacuum degree of 0.1-2.0 torr, preferably 0.2-1.0 torr; and a drying time of 1-6 hours, preferably 2-4 hours.

[0052] Furthermore, the material obtained from drying in step (3-2) can be used directly as a product, and can be treated with hydrogen before use. Alternatively, the material obtained from drying in step (3-2) can be treated with hydrogen and then used directly. It is understood that the methods before and after hydrogen treatment and the resulting products are all within the scope of protection of this invention.

[0053] Furthermore, preferably, step (3-2) further includes hydrogen treatment of the dried material.

[0054] Further, preferably, in step (3-2), the hydrogen treatment is carried out in a hydrogen atmosphere provided by a hydrogen-containing gas.

[0055] Further, preferably, the hydrogen-containing gas contains hydrogen and an inert gas. The range of types of inert gas selected is as described above, and will not be repeated here.

[0056] Further, preferably, the hydrogen content in the hydrogen-containing gas is not less than 50% v, preferably 50-100% v, and more preferably 100% v.

[0057] Further, preferably, the hydrogen gas is passed through in a single pass during the hydrogen treatment process. More preferably, the amount of hydrogen used is 0.1 to 1 NL relative to 1 g of the dried material, preferably 0.2 to 0.8 NL.

[0058] Furthermore, the hydrogen treatment is carried out under closed conditions, for example, in a reaction vessel.

[0059] Further, preferably, the conditions for hydrogen treatment include: a hydrogen treatment temperature of 180–300°C, preferably 200–260°C, and a treatment time of 2–10 hours, preferably 3–6 hours.

[0060] Furthermore, after hydrogen treatment in step (3-2), the process may also include cooling, inert gas replacement, and other processes.

[0061] The third aspect of this invention provides the application of the above-mentioned catalyst in the hydrodenitrification reaction of low-sulfur heavy feedstock.

[0062] Further, the low-sulfur heavy feedstock is at least one selected from fluidized bed hydrotreated tail oil, coal tar, and Fischer-Tropsch synthesis oil, more preferably fluidized bed hydrotreated tail oil. The density of the low-sulfur heavy feedstock is 0.95–1.05 g / cm³. 3 The sulfur content is below 8000 ppm, which can be 1500-7000 ppm; the nitrogen content is below 5000 ppm, which can be 500-5000 ppm; and the residual carbon content is 8%-25%.

[0063] Furthermore, the hydrodenitrification reaction conditions are as follows: reaction temperature 300-450℃, reaction pressure 12-25MPa, hydrogen-to-oil volume ratio 500-2000:1, and liquid hourly space velocity 0.1-0.5h⁻¹. -1 .

[0064] Compared with the prior art, the present invention has the following advantages:

[0065] 1. In conventional hydrogenation catalysts, the active metals are typically Mo and Ni(Co), with the active phase being predominantly MoS2 (+4 valence Mo) and Ni(Co) distributed around MoS2. The inventors of this invention have discovered that by controlling the proportions of different valence states of Mo in the active metal phase, especially ensuring that +2 valence Mo and 0 valence Mo exist in a specific ratio within the catalyst, Mo can combine with Zn and / or Cu, as well as S, to form a metallic active phase. This results in a tighter bond between Mo and sulfur, and a stronger interaction between Zn and / or Cu and sulfur, thus preventing the loss of sulfur from the active phase in a low-sulfur reaction environment. Furthermore, by adjusting the electron distribution on the main crystal plane of the active metal phase through Zn and / or Cu, the orbital energy levels of the main crystal plane are lowered, selectively enhancing its ability to hydrogenate nitrides. This results in better denitrification activity when used to process high-nitrogen feedstocks. Therefore, the catalyst of this invention exhibits better denitrification activity and stability when used to process low-sulfur, high-nitrogen feedstocks.

[0066] 2. In the preparation method of the catalyst of the present invention, low-valence organic molybdenum and organic zinc sources and / or organic copper sources are used to introduce zinc and / or copper and molybdenum species into the catalyst, so as to achieve uniform mixing of molybdenum, zinc and / or copper on the catalyst surface. The molybdenum source is then treated with acetic acid and / or acetic anhydride as a dispersant to obtain dimolybdenum tetraacetate monomer. In this monomer, molybdenum atoms are linked by Mo-Mo chemical bonds. Compared with conventional molybdenum oxide species, the molybdenum interatomic distance in the dimolybdenum tetraacetate monomer is smaller and the coordination number is lower, which is beneficial to the formation of low-valence molybdenum sulfide species during the sulfidation process. Finally, polysulfides are used as sulfur sources to treat the dimolybdenum tetraacetate monomer. Due to the limited sulfur content and the low valence of molybdenum, as well as the electron-donating effect of zinc, the valence of molybdenum in the prepared catalyst is mainly 0 and +2.

[0067] 3. The method provided by this invention is particularly suitable for hydrotreating fluidized bed hydrotreating tail oil. Unlike straight-run residue, fluidized bed hydrotreating tail oil is residue after fluidized bed hydrotreating. Although it has lower sulfur, nitrogen, and aromatic hydrocarbon content, the nitrogen atoms in the remaining nitrogen compounds are often protected by numerous condensed aromatic rings, making them more difficult to approach and remove from the catalyst's active site, further increasing the difficulty of hydroremoval. When the hydrotreating method of this invention is used to treat fluidized bed hydrotreating tail oil, it ensures the full utilization of hydroremoval carbon and nitrogen removal activity under low-sulfur conditions, and also improves the stability of the hydrotreating process. Detailed Implementation

[0068] The present invention will be further described below with reference to embodiments, but it should be understood that the scope of protection of the present invention is not limited to the embodiments. In the present invention, unless otherwise expressly stated, percentages and contents are all expressed by mass.

[0069] In this invention, the contents of Mo, Zn and / or Cu, and S in the hydrodenitrification catalyst can be determined by ICP using an OPTIMA 7000DV atomic emission spectrometer manufactured by PE Corporation. 0.1 g of the sample is dissolved in a mixed solution with a volume ratio of 3HCl:1HNO3:0.5HF. The mixed solution is then diluted with deionized water to a specific volume, ensuring the content of the analyte element in the solution is between 1 and 10 ppm, before measurement.

[0070] In this invention, the XPS operating conditions are as follows: light source: Mg Kα, energy step: 0.05 eV, scan range: 200-250 eV (molybdenum), 280-300 eV (carbon). When analyzing the valence state of molybdenum, molybdenum species with a 3d5 / 2 orbital binding energy of 227-228 eV are considered to have a valence of 0; those with a valence between 228-229 eV are considered to have a valence of +2; those with a valence between 229-231 eV are considered to have a valence of +4; and those with a valence greater than 231 eV are considered to have a valence of +5 or +6.

[0071] The carriers used in the following embodiments and comparative examples of this invention were prepared by the following methods:

[0072] Weigh 1000.0g of alumina dry adhesive powder, add 20.0g of succinic acid and 10.0g of guar gum powder, mix well, then add 1000.0g of an aqueous solution containing 3.0% nitric acid by mass. After rolling for 10.0min, extrude the mixture using a clover-shaped perforated plate with a diameter of 1.8mm. Dry at 140℃ for 4.0h, then calcine at 550℃ for 4.0h. The carrier, after calcination and shaping to a length of 3-5mm, is designated S-0. The carrier properties are as follows: specific surface area of ​​315m². 2 / g, pore volume 0.82cm 3 / g.

[0073] Example 1

[0074] Take 20.0g of molybdenum hexacarbonyl and 7.3g of zinc octanoate, and prepare solution MQ-1 with 120g of toluene.

[0075] Take 100.0g of S-0, impregnate it with MQ-1, and then dry it under reduced pressure at a temperature of 100℃ and a vacuum of 0.5 torr for 6.0 hours. The resulting catalyst precursor is denoted as P-1.

[0076] P-1 was placed in a high-pressure reactor, along with 300.0 g of acetic acid. After sealing, nitrogen gas at 0.2 MPa was introduced, and the mixture was heated to 100°C and kept at that temperature for 24 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 110°C and a vacuum of 0.3 torr for 4.0 hours. The resulting catalyst precursor was denoted as Y-1.

[0077] 10g of di-tert-butyl trimersulfide was mixed with 80.0g of toluene to prepare solution SQ-1. Y-1 was impregnated with SQ-1, and then the catalyst was dried under reduced pressure at a temperature of 90℃ and a vacuum degree of 0.3 torr for 4.0 hours. The resulting catalyst precursor was denoted as SY-1.

[0078] Take 50.0g of SY-1 and put it into a reaction vessel. Under closed conditions, introduce 30.0NL of hydrogen gas and control the reaction temperature at 200℃. React for 4.0 hours. After cooling, replace with nitrogen gas. The resulting catalyst is denoted as Cat-1.

[0079] Example 2

[0080] Take 30.0g of molybdenum hexacarbonyl and 15.0g of zinc propionate, and prepare solution MQ-2 with 120g of xylene.

[0081] Take 100.0g of S-0, impregnate it with MQ-2, and then dry it under reduced pressure at a temperature of 110℃, a vacuum degree of 0.3 torr, and a drying time of 5.0 hours. The resulting catalyst precursor is denoted as P-2.

[0082] P-2 was placed in a high-pressure reactor, along with 240.0 g of acetic acid. After sealing, nitrogen gas at 0.3 MPa was introduced, and the mixture was heated to 120°C and kept at that temperature for 24 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 110°C and a vacuum of 0.2 torr for 4.0 hours. The resulting catalyst precursor was denoted as Y-2.

[0083] 10g of tert-nonyl trimerium sulfide and 80.0g of tetrahydronaphthalene were mixed to prepare solution SQ-2. Y-2 was impregnated with SQ-2, and then the catalyst was dried under reduced pressure at a temperature of 100℃ and a vacuum of 0.2 torr for 4.0 hours. The resulting catalyst precursor was denoted as SY-2.

[0084] Take 50.0g of SY-2 and put it into a reaction vessel. Under closed conditions, introduce 35.0NL of hydrogen gas and control the reaction temperature at 220℃. React for 4.0 hours. After cooling, replace with nitrogen gas. The resulting catalyst is denoted as Cat-2.

[0085] Example 3

[0086] Take 40.0g of molybdenum hexacarbonyl and 20.0g of zinc lactate, and prepare solution MQ-3 with 120g of ethylbenzene.

[0087] Take 100.0g of S-0, impregnate it with MQ-3, and then dry it under reduced pressure at a temperature of 120℃ and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor is denoted as P-3.

[0088] P-3 was placed in a high-pressure reactor, along with 260.0 g of acetic acid. After sealing, nitrogen gas at -0.4 MPa was introduced, and the reactor was heated to 110°C and kept at that temperature for 30 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 120°C and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was denoted as Y-3.

[0089] 10g of tert-dodecyl trimersulfide and 80.0g of decahydronaphthalene were mixed to prepare solution SQ-3. Y-3 was impregnated with SQ-3, and then the catalyst was dried under reduced pressure at a temperature of 110℃ and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was designated SY-3.

[0090] Take 50.0g of SY-3 and put it into a reaction vessel. Under closed conditions, introduce 25.0NL of hydrogen gas and control the reaction temperature at 240℃. React for 3.0 hours. After cooling, replace with nitrogen gas. The resulting catalyst is denoted as Cat-3.

[0091] Example 4

[0092] Take 50.0g of molybdenum hexacarbonyl and 15.0g of zinc fumarate, and prepare solution MQ-4 with 120g of tetrahydronaphthalene.

[0093] Take 100.0g of S-0, impregnate it with MQ-4, and then dry it under reduced pressure at a temperature of 110℃ and a vacuum of 0.2 torr for 4.0 hours. The resulting catalyst precursor is denoted as P-4.

[0094] P-4 was placed in a high-pressure reactor, along with 280.0 g of acetic acid. After sealing, nitrogen gas at 0.4 MPa was introduced, and the mixture was heated to 120°C and kept at that temperature for 32 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 120°C and a vacuum of 0.2 torr for 5.0 hours. The resulting catalyst precursor was denoted as Y-4.

[0095] 10g of tert-dihexane disulfide and 80.0g of tetrahydronaphthalene were mixed to prepare solution SQ-4. Y-4 was impregnated with SQ-4, and then the catalyst was dried under reduced pressure at a temperature of 120℃ and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was denoted as SY-4.

[0096] 50.0g of SY-4 was placed in a reactor. Under sealed conditions, 20.0NL of hydrogen gas was introduced and the reaction temperature was controlled at 230℃. The reaction was carried out for 6.0 hours. After cooling, the reaction was purged with nitrogen gas. The resulting catalyst was denoted as Cat-4.

[0097] Example 5

[0098] Take 30.0g of molybdenum hexacarbonyl and 15.0g of copper propionate, and prepare solution MQ-5 with 120g of xylene.

[0099] Take 100.0g of S-0, impregnate it with MQ-5, and then dry it under reduced pressure at a temperature of 120℃, a vacuum degree of 0.3 torr, and a drying time of 5.0 hours. The resulting catalyst precursor is denoted as P-5.

[0100] P-5 was placed in a high-pressure reactor, along with 240.0 g of acetic acid. After sealing, nitrogen gas at 0.3 MPa was introduced, and the reactor was heated to 120°C and kept at that temperature for 24 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 110°C and a vacuum of 0.2 torr for 4.0 hours. The resulting catalyst precursor was denoted as Y-5.

[0101] 10g of tert-nonyl trimerium sulfide and 80.0g of tetrahydronaphthalene were mixed to prepare solution SQ-5. Y-5 was impregnated with SQ-5, and then the catalyst was dried under reduced pressure at a temperature of 100℃ and a vacuum of 0.2 torr for 4.0 hours. The resulting catalyst precursor was denoted as SY-5.

[0102] Take 50.0g of SY-5 and put it into a reaction vessel. Under closed conditions, introduce 35.0NL of hydrogen gas and control the reaction temperature at 220℃. React for 4.0 hours. After cooling, replace with nitrogen gas. The resulting catalyst is denoted as Cat-5.

[0103] Example 6

[0104] Take 40.0g of molybdenum hexacarbonyl and 20.0g of copper lactate, and prepare solution MQ-6 with 120g of ethylbenzene.

[0105] Take 100.0g of S-0, impregnate it with MQ-6, and then dry it under reduced pressure at a temperature of 120℃ and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor is denoted as P-6.

[0106] P-6 was placed in a high-pressure reactor, and 230.0 g of acetic anhydride was added. After sealing, nitrogen gas at -0.4 MPa was introduced, and the reactor was heated to 110°C and kept at that temperature for 30 hours. After cooling, the catalyst was dried under reduced pressure at a temperature of 120°C and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was denoted as Y-6.

[0107] 10g of tert-dodecyl trimersulfide and 80.0g of decahydronaphthalene were mixed to prepare solution SQ-6. Y-6 was impregnated with SQ-6, and then the catalyst was dried under reduced pressure at a temperature of 110℃ and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was designated SY-6.

[0108] 50.0g of SY-6 was placed in a reactor. Under sealed conditions, 25.0NL of hydrogen gas was introduced and the reaction temperature was controlled at 240℃. The reaction was carried out for 3.0 hours. After cooling, the reaction was purged with nitrogen gas. The resulting catalyst was named Cat-6.

[0109] Comparative Example 1

[0110] Take 30.0g of ammonium molybdate and 25.0g of zinc nitrate hexahydrate, and prepare 120mL of aqueous solution, which is denoted as DQ-1.

[0111] The catalyst obtained by impregnating 100.0g of S-0 with DQ-1, evaporating at 120℃ for 5.0 hours, and calcining at 500℃ for 5.0 hours is designated as DCT-1.

[0112] Prepare a sulfiding solution by mixing 1000.0g of cyclohexane with 50.0g of DMDS, and label it DSQ-1.

[0113] 10.0 g of DCT-1 was placed in a reaction tube, and hydrogen and DSQ-1 were introduced for sulfidation. The sulfidation temperature was 340℃, the sulfidation time was 8.0 hours, the hydrogen pressure was 5.0 MPa, the hydrogen flow rate was 150 ml / L, and the DSQ-1 flow rate was 20.0 ml / h. The sulfidated catalyst was designated DCT-S1.

[0114] Comparative Example 2

[0115] Take 30.0g of ammonium molybdate and 20.0g of nickel nitrate hexahydrate, and prepare 100mL of aqueous solution, which is denoted as DQ-2.

[0116] The catalyst obtained by impregnating 100.0g of S-0 with DQ-2, evaporating at 120℃ for 5.0 hours, and then burning at 500℃ for 5.0 hours is designated as DCT-2.

[0117] Prepare a sulfidation solution by mixing 1000.0g of cyclohexane with 50.0g of DMDS, and label it DSQ-2.

[0118] 10.0 g of DCT-2 was placed in a reaction tube, and hydrogen and DSQ-2 were introduced for sulfidation. The sulfidation temperature was 340℃, the sulfidation time was 8.0 hours, the hydrogen pressure was 5.0 MPa, the hydrogen flow rate was 150 ml / L, and the DSQ-2 flow rate was 20.0 ml / h. The sulfidated catalyst was designated DCT-S2.

[0119] Comparative Example 3

[0120] The preparation methods of catalyst precursor P-3 and sulfur-containing solution SQ-3 are the same as in Example 3.

[0121] P-3 was impregnated with SQ-3, and then the catalyst was dried under reduced pressure at a temperature of 110°C and a vacuum of 0.2 torr for 6.0 hours. The resulting catalyst precursor was denoted as DSP-3.

[0122] Take 50.0g of DSP-3 and put it into a reactor. Under closed conditions, introduce 25.0NL of hydrogen gas and control the reaction temperature at 240℃. React for 3.0 hours. After cooling, replace with nitrogen gas. The resulting catalyst is denoted as DCT-3.

[0123] Comparative Example 4

[0124] Take 30.0g of ammonium molybdate and 25.0g of copper nitrate hexahydrate, and prepare 120mL of aqueous solution, which is denoted as DQ-4.

[0125] The catalyst obtained by impregnating 100.0g of S-0 with DQ-4, evaporating at 120℃ for 5.0 hours, and calcining at 500℃ for 5.0 hours is designated as DCT-4.

[0126] Prepare a vulcanizing solution by mixing 1000.0g of cyclohexane with 50.0g of DMDS, and label it DSQ-4.

[0127] 10.0 g of DCT-4 was placed in a reaction tube, and hydrogen and DSQ-4 were introduced for sulfidation. The sulfidation temperature was 340℃, the sulfidation time was 8.0 hours, the hydrogen pressure was 5.0 MPa, the hydrogen flow rate was 150 ml / L, and the DSQ-4 flow rate was 20.0 ml / h. The sulfidated catalyst was designated DCT-S4.

[0128] Table 1 shows the elemental analysis of the catalysts obtained in each example.

[0129]

[0130]

[0131] Table 2 shows the valence state analysis results of Mo in the catalysts obtained in each example.

[0132] Catalyst number 0% Mo percentage +2 valent Mo percentage / % +4 valent Mo percentage / % Cat-1 19.0 61.3 12.4 Cat-2 20.1 57.6 18.3 Cat-3 18.6 62.7 15.1 Cat-4 20.5 62.9 10.8 Cat-5 19.4 59.8 16.8 Cat-6 21.1 60.2 15.7 DCT-S1 ＜1 1.3 79.4 DCT-S2 ＜1 2.4 77.9 DCT-3 5.9 36.7 55.0 DCT-S4 ＜1 1.1 74.3

[0133] Examples 7-12

[0134] Using fluidized bed residue hydrotreating oil as feedstock, and employing a fixed-bed hydrotreating process, hydrotreating evaluation experiments were conducted on the catalysts obtained in Examples 1-6 above. The properties of the fluidized bed residue hydrotreating oil are shown in Table 3.

[0135] Table 3 Properties of oils produced by hydrotreating fluidized bed residue oil

[0136]

[0137]

[0138] A hydroprotective agent (FZC-100B) and a hydrodemetallization catalyst (FZC-204A) were loaded before the aforementioned catalyst, with a loading volume ratio of 1:2:4 for the protective agent, the hydrodemetallization catalyst, and the catalyst obtained in the examples. The operating conditions were: reaction temperature 390°C, reaction pressure 20.0 MPa, hydrogen-to-oil volume ratio 1500:1, and liquid hourly space velocity (LHSV) 0.4 h⁻¹. -1 After 1500 hours of reaction evaluation, the residual carbon value and nitrogen content of the hydrotreated oil fraction at a temperature not lower than 300℃ were analyzed, and the results are shown in Table 4.

[0139] Comparative Examples 5-8

[0140] The hydrogenated oil from the fluidized bed residue (see Table 3) was selected as the feedstock, and a fixed-bed process was used to evaluate the activity of the catalysts obtained in Comparative Examples 1-4. A hydrotreating protectant (FZC-100B) and a hydrodemetallization catalyst (FZC-204A) were loaded before the above catalysts, with a loading volume ratio of 1:2:4 for the protectant, hydrodemetallization catalyst, and the catalysts obtained in the comparative examples. The operating conditions were: reaction temperature 390℃, reaction pressure 20.0 MPa, hydrogen-to-oil volume ratio 1500:1, and liquid hourly space velocity (LISH) 0.4 h⁻¹. -1 After 1500 hours of reaction evaluation, the residual carbon value and nitrogen content of the hydrotreated oil fraction at a temperature not lower than 300℃ were analyzed, and the results are shown in Table 4.

[0141] Table 4 Properties of Oils Generated by Fixed-Bed Hydrogenation

[0142]

[0143]

[0144] As can be seen from the evaluation results in Table 4, the catalyst of the present invention has good hydrodenitrification and hydrodecarbonization activity and good stability when hydrotreating low-sulfur fluidized bed residue oil to produce oil.

Claims

1. A hydrodenitrogenation catalyst comprising a support and an active component, the active component comprising Mo and Zn and / or Cu, the content of Mo being 6% to 16% and the content of Zn and / or Cu being 0.5% to 4.5%, based on the total weight of the catalyst, the mass ratio of Mo to S being 1.5 or more, and in the catalyst, Mo comprises +2 valence Mo, 0 valence Mo and +4 valence Mo, wherein, +2 valence Mo accounts for 50%-70% of total Mo in terms of atom, 0 valence Mo accounts for 10%-30% of total Mo in terms of atom, and +4 valence Mo accounts for 1%-25% of total Mo in terms of atom.

2. The catalyst according to claim 1, characterized in that, The mass ratio of Mo to S is 1.5-3.

0.

3. The catalyst of claim 2, wherein The mass ratio of Mo to S is 1.6-2.

4.

4. The catalyst of claim 1, wherein +2 valence Mo accounts for 50%-65% of total Mo in terms of atom, 0 valence Mo accounts for 15%-27% of total Mo in terms of atom, and +4 valence Mo accounts for 8%-25% of total Mo in terms of atom.

5. The catalyst of claim 1, wherein The sum of +4 valence Mo, +2 valence Mo and 0 valence Mo accounts for more than 90% of total Mo in terms of atom.

6. The catalyst of claim 5, wherein The sum of +4 valence Mo, +2 valence Mo and 0 valence Mo accounts for 90%-99% of total Mo in terms of atom.

7. The catalyst of claim 1, wherein The carrier is one or more of alumina, silica, amorphous silica-alumina.

8. The catalyst of claim 7, wherein The carrier contains one or more of phosphorus, silicon, boron, fluorine, magnesium, sodium modifying elements.

9. The catalyst of claim 8, wherein The modifying elements account for 0.2%-3.0% of the mass of the carrier.

10. The catalyst of claim 1, wherein The carrier accounts for 75%-92% of the mass of the catalyst, and Mo, S and Zn and / or Cu account for 8%-25% of the mass of the catalyst.

11. The catalyst of claim 1, wherein The support has the following properties: specific surface area of 230-400 m 2 / g, pore volume of 0.4-1.1 cm 3 / g.

12. The catalyst of claim 11, wherein, The support has the following properties: specific surface area of 250-360 m 2 / g, pore volume of 0.6-1.0 cm 3 / g.

13. A method for preparing the catalyst of any one of claims 1-12, comprising: (1) introducing molybdenum hexacarbonyl and an organic compound containing Zn and / or Cu into the carrier by impregnation to obtain catalyst precursor I; (2) contacting a dispersant with the catalyst precursor I in the presence of an inert gas to obtain catalyst precursor II; (3) using at least one of step (3-1) or step (3-2), wherein, step (3-1) comprises sulfidizing the catalyst precursor II; step (3-2) comprises impregnating catalyst precursor II with an impregnation solution containing polysulfide and then drying.

14. The method of claim 13, wherein, In step (1), the carrier is impregnated with an impregnation solution containing molybdenum hexacarbonyl and an organic compound containing Zn and / or Cu and then dried.

15. The method of claim 14, wherein, In step (1), the impregnation is isovolume impregnation or excess impregnation.

16. The method of claim 14, wherein, In step (1), the solvent in the impregnation solution is one or more of ethanol, benzene, toluene, xylene, ethylbenzene, tetralin.

17. The method of claim 16, wherein, In step (1), the solvent in the impregnation solution is at least one of toluene, xylene, ethylbenzene and tetralin, and optionally ethanol.

18. The method of claim 14, wherein, The organic zinc compound is selected from one or more of zinc propionate, zinc octoate, zinc lactate, zinc fumarate.

19. The method of claim 14, wherein, The organic copper compound is selected from at least one of copper propionate, copper naphthenate, copper citrate, copper acetylacetonate and copper lactate.

20. The method of claim 14, wherein, In step (1), the concentration of molybdenum hexacarbonyl in the impregnation solution is 0.2-2.5 mol / L, and the concentration of the organic zinc compound and / or the organic copper compound is 0.02-0.9 mol / L.

21. The method of claim 20, wherein, In step (1), the concentration of molybdenum hexacarbonyl in the impregnation solution is 0.3-2.0 mol / L, and the concentration of the organic zinc compound and / or the organic copper compound is 0.05-0.8 mol / L.

22. The method of claim 14, wherein, In step (1), the drying method is reduced pressure vacuum drying, wherein the drying temperature is 60-120°C, the vacuum degree during drying is 0.1-2.0 torr, and the drying time is 1-10 hours.

23. The method of claim 22, wherein, In step (1), the drying method is vacuum drying at a temperature of 80-100℃ under a vacuum of 0.2-1.0 torr for 2-8 hours.

24. The method of claim 13, wherein, In step (2), the dispersant is at least one selected from acetic acid, acetic anhydride, citric acid, dimethyl malonate, malonic acid and succinic acid. In step (2), the dispersant is used in an amount of 1-10 g per 1 g of the catalyst precursor I. In step (2), the contacting is performed under a pressure of 0-1.0 MPa at a temperature of 80-180℃ for 8-36 hours, wherein the pressure is gauge pressure. Optionally, after the contacting in step (2), the remaining dispersant is removed by evaporation drying.

25. The method of claim 24, wherein, In step (2), the dispersant is acetic acid and / or acetic anhydride. In step (2), the dispersant is used in an amount of 2-5 g per 1 g of the catalyst precursor I. In step (2), the contacting is performed under a pressure of 0.1-0.5 MPa at a temperature of 100-150℃ for 12-24 hours. Optionally, after the contacting in step (2), the remaining dispersant is removed by vacuum drying under reduced pressure.

26. The method of claim 24, wherein, The evaporation drying is performed at a temperature of 80-150℃ under a vacuum of 0.1-2 torr for 1-8 hours.

27. The method of claim 26, wherein, The evaporation drying is performed at a temperature of 100-120℃ under a vacuum of 0.2-1 torr for 2-6 hours.

28. The method of claim 13, wherein, In step (3-2), the solvent in the impregnation solution containing polysulfide is at least one selected from aromatic hydrocarbons, C5-C10 alkanes and C5-C10 cycloalkanes.

29. The method of claim 28, wherein, In step (3-2), the solvent in the impregnation solution containing polysulfide is one or more selected from cyclohexane, n-heptane, n-octane, tetrahydronaphthalene, decahydronaphthalene, toluene and xylene.

30. The method of claim 13, wherein, The mass concentration of polysulfide in the impregnation solution containing polysulfide is 2%-20%.

31. The method of claim 30, wherein, The mass concentration of polysulfide in the impregnation solution containing polysulfide is 3%-15%.

32. The method of claim 13, wherein, In step (3-2), the impregnation method is equal-volume impregnation.

33. The method of claim 32, wherein, After the impregnation in step (3-2), the material is dried by vacuum drying under reduced pressure at a temperature of 60-120℃ under a vacuum of 0.1-2.0 torr for 1-6 hours.

34. The method of claim 33, wherein, The drying is performed at a temperature of 80-100℃ under a vacuum of 0.2-1.0 torr for 2-4 hours.

35. The method of claim 13, wherein, The material obtained after the drying in step (3-2) is subjected to hydrogen treatment, wherein the hydrogen is introduced in one shot in an amount of 0.1-1 NL per 1 g of the dried material, and the hydrogen treatment is performed under a sealed condition.

36. The method of claim 35, wherein, The hydrogen is used in an amount of 0.2-0.8 NL per 1 g of the dried material.

37. The method of claim 35, wherein, The hydrogen treatment is performed at a temperature of 180-300℃ for 2.0-10.0 hours.

38. The method of claim 37, wherein, The hydrogen treatment temperature is 200-260℃, and the treatment time is 3.0-6.0 hours.

39. Use of the catalyst of any one of claims 1-12 in a hydrodenitrogenation reaction of a low-sulfur heavy feedstock having a mass content of sulfur of 8000 ppm or less.

40. The use according to claim 39, wherein The low-sulfur heavy feedstock is at least one of ebullated-bed hydroprocessing tail oil, coal tar, and Fischer-Tropsch synthesis oil.

41. The use according to claim 40, wherein The low-sulfur heavy feedstock is ebullated-bed hydroprocessing tail oil. The low-sulfur heavy feedstock is ebullated-bed hydroprocessing tail oil.

42. The use according to claim 40 or 41, characterized in that The low-sulfur heavy feedstock has a density of 0.95-1.05 g / cm 3 , a mass content of nitrogen of 500-5000 ppm, and a mass content of residual carbon of 8%-25%.

43. The use of claim 39, wherein, The hydrodenitrogenation reaction conditions are as follows: reaction temperature is 300-450℃, reaction pressure is 12-25 MPa, hydrogen / oil volume ratio is 500-2000:1, liquid hourly space velocity is 0.1-0.5h -1 .

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