A high water-resistant hydrocracking catalyst and its preparation method and application

Abstract

The present invention provides a highly water-resistant hydrocracking catalyst, comprising a porous carbon carrier on which a molecular sieve and a metal active component are loaded, wherein the metal active component is a Group VIB metal sulfide and a Group VIII metal sulfide. The hydrogenation catalyst is characterized using a TEM-EDS method, and the ratio of the molecular sieve directly interacting with the Group VIB metal sulfide to the total molecular sieve amount, calculated as silicon, is 60-100%. In the catalyst of the present invention, more molecular sieves directly act on the active metal, resulting in higher utilization rates of the molecular sieve and active metal, better exerting their active effects, and helping to reduce the amount of molecular sieve used, thereby reducing the cost of the catalyst. The catalyst of the present invention is suitable for oil hydrogenation, and is particularly suitable for the hydrocracking reaction process of biojet fuel and biodiesel.

Description

Technical Field

[0001] The present invention relates to the technical field of oil hydrogenation, and in particular to a highly water-resistant hydrocracking catalyst, and in particular to a preparation method and application thereof. Background Art

[0002] Biodiesel and biojet fuel are typically derived from various types of animal and plant oils, including microalgae oil, waste cooking oil, acidified oil, and vegetable oils such as jatropha oil. Animal and plant oils are high in olefin and oxygen content and are prone to coking at high temperatures. Furthermore, the hydrogenation process generates large amounts of water, placing high demands on the water resistance of hydrogenation catalysts.

[0003] CN201911371016.2 discloses a coal tar hydrogenation catalyst and its preparation method. The preparation method comprises the following steps: S1, preparing high-silicon pseudo-boehmite; S2, mixing the high-silicon pseudo-boehmite obtained in step S1 with an additive, forming, drying, and calcining the mixture to obtain a carrier, wherein the additive is one or more of a nickel salt, a lanthanum salt, a rhodium salt, and a silica sol; S3, introducing an active metal component onto the carrier obtained in step S2, and further drying and calcining the mixture to obtain a catalyst. This catalyst does not contain molecular sieves and is not suitable for biodiesel hydrocracking reactions.

[0004] CN201611011276.5 discloses a method for preparing a hydrocracking catalyst. The method comprises the following steps: (1) mixing, slurrying, and filtering at least one of amorphous silica-alumina or its precursor, macroporous alumina or its precursor, and a molecular sieve, wherein the dry weight of the amorphous silica-alumina or its precursor, macroporous alumina or its precursor is 15-30%, and the dry weight of the molecular sieve is 35-50%; (2) adding the small-pore alumina to a roller compactor, adding an appropriate amount of a peptizing agent, and after roller compaction, adding the material obtained in step (1), continuing roller compaction, extruding, drying, and calcining to obtain a hydrocracking catalyst carrier; and (3) introducing a hydrogenation-active metal component into the hydrocracking catalyst carrier obtained in step (2) by an impregnation method to obtain a hydrocracking catalyst. The large amount of water generated during the biodiesel hydrocracking process can significantly affect the acidic properties of the catalyst of the present invention, thereby affecting the cracking performance of the catalyst. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a highly water-resistant hydrocracking catalyst, which has high hydrocracking activity and high water resistance, and is suitable for reaction processes in which water is generated during the hydrogenation of biodiesel, bio-jet fuel, etc.

[0006] In order to achieve the above technical objectives, the technical solutions of the present invention are as follows:

[0007] The technical objective of the first aspect of the present invention is to provide a highly water-resistant hydrocracking catalyst, which uses porous carbon as a carrier on which a molecular sieve and a metal active component are loaded, wherein the metal active component is a Group VIB metal sulfide and a Group VIII metal sulfide; the hydrogenation catalyst is characterized by a TEM-EDS method, and the proportion of the molecular sieve directly interacting with the Group VIB metal sulfide to the total amount of the molecular sieve, calculated as silicon element, is 60-100%, preferably 65%-95%, more preferably 70%-90%, and most preferably 80%-90%.

[0008] The ratio of the molecular sieve directly reacting with the Group VIB metal sulfide to the total molecular sieve in the hydrocracking catalyst provided by the present invention is significantly higher than that in the catalyst provided in the prior art. The utilization rate of the molecular sieve and the active metal is higher, the active effect is better exerted, and it is beneficial to reduce the amount of molecular sieve used and reduce the cost of the catalyst.

[0009] In the present invention, the molecular sieve directly reacting with the Group VIB metal sulfide means that the molecular sieve is supported on the surface of the wafer of the Group VIB metal sulfide.

[0010] In the present invention, the ratio of the amount of molecular sieve that directly interacts with the Group VIB metal sulfide to the total amount of molecular sieve is expressed as "total molecular sieve content" (calculated as silicon), while the amount of molecular sieve that directly interacts with the Group VIB metal sulfide refers to the amount of molecular sieve within 2 nm of the outermost layer of the Group VIB metal sulfide crystal (calculated as silicon). The ratio of the amount of molecular sieve that directly interacts with the Group VIB metal sulfide to the total amount of molecular sieve was determined using TEM-EDS (transmission electron microscopy-energy dispersive X-ray spectroscopy) using a JEOL JEM2200FS transmission electron microscope (Japan) equipped with a scanning transmission electron microscope (STEM) and an EDAX X-ray spectrometer (USA). The accelerating voltage was 200 kV, and in STEM mode, the condenser aperture was set to 2, with a spot size of 0.5 nm. The determination process is as follows: the catalyst particles are ground and sampled using a suspension method. 0.1 g of the catalyst sample is placed in a 2 mL container and ultrasonically dispersed with anhydrous ethanol. The supernatant is collected and two to three drops are taken with a dropper and placed on a 3 mm diameter sample mesh. The sample is dried to obtain a test sample. The test sample is then observed and analyzed using TEM. The Si content at a distance less than 2 nm from the edge endpoint of the active phase (Group VIB metal sulfide crystal) observed by TEM is statistically analyzed in conjunction with EDS. The corresponding Si peak area is used to determine the proportion of the molecular sieve directly interacting with the Group VIB metal sulfide to the total molecular sieve. The proportion of the molecular sieve directly interacting with the Group VIB metal sulfide to the total molecular sieve is calculated by averaging the data obtained from 40 TEM images combined with EDS analysis.

[0011] Furthermore, based on the total weight of the catalyst, the molecular sieve accounts for 1-15 wt%, preferably 1.5-10 wt%, and more preferably 2-8 wt%. The present invention improves the utilization of the molecular sieve by increasing the proportion of the molecular sieve that directly interacts with the Group VIB metal sulfide relative to the total weight of the molecular sieve. Even at a relatively low molecular sieve content, the catalyst can still exhibit good hydrocracking performance, thereby reducing the cost of the hydrocracking catalyst.

[0012] Furthermore, the Group VIB metal sulfide, calculated as sulfide, accounts for 10-30%, preferably 15-28%, and the Group VIII metal sulfide, calculated as sulfide, accounts for 2-10%, preferably 4-8%. The hydrogenation catalyst provided by the present invention is a sulfurized hydrogenation catalyst, in which the majority of the active components exist in the form of sulfides. The catalyst provided by the present invention may contain small amounts of Group VIB metal oxides and Group VIII metal oxides.

[0013] The present invention has no particular limitation on the method for determining the content of molecular sieve in the catalyst. The content can be determined by combining the amount of silicon oxide with the crystal form of the molecular sieve determined by XRD, or calculated by feeding during the catalyst preparation process.

[0014] Furthermore, the molecular sieve is at least one selected from the group consisting of Y-type molecular sieve, ZSM-5 molecular sieve, β-type molecular sieve, and MCM-41 molecular sieve. The molecular sieve can be commercially available or synthesized by existing methods, and the present invention is not particularly limited thereto.

[0015] Furthermore, the Group VIB metal sulfide is MoS2 or / and WS2, and the Group VIII metal sulfide is CoS or / and NiS.

[0016] In the present invention, the contents of Group VIB metal sulfides and Group VIII metal sulfides can be jointly characterized by inductively coupled plasma (ICP) and XPS spectroscopy. Specifically, the total contents of Group VIB metals and Group VIII metals in the catalyst are first characterized by ICP, and then the contents of metal elements of different valence states in the catalyst are quantitatively characterized by XPS spectrometer. The measurement conditions of the XPS spectrum include: the vacuum degree of the analysis chamber is ≤5×10 -10 mbar; vacuum degree of preparation chamber ≤1×10 -7 mbar; dual anode sensitivity 4.5×10 6 , energy resolution 1.0 eV; monochromator sensitivity 1.4×10 5 The energy resolution was 0.5 eV. XPSPEAK Version 4.0 was used to fit and separate the energy spectra of Mo3d, W4f, Co2p, and Ni2p, and the contents of metal elements with different valence states in the catalyst were calculated based on the peak areas.

[0017] Furthermore, the porous carbon is a porous carbon material with a specific surface area of ​​500-2000m 2 / g, pore volume of 1.0-3.0cm 3 / g, average pore size 1-8nm.

[0018] The technical purpose of the second aspect of the present invention is to provide a method for preparing a highly water-resistant hydrocracking catalyst, comprising the following steps:

[0019] (1) introducing a Group VIB metal salt and a Group VIII metal salt into a porous carbon support by an impregnation method, followed by sulfidation to obtain a catalyst precursor;

[0020] (2) Introducing molecular sieves into the catalyst precursor, followed by drying and calcining.

[0021] According to the method provided by the present invention, the selection range of the carrier and the VIB Group metal and the VIII Group metal species can be the same as the selection range of the carrier and the VIB Group metal and the VIII Group metal species in the hydrogenation catalyst described in the first aspect above, and the present invention will not be repeated here.

[0022] Furthermore, the impregnation in step (1) is an equal volume impregnation or a supersaturated impregnation. The Group VIB metal salt and the Group VIII metal salt can be simultaneously introduced into the porous carbon support by co-impregnation, or can be separately introduced into the porous carbon support by step-by-step impregnation. There is no particular limitation on the order of introduction. Preferably, the Group VIB metal salt and the Group VIII metal salt are simultaneously introduced into the porous carbon support by co-impregnation.

[0023] Furthermore, after the impregnation in step (1) is completed, a drying process is further included, and the drying is preferably carried out under an inert atmosphere. The drying conditions include: a temperature of 20-90°C and a time of 4-16 hours. The inert atmosphere refers to an atmosphere that does not participate in the reaction and can be provided by an inert gas, including but not limited to at least one of nitrogen, helium, argon and neon.

[0024] Furthermore, in the impregnation process of step (1), an organic auxiliary agent is preferably added to the impregnation liquid to facilitate the dispersion of the active component. The organic auxiliary agent is preferably a compound containing hydroxyl and / or carboxyl groups and having 2 to 10 carbon atoms. More specifically, the organic auxiliary agent is selected from at least one of ethylene glycol, glycerol, butanediol, pentanediol, acetic acid, citric acid, malonic acid, succinic acid, and glutaric acid.

[0025] The present invention has a wide range of selection for the types of Group VIB metal salts and Group VIII metal salts, based on the ability to subsequently convert into their respective metal sulfides. Preferably, the Group VIB metal salt is a phosphate and / or ammonium salt of a Group VIB metal, and the Group VIII metal salt is at least one of a nitrate, acetate, and sulfate of a Group VIII metal.

[0026] The present invention does not particularly limit the sulfurization in step (1). It can be carried out using conventional methods in the art, as long as the active metal in the oxidized hydrogenation catalyst is converted to a sulfurized state. A known sulfurization method can be used. Preferably, the sulfurization is dry sulfurization or wet sulfurization. The dry sulfurization and wet sulfurization in the present invention have the conventional meanings in the art.

[0027] Preferably, the vulcanization conditions include: vulcanization pressure of 3.2-6.4 MPa, vulcanization temperature of 250-400°C, vulcanization time of 4-12 hours, and hydrogen flow rate of 2-25 mL·min -1 ·g -1 .

[0028] According to a preferred embodiment of the present invention, the dry vulcanizing agent used in the dry vulcanization is hydrogen sulfide. Specifically, the sulfide gas used in the dry vulcanization comprises hydrogen sulfide and hydrogen. Preferably, the volume content of hydrogen sulfide in the sulfide gas is 1-10%.

[0029] According to a preferred embodiment of the present invention, the wet vulcanizing agent used in the wet vulcanization is at least one of carbon disulfide, dimethyl disulfide, methyl sulfide and n-butyl sulfide. Specifically, the vulcanizing liquid used in the wet vulcanization comprises the wet vulcanizing agent and an organic solvent. Preferably, the organic solvent is selected from at least one of cyclohexane, n-heptane, aviation kerosene and diesel. The mass fraction of the wet vulcanizing agent in the vulcanizing liquid is selected in a wide range, preferably 2%-7%, more preferably 4%-6%. The flow rate of the vulcanizing liquid is preferably 0.5-5 mL·h -1 ·g -1 , preferably 1-4 mL·h -1 ·g -1 .

[0030] According to a preferred embodiment of the present invention, the amounts of the Group VIB metal salt and the Group VIII metal salt are such that, in the resulting catalyst, the content of the Group VIB metal sulfide, calculated as sulfide, is 10-30 wt %, preferably 15-28 wt %, and the content of the Group VIII metal sulfide, calculated as sulfide, is 2-10 wt %, preferably 4-8 wt %, based on the total weight of the catalyst. Those skilled in the art can appropriately select the amounts of the Group VIB and Group VIII metal salts and the sulfurization conditions based on this requirement.

[0031] According to the present invention, preferably, the catalyst precursor and molecular sieve are used in amounts such that the content of molecular sieve in the prepared catalyst is 1-15 wt %, preferably 1.5-10 wt %, and more preferably 2-8 wt %, based on the total weight of the catalyst. According to the method provided by the present invention, the range of selection of the molecular sieve type in step (2) can be the same as the range of selection of the molecular sieve type in the hydrogenation catalyst described in the first aspect above, and the present invention will not be repeated here.

[0032] Furthermore, the method of introducing the molecular sieve into the catalyst precursor in step (2) is not particularly limited, and the catalyst precursor and the molecular sieve may be directly mixed, or the catalyst precursor and the molecular sieve precursor may be mixed and then subjected to hydrothermal treatment.

[0033] Preferably, the method of introducing the molecular sieve into the catalyst precursor in step (2) is carried out in at least one of the following ways:

[0034] (a) subjecting the catalyst precursor and the molecular sieve precursor to hydrothermal treatment, and performing the drying and calcining described in step (3) under an inert atmosphere;

[0035] (b) In the presence of a solvent, the catalyst precursor is mixed with the ball-milled molecular sieve, and then the mixture is dried and calcined as described in step (3).

[0036] According to the present invention, it is understood that the molecular sieve precursor can be a gel produced by hydrothermal treatment to produce the aforementioned molecular sieves. Preferably, in method (a), the molecular sieve precursor comprises a gel formed by mixing a silicon source and / or aluminum source, a precipitant, a template, and water. Preparation methods are well known to those skilled in the art, and the molecular sieve can be formed using a precipitation method or a sol-gel method.

[0037] The types of the silicon source and / or aluminum source, precipitant, and template are well known to those skilled in the art. The silicon source is preferably selected from at least one of sodium silicate, tetraethyl orthosilicate, silica sol, and chromatography silica gel. The aluminum source is preferably selected from at least one of sodium metaaluminate, aluminum hydroxide, and pseudo-boehmite. The precipitant is preferably selected from at least one of sodium hydroxide, aqueous ammonia, and potassium hydroxide. The template is preferably selected from at least one of hexadecyltrimethylammonium bromide, ethylenediamine, n-butylamine, tetrapropylammonium bromide, ethanol, tetraethylammonium hydroxide, tetraethylammonium bromide, triethylamine, di-n-propylamine, diisopropylamine, and methylcellulose.

[0038] Furthermore, when the molecular sieve is a silica-alumina molecular sieve, preferably, the molar composition of the gel is n(SiO2):n(Al2O3):n(Na2O):n(template):n(H2O)=(5-30):1:(1-10):(1-10):(100-300).

[0039] Furthermore, when the molecular sieve is an all-silicon molecular sieve, preferably, the molar composition of the gel is n(SiO2):n(Na2O):n(template):n(H2O)=100:(10-30):(10-30):(1500-3000).

[0040] The present invention has a wide range of conditions for the hydrothermal treatment, based on the ability to obtain the molecular sieve. Preferably, the hydrothermal treatment conditions include: temperature of 90-200°C, pressure of 0.1-2MPa, pH of 7.5-9, and time of 5-48 hours.

[0041] Furthermore, in method (b), the particle size of the molecular sieve after ball milling is 0.1-10 nm, more preferably 0.1-5 nm. This preferred embodiment is more conducive to the full utilization of the molecular sieve. The present invention does not specifically limit the parameters and equipment of the ball milling.

[0042] According to a preferred embodiment of the present invention, the drying conditions in step (2) include: a temperature of 20-90° C. and a drying time of 4-16 hours.

[0043] According to a preferred embodiment of the present invention, the calcination conditions in step (2) include: a temperature of 300-500° C. and a time of 2-5 hours.

[0044] The drying and calcining in step (2) can be carried out under an inert atmosphere. The specific selection of the inert atmosphere can be as described above.

[0045] The technical purpose of the third aspect of the present invention is to provide the use of the hydrocracking catalyst described in the first aspect or the hydrocracking catalyst prepared by the method described in the second aspect in the hydrogenation of oil products.

[0046] Furthermore, the above hydrocracking catalyst is particularly suitable for the hydrocracking reaction process of bio-jet fuel and bio-diesel.

[0047] Furthermore, the process conditions of the hydrocracking reaction are: pressure 1.0~12.0MPa, preferably 6.0~10.0MPa, wherein the hydrogen partial pressure accounts for 50%~90% of the total pressure; volume space velocity 0.1~10.0h -1 , preferably 0.5~3.0h -1 The reaction temperature is 200-400°C, preferably 330-380°C; the hydrogen-to-oil volume ratio is 10:1-1000:1, preferably 100:1-800:1.

[0048] Compared with the prior art, the catalyst of the present invention has the following advantages:

[0049] (1) The catalyst of the present invention includes a porous carbon support, a molecular sieve and an active component, and more molecular sieves act directly on the active metal, giving full play to the ability of the molecular sieve to provide H protons, improving the hydrogenation activity of the catalyst, and having a higher utilization rate of the molecular sieve and the active metal, so as to better exert the active effect, and is conducive to reducing the amount of molecular sieve used and reducing the cost of the catalyst.

[0050] (2) The carrier of the present invention adopts porous carbon, which can effectively improve the water resistance of the catalyst and prevent the catalyst structure from collapsing and breaking in a water-containing environment, causing a bed pressure drop. On the other hand, the interaction between the carbon carrier and the active metal is weak, which is conducive to generating more active sites, thereby improving the activity of the catalyst. Thirdly, because the carbon layer is non-polar, the molecular sieve will react more with the metal, increasing the ratio of direct interaction between the molecular sieve and the active metal.

[0051] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0052] The following non-limiting examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0053] In the hydrogenation catalysts of the following Examples and Comparative Examples, the proportion of the molecular sieve directly interacting with the Group VIB metal sulfide relative to the total molecular sieve content was characterized using TEM-EDS (transmission electron microscopy-energy dispersive X-ray spectroscopy), as described in the Summary of the Invention. The contents of the Group VIB metal sulfide and Group VIII metal sulfide can be determined by combining inductively coupled plasma (ICP) and XPS spectroscopy, as described in the Summary of the Invention. The molecular sieve content was calculated by the weight difference between the catalyst precursor and the final catalyst.

[0054] Example 1

[0055] (1) A solution of nickel nitrate and ammonium heptamolybdate was impregnated into the porous carbon support by pore saturation impregnation, and then dried at 80 °C for 3 h in a nitrogen atmosphere. The porous carbon support was then sulfided using hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min -1 ·g -1 The sulfurization temperature is 300 ° C, the sulfurization pressure is 3.2 MPa, and the sulfurization time is 4 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0056] (2) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(ethylenediamine):n(H2O)=13:2:6:3:170, and stirred until a uniform sol was formed, i.e., a precursor of Y molecular sieve. The sol was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 150°C, 1.0 MPa, and pH=8.0 for 10 h; then filtered, washed three times with deionized water, dried at 80°C for 3 h in a nitrogen atmosphere, and calcined at 450°C for 3 h to obtain catalyst C-1.

[0057] The weight percentages of the components in catalyst C-1 are: MoS2 is 18%, NiS is 4.6%, Y molecular sieve is 2.5%, and the rest is the carrier.

[0058] Example 2

[0059] (1) A solution of nickel nitrate and ammonium heptamolybdate was impregnated into the porous carbon support by pore saturation impregnation, and then dried at 90 °C for 3 h in a nitrogen atmosphere. The porous carbon support was then sulfided using hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min -1 ·g -1 The sulfurization temperature is 310 ° C, the sulfurization pressure is 3.6 MPa, the sulfurization time is 6 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0060] (2) Sodium hydroxide, silica sol, sodium metaaluminate and n-butylamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(n-butylamine):n(H2O)=22:1:7:6:200, and stirred to form a uniform sol, i.e., a precursor of ZSM-5 molecular sieve. The sol was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 130°C, 1.0 MPa, and pH=8.5 for 24 h; then filtered, washed three times with deionized water, dried at 80°C for 3 h in a nitrogen atmosphere, and calcined at 500°C for 3 h to obtain catalyst C-2.

[0061] The weight percentages of the components in catalyst C-2 are: MoS2 is 22%, NiS is 4.2%, ZSM-5 molecular sieve is 3.5%, and the rest is the carrier.

[0062] Example 3

[0063] (1) A solution of nickel nitrate and ammonium heptamolybdate was impregnated into the porous carbon support by pore saturation impregnation, and then dried at 90 °C for 3 h in a nitrogen atmosphere. The porous carbon support was then sulfided using hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min -1 ·g -1The sulfurization temperature is 300 ° C, the sulfurization pressure is 4.0 MPa, the sulfurization time is 6 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0064] (2) Sodium aluminate and sodium hydroxide were dissolved in deionized water, and then tetraethylammonium bromide was added. The mixture was stirred vigorously, and silica sol was slowly added dropwise. The mixture was aged for 3 h. The molar ratio of each component was n(SiO2):n(Al2O3):n(Na2O):n(tetraethylammonium bromide):n(H2O)=22:1:6:5:230 to form a precursor of a β-type molecular sieve. The precursor was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 130°C, 1.0 MPa, and pH=8.5 for 15 h. The mixture was then filtered, washed three times with deionized water, dried at 90°C for 3 h in a nitrogen atmosphere, and calcined at 500°C for 3 h to obtain catalyst C-3.

[0065] The weight percentages of the components in catalyst C-3 are: MoS2 is 22%, NiS is 3.6%, β-type molecular sieve is 5.0%, and the rest is the carrier.

[0066] Example 4

[0067] (1) A solution of nickel nitrate and ammonium heptamolybdate was impregnated into the porous carbon support by pore saturation impregnation, and then dried at 80 °C for 4 h in a nitrogen atmosphere. The porous carbon support was then sulfided using hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min -1 ·g -1 The sulfurization temperature is 320 ° C, the sulfurization pressure is 3.5 MPa, the sulfurization time is 6 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0068] (2) Hexadecyltrimethylammonium bromide and sodium hydroxide were mixed and then added to deionized water. After stirring, ethyl orthosilicate was added dropwise to the mixed solution. After stirring for 30 minutes, the molar ratio of each component was n(SiO2):n(Na2O):n(hexadecyltrimethylammonium bromide):n(H2O)=10:2:2:200, forming an MCM-41 molecular sieve precursor, which was then mixed with the catalyst precursor prepared in step (1) and then hydrothermally treated at 130°C, 1.0 MPa, and pH=8.5 for 18 hours; then filtered, washed three times with deionized water, dried at 80°C for 3 hours in a nitrogen atmosphere, and calcined at 450°C for 3 hours to obtain catalyst C-4.

[0069] The weight percentages of the components in catalyst C-4 are: MoS2 is 21%, NiS is 4.3%, MCM-41 molecular sieve is 3.8%, and the rest is the carrier.

[0070] Example 5

[0071] (1) The porous carbon support was impregnated with a solution of cobalt nitrate and ammonium heptamolybdate by pore saturation impregnation, and then dried at 90 °C for 3 h in a nitrogen atmosphere. The support was then sulfided with hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min -1 ·g -1 The sulfurization temperature is 320 ° C, the sulfurization pressure is 4.2 MPa, the sulfurization time is 6 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0072] (2) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(ethylenediamine):n(H2O)=123:1:6:3:190, and stirred to form a uniform sol, i.e., a precursor of Y molecular sieve. The sol was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 120°C, 1.0 MPa, and pH=9.0 for 20 h; then filtered, washed three times with deionized water, dried at 80°C for 3 h in a nitrogen atmosphere, and calcined at 500°C for 3 h to obtain catalyst C-5.

[0073] The weight percentages of the components in catalyst C-5 are: MoS2 is 21%, CoS is 5.1%, Y molecular sieve is 3.5%, and the rest is the carrier.

[0074] Example 6

[0075] (1) The porous carbon support was impregnated with a solution of nickel nitrate and ammonium metatungstate by pore saturation impregnation, and then dried at 80 °C for 3 h in a nitrogen atmosphere. The support was then sulfided with hydrogen containing 1.5 vol% H2S at a temperature of 320 °C and a hydrogen flow rate of 10 mL min. -1 ·g -1 The sulfurization pressure was 3.0 MPa, the sulfurization time was 4 h, and then the temperature was cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0076] (2) Sodium hydroxide, silica sol, sodium metaaluminate and n-butylamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(n-butylamine):n(H2O)=21:1:7:6:180, and stirred to form a uniform sol, i.e., a precursor of ZSM-5 molecular sieve. The sol was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 140°C, 1.0 MPa, and pH=8.5 for 15 h; then filtered, washed three times with deionized water, dried at 90°C for 3 h in a nitrogen atmosphere, and calcined at 500°C for 3 h to obtain catalyst C-6.

[0077] The weight percentages of the components in catalyst C-6 are: WS2 is 22%, NiS is 4.8%, ZSM-5 molecular sieve is 4.3%, and the rest is the carrier.

[0078] Example 7

[0079] (1) The porous carbon support was impregnated with a solution of cobalt nitrate and ammonium metatungstate by pore saturation impregnation, and then dried at 90 °C for 3 h in a nitrogen atmosphere. The support was then sulfided with hydrogen containing 1.5 vol% H2S at a flow rate of 10 mL min. -1 ·g -1 The sulfurization temperature is 320 ° C, the sulfurization pressure is 4.0 MPa, and the sulfurization time is 6 h, and then it is cooled to room temperature in a N2 atmosphere to obtain a catalyst precursor.

[0080] (2) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(ethylenediamine):n(H2O)=13:1:6:3:200, and stirred until a uniform sol was formed, i.e., a precursor of Y molecular sieve. The sol was then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 130°C, 1.0 MPa, and pH=8.5 for 15 h; then filtered, washed three times with deionized water, dried at 90°C for 3 h in a nitrogen atmosphere, and calcined at 450°C for 3 h to obtain catalyst C-7.

[0081] The weight percentages of the components in catalyst C-7 are: WS2 is 22%, CoS is 4.8%, Y molecular sieve is 3.5%, and the rest is the carrier.

[0082] Example 8

[0083] The method of Example 1 is followed, except that in step (2), the catalyst precursor prepared in step (1) is directly mixed with the ball-milled Y-type molecular sieve (particle size of 0.2-2.0 nm), and then the drying and calcination are performed. The preparation of the Y-type molecular sieve comprises: adding sodium hydroxide, silica sol, sodium metaaluminate and ethylenediamine to deionized water, wherein the molar ratio of each component is n(SiO2):n(Al2O3):n(Na2O):n(ethylenediamine):n(H2O)=12:1:6:3:180, stirring until a uniform sol is formed, and then hydrothermally treating the mixture at 150°C, 1.0 MPa, and pH=8.0 for 10 hours; then filtering, washing with deionized water three times, and then drying at 90°C for 3 hours in a nitrogen atmosphere and calcining at 450°C for 3 hours to obtain catalyst C-8.

[0084] Example 9

[0085] Catalyst C-9 was obtained by following the method of Example 1, except that the content of molecular sieve was 16%, the contents of MoS2 and NiS remained unchanged, and the content of alumina carrier was reduced accordingly.

[0086] Comparative Example 1

[0087] (1) Y-type molecular sieve was uniformly mixed with porous carbon, nitric acid, starch and deionized water, wherein the mass ratio of Y-type molecular sieve: porous carbon: nitric acid: starch: deionized water was 9:91:4:3:60, and then kneaded and extruded into strips, and then dried at 80°C in a nitrogen atmosphere for 10 hours and calcined at 600°C for 3 hours to obtain a carrier, in which the content of Y-type molecular sieve was 9%.

[0088] (2) A mixed solution of phosphomolybdic acid and nickel nitrate was impregnated into the carrier prepared in step (1), and then dried at 90°C for 3 hours in a nitrogen atmosphere, calcined at 450°C for 3 hours, and then subjected to a sulfurization treatment at a sulfurization temperature of 320°C, a sulfurization pressure of 3.0 MPa, and a sulfurization time of 4 hours. The catalyst was then cooled to room temperature in a N2 atmosphere to obtain catalyst DC-1.

[0089] The weight percentages of the components in catalyst DC-1 are: MoS2 is 20%, NiS is 4.8%, Y molecular sieve content is 5.1%, and the rest is porous carbon.

[0090] Comparative Example 2

[0091] (1) A solution of cobalt nitrate and ammonium metatungstate was impregnated into a porous carbon support, which was then dried at 90 °C for 3 h in a nitrogen atmosphere and calcined at 400 °C for 3 h to obtain a catalyst precursor.

[0092] (2) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water in a molar ratio of n(SiO2):n(Al2O3):n(Na2O):n(ethylenediamine):n(H2O)=12:1:6:3:180, and stirred to form a uniform sol, i.e., a precursor of Y molecular sieve, and then mixed with the catalyst precursor prepared in step (1), and then hydrothermally treated at 130°C, 1.0 MPa, and pH=8.5 for 15 h; then filtered, washed three times with deionized water, dried at 90°C in a nitrogen atmosphere for 3 h, and then sulfurized with hydrogen containing 1.5% by volume of H2S at a sulfurization temperature of 320°C, a sulfurization pressure of 3.0 MPa, and a sulfurization time of 4 h, and then cooled to room temperature in a N2 atmosphere to obtain catalyst DC-2.

[0093] The weight percentages of the components in the catalyst DC-2 are: WS2 is 22%, CoS is 4.2%, Y molecular sieve is 5.0%, and the rest is the carrier.

[0094] In the above examples and comparative examples, the ratio of the amount of molecular sieve that directly reacts with the Group VIB metal sulfide to the total amount of molecular sieve, calculated as silicon element, is listed in Table 1.

[0095] Table 1

[0096]

[0097] Application Example 1

[0098] This application example illustrates the hydrocracking performance of the catalyst provided by the present invention for biodiesel.

[0099] The evaluation feedstock used was a biodiesel feedstock with the following main properties: a distillation range of 200-380°C and an oxygen content of 2.1%. The hydrogenation performance of the catalysts provided in the Examples and Comparative Examples was evaluated using a 200mL fixed-bed hydrogenation apparatus. The evaluation reaction conditions were: an operating pressure of 8.0 MPa, a reaction temperature of 380°C, a hydrogen / oil volume ratio of 500:1, and a volume space velocity of 2.0 h / min. -1 The evaluation results of the reaction for 300 h are shown in Table 2.

[0100] Table 2

[0101]

Claims

1. A highly water-resistant hydrocracking catalyst, characterized in that: A porous carbon carrier is used to support a molecular sieve and a metal active component, wherein the metal active component is a Group VIB metal sulfide and a Group VIII metal sulfide. The hydrocracking catalyst is characterized by a TEM-EDS method. The ratio of the molecular sieve directly interacting with the Group VIB metal sulfide to the total molecular sieve is 60-100% based on silicon element. Based on the total weight of the catalyst, the molecular sieve accounts for 1-15wt%, the Group VIB metal sulfide accounts for 10-30% based on sulfide, and the Group VIII metal sulfide accounts for 2-10% based on sulfide. The highly water-resistant hydrocracking catalyst is prepared by the following method: (1) introducing a Group VIB metal salt and a Group VIII metal salt into a porous carbon support by an impregnation method, and sulfiding the mixture to obtain a catalyst precursor; during the impregnation process, an organic additive is added to the impregnation solution, wherein the organic additive is a compound having 2 to 10 carbon atoms and containing hydroxyl and / or carboxyl groups; (2) Introducing molecular sieves into the catalyst precursor, followed by drying and calcining.

2. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The amount of molecular sieve that directly reacts with Group VIB metal sulfide accounts for 65%-95% of the total amount of molecular sieve.

3. The highly water-resistant hydrocracking catalyst according to claim 2, characterized in that The amount of molecular sieve that directly reacts with Group VIB metal sulfide accounts for 70%-90% of the total amount of molecular sieve.

4. The highly water-resistant hydrocracking catalyst according to claim 3, characterized in that The amount of molecular sieve that directly reacts with Group VIB metal sulfide accounts for 80%-90% of the total molecular sieve amount.

5. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that Based on the total weight of the catalyst, the molecular sieve accounts for 1.5-10 wt%.

6. The highly water-resistant hydrocracking catalyst according to claim 5, characterized in that Based on the total weight of the catalyst, the molecular sieve accounts for 2-8 wt%.

7. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The molecular sieve is at least one selected from Y-type molecular sieve, ZSM-5 molecular sieve, β-type molecular sieve and MCM-41 molecular sieve.

8. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The porous carbon is a porous carbon material with a specific surface area of ​​500-2000m 2 / g, pore volume of 1.0-3.0cm 3 / g, average pore size 1-8nm.

9. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The impregnation in step (1) is equal volume impregnation or supersaturated impregnation.

10. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that After the impregnation in step (1) is completed, a drying process is also included. The drying conditions include: a temperature of 20-90° C. and a time of 4-16 hours.

11. The highly water-resistant hydrocracking catalyst according to claim 10, characterized in that The drying in step (1) is carried out under an inert atmosphere.

12. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The organic auxiliary agent is selected from at least one of ethylene glycol, glycerol, butylene glycol, pentanediol, acetic acid, citric acid, malonic acid, succinic acid and glutaric acid.

13. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The Group VIB metal salt is a phosphate and / or ammonium salt of a Group VIB metal, and the Group VIII metal salt is at least one of a nitrate, an acetate and a sulfate of a Group VIII metal.

14. The highly water-resistant hydrocracking catalyst according to claim 1, characterized in that The method of introducing the molecular sieve into the catalyst precursor in step (2) is carried out in at least one of the following ways: (a) subjecting the catalyst precursor and the molecular sieve precursor to hydrothermal treatment, and performing the drying and calcining steps (2) under an inert atmosphere; (b) In the presence of a solvent, the catalyst precursor is mixed with the ball-milled molecular sieve, and then the mixture is dried and calcined as described in step (2).

15. The highly water-resistant hydrocracking catalyst according to claim 14, characterized in that In method (a), the molecular sieve precursor includes a silicon source or a silicon source and an aluminum source, which are mixed with a precipitant, a template and water to form a gel.

16. The highly water-resistant hydrocracking catalyst according to claim 15, characterized in that The silicon source is selected from at least one of sodium silicate, ethyl orthosilicate, silica sol and chromatographic silica gel; the aluminum source is selected from at least one of sodium aluminate, aluminum hydroxide and pseudo-boehmite; the precipitant is selected from at least one of sodium hydroxide, ammonia water and potassium hydroxide; and the template is selected from at least one of hexadecyltrimethylammonium bromide, ethylenediamine, n-butylamine, tetrapropylammonium bromide, ethanol, tetraethylammonium hydroxide, tetraethylammonium bromide, triethylamine, di-n-propylamine, diisopropylamine and methylcellulose.

17. The highly water-resistant hydrocracking catalyst according to claim 15, characterized in that When the molecular sieve is a silica-alumina molecular sieve, the molar composition of the gel is SiO2:Al2O3:Na2O:template:H2O=5-30:1:1-10:1-10:100-300.

18. The highly water-resistant hydrocracking catalyst according to claim 15, wherein When the molecular sieve is an all-silicon molecular sieve, the molar composition of the gel is SiO2: Na2O: template: H2O=100:10-30:10-30:1500-3000.

19. The highly water-resistant hydrocracking catalyst according to claim 14, characterized in that In method (a), the conditions of the hydrothermal treatment include: temperature of 90-200° C., pressure of 0.1-2 MPa, pH of 7.5-9, and time of 5-48 hours.

20. The highly water-resistant hydrocracking catalyst according to claim 14, characterized in that In method (b), the particle size of the molecular sieve after ball milling is 0.1-10 nm.

21. The highly water-resistant hydrocracking catalyst according to claim 14, characterized in that The drying conditions in step (2) include: a temperature of 20-90° C. and a drying time of 4-16 hours.

22. The highly water-resistant hydrocracking catalyst according to claim 14, characterized in that The calcination conditions in step (2) include: a temperature of 300-500° C. and a time of 2-5 hours.

23. Use of the highly water-resistant hydrocracking catalyst according to claim 1 in an oil hydrotreating process.

24. The use according to claim 23, characterized in that The hydrocracking catalyst is used in the hydrocracking reaction process of bio-jet fuel and bio-diesel.

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