Hydrodenitrogenation and carbon residue removal catalyst as well as preparation method and application thereof

Abstract

The invention provides a hydrodenitrogenation and carbon residue removal catalyst as well as a preparation method and application thereof, and the preparation method comprises the following steps: preparing unit cell distortion pseudo-boehmite P1; mixing the P1 with pseudo-boehmite P2, and dipping with a boric acid solution to obtain boron modified pseudo-boehmite F1; mixing the P1 and pseudo-boehmite P3, and impregnating the mixture with a phosphorus-containing solution to obtain phosphorus-modified pseudo-boehmite F2; carrying out ball rolling molding on the F1 to obtain an alumina carrier precursor; mixing the alumina carrier precursor with F2, rolling and molding, and then drying and roasting to obtain the alumina carrier; impregnating the alumina carrier with the impregnation liquid to obtain a catalyst intermediate; immersing the catalyst intermediate into a urea solution A for hydrothermal treatment, and washing, drying and roasting the material subjected to hydrothermal treatment to prepare the hydrodenitrogenation and carbon residue removal catalyst, the catalyst prepared by the method has the advantages of large average pore size of the shell layer, high B acid content of the core layer, and appropriate action between the active metal and the carrier in the catalyst, and is suitable for the field of catalyst preparation.

Description

Technical Field

[0001] The present application relates to the field of catalyst preparation, and specifically to a hydrodenitrogenation and carbon residue removal catalyst, and a preparation method and application thereof. Background Art

[0002] With the increasing heaviness and degradation of crude oil worldwide and the continued growth in demand for lighter oil products, residue hydrotreating has become an effective means of upgrading and lightening heavy oil. Fixed-bed residue hydrotreating technology, with its mature process, simple operation, and high product quality, is the most widely used heavy oil hydrotreating technology.

[0003] In existing fixed-bed residue hydroprocessing processes, the pore size of the front-end hydrodemetallization catalyst is relatively large, allowing the colloids and asphaltenes to undergo hydrodepolymerization and side chain cleavage reactions. However, the pore size of the rear-end hydrodenitrogenation and carbon removal catalyst is relatively small. After the front-end depolymerization and side chain cleavage, the core structure of the colloids and asphaltenes still has a relatively large volume. These macromolecules cannot enter the catalyst pores, resulting in dehydrogenation polycondensation reactions, producing macromolecules with a higher degree of condensation. These highly condensed macromolecules will deposit on the catalyst in the form of carbon deposits, causing catalyst deactivation. The greater the amount of carbon deposits, the more severe the catalyst deactivation. Severe carbon deposits can also lead to catalyst compaction, resulting in increased reactor pressure drop or hot spots in the catalyst bed, shortening the operating cycle of the fixed-bed residue hydroprocessing unit.

[0004] Patent application number CN201510724539.6 discloses a hydrodenitrogenation catalyst, its preparation method, and application. The catalyst contains an active metal component and a modified hydrogenation catalyst support. The preparation method of the modified hydrogenation catalyst support comprises: repeatedly impregnating and drying the hydrothermally treated support, and calcining the dried product obtained at the last time, wherein the impregnation solution used in each impregnation process contains the same or different acidic additive compounds, the number of repetitions n≥2, and when n≥3, in the process from the second impregnation to the n-1th impregnation, the drying temperature after each impregnation is 20-150°C higher than the drying temperature after the adjacent previous impregnation, and the drying time after each impregnation is 1-10 hours longer than the drying time after the adjacent previous impregnation. This method adjusts the structure and acid properties of the catalyst by adding metal additives and acidic additives, but the acid structure of the obtained catalyst does not match the pore structure of the catalyst well. In addition, the interaction between the active metal in the catalyst and the support needs to be improved.

[0005] Patent publication number CN103785397A discloses a hydrogenation carbon removal catalyst and its preparation method. The preparation method of the catalyst comprises the following steps: (1) neutralizing an acidic aluminum salt aqueous solution and an alkali metal aluminate aqueous solution, introducing an alkaline precipitant or an alkaline aluminate aqueous solution to adjust the slurry pH to 8.5-9.7, and aging at 150-220°C for 0.1-2 hours; (2) filtering, washing, and drying the aged material in step (1), and then adding 10-40 wt% ammonium aluminum carbonate to form the material; (3) loading the formed material with an active component, drying, and calcining the material to obtain a hydrogenation carbon removal catalyst. Although the catalyst has a high content of pores of 6-10 nm and a certain amount of pores of 100 nm and above, the content of B acid and L acid in the catalyst needs to be further increased, and the interaction between the active metal and the carrier in the catalyst needs to be improved. Summary of the Invention

[0006] In order to solve one of the above technical defects, the present application provides a hydrodenitrogenation and carbon residue removal catalyst and its preparation method and application.

[0007] According to a first aspect of the present application, a method for preparing a hydrodenitrogenation and carbon residue removal catalyst is provided, comprising the following steps: Preparation of unit cell distorted pseudo-boehmite P1; The prepared unit cell distorted pseudo-boehmite P1 and pseudo-boehmite P2 are mixed, with the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P2 being 1:4-1:9; the mixed material is impregnated with a boric acid solution, and the impregnated material is first dried to obtain boron-modified pseudo-boehmite F1; The prepared unit cell distorted pseudo-boehmite P1 and pseudo-boehmite P3 are mixed, with the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P3 being 1:4-2:3; the mixed material is impregnated with a phosphorus-containing solution, and the impregnated material is subjected to a second drying to obtain phosphorus-modified pseudo-boehmite F2; The boron-modified pseudo-boehmite F1 is subjected to a first rolling ball forming process to obtain an alumina support precursor; The prepared alumina support precursor is mixed with the prepared phosphorus-modified pseudo-boehmite F2, with the mass ratio of the phosphorus-modified pseudo-boehmite F2 to the alumina support precursor being greater than 10:1, and then the mixed material is subjected to a second ball forming process, and the formed material is subjected to a third drying process and a first calcination process to obtain an alumina support; The alumina carrier prepared is impregnated with an impregnation solution containing active components, and the impregnated material is dried for the fourth time and calcined for the second time to obtain a hydrodenitrogenation and carbon residue removal catalyst intermediate; The prepared hydrodenitrogenation and carbon residue removal catalyst intermediate is placed in an autoclave, and urea solution I is added to the autoclave and mixed evenly. The mass ratio of the hydrodenitrogenation and carbon residue removal catalyst intermediate to the urea solution I is 1:2 to 1:10. The mixture is then hydrothermally treated, and the hydrothermally treated material is washed, dried for the fifth time, and calcined for the third time to prepare the hydrodenitrogenation and carbon residue removal catalyst.

[0008] Preferably, the preparation of the unit cell distorted pseudo-boehmite P1 specifically includes the following steps: performing a fourth calcination on aluminum nitrate to obtain an amorphous aluminum oxide compound, crushing the obtained amorphous aluminum oxide compound and placing it in an autoclave, adding urea solution II to the autoclave and mixing them evenly, the mass ratio of the amorphous aluminum oxide compound to the urea solution II is 1:2~1:10, and then the mixed material is subjected to low-temperature hydrothermal treatment and high-temperature hydrothermal treatment in sequence. The material after the two hydrothermal treatments is filtered, washed, and dried for the sixth time to obtain the unit cell distorted pseudo-boehmite P1.

[0009] Preferably, in the preparation method of the unit cell distorted pseudo-boehmite P1, the fourth calcination temperature is 450-600°C, the fourth calcination time is 4-8h, the particle size of the amorphous aluminum oxide compound after crushing treatment is less than 20μm, the concentration of urea in the urea solution II is 5.5wt%-10.5wt%, the temperature of the low-temperature hydrothermal treatment is 90-130°C, the time of the low-temperature hydrothermal treatment is 1-4h, the temperature of the high-temperature hydrothermal treatment is 150-200°C, the time of the high-temperature hydrothermal treatment is 4-8h, the sixth drying temperature is 100-160°C, and the sixth drying time is 6-10h.

[0010] Preferably, the morphology of the prepared unit cell distorted pseudo-boehmite P1 is curved lamellar, and the curved lamellar particle size is 100-500 nm; the (020) crystal plane spacing of the unit cell distorted pseudo-boehmite P1 is reduced by 0.3%-1.7% compared with the (020) crystal plane spacing of SB powder.

[0011] Preferably, the most probable pore diameter of the pseudo-boehmite P2 is 6-12 nm; the most probable pore diameter of the pseudo-boehmite P3 is 10-17.5 nm.

[0012] Preferably, the boron content in the boric acid solution is 2.5-6.5 g / 100 mL in terms of elemental boron; and the phosphorus content in the phosphorus-containing solution is 4.5-9.5 g / 100 mL in terms of elemental phosphorus.

[0013] More preferably, the phosphorus-containing solution is one or more of phosphoric acid solution, ammonium phosphate solution, ammonium monohydrogen phosphate solution, and ammonium dihydrogen phosphate solution.

[0014] Preferably, the impregnation solution containing the active component is a solution containing a Group VIB metal and a Group VIII metal, the Group VIB metal content as oxide is 15.5-20.5 g / 100 mL, and the Group VIII metal content as oxide is 3.5-5.5 g / 100 mL; the urea concentration in the urea solution I is 11.5 wt%-18.5 wt%; the hydrothermal treatment temperature is 150-200° C., and the hydrothermal treatment time is 10-16 h.

[0015] According to a second aspect of the present application, a hydrodenitrogenation and carbon residue removal catalyst is provided, which is prepared according to any of the above-mentioned methods for preparing the hydrodenitrogenation and carbon residue removal catalyst.

[0016] According to a third aspect of the present application, there is provided the use of the above-mentioned hydrodenitrogenation and carbon residue removal catalyst in a heavy oil hydrotreating process.

[0017] The present application provides a method for preparing a hydrodenitrification and carbon removal catalyst. Compared to existing technologies, this method has the following technical advantages: The alumina support prepared using distorted pseudo-boehmite as a partial raw material can increase the surface defect content of the alumina support, thereby improving catalyst activity. Furthermore, the pore structure formed by the calcined distorted pseudo-boehmite facilitates the reaction and diffusion of colloidal and asphaltene structural units after depolymerization and side chain cleavage, thereby improving the catalyst's resistance to carbon deposition. Furthermore, during the preparation of the alumina support, pseudo-boehmite with different average pore sizes is used as the raw material for the core and shell layers, resulting in a larger average pore size in the shell layer of the resulting hydrodenitrification and carbon removal catalyst. This pore structure facilitates the diffusion of reactant molecules into the catalyst interior. Furthermore, the core and shell layers of the catalyst are modified with different elements, resulting in a higher L-acid content in the shell layer, a higher B acid (Brønsted acid) content in the core layer, and an appropriate L-acid (Lewis acid) content. This catalyst exhibits high hydrodenitrification and carbon removal activity. In addition, immersing the hydrodenitrogenation and carbon residue removal catalyst intermediate in a urea solution for hydrothermal treatment can effectively improve the interaction between the active metal and the carrier in the hydrodenitrogenation and carbon residue removal catalyst. At the same time, flaky particles are formed on the outer surface of the catalyst. The flaky particles accumulate to form open channels, allowing reactants to quickly enter the interior of the hydrodenitrogenation and carbon residue removal catalyst to participate in the reaction, thereby improving the catalyst activity.

[0018] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the contents indicated in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is an SEM image of the unit cell distorted pseudo-boehmite P1 prepared in Example 1; Figure 2 This is a SEM image of the hydrodenitrogenation and carbon residue removal catalyst prepared in Example 1; Figure 3 XRD spectra of the unit cell distorted pseudo-boehmite P1 and SB powder prepared in Example 1; Figure 4 This is an SEM image of the pseudo-boehmite prepared in Comparative Example 1; Figure 5 This is an SEM image of the comparative catalyst prepared in Comparative Example 2; Figure 6 This is the SEM image of the comparative catalyst prepared in Comparative Example 3. DETAILED DESCRIPTION

[0020] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0021] Unless otherwise specified, the reagents and materials used in the examples are commercially available. The testing methods used in the following examples are all conventional methods in the art, unless otherwise noted. In this application, wt% represents mass fraction. SB (sasol boehmite) powder is a high-quality, high-purity pseudo-boehmite developed by Sasol, Germany, using high-purity aluminum and higher alcohols as raw materials.

[0022] Sample microstructure characterization: Scanning electron microscopy (SEM) was used to characterize the sample microstructure.

[0023] Characterization of sample phase structure: X-ray diffractometer is used to characterize the sample phase structure.

[0024] The formula for calculating the percentage reduction in interplanar spacing, δ, is: δ = (d1 - d2) / d1; where d1 is the (020) interplanar spacing of the SB powder, and d2 is the (020) interplanar spacing of the prepared sample. The (020) plane corresponds to the characteristic peak at 2θ of 11.1°-17.5° in the XRD spectrum. The interplanar spacing of the SB powder and the prepared sample is calculated using Bragg's law: nλ = 2d.sinθ, where n is an integer representing the diffraction order; λ is the wavelength of the incident X-ray; and θ is the diffraction angle, i.e., the angle between the incident beam and the interplanar plane.

[0025] The average pore diameter of the outer and inner layers of the catalyst is determined by first using the low-temperature nitrogen adsorption-desorption method (BET). A certain amount of sample is then placed in a catalyst abrasion tester for grinding. When the sample particle size is reduced to a certain level, the weight loss is measured and the pore structure is re-evaluated. Based on the relationship that the total pore volume and specific surface area of ​​the sample are equal to the sum of the individual components, the pore volume and specific surface area of ​​the ground-away portion can be calculated, and the average pore diameter can then be calculated. A total of 40-80 samples are tested during this experiment.

[0026] Method for determining the Br and L acids in the catalyst shell and core: First, determine the Br and L acids in the catalyst using pyridine adsorption-desorption infrared spectroscopy. Then, place a certain amount of sample in a catalyst abrasion tester for grinding. When the sample particle size is reduced to a certain level, measure the sample weight loss and re-measure the Br and L acids. Since the total Br and L acids in the sample are equal to the sum of each component, the Br and L acids in the ground-away portion can be calculated. The test involves measuring 40-80 samples.

[0027] In response to some problems existing in the prior art, the present application provides a method for preparing a hydrodenitrogenation and carbon residue removal catalyst, comprising the following steps: (1) Preparation of unit cell distorted pseudo-boehmite P1; specifically comprising the following steps: S1. placing aluminum nitrate in a crucible and performing a fourth calcination to obtain an amorphous aluminum oxide compound (i.e., amorphous aluminum oxide); wherein the fourth calcination temperature is 450-600° C., and the fourth calcination time is 4-8 hours; S2. The prepared amorphous aluminum oxide compound is crushed and placed in an autoclave, wherein the particle size of the crushed amorphous aluminum oxide compound is less than 20 μm, and a urea solution II having a urea concentration of 5.5 wt% to 10.5 wt% is added to the autoclave, and magnetic stirring is performed for 10 minutes to uniformly mix; wherein the mass ratio of the amorphous aluminum oxide compound to the urea solution II is 1:2 to 1:10, and the autoclave is lined with polytetrafluoroethylene; S3. The autoclave is sealed, and then the mixed materials are subjected to low-temperature hydrothermal treatment and high-temperature hydrothermal treatment in sequence; wherein the temperature of the low-temperature hydrothermal treatment is 90-130° C., the time of the low-temperature hydrothermal treatment is 1-4 hours, and the temperature of the high-temperature hydrothermal treatment is 150-200° C., and the time of the high-temperature hydrothermal treatment is 4-8 hours. During the low-temperature hydrothermal treatment, the treatment temperature is low and the time is short, and the amorphous aluminum oxide compound first slowly forms unit cell distorted pseudo-boehmite nuclei in the system; during the high-temperature hydrothermal treatment, the unit cell distorted pseudo-boehmite nuclei continue to grow with amorphous aluminum oxide as raw material, facilitating the subsequent formation of the final unit cell distorted pseudo-boehmite; S4. Filtering, washing, and drying the material after the two hydrothermal treatments for the sixth time to obtain unit cell distorted pseudo-boehmite P1, wherein the sixth drying temperature is 100-160° C., and the sixth drying time is 6-10 hours.

[0028] (2) The unit cell distorted pseudo-boehmite P1 and the pseudo-boehmite P2 obtained in step (1) are uniformly mixed, and the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P2 is controlled, and the mixed material is impregnated with a boric acid solution in a saturated impregnation manner, and the amount of boric acid solution used is such that the mixed material is adsorbed saturated. The impregnated material is subjected to a first drying to obtain a boron-modified pseudo-boehmite F1; wherein the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P2 is 1:4-1:9; the pseudo-boehmite P2 has a granular morphology and a most probable pore size of 6-12 nm; the boron content in the boric acid solution is 2.5-6.5 g / 100 mL in terms of elemental boron; the first drying temperature is 100-160° C., and the first drying time is 1-6 h.

[0029] (3) uniformly mixing the unit cell distorted pseudo-boehmite P1 and the pseudo-boehmite P3 obtained in step (1), and controlling the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P3, impregnating the mixture with a phosphorus-containing solution in a saturated impregnation manner, and using an amount of phosphoric acid solution such that the mixture is adsorbed saturated, and subjecting the impregnated material to a second drying to obtain phosphorus-modified pseudo-boehmite F2; wherein the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P3 is 1:4-2:3; the pseudo-boehmite P3 is granular in morphology, and has a most probable pore size of 10-17.5 nm; the phosphorus content in the phosphorus-containing solution is 4.5-9.5 g / 100 mL in terms of elemental phosphorus, the second drying temperature is 100-160° C., and the second drying time is 1-6 h; the phosphorus-containing solution is one or more of a phosphoric acid solution, an ammonium phosphate solution, an ammonium monohydrogen phosphate solution, and an ammonium dihydrogen phosphate solution.

[0030] (4) The boron-modified pseudo-boehmite F1 obtained in step (2) is placed in a rotary disc forming machine, the inclination angle and rotation speed of the rotary disc are adjusted, and an appropriate amount of 0.5% acetic acid aqueous solution is sprayed onto the material in the rotary disc to perform a first ball forming, thereby obtaining an alumina carrier precursor; wherein the operating conditions of the rotary disc forming machine for the first ball forming are: the inclination angle of the rotary disc is 30-75°, the rotation speed of the rotary disc is 10-40 rpm, and the forming time is 45-90 min. In specific implementation, the amount of acetic acid aqueous solution used depends on the forming effect, and it is sufficient to meet the effect.

[0031] (5) The alumina carrier precursor prepared in step (4) is mixed with the phosphorus-modified pseudo-boehmite F2 prepared in step (3), and the mass ratio of the phosphorus-modified pseudo-boehmite F2 to the alumina carrier precursor is greater than 10:1. The mixed material is then placed in a turntable forming machine, the inclination angle and the rotation speed of the turntable are adjusted, and a second ball forming is performed. The formed material is subjected to a third drying and a first roasting to obtain an alumina carrier; wherein the operating conditions of the turntable forming machine for the second ball forming are: the inclination angle of the turntable is 30-75°, the rotation speed of the turntable is 10-40 rpm, and the molding time is 30-60 min; the third drying temperature is 100-160°C, and the third drying time is 1-8 h; the first roasting temperature is 450-650°C, and the first roasting time is 2-8 h.

[0032] (6) The alumina carrier prepared in step (5) is placed in a spray impregnation drum, and the alumina carrier prepared in step (5) is sprayed and impregnated with an impregnation solution containing active components in a saturated impregnation manner. The impregnated material is subjected to a fourth drying and a second roasting to obtain a hydrodenitrogenation and carbon removal catalyst intermediate; wherein the impregnation solution containing active components is a solution containing a VIB group metal and a VIII group metal, the VIB group metal content is 15.5-20.5 g / 100 mL in terms of oxide, and the VIII group metal content is 3.5-5.5 g / 100 mL in terms of oxide; the VIB group metal is Mo and / or W, and the VIII group metal is Ni and / or Co; the fourth drying temperature is 100-160° C., and the fourth drying time is 6-10 h; the second roasting temperature is 450-550° C., and the second roasting time is 4-6 h.

[0033] (7) The hydrodenitrogenation and carbon removal catalyst intermediate prepared in step (6) is placed in an autoclave, and urea solution I with a urea concentration of 11.5wt%-18.5wt% is added to the autoclave and mixed evenly. The mass ratio of the hydrodenitrogenation and carbon removal catalyst intermediate to the urea solution I is 1:2-1:10. The mixture is then hydrothermally treated, and the hydrothermally treated material is washed, dried for the fifth time, and calcined for the third time to prepare a hydrodenitrogenation and carbon removal catalyst; wherein the hydrothermal treatment temperature is 150-200°C, and the hydrothermal treatment time is 10-16h; the fifth drying temperature is 100-160°C, and the fifth drying time is 6-10h; the third calcination temperature is 450-550°C, and the third calcination time is 4-6h.

[0034] In practice, saturated impregnation can be replaced with equal-volume impregnation or excess-volume impregnation. Equal-volume impregnation requires that the volume of the support (generally the pore volume) and the volume of the impregnation solution are equal, allowing the solution to completely penetrate the pores. This effectively controls the loading of the active component and facilitates calculation. Excess-volume impregnation requires that the volume of the impregnation solution is greater than that of the support. In this process, after the active component loading on the support reaches adsorption equilibrium, the excess solution is filtered off (rather than evaporated).

[0035] Specifically, the particle size of the amorphous aluminum oxide compound after the pulverization process is less than 10 μm.

[0036] Specifically, the Group VIB metal is Mo, and the Group VIII metal is Ni.

[0037] Specifically, pseudo-boehmite P2 and pseudo-boehmite P3 can be purchased or prepared by existing technologies (such as acid precipitation method, alkali precipitation method, alcohol aluminum hydrolysis method), and the most probable pore diameter of pseudo-boehmite P2 is preferably 8-10 nm, and the most probable pore diameter of pseudo-boehmite P3 is preferably 10-12.5 nm.

[0038] The morphology of the distorted pseudo-boehmite P1 prepared in this application is curved lamellar, with particle sizes ranging from 100 to 500 nm. The (020) interplanar spacing of the distorted pseudo-boehmite P1 is 0.3% to 1.7% smaller than that of SB powder. Furthermore, during the preparation of the distorted pseudo-boehmite in this application, experiments have shown that other aluminum salts, such as aluminum chloride and aluminum sulfate, cannot produce distorted pseudo-boehmite, and this will not be discussed further here.

[0039] The present application uses unit cell distorted pseudo-boehmite as part of the raw material to prepare an alumina carrier, which can increase the content of surface defects of the alumina carrier, thereby improving the activity of the catalyst, and the pore structure accumulated after the unit cell distorted pseudo-boehmite is calcined is conducive to the reaction and diffusion of the colloid and asphaltene structural units after depolymerization and side chain cleavage, thereby improving the catalyst's ability to resist carbon deposition. At the same time, when preparing the alumina carrier, pseudo-boehmite with different average pore diameters is used as the core layer and shell layer raw materials, so that the average pore diameter of the shell layer of the final hydrodenitrogenation and carbon removal catalyst is larger, and the pore structure is conducive to the diffusion of reactant molecules into the interior of the catalyst. In addition, the core layer and shell layer of the catalyst are modified with different elements, so that the L acid content of the catalyst shell layer is higher, the B acid content of the core layer is higher, and the L acid content is appropriate. The catalyst with this structure has higher hydrodenitrogenation and carbon removal activity. In addition, immersing the hydrodenitrogenation and carbon residue removal catalyst intermediate in a urea solution for hydrothermal treatment can effectively improve the interaction between the active metal and the carrier in the hydrodenitrogenation and carbon residue removal catalyst. At the same time, flaky particles are formed on the outer surface of the catalyst. The flaky particles accumulate to form open channels, allowing reactants to quickly enter the interior of the hydrodenitrogenation and carbon residue removal catalyst to participate in the reaction, thereby improving the catalyst activity.

[0040] In order to demonstrate the beneficial effects of the preparation method of the hydrodenitrogenation and carbon residue removal catalyst provided by the present application, the present application is further described below in conjunction with specific examples. Among them, the hydrodenitrogenation and carbon residue removal catalysts Cat-1 to Cat-4 in Examples 1 to 4 are prepared according to the addition ratios and preparation conditions of each raw material specified in Table 1 below, and the unit cell distorted pseudo-boehmite P1-1 to P1-4 in Examples 1 to 4 are prepared according to the specific conditions specified in Table 2 below. In addition to the above examples, the present application also uses data within the range of other preparation conditions (such as the most probable pore size of pseudo-boehmite P2, the temperature and time of the first drying, the temperature and time of the fourth calcination, etc.) to prepare the corresponding unit cell distorted pseudo-boehmite P1 and hydrodenitrogenation and carbon residue removal catalyst. In order to save space, they are not repeated here. In addition, the properties of the unit cell distorted pseudo-boehmite P1 obtained in the examples of the hydrodenitrogenation and carbon residue removal catalyst provided by the present application are shown in Table 2 below.

[0041]

[0042]

[0043] Comparative Example 1 The same method as Example 1 was used, except that the urea solution II in the process of preparing the unit cell distorted pseudo-boehmite P1 in step (1) was replaced with an ammonia solution II of the same concentration to prepare a comparative catalyst Cat-5.

[0044] Comparative Example 2 The same as Example 1, except that the unit cell distorted pseudo-boehmite P1 was not added in step (2) and step (3), and the comparative catalyst Cat-6 was prepared using pseudo-boehmite P2 and P3 as raw materials.

[0045] Comparative Example 3 The same method as Example 1 was used, except that the urea solution I in step (7) was replaced with ammonium carbonate of the same concentration to prepare a comparative catalyst Cat-7.

[0046] In this application, scanning electron microscopy was used to characterize the microstructures of the unit cell distorted pseudo-boehmite and the hydrodenitrification and carbon residue removal catalyst prepared in the examples, and the pseudo-boehmite and comparative catalyst prepared in the comparative examples, and corresponding scanning electron microscope images (SEM images) were obtained. For the purpose of simplicity, this application uses Example 1 and Comparative Examples 1-3 as examples, and provides SEM images of the unit cell distorted pseudo-boehmite P1 prepared in Example 1 and SEM images of the hydrodenitrification and carbon residue removal catalyst, as shown in FIG. Figure 1 and Figure 2 Provided is a SEM image of the pseudo-boehmite prepared in Comparative Example 1, as shown Figure 4 Provides SEM images of the comparative catalysts of Comparative Examples 2 and 3, as shown Figure 5 and Figure 6 shown.

[0047] Depend on Figure 1 As can be seen from Table 2, the morphology of the unit cell distorted pseudo-boehmite P1 provided in Example 1 of the present application is curved lamellar, and the size of the curved lamellar particles is 100-500nm, and the specific surface area is large; Figure 2 It can be seen that the surface particle morphology of the hydrodenitrogenation and carbon residue removal catalyst prepared in Example 1 of the present application is flaky, and the flaky particles are evenly covered on the catalyst surface and form open channels of 100-300nm; Figure 4 It can be seen that the morphology of the pseudo-boehmite P1 provided in Comparative Example 1 is not curved lamellar, but worm-like. This shows that other alkaline solutions except urea solution cannot produce curved lamellar unit cell distorted pseudo-boehmite, such as ammonia solution and ammonium carbonate solution.

[0048] In this application, X-ray diffractometer was used to characterize the physical structure of the unit cell distorted pseudo-boehmite P1 prepared in the embodiment and the pseudo-boehmite prepared in the comparative example, and the corresponding XRD spectra were obtained. For the purpose of simplicity, this application takes Example 1 as an example and provides the XRD spectra of SB powder and the unit cell distorted pseudo-boehmite P1 prepared in Example 1, as shown in FIG. Figure 3 As shown. Figure 3It can be seen that the diffraction peak corresponding to the (020) crystal plane of the unit cell distorted pseudo-boehmite P1 prepared in Example 1 of the present application is shifted compared with the SB powder, further indicating that the prepared pseudo-boehmite is unit cell distorted pseudo-boehmite.

[0049] The present application also calculated the percentage reduction δ of the (020) interplanar spacing of Examples 1 to 4 compared to the SB powder using the XRD spectra of the unit cell distorted pseudo-boehmite P1 and the XRD spectra of the SB powder, as shown in Table 2. As shown in Table 2, the percentage reduction of the (020) interplanar spacing of the unit cell distorted pseudo-boehmite P1 compared to the (020) interplanar spacing of the SB powder is 0.3%-1.7%.

[0050] The surface particle morphology of each hydrodenitrogenation and carbon residue removal catalyst in Examples 1 to 4 of the present application is flaky, and the flaky particles are evenly covered on the catalyst surface and form open channels of 100-300 nm. The surface particle morphology of the comparative catalyst in Comparative Example 2 is granular, such as Figure 5 As shown, it is further proved that in the process of preparing the catalyst, when the unit cell distorted pseudo-boehmite prepared by the present application is not added, the granular particles are packed tightly, which is not conducive to the formation of large pore channels. However, after adding the unit cell distorted pseudo-boehmite prepared by the present application, the pseudo-boehmite particles of different forms can effectively adjust the pore structure of the carrier. The surface particles of the comparative catalyst in Comparative Example 3 are mainly granular, with a small amount of rod-shaped particles covering the surface. The main granular particles are tightly packed and no open pore structure is formed. Figure 6 shown.

[0051] In order to better understand the essence of the present application, the properties and catalytic performance of the hydrodenitrogenation and carbon removal catalysts prepared in Examples 1 to 4 and the comparative catalysts prepared in Comparative Examples 1 to 3 were tested, and the test results are shown in Tables 3 and 4.

[0052]

[0053] As can be seen from Table 3, the shell pores of the hydrodenitrogenation and carbon residue removal catalyst prepared in the embodiment of the present application are larger, and the core pores are second (both are higher than the pores of the reference catalyst). At the same time, the shell L acid content of the hydrodenitrogenation and carbon residue removal catalyst is high, and the core B acid content is high. The acid properties match the pore structure, which is beneficial to desulfurization and carbon residue removal.

[0054] Catalyst performance evaluation: The catalytic performance of the catalysts (Cat-1 to Cat-7) prepared in the above examples and comparative examples was evaluated using the following method: The catalysts prepared in the examples and comparative examples were respectively loaded into a fixed-bed hydrogenation reactor, and a residual oil was used as a raw material (nitrogen content in the raw oil was 0.39 wt%, and residual carbon content was 14.2 wt%). The catalytic performance of the catalysts was evaluated. The reaction conditions were as follows: reaction temperature of 380°C, pressure of 14.5 MPa, liquid hourly volume space velocity of 0.65 h -1 The hydrogen-to-oil volume ratio was 850. After 3000 hours of reaction, the content of each impurity in the generated oil was measured and the impurity removal rate was calculated. The evaluation results are shown in Table 4. Among them, the denitrification rate and residual carbon removal rate were calculated according to the following formula: Denitrification rate % = (1-nitrogen content in product / nitrogen content in feed oil) × 100%; Relative denitrification rate: Determine the denitrification rate of a certain catalyst, define its relative denitrification rate as 100%, and the nitrogen removal rate of other catalysts / the nitrogen removal rate of the defined catalyst × 100% is the relative denitrification rate; Carbon removal rate % = (1-carbon content in product / carbon content in feed oil) × 100%; Relative carbon removal rate: Determine the carbon removal rate of a certain catalyst, define its relative carbon removal rate as 100%, and the carbon removal rate of other catalysts / defined catalyst carbon removal rate × 100% is the relative carbon removal rate.

[0055]

[0056] From the data in Table 4, it can be seen that the hydrodenitrogenation and carbon residue removal catalyst prepared by the method of the present application has high hydrodenitrogenation and carbon residue removal activity after continuous operation for 3000 hours, indicating that the catalyst prepared by the present application has high hydrodenitrogenation and carbon residue removal activity and good stability.

[0057] In summary, the hydrodenitrogenation and carbon removal catalyst prepared in this application has a large average pore size in the shell layer, a high Br content in the core layer, and a suitable interaction between the active metal and the support. Furthermore, this catalyst exhibits high hydrodenitrogenation and carbon removal activity and excellent stability, making it widely applicable in the field of heavy oil hydroprocessing.

[0058] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0059] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0060] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for preparing a hydrodenitrogenation and carbon residue removal catalyst, characterized in that: The following steps are involved: Preparation of unit cell distorted pseudo-boehmite P1; The prepared unit cell distorted pseudo-boehmite P1 and pseudo-boehmite P2 are mixed, with the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P2 being 1:4-1:9; the mixed material is impregnated with a boric acid solution, and the impregnated material is first dried to obtain boron-modified pseudo-boehmite F1; The prepared unit cell distorted pseudo-boehmite P1 and pseudo-boehmite P3 are mixed, with the mass ratio of the unit cell distorted pseudo-boehmite P1 to the pseudo-boehmite P3 being 1:4-2:3; the mixed material is impregnated with a phosphorus-containing solution, and the impregnated material is subjected to a second drying to obtain phosphorus-modified pseudo-boehmite F2; The boron-modified pseudo-boehmite F1 is subjected to a first rolling ball forming process to obtain an alumina support precursor; The prepared alumina support precursor is mixed with the prepared phosphorus-modified pseudo-boehmite F2, with the mass ratio of the phosphorus-modified pseudo-boehmite F2 to the alumina support precursor being greater than 10:1, and then the mixed material is subjected to a second ball forming process, and the formed material is subjected to a third drying process and a first calcination process to obtain an alumina support; The alumina carrier prepared is impregnated with an impregnation solution containing active components, and the impregnated material is dried for the fourth time and calcined for the second time to obtain a hydrodenitrogenation and carbon residue removal catalyst intermediate; The prepared hydrodenitrogenation and carbon residue removal catalyst intermediate is placed in an autoclave, and urea solution I is added to the autoclave and mixed evenly. The mass ratio of the hydrodenitrogenation and carbon residue removal catalyst intermediate to the urea solution I is 1:2 to 1:

10. The mixture is then hydrothermally treated, and the hydrothermally treated material is washed, dried for the fifth time, and calcined for the third time to prepare the hydrodenitrogenation and carbon residue removal catalyst.

2. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 1, wherein: The preparation of the unit cell distorted pseudo-boehmite P1 specifically includes the following steps: Aluminum nitrate is calcined for the fourth time to obtain an amorphous aluminum oxide compound. The obtained amorphous aluminum oxide compound is crushed and placed in an autoclave. Urea solution II is added to the autoclave and mixed evenly. The mass ratio of the amorphous aluminum oxide compound to the urea solution II is 1:2 to 1:

10. The mixed material is then subjected to low-temperature hydrothermal treatment and high-temperature hydrothermal treatment in sequence. The material after the two hydrothermal treatments is filtered, washed, and dried for the sixth time to obtain unit cell distorted pseudo-boehmite P1.

3. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 2, wherein: In the preparation method of the unit cell distorted pseudo-boehmite P1, the fourth calcination temperature is 450-600°C, the fourth calcination time is 4-8 hours, the particle size of the amorphous aluminum oxide compound after pulverization is less than 20 μm, the concentration of urea in the urea solution II is 5.5wt%-10.5wt%, the temperature of the low-temperature hydrothermal treatment is 90-130°C, the time of the low-temperature hydrothermal treatment is 1-4 hours, the temperature of the high-temperature hydrothermal treatment is 150-200°C, the time of the high-temperature hydrothermal treatment is 4-8 hours, the sixth drying temperature is 100-160°C, and the sixth drying time is 6-10 hours.

4. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 2, wherein: The prepared unit cell distorted pseudo-boehmite P1 has a curved lamellar morphology, and the curved lamellar particle size is 100-500 nm; the (020) crystal plane spacing of the unit cell distorted pseudo-boehmite P1 is reduced by 0.3%-1.7% compared with the (020) crystal plane spacing of SB powder.

5. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 1, wherein: The most probable pore diameter of the pseudo-boehmite P2 is 6-12 nm; the most probable pore diameter of the pseudo-boehmite P3 is 10-17.5 nm.

6. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 1, wherein: The boron content in the boric acid solution is 2.5-6.5 g / 100 mL in terms of elemental boron; and the phosphorus content in the phosphorus-containing solution is 4.5-9.5 g / 100 mL in terms of elemental phosphorus.

7. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 6, wherein: The phosphorus-containing solution is one or more of phosphoric acid solution, ammonium phosphate solution, ammonium monohydrogen phosphate solution, and ammonium dihydrogen phosphate solution.

8. The method for preparing a hydrodenitrogenation and carbon residue removal catalyst according to claim 1, wherein: The impregnation solution containing the active component is a solution containing a Group VIB metal and a Group VIII metal, wherein the content of the Group VIB metal as oxide is 15.5-20.5 g / 100 mL, and the content of the Group VIII metal as oxide is 3.5-5.5 g / 100 mL; The concentration of urea in the urea solution I is 11.5wt%-18.5wt%; the hydrothermal treatment temperature is 150-200°C, and the hydrothermal treatment time is 10-16h.

9. A hydrodenitrogenation and carbon residue removal catalyst, characterized in that: The catalyst is prepared according to the method for preparing the hydrodenitrogenation and carbon residue removal catalyst according to any one of claims 1 to 8.

10. Use of the hydrodenitrogenation and carbon residue removal catalyst according to claim 9 in a heavy oil hydrotreating process.

Images