Heavy oil hydrodemetallization catalyst and application thereof
By preparing an alumina support with a low micropore ratio and loading specific metal components, the problem of rapid deactivation of heavy oil hydrotreating catalysts due to micropore blockage was solved, achieving efficient demetallization and desulfurization of heavy oil and extending catalyst life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-07-08
- Publication Date
- 2026-07-14
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Figure BDA0003736564880000151 
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of petroleum refining and relates to a heavy oil hydrogenation catalyst and its application. More specifically, it relates to a heavy oil hydrogenation catalyst prepared from a support with a low proportion of small pores and its application in heavy oil demetallization. Background Technology
[0002] With my country's "carbon peaking and carbon neutrality" goals proposed at the 2020 UN General Assembly, environmental regulations will be further strengthened. However, in recent years, the trend of high sulfur content and heavy, inferior quality in global crude oil resources has intensified, with huge reserves of unconventional crude oils such as heavy oil, extra-heavy oil, and oil sands bitumen, increasing the difficulty of crude oil processing. The efficient and clean conversion of heavy oil feedstocks, especially residue oil, is the core of crude oil utilization. Among various routes, the fixed-bed residue hydrotreating process can remove impurities such as metals, sulfur, and nitrogen from residue oil, achieving the lightening of heavy oil, and is currently the most widely used residue oil processing technology. Currently, one of the main problems facing fixed-bed residue hydrotreating is the deposition of metals such as Fe, Ca, Ni, and V on the catalyst, clogging the catalyst channels, leading to increased pressure drop in the reactor bed and rapid catalyst deactivation, limiting the processing of inferior feedstocks and affecting the unit's operating cycle. Therefore, the removal of metals such as Ni and V is a crucial step in the residue hydrotreating process. Developing hydrodemetallization catalysts with high demetallization activity and strong metal-containing capacity can effectively extend the service life of downstream catalysts, thereby protecting downstream catalysts and extending the unit's operating cycle.
[0003] The pore distribution of the hydrodemetallization catalyst support has a significant impact on the catalyst's activity and stability. On the one hand, the support provides channels for the reaction, promoting mass transfer and diffusion of reactant molecules and better accommodating the removed metal; on the other hand, it improves the dispersion of the active metal on the support. Effectively reducing the proportion of pores smaller than 10 nm in the support is beneficial for the diffusion of large molecules such as residual oil, and can prevent the adsorption of large amounts of impregnated metal within the small pores due to the microporous effect, thus improving the utilization rate of the active metal.
[0004] CN112337452A discloses a method for preparing a catalyst support for hydrodemetallization of residue oil. The method includes: firstly, preparing an alumina support by extruding, drying, and calcining conventional alumina dry adhesive; then, subjecting the alumina support to hydrothermal treatment under a medium atmosphere to regulate its pore structure, thereby obtaining a hydrodemetallization catalyst support for residue oil with a suitable pore structure. This method avoids excessive reliance on the properties of alumina dry adhesive and the introduction of pore-forming agents during extrusion, greatly reducing the difficulty and cost of preparing the hydrodemetallization catalyst support for residue oil.
[0005] CN112717947 discloses a boron-containing catalyst and its preparation method. Yeast is dissolved in an aqueous solution and mixed with starch to form a mixture. This mixture is then mixed with a boron-containing solution to prepare a pre-impregnation solution. A physical pore-expanding agent is introduced into the pre-impregnation solution, which is then mixed with boehmite powder. After molding, drying, and calcination, an alumina support is obtained. The alumina support is impregnated with a hydrogenation active component, and after drying and calcination, a boron-containing catalyst is obtained. The hydrogenation catalyst prepared by this method shows significantly improved activity and stability.
[0006] CN109277108A discloses a method for preparing a silicon-containing hydrogenation demetallization catalyst. A first physical pore-expanding agent and a second physical pore-expanding agent that have been in contact with a silicon-containing solution are mixed with boehmite to form a silicon-containing alumina support. The support is then impregnated with a hydrogenation active component to obtain a silicon-containing hydrogenation demetallization catalyst. The catalyst prepared by this method has high mechanical strength, a suitable pore structure, and a moderate interaction between the active component and the support. It also exhibits high hydrogenation demetallization activity and activity stability.
[0007] CN106140122A discloses a method for preparing a boron-containing hydrodemetallization catalyst. The method involves impregnating a pore-expanding agent with a hydrogenation active component impregnation solution and a boron-containing solution, respectively. Then, a second physical pore-expanding agent is impregnated with both the hydrogenation active component impregnation solution and the boron-containing solution. After drying, the two physical pore-expanding agents are mixed with boehmite, an extrusion aid, etc., to obtain a modified alumina support. The modified alumina support is then impregnated with the hydrogenation active component impregnation solution, and after drying and calcination, the boron-containing hydrodemetallization catalyst is obtained. The catalyst prepared by this method has a relatively high content of active metal in macropores and a relatively low content in micropores, significantly improving the utilization rate of macropores. This hydrodemetallization catalyst exhibits high activity and long-term operational stability.
[0008] Existing technologies have produced a series of alumina supports with specific pore distributions, but there is limited research on alumina supports and preparation methods that can reduce the proportion of small pores (e.g., pores smaller than 4 nm) or smaller than 10 nm relative to the total pore volume during the support preparation stage. It should be noted that the information disclosed in the foregoing background section is only for enhancing the understanding of the background of this invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0009] To address the problems existing in the prior art, this invention provides a hydrodemetallization catalyst with a low pore size ratio. When used for heavy oil hydrodemetallization, it significantly improves the hydrodemetallization activity, and its desulfurization and residual carbon removal activities are also significantly higher than those of existing hydrodemetallization catalysts. Specifically, this invention includes the following:
[0010] This invention provides a heavy oil hydrodemetallization catalyst, comprising a support and a metal component supported on the support, wherein the hydrodemetall component is selected from one or more Group VIB and Group VIII metals, and the content of the hydrodemetall component, based on oxides and the total weight of the catalyst, is 0.3-20% by weight; the support has a bimodal pore structure with a pore volume of 0.9-1.6 mL / g and a specific surface area of 100-400 m². 2 / g, characterized by mercury porosimetry, the carrier exhibits a bimodal pore distribution with diameters of 5-20nm and 100-500nm. The pore volume of pores with diameters of 5-20nm accounts for 50-80% of the total pore volume, the pore volume of pores with diameters of 100-500nm accounts for 19-40% of the total pore volume, and the pore volume of pores with diameters below 10nm does not exceed 20% of the total pore volume; the preparation of the alumina carrier includes the following steps: (1) mixing the raw materials to obtain a plastic body, the raw materials including those containing pseudo (1) Hydrated alumina P1 of boehmite, extrusion aid, adhesive solvent and water; (2) Molding, drying and calcining the above plastic body; characterized in that the calcination includes anaerobic calcination and aerobic calcination, wherein the conditions for anaerobic calcination include: the calcination atmosphere is a gas atmosphere without oxidizing gases, the temperature is 450-1200℃, and the time is 2-10h; and the conditions for aerobic calcination include: the calcination atmosphere is a gas atmosphere containing oxidizing gases, the temperature is 300-900℃, and the time is 2-10h.
[0011] The present invention also provides a method for hydrotreating heavy oil, comprising contacting the feedstock oil with a hydrotreating catalyst under hydrotreating conditions, wherein the hydrotreating catalyst is any one of the heavy oil hydrotreating demetallization catalysts described in the present invention.
[0012] Compared with the prior art, the proportion of the pore volume of the heavy oil hydrodemetallization catalyst provided by the present invention is significantly reduced, especially the proportion of the pore volume of pores with diameters of 4nm and 10nm and below to the total pore volume is significantly reduced. When used for heavy oil hydrodemetallization, the demetallization activity is significantly improved, and the desulfurization activity and residual carbon removal activity are also significantly improved. Detailed Implementation
[0013] First, it should be noted that the endpoints and any values of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0014] The hydrogenation metal components and their contents in the catalyst of the present invention can be conventionally selected in the art, preferably including at least one Group VIB metal and at least one Group VIII metal. Based on the total weight of the catalyst and the oxide content, the content of the Group VIB metal is 0.5-12% by weight and the content of the Group VIII metal is 0.3-9% by weight. More preferably, the Group VIB metal is selected from molybdenum and / or tungsten, and the Group VIII metal is cobalt and / or nickel. Based on the catalyst and the oxide content, the content of the Group VIB metal is 5-12% by weight and the content of the Group VIII metal is 0.4-9% by weight.
[0015] The alumina support in the hydrodemetallization catalyst of the present invention has specific pore characteristics, with a low percentage of small pores in the total pore volume. Preferably, characterized by mercury porosimetry, the pore volume of pores with a diameter of less than 10 nm does not exceed 20% of the total pore volume, more preferably not more than 17%; more preferably, the pore volume of pores with a diameter of less than 4 nm does not exceed 5.5% of the total pore volume, more preferably not more than 5%.
[0016] According to the catalyst provided by the present invention, the method for preparing the alumina support mainly includes two steps: (1) mixing raw materials to prepare a plastic body; (2) molding, drying and calcining the plastic body, wherein calcination includes anaerobic calcination and aerobic calcination. The conditions for anaerobic calcination include: the calcination atmosphere is a gaseous atmosphere without oxidizing gases, the temperature is 450-1000℃, preferably 500-900℃, 600-800℃, and the time is 1-10h, preferably 2-8h; the conditions for aerobic calcination include: the calcination atmosphere is a gaseous atmosphere containing oxidizing gases, the temperature is 350-900℃, preferably 450-850℃, 500-750℃, etc., and the time is 1-10h, preferably 2-8h.
[0017] According to the alumina carrier preparation process of the present invention, the raw materials for preparing the plastic body in step (1) include hydrated alumina P1 containing boehmite, extrusion aid, adhesive, and water. Provided that the final carrier meets the requirements of the present invention, the present invention does not have special requirements for the boehmite P1 in the raw materials; it can be any boehmite prepared by existing technology, or a mixture of boehmite and any hydrated alumina. The hydrated alumina is selected from one or more of alumina monohydrate, alumina trihydrate, and amorphous hydrated alumina. In the present invention, the pore volume, specific surface area, and most probable pore size of the hydrated alumina containing boehmite are characterized by nitrogen physical adsorption-desorption instrumentation after calcining the hydrated alumina P1 containing boehmite at 600°C for 4 hours. Preferably, the pore volume of P1 is 0.9–1.4 mL / g, more preferably 0.95–1.35 mL / g, and the specific surface area is 100–450 μm. 2 / gram, further preferably 200-350 meters 2 / gram, with a most likely pore diameter of 8-30 nm, more preferably 10-25 nm. Characterized by X-ray diffraction, the hydrated alumina P1 containing boehmite has a boehmite content of not less than 50%, preferably 50%-95%, more preferably not less than 60%-90%; a gibbsite content of not more than 20%, preferably 2%-20%; and the balance is amorphous alumina.
[0018] According to the present invention, the mixing and molding processes in the preparation of the alumina carrier can be carried out by conventional methods, such as spray drying, ball rolling, tableting, and extrusion molding, or a combination of several methods. Depending on the requirements, various easily manipulated molded products can be produced, such as microspheres, spheres, honeycomb shapes, bird's nest shapes, tablets, or strips (clover-shaped, butterfly-shaped, cylindrical, etc.). During molding, for example, in extrusion molding, to ensure smooth molding, water, extrusion aids, and / or adhesives, with or without pore expanders, can be added to the mixture, followed by extrusion molding, drying, and calcination. In this invention, the types and amounts of extrusion aids and adhesives are known to those skilled in the art. For example, common extrusion aids can be selected from one or more of guar gum powder, methylcellulose, starch, polyvinyl alcohol, and polyethylene glycol. The adhesives can be inorganic acids and / or organic acids. Inorganic acids can be nitric acid, boric acid, phosphoric acid, etc., and organic acids can be common carboxylic acids, or aminocarboxylic acids, hydroxycarboxylic acids, etc. The pore expanders can be one or more of starch, synthetic cellulose, polyols, and surfactants.
[0019] The plastic body is dried using conventional methods and conditions in the art. Generally, the drying conditions can be a temperature of 100-250°C and a time of 2-10 hours.
[0020] The inventors of this invention discovered that during the calcination process, high-temperature calcination under an inert atmosphere deoxidizes the carbon-containing precursor. The carbonized organic carbon skeleton forms CO bonds with oxygen on the surface of boehmite, causing specific sintering between boehmite particles during subsequent air calcination. This increases pore volume while simultaneously increasing pore size and pore concentration, significantly reducing the proportion of small-diameter pores that are detrimental to macromolecular diffusion and reactions, especially those with diameters below 4 nm or 10 nm. Through combined anaerobic and aerobic calcination, the proportion of pore volume with smaller diameters in the alumina carrier is significantly reduced, particularly the proportion of pore volume with diameters not exceeding 4 nm and 10 nm.
[0021] In this invention, the oxygen-free calcination in the alumina carrier preparation step (2) refers to the calcination atmosphere not containing oxidizing gases, preferably an inert atmosphere, such as one or more selected from nitrogen, helium, and argon; the oxygen-containing calcination refers to the calcination atmosphere containing oxidizing gases, most commonly oxygen, preferably a mixture of oxygen and other gases, such as air, or air diluted with nitrogen, or a mixture of oxygen and air, etc. Generally, the volume content of oxidizing gases can be 5% to 50% by volume, preferably air.
[0022] To achieve a better reduction in the proportion of small holes, the heating rate for both aerobic and anaerobic roasting is preferably 50℃ / hour to 600℃ / hour. Furthermore, multiple aerobic and anaerobic roasting processes can be performed as needed, preferably alternating between them, with the final process being aerobic roasting.
[0023] The inventors of this invention further discovered that adding hydrated alumina P2 containing boehmite to the material before molding can better adjust the water-to-powder ratio of the molding material, reduce the extrusion pressure during molding, thereby reducing the loss of carrier pore volume and changes in pore structure during molding, especially beneficial to the formation of macropores during carrier molding, further reducing the content of micropores. Therefore, this invention preferably includes a step of adding and mixing hydrated alumina P2 containing boehmite before molding the plastic body in step (2), wherein, on a dry basis, the weight ratio of P1 to P2 is 70-97:3-30; preferably, the weight ratio of P1 to P2 is 80-95:5-20. The boehmite-containing powder P2 can be any boehmite powder or a mixture of several boehmite powders, and can be P1 or a modified version of P1. When P2 is a modified P1, the methods for modifying P1 to P2 include the following: (1) calcining the hydrated alumina P1 containing boehmite to obtain powder P2. (2) molding and drying the hydrated alumina P1 containing boehmite, and then grinding and sieving all or part of it to obtain powder P2. The drying conditions include a temperature of 100-350℃ and a time of 1-10 hours. (3) drying and calcining the molded material obtained in (2) at a temperature of 500-1000℃ for 1-10 hours, and then grinding and sieving all or part of it to obtain powder P2. (4) mixing one or more of the modified materials obtained in (1), (2), and (3) to obtain P2. More preferably, P2 is 100-400 mesh particles in the modified P1.
[0024] According to the catalyst provided by the present invention, any substance that can improve the performance of the support and catalyst provided by the present invention can be introduced during the preparation process, such as various additives, and one or more of the representative additives such as F, P, and B. The additive can be introduced during the preparation of the support or when introducing the hydrogenated metal component. If it is introduced during the preparation of the alumina support, the specific timing of introduction can be as one of the raw materials of the plastic body in step (1), or it can be added together with P2 before molding. The additive is one or more of boron-containing compounds, phosphorus-containing compounds, and fluorine-containing compounds. The amount of additive added is 0.5-10% by weight of P1 on a dry basis, preferably 0.5-5% by weight. The boron-containing compound is preferably one or more of boric acid, boron oxide, and borate, and the phosphorus-containing compound is preferably phosphoric acid, phosphorous acid, phosphate, etc.
[0025] According to the catalyst of the present invention, its preparation method includes the steps of preparing an alumina support and loading a hydrogenated metal component onto the alumina support. Provided that the hydrogenated active metal component can be sufficiently loaded onto the alumina support, the present invention does not particularly limit the loading method; a preferred method is an impregnation method, which includes preparing an impregnation solution containing the metal compound, and then impregnating the alumina support with the solution. The impregnation method is a conventional method, for example, excess liquid impregnation or pore saturation impregnation. The metal-containing compound is selected from one or more of their water-soluble compounds (including compounds soluble in water in the presence of a co-solvent). Taking molybdenum from Group VIB as an example, it can be selected from one or more of molybdenum oxide, molybdate, and ammonium molybdate, with molybdenum oxide, ammonium molybdate, and ammonium molybdate being preferred. Taking tungsten from Group VIB as an example, it can be selected from one or more of tungstate, metatungstate, and ethyl metatungstate, with ammonium metatungstate and ethyl metatungstate being preferred. Taking nickel from Group VIII as an example, it can be selected from one or more of nickel nitrate, nickel acetate, basic nickel carbonate, nickel chloride, and soluble complexes of nickel, with nickel nitrate and basic nickel carbonate being preferred. Taking cobalt from Group VIII as an example, it can be selected from one or more of cobalt nitrate, cobalt acetate, basic cobalt carbonate, cobalt chloride, and soluble complexes of cobalt, with cobalt nitrate and basic cobalt carbonate being preferred.
[0026] After the hydrogenated active metal component is introduced into the support, necessary drying and calcination steps are generally required. The drying and calcination conditions can be conventional conditions in the field, and the specific process will not be described in detail.
[0027] On the other hand, this invention also provides the application of the heavy oil hydrodemetallization catalyst described herein in the treatment of heavy oil, specifically a method for heavy oil hydrotreating, comprising contacting the feedstock oil with the hydrodemetallization catalyst described herein under hydrotreating conditions. The hydrotreating conditions are conventional conditions in the art. In a preferred embodiment, the reaction conditions for hydrotreating are: a reaction temperature of 300-550°C, more preferably 330-480°C, a hydrogen partial pressure of 4-20 MPa, more preferably 6-18 MPa, and a volume hourly space velocity of 0.1-3.0 h⁻¹. -1 Further optimization of 0.15-2 hours -1 The hydrogen-to-oil volume ratio is 200-2500, with a further preferred ratio of 300-2000.
[0028] The heavy oil hydrotreating apparatus of the present invention can be carried out in any reactor sufficient to allow the feedstock to react with the catalyst under hydrotreating reaction conditions, for example, in a fixed-bed reactor, a moving-bed reactor, or a fluidized-bed reactor. According to conventional methods in the art, the hydrotreating catalyst is typically pre-sulfurized with sulfur, hydrogen sulfide, or a sulfur-containing feedstock in the presence of hydrogen at a temperature of 140-370°C before use. This pre-sulfurization can be carried out externally or in situ within the reactor, converting the loaded hydrotreating active metal component into a metal sulfide component.
[0029] The catalyst provided by this invention can be used alone or in combination with other catalysts. This catalyst is particularly suitable for hydrodemetallization of heavy oil, especially low-quality residue oil, in order to provide qualified feedstock for subsequent processes (such as catalytic cracking).
[0030] This invention employs an alumina support with a lower pore content, particularly a pore size ratio of less than 4 nm and a pore size ratio of less than 10 nm. At the same time, while increasing the pore volume of the support, the pore size is increased and the pore concentration is improved, thereby enhancing the diffusion performance of macromolecules on the catalyst. It can be applied to hydrogenation demetallization treatment, and the demetallization performance and the performance of removing other impurities are significantly improved, showing good results and promising application prospects.
[0031] The present invention will be described in detail below with reference to the embodiments, but this does not limit the scope of the invention. Unless otherwise specified, all reagents used in the examples are chemically pure.
[0032] The pseudoboehmite used in the following embodiments:
[0033] P1-1: Dry adhesive powder produced by Yantai Heng Hui Chemical Co., Ltd. (pore volume 1.1 ml / g, specific surface area 260 m²) 2 / g, with a most accessible pore diameter of 12nm. The dry basis content is 71%, of which 67% is boehmite, 5% by weight is gibbsite, and the balance is amorphous alumina.
[0034] P1-2: Dry adhesive powder produced by Changling Catalyst Branch (pore volume 1.2 ml / g, specific surface area 280 m²). 2 / g, with a most accessible pore diameter of 15.8nm. The dry basis is 73%, of which the content of pseudoboehmite is 68%, the content of gibbsite is 5% by weight, and the balance is amorphous alumina.
[0035] P2A: Take P1-1 dry adhesive powder, shape it, dry it at 120℃, grind and sieve it, and select the powder material of 100-400 mesh to obtain the modified P1-1 P2A.
[0036] P2B: Take P1-2 dry adhesive powder, mold it, and then dry it at 120℃. Calcinate the dried molded part at 600℃ for 3 hours, and then grind and sieve the calcined sample. Select the powder material of 100-400 mesh to obtain the modified P1-2 P2B.
[0037] Example 1
[0038] Weigh 950g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of aqueous solution containing 10ml of nitric acid and knead into a plastic mass. Then add 50g of P1-1 powder and mix evenly. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 750℃ for 4 hours in a nitrogen atmosphere, and then calcine them at 750℃ for 4 hours in an air atmosphere to obtain carrier Z1.
[0039] 100g of support Z1 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120°C for 3 hours, it was calcined at 400°C for 3 hours to obtain the hydrogenation demetallization catalyst C1. The composition of C1 is listed in Table 2.
[0040] Example 2
[0041] Weigh 800g of P1-2 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1350ml of an aqueous solution containing 20g of citric acid and 20g of boric acid, and knead to form a plastic mass. Then add 200g of P1-2 powder and mix evenly. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 600℃ for 4 hours in a nitrogen atmosphere, and then calcine them at 600℃ for 4 hours in an air atmosphere to obtain carrier Z2.
[0042] 100 g of support Z2 was weighed and impregnated for 1 hour in 120 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 95.1 g / L MoO3 and 3.8 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrogenation demetallization catalyst C2. The composition of C2 is listed in Table 2.
[0043] Example 3
[0044] Weigh 900g of P1-2 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1350ml of an aqueous solution containing 10g of acetic acid and 20g of boric acid, and knead into a plastic mass. Then add 100g of P2A powder, a modifier of P1, and mix evenly. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 800℃ for 3 hours in a nitrogen atmosphere, and then calcine them at 500℃ for 5 hours in an air atmosphere to obtain carrier Z3.
[0045] 100 g of support Z3 was weighed and impregnated for 1 hour in 120 mL of a mixed solution of molybdenum oxide, basic cobalt carbonate and phosphoric acid containing 59.8 g / L MoO3 and 8.74 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrogenation demetallization catalyst C3. The composition of C3 is listed in Table 2.
[0046] Example 4
[0047] Weigh 750g of P1-2 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1350ml of an aqueous solution containing 20g of oxalic acid and 20g of boric acid, and knead into a plastic mass. Then add 250g of P2B powder, a modifier of P1, and mix evenly. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 650℃ for 5 hours in a nitrogen atmosphere, and then calcine them at 600℃ for 3 hours in an air atmosphere to obtain carrier Z4.
[0048] 100g of support Z4 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120°C for 3 hours, it was calcined at 400°C for 3 hours to obtain the hydrogenation demetallization catalyst C4. The composition of C4 is listed in Table 2.
[0049] Example 5
[0050] Weigh 1000g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of an aqueous solution containing 10ml of nitric acid and knead into a plastic mass. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcinate the dried strips at 750℃ for 4 hours in a nitrogen atmosphere, and then calcine them at 750℃ for 4 hours in an air atmosphere to obtain carrier Z5.
[0051] 100g of support Z5 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120°C for 3 hours, it was calcined at 400°C for 3 hours to obtain the hydrogenation demetallization catalyst C5. The composition of C5 is listed in Table 2.
[0052] Comparative Example 1
[0053] Weigh 1000g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of an aqueous solution containing 10ml of nitric acid and knead to form a plastic mass. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips in air at 750℃ for 4 hours to obtain carrier DZ1.
[0054] 100 g of support DZ1 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrodemetallization catalyst DC1. The composition of DC1 is listed in Table 2.
[0055] Comparative Example 2
[0056] Weigh 1000g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of an aqueous solution containing 10ml of nitric acid and knead into a plastic mass. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips in air at 750℃ for 8 hours to obtain carrier DZ2.
[0057] 100 g of support DZ2 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrogenation demetallization catalyst DC2. The composition of DC2 is listed in Table 2.
[0058] Comparative Example 3
[0059] Weigh 1000g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of an aqueous solution containing 10ml of nitric acid and knead to form a plastic mass. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 750℃ for 4 hours in a nitrogen atmosphere to obtain carrier DZ3.
[0060] 100 g of support DZ3 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrogenation demetallization catalyst DC3. The composition of DC3 is listed in Table 2.
[0061] Comparative Example 4
[0062] Weigh 1000g of P1-1 and mix it evenly with 20g of guar gum powder and 20g of hydroxymethyl cellulose. Then add 1200ml of aqueous solution containing 10ml of nitric acid and knead into a plastic mass. Extrude the mixture into butterfly-shaped strips with an outer diameter of φ1.6mm on a twin-screw extruder. Dry the wet strips at 120℃ for 4 hours to obtain dried strips. Calcine the dried strips at 750℃ for 8 hours in a nitrogen atmosphere to obtain carrier DZ4.
[0063] 100 g of support DZ4 was weighed and impregnated for 1 hour in 110 mL of a mixed solution of molybdenum oxide, basic nickel carbonate and phosphoric acid containing 79.1 g / L MoO3 and 16.2 g / L NiO. After drying at 120 °C for 3 hours, it was calcined at 400 °C for 3 hours to obtain the hydrodemetallization catalyst DC4. The composition of DC4 is listed in Table 2.
[0064] Characterization data show that the alumina support prepared by a combination of anaerobic and aerobic calcination has a pore volume of 0.9-1.6 mL / g and a specific surface area of 100-400 m². 2The carrier, characterized by mercury porosimetry, exhibits a bimodal pore distribution with diameters of 5-20 nm and 100-500 nm. The pore volume of pores with diameters of 5-20 nm accounts for 50-80% of the total pore volume, while the pore volume of pores with diameters of 100-500 nm accounts for 19-40% of the total pore volume. Pores with diameters below 4 nm account for less than 5.5% of the total pore volume, and the pore volume of pores with diameters below 10 nm does not exceed 20% of the total pore volume.
[0065] Table 1
[0066]
[0067] Table 2
[0068]
[0069] Examples 6-10 and Comparative Examples 5-8
[0070] Using atmospheric residue oil (whose properties are listed in Table 3) as feedstock, the catalytic performance of the hydrodemetallization catalysts in the above examples and the comparative agent in the comparative examples was evaluated in a 100 mL small fixed-bed reactor. Each catalyst obtained above was crushed into particles with a diameter of 0.8–1.2 mm, with a catalyst loading of 100 mL. The reaction conditions were: reaction temperature 380 °C, hydrogen partial pressure 14 MPa, and liquid hourly space velocity 0.6 h⁻¹. -1 The hydrogen-to-oil volume ratio was 1000. After 200 hours of reaction, samples were taken, and the nickel and vanadium content in the treated oil was determined using inductively coupled plasma optical emission spectrometry (ICP-AES). (The instrument used was a PE-5300 plasma optical emission spectrometer from PE Corporation, USA; specific methods are detailed in RIPP 124-90 for petrochemical analysis). The evaluation results of each catalyst and contrast agent are shown in Table 4. The demetallization rate, residual carbon removal rate, and desulfurization rate were calculated according to the following formulas:
[0071]
[0072] Table 3
[0073]
[0074] Table 4
[0075] Example catalyst Demetallization rate (%) Desulfurization rate (%) Residual carbon removal rate (%) 6 C1 77 55 30 7 C2 80 58 34 8 C3 71 55 31 9 C4 81 57 33 10 C5 68 51 26 Comparative Example 5 DC1 65 46 24 Comparative Example 6 DC2 67 48 25 Comparative Example 7 DC3 63 47 23 Comparative Example 8 DC4 64 48 24
[0076] According to the results given in Table 4, the hydrodemetallization activity, desulfurization activity and residual carbon removal activity of the hydrodemetallization catalyst provided by the present invention are significantly higher than those of the reference catalyst.
Claims
1. A heavy oil hydrodemetallization catalyst, comprising a support and a metal component supported on the support, wherein, The hydrogenation metal component is selected from one or more Group VIB and Group VIII metals, and its content, calculated as oxides and based on the total weight of the catalyst, is 0.3-20% by weight; the support has a bimodal pore structure with a pore volume of 0.9-1.6 mL / g and a specific surface area of 100-400 m². 2 / g, characterized by mercury porosimetry, the carrier exhibits a bimodal pore distribution with diameters of 5-20nm and 100-500nm, the pore volume of pores with diameters of 5-20nm accounts for 50-80% of the total pore volume, the pore volume of pores with diameters of 100-500nm accounts for 19-40% of the total pore volume, and the pore volume of pores with diameters below 10nm does not exceed 20% of the total pore volume; the carrier is an alumina carrier, and the preparation of the alumina carrier includes the following steps: (1) mixing the raw materials to obtain a plastic body, the raw materials The product includes hydrated alumina P1 containing boehmite, extrusion aid, adhesive solvent and water; (2) the above plastic body is shaped, dried and calcined; characterized in that the calcination includes anaerobic calcination and aerobic calcination, wherein the conditions for anaerobic calcination include: the calcination atmosphere is a gas atmosphere without oxidizing gases, the temperature is 450-1200℃, and the time is 2-10h; and the conditions for aerobic calcination include: the calcination atmosphere is a gas atmosphere containing oxidizing gases, the temperature is 300-900℃, and the time is 2-10h. Before the plastic body is formed in step (2), the step of adding and mixing hydrated alumina P2 containing boehmite is also included. On a dry basis, the mass ratio of P1 to P2 is 70-97:3-30. P2 is a modified product of P1, modified by drying, or P2 is a mixture of the dried product and the calcined product of P1.
2. The catalyst according to claim 1, wherein, The hydrogenation metal component comprises at least one Group VIB metal and at least one Group VIII metal, with the content of the Group VIB metal being 0.5-12% by weight and the content of the Group VIII metal being 0.3-9% by weight, based on the total weight of the catalyst and calculated as oxides.
3. The catalyst according to claim 1, wherein, The group VIB metal is selected from molybdenum and / or tungsten, and the group VIII metal is cobalt and / or nickel; the content of group VIB metal is 5-12 wt% based on oxides and catalyst, and the content of group VIII metal is 0.4-9 wt%.
4. The catalyst according to claim 1, wherein, The P1 pore volume is 0.9~1.4 ml / g, and the specific surface area is 100~450 m. 2 / gram, with a maximum pore diameter of 8~30nm.
5. The catalyst according to claim 1, wherein, The P1 contains 50-95% by weight of boehmite, 2-20% by weight of gibbsite, and the remainder is amorphous alumina.
6. The catalyst according to claim 1, wherein, The raw materials used to prepare the plastic body in step (1) also contain additives, which are one or more of boron-containing compounds, phosphorus-containing compounds and fluorine-containing compounds. The amount of additives added is 0.5-10% of the weight of P1 on a dry basis.
7. The catalyst according to claim 6, wherein, The amount of the additive added is 0.5-5% by weight of P1 on a dry basis.
8. The catalyst according to claim 1, wherein, The drying conditions described in step (2) include: a temperature of 100~250℃ and a time of 2~10 hours.
9. The catalyst according to claim 1, wherein, The gas atmosphere that does not contain oxidizing gases contains one or more of nitrogen and inert gases; the oxidizing gas is a mixture of oxygen and nitrogen, with an oxygen volume content of 5-50%.
10. The catalyst according to claim 1, wherein, The anaerobic roasting conditions include a temperature of 500-900℃ and a time of 2-8h; the aerobic roasting conditions include a temperature of 450-850℃ and a time of 2-8h.
11. The catalyst according to claim 1, wherein, First, perform anaerobic roasting, then perform aerobic roasting.
12. A method for hydrotreating heavy oil, comprising contacting the feedstock oil with a hydrotreating catalyst under hydrotreating conditions, wherein, The hydrogenation catalyst is the heavy oil hydrogenation demetallization catalyst according to any one of claims 1-11.