A hydrodemetallization catalyst and its preparation method and application

Abstract

The application discloses a kind of hydrogen demetallization catalyst and its preparation method and application.The catalyst is spherical particle, including by alumina inner layer, alumina outer layer and the catalyst inner layer of first active component and the carbon film edge layer of second active component supported on the surface of catalyst inner layer, and the thickness of carbon film edge layer is 20 μm-450 μm.The hydrogen demetallization catalyst provided by the application is used in residue hydrogen demetallization reaction, and the utilization rate of active metal and the metal capacity and stability of catalyst are significantly improved.

Description

Technical Field

[0001] The present invention relates to a hydrodemetallization catalyst, in particular to a hydrodemetallization catalyst suitable for heavy oil, especially residual oil hydrotreating process, and a preparation method and application thereof. Background Art

[0002] In recent years, crude oil has become increasingly heavier and inferior in quality, while market demand for lighter oil products continues to rise. This has led to new challenges for hydrogenation technology, a key route for processing heavy oil. As the core of hydrogenation technology, catalyst preparation and performance are crucial for deep hydrogenation of heavy oil. Specifically, the hydrodemetallization reaction is a key chemical reaction occurring during residue hydroprocessing. In the presence of a catalyst, various metal compounds react with H2S to form metal sulfides, which are then deposited on the catalyst for removal. The presence of active metals on the catalyst support plays a crucial role in the catalyst's activity and stability.

[0003] CN102441399A discloses a method for preparing a hydrodemetallization catalyst, comprising preparing a Group VIB metal compound and / or a Group VIII metal compound into an ammonia solution or aqueous solution, which is then impregnated into an alumina support, dried, and calcined to produce the final catalyst. CN1289640A discloses a method for preparing a supported hydrodemetallization catalyst, which utilizes a macroporous alumina support and sprays an ammonia solution or aqueous solution of the active metal onto the support in a spray drum. This method omits the normal temperature drying process of the support after impregnation, and the sprayed support is directly placed in a calcination furnace at a temperature of 300-450°C for calcination, then gradually raised to 460-550°C and maintained at this temperature in air for 1-5 hours. CN103785400A discloses a method for preparing a highly active residue oil hydrodemetallization catalyst, comprising impregnating an alumina carrier with a polyol and / or monosaccharide aqueous solution, hydrothermally carbonizing the carrier in a sealed container, and then loading the carrier with active metal components Mo and Ni. Finally, the alumina loaded with the active components is first calcined under a nitrogen atmosphere and then calcined under an air atmosphere to produce the residue oil hydrodemetallization catalyst. CN111375419A discloses a hydrogenation catalyst and a method for preparing the same, comprising dissolving an iron-containing inorganic salt and ammonium citrate in water to produce a solution; sphericalizing the small-pore alumina and simultaneously adding the solution obtained in the first step to produce alumina; placing the alumina in a ball rolling machine, and uniformly adding the large-pore alumina and the solution obtained in the first step during rolling to produce alumina again; drying the alumina to obtain the final alumina, and then loading the active metal components to produce the catalyst.

[0004] The activity and stability of the hydrodemetallization catalyst prepared by the above method still need to be further improved. Summary of the Invention

[0005] In response to the shortcomings of the prior art, the present invention provides a hydrodemetallization catalyst, a preparation method, and applications thereof. The catalyst, when used in the hydrodemetallization reaction of heavy and residual oils, exhibits strong resistance to carbon deposition, high demetallization activity, high metal tolerance, and high stability.

[0006] The first aspect of the present invention provides a hydrodemetallization catalyst, which is in the form of spherical particles and includes a catalyst inner layer composed of an alumina inner layer, an alumina outer layer and a first active component, and a carbon membrane edge layer loaded with a second active component coated on the surface of the catalyst inner layer, wherein the thickness of the carbon membrane edge layer is 20 μm to 450 μm, preferably 100 μm to 250 μm, and further preferably 100 μm to 120 μm, wherein in the catalyst, the ratio of the content of tetrahedral molybdenum to octahedral molybdenum, calculated as Mo atoms, is 0.16 to 0.33.

[0007] In the present invention, the pore size of the inner aluminum oxide layer is 8 to 18 nm, and the pore size of the outer aluminum oxide layer is 16 to 28 nm; the pore size of the outer aluminum oxide layer is 5 to 15 nm larger than the pore size of the inner aluminum oxide layer.

[0008] In the present invention, the thickness ratio of the inner aluminum oxide layer to the outer aluminum oxide layer in the radial direction is 1 to 5, preferably 2 to 3.

[0009] In the present invention, the pore volume of the carbon membrane edge layer is between 0.80 and 1.60 cm 3 / g, preferably 0.9 to 1.5 cm 3 / g. The average pore size is between 35 and 90 nm, preferably between 50 and 75 nm. The carbon membrane edge layer can retain some carbon deposits while allowing macromolecular reactants to diffuse effectively.

[0010] In the present invention, the first active metal component includes molybdenum and a Group VIII metal, and the second active metal component includes molybdenum and a Group VIII metal; the Group VIII metal in the first active metal component is preferably nickel, and the Group VIII metal in the second active metal component is preferably nickel.

[0011] In the present invention, based on the mass of the catalyst, the content of MoO3 is 8.0% to 20.0%, and the content of the Group VIII metal oxide is 2.0% to 12.0%.

[0012] In the present invention, in the catalyst, the ratio of the mass of the first active component calculated as the total loading of MoO3 and the Group VIII metal oxide to the mass of the second active component calculated as the total loading of MoO3 and the Group VIII metal oxide is 1.76-2.35.

[0013] In the present invention, the specific surface area of ​​the catalyst is 150 to 190 m 2 / g, and a pore volume of 0.50-1.00 mL / g; preferably, the specific surface area of ​​the catalyst is 160-175 m 2 / g, and the pore volume is 0.77~0.90mL / g.

[0014] In the present invention, the catalyst further comprises an auxiliary component, which is selected from at least one of fluorine, phosphorus, silicon or boron, preferably phosphorus. The content of the auxiliary component as oxide is 1.0% to 6.0% based on the mass of the catalyst.

[0015] The second aspect of the present invention provides a method for preparing the above-mentioned hydrodemetallization catalyst, comprising the following steps:

[0016] (1) neutralizing an acidic aluminum salt solution with an alkaline aluminum salt solution and subjecting the solution to primary aging to obtain a slurry;

[0017] (2) the slurry obtained in step (1) is divided equally into slurry I and slurry II, a water-soluble polymer J1 is added to slurry II, slurry I and slurry II are subjected to secondary aging and drying, respectively, to obtain dried products I and dried products II;

[0018] (3) preparing the dried product II obtained in step (2) into a pseudo-boehmite mixed solution II and adjusting its pH value, sealing the solution, and obtaining a mixed solution III;

[0019] (4) adding the dried product I obtained in step (2) and the mixed solution III obtained in step (3) to a rolling ball machine at a certain rate, and simultaneously spraying the first impregnation solution containing the first active component at a uniform rate to obtain an inner layer of alumina loaded with the first active component;

[0020] (5) adjusting the relative dripping rate of the mixed solution III, continuing to spray the mixed solution containing the first active metal component at a uniform rate, drying, and calcining to obtain the inner layer of the hydrodemetallization catalyst;

[0021] (6) soaking the inner layer of the catalyst obtained in step (5) in a carbohydrate aqueous solution, drying, and then carbonizing to obtain a catalyst intermediate;

[0022] (7) The catalyst intermediate obtained in step (6) is impregnated with a second impregnation solution containing a second active component in a saturated impregnation manner, and then dried and calcined to obtain the hydrodemetallization catalyst.

[0023] In step (1) of the present application, the acidic aluminum salt solution and the basic aluminum salt solution are added to the reactor in a parallel flow mode.

[0024] In step (1), the acidic aluminum salt solution is one or more of aluminum sulfate solution, aluminum nitrate solution or aluminum chloride solution; the concentration of the acidic aluminum salt solution, calculated as Al2O3, is 5 g / 100 mL to 30 g / 100 mL. The basic aluminum salt solution is one or both of sodium aluminate solution or potassium aluminate solution; the concentration of the basic aluminum salt solution, calculated as Al2O3, is 8 g / 100 mL to 58 g / 100 mL.

[0025] In step (1), the temperature of the neutralization reaction is 80 to 130°C, and the time is 30 to 150 min, and the pH value of the slurry is controlled to be 6.0 to 9.5 during the neutralization reaction. The pH value of the slurry is adjusted by controlling the addition rate of the acidic aluminum salt solution and the basic aluminum salt solution or by additionally adding an acid-base regulator during the neutralization reaction.

[0026] In step (1), the temperature of the first aging is 100 to 230°C, the time is 60 to 220 min, and the pH value is 9.0 to 12.0.

[0027] In step (1), after the first aging, the slurry is preferably concentrated first, and then the second aging is performed. After the concentration, the volume of the slurry is 40% to 70% of the original volume.

[0028] In step (2), the water-soluble high polymer J1 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose, and is preferably polyethylene glycol; the viscosity of the water-soluble high polymer J1 (20°C) is 10 to 1000 mPa·s, and the viscosity of the slurry after the addition of the water-soluble high polymer J1 (20°C) is 150 to 650 mPa·s.

[0029] In step (2), the temperature of the second aging is 120 to 260°C, the time is 40 to 200 min, and the temperature of the second aging is 30 to 60°C higher than the temperature of the first aging.

[0030] In step (2), the drying temperature after the second aging is 120 to 180°C, and the drying time is 2 to 10 h, and before the drying, the filtration and washing can be performed according to the conventional known method. The dry basis content of the dry product I and the dry product II after the drying is 40 wt% to 70 wt%.

[0031] In step (3), the solid content of the obtained mixture III is 15% to 40% by mass, the pH value is 6.0 to 8.0, the adjustment mode is solvent adjustment, the solvent can be one or more of phosphoric acid, nitric acid, oxalic acid, citric acid, and tartaric acid, and the sealing treatment time is 6 to 10 hours.

[0032] In step (4), the rotating speed of the rolling ball machine is 30 to 50 r / min. After the first balling is completed, the obtained small balls have a diameter of 0.4 to 0.8 mm.

[0033] In step (4), the ratio of the addition rate of the dry substance I to the mixture III is 0.60 to 0.95 g / ml, and the ratio of the dropping rate of the first impregnation solution to the dry substance I is 0.11 to 0.42 ml / g. The dropping time is based on the balling time.

[0034] In step (4), the amount of the first impregnation solution accounts for 15% to 45% of the saturated water absorption amount of the dry substance I. The first impregnation solution is an impregnation solution containing Mo and Group VIII metal (preferably Ni), wherein the active metal component Mo is derived from one or both of molybdenum oxide and ammonium heptamolybdate, and the nickel is derived from one or both of basic nickel carbonate and nickel nitrate. The content of MoO3 and Group VIII metal oxide in the first impregnation solution is 30.0 to 60.0 g / 100 ml and 5.0 to 30.0 g / 100 ml, respectively.

[0035] In step (4), the first impregnation solution can further introduce at least one additive containing fluorine, phosphorus, silicon, or boron. The additive (calculated as oxide) is added in an amount of 15% to 30% of the total mass of molybdenum oxide in the first impregnation solution, preferably 18% to 26%.

[0036] In step (4), preferably, the first impregnation solution further contains a water-soluble high polymer J2. The water-soluble high polymer J2 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide, and methyl cellulose. The viscosity of the water-soluble high polymer J2 is 10 to 1000 m Pa·s, and the viscosity of the slurry after adding the water-soluble high polymer J2 is 150 to 650 m Pa·s.

[0037] In step (5), the ratio of the addition rate of the dry substance I to the mixture III is 0.40 to 0.58 g / ml, and the ratio of the dropping rate of the first impregnation solution to the dry substance I is 0.11 to 0.42 ml / g.

[0038] In step (5), in the inner layer of the catalyst, the amount of MoO3 introduced into the catalyst from the first impregnation solution accounts for 55% to 70% of the total MoO3 loading in the catalyst; and the amount of Group VIII metal oxide introduced into the catalyst from the first impregnation solution accounts for 55% to 70% of the total Group VIII metal oxide loading in the catalyst.

[0039] In step (5), the drying temperature is 120-200°C, and the drying time is 2-12 h.

[0040] In step (5), the calcination is performed by programmed temperature increase. The temperature increase rate is 1-3°C / min, the calcination temperature is 550-750°C, the calcination time is 3-8 h, and the calcination atmosphere is one or more of nitrogen, water vapor or air, preferably air.

[0041] In step (6), the carbohydrate solution is preferably an aqueous solution of starch and / or monosaccharide, and the mass concentration of the starch and / or monosaccharide in the solution is 20.0%-40.0%. The monosaccharide includes one or more of glucose, ribose, fructose and maltose.

[0042] In step (6), ammonium bicarbonate is added to the carbohydrate solution as a pore-expanding agent, and the mass concentration of the ammonium bicarbonate in the carbohydrate solution is 15.0%-35.0%. The soaking time is 0.5-10 min, preferably 3.0-6.0 min.

[0043] In step (6), the carbonization conditions are as follows: pre-oxidation at 160-320°C, preferably 240-320°C, for 4-20 h, preferably 3-16 h, in an air atmosphere; and carbonization at 400-700°C, preferably 450-650°C, for 2-10 h, in a nitrogen atmosphere. After carbonization, the edge layer is formed on the surface of the catalyst.

[0044] In step (7), the active metal in the second active metal impregnation solution is preferably molybdenum and nickel. The content of MoO3 in the second active metal impregnation solution is 2.0-16.0 g / 100 ml, and the content of NiO is 1.0-8.0 g / 100 ml.

[0045] In step (7), the second impregnation solution is an impregnation solution containing Mo and a Group VIII metal (preferably Ni), wherein the active metal component molybdenum is derived from one or both of molybdenum trioxide and ammonium heptamolybdate, and the nickel is derived from one or both of basic nickel carbonate and nickel nitrate. The amount of MoO3 introduced into the catalyst from the second impregnation solution is 30%-45% of the total MoO3 loading in the catalyst, and the amount of Group VIII metal oxide introduced into the catalyst from the second impregnation solution is 30%-45% of the total Group VIII metal oxide loading in the catalyst.

[0046] In step (7), the second impregnation solution preferably further contains a water-soluble polymer J3. The water-soluble polymer J3 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose. The viscosity of the water-soluble polymer J3 is 10-1000 mPa·s at 20℃, and the viscosity of the slurry after adding the water-soluble polymer J3 is 150-650 mPa·s at 20℃.

[0047] In step (7), the impregnation method is saturation impregnation, the drying temperature is 120-200℃, and the drying time is 2-12h. The calcination method is programmed temperature rising, the temperature rising rate is 1℃ / min-3℃ / min, the calcination temperature is 400-550℃, and the calcination time is 3-6h.

[0048] The third aspect of the present application provides application of the above-mentioned hydrodemetallization catalyst in a residue hydroprocessing process.

[0049] Compared with the prior art, the present application has the following beneficial effects:

[0050] For the hydrogen demetallization catalyst, the unobstructed pore structure and the reasonable active metal distribution are most important for the performance of the catalyst. For the active metal, the reduction temperature of the tetrahedral Mo species is higher than that of the octahedral Mo species, and the existence of the tetrahedral Mo species has an adverse effect on weakening the interaction between the support and the metal, thereby affecting the catalyst activity and stability. The inventors have found through a large number of studies that, firstly, the preparation of the support is optimized, the slurry obtained after the neutralization reaction is subjected to two-stage aging, the slurry is subjected to treatment processes with and without the addition of water-soluble polymer before the second aging, and the second aging is performed at a higher temperature, so that a porous material with a suitable specific surface area and different pore size distributions, i.e., dry material I and dry material II, can be obtained; the dry material II is prepared into pseudo-boehmite mixed solution II, the pH is adjusted and the mixed solution III is obtained after sealed treatment for a period of time, and the dry material I and the mixed solution III are formed into a ball at a certain addition rate; in the ball forming process, the first impregnation solution is sprayed into the ball at a uniform drop rate. After the ball crystal grains grow to a certain size, the relative addition rate of the dry material I and the mixed solution III is adjusted, the first impregnation solution is continuously sprayed at a constant rate, and then the catalyst is dried, calcined, coated with a carbon film on the surface of the inner layer through special treatment, and then impregnated with a second active metal component in a saturated manner to form a carbon film edge layer containing part of the active metal on the surface of the inner layer, so that the hydrogen demetallization catalyst is prepared. Through the above treatment process, not only the relative content of the tetrahedral Mo and the octahedral Mo in the final catalyst is effectively controlled, but also the pore structure of the pre-support gradually unobstructed from the inside to the outside is prepared by adjusting the addition rate of the solid and the liquid in the ball forming process; the active metal is introduced in stages during the preparation of the catalyst, so that the active metal is dispersed in the inner layer in a large range; the edge layer formed by coating the carbon film on the surface of the inner layer of the catalyst not only avoids the coking, sulfide and iron, calcium and other deposits produced by the intense reaction of the residual oil macromolecules on the active sites of the catalyst surface from blocking the pore channels of the catalyst and covering the active sites, but also improves the utilization rate of the active metal and the metal capacity and stability of the catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 Raman spectrum of the surface of the catalyst obtained in Example 1;

[0052] Figure 2 Raman spectrum of the surface of the catalyst obtained in Example 2;

[0053] Figure 3 Raman spectrum of the surface of the catalyst obtained in Comparative Example 1;

[0054] Figure 4 Raman spectrum of the surface of the catalyst obtained in Comparative Example 2. DETAILED DESCRIPTION

[0055] In the present application, the Raman spectrum of the catalyst is characterized by using the DXR Microscope type DXR Microscope Raman spectrometer of Thermo Scientific Company. Among them, the peak near 930cm- 1 The peak near 960cm- 1 The peak near 960cm-

[0056] In the present application, the pore structure (SVD) and specific surface area of the catalyst are characterized by using the ASAP-2420 physical adsorption instrument of Micromeritics Company. The pore volume and pore size of the carbon film edge layer are obtained by using the mercury injection method.

[0057] The technical solutions and effects of the present application will be further illustrated by the following examples, but are not limited to the following examples.

[0058] Example 1

[0059] The 1.5L aluminum sulfate aqueous solution (the concentration of Al2O3 is 10.0g / 100mL, and the initial temperature is 75℃) is introduced into the reaction kettle from the upper part, which is equipped with a 5L pure water stirring device and a heating jacket. The 1L sodium aluminate aqueous solution (the concentration of Al2O3 is 28.0g / 100mL, and the initial temperature is 110℃) is introduced into the reaction kettle from the bottom of the kettle. The neutralization reaction temperature is controlled at 105℃. The aluminum sulfate solution and the sodium aluminate solution are continuously added, and the pH value is controlled at 8.5. The reaction is carried out for 60min. After the concurrent flow is completed, a first aging is carried out. The aging temperature is 150℃, the aging time is 120min, and the aging pH value is 9.3. After the first aging is completed, the slurry volume is concentrated to 5L, and then evenly divided into two parts, which are slurry I and slurry II. 25g of polyvinyl alcohol (viscosity is 30mPa·s) is added to the slurry II. The slurry viscosity (20℃) after adding the polyvinyl alcohol is 260mPa·s. The slurry I is not treated. Then the slurry I and the slurry II are both heated to 180℃, and a second aging is carried out. The aging time is 120min. The washing and drying are carried out, and the dry base of 50wt% of dry material I and dry material II are obtained.

[0060] The dry material II was mixed with deionized water to a solid content of 16.7% to obtain a mixture II, and the pH value of which was adjusted to 6.5, and the mixture was sealed and treated for 6 h to obtain a mixture III. 800 g of the dry material I and 960 ml of the mixture III were added to the rolling ball machine at an addition rate of 13.3 g / min and 16.0 ml / min, respectively, while the first impregnation solution was sprayed into the rolling ball machine at a dropping rate of 2.0 ml / min. The first impregnation solution contained MoO3 at a content of 39.6 g / 100 ml, NiO at a content of 6.6 g / 100 ml, and the additive phosphoric acid (P in the form of an oxide) was added at an amount of 23.7% of the total mass of MoO3 in the impregnation solution (the amount of the first impregnation solution was 22% of the saturated water absorption of the dry material I), and polyacrylamide (viscosity of 950 mPa-s) was added to the first impregnation solution, and the viscosity of the first impregnation solution after the addition was 600 mPa-s. The addition rate of the dry material I was kept unchanged, and the dropping rate of the mixture III was changed to 24.0 ml / min, and the first impregnation solution was continuously sprayed into the rolling ball machine at a rate of 2.0 ml / min, and the obtained sample was dried at 120 °C for 6 h and calcined at 750 °C for 3 h to prepare the inner layer of the hydrogen demetallization catalyst. The amount of MoO3 introduced into the catalyst from the first impregnation solution was 64% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst from the first impregnation solution was 64% of the total NiO loading in the catalyst, and the spraying time was controlled to be within 60 min.

[0061] The inner layer of the catalyst was taken out after being soaked in an aqueous solution containing ammonium bicarbonate at a mass percentage of 32.0% and starch at a mass percentage of 38.0% for 240 s, and was subjected to pre-oxidation at 310 °C for 10 h in an air atmosphere, and was then carbonized at 500 °C for 5 h in a nitrogen atmosphere. Then, the second active metal component was loaded on the catalyst intermediate by saturated impregnation, and polyacrylamide (viscosity of 950 mPa-s) was added to the second impregnation solution, and the viscosity of the second impregnation solution after the addition was 400 mPa-s. The amount of MoO3 introduced into the catalyst from the second impregnation solution was 36% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst from the second impregnation solution was 36% of the total NiO loading in the catalyst, and the spraying time was controlled to be within 60 min, and then the catalyst was dried at 120 °C for 6 h and calcined at 450 °C for 5 h, wherein the temperature increasing rate during the calcination process was 3 °C / min.

[0062] The hydrogen demetallization catalyst CAT-1 was prepared. The ratio of tetrahedral molybdenum to octahedral molybdenum was 0.17. The thickness of the carbon film edge layer was 118 μm, the pore volume was 1.25 cm3 / g, and the average pore diameter was 74 nm. The other physicochemical properties of the catalyst are shown in Table 1. 3 / g, average pore diameter was 74 nm. The other physicochemical properties of the catalyst are shown in Table 1.

[0063] Example 2

[0064] Same as Example 1, except that the initial temperature of the sodium metaaluminate aqueous solution added was 100°C, 50 g of polyvinyl alcohol (viscosity 30 mPa·s) was added to slurry II after the first aging, and the slurry viscosity (20°C) after the addition of polyvinyl alcohol was 280 mPa·s;

[0065] The dried material II was mixed with deionized water to a solid content of 18.2% to obtain a mixed solution II. The pH of the solution was adjusted to 7.0 and the solution was sealed for 7 hours to obtain a mixed solution III. 800 g of the dried material I and 1040 ml of the mixed solution III were added to a rolling ball machine at addition rates of 13.3 g / min and 17.3 ml / min, respectively. Simultaneously, the first impregnation solution (same as in Example 1) was sprayed into the solution at a drop rate of 2.0 ml / min. The first impregnation solution contained 40.9 g / 100 ml of MoO3 and 6.8 g / 100 ml of NiO. The amount of phosphoric acid (calculated as oxide) added was 23.7% of the total mass of molybdenum oxide in the impregnation solution (the amount of the first impregnation solution used was 22% of the saturated water absorption capacity of the dried material I). Polyacrylamide (viscosity of 950 mPa·s) was added to the first impregnation solution, achieving a viscosity of 600 mPa·s after addition. The spraying time was controlled within 60 minutes. In the inner layer of the catalyst, the amount of MoO3 introduced into the catalyst by the first impregnation liquid is 66% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst by the first impregnation liquid is 66% of the total NiO loading in the catalyst.

[0066] The addition rate of the adjusted dried material I was maintained constant, and the addition rate of the mixed solution III was adjusted to 26.0 ml / min. The first impregnation solution (same as in Example 1) was continuously sprayed at a rate of 2.0 ml / min. During the calcination process, the temperature was raised to 700°C at a rate of 3°C / min for 4 hours. The inner layer of the catalyst was immersed in an aqueous solution containing 22.0% by mass of ammonium bicarbonate and 30.0% by mass of starch for 220 seconds, then removed and pre-oxidized at 290°C in an air atmosphere for 8 hours, followed by carbonization at 550°C in a nitrogen atmosphere for 6 hours.

[0067] The hydrodemetallization catalyst CAT-2 was prepared. The ratio of tetrahedral molybdenum to octahedral molybdenum was 0.20. The thickness of the carbon membrane edge layer was 113 μm and the pore volume was 1.22 cm 3 / g, and the average pore size is 67nm. Other physical and chemical properties of the catalyst are shown in Table 1.

[0068] Example 3

[0069] The same as Example 1, except that the dried material II was mixed with deionized water at a solid content of 20.0% to obtain mixed solution II, and the pH value was adjusted to 7.5. The mixture was sealed for 8 hours to obtain mixed solution III. During the ball forming process, 800 g of the dried material I and 1120 ml of mixed solution III were added to the ball rolling machine at addition rates of 13.3 g / min and 18.7 ml / min, respectively. At the same time, the first impregnation solution (same as Example 1) was sprayed therein at a dropwise acceleration rate of 2.0 ml / min. The content of MoO3 in the first impregnation solution is 42.1g / 100ml, the content of NiO is 7.0g / 100ml, the amount of P (calculated as oxide) added in the auxiliary phosphoric acid is 23.7% of the total mass of molybdenum oxide in the impregnation solution (the amount of the first impregnation solution is 22% of the saturated water absorption capacity of the dry substance I), and polyacrylamide (viscosity of 950mPa·s) is added to the first impregnation solution. After addition, the viscosity is 600mPa·s, and the spraying time is controlled within 60min. The droplet rate of mixed solution III was adjusted to 28.0 ml / min, and the first impregnation solution (same as in Example 1) was continuously sprayed therein at a rate of 2.0 ml / min. During the roasting process, the temperature was raised to 650° C. at a heating rate of 3° C. / min for 5 h to obtain an inner layer of the catalyst, wherein the amount of MoO3 introduced into the catalyst by the first impregnation solution was 68% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst by the first impregnation solution was 68% of the total NiO loading in the catalyst. The inner layer of the catalyst was immersed in an aqueous solution containing 18.0% by mass of ammonium bicarbonate and 26.0% by mass of glucose for 200 s, then removed and pre-oxidized at 270° C. in an air atmosphere for 6 h, and then carbonized at 600° C. in a nitrogen atmosphere for 7 h.

[0070] The hydrodemetallization catalyst CAT-3 was prepared. The ratio of tetrahedral molybdenum to octahedral molybdenum was 0.25. The thickness of the carbon membrane edge layer was 107 μm and the pore volume was 1.22 cm 3 / g, and an average pore size of 65nm. Other physical and chemical properties of the catalyst are shown in Table 1.

[0071] Example 4

[0072] The same method as in Example 1 was used, except that the dried product II was mixed with deionized water at a solid content of 22.2% to obtain a mixed solution II, and its pH was adjusted to 8.0. The mixture was sealed for 9 hours to obtain a mixed solution III. During the ball forming process, 800 g of the dried product I and 1200 ml of the mixed solution II were added to the ball rolling machine at addition rates of 13.3 g / min and 20.0 ml / min, respectively. Simultaneously, the first impregnation solution (same as in Example 1) was sprayed therein at a dropwise acceleration rate of 2.0 ml / min. The content of MoO3 in the first impregnation solution is 43.3g / 100ml, the content of NiO is 7.2g / 100ml, the amount of P (calculated as oxide) added in the auxiliary phosphoric acid is 23.7% of the total mass of molybdenum oxide in the impregnation solution (the amount of the first impregnation solution is 22% of the saturated water absorption capacity of the dry substance I), and polyacrylamide (viscosity of 950mPa·s) is added to the first impregnation solution. After addition, the viscosity is 600mPa·s, and the spraying time is controlled within 60min. The droplet rate of the mixed solution III was adjusted to 30.0 ml / min, and the first impregnation solution (same as in Example 1) was continuously sprayed therein at a rate of 2.0 ml / min. During the roasting process, the temperature was raised to 600° C. at a rate of 3° C. / min and roasted for 6 h to obtain an inner layer of the catalyst, wherein the amount of MoO3 introduced into the catalyst by the first impregnation solution was 70% of the total MoO3 loading in the catalyst; the amount of NiO introduced into the catalyst by the first impregnation solution was 70% of the total NiO loading in the catalyst. The inner layer of the catalyst was soaked in an aqueous solution containing 16.0% by mass of ammonium bicarbonate and 24.0% by mass of glucose for 180 seconds, then removed and pre-oxidized at 250° C. in an air atmosphere for 4 h, and then carbonized at 650° C. in a nitrogen atmosphere for 8 h.

[0073] The hydrodemetallization catalyst CAT-4 was prepared. The ratio of tetrahedral molybdenum to octahedral molybdenum was 0.32. The thickness of the carbon membrane edge layer was 103 μm, and the pore volume was 1.13 cm 3 / g, and an average pore size of 55nm. Other physical and chemical properties of the catalyst are shown in Table 1.

[0074] Comparative Example 1

[0075] The same as Example 1, except that the slurry obtained after the first aging was directly heated and then aged a second time to obtain dried product I; dried product II was replaced with an equal amount of dried product I for subsequent pelletizing; and the hydrodemetallization catalyst dCAT-1 was prepared.

[0076] The ratio of tetrahedral molybdenum to octahedral molybdenum in catalyst dCAT-1 is 1.04. The thickness of the carbon membrane edge layer is 80 μm and the pore volume is 1.06 cm 3 / g, and an average pore diameter of 53nm. Other physical and chemical properties of the catalyst are shown in Table 1.

[0077] Comparative Example 2

[0078] The same as Example 1 except that during the balling process, the first and second impregnation solutions were not added, but after the balling was completed, the active metal loading process was carried out by saturated impregnation. The hydrodemetallization catalyst dCAT-2 was prepared.

[0079] The ratio of tetrahedral molybdenum to octahedral molybdenum in catalyst dCAT-2 was 2.15. The thickness of the carbon film edge layer was 76 μm, the pore volume was 1.08 cm 3 / g, and the average pore diameter was 55 nm. The other physicochemical properties of this catalyst are shown in Table 1.

[0080] Comparative Example 3

[0081] The same as Example 1 except that during the entire balling process, the dry material I and the mixed solution III were added to the balling machine at a rate of 13.3 g / min and 16.0 ml / min, respectively; and all of the calcination processes were carried out by increasing the temperature to 550°C at a rate of 3°C / min, and the calcination time was 3 h. The hydrodemetallization catalyst dCAT-4 was prepared.

[0082] The ratio of tetrahedral molybdenum to octahedral molybdenum in catalyst dCAT-3 was 3.16. The thickness of the carbon film edge layer was 78 μm, the pore volume was 1.01 cm 3 / g, and the average pore diameter was 49 nm. The other physicochemical properties of this catalyst are shown in Table 1.

[0083] Comparative Example 4

[0084] The same as Example 1 except that the content of the first active component on the inner layer of the catalyst was 45% of the total active component loading on the catalyst, and the content of the second active component on the carbon film edge layer was 55% of the total active component loading on the catalyst; and all of the calcination processes were carried out by increasing the temperature to 600°C at a rate of 2°C / min, and the calcination time was 3 h. The hydrodemetallization catalyst dCAT-4 was prepared.

[0085] The ratio of tetrahedral molybdenum to octahedral molybdenum in catalyst dCAT-4 was 1.37. The thickness of the carbon film edge layer was 116 μm, the pore volume was 1.18 cm 3 / g, and the average pore diameter was 67 nm. The other physicochemical properties of this catalyst are shown in Table 1.

[0086] Table 1 Physicochemical properties of the hydrodemetallization catalysts of the various examples

[0087]

[0088] Evaluation test

[0089] The activity stability tests were carried out on the hydrogenation catalysts of examples 1-4 and comparative examples 1-4 in a 200ml fixed bed hydrogenation test device, and the raw oil was a certain residual oil raw material, the S content was 2.96wt%, the contents of metals Ni and V were 36.7μg / g and 64.2μg / g respectively, and the CCR content was 12.6wt%. The reaction conditions were as follows: the reaction temperature was 390℃, the reaction pressure was 15.0Mpa, the liquid hourly space velocity was 1.0h -1 , the volume hydrogen oil ratio was 800, and the demetallization rate of example 1 after running for 100h was 100%, and the others were relative demetallization rates. The test results are shown in table 2.

[0090] Table 2 Test results of hydrogenation demetallization catalysts

[0091]

[0092] As can be seen from table 1 and table 2, the hydrogenation demetallization catalyst prepared by the method of the present application has a higher specific surface area and pore volume, and has higher reaction activity and stability, and can well meet the hydrogenation demetallization process of heavy oil, especially residual oil.

Claims

1. A hydrodemetallization catalyst, comprising spherical particles comprising an inner catalyst layer consisting of an inner alumina layer, an outer alumina layer, and a first active component, and a carbon membrane edge layer coated on the surface of the inner catalyst layer and loaded with a second active component, wherein the carbon membrane edge layer has a thickness of 100 μm to 250 μm, wherein the ratio of tetrahedral molybdenum to octahedral molybdenum in the catalyst, calculated as Mo atoms, is 0.16 to 0.33; The first active component includes molybdenum and a Group VIII metal, and the second active component includes molybdenum and a Group VIII metal; in the catalyst, the ratio of the mass of the first active component, calculated as the total loading of MoO3 and the Group VIII metal oxide, to the mass of the second active component, calculated as the total loading of MoO3 and the Group VIII metal oxide, is 1.76 to 2.35; The pore size of the inner aluminum oxide layer is 8 to 18 nm, the pore size of the outer aluminum oxide layer is 16 to 28 nm, and the pore size of the outer aluminum oxide layer is 5 to 15 nm larger than the pore size of the inner aluminum oxide layer; The preparation method of the catalyst comprises the following steps: (1) Acidic aluminum salt solution and alkaline aluminum salt solution are subjected to neutralization reaction and primary aging to obtain a slurry; (2) The slurry obtained in step (1) is evenly divided into slurry I and slurry II, a water-soluble polymer J1 is added to slurry II, and slurry I and slurry II are subjected to secondary aging and drying, respectively, to obtain dried products I and dried products II; (3) preparing the dried product II obtained in step (2) into a pseudo-boehmite mixed solution II and adjusting its pH value, sealing the solution, and obtaining a mixed solution III; (4) adding the dried product I obtained in step (2) and the mixed solution III obtained in step (3) to a rolling ball machine at a certain rate, and simultaneously spraying the first impregnation solution containing the first active component at a uniform rate to obtain an inner layer of alumina loaded with the first active component; (5) adjusting the relative dripping rate of the mixed solution III, continuing to spray the mixed solution containing the first active metal component at a uniform speed, drying, and calcining to obtain the inner layer of the hydrodemetallization catalyst; (6) soaking the inner layer of the catalyst obtained in step (5) in a carbohydrate aqueous solution, drying, and then carbonizing to obtain a catalyst intermediate; (7) impregnating the catalyst intermediate obtained in step (6) with a second impregnation solution containing a second active component in a saturated impregnation manner, and then drying and calcining the impregnation solution to obtain the hydrodemetallization catalyst; In step (1), the temperature of the primary aging is 100-230°C, and in step (2), the temperature of the secondary aging is 120-260°C, and the temperature of the secondary aging is 30-60°C higher than the temperature of the primary aging; In step (4), the ratio of the addition rate of the dried product I to the mixed solution III is 0.60-0.95 g / mL, and the ratio of the dropwise addition rate of the first impregnation solution to the dried product I is 0.11-0.42 mL / g; In step (5), the ratio of the addition rate of the dried product I to the mixed solution III is 0.40-0.58 g / mL, and the ratio of the dropwise addition rate of the first impregnation solution to the dried product I is 0.11-0.42 mL / g; In step (5), the calcination temperature is 550-750°C; in step (7), the calcination temperature is 400-550°C.

2. The catalyst according to claim 1, characterized in that In the catalyst, the carbon film edge layer has a thickness of 100 μm to 120 μm.

3. The catalyst according to claim 1, characterized in that The thickness ratio of the inner aluminum oxide layer to the outer aluminum oxide layer in the radial direction is 1-5.

4. The catalyst according to claim 1, characterized in that The thickness ratio of the inner aluminum oxide layer to the outer aluminum oxide layer in the radial direction is 2 to 3.

5. The catalyst according to claim 1, characterized in that The pore volume of the carbon membrane edge layer is 0.80~1.60cm 3 / g, and the average pore size is 35~90nm.

6. The catalyst according to claim 1, characterized in that The pore volume of the carbon membrane edge layer is 0.9~1.5cm 3 / g, and the average pore size is 50~75nm.

7. The catalyst according to claim 1, characterized in that In the catalyst, based on the mass of the catalyst, the content of MoO3 is 8.0% to 20.0%, and the content of the Group VIII metal oxide is 2.0% to 12.0%.

8. The catalyst according to claim 1, characterized in that The specific surface area of ​​the catalyst is 150~190m 2 / g, and the pore volume is 0.50~1.00mL / g.

9. The catalyst according to claim 1, characterized in that The specific surface area of ​​the catalyst is 160~175m 2 / g, and the pore volume is 0.77~0.90mL / g.

10. The catalyst according to claim 1, characterized in that The catalyst includes an auxiliary component, which is selected from at least one of fluorine, phosphorus, silicon or boron; based on the mass of the catalyst, the content of the auxiliary component in terms of oxide is 1.0% to 6.0%.

11. The catalyst according to claim 10, characterized in that The auxiliary component is phosphorus.

12. A method for preparing the catalyst according to any one of claims 1 to 9, comprising the steps of: (1) Acidic aluminum salt solution and alkaline aluminum salt solution are subjected to neutralization reaction and primary aging to obtain a slurry; (2) The slurry obtained in step (1) is evenly divided into slurry I and slurry II, a water-soluble polymer J1 is added to slurry II, and slurry I and slurry II are subjected to secondary aging and drying, respectively, to obtain dried products I and dried products II; (3) preparing the dried product II obtained in step (2) into a pseudo-boehmite mixed solution II and adjusting its pH value, sealing the solution, and obtaining a mixed solution III; (4) adding the dried product I obtained in step (2) and the mixed solution III obtained in step (3) to a rolling ball machine at a certain rate, and simultaneously spraying the first impregnation solution containing the first active component at a uniform rate to obtain an inner layer of alumina loaded with the first active component; (5) adjusting the relative dripping rate of the mixed solution III, continuing to spray the mixed solution containing the first active metal component at a uniform speed, drying, and calcining to obtain the inner layer of the hydrodemetallization catalyst; (6) soaking the inner layer of the catalyst obtained in step (5) in a carbohydrate aqueous solution, drying, and then carbonizing to obtain a catalyst intermediate; (7) The catalyst intermediate obtained in step (6) is impregnated with a second impregnation solution containing a second active component in a saturated impregnation manner, and then dried and calcined to obtain the hydrodemetallization catalyst.

13. The preparation method according to claim 12, characterized in that In step (1), the acidic aluminum salt solution and the alkaline aluminum salt solution are subjected to a parallel neutralization reaction; the acidic aluminum salt solution is one or more of aluminum sulfate solution, aluminum nitrate solution or aluminum chloride solution; the concentration of the acidic aluminum salt solution in terms of Al2O3 is 5g / 100mL~30g / 100mL; the alkaline aluminum salt solution is one or both of sodium metaaluminate solution and potassium metaaluminate solution; the concentration of the alkaline aluminum salt solution in terms of Al2O3 is 8g / 100mL~58g / 100mL.

14. The preparation method according to claim 12, characterized in that In step (1), the neutralization reaction temperature is 80-130° C., the time is 30-150 min, and the pH value of the slurry is controlled to be 6.0-9.5 during the neutralization reaction.

15. The preparation method according to claim 12, characterized in that In step (1), the temperature of the primary aging is 100-230°C, the time is 60-220 min, and the pH value is 9.0-12.0; in step (2), the temperature of the secondary aging is 120-260°C, the time is 40-200 min, and the temperature of the secondary aging is 30-60°C higher than the temperature of the primary aging.

16. The preparation method according to claim 12, characterized in that In step (2), the water-soluble polymer J1 is one or more of polyethylene glycol, polyvinyl alcohol, polyacrylamide and methyl cellulose; the viscosity of the water-soluble polymer J1 at 20°C is 10~1000 mPa·s, and the viscosity of the slurry at 20°C after adding the water-soluble polymer J1 is 150~650 mPa·s.

17. The preparation method according to claim 12, characterized in that In step (2), the water-soluble polymer J1 is polyethylene glycol.

18. The preparation method according to claim 12, characterized in that: In step (2), the drying temperature after secondary aging is 120-180° C., the drying time is 2-10 h, and the dry basis contents of the dried products I and II obtained after drying are both 40 wt %-70 wt %.

19. The preparation method according to claim 12, characterized in that: In step (3), the solid content of the obtained mixed solution III is 15% to 40%, the pH value ranges from 6.0 to 8.0, and the sealing treatment time is 6 to 10 hours.

20. The preparation method according to claim 12, characterized in that In step (4), the ratio of the addition rate of the dried material I to the mixed solution III is 0.60-0.95 g / mL, and the ratio of the droplet rate of the first impregnation liquid to the dried material I is 0.11-0.42 mL / g; and / or, in step (5), the ratio of the addition rate of the dried material I to the mixed solution III is 0.40-0.58 g / mL, and the ratio of the droplet rate of the first impregnation liquid to the dried material I is 0.11-0.42 mL / g.

21. The preparation method according to claim 12, characterized in that In step (4), at least one auxiliary agent containing fluorine, phosphorus, silicon or boron is introduced into the first impregnation solution, and the amount of the auxiliary agent added is 15% to 30% of the total mass of the molybdenum oxide in the first impregnation solution.

22. The preparation method according to claim 21, characterized in that In step (4), the amount of the additive added is 18% to 26% of the total mass of molybdenum oxide in the first impregnation solution.

23. The preparation method according to claim 12, characterized in that In step (4), the amount of the first impregnation liquid used is 15% to 45% of the saturated water absorption of the dried material I.

24. The preparation method according to claim 12, characterized in that In step (5), the calcination adopts programmed temperature rise, the heating rate is 1°C / min~3°C / min, the calcination temperature is 550~750°C, the calcination time is 3~8h, and the calcination atmosphere is one or more of nitrogen, water vapor or air.

25. The preparation method according to claim 12, characterized in that In step (5), the calcination atmosphere is air.

26. The preparation method according to claim 12, characterized in that In step (6), the carbohydrate aqueous solution is an aqueous solution of starch and / or monosaccharides, and the mass concentration of starch and / or monosaccharides in the solution is 20.0% to 40.0%; the monosaccharides include one or more of glucose, ribose, and fructose.

27. The preparation method according to claim 26, characterized in that In step (6), ammonium bicarbonate is added to the carbohydrate aqueous solution as a pore-enlarging agent, the mass concentration of ammonium bicarbonate in the carbohydrate aqueous solution is 15.0% to 35.0%, and the soaking time is 0.5 min to 10 min.

28. The preparation method according to claim 26, characterized in that The soaking time is 3.0 min to 6.0 min.

29. The preparation method according to claim 12, characterized in that In step (6), the carbonization conditions are: pre-oxidation in an air atmosphere at a temperature of 160-320°C for 4-20 hours; then carbonization in a nitrogen atmosphere at a temperature of 400-700°C for 2-10 hours; and / or, in step (7), the calcination method adopts programmed temperature rise, the heating rate is 1°C / min-3°C / min, the calcination temperature is 400-550°C, and the calcination time is 3-6 hours.

30. The preparation method according to claim 12, characterized in that In step (6), the carbonization conditions are: pre-oxidation for 3 to 16 hours at a temperature of 240 to 320° C. in an air atmosphere; and then carbonization for 2 to 10 hours at a temperature of 450 to 650° C. in a nitrogen atmosphere.

31. Use of the hydrodemetallization catalyst according to any one of claims 1 to 11 in a residue hydrotreating process.

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