Preparation and use of a fluid catalytic cracking catalyst resistant to nickel contamination

Abstract

The present application relates to a kind of preparation and application of anti-nickel contaminated fluidized catalytic cracking catalyst, the preparation method of the anti-nickel contaminated fluidized catalytic cracking catalyst includes the preparation manganese oxide-aluminum oxide-phosphorus oxide material by manganese source, phosphorus source, aluminum source and optional coating regulator, the step of forming coating on cracking active microspheres with slurry containing the material, calcination.The catalyst is used for catalytic cracking of heavy oil containing nickel, under certain nickel pollution conditions, can effectively reduce hydrogen methane ratio, reduce coke yield, relieve gas compressor pressure.

Description

Invention Field

[0001] This invention relates to catalytic cracking catalysts in fluidized catalytic cracking processes, and particularly to the preparation and application of a catalyst for improving the nickel tolerance of heavy oil catalytic cracking to process heavy feedstocks. Background of the Invention

[0002] Fluidized catalytic cracking (FCC) technology is a crucial method for the secondary processing of heavy oil products worldwide, with the catalytic cracking catalyst playing a key role. With the increasing depletion of high-quality light crude oil resources globally and the expansion of delayed coking capacity, refineries, in an effort to increase profits, blend large proportions of inferior oils such as residue oil, coking wax oil, and deasphalted oil into their catalytic cracking units. These oils contain contaminating metals such as Ni and V, which continuously deposit on the catalyst surface during processing, poisoning the catalyst and severely impacting the stable operation of the catalytic cracking unit and the distribution of cracked products. For example, Ni can initiate dehydrogenation, significantly increasing H2 and coke yields, raising the hydrogen-to-methane ratio (the proportion of hydrogen to methane in the products), and the high hydrogen yield places greater pressure on the gas compressor. V, under high-temperature hydrothermal conditions, easily interacts with zeolite, damaging its skeletal structure and affecting conversion efficiency. Metal contamination can also affect high-value products such as gasoline and LPG.

[0003] Refineries both domestically and internationally typically suppress the dehydrogenation toxicity of nickel by adding passivating nickel agents during the reaction process. Passivating nickel agents are often injected into the cracking reactor in oil-soluble or water-soluble liquid form. During the reaction, their effective components contact the catalyst surface and react with the "active nickel" on the catalyst surface, rendering it non-toxic. Antimony has the best passivation effect on nickel toxicity; therefore, antimony-based metal passivating agents are currently the most commonly used in China. However, when antimony-based passivating nickel agents are added to catalytic cracking units, the leaching toxicity of antimony metal from the spent catalytic cracking catalyst often exceeds the Class III standard limit of 0.5 mg / L for 100 antimony in the "Surface Water Quality Standard" (GB / T14848-2017), posing a certain environmental risk to the spent catalytic cracking catalyst. The 2021 edition of the "National Hazardous Waste List" revised item 251-017-50 to "spent catalysts generated from catalytic cracking using passivating nickel agents in petroleum refining," meaning that catalytic cracking catalysts with added passivating nickel agents are hazardous waste. Therefore, in the face of increasingly stringent environmental protection requirements, preparing catalysts with high nickel tolerance, and passivating the active nickel on the catalyst surface without using highly toxic antimony Sb, is an important means of reducing hazardous waste at the source.

[0004] To reduce the adverse effects of vanadium on catalytic cracking catalysts, existing technologies often use catalytic cracking catalysts or additives with vanadium resistance or vanadium capture functions. Commonly used vanadium-resistant components are rare earth elements, such as lanthanides. It is believed that rare earth oxides can form stable compounds with V2O5, thereby inhibiting the destructive effect of vanadium on molecular sieves. There are also reports on the application of rare earth elements' tolerance to nickel, but the effect is not ideal.

[0005] US4919787A describes a catalytic cracking catalyst containing a metal passivation material, which includes precipitated porous rare earth oxides, alumina, and aluminum phosphate precipitates. The passivation material can be coated onto the cracking catalyst, can be part of the catalyst matrix, or can be added as discrete particles to the cracking operation. However, this material has limited effectiveness in reducing the hydrogen-to-methane ratio. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a high nickel tolerance fluidized catalytic cracking catalyst and its preparation method, which can reduce the coke yield and reduce the hydrogen-methane ratio in heavy oil catalytic cracking under high nickel pollution conditions.

[0007] This invention provides a method for preparing a nickel-contaminated fluidized bed catalytic cracking catalyst, comprising the following steps:

[0008] (1) Provide cracking active microspheres (or catalytic cracking catalyst precursor microspheres), whose average particle size is usually 60-80 micrometers;

[0009] (2) Preparation of manganese oxide-alumina-phosphorus oxide materials;

[0010] The manganese source, phosphorus source, aluminum source, and optional coating modifier are combined to form a colloidal slurry, which is called the first slurry.

[0011] The colloidal slurry has a solid content of 1-20% by weight, and the final pH value is adjusted to 5.5-10 by a coating conditioner. Preferably, its dry basis (solid product after calcination at 800°C for 1 hour) has the following weight ratio:

[0012] (0-6)Na2O·(65-95)Al2O3·(0-3)SiO2·(0.1-10)P2O5·(0.5-35)MnO;

[0013] The coating modifier is selected from one or more basic inorganic ammonium compounds and organic bases, wherein the organic base is, for example, an organic amine and / or a quaternary ammonium base.

[0014] Option (3): The first slurry is dried, then roasted, ground, or acid-treated to form the second slurry.

[0015] (4) Coating microspheres containing cracking active components with manganese oxide-alumina-phosphorus oxide material: coating the surface of cracking active microspheres with a first slurry and / or a second slurry; preferably coating the surface of cracking active microspheres with the first slurry;

[0016] (5) Drying and calcining to obtain a nickel-contaminated fluidized bed catalytic cracking catalyst with an anti-metal contamination coating, wherein, on a dry basis, the weight of the cracking active microspheres in the nickel-contaminated fluidized bed catalytic cracking catalyst accounts for 80-99.5% and the coating accounts for 0.5-20% by weight.

[0017] According to the present invention, the first slurry containing a manganese oxide-aluminum oxide-phosphorus oxide material is a sol-gel compound, wherein metallic manganese exists in a bound state with alumina or aluminum phosphate and is substantially in a non-ionic state in the sol / gel solution. The first slurry can be prepared by forming a first mixture comprising at least one aluminum source (+3 valence), a metallic manganese source, and an acidic phosphorus source such as phosphoric acid; a coating modifier is also added to the first mixture. The coating modifier maintains the pH of the first slurry at about 5.5 to about 10, preferably about 6.5 to about 9. A coating modifier solution with a concentration of 0.1 to 20% by weight can be added, and the solid content of the first slurry is 1 to 20% by weight, for example, 2 to 10% by weight.

[0018] The coating modifier is a non-alkaline inorganic ammonium compound and / or an organic base, such as an organic amine and / or a quaternary ammonium base, such as alkyl-containing ammonium hydroxide (or tetraalkylammonium hydroxide). In one embodiment, the coating modifier is one or more of ammonium hydroxide, ammonia, tetraalkylammonium hydroxide, and alkylamines, wherein the alkyl group in the tetraalkylammonium hydroxide and alkylamine is methyl-, ethyl-, propyl-, butyl-, or a combination thereof; for example, tetraalkylammonium hydroxide can be tetramethylammonium hydroxide, and the alkylamine can be n-propylamine.

[0019] According to the preparation method of the nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, the manganese source is one or more of manganese oxide, manganese hydroxide, and manganese salt; the manganese salt can be selected from one or more of manganese nitrate, manganese sulfate, manganese phosphate, or manganese chloride; the alumina source can be one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum chloride, gibbsite, boehmite, boehmite, amorphous alumina, and aluminum sol; the phosphorus source is, for example, one or more of phosphoric acid and aluminum phosphate sol.

[0020] According to the preparation method of the nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, in step (2), the method for forming a colloidal slurry from the manganese source, phosphorus source, aluminum source and coating modifier is as follows:

[0021] Manganese source, alumina source, phosphorus source, and water are mixed and stirred evenly. A coating conditioner is added to adjust the pH value to 5.5–10, preparing a colloidal slurry. Preferably, the above process is carried out at 10–80°C. Optionally, the preparation of the first slurry may also include an aging process, with an aging temperature of, for example, 50–150°C, or for example, 70–130°C; and an aging time preferably of 0.5–6 hours. Preferably, acidic aluminum source, manganese source, acidic phosphorus source, and water are first mixed under acidic conditions, then an alkaline aluminum source is added, and the pH value is adjusted using a coating conditioner. After stirring evenly, the mixture is aged.

[0022] According to the preparation method of the nickel-contaminated fluidized catalytic cracking catalyst provided by the present invention, in one embodiment, step (2) is as follows:

[0023] First, an acidic mixture is formed by combining an acidic aluminum source, a manganese source, a phosphorus source, and water. Then, an alkaline aluminum source is added. The preferred weight ratio of the acidic aluminum source to the alkaline aluminum source (calculated as alumina) is 1.5–2.5:1. The pH is then adjusted to 5.5–9, for example, 6.7–9.0, using a coating modifier. The product prepared in this way can achieve good anti-nickel contamination while also providing a good catalyst cracking effect, such as high conversion rate and gasoline yield. The acidic aluminum source is preferably one or more of alumina sol, boehmite (e.g., boehmite slurry), aluminum sulfate, aluminum chloride, and aluminum nitrate. The phosphorus source is preferably phosphoric acid, and the alkaline aluminum source is preferably sodium aluminate. The manganese source is one or more of manganese chloride, manganese nitrate, manganese sulfate, manganese oxide, and manganese hydroxide.

[0024] According to the method for preparing a nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, the coating accounts for 1-20% by weight of the nickel-contaminated fluidized bed catalytic cracking catalyst on a dry basis, and further, the coating accounts for 2% to 10% by weight of the nickel-contaminated fluidized bed catalytic cracking catalyst on a dry basis.

[0025] According to the preparation method of the nickel-contamination-resistant fluidized bed catalytic cracking catalyst provided by the present invention, the calcination in step (5) is carried out at a temperature of 200-600°C and for a time of 0.1-6 hours, for example, 1-4 hours.

[0026] According to the method for preparing the nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, manganese, calculated as MnO, accounts for 0.1% to 6% of the dry weight of the nickel-contaminated fluidized bed catalytic cracking catalyst, preferably 0.3% to 3%.

[0027] According to the method for preparing a nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, step (1) provides cracking active microspheres with an average particle size of 60-80 micrometers, wherein the cracking active microspheres can be a fully synthetic catalytic cracking catalyst or a catalytic cracking catalyst synthesized by a semi-synthetic method. In one embodiment, the cracking active microspheres, on a dry basis, comprise 5% to 65% molecular sieve, 10% to 75% binder, and 5% to 65% clay; the molecular sieve is, for example, one or more of Y-type molecular sieve, ZSM-5 molecular sieve, and β-molecular sieve; the binder is, for example, one or more of alumina binder, silica binder, and silica-alumina binder.

[0028] According to the method for preparing a nickel-contaminated fluidized bed catalytic cracking catalyst provided by the present invention, the sodium oxide content of the nickel-contaminated fluidized bed catalytic cracking catalyst is not more than 0.4% by weight. If the sodium oxide content in the product of step (5) exceeds 0.4% by weight, the preparation method further includes a sodium reduction treatment step, wherein the sodium reduction treatment is selected from one of the following methods: Method 1, performing sodium reduction treatment on the catalyst precursor microspheres before spraying; Method 2, performing sodium reduction treatment on the catalyst microspheres after spraying, drying, and calcination. Sodium reduction methods are well known to those skilled in the art, for example, exchange can be performed using ammonium salt solutions and / or acid solutions.

[0029] The present invention further provides a nickel-contamination-resistant catalytic cracking catalyst, comprising cracking active microspheres and an anti-contamination metal coating on the surface of the cracking active microspheres, wherein the weight ratio of the anti-contamination metal coating to the weight of the cracking active microspheres is 0.005-0.2:0.8-0.995, preferably 0.01-0.1:1; the anti-contamination metal coating comprises 5%-40% manganese oxide (based on MnO), 0.1%-10% phosphorus oxide (based on P2O5), and 50%-95% aluminum oxide (based on Al2O3).

[0030] According to the nickel-contaminated catalytic cracking catalyst provided by the present invention, the ratio of the mass concentration of metallic manganese in the shell of the nickel-contaminated catalytic cracking catalyst to the mass concentration of manganese inside the nickel-contaminated catalytic cracking catalyst is >50.

[0031] The anti-metal coating in the catalytic cracking catalyst of this invention can be used for EPMA microarea analysis to detect and determine the concentrations of Mn, P, and Al elements, and further, the coating thickness can be measured. For example, EPMA can be used to perform line scans of any selected 3-20 particle cross-sections to detect the elemental concentrations at different depths of the microspheres.

[0032] According to the nickel-contamination-resistant fluidized bed catalytic cracking catalyst provided by the present invention, the coating thickness is in the range of 100 nm to 5 μm, generally in the range of 200 nm to 2 μm, for example, 0.5 to 1.5 μm.

[0033] According to the invention, the coating content relative to the nickel-fouling fluidized catalytic cracking catalyst is 0.5-20% by weight. Preferably, the coating content is advantageously as low as about 0.5% by weight, preferably at least 1% by weight, and as high as about 10% by weight, such as preferably about 6% by weight, and most preferably about 5% by weight. For example, the nickel-fouling fluidized catalytic cracking catalyst may contain 1% to 6% by weight or 2% to 5% by weight of the coating.

[0034] This invention further provides a method for cracking nickel-containing feedstock oil, comprising contacting the nickel-containing feedstock oil with the nickel-resistant fluidized bed catalytic cracking catalyst provided by this invention or the fluidized bed catalytic cracking catalyst prepared by the method for preparing the nickel-resistant fluidized bed catalytic cracking catalyst provided by this invention in a fluidized reactor, such as a riser reactor, a descending bed reactor, or a fluidized bed reactor, followed by rapid separation and regeneration. Reaction conditions, for example, include contacting the feedstock oil at 400°C to 680°C (e.g., 480-650°C) in the presence of an inert gas and / or water vapor atmosphere, for a reaction time of 0.1 to 1 min (e.g., 1 to 10 s).

[0035] According to the nickel-containing feedstock cracking method provided by the present invention, during the reaction regeneration process, the outermost layer of the nickel-resistant catalytic cracking catalyst is most easily worn, continuously exposing new coating surfaces, which is beneficial for nickel resistance. In one embodiment, the wear resistance of the coating is slightly lower than that of the cracking active component, thus the outermost layer of the coating material can act as a sacrificial metal trap. The outermost layer gradually peels off from the catalyst, and as the coating wears, new coating sites are continuously exposed, thereby more effectively removing nickel from the FCC catalyst, maintaining the overall metal level in the FCC unit at a low level, and extending the catalyst's service life.

[0036] The nickel-contamination-resistant fluidized bed catalytic cracking catalyst provided by this invention exhibits superior nickel resistance, achieving better nickel contamination resistance even with lower amounts of anti-metal contamination components. It reduces nickel contamination dehydrogenation performance, thereby lowering hydrogen yield and the hydrogen-to-methane ratio. Particularly effective in reducing the hydrogen-to-methane ratio in heavy oil catalytic cracking under high nickel contamination conditions, it effectively alleviates the load on the gas compressor. Preferably, the nickel-contamination-resistant catalyst provided by this invention achieves lower coke dry gas yield and higher gasoline yield while maintaining a lower hydrogen-to-methane ratio.

[0037] The present invention provides a method for preparing an anti-nickel contamination fluidized bed catalytic cracking catalyst. This method involves applying the anti-contamination component to the surface of the cracking catalytic active component to form a nickel-containing coating, which acts as a stabilizing and protective layer against contaminating metals. This coating can be firmly bonded to the catalyst. The resulting anti-nickel contamination fluidized bed catalytic cracking catalyst effectively reduces the dehydrogenation activity of nickel and minimizes its impact on cracking activity. Preferably, when using organic base coating modifiers such as tetraalkylammonium hydroxide and alkylamines, the specific surface area and pore volume of the obtained anti-nickel contamination catalytic cracking catalyst decrease by no more than 10% relative to the original catalyst (cracking active microspheres). This improves the nickel-containing performance of the anti-metal coating without affecting the heavy oil conversion performance of the anti-nickel contamination catalyst. Using both acidic and basic aluminum sources, and adding a manganese source to the acidic aluminum source, further improvements in anti-nickel contamination and cracking reaction effects are achieved, such as higher conversion rates and higher gasoline yields. Attached Figure Description

[0038] Figure 1 The EPMA (electron probe microanalysis) image of Mn in C1 of the catalyst prepared in Example 1 clearly shows the distribution of Mn in the coating on the catalyst surface.

[0039] Figure 2 The EPMA plot of Mn in D3 of the catalyst prepared in Comparative Example 3 shows the distribution of Mn metal in the catalyst.

[0040] The highlighted areas in the attached image indicate high element content. Figure 1 As can be seen, Mn is mainly distributed on the outer surface of the catalyst. Detailed Implementation

[0041] The following embodiments will further illustrate the present invention, but are not intended to limit the invention.

[0042] The catalyst precursor microspheres (catalytic cracking catalyst precursor microspheres) used in the examples and comparative examples were self-prepared catalytic cracking catalysts. The active microspheres were catalytic cracking catalysts, denoted as Cat-A, and their basic chemical composition is shown in Table 1. This chemical composition was determined by X-ray fluorescence spectrometry (XRF), and the specific procedures were in accordance with ASTM D7085-04 (2010) Standard Guidelines for the Determination of Chemical Elements in Fluidized Catalytic Cracking Catalysts—Guidelines for X-ray Fluorescence Spectrometry.

[0043] Specific surface area determination of samples: See: NB / SH / T 0959-2017 Determination of specific surface area of ​​catalytic cracking catalysts, static nitrogen adsorption capacity method;

[0044] The average pore size was determined by the low-temperature nitrogen adsorption-desorption method and the pore size distribution was calculated by the BJH method.

[0045] The pore volume was determined by the water droplet pore volume method, see NB / SH / T 0955-2017 Determination of Pore Volume of Catalytic Cracking Catalyst by Water Droplet Method.

[0046] Particle size distribution was determined using the laser particle size distribution method, see NB / SH / T 0951-2017 Determination of particle size distribution of catalytic cracking catalysts by laser scattering method.

[0047] Wear index measurement: NB / SH / T 0964-2017 Determination of wear index of catalytic cracking catalyst - straight tube method.

[0048] The surface layer thickness range measurement method of the embodiment is as follows: In the EPMA image, 10 cross-sectional views of particles are randomly selected. The surface layer thickness of each particle cross-section is measured by randomly using a radial direction to obtain the distribution range of particle thickness. The arithmetic mean of the 10 data is taken as the average thickness.

[0049] Industrial-grade aluminum sol, supplied by Sinopec Catalyst Company Qilu Branch, industrial product, solid content 22% by weight.

[0050] Boehmite supplied by Sinopec Catalyst Company, Qilu Branch, industrial grade, solid content 73.76% by weight.

[0051] Preparation of Cat-A cracking active microspheres

[0052] 200 parts by weight of boehmite (on a dry basis, product of Shandong Aluminum Company) were added to deionized water and 24 parts by weight of 35% hydrochloric acid, and the mixture was slurried to prepare boehmite with a solid content of 12% by weight. Then, 100 parts by weight of alumina sol (on a dry basis), 340 parts by weight of kaolin (on a dry basis), and 360 parts by weight of DASY.2.0 molecular sieve (product of Qilu Branch of China Petrochemical Catalyst Co., Ltd.) were added. After stirring for 0.5 h, the mixture was spray-dried, calcined at 550 °C for 2 h, and washed twice with 2% ammonium chloride solution to obtain cracking active microspheres (or basic catalytic cracking catalyst precursor microspheres), denoted as Cat-A. The basic chemical composition of Cat-A is shown in Table 1, and the average particle size is about 78 μm.

[0053] Table 1

[0054] Component Name Cat-A Cl.%(W) 0.490 <![CDATA[Na2O.%(W)]]> 0.0458 <![CDATA[Al2O3.%(W)]]> 53.4 <![CDATA[SiO2.%(W)]]> 42.7 <![CDATA[P2O5.%(W)]]> 0.107 <![CDATA[SO3.%(W)]]> 1.67 <![CDATA[K2O.%(W)]]> 0.196 CaO.% (W) 0.057 <![CDATA[TiO2%(W)]]> 0.288 <![CDATA[La2O3,%(W)]]> 0.309 <![CDATA[CeO2,%(W)]]> 0.607

[0055] Example 1

[0056] A 300 ml solution of aluminum sulfate (Al2(SO4)3) with a concentration of 40 g Al2O3 / L was placed in a gelling tank at 30°C. 60 g of manganese chloride solution (10% by mass, calculated as MnO) and 2.58 g of phosphoric acid were added. Then, 160 ml of sodium aluminate solution with a concentration of 40 g Al2O3 / L was added. The pH was further adjusted to 7.5 using tetramethylammonium hydroxide solution (10% by weight). After stirring thoroughly for 1 hour, the temperature was increased to 120°C and aged for 3 hours. The mixture was then vacuum filtered, washed with decationized water, and dried at 150°C for 2 hours to obtain manganese oxide-alumina-phosphorus oxide-1. Its surface area is 283 m². 2 / g, pore volume is 0.78cm 3 / g, with an average pore size of 7.2nm, and its properties are shown in Table 2.

[0057] Take 4g of manganese oxide-alumina-phosphorus oxide-1 (on a dry basis), dilute it to 30g with distilled water, add 0.46g of hydrochloric acid and stir thoroughly. Then, use a spray device to rapidly spray 95g of continuously stirred Cat-A cracking active microspheres. After further thorough stirring, dry at 120℃ for 2h, and then calcine at 500℃ for 2h to obtain catalyst C1. The Mn content of C1 is approximately 1% by mass as MnO, and its properties are shown in Table 3.

[0058] Example 2

[0059] 300 ml of aluminum sulfate (Al2(SO4)3) with a concentration of 40 g Al2O3 / L was placed in a gelling tank and the temperature was controlled at 30℃. 60 g of manganese chloride solution with a MnO content of about 10% by mass was added, along with 2.58 g of phosphoric acid. Then, 160 ml of sodium aluminate solution with a concentration of 40 g Al2O3 / L was added. The pH was further adjusted to 7.5 using tetramethylammonium hydroxide. After stirring thoroughly for 1 h, the mixture was aged at 80℃ for 6 h to obtain a manganese oxide-aluminum oxide-phosphorus oxide-2 colloidal slurry. Its properties are shown in Table 2.

[0060] Take 90 ml of manganese oxide-alumina-phosphorus oxide-2 colloidal slurry and spray it directly onto 95 g of Cat-A that is continuously heated and stirred at 120 °C using an ultrasonic spraying device. After further thorough stirring, dry at 120 °C for 2 h and then calcine at 500 °C for 2 h to obtain the catalyst precursor. The Mn content is approximately 1.0% by mass, calculated as MnO. Further washing with ammonium sulfate solution reduces the Na content to 0.3% by weight to obtain catalyst C2, the properties of which are shown in Table 3.

[0061] Example 3

[0062] Referring to Example 2, compared with manganese oxide-aluminum oxide-phosphorus oxide-2, tetramethylammonium hydroxide was replaced with ammonia (7% by weight) to adjust the pH, while all other parameters remained unchanged, resulting in manganese oxide-aluminum oxide-phosphorus oxide-3, the properties of which are shown in Table 2. Similarly, in Example 2, manganese oxide-aluminum oxide-phosphorus oxide-3 was used instead of manganese oxide-aluminum oxide-phosphorus oxide-2 to obtain a C3 catalyst, the properties of which are shown in Table 3.

[0063] Example 4

[0064] Preparation of manganese oxide-aluminum oxide-phosphorus oxide-4: 310 ml of aluminum sulfate (Al2(SO4)3) solution with a concentration of 40 g Al2O3 / L was placed in a gelling tank and the temperature was controlled at 30℃. 60 g of manganese chloride solution with a MnO content of about 10% was added, along with 0.26 g of phosphoric acid and 160 ml of sodium aluminate solution with a concentration of 40 g Al2O3 / L. The pH was further adjusted to 8 using tetramethylammonium hydroxide solution and aged at 80℃ for 6 h to obtain manganese oxide-aluminum oxide-phosphorus oxide-4 colloidal slurry.

[0065] 90 ml of a manganese oxide-alumina-phosphorus oxide-4 colloidal slurry was directly sprayed onto 95 g of Cat-A, which was continuously heated and stirred at 120 °C, using an ultrasonic spraying device. After further thorough stirring, it was dried at 120 °C for 2 h and then calcined at 500 °C for 2 h to obtain the catalyst C4 precursor. The Mn mass fraction of the C4 precursor was approximately 1.0%. Further washing with ammonium sulfate solution reduced the Na content to 0.3% by mass, yielding catalyst C4. Its properties are shown in Table 3.

[0066] Example 5

[0067] Catalyst C5 was prepared according to the method of Example 2, except that manganese oxide-aluminum oxide-phosphorus oxide-5 was used instead of manganese oxide-aluminum oxide-aluminum phosphate-2.

[0068] Preparation of manganese oxide-aluminum oxide-phosphorus oxide-5: 460 ml of aluminum sulfate (Al2(SO4)3) with a concentration of 40 g Al2O3 / L was placed in a gelling tank and the temperature was controlled at 30℃. 60 g of manganese chloride solution with a MnO content of about 10% by mass was added, and 2.58 g of phosphoric acid was added. The pH value was further adjusted to 7.5 by using tetramethylammonium hydroxide according to the molar ratio. After stirring thoroughly for 1 h, the mixture was aged at 80℃ for 6 h to obtain a manganese oxide-aluminum oxide-phosphorus oxide-5 colloidal slurry. Its properties are shown in Table 2.

[0069] Comparative Example 1

[0070] Cat-A undergoes no processing.

[0071] Comparative Example 2

[0072] Preparation of alumina-phosphorus oxide-1: 300 ml of aluminum sulfate solution with a concentration of 40 g Al2O3 / L was placed in a gelling tank and the temperature was controlled at 30℃. 2.58 g of phosphoric acid was added, followed by 160 ml of sodium aluminate solution with a concentration of 40 g Al2O3 / L to adjust the pH to 8-9. After stirring thoroughly for 1 h, the temperature was increased to 120℃ and aged for 3 h. The mixture was then vacuum filtered, washed with decationized water, and dried to obtain alumina-phosphorus oxide-1.

[0073] Take 4g of alumina-phosphorus oxide-1 (dry basis), add 2g of industrial manganese chloride (calculated as MnO), dilute with distilled water to 30g, stir for a period of time, then add 0.46g of hydrochloric acid and stir thoroughly. Spray the mixture onto 95g of Cat-A catalyst precursor using a homogenizing sprayer. After further thorough stirring, dry at 120.4℃ for 2h, then calcine at 500℃ for 2h to obtain catalyst D2. The Mn mass fraction of D2 is approximately 1%, and its properties are shown in Table 3.

[0074] Comparative Example 3

[0075] Add 16.2 kg of aluminum sol to 5.4 kg of decationized water and mix well. Add 7.1 kg of rettoiter under stirring. Heat to 60°C and stir for 30 minutes. Then add 1138 g of manganese chloride (MnCl2·4H2O, produced by Beijing Chemical Reagent Company) as MnO. Stir for 60 minutes to obtain a slurry with a solid content of 35% by mass, denoted as T1.

[0076] 200g of boehmite (dry basis, produced by Shandong Aluminum Industry Co., Ltd.) was mixed with an appropriate amount of deionized water and 24g of hydrochloric acid to prepare a boehmite solution with a solid content of 12%. Then, 100g of alumina sol (dry basis), 270g of kaolin (dry basis), 360g of DASY 2.0 (dry basis), and 70g of T1 (dry basis) were added. After thorough homogenization and stirring for 0.5h, the mixture was spray-dried, further calcined, and washed with ammonium sulfate to obtain catalyst D3 with a Mn content of approximately 0.7% by mass. Its properties are shown in Table 3. EPMA testing showed that the Mn metal was dispersed in the catalyst.

[0077] Comparative Example 4

[0078] 200 ml of aluminum sulfate (Al2(SO4)3) with a concentration of 40 g Al2O3 / L was placed in a gelling tank and the temperature was controlled at 30℃. 60 g of manganese chloride solution with a MnO content of about 10% by mass was added, along with 2.58 g of phosphoric acid. Then, 133.3 ml of sodium aluminate solution with a concentration of 40 g Al2O3 / L was added. The pH was further adjusted to 7.5 using tetramethylammonium hydroxide. After stirring thoroughly for 1 h, 5.0 g of kaolin (on a dry basis) was added and stirring was continued for 0.5 h. The mixture was then aged at 80℃ for 6 h to obtain a manganese oxide-alumina-phosphorus oxide-kaolin-D4 colloidal slurry with a SiO2 content of about 10%.

[0079] Take 90 ml of manganese oxide-alumina-phosphorus oxide-kaolin-D4 colloidal slurry and spray it directly onto 95 g of Cat-A that is continuously heated and stirred at 120 °C. After further thorough stirring, dry at 120 °C for 2 h, and then calcine at 500 °C for 2 h to obtain the catalyst precursor. The Mn content is approximately 1.0% by mass, calculated as MnO. Further washing with ammonium sulfate solution and distilled water reduces the Na content to 0.3%, yielding catalyst D4. See Table 3.

[0080] Reaction Examples

[0081] This embodiment illustrates the anti-metal properties of the heavy oil cracking catalyst provided by the present invention.

[0082] Catalysts C1, C2, C3, C4, and C5 were subjected to a cyclic contamination method on an ACE D100 unit. Nickel naphthenate and vanadium naphthenate were dissolved in distillate oil at a mass ratio of 5:2 for multiple cyclic reactions until the Ni content on the catalyst was approximately 4500 ppm (mass) and the V content was approximately 1500 ppm (mass). The samples after cyclic contamination were numbered C1w, C2w, C3w, C4w, and C5w, respectively. Samples C1w, C2w, C3w, C4w, and C5w were then aged in a fixed bed at 800℃ with 100% steam for 12 hours, and their crystallinity was tested. The results are shown in Table 3. They were then evaluated using an ACE fluidized bed unit. The properties of the feedstock for ACE evaluation are shown in Table 4, and the evaluation conditions and results are shown in Table 5.

[0083] Reaction ratio

[0084] These comparative examples illustrate the anti-metal properties of the heavy oil cracking catalysts provided in Comparative Examples 1-4.

[0085] Catalysts Cat-A, D2, D3, and D4 were subjected to a cyclic contamination method on an ACE D100 unit. Nickel naphthenate and vanadium naphthenate were dissolved in the distillate oil at a 5:2 ratio and repeatedly cyclically reacted until the Ni content on the catalyst was approximately 4500 ppm and the V content was 1500 ppm. The samples after cyclic contamination were numbered Cat-Aw, D2w, and D3w, respectively. Then, samples Cat-Aw, D2w, D3w, and D4w were aged in a fixed bed at 800℃ with 100% steam for 12 hours, and the crystallinity was tested. The results are shown in Table 3. Subsequently, they were evaluated using an ACE fluidized bed unit. The properties of the feedstock for ACE evaluation are shown in Table 2, and the evaluation conditions and results are shown in Table 5.

[0086] Table 2. Low-temperature nitrogen adsorption test results of manganese oxide-alumina-phosphorus oxide coating material colloidal slurry after drying.

[0087]

[0088] Table 3

[0089] Catalyst name after pollution C1w C2w C3w C4w C5w Cat-Aw D2w D3w D4w Average shell thickness, μm 0.8 0.95 0.73 0.81 0.83 - 0.98 - 0.90 The ratio of Mn concentration in the shell to that in the interior Approximately 100 Approximately 80 Approximately 150 Approximately 130 140 - Approximately 5 Approximately 1 Approximately 100 <![CDATA[Specific surface area m 2 / g]]> 301 303 290 296 288 312 298 308 305 Pore ​​volume, ml / g 0.34 0.35 0.30 0.31 0.29 0.38 0.35 0.37 0.34 Crystallinity after aging of contaminants, % 16 14 14 15 15 17 10 14 15

[0090] Table 4

[0091]

[0092] Table 5

[0093] Catalyst name C1w C2w C3w C4w C5w Cat-Aw D2w D3w D4w Cracking reaction temperature, °C 500 500 500 500 500 500 500 500 500 Agent-to-oil ratio, wt / wt 4.02 4.02 4.02 4.02 4.02 4.02 4.02 4.02 4.02 Yield wt%: dry air 1.99 1.92 2.08 1.98 2.03 2.29 1.58 2.21 2.05 Liquefied gas 12.75 12.34 11.1 12.08 11.68 12.03 10.45 12.78 12.21 coke 9.49 9.36 10.05 9.92 10.09 11.62 7.52 10.85 10.95 gasoline 45.55 45.81 45.12 44.13 44.09 43.23 37.19 41.55 43.98 diesel fuel 18.5 18.52 19.09 18.76 19.22 19.57 20.2 20.75 18.87 heavy oil 11.72 12.05 12.56 13.13 12.89 11.26 23.06 11.86 11.94 Conversion rate, wt% 69.78 69.43 68.35 68.11 67.89 69.17 56.74 67.39 69.19 hydrogen 0.31 0.32 0.35 0.33 0.34 0.56 0.28 0.48 0.43 methane 0.84 0.83 0.85 0.84 0.86 0.86 0.62 0.85 0.82 Ethane 0.43 0.39 0.46 0.42 0.43 0.44 0.32 0.46 0.41 ethylene 0.41 0.38 0.42 0.39 0.4 0.43 0.36 0.42 0.39 propane 0.87 0.85 0.73 0.84 0.78 0.81 0.49 0.93 0.76 propylene 3.7 3.93 3.41 3.71 3.66 3.66 3.34 3.61 3.67 n-Butane 0.73 0.64 0.61 0.62 0.64 0.62 0.39 0.76 0.58 Isobutane 3.22 2.96 2.69 2.86 2.75 2.88 2.05 3.23 3.21 C4 olefins 4.23 3.96 3.66 4.05 3.85 4.06 4.18 4.25 3.99 Hydrogen-methane ratio (mol ratio) 2.95 3.08 3.29 3.14 3.16 5.21 3.61 4.52 4.2

[0094] As can be seen from the data in Tables 3 and 5, compared with the catalysts D1 to D4 provided in the comparative example, under certain nickel contamination conditions, the C1 to C5 catalysts, with lower Mn content, can stabilize Mn metal on the catalyst surface, stabilize catalyst activity, reduce hydrogen and coke yields, significantly reduce the hydrogen-methane ratio, and have a higher gasoline yield.

Claims

1. A method for preparing a nickel-contaminated fluidized bed catalytic cracking catalyst, comprising: (1) Provide cracking-active microspheres; The cracking-active microspheres are either fully synthetic catalytic cracking catalysts or semi-synthetic catalytic cracking catalysts. (2) Preparation of manganese oxide-alumina-phosphorus oxide materials; The first slurry is formed by manganese source, phosphorus source, aluminum source and optional coating modifier; The first slurry has a solid content of 1-20% by weight, a pH value of 5.5-10, and a dry basis weight ratio of the first slurry as follows: (0-6)Na2O·(65-95)Al2O3·(0-3)SiO2·(0.1-10)P2O5·(0.5-35)MnO; The coating modifier is selected from one or more alkaline inorganic ammonium compounds and organic bases; The manganese source is a manganese salt; Option (3) is to dry the first slurry, optionally roast it, grind it, optionally add acid to it to form the second slurry; (4) Coating cracking active microspheres with manganese oxide-alumina-phosphorus oxide material: Coating the surface of cracking active microspheres with the first slurry and / or the second slurry; (5) Drying and calcining to obtain a nickel-resistant fluidized catalytic cracking catalyst with a metal-resistant coating, wherein, on a dry basis, the weight of the cracking active microspheres in the nickel-resistant fluidized catalytic cracking catalyst accounts for 80-99.5% and the coating accounts for 0.5-20% by weight.

2. The preparation method according to claim 1, characterized in that, The manganese salt is selected from one or more of manganese nitrate, manganese sulfate, manganese phosphate, or manganese chloride; the aluminum source is one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum chloride, gibbsite, boehmite, boehmite, amorphous aluminum colloid, or aluminum sol; the phosphorus source is one or more of phosphoric acid or aluminum phosphate sol; the coating modifier is one or more of ammonium hydroxide, ammonia, tetraalkylammonium hydroxide, and alkylamine, wherein the alkyl group is methyl-, ethyl-, propyl-, butyl-, or a plurality of thereof.

3. The preparation method according to claim 2, characterized in that, The coating modifier is tetramethylammonium hydroxide and / or n-propylamine.

4. The preparation method according to claim 1, characterized in that, In step (2), the method for forming the first slurry from the manganese source, phosphorus source, aluminum source, and coating modifier is as follows: Manganese source, aluminum source, phosphorus source and water are mixed and stirred evenly. A coating conditioner is added and the pH value is adjusted to 5.5~10 to prepare the first slurry. The process of preparing the first slurry is carried out at 10~80℃.

5. The preparation method according to claim 4, characterized in that, The first slurry is aged during the formation process, with an aging temperature of 50~150℃ and an aging time of 0.5~6 hours.

6. The preparation method according to claim 5, characterized in that, First, acidic aluminum source, manganese source, acidic phosphorus source, and water are mixed under acidic conditions, then an alkaline aluminum source is added, and finally a coating conditioner is used to adjust the pH value before aging.

7. The preparation method according to claim 4 or 6, characterized in that, In step (2): First, an acidic mixture of acidic aluminum source, manganese source, phosphorus source and water is formed, and then an alkaline aluminum source is added; wherein the weight ratio of acidic aluminum source to alkaline aluminum source based on alumina is 1.5 ~ 2.5:1, and then the pH value is adjusted to 5.5 ~ 10 with a coating conditioner.

8. The preparation method according to claim 7, characterized in that, The pH value is adjusted using a coating conditioner, wherein the pH value is 6.7 to 9.

0.

9. The preparation method according to claim 1, characterized in that, The dry basis of the coating accounts for 1-20% by weight of the dry basis of the nickel-contaminated fluidized catalytic cracking catalyst.

10. The preparation method according to claim 9, characterized in that, The dry basis of the coating accounts for 2% to 10% by weight of the dry basis of the nickel-contaminated fluidized catalytic cracking catalyst.

11. The preparation method according to claim 1, characterized in that, The roasting in step (5) is carried out at a temperature of 200~600℃ for 0.1~6 hours.

12. The preparation method according to claim 11, characterized in that, The roasting in step (5) takes 1 to 4 hours.

13. The preparation method according to claim 1, characterized in that, Mn, calculated as MnO, accounts for 0.1% to 6% by weight (dry basis) of the nickel-contaminated fluidized catalytic cracking catalyst.

14. The preparation method according to claim 12, characterized in that, Mn, calculated as MnO, accounts for 0.3% to 3% by weight (dry basis) of the nickel-contaminated fluidized catalytic cracking catalyst.

15. The preparation method according to claim 1, characterized in that, The cracking active microspheres comprise 5%~65 wt% molecular sieve, 10%~75 wt% binder, and 5%~65 wt% clay; the molecular sieve is one or more of Y-type molecular sieve, ZSM-5 molecular sieve, and β molecular sieve; the binder is one or more of alumina binder, silica binder, and silica-alumina binder, and the sodium oxide content of the nickel-resistant fluidized bed catalytic cracking catalyst does not exceed 0.4 wt%.

16. The preparation method according to claim 7, characterized in that, The acidic aluminum source is one or more of aluminum sol, acidified pseudoboehmite slurry, aluminum sulfate, aluminum chloride, and aluminum nitrate; the phosphorus source is phosphoric acid; the alkaline aluminum source is sodium aluminate; and the manganese source is one or more of manganese chloride, manganese nitrate, and manganese sulfate.

17. A nickel-contamination-resistant catalytic cracking catalyst, comprising cracking-active microspheres and an anti-contamination metal coating on the surface of the cracking-active microspheres, wherein, The weight ratio of the anti-fouling metal coating to the cracking active microspheres is 0.005-0.2:0.8-0.995; the anti-fouling metal coating comprises 5%-40% by weight of manganese oxide (based on MnO), 0.1-10% by weight of phosphorus oxide (based on P2O5), and 50%-95% by weight of aluminum oxide (based on Al2O3); the catalytic cracking catalyst is prepared according to the method described in any one of claims 1-16.

18. The nickel-contaminated catalytic cracking catalyst according to claim 17, characterized in that, The weight ratio of the anti-pollution metal coating to the cracking active microspheres is 0.01~0.1:

1.

19. The nickel-contamination-resistant catalytic cracking catalyst according to claim 17, characterized in that, The ratio of the mass concentration of metallic manganese in the shell of the nickel-resistant catalytic cracking catalyst to the mass concentration of manganese inside is >50.

20. The nickel-contaminated catalytic cracking catalyst according to claim 18, characterized in that, The thickness of the coating is 0.1 to 5 micrometers.

21. The nickel-contaminated catalytic cracking catalyst according to claim 20, characterized in that, The coating has a thickness of 0.2-2 micrometers.

22. The nickel-contaminated catalytic cracking catalyst according to claim 21, characterized in that, The coating has a thickness of 0.5 to 1.5 micrometers.

23. A method for cracking nickel-containing feedstock oil, comprising contacting the nickel-containing feedstock oil with a nickel-resistant fluidized catalytic cracking catalyst prepared according to the method for preparing a nickel-resistant fluidized catalytic cracking catalyst according to any one of claims 1-16 or a nickel-resistant catalytic cracking catalyst according to any one of claims 17-22; the reaction conditions include: Under an inert gas and / or water vapor atmosphere, the reaction is carried out at 400℃~680℃ for 0.1~1 min.

Images