Catalytic cracking multifunctional auxiliary agent and preparation method therefor

Abstract

The present invention provides a catalytic cracking multifunctional auxiliary agent and a preparation method therefor. The catalytic cracking multifunctional auxiliary agent comprises the following raw materials: 8%-30% of a first ligand, 5%-30% of a second ligand, 5%-25% of a solubilizer, 10%-25% of metal components, and 5%-30% of water. The catalytic cracking multifunctional auxiliary agent provided by the present invention can inhibit the contamination of metals, such as nickel, vanadium, and calcium, in a catalytic cracking process, can achieve a synergistic effect with a catalyst, and has a synergistic function.

Description

A multifunctional catalytic cracking additive and its preparation method Technical Field

[0001] The invention relates to a catalytic cracking multifunctional auxiliary agent and a preparation method thereof, belonging to the technical field of petrochemical industry. Background Art

[0002] Heavy metals in catalytic cracking feedstocks include nickel, vanadium, iron, sodium, and calcium. Nickel and vanadium are the most abundant and pose the greatest risk. Addressing the contamination of catalysts by metals in feedstocks is crucial for catalytic cracking units, particularly given the increasing deterioration of feedstocks. Furthermore, refineries face an urgent need to reduce costs and increase efficiency. Lowering production costs and improving catalyst performance have long been key goals for these companies.

[0003] To address the problem of heavy metal contamination in catalytic cracking feedstock oil, the most widely used method for suppressing heavy metals is to add metal passivators. The amount of metal passivators added can be adjusted in a timely manner as the concentration of metals such as nickel and vanadium in the feedstock oil changes. This allows for flexible operation, significant results, and requires minimal investment. However, most commercially available metal passivators use toxic antimony and tin as active ingredients, which pose safety and environmental risks when used. The spent catalysts generated after using these metal passivators (containing antimony and tin elements) must be treated as hazardous waste, increasing the difficulty of enterprise management and the cost of hazardous waste disposal. Furthermore, these metal passivators are all water-soluble, have poor miscibility with the catalytic cracking feedstock, and are insufficiently reactive.

[0004] Currently, the most widely used antimony-based nickel passivator is a monofunctional antimony-based nickel passivator. As early as the 1970s, PhilliPs Petroleum Company successfully developed an antimony-based nickel passivator, code-named Phil-Ad-CA. This passivator is a mineral oil solution of dipropyl antimony dithiophosphate, and was industrialized in Borger's FCC unit in 1976. However, this passivator not only has a pungent odor and is difficult to dissolve in common solvents, but also forms precipitation when exposed to light, causing significant trouble in refueling operations. US Pat. No. 4,031,002A and US Pat. No. 4,394,324A disclose this monofunctional antimony-based nickel passivator. Subsequent researchers have made numerous improvements to this antimony-based nickel passivator, developing a series of water-soluble antimony-based nickel passivators that are easy to use and safe to transport. CN1294173A, CN1245198A, and CN1176288A all disclose improved antimony-based nickel passivators. While the addition of antimony-based passivators has a certain effect on limiting nickel contamination of catalysts, antimony itself is toxic. When carried out of the device with the product or deposited on the equipment, it seriously affects human health. Furthermore, the high cost of antimony-based nickel passivators also limits their large-scale use.

[0005] In addition, the Sb-Sn bifunctional metal passivator for nickel and vanadium pollution is currently widely used on the market. The earliest bifunctional metal passivator is the Sb-Sn bifunctional passivator developed by Philips. This passivator is a compound of a single-function nickel passivator and a vanadium passivator. However, when antimony and tin agents are used simultaneously, not only are they highly toxic and poorly composite, but they also increase the amount of CO combustion aid added. Although subsequent bifunctional metal passivators have made many improvements and selected rare earth metals or alkali metals as vanadium passivators, the nickel passivation component is still mostly an antimony-based passivator, and most of them still select a separate nickel passivation agent and a vanadium passivation agent for compounding. The preparation method is cumbersome and the failure rate is high. CN107159315A selects antimony as the nickel passivation agent and the rare earth element lanthanum as the vanadium passivation agent to prepare a bifunctional metal passivator. CN102974400A compounds a single antimony agent and a single cerium agent to obtain a bifunctional metal passivator. CN104841490A uses one or both of antimony trioxide and antimony pentoxide as nickel passivation agents and lanthanum acetate as vanadium passivation agent to prepare a dual-function metal passivator.

[0006] Prior research has also explored bifunctional metal passivators in non-antimony and non-tin systems, primarily using the non-metallic element boron to replace antimony and tin. However, their synthesis is complex, and due to the use of non-metallic elements, their passivation capacity needs to be improved. CN102974401A uses boron and magnesium as the main active components to prepare an environmentally friendly, multifunctional metal passivator primarily used to inhibit nickel and vanadium contamination in catalytic cracking processes.

[0007] In addition, the above-mentioned metal passivators can only passivate nickel and vanadium pollution, cannot inhibit calcium pollution, and do not have the function of enhancing the catalytic cracking catalyst.

[0008] Therefore, existing catalytic cracking passivators have technical problems such as high toxicity, high cost, difficulty in preparation, poor stability, and single function.

[0009] In summary, in order to replace the traditional catalytic cracking metal passivators, the development of a new type of catalytic cracking multifunctional additive has become one of the urgent problems to be solved in this field.

[0010] Summary of the Invention

[0011] To address the above technical problems, the present invention provides a multifunctional catalytic cracking additive and a method for preparing the same. The multifunctional catalytic cracking additive provided by the present invention can inhibit contamination by metals such as nickel, vanadium, and calcium during the catalytic cracking process and can also synergize with the catalyst, providing a synergistic effect.

[0012] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a multifunctional additive for catalytic cracking, which comprises the following raw materials, in terms of mass percentage: 8% to 30% of a first ligand, 5% to 30% of a second ligand, 5% to 25% of a solubilizer, 10% to 25% of a metal component and 5% to 30% of water; wherein the first ligand comprises an alcohol compound, the second ligand comprises an ester compound, and the metal component comprises three or more of magnesium, aluminum, cerium, lanthanum, praseodymium, zirconium and yttrium.

[0013] According to a specific embodiment of the present invention, preferably, the catalytic cracking multifunctional additive includes the following raw materials, calculated by mass percentage: 10% to 25% of the first ligand, 10% to 25% of the second ligand, 10% to 20% of the solubilizer, 12% to 20% of the metal component and 10% to 25% of water.

[0014] In the above-mentioned multifunctional additive for catalytic cracking, preferably, the first ligand includes ethylene glycol and / or glycerol.

[0015] In the above-mentioned multifunctional additive for catalytic cracking, preferably, the second ligand includes butyl acetate and / or propyl acetate.

[0016] In the above-mentioned multifunctional additive for catalytic cracking, preferably, the solubilizer comprises an amide compound, more preferably, the solubilizer comprises one or a combination of N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide.

[0017] In the above-mentioned multifunctional additive for catalytic cracking, preferably, the metal component includes lanthanum, and two or more of magnesium, aluminum, cerium, praseodymium, zirconium and yttrium.

[0018] In the above-mentioned catalytic cracking multifunctional auxiliary agent, preferably, in terms of mass percentage, the content of lanthanum in the raw material of the catalytic cracking multifunctional auxiliary agent is 2% to 15% (more preferably 5% to 10%), the content of cerium is 0% to 10% (more preferably 1% to 5%), the content of aluminum is 0% to 10% (more preferably 1% to 5%), the content of magnesium is 0% to 10% (more preferably 1% to 5%), the content of praseodymium is 0% to 10% (more preferably 1% to 8%), the content of zirconium is 0% to 10% (more preferably 1% to 8%), the content of yttrium is 0% to 10% (more preferably 1% to 8%), and the content of two or more elements among magnesium, aluminum, cerium, praseodymium, zirconium and yttrium is not 0%, and the total content of metal components is 10% to 25% (more preferably 12% to 20%).

[0019] According to a specific embodiment of the present invention, preferably, the catalytic cracking multifunctional additive is prepared by at least the following steps:

[0020] (1) adding a first ligand dropwise to a solution of a metal component precursor while stirring, and reacting for a period of time to obtain a first solution;

[0021] (2) adding the second ligand dropwise to the first solution while stirring, and reacting for a period of time to obtain a second solution;

[0022] (3) adding the solubilizing agent dropwise to the second solution while stirring for a period of time to form a uniform and stable system, thereby obtaining the multifunctional catalytic cracking additive.

[0023] In the above-mentioned multifunctional additive for catalytic cracking, preferably, in the preparation step of the multifunctional additive for catalytic cracking, the precursor of the metal component in step (1) includes a soluble salt compound of the metal component, more preferably a nitrate.

[0024] In the above-mentioned multifunctional catalytic cracking additive, preferably, in the preparation step of the multifunctional catalytic cracking additive, the solution of the metal component precursor in step (1) is obtained by mixing the metal component precursor with water. More preferably, the mixing temperature is 10°C to 30°C, and further preferably 15°C to 25°C. The mixing step can be carried out under stirring conditions.

[0025] In the above-mentioned multifunctional additive for catalytic cracking, preferably, in the preparation step of the multifunctional additive for catalytic cracking, the dripping speed of the first ligand in step (1) is 1 to 10 drops / 10s, more preferably 2 to 8 drops / 10s.

[0026] In the above-mentioned multifunctional catalytic cracking additive, preferably, in the preparation step of the multifunctional catalytic cracking additive, the reaction temperature in step (1) is 40°C to 80°C, and the reaction time is 2h to 5h. More preferably, the reaction temperature in step (1) is 45°C to 70°C, and the reaction time is 2h to 4h.

[0027] In the above-mentioned multifunctional additive for catalytic cracking, preferably, in the preparation step of the multifunctional additive for catalytic cracking, the dripping speed of the second ligand in step (2) is 1 to 20 drops / 10s, more preferably 1 to 10 drops / 10s.

[0028] In the above-mentioned multifunctional catalytic cracking additive, preferably, in the preparation step of the multifunctional catalytic cracking additive, the reaction temperature in step (2) is 80°C to 120°C, and the reaction time is 1 hour to 3 hours. More preferably, the reaction temperature in step (2) is 90°C to 110°C, and the reaction time is 1 hour to 2 hours.

[0029] In the above-mentioned multifunctional catalytic cracking additive, preferably, in the preparation step of the multifunctional catalytic cracking additive, the stirring temperature in step (3) is 80°C to 120°C, and the time is 0.5h to 2h. More preferably, the stirring temperature in step (3) is 90°C to 110°C, and the time is 0.5h to 1.5h.

[0030] According to a specific embodiment of the present invention, preferably, the density of the catalytic cracking multifunctional additive at 20°C is 1.00 g·cm -3 ~2.00g·cm -3 , more preferably 1.15 g·cm -3 ~1.85g·cm -3 The density of the catalytic cracking multifunctional additive is obtained by testing in accordance with GB / 4472-84.

[0031] According to a specific embodiment of the present invention, preferably, the kinematic viscosity of the catalytic cracking multifunctional additive at 20°C is 8.00 mm 2 ·s -1 ~18.00mm 2 ·s -1 , more preferably 10.00 mm 2 ·s -1 ~15.00mm 2 ·s -1 The kinematic viscosity of the catalytic cracking multifunctional additive is obtained by testing in accordance with GB / T265-88.

[0032] The second aspect of the present invention provides a method for preparing the above-mentioned catalytic cracking multifunctional additive, which comprises the following steps:

[0033] (1) adding a first ligand dropwise to a solution of the metal component precursor while stirring, and reacting for a period of time to obtain a first solution;

[0034] (2) adding the second ligand dropwise to the first solution while stirring, and reacting for a period of time to obtain a second solution;

[0035] (3) adding the solubilizing agent dropwise to the second solution while stirring for a period of time to form a uniform and stable system, thereby obtaining the multifunctional additive for catalytic cracking.

[0036] In the above-mentioned preparation method of the present invention, first, the first ligand in step (1) is coordinated with the precursor of the metal component to obtain a solution (i.e., the first solution) containing the complex of the metal component and the first ligand; then, the second ligand in step (2) is further subjected to a coupling reaction with the complex formed in step (1), and the solubilizer in step (3) is used, which mainly plays the role of promoting the further coupling reaction between the second ligand and the complex formed in step (1), and also has the role of strengthening dispersion and enhancing solubility, thereby forming a final metal complex and obtaining the multifunctional additive for catalytic cracking of the present invention.

[0037] In the above preparation method, preferably, the precursor of the metal component in step (1) includes a soluble salt compound of the metal component, more preferably a nitrate.

[0038] In the above-mentioned preparation method, preferably, the solution of the metal component precursor in step (1) is obtained by mixing the metal component precursor with water. More preferably, the mixing temperature is 10°C to 30°C, and further preferably 15°C to 25°C. The mixing step can be carried out under stirring conditions.

[0039] In the above preparation method, preferably, the dropping speed of the first ligand in step (1) is 1 to 10 drops / 10s, more preferably 2 to 8 drops / 10s.

[0040] In the above preparation method, preferably, the reaction temperature in step (1) is 40°C to 80°C, and the reaction time is 2h to 5h. More preferably, the reaction temperature in step (1) is 45°C to 70°C, and the reaction time is 2h to 4h.

[0041] In the above preparation method, preferably, the dropping speed of the second ligand in step (2) is 1 to 20 drops / 10s, more preferably 1 to 10 drops / 10s.

[0042] In the above preparation method, preferably, the reaction temperature in step (2) is 80°C to 120°C, and the reaction time is 1 hour to 3 hours. More preferably, the reaction temperature in step (2) is 90°C to 110°C, and the reaction time is 1 hour to 2 hours.

[0043] In the above preparation method, preferably, the stirring temperature in step (3) is 80°C to 120°C, and the time is 0.5h to 2h. More preferably, the stirring temperature in step (3) is 90°C to 110°C, and the time is 0.5h to 1.5h.

[0044] The present invention provides a catalytic cracking multifunctional auxiliary agent and a preparation method thereof. The present invention adopts a metal component that meets environmental protection requirements, uses an alcohol compound as a first ligand, an ester compound as a second ligand, and an amide compound as a solubilizer, and prepares a catalytic cracking multifunctional auxiliary agent through a coordination reaction. The preparation method of the multifunctional auxiliary agent of the present invention avoids the compounding method of conventional multifunctional metal passivators, and the preparation process has low energy consumption and is easy to operate. At the same time, the catalytic cracking multifunctional auxiliary agent obtained by the preparation method of the present invention and the ratio and content of each raw material has stable performance, can inhibit the pollution of metals such as nickel, vanadium, and calcium during the catalytic cracking process, and can synergistically act with the catalyst to have a synergistic function on the catalyst. The catalytic cracking multifunctional auxiliary agent provided by the present invention is suitable for oil refining catalytic cracking units.

[0045] The components of the catalytic cracking multifunctional auxiliary agent provided by the present invention are safe and environmentally friendly, and because of certain advancements in component selection, its mechanism for suppressing metal pollution is different from that of traditional antimony and tin-based metal passivators. The metal component used in the present invention is combined with the first ligand and the second ligand to make its capture power for Ni and V substances in the crude oil stronger, while enhancing the solubility of the multifunctional auxiliary agent of the present invention in the crude oil and the reaction performance of the auxiliary agent. Therefore, the multifunctional auxiliary agent of the present invention has an excellent effect of suppressing Ni and V pollution, which is better than traditional antimony and tin-based metal passivators. In addition, the multifunctional auxiliary agent of the present invention can also suppress Ca pollution. At the same time, the multifunctional auxiliary agent and the catalytic cracking catalyst produce a synergistic effect, promote catalyst activity, improve product distribution, and increase total liquid yield. The catalytic cracking multifunctional auxiliary agent of the present invention can meet the smooth operation and cost reduction and efficiency improvement requirements of the catalytic cracking unit of the refining enterprise.

[0046] The technical solution of the present invention has at least the following beneficial effects:

[0047] 1. The multifunctional catalytic cracking additive of the present invention is safe and environmentally friendly. Currently, the most widely used antimony- and tin-based metal passivators against Ni and V are highly toxic, and the use of antimony poses environmental and safety concerns. The multifunctional catalytic cracking additive of the present invention, however, utilizes environmentally friendly metal elements as active components, ensuring safe production for enterprises and resolving the need for environmentally friendly disposal of subsequent catalysts.

[0048] 2. The multifunctional catalytic cracking additive of the present invention exhibits excellent performance in inhibiting Ni, V, and Ca contamination. Due to its good oil solubility and the use of an organic ligand, it has a stronger ability to capture Ni and V in the feedstock oil. Compared to the absence of the multifunctional catalytic cracking additive, the use of this additive reduces the coke yield by an average of more than 0.7% and the dry gas yield by an average of more than 0.2%, outperforming most currently commercially available antimony and tin-based liquid metal passivators.

[0049] 3. The multifunctional catalytic cracking additive of the present invention effectively improves the distribution of catalytic cracking products and increases total liquid yield. This additive can synergize with the catalyst to promote catalyst activity, improve product distribution, and increase total liquid yield, which is crucial for enterprises to reduce costs and increase efficiency.

[0050] In summary, the multifunctional catalytic cracking additive provided by the present invention meets environmental protection requirements, can inhibit metal pollution, and has an efficiency-enhancing function. It also has the advantages of low cost, simple preparation, stable performance and high efficiency, and can meet the needs of refining and chemical enterprises. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0052] In the following examples and comparative examples, the performance of the catalytic cracking multifunctional additive was evaluated in the following manner:

[0053] Evaluation device: XTL-5 riser reactor;

[0054] The raw material for the reaction is the feedstock oil of the 3 million t / a heavy oil catalytic cracking unit of PetroChina Lanzhou Petrochemical Company. The main properties of the raw material are: relative molecular mass 426 g / mol, density (70℃) 890.6 kg / m 3 , residual carbon mass fraction is 3.4%, V content is 5.13μg / g, Fe content is 6.83μg / g, Ca content is 4.36μg / g, Cu content is 0.35μg / g, Ni content is 4.35μg / g, Pb content is less than 0.02μg / g, saturated hydrocarbon mass fraction is 58.4%, aromatic hydrocarbon mass fraction is 37.2%, and colloid mass fraction is 4.4%;

[0055] The catalyst used is LDO-75, produced by PetroChina Lanzhou Petrochemical Company;

[0056] The specific evaluation conditions are as follows: reaction pressure: atmospheric pressure; reaction temperature: 500°C (riser outlet); regeneration temperature: 690°C; oil feed rate: 1.2 kg / h; catalyst-oil ratio: 5-6.5; reaction time: 1.69 s;

[0057] The evaluation experiment adopted a one-time filling method, mixing the catalytic cracking multifunctional additive with the feed oil evenly, and then continuously injecting the samples into the device together; the addition amount of the catalytic cracking multifunctional additive was 150ppm;

[0058] The gas and liquid compositions of catalytic cracking products were analyzed using SQ-206 gas chromatography.

[0059] Example 1

[0060] This embodiment provides a multifunctional catalytic cracking additive, which is prepared by the following steps:

[0061] (1) 56.5 g of aluminum nitrate nonahydrate, 35 g of cerium nitrate hexahydrate, and 78.5 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis device, 50 ml of distilled water was slowly added, and the mixture was stirred and mixed at 10° C. to obtain a solution of a metal component precursor;

[0062] (2) slowly adding 41 g of ethylene glycol to the solution of the metal component precursor at a rate of 1 drop / 10 s, heating the solution to 40° C. while stirring, and reacting for 2 h to obtain a first solution;

[0063] (3) 46 g of butyl acetate was slowly added to the first solution at a rate of 1 drop / 10 s while stirring, and the temperature was raised to 80° C. for 1 h to obtain a second solution;

[0064] (4) 44 ml of N,N-dimethylformamide was added dropwise to the second solution, the temperature was maintained at 80° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the multifunctional catalytic cracking additive.

[0065] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 1.

[0066] When the catalytic cracking multifunctional additive prepared in this example was added to the crude oil, after running in the catalytic cracking riser reactor for 18 hours, the coke yield decreased by 0.43%, the dry gas yield decreased by 0.16%, and the total liquid yield increased by 0.42%, demonstrating excellent metal contamination inhibition and catalyst efficiency enhancement performance.

[0067] Example 2

[0068] This embodiment provides a multifunctional catalytic cracking additive, which is prepared by the following steps:

[0069] (1) 58 g of aluminum nitrate nonahydrate, 38 g of magnesium nitrate, 86.6 g of lanthanum nitrate hexahydrate, and 29 g of yttrium nitrate were placed in a normal pressure reaction synthesis apparatus, 50 ml of distilled water was slowly added, and the mixture was stirred and mixed at 25° C. to obtain a solution of a metal component precursor;

[0070] (2) slowly adding 45 g of a mixture of ethylene glycol and glycerol (the molar ratio of ethylene glycol to glycerol is 3:2) to the solution of the metal component precursor at a rate of 5 drops / 10 s, heating the mixture to 50° C. while stirring, and reacting for 3 h to obtain a first solution;

[0071] (3) 52 g of a mixture of butyl acetate and propyl acetate (the molar ratio of butyl acetate to propyl acetate is 1:1) was slowly added dropwise to the first solution at a rate of 10 drops / 10 s while stirring, and the temperature was raised to 110° C. and reacted for 2 h to obtain a second solution;

[0072] (4) 42 ml of N,N-dimethylformamide was added dropwise to the second solution, the temperature was maintained at 110° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the catalytic cracking multifunctional additive.

[0073] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 1.

[0074] When the catalytic cracking multifunctional additive prepared in this example was added to the crude oil, after 18 hours of operation in the catalytic cracking riser reactor, the coke yield decreased by 1.06%, the dry gas yield decreased by 0.41%, and the total liquid yield increased by 2.05%, demonstrating excellent metal contamination inhibition and catalyst efficiency enhancement performance.

[0075] Example 3

[0076] This embodiment provides a multifunctional catalytic cracking additive, which is prepared by the following steps:

[0077] (1) 44 g of cerium nitrate hexahydrate, 34 g of zirconium nitrate pentahydrate, and 65 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis apparatus, 50 ml of distilled water was slowly added, and the mixture was stirred and mixed at 30° C. to obtain a solution of a metal component precursor;

[0078] (2) slowly adding 35 g of ethylene glycol to the solution of the metal component precursor at a rate of 10 drops / 10 s, heating the solution to 50° C. while stirring, and reacting for 5 h to obtain a first solution;

[0079] (3) 38 g of propyl acetate was slowly added to the first solution at a rate of 20 drops / 10 s while stirring, and the temperature was raised to 90° C. for reaction for 3 h to obtain a second solution;

[0080] (4) 32 ml of N,N-dimethylformamide was added dropwise to the second solution, and the temperature was maintained at 100° C. and stirred for 2 h to form a uniform and stable system, thereby obtaining the multifunctional catalytic cracking additive.

[0081] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 1.

[0082] When the catalytic cracking multifunctional additive prepared in this example was added to the crude oil, after 18 hours of operation in the catalytic cracking riser reactor, the coke yield decreased by 0.65%, the dry gas yield decreased by 0.27%, and the total liquid yield increased by 1.11%, demonstrating excellent metal contamination inhibition and catalyst efficiency enhancement performance.

[0083] Example 4

[0084] This embodiment provides a multifunctional catalytic cracking additive, which is prepared by the following steps:

[0085] (1) 30 g of magnesium nitrate, 44 g of praseodymium nitrate hexahydrate, and 53 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis device, 35 ml of distilled water was slowly added, and the mixture was stirred and mixed at 20° C. to obtain a solution of a metal component precursor;

[0086] (2) slowly adding 30 g of a mixture of ethylene glycol and glycerol (the molar ratio of ethylene glycol to glycerol is 1:1) to the solution of the metal component precursor at a rate of 5 drops / 10 s, heating the mixture to 60° C. while stirring, and reacting for 2 h to obtain a first solution;

[0087] (3) 36 g of a mixture of butyl acetate and propyl acetate (the molar ratio of butyl acetate to propyl acetate is 1:1) was slowly added dropwise to the first solution at a rate of 10 drops / 10 s while stirring, and the temperature was raised to 110° C. and reacted for 2 h to obtain a second solution;

[0088] (4) 30 ml of N,N-dimethylacetamide was added dropwise to the second solution, the temperature was maintained at 110° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the multifunctional additive for catalytic cracking.

[0089] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 1.

[0090] When the catalytic cracking multifunctional additive prepared in this example was added to the crude oil, after 18 hours of operation in the catalytic cracking riser reactor, the coke yield decreased by 0.82%, the dry gas yield decreased by 0.34%, and the total liquid yield increased by 1.52%, demonstrating excellent metal contamination inhibition and catalyst efficiency enhancement performance.

[0091] Example 5

[0092] This embodiment provides a multifunctional catalytic cracking additive, which is prepared by the following steps:

[0093] (1) 75 g of aluminum nitrate nonahydrate, 43 g of zirconium nitrate pentahydrate, and 65 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis apparatus, 40 ml of distilled water was slowly added, and the mixture was stirred and mixed at 20° C. to obtain a solution of a metal component precursor;

[0094] (2) slowly adding 30 g of a mixture of ethylene glycol and glycerol (the molar ratio of ethylene glycol to glycerol is 1:2) to the solution of the metal component precursor at a rate of 10 drops / 10 s, heating the mixture to 80° C. while stirring, and reacting for 2 h to obtain a first solution;

[0095] (3) 48 g of butyl acetate was slowly added to the first solution at a rate of 15 drops / 10 s while stirring, and the temperature was raised to 120° C. for 1 h to obtain a second solution;

[0096] (4) 37 ml of N-methylformamide was added dropwise to the second solution, the temperature was maintained at 120° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the multifunctional catalytic cracking additive.

[0097] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 1.

[0098] When the catalytic cracking multifunctional additive prepared in this example was added to the crude oil, after 18 hours of operation in the catalytic cracking riser reactor, the coke yield decreased by 0.57%, the dry gas yield decreased by 0.26%, and the total liquid yield increased by 1.25%, demonstrating excellent metal contamination inhibition and catalyst efficiency enhancement performance.

[0099] Table 1 Physicochemical properties of the catalytic cracking multifunctional additives prepared in Examples 1 to 5

[0100] Comparative Example 1

[0101] This comparative example provides a catalytic cracking multifunctional additive, which is prepared by the following steps:

[0102] (1) 30 g of magnesium nitrate, 44 g of praseodymium nitrate hexahydrate, and 53 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis device, 35 ml of distilled water was slowly added, and the mixture was stirred and mixed at 20° C. to obtain a solution of a metal component precursor;

[0103] (2) slowly adding 58 g of a mixture of butyl acetate and propyl acetate (the molar ratio of butyl acetate to propyl acetate is 1:1) to the solution of the metal component precursor at a rate of 10 drops / 10 s while stirring, heating to 110° C. and reacting for 2 h to obtain a mixed solution;

[0104] (3) 30 ml of N,N-dimethylacetamide was added dropwise to the mixed solution, and the temperature was maintained at 110° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the catalytic cracking multifunctional additive.

[0105] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 2.

[0106] When the multifunctional catalytic cracking additive prepared in this comparative example was added to the feedstock oil, after 18 hours of operation in a catalytic cracking riser reactor, the coke yield increased by 0.16%, the dry gas yield increased by 0.21%, and the total liquid yield decreased by 0.34%. The reason for the poor performance of the additive in this comparative example is speculated to be that the first ligand was not used. Despite increasing the amount of the second ligand, the metal components were unable to form a complex well, and the uncoordinated metal ions agglomerated on the catalyst surface, which in turn affected the performance of the catalyst.

[0107] Comparative Example 2

[0108] This comparative example provides a catalytic cracking multifunctional additive, which is prepared by the following steps:

[0109] (1) 30 g of magnesium nitrate, 44 g of praseodymium nitrate hexahydrate, and 53 g of lanthanum nitrate hexahydrate were placed in a normal pressure reaction synthesis device, 35 ml of distilled water was slowly added, and the mixture was stirred and mixed at 20° C. to obtain a solution of a metal component precursor;

[0110] (2) slowly adding 30 g of a mixture of ethylene glycol and glycerol (the molar ratio of ethylene glycol to glycerol is 1:1) to the solution of the metal component precursor at a rate of 5 drops / 10 s, heating the mixture to 60° C. while stirring, and reacting for 2 h to obtain a first solution;

[0111] (3) 30 ml of N,N-dimethylacetamide was added dropwise to the first solution, and the temperature was raised to 110° C. and stirred for 0.5 h to form a uniform and stable system, thereby obtaining the catalytic cracking multifunctional additive.

[0112] The physical and chemical properties of the catalytic cracking multifunctional additive are shown in Table 2.

[0113] When the multifunctional catalytic cracking additive prepared in this comparative example was added to a feedstock oil, after 18 hours of operation in a catalytic cracking riser reactor, the coke yield remained essentially unchanged, the dry gas yield decreased by 0.10%, and the total liquid yield increased by 0.16%. The poor performance of the additive in this comparative example is presumably due to the lack of a secondary ligand. The complex formed by the metal component and the primary ligand is relatively small, resulting in a tendency to aggregate on the catalyst surface, hindering the effective component from performing its function.

[0114] Table 2 Physicochemical properties of the catalytic cracking multifunctional additives prepared in Comparative Examples 1 and 2

[0115] In summary, the multifunctional catalytic cracking additive provided by the present invention meets environmental protection requirements, can inhibit metal pollution, and has the function of enhancing the efficiency of the catalyst. It also has the advantages of low cost, simple preparation, stable performance and high efficiency, and can meet the needs of refining and chemical enterprises.

Claims

1. A multifunctional catalytic cracking additive, which comprises the following raw materials, by mass percentage: 8% to 30% of a first ligand, 5% to 30% of a second ligand, 5% to 25% of a solubilizer, 10% to 25% of a metal component and 5% to 30% of water; wherein: The first ligand includes an alcohol compound, the second ligand includes an ester compound, and the metal component includes three or more of magnesium, aluminum, cerium, lanthanum, praseodymium, zirconium and yttrium.

2. The multifunctional additive for catalytic cracking according to claim 1, wherein: The catalytic cracking multifunctional additive comprises the following raw materials in terms of mass percentage: The first ligand comprises 10% to 25%, the second ligand comprises 10% to 25%, the solubilizing agent comprises 10% to 20%, the metal component comprises 12% to 20% and the water comprises 10% to 25%.

3. The multifunctional additive for catalytic cracking according to claim 1, wherein: The first ligand includes ethylene glycol and / or glycerol.

4. The multifunctional additive for catalytic cracking according to claim 1, wherein The second ligand includes butyl acetate and / or propyl acetate.

5. The multifunctional additive for catalytic cracking according to claim 1, wherein The solubilizing agent includes an amide compound.

6. The multifunctional additive for catalytic cracking according to claim 5, wherein: The solubilizing agent includes one or a combination of N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide.

7. The multifunctional additive for catalytic cracking according to claim 1, wherein: The metal component includes lanthanum and two or more of magnesium, aluminum, cerium, praseodymium, zirconium and yttrium.

8. The multifunctional additive for catalytic cracking according to claim 7, wherein: In terms of mass percentage, the raw material of the catalytic cracking multifunctional additive contains 2% to 15% lanthanum, 0% to 10% cerium, 0% to 10% aluminum, 0% to 10% magnesium, 0% to 10% praseodymium, 0% to 10% zirconium, 0% to 10% yttrium, and the content of two or more elements among magnesium, aluminum, cerium, praseodymium, zirconium and yttrium is not 0%, and the total content of metal components is 10% to 25%.

9. The multifunctional additive for catalytic cracking according to claim 1, wherein: The density of the catalytic cracking multifunctional additive at 20°C is 1.00 g·cm -3 ~2.00g·cm -3 .

10. The multifunctional additive for catalytic cracking according to claim 9, wherein: The density of the catalytic cracking multifunctional additive at 20°C is 1.15 g·cm -3 ~1.85g·cm -3 .

11. The multifunctional additive for catalytic cracking according to claim 1, wherein: The kinematic viscosity of the catalytic cracking multifunctional additive at 20°C is 8.00 mm 2 ·s -1 ~18.00mm 2 ·s -1 .

12. The multifunctional additive for catalytic cracking according to claim 11, wherein: The kinematic viscosity of the catalytic cracking multifunctional additive at 20°C is 10.00 mm 2 ·s -1 ~15.00mm 2 ·s -1 .

13. The method for preparing the multifunctional additive for catalytic cracking according to claim 1, comprising the following steps: (1) adding a first ligand dropwise to a solution of a metal component precursor while stirring, and reacting for a period of time to obtain a first solution; (2) adding the second ligand dropwise to the first solution while stirring, and reacting for a period of time to obtain a second solution; (3) adding the solubilizing agent dropwise to the second solution and stirring for a period of time to form a uniform and stable system to obtain the multifunctional additive for catalytic cracking.

14. The preparation method according to claim 13, wherein: The precursor of the metal component in step (1) includes a soluble salt compound of the metal component.

15. The preparation method according to claim 13, wherein: In step (1), the dropping speed of the first ligand is 1 to 10 drops / 10s.

16. The preparation method according to claim 13, wherein: The reaction temperature in step (1) is 40°C to 80°C, and the reaction time is 2h to 5h.

17. The preparation method according to claim 13, wherein: In step (2), the dropping speed of the second ligand is 1 to 20 drops / 10s.

18. The preparation method according to claim 13, wherein: The reaction temperature in step (2) is 80°C to 120°C, and the reaction time is 1h to 3h.

19. The preparation method according to claim 13, wherein: The stirring temperature in step (3) is 80°C to 120°C, and the stirring time is 0.5h to 2h.

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