A method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst

Abstract

This invention provides a method for simulating the preparation of an industrial iron-contaminated catalytic cracking catalyst. Step 1 involves reacting a first feedstock with a fresh catalytic cracking catalyst, stripping to remove hydrocarbons, then performing coke burn regeneration, followed by stripping and cooling. The treated catalytic cracking catalyst is then recycled with the first feedstock for a cycle of reaction, stripping, regeneration, and stripping, repeated at least once. Step 2 involves reacting a second feedstock with the catalytic cracking catalyst obtained in Step 1, stripping to remove hydrocarbons, then performing coke burn regeneration, followed by stripping and cooling. The treated catalytic cracking catalyst is then recycled with the second feedstock for a cycle of reaction, stripping, regeneration, and stripping, repeated at least once. Step 3 involves subjecting the catalytic cracking catalyst obtained in Step 2 to hydrothermal aging treatment. The first feedstock contains alkali metal compounds, alkaline earth metal compounds, and / or transition metal compounds other than iron, while the second feedstock contains iron-containing compounds.

Description

Technical Field

[0001] This invention relates to a laboratory aging pretreatment method for fresh catalysts in the field of catalytic cracking, and more specifically, a method for simulating the preparation of industrial iron-contaminated catalytic cracking catalysts. Background Technology

[0002] In recent years, with the increasing weight and quality of crude oil worldwide, most refineries have begun developing catalytic cracking (FCC) technologies for blending or refining heavy oil and residue. The content of harmful metals in heavy oil or residue is far higher than that in distillate oils. Harmful metals such as iron, sodium, calcium, nickel, and vanadium, which exist in feedstock oils in the form of porphyrin compounds, naphthenates, and inorganic salts, are continuously deposited on the catalyst surface through long-term reaction processes in industrial plants. This poisoning occurs by disrupting the crystal structure, clogging pores, and covering active sites.

[0003] Heavy metal contamination by nickel and vanadium has long been a concern. Iron poisoning in catalytic cracking catalysts is also gradually gaining attention. Some refineries have already experienced iron poisoning in actual production. As iron contamination in catalytic cracking units worsens, industrial units mainly exhibit the following symptoms: increased slurry oil yield, decreased conversion rate, increased dry gas and hydrogen yield, and decreased gasoline and diesel yield. Furthermore, with increasing iron contamination on the catalyst, numerous nodular protrusions form on the catalyst surface, covering the catalyst's pores, leading to poor equilibrium catalyst fluidization properties and a decrease in apparent bulk density.

[0004] Therefore, it is necessary to develop catalytic cracking catalysts resistant to heavy metal iron contamination through laboratory research to address the increasingly serious trend of heavy metal iron contamination. While designing catalysts resistant to heavy metal iron contamination can be accomplished in the laboratory, how to achieve comprehensive simulation of iron contamination balancers from fresh catalysts to industrial plants through effective laboratory simulation methods has become an urgent issue. Simulation of iron contamination balancers includes not only simulating the iron loading and valence state on the catalyst, but more importantly, simulating the formation of iron nodules on the catalyst surface.

[0005] The Mitchell equal-volume impregnation method is a simple method for simulating the resistance of catalytic cracking catalysts to heavy metal contamination. Specifically, fresh catalyst is impregnated in the laboratory with an equal volume of a heavy metal compound solution. The catalyst is then uniformly dried by low-temperature calcination, followed by high-temperature calcination to remove dissolved heavy metals and heavy metal complexes, ultimately leaving only the heavy metals deposited on the catalyst. Finally, the catalyst undergoes hydrothermal aging to obtain the final aged catalyst. This method is simple to operate, but it also has the following shortcomings: (1) The heavy metal deposition achieved by the impregnation method is through the inside and outside of the catalyst and is uniformly distributed throughout the entire catalyst particle, rather than the distribution of heavy metal elements from the outside to the inside due to gradual deposition on the industrial equilibrium agent; (2) Since the impregnation method deposits heavy metal elements on the catalyst through high-temperature roasting in the air, heavy metals such as nickel, vanadium, and iron are all in the highest valence state, and it is impossible to simulate the valence state distribution of heavy metals on the equilibrium agent; (3) Since the impregnation method loads all metals onto the catalyst surface at once, it does not simulate the multiple cyclic reactions of industrial equipment. On the other hand, there is no environment on the catalyst that is conducive to the deposition of heavy metal iron, so it is difficult to simulate iron nodules on the catalyst surface by the impregnation method.

[0006] Albemarle has designed a CD (Cyclic Deactivation) cycle reactor to simulate the effects of heavy metal contamination on catalyst activity. It consists of a fixed-bed reactor, with a single charge of 100g–200g of catalyst. The catalyst is deactivated through repeated cycles of cracking, stripping, and regeneration. During the cracking stage, a VGO / VR feedstock mixed with organic heavy metals is used. After the reaction, stripping is performed with nitrogen or steam, and finally, stripping is done with steam / N2 / O2 and other substances (such as SO2). x A mixture of gases was regenerated at 788℃ for 30 minutes. The equilibrium agent was simulated through multiple cycles. This method can achieve the positional distribution of heavy metal iron on the catalyst, but it cannot achieve the valence state distribution of heavy metal iron in industrial catalysts. Furthermore, it is difficult to induce iron nodule growth on the catalyst surface.

[0007] Du Quansheng et al. (Petroleum Refining and Chemical Engineering, 2007.2) conducted SEM and EDS analyses on iron-contaminated balancers collected from industrial plants and iron-contaminated catalysts prepared in the laboratory. They found significant differences in the distribution of iron on the catalysts from different iron sources. The laboratory-prepared iron-contaminated catalysts used ferric chloride and ferric naphthenate as iron sources, prepared via impregnation and cyclic contamination methods, respectively. The paper used high-resolution scanning electron microscopy to observe the iron-contaminated catalysts collected from industrial plants, revealing obvious iron nodules on their surface. However, nodules were not observed on the artificially contaminated catalysts in the laboratory; only EDS analysis showed that when ferric naphthenate was deposited on the catalyst via cyclic loading, it mainly existed on the outer layer of the catalyst particles.

[0008] Liu Qianqian et al. (Petroleum Refining and Chemical Engineering, 2018.5) utilized the cyclic contamination function of the ACE-D100 unit to contaminate the catalyst with metals in six batches. After repeated reactions, stripping, and regeneration to achieve the target average metal contamination level, the catalyst was removed and subjected to a certain number of cycles of redox hydrothermal post-treatment to finally obtain a laboratory aging agent. The problem with this method is that it divides the catalyst aging process in the industrial unit into two separate stages: first, heavy metal loading is achieved through multiple reaction-regeneration cycles, and then the hydrothermal aging post-treatment is completed. The disadvantage of this method is that it does not simulate the continuous heavy metal contamination and hydrothermal aging process in an industrial unit. The separate metal loading and hydrothermal aging processes prevent continuous operation of the unit, resulting in a long catalyst treatment cycle. Furthermore, the catalyst undergoes a redox cycle at a temperature of 780°C. The atmosphere changes for one redox cycle are as follows: 10 min nitrogen stripping, 10 min oxidizing gas treatment, 10 min nitrogen stripping, and 10 min reducing gas treatment. Water vapor with a volume fraction of 60% is present in all four steps. This ultimately yields a laboratory aging agent. This method is similar to the CPS aging method developed by Grace Davison. Its drawback is that although a redox cycle is performed, oxidation is the first step in each cycle. This causes the heavy metals on the catalyst to undergo hydrothermal aging in a high valence state, exacerbating the destructive effect of the same amount of heavy metals nickel and vanadium on the catalyst, reducing the catalyst's thermal stability, and easily leading to catalyst particle sintering.

[0009] In summary, although existing technologies have conducted laboratory simulation studies of iron contamination on fresh catalysts through various methods, the catalysts obtained by these methods do not possess the characteristics of the distribution location of heavy metal iron, the distribution of iron valence states, and the formation of iron nodules on the catalyst surface of industrial iron contamination balancers. Therefore, it is difficult to accurately evaluate the performance of the prepared anti-metal catalytic cracking catalysts. Summary of the Invention

[0010] The main objective of this invention is to provide a method for simulating the preparation of industrial iron-contaminated catalytic cracking catalysts. In the catalyst obtained by the method of this invention, the distribution position and valence state of iron are similar to those of industrial iron-contaminated equilibrium agents, which can provide strong support for practical industrial applications.

[0011] To achieve the above objectives, the present invention provides a method for simulating the preparation of an industrial iron-contaminated catalytic cracking catalyst, comprising the following steps:

[0012] Step 1: React the first feedstock oil with fresh catalytic cracking catalyst, then strip to remove hydrocarbon oil and gas, then regenerate by coking, then strip to cool, and then cycle the treated catalytic cracking catalyst with the first feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one.

[0013] Step 2: React the second feedstock oil with the catalytic cracking catalyst obtained in Step 1, then strip to remove hydrocarbon oil and gas, then perform coke burning regeneration, then strip to cool down, and then cycle the treated catalytic cracking catalyst with the second feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one.

[0014] Step 3: Perform hydrothermal aging treatment on the catalytic cracking catalyst obtained in Step 2 to obtain an industrial iron-contaminated catalytic cracking catalyst.

[0015] The first feedstock oil contains alkali metal compounds, alkaline earth metal compounds, and / or transition metal compounds other than iron, while the second feedstock oil contains iron-containing compounds.

[0016] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention includes the following: the alkali metal compound is a sodium-containing organic compound; the alkaline earth metal compound is a calcium-containing organic compound; the transition metal compound other than iron is at least one of nickel-containing organic compounds, vanadium-containing organic compounds, and copper-containing organic compounds; and the iron-containing compound is an iron-containing organic compound.

[0017] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention, wherein the alkali metal compound is sodium isooctanoate and / or sodium naphthenate, the alkaline earth metal compound is calcium stearate, and the transition metal compound other than iron is nickel naphthenate, vanadium naphthenate, or copper naphthenate; and the iron-containing compound is at least one of ferric naphthenate, ferric stearate, and ferrocene.

[0018] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention, wherein the metal concentration in the first feed oil is 100 μg / g to 2000 μg / g (calculated as metal); and the metal concentration in the second feed oil is 100 μg / g to 2000 μg / g (calculated as metal).

[0019] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention comprises the following steps: a first feedstock oil is preheated and reacted with a fresh catalytic cracking catalyst at a preheating temperature of 60℃~90℃, a reaction temperature of 490℃~530℃, a catalyst-to-oil ratio of 5~30, a single-cycle oil feeding time of 1min~5min, and a mass flow rate of the first feedstock oil of 5g / min~15g / min; a second feedstock oil is preheated and reacted with the catalytic cracking catalyst obtained in step 1 at a preheating temperature of 60℃~90℃, a reaction temperature of 490℃~530℃, a catalyst-to-oil ratio of 5~30, a single-cycle oil feeding time of 1min~5min, and a mass flow rate of the first feedstock oil of 5g / min~15g / min.

[0020] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention includes the following steps: In step 1, the stripping removal of hydrocarbon oil and gas and the stripping cooling are both carried out under the action of nitrogen gas, with a nitrogen flow rate of 500 ml / min to 1500 ml / min and a nitrogen stripping time of 1 min to 10 min; the coke regeneration temperature is 680℃ to 740℃ and the coke regeneration time is 20 min to 40 min.

[0021] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention, wherein in step 2, the stripping removal of hydrocarbon oil and gas and the stripping cooling are both carried out under the action of nitrogen, the nitrogen flow rate is 500 ml / min to 1500 ml / min, and the nitrogen stripping time is 1 min to 10 min; the coke regeneration temperature is 680℃ to 740℃, and the coke regeneration time is 20 min to 40 min.

[0022] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention, wherein step 3, hydrothermal aging treatment, includes:

[0023] The catalytic cracking catalyst obtained in step 2 is treated with a reducing gas, then with nitrogen, then with an oxidizing gas, and then with nitrogen again. This process of treating with a reducing gas, nitrogen, oxidizing gas, and nitrogen is repeated at least once to obtain an industrial iron-contaminated catalytic cracking catalyst.

[0024] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention, wherein, in step 2, a certain amount of water vapor is introduced into the catalytic cracking catalyst during treatment with reducing gas, nitrogen, and oxidizing gas, and the mass ratio of water vapor to reducing gas, water vapor to nitrogen, and water vapor to oxidizing gas is 30:70-55:45; the oxidizing gas includes one or more of high-purity air, oxygen in nitrogen, and sulfur dioxide in nitrogen; the selected reducing gas includes one or more of hydrogen in nitrogen, propylene in nitrogen, and carbon monoxide in nitrogen; The reducing gas is treated at a temperature of 700℃~770℃ for 2min~7min, with a flow rate of 500ml / min~1500ml / min; the nitrogen is treated at a temperature of 700℃~770℃ for 1min~10min, with a flow rate of 500ml / min~1500ml / min; the oxidizing gas is treated at a temperature of 700℃~770℃ for 2min~7min, with a flow rate of 500ml / min~1500ml / min.

[0025] The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to the present invention includes the following steps: step 1 is repeated 10 to 40 times, step 2 is repeated 100 to 300 times, and step 3 is repeated 75 to 120 times.

[0026] The beneficial effects of this invention are:

[0027] (1) The present invention uses a two-cycle aging metal loading method. The first step is to cycle-load alkali metals, alkaline earth metals or transition metals other than iron, and the second step is to load iron metals. The loading of metals in the first step can create a favorable environment for the loading of heavy metal iron on the catalyst surface.

[0028] (2) Furthermore, in the second step of heavy metal iron cyclic loading, the present invention uses a small amount of multiple cyclic loading mode. Each cycle loads a low amount of organometallic iron, and through multiple cycles, the organometallic iron can be gradually deposited on the catalyst surface to generate iron nodules similar to those on industrial balance agents, thus simulating the distribution state of organometallic iron on industrial balance agents. Attached Figure Description

[0029] Figure 1 The image shown is an electron microscope image of the LDR-600SR industrial balancing agent of Comparative Example 1 of this invention.

[0030] Figure 2 Electron micrograph of the aging simulator of Example 1 of the present invention;

[0031] Figure 3 Electron micrograph of the aging simulator of Comparative Example 2 of this invention;

[0032] Figure 4 Electron micrograph of the aging simulator of Comparative Example 3 of this invention;

[0033] Figure 5 Electron micrograph of the aging simulator of Comparative Example 4 of this invention;

[0034] Figure 6 Electron micrograph of the aging simulator of Comparative Example 5 of this invention;

[0035] Figure 7 Electron micrograph of the aging simulator of Comparative Example 6 of this invention;

[0036] Figure 8 The image shown is an electron microscope image of the aging simulator of Comparative Example 7 of this invention. Detailed Implementation

[0037] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0038] This invention provides a method for simulating the preparation of an industrial iron-contaminated catalytic cracking catalyst, comprising the following steps:

[0039] Step 1: React the first feedstock oil with fresh catalytic cracking catalyst, then strip to remove hydrocarbon oil and gas, then regenerate by coking, then strip to cool, and then cycle the treated catalytic cracking catalyst with the first feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one.

[0040] Step 2: React the second feedstock oil with the catalytic cracking catalyst obtained in Step 1, then strip to remove hydrocarbon oil and gas, then perform coke burning regeneration, then strip to cool down, and then cycle the treated catalytic cracking catalyst with the second feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one.

[0041] Step 3: Perform hydrothermal aging treatment on the catalytic cracking catalyst obtained in Step 2 to obtain an industrial iron-contaminated catalytic cracking catalyst.

[0042] The first feedstock oil contains alkali metal compounds, alkaline earth metal compounds, and / or transition metal compounds other than iron, while the second feedstock oil contains iron-containing compounds.

[0043] This invention employs a two-stage cyclic aging metal loading method. The first step involves cyclically loading alkali metals, alkaline earth metals, or transition metals other than iron. The second step involves loading iron metals. The metal loading in the first step creates a favorable environment for the loading of heavy metal iron onto the catalyst surface. The catalytic cracking catalyst obtained by this method exhibits similar properties to industrial iron-contaminated equilibrium catalysts and can be used to replace process iron-contaminated equilibrium catalysts in evaluation.

[0044] This invention does not limit the type of catalytic cracking catalyst used. Any commonly used catalytic cracking catalyst can be used. For example, the zeolite molecules are selected from one or more of REY, REX, REHY, USY, REUSY, HZSM-5, REZSM-5, REHZSM-5, and β-zeolite molecular sieves; the binder is selected from one or more of silica-alumina gel, silica sol, alumina sol, silica-alumina sol, boehmite, and pseudoboehmite; the clay material is selected from one or more of kaolin, hydrous kaolin, montmorillonite, diatomaceous earth, soapstone, attapulgite, sepiolite, attapulgite, hydrotalcite, and bentonite. Catalytic cracking catalysts made from the above raw materials can be treated using the method provided by this invention, and the treated catalyst can be a single catalyst or a mixture of two or more catalysts.

[0045] In this invention, the first feedstock contains alkali metal compounds, alkaline earth metal compounds, and / or transition metal compounds other than iron. The first feedstock can be one or more commonly used catalytic cracking feedstocks. For example, straight-run diesel, catalytic diesel, hydrotreated diesel, vacuum gas oil, atmospheric residue, coking gas oil, deasphalted oil, etc., preferably straight-run diesel, hydrotreated diesel, or mixtures thereof.

[0046] In one embodiment, the alkali metal compound is a sodium-containing organic compound, more specifically, an oil-soluble sodium-containing organic compound, such as sodium isooctanoate and / or sodium naphthenate; the alkaline earth metal compound is a calcium-containing organic compound, more specifically, an oil-soluble calcium-containing organic compound, such as calcium stearate; the transition metal compound other than iron is at least one of nickel-containing organic compounds, vanadium-containing organic compounds, and copper-containing organic compounds, more specifically, at least one of oil-soluble nickel-containing organic compounds, vanadium-containing organic compounds, and copper-containing organic compounds, such as nickel naphthenate, vanadium naphthenate, or copper naphthenate.

[0047] The amount of alkali metal compounds, alkaline earth metal compounds, and / or transition metal compounds other than iron added to the first feedstock is calculated based on the amount of fresh catalytic cracking catalyst added, the metal content of the target industrial equilibrium catalyst, the single-cycle feed time, the feed flow rate, and the total number of cycles. In one embodiment, the metal concentration in the first feedstock of the present invention, calculated as metal, is 100 μg / g to 2000 μg / g, preferably 300 μg / g to 1200 μg / g.

[0048] The first feedstock is preheated and then reacted with fresh catalytic cracking catalyst at a preheating temperature of 60°C to 90°C, preferably 70°C to 80°C. In one embodiment, the first feedstock is introduced into the reactor via an inlet pump under the boosting effect of high-purity nitrogen to react with the fresh catalytic cracking catalyst. The reaction temperature is 490°C to 530°C, preferably 500°C to 515°C, the catalyst-to-oil ratio is 5 to 30, preferably 10 to 20, the single-cycle inlet time is 1 min to 5 min, preferably 1.33 min to 1.5 min, and the mass flow rate of the first feedstock is 5 g / min to 15 g / min, preferably 6 g / min to 7.5 g / min.

[0049] After the first feedstock oil reacts with fresh catalytic cracking catalyst, hydrocarbon oil and gas are removed by stripping. In one embodiment, the stripping gas is nitrogen, with a flow rate of 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min, and a stripping time of 1 min to 10 min, preferably 2 min to 4 min. After nitrogen stripping, the temperature is raised to the coking temperature for coking regeneration. In one embodiment, regeneration is carried out in an oxidizing gas atmosphere, including, for example, one or more of the following: high-purity air, oxygen in nitrogen, sulfur dioxide in nitrogen, and other gases with oxidizing capabilities. The regeneration temperature is 680°C to 740°C, preferably 700°C to 720°C, and the regeneration time is 20 min to 40 min, preferably 30 min to 35 min. After regeneration, the gas is stripped again to cool down to the reaction temperature. The stripping gas is nitrogen, and the nitrogen flow rate is 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min. The nitrogen stripping time is 1 min to 10 min, preferably 2 min to 4 min.

[0050] After the stripping and cooling in step 1, one reaction process is completed. The above reaction, stripping, regeneration, and stripping processes are repeated at least once. Here, one cycle refers to one complete reaction, stripping, regeneration, and stripping process. In one embodiment, the number of cycles is 10 to 40, preferably 20 to 30. After multiple cycles, alkali metals, alkaline earth metals, and other transition metals (excluding iron) are loaded onto the catalyst surface.

[0051] Step 2 is as follows: the second feedstock oil is reacted with the catalytic cracking catalyst obtained in step 1, then stripped to remove hydrocarbon oil and gas, then regenerated by coking, and then stripped and cooled to complete one reaction process; then the fresh catalytic cracking catalyst is circulated with the first feedstock oil to react, strip, regenerate, and strip again, and the cycle is repeated at least once.

[0052] In the second step of heavy metal iron cyclic loading, this invention uses a small-volume, multiple-cycle loading mode. A small amount of organometallic iron is loaded in a single cycle, and through multiple cycles, the organometallic iron can be gradually deposited on the catalyst surface to generate iron nodules similar to those on industrial balance agents, thus simulating the distribution state of organometallic iron on industrial balance agents.

[0053] In this invention, an iron-containing compound is added to the second feedstock. The second feedstock can be one or more commonly used catalytic cracking feedstocks. For example, straight-run diesel, catalytic diesel, hydrotreated diesel, vacuum gas oil, atmospheric residue, coking gas oil, deasphalted oil, etc., preferably straight-run diesel, hydrotreated diesel, or mixtures thereof. Except for the added metal compound, the second feedstock can be the same as the first feedstock.

[0054] The iron-containing compound is an iron-containing organic compound, and more specifically, an oil-soluble iron-containing organic compound, such as at least one of ferric naphthenate, ferric stearate, and ferrocene.

[0055] The amount of iron-containing compounds added to the second feedstock is calculated based on the amount of fresh catalytic cracking catalyst added, the iron content of the target industrial equilibrium catalyst, the single-cycle feed time, the feed flow rate, and the total number of cycles. In one embodiment, the iron concentration in the second feedstock of the present invention, calculated as iron, is 100 μg / g to 2000 μg / g, preferably 500 μg / g to 1200 μg / g.

[0056] The second feedstock is preheated and then reacts with the catalytic cracking catalyst obtained in step 1. The preheating temperature of the second feedstock is 60℃~90℃, preferably 70℃~80℃. In one embodiment, the second feedstock is introduced into the reactor via an inlet pump under the boosting effect of high-purity nitrogen to react with the catalytic cracking catalyst obtained in step 1. The catalytic cracking reaction temperature is 490℃~530℃, preferably 500℃~515℃; the catalyst-to-oil ratio is 5~30, preferably 10~20; the single-cycle inlet time is 1min~5min, preferably 1.33min~1.5min; and the mass flow rate of the second feedstock is 5g / min~15g / min, preferably 6g / min~7.5g / min.

[0057] After the second feedstock oil reacts with the catalytic cracking catalyst obtained in step 1, hydrocarbon oil and gas are removed by stripping. In one embodiment, the stripping gas is nitrogen, with a flow rate of 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min, and a nitrogen stripping time of 1 min to 10 min, preferably 2 min to 4 min. After nitrogen stripping, the temperature is raised to the coking temperature for coking regeneration. In one embodiment, regeneration is carried out in an oxidizing gas atmosphere, including, for example, one or more of the following: high-purity air, oxygen in nitrogen, sulfur dioxide in nitrogen, and other gases with oxidizing capabilities. The regeneration temperature is 680℃ to 740℃, preferably 700℃ to 720℃, and the regeneration time is 20 min to 40 min, preferably 30 min to 35 min. After regeneration, the gas is stripped again to cool down to the reaction temperature. The stripping gas is nitrogen, and the nitrogen flow rate is 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min. The nitrogen stripping time is 1 min to 10 min, preferably 2 min to 4 min.

[0058] After cooling in step 2, one reaction cycle is complete. The above reaction, stripping, regeneration, and stripping processes are repeated at least once. Here, one cycle refers to one complete reaction, stripping, regeneration, and stripping process. In one embodiment, the number of cycles is 100 to 300, preferably 150 to 200. After multiple cycles, iron is loaded onto the catalyst surface.

[0059] Step 3 is to subject the catalytic cracking catalyst obtained in step 2 to hydrothermal aging treatment to obtain an industrial iron-contaminated catalytic cracking catalyst.

[0060] In one embodiment, the hydrothermal aging process of the present invention uses a gas with oxidizing and reducing properties, which causes the valence states of organometallic iron and other metals on the catalyst to be distributed in high and low valence states rather than a single high valence state, thus simulating the valence state distribution characteristics of organometallic compounds on industrial balancers.

[0061] In another embodiment, the hydrothermal aging process of the present invention first introduces a reducing gas to age the catalyst, then uses nitrogen stripping for a period of time, and then switches to an oxidizing gas for treatment. The order of reduction followed by oxidation can avoid the heavy metals on the catalyst undergoing hydrothermal aging in a high valence state at the beginning of each cycle, and reduce the destructive effect of the same amount of heavy metals nickel and vanadium on the catalyst.

[0062] In one embodiment, step 3, the hydrothermal aging process, includes:

[0063] The catalytic cracking catalyst obtained in step 2 is treated with a reducing gas, then with nitrogen, then with an oxidizing gas, and then with nitrogen again. This process of treating with a reducing gas, nitrogen, oxidizing gas, and nitrogen is repeated at least once to obtain an industrial iron-contaminated catalytic cracking catalyst.

[0064] In one embodiment, the catalytic cracking catalyst obtained in step 2 is treated with a certain amount of water vapor during the processes of treatment with a reducing gas, nitrogen, and oxidizing gas. The weight ratio of water vapor to reducing gas, water vapor to nitrogen, and water vapor to oxidizing gas is 30:70-55:45, preferably 40:60-50:50. The oxidizing gas is a gas with oxidizing ability, such as one or more of high-purity air, oxygen in nitrogen, and sulfur dioxide in nitrogen. The reducing gas is a gas with reducing ability, such as one or more of hydrogen in nitrogen, propylene in nitrogen, and carbon monoxide in nitrogen. The temperature for treatment with the reducing gas is 700℃~770℃, and the time is 2min~7min, preferably 3min~ The process involves treating a reducing gas at a flow rate of 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min for 5 min; treating a nitrogen gas at a temperature of 700℃ to 770℃ for 1 min to 10 min, preferably 2 min to 4 min, with a nitrogen flow rate of 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min; and treating an oxidizing gas at a temperature of 700℃ to 770℃ for 2 min to 7 min, preferably 3 min to 5 min, with an oxidizing gas flow rate of 500 ml / min to 1500 ml / min, preferably 880 ml / min to 1020 ml / min.

[0065] "Oxygen in nitrogen" means that nitrogen gas contains oxygen, and other similar expressions are used.

[0066] Here, "repeated once" refers to performing the treatment process once with a reducing gas, once with nitrogen, once with an oxidizing gas, and once with nitrogen. In one embodiment, step 3 is repeated 75 to 120 times, preferably 85 to 100 times.

[0067] In one embodiment, the method of the present invention is carried out in a catalytic cracking unit. Any catalytic cracking unit designed based on the fixed fluidized bed principle, such as one that has undergone partial modification of a fixed fluidized bed evaluation device to address catalyst recycling contamination, is a suitable testing device for this invention. In another embodiment, the method of the present invention is carried out in an MCD cyclic aging unit.

[0068] The method provided by this invention utilizes a circulating aging device. Except for the manual operation of preparing raw material oil and adding / unloading agents, all other operations are completed automatically and continuously. The operation is simple and can save a lot of time and manpower.

[0069] Furthermore, the iron contamination simulant obtained by pretreating fresh catalysts using this invention can simulate the state of industrial iron contamination balancers from multiple perspectives, including the simulation of iron nodule formation, the distribution location of iron, and the distribution of iron valence states. The results obtained through analysis and evaluation of this aging simulant are more instructive, pointing the way for scientific research and providing strong support for practical industrial applications.

[0070] The following examples will further illustrate the method provided by the present invention, but do not limit the invention. The LDR-600SR fresh catalytic cracking catalyst used in the examples and comparative examples was produced by the Catalyst Plant of Lanzhou Petrochemical Company, China National Petroleum Corporation. The LDR-600SR iron contamination industrial balancing agent was provided by Dalian West Pacific Petrochemical Co., Ltd.

[0071] Comparative Example 1

[0072] This comparative example uses the ACE-MODEL C evaluation device to evaluate the product distribution of LDR-600SR industrial equilibrium agent. 9g of the aforementioned LDR-600SR industrial equilibrium agent was used for the ACE evaluation agent-to-oil ratio experiment. The agent-to-oil ratio C / O was set to 5. The feedstock oil used was wax oil from the 3 million t / a catalytic cracking unit of Lanzhou Petrochemical Company, with a molecular weight of 354 g / mol and a viscosity of 5.52 mmHg at 100℃. 2 The density at 70℃ is 0.024 g / cm³. 3 The Concordant carbon residue was 0.07 m%. The evaluation conditions for the ACE-MODEL C evaluation apparatus were: reaction temperature 515℃, regeneration temperature 715℃, and cold trap temperature -13.5℃. The composition of the gaseous products was analyzed using INFICON online gas chromatography, and the composition of the liquid products was analyzed using Agilent 7890B simulated distillation chromatography.

[0073] The physicochemical properties of the LDR-600SR industrial equilibrium catalyst are shown in Table 2, and the ACE evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRA plus thermal field emission scanning electron microscope (FE-SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown below. Figure 1 .

[0074] Example 1

[0075] The feedstock used in this embodiment was wax oil from the 3 million t / a catalytic cracking unit of Lanzhou Petrochemical Company, which contained sodium isooctanoate, calcium stearate, vanadium naphthenate, and ferric naphthenate (the feedstock in step (I) contained sodium isooctanoate, calcium stearate, and vanadium naphthenate, and the feedstock in step (II) contained ferric naphthenate). The feed ratio was determined with the target values ​​for the amounts of heavy metals sodium, calcium, vanadium, and iron in the iron pollution industrial balancer in Comparative Agent 1. The experimental apparatus used was an MCD multi-channel circulating aging unit manufactured by the Dutch company 360KAS under a patent license from Albemarle. Cracking reaction, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out in the same quartz reactor.

[0076] The experimental steps are as follows:

[0077] (I) 150g of LDR-600SR fresh catalyst was added to the aforementioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst within the reactor. When the catalyst temperature reached 510℃, feedstock oil, preheated to 75℃ and doped with sodium isooctanoate, calcium stearate, and vanadium naphthenate organometallic compounds, was introduced into the reactor via a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of sodium in the feedstock oil was 350μg / g, the concentration of calcium was 170μg / g, and the concentration of vanadium was 500μg / g. The feedstock oil was injected from the bottom of the reactor, and the cracking reaction was stopped after 1.5 minutes of contact between the oil and the catalyst.

[0078] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 30 cycles are performed.

[0079] (II) Replace the feed oil with feedstock oil doped with ferric naphthenate. When the catalyst temperature stabilizes at 510°C, introduce the preheated feed oil (preheated to 75°C) into the reactor via a feed oil pump under the action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil is 750 μg / g. After 1.33 min of contact with the catalyst, the cracking reaction ends and the feed oil is stopped.

[0080] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 200 cycles are performed.

[0081] (III) The hydrothermal aging temperature was raised to 750℃. The water vapor weight ratio in the mixed gas was selected as 50%. After nitrogen stripping for 2 minutes, the treatment was switched to a reducing gas for 5 minutes, followed by another nitrogen stripping for 2 minutes, then switched to an oxidizing gas for 5 minutes. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were all set to 990 ml / min. The total number of cycles was 90, and the hydrothermal aging temperature remained constant throughout all cycles.

[0082] The physicochemical properties of the obtained iron-contaminated aging simulant were analyzed, and the results are shown in Table 2. 9g of the aging simulant was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRA plus thermal field emission scanning electron microscope (FE-SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 2. Figure 2 .

[0083] Example 2

[0084] The feedstock oil used in this embodiment was wax oil from the 3 million t / a catalytic cracking unit of Lanzhou Petrochemical Company, with added sodium isooctanoate, calcium stearate, vanadium naphthenate, and ferric naphthenate. The feed ratio was determined using the amounts of heavy metals sodium, calcium, vanadium, and iron in the iron contamination industrial balancer of Comparative Agent 1 as the target values. The experimental apparatus used was an MCD multi-channel circulating aging unit manufactured by the Dutch company 360KAS under a patent license from Albemarle. Cracking reaction, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out in the same quartz reactor.

[0085] The experimental steps are as follows:

[0086] (I) 150g of LDR-600SR fresh catalyst was added to the aforementioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst within the reactor. When the catalyst temperature reached 515℃, the organometallic feedstock oil, preheated to 80℃ and doped with sodium isooctanoate, calcium stearate, and vanadium naphthenate, was introduced into the reactor via a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of sodium in the feedstock oil was 350μg / g, the concentration of calcium was 170μg / g, and the concentration of vanadium was 500μg / g. The feedstock oil was injected from the bottom of the reactor, and the cracking reaction ended and oil feeding was stopped after 1.33 minutes of contact with the catalyst.

[0087] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 3 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 720℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 35 minutes. After regeneration, nitrogen stripping is performed for 3 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 25 cycles are performed.

[0088] (II) Replace the feed oil with feedstock oil doped with ferric naphthenate. When the catalyst temperature stabilizes at 515°C, introduce the preheated feed oil (preheated to 80°C) into the reactor via a feed oil pump under the action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil is 750 μg / g. After the oil-catalyst contact time is 1.5 min, the cracking reaction ends and the oil feeding is stopped.

[0089] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 4 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 720℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 35 minutes. After regeneration, nitrogen stripping is performed for 4 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 150 cycles are performed.

[0090] (III) The temperature was raised to 735℃ for hydrothermal aging. A steam ratio of 45% was selected. After nitrogen stripping for 3 minutes, the treatment was switched to a reducing gas for 4 minutes, followed by another 3 minutes of nitrogen stripping, then switched to an oxidizing gas for 4 minutes. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were set to 880 ml / min. The total number of cycles was 85, and the hydrothermal aging temperature remained constant throughout all cycles.

[0091] The physicochemical properties of the obtained iron-contaminated aging simulator were analyzed, and the results are shown in Table 2. 9g of the aging simulator was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1.

[0092] Example 3

[0093] The feedstock oil used in this embodiment was wax oil from the 3 million t / a catalytic cracking unit of Lanzhou Petrochemical Company, with added sodium isooctanoate, calcium stearate, vanadium naphthenate, and ferric naphthenate. The feed ratio was determined using the amounts of heavy metals sodium, calcium, vanadium, and iron in the iron contamination industrial balancer of Comparative Agent 1 as the target values. The experimental apparatus used was an MCD multi-channel circulating aging unit manufactured by 360KAS, a Dutch company licensed by Albemarle. Cracking, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out within the same quartz reactor.

[0094] The experimental steps are as follows:

[0095] (I) 150g of LDR-600SR fresh catalyst was added to the aforementioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst within the reactor. When the catalyst temperature reached 500℃, the organometallic feedstock oil, preheated to 70℃ and doped with sodium isooctanoate, calcium stearate, and vanadium naphthenate, was introduced into the reactor via a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of sodium in the feedstock oil was 350μg / g, the concentration of calcium was 170μg / g, and the concentration of vanadium was 500μg / g. The feedstock oil was injected from the bottom of the reactor, and the cracking reaction was stopped after 1.4 minutes of contact between the oil and the catalyst.

[0096] High-purity nitrogen gas was continuously introduced for stripping to remove hydrocarbon oil and gas for 4 minutes, during which time the system gradually heated up. Once the catalyst bed temperature reached 710℃, the system switched to an oxidizing gas to regenerate and remove coke, restoring activity for 33 minutes. After regeneration, nitrogen stripping was performed for 4 minutes, and the system automatically opened the reactor door to cool down in preparation for the next cycle. A total of 20 cycles were performed.

[0097] (II) Replace the feed oil with feedstock oil doped with ferric naphthenate. When the catalyst temperature stabilizes at 500℃, introduce the preheated feed oil (preheated to 70℃) into the reactor via a feed oil pump under the action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil is 750 μg / g. After the oil-catalyst contact time is 1.4 min, the cracking reaction ends and the oil feeding is stopped.

[0098] High-purity nitrogen gas was continuously introduced for stripping to remove hydrocarbon oil and gas for 3 minutes, during which time the system gradually heated up. Once the catalyst bed temperature reached 710℃, the system switched to an oxidizing gas to regenerate and remove coke, restoring activity for 33 minutes. After regeneration, nitrogen stripping was performed for 3 minutes, and the system automatically opened the reactor door to cool down in preparation for the next cycle. A total of 180 cycles were performed.

[0099] (III) The hydrothermal aging temperature was raised to 720℃. A steam ratio of 40% was selected. After nitrogen stripping for 4 minutes, the treatment was switched to a reducing gas for 3 minutes, followed by another 4 minutes of nitrogen stripping, then switched to an oxidizing gas for 3 minutes. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were set to 1020 ml / min. The total number of cycles was 100, and the hydrothermal aging temperature remained constant throughout all cycles.

[0100] The physicochemical properties of the obtained iron-contaminated aging simulator were analyzed, and the results are shown in Table 2. 9g of the aging simulator was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1.

[0101] Comparative Example 2

[0102] The fresh LDR-600SR catalyst was subjected to laboratory aging pretreatment using a conventional equal-volume impregnation method. The amount of heavy metal iron on the industrial equilibrium agent in contrast agent 1 was used as the target, and inorganic iron compounds were employed as the iron source.

[0103] The specific steps are as follows:

[0104] (I) Take 150g of fresh LDR-600SR catalyst and calcine it in a muffle furnace at 600℃ for 2h, then place it in a desiccator for later use.

[0105] (II) Calculate the amount of iron in the impregnation solution based on the amount of heavy metal iron on the industrial balance agent. Take 150g of deionized water, add 4.34g of ferric chloride, and stir until fully dissolved;

[0106] (III) First, pour the catalyst into a calcining dish, then pour in the impregnation solution and stir evenly. Add a small amount of deionized water to ensure that the catalyst surface is uniform and free of excess impregnation solution when the calcining dish is gently shaken. At this point, the total pore volume of the catalyst is equal to the volume of the impregnation solution. Then, dry the catalyst in a muffle furnace at 150°C for 2 hours, intermittently stirring the catalyst during the drying process to ensure no particle aggregation occurs. Finally, calcine the catalyst in a muffle furnace at 600°C for 2 hours to obtain the heavy metal-supported catalyst.

[0107] (IV) The heavy metal-supported catalyst was subjected to hydrothermal aging at 800℃ and 100% steam for 15 hours in a multi-sample catalyst rotary hydrothermal aging apparatus. The pre-aged catalyst was obtained. The physicochemical properties of this catalyst are shown in Table 2. The performance of this catalyst was evaluated using an ACE evaluation device. The raw materials and operating parameters used in the evaluation experiment were the same as those in Comparative Example 1. The final evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRAplus thermal field emission scanning electron microscope (SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 1. Figure 3 .

[0108] Comparative Example 3

[0109] The fresh LDR-600SR catalyst was subjected to laboratory aging pretreatment using a conventional equal-volume impregnation method. The amount of heavy metal iron on the industrial equilibrium agent in contrast agent 1 was used as the target, and an organoferric compound was employed as the iron source.

[0110] The specific steps are as follows:

[0111] (I) Take 150g of fresh LDR-600SR catalyst and calcine it in a muffle furnace at 600℃ for 2h, then place it in a desiccator for later use.

[0112] (II) Calculate the amount of iron in the impregnation solution based on the amount of heavy metal iron on the industrial balance agent. Take 100g of petroleum ether, add 25g of ferric naphthenate, and stir until fully dissolved;

[0113] (III) The catalyst was poured into a calcining dish, followed by the impregnation solution, and stirred evenly. A small amount of petroleum ether was added to ensure that the catalyst surface in the calcining dish was uniform and free of excess impregnation solution when gently shaken. At this point, the total pore volume of the catalyst was equal to the volume of the impregnation solution. The catalyst was then dried in a muffle furnace at 150°C for 2 hours, with intermittent stirring during the drying process to prevent the formation of aggregated particles. Finally, the catalyst was calcined in a muffle furnace at 600°C for 2 hours to obtain the heavy metal-supported catalyst.

[0114] (IV) The heavy metal-supported catalyst was subjected to hydrothermal aging at 800℃ and 100% steam for 15 hours in a multi-sample catalyst rotary hydrothermal aging apparatus. The pre-aged catalyst was obtained. The physicochemical properties of this catalyst are shown in Table 2. The performance of this catalyst was evaluated using an ACE evaluation device. The raw materials and operating parameters used in the evaluation experiment were the same as those in Comparative Example 1. The final evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRAplus thermal field emission scanning electron microscope (SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 1. Figure 4 .

[0115] Comparative Example 4

[0116] The LDR-600SR fresh agent was subjected to laboratory aging pretreatment using the traditional CD cycle aging contamination method.

[0117] The feedstock oil and aging apparatus used in this comparative example are the same as those in Example 1. The target metal content was determined by the iron content of the heavy metal on the industrial balance agent, and the calculated iron content in the feedstock oil was 1650 μg / g.

[0118] The experimental steps are as follows:

[0119] (I) Add 150g of LDR-600SR fresh catalyst to the above-mentioned MCD circulating aging unit. Use high-purity nitrogen to fluidize the catalyst in the reactor. When the catalyst temperature rises to 510℃, introduce the feed oil, which has been preheated to 75℃ and doped with ferric naphthenate, into the reactor through a feed oil pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The feed oil is injected from the bottom of the reactor. After the oil-catalyst contact time is 5 minutes, the cracking reaction ends and the oil feeding is stopped.

[0120] (II) Continue to introduce high-purity nitrogen for stripping to remove hydrocarbon oil and gas for 2 minutes, during which time the system gradually heats up. When the catalyst bed temperature reaches 700℃, the system switches to oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration and coke burning are completed, the system automatically switches to high-purity nitrogen stripping to remove oxidizing gases from the system for 3 minutes. At this time, the system opens the reactor door to cool down. Once the temperature drops to the cracking reaction temperature, the door automatically closes to begin the next cycle. In this step, all gases are accompanied by a certain proportion of water vapor, with a water vapor mass fraction of 50% in the mixed gas.

[0121] (III) The above cracking-stripping-regeneration-stripping is one cycle, and a total of 30 cycles are performed to obtain the final aging simulator.

[0122] The physicochemical properties of this catalyst are shown in Table 2. The performance of this catalyst was evaluated using an ACE evaluation device. The raw materials and operating parameters used in the evaluation experiment were the same as those in Comparative Example 1. The final evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using a Carl Zeiss ULTRA plus thermal field emission scanning electron microscope (FSE). The obtained electron microscope images are shown in Table 1. Figure 5 .

[0123] Comparative Example 5

[0124] The feedstock used in this comparative example was wax oil from the 3 million t / a catalytic cracking unit of Lanzhou Petrochemical Company, with added ferric naphthenate. The aging equipment used was the same as in Example 1. The feed ratio was adjusted to target the amount of heavy metal iron in the iron contamination industrial balancer in Comparative Agent 1. The cracking reaction, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out in the same quartz reactor.

[0125] The experimental steps are as follows:

[0126] (I) 150g of LDR-600SR fresh catalyst was added to the above-mentioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst in the reactor. When the catalyst temperature rose to 510℃, feed oil doped with ferric naphthenate, which had been preheated to 75℃, was introduced into the reactor through a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil was 750μg / g. The cracking reaction ended and the feed oil was stopped after 1.33min of contact between the oil and the catalyst.

[0127] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 200 cycles are performed.

[0128] (II) The hydrothermal aging temperature was raised to 750℃. A water vapor weight ratio of 50% was selected in the mixed gas. After nitrogen stripping for 2 minutes, the gas was switched to a reducing gas for 5 minutes, followed by another nitrogen stripping for 2 minutes, then switched to an oxidizing gas for 5 minutes. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were all set to 990 ml / min. The total number of cycles was 90, and the hydrothermal aging temperature remained constant throughout all cycles.

[0129] The physicochemical properties of the obtained iron-contaminated aging simulant were analyzed, and the results are shown in Table 2. 9g of the aging simulant was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRA plus thermal field emission scanning electron microscope (FE-SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 2. Figure 6 .

[0130] Comparative Example 6

[0131] The feedstock and aging equipment used in this comparative example were the same as those in Example 1. The feed ratio was adjusted to target the amounts of heavy metals sodium, calcium, vanadium, and iron in the iron contamination industrial balancer of Comparative Agent 1. Cracking, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out in the same quartz reactor.

[0132] The experimental steps are as follows:

[0133] (I) 150g of LDR-600SR fresh catalyst was added to the aforementioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst within the reactor. When the catalyst temperature reached 510℃, feedstock oil, preheated to 75℃ and doped with sodium isooctanoate, calcium stearate, and vanadium naphthenate organometallic compounds, was introduced into the reactor via a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of sodium in the feedstock oil was 350μg / g, the concentration of calcium was 170μg / g, and the concentration of vanadium was 500μg / g. The feedstock oil was injected from the bottom of the reactor, and the cracking reaction was stopped after 1.5 minutes of contact between the oil and the catalyst.

[0134] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 30 cycles are performed.

[0135] (II) Replace the feed oil with feedstock oil doped with ferric naphthenate. When the catalyst temperature stabilizes at 510°C, introduce the preheated feed oil (preheated to 75°C) into the reactor via a feed oil pump under the action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil is 1650 μg / g. After 1.33 min of contact with the catalyst, the cracking reaction ends and the feed oil is stopped.

[0136] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down.

[0137] (III) The hydrothermal aging temperature was raised to 750℃. The water vapor weight ratio in the mixed gas was selected as 50%. After nitrogen stripping for 2 minutes, the treatment was switched to a reducing gas for 5 minutes, followed by another nitrogen stripping for 2 minutes, then switched to an oxidizing gas for 5 minutes. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were all set to 990 ml / min. The total number of cycles was 90, and the hydrothermal aging temperature remained constant throughout all cycles.

[0138] The physicochemical properties of the obtained iron-contaminated aging simulant were analyzed, and the results are shown in Table 2. 9g of the aging simulant was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRA plus thermal field emission scanning electron microscope (FE-SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 2. Figure 7 .

[0139] Comparative Example 7

[0140] The feedstock and aging equipment used in this comparative example were the same as those in Example 1. The feed ratio was adjusted to target the amounts of heavy metals sodium, calcium, vanadium, and iron in the iron contamination industrial balancer of Comparative Agent 1. Cracking, high-temperature regeneration, hydrothermal aging, and redox post-treatment were all carried out in the same quartz reactor.

[0141] The experimental steps are as follows:

[0142] (I) 150g of LDR-600SR fresh catalyst was added to the aforementioned MCD circulating aging unit. High-purity nitrogen was used to fluidize the catalyst within the reactor. When the catalyst temperature reached 510℃, feedstock oil, preheated to 75℃ and doped with sodium isooctanoate, calcium stearate, and vanadium naphthenate organometallic compounds, was introduced into the reactor via a feed pump under the lifting action of fluidized high-purity nitrogen for cracking reaction. The concentration of sodium in the feedstock oil was 350μg / g, the concentration of calcium was 170μg / g, and the concentration of vanadium was 500μg / g. The feedstock oil was injected from the bottom of the reactor, and the cracking reaction was stopped after 1.5 minutes of contact between the oil and the catalyst.

[0143] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 30 cycles are performed.

[0144] (II) Replace the feed oil with feedstock oil doped with ferric naphthenate. When the catalyst temperature stabilizes at 510°C, introduce the preheated feed oil (preheated to 75°C) into the reactor via a feed oil pump under the action of fluidized high-purity nitrogen for cracking reaction. The concentration of heavy metal iron in the feed oil is 750 μg / g. After 1.33 min of contact with the catalyst, the cracking reaction ends and the feed oil is stopped.

[0145] High-purity nitrogen gas is continuously introduced for stripping to remove hydrocarbon oil and gas for 2 minutes, during which the system gradually heats up. Once the catalyst bed temperature reaches 700℃, the system switches to an oxidizing gas to regenerate and remove coke, restoring activity for 30 minutes. After regeneration, nitrogen stripping is performed for 2 minutes, and the system automatically opens the reactor door to cool down in preparation for the next cycle. A total of 200 cycles are performed.

[0146] (III) The hydrothermal aging temperature was raised to 750℃. The water vapor weight ratio in the mixed gas was selected as 50%. After nitrogen stripping for 2 minutes, the treatment was switched to an oxidizing gas for 5 minutes, followed by another 2 minutes of nitrogen stripping and then another 5 minutes of reducing gas treatment. After one more nitrogen stripping cycle, the next cycle began. The flow rates of nitrogen, oxidizing gas, and reducing gas were all set to 990 ml / min. The total number of cycles was 90, and the hydrothermal aging temperature remained constant throughout all cycles.

[0147] The physicochemical properties of the obtained iron-contaminated aging simulant were analyzed, and the results are shown in Table 2. 9g of the aging simulant was used for ACE evaluation experiments. The feedstock and operating parameters were the same as in Comparative Example 1. The evaluation results are shown in Table 1. The surface morphology of the catalyst was characterized using an ULTRA plus thermal field emission scanning electron microscope (FE-SEM) manufactured by Carl Zeiss AG, Germany. The obtained SEM images are shown in Table 2. Figure 8 .

[0148] As shown in Table 2, the heavy metal levels loaded on the aging simulators obtained in Examples 1, 2, 3, and Comparative Examples 6, 7 are basically the same as those on the industrial balance agent of Comparative Example 1. Comparative Examples 2, 3, 4, and 5, using conventional aging methods, only loaded heavy metal iron compounds, and the heavy metal iron levels on the resulting aging simulators were close to those on the industrial balance agent of Comparative Example 1. The specific surface area of ​​the aging simulators in Examples 1, 2, and 3 is close to that of Comparative Example 1. The specific surface area of ​​the aging simulators obtained in Comparative Examples 2, 3, 4, 5, 6, and 7 is significantly larger than that of Comparative Example 1. This is because Examples 1, 2, and 3, through two cycles of aging, multiple small-scale loading, and a hydrothermal method of reduction followed by oxidation, created an environment conducive to iron nodule formation on the catalyst surface, ultimately resulting in aging simulators with surfaces covered in iron nodules. The iron nodules block the pore structure of the catalyst, leading to a decrease in specific surface area and reduced microreactor activity. While Comparative Examples 2, 3, 4, 5, 6, and 7 all loaded the same amount of iron, the iron penetrated into the catalyst interior, and no significant iron nodules formed on the catalyst surface. Comparative Example 6, with only one iron loading, caused the organometallic compounds to precipitate from the solution before depositing on the catalyst under catalytic cracking conditions, failing to achieve the ideal metal deposition rate and thus not achieving effective loading. Multiple small loadings aim to increase the metal loading rate, ensuring all added iron is deposited on the catalyst. Comparative Example 7 used a hydrothermal condition of oxidation followed by reduction, causing the heavy metals on the catalyst to be in a high valence state at the beginning of each cycle, increasing the destructive effect of the same amount of nickel and vanadium on the catalyst. Therefore, these comparative examples cannot realistically simulate the contamination effect of heavy metal iron on industrial balancers.

[0149] As shown in Table 1, although the heavy metal iron loaded on Comparative Examples 2, 3, 4, 5, 6 and 7 was the same as that on Comparative Example 1, the aging agents obtained by these methods were basically free of iron nodules on their surfaces, and the pore structure of the catalyst was less affected. Therefore, under the same agent-to-oil ratio, the conversion rates of the five aging agents were higher than those of Comparative Example 1, and the gasoline and LPG yields were also higher, while the heavy oil and diesel yields were lower.

[0150] The aging simulators of Examples 1, 2, and 3 obtained using the method of this invention can match the iron contamination industrial balance agent well in terms of the distribution of multiple important products such as coke, hydrogen yield, and gasoline and diesel yield, achieving a realistic simulation effect for the industrial balance agent.

[0151] Depend on Figure 1 As shown, under the influence of iron contamination, the LDR-600SR industrial balancing agent exhibits a large number of nodular protrusions on its surface, known as iron nodules. Example 1 obtained by this invention ( Figure 2 As shown in the figure, a large number of iron nodules were also observed on the surface of the catalyst. Comparative Example 2 ( Figure 3 As shown, inorganic ferric chloride was used as the iron source, and the loaded iron was almost entirely absorbed into the catalyst interior, resulting in virtually no nodular protrusions on the catalyst surface. Comparative Example 3 ( Figure 4 As shown), Comparative Example 4 ( Figure 5 (as shown) and Comparative Example 5 ( Figure 6 As shown, using ferric organic naphthenate as the iron source, a small amount of iron nodules were formed on the catalyst surface, but it was not very obvious. Comparative Example 6 ( Figure 7 As shown, after one iron loading, the metal precipitated from the solution before it could be deposited on the catalyst, with virtually no nodular protrusions. Comparative Example 7 ( Figure 8 As shown, the hydrothermal method of oxidation followed by reduction increases the destructive effect of heavy metals nickel and vanadium on the catalyst. Therefore, the method of this invention can more realistically simulate the actual situation of industrial iron contamination.

[0152] Table 1

[0153]

[0154] Table 2

[0155]

[0156]

[0157] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the present invention.

Claims

1. A method for simulating the preparation of an industrial iron-contaminated catalytic cracking catalyst, characterized in that, Includes the following steps: Step 1: React the first feedstock oil with fresh catalytic cracking catalyst, then strip to remove hydrocarbon oil and gas, then regenerate by coking, then strip to cool, and then cycle the treated catalytic cracking catalyst with the first feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one. Step 2: React the second feedstock oil with the catalytic cracking catalyst obtained in Step 1, then strip to remove hydrocarbon oil and gas, then perform coke burning regeneration, then strip to cool down, and then cycle the treated catalytic cracking catalyst with the second feedstock oil to react, strip, regenerate, and strip again, with the cycle number being at least one. Step 3: The catalytic cracking catalyst obtained in Step 2 is subjected to hydrothermal aging treatment to obtain an industrial iron-contaminated catalytic cracking catalyst; the hydrothermal aging treatment includes: The catalytic cracking catalyst obtained in step 2 is treated with a reducing gas, then with nitrogen, then with an oxidizing gas, and then with nitrogen. This process of treating with a reducing gas, nitrogen, oxidizing gas, and nitrogen is repeated at least once. The first feedstock oil contains alkali metal compounds, alkaline earth metal compounds, and transition metal compounds other than iron, while the second feedstock oil contains iron-containing compounds. Wherein, the alkali metal compound is a sodium-containing organic compound, the alkaline earth metal compound is a calcium-containing organic compound, the transition metal compound other than iron is at least one of nickel-containing organic compounds, vanadium-containing organic compounds, and copper-containing organic compounds; and the iron-containing compound is an iron-containing organic compound.

2. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, The alkali metal compound is sodium isooctanoate and / or sodium naphthenate, the alkaline earth metal compound is calcium stearate, and the transition metal compound other than iron is nickel naphthenate, vanadium naphthenate, or copper naphthenate; the iron-containing compound is at least one of ferric naphthenate, ferric stearate, and ferrocene.

3. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, The metal concentration in the first feedstock oil is 100 μg / g to 2000 μg / g, calculated as metal; the metal concentration in the second feedstock oil is 100 μg / g to 2000 μg / g, calculated as metal.

4. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, The first feedstock is preheated and reacted with fresh catalytic cracking catalyst at a preheating temperature of 60℃~90℃, a reaction temperature of 490℃~530℃, a catalyst-to-oil ratio of 5~30, a single-cycle feed time of 1min~5min, and a mass flow rate of 5g / min~15g / min. The second feedstock is preheated and reacted with the catalytic cracking catalyst obtained in step 1 at a preheating temperature of 60℃~90℃, a reaction temperature of 490℃~530℃, a catalyst-to-oil ratio of 5~30, a single-cycle feed time of 1min~5min, and a mass flow rate of 5g / min~15g / min.

5. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, In step 1, the stripping removal of hydrocarbon oil and gas and the stripping cooling are both carried out under the action of nitrogen. The nitrogen flow rate is 500 mL / min to 1500 mL / min, and the nitrogen stripping time is 1 min to 10 min. The coke regeneration temperature is 680℃ to 740℃, and the coke regeneration time is 20 min to 40 min.

6. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, In step 2, the stripping removal of hydrocarbon oil and gas and the stripping cooling are both carried out under the action of nitrogen. The nitrogen flow rate is 500 mL / min to 1500 mL / min, and the nitrogen stripping time is 1 min to 10 min. The coke regeneration temperature is 680℃ to 740℃, and the coke regeneration time is 20 min to 40 min.

7. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, The catalytic cracking catalyst obtained in step 2 is treated with a certain amount of water vapor in the processes of reducing gas treatment, nitrogen treatment, and oxidizing gas treatment. The mass ratio of water vapor to reducing gas, water vapor to nitrogen, and water vapor to oxidizing gas is 30:70-55:

45. The oxidizing gas includes one or more of high-purity air, oxygen in nitrogen, and sulfur dioxide in nitrogen. The selected reducing gas includes one or more of hydrogen in nitrogen, propylene in nitrogen, and carbon monoxide in nitrogen. The temperature of the reducing gas treatment is 7°C. The temperature for the nitrogen treatment is 700℃~770℃, the time is 2min~7min, and the flow rate of the reducing gas is 500mL / min~1500mL / min; the temperature for the nitrogen treatment is 700℃~770℃, the time is 1min~10min, and the flow rate of the nitrogen gas is 500mL / min~1500mL / min; the temperature for the oxidizing gas treatment is 700℃~770℃, the time is 2min~7min, and the flow rate of the oxidizing gas is 500mL / min~1500mL / min.

8. The method for simulating the preparation of industrial iron-contaminated catalytic cracking catalyst according to claim 1, characterized in that, Step 1 is repeated 10 to 40 times, Step 2 is repeated 100 to 300 times, and Step 3 is repeated 75 to 120 times.

Images