A catalytic cracking slurry scale inhibitor and its preparation method

Abstract

This invention discloses a scale inhibitor for catalytic cracking slurry and its preparation method, belonging to the field of scale inhibitor technology. The scale inhibitor is composed of a main dispersant, a secondary dispersant, an antioxidant, tetrahydronaphthalene, a detergent, a metal passivator, a chelating agent, a long-chain functionalized ionic liquid, organic nanomaterials, and a solvent in a specific ratio. The main dispersant is a compound of T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A; the organic nanomaterials are ionized polyimide nanospheres; and the metal passivator is a multidentate phosphonic acid. The preparation method is as follows: heat the solvent to 50-65℃, add each component sequentially, and stir for 30-40 minutes. This invention achieves a full-chain protection of "dispersion-passivation-chelation-anti-adhesion" through multi-component synergy, achieving a scale inhibition rate of 97.0%-99.3%. It effectively inhibits asphaltene formation and metal catalytic dehydrogenation, exhibits excellent high-temperature stability, has a simple preparation process, and is suitable for the harsh conditions of catalytic cracking.

Description

Technical Field

[0001] This invention relates to the field of scale inhibitor technology, and in particular to a scale inhibitor for catalytic cracking slurry and its preparation method. Background Technology

[0002] Catalytic cracking (FCC) is a core process in the petroleum refining industry for converting heavy oil into lighter oil, playing a crucial role in crude oil deep processing and refined oil supply. FCC slurry, a byproduct of this process, is rich in aromatics, gums, asphaltenes, and metallic impurities such as Ni, V, and Fe. It easily forms stubborn scale layers in equipment such as heat exchangers and fractionation tower bottoms, posing a serious threat to the stable operation of the unit. The most economical, convenient, and effective way to solve this problem is to add a trace amount of slurry scale inhibitor to the processing medium to suppress scale formation.

[0003] Traditional oil slurry scale inhibitors generally suffer from poor high-temperature stability, insufficient dispersion, and inadequate scale inhibition effects. Existing oil slurry scale inhibitors also have various technical drawbacks, such as complex raw material composition, cumbersome preparation process, high cost, easy degradation under high-temperature conditions, weak inhibition of metal ion-catalyzed scaling, limited scale inhibition effect, poor component compatibility, insufficient stability, and large dosage.

[0004] To address the aforementioned issues, invention patent document CN117603734A discloses a slurry scale inhibitor for catalytic cracking units and its preparation method, relating to the field of slurry scale inhibition. The inhibitor comprises the following components by mass percentage: 15-25% dispersant; 1-5% antioxidant; and 72-82% solvent. This slurry scale inhibitor has a simple and easy preparation process, low cost, and can effectively improve the overall performance of the slurry scale inhibitor. However, the scale inhibition effect and high-temperature stability of this inhibitor still need further improvement.

[0005] Therefore, developing a scale inhibitor for catalytic cracking slurry that has significant scale inhibition effect, high temperature stability, strong synergistic effect, low dosage, and excellent compatibility with slurry oil has become a technical problem that urgently needs to be solved in the current petrochemical industry. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the prior art and provide a catalytic cracking slurry scale inhibitor with significant scale inhibition effect, high temperature stability, strong synergistic effect, low dosage and excellent compatibility with slurry, as well as its preparation method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a catalytic cracking slurry scale inhibitor, comprising the following components by weight: 20-22 parts of main dispersant, 10-12 parts of auxiliary dispersant, 2-3 parts of antioxidant, 1-2 parts of tetrahydronaphthalene, 12-15 parts of detergent, 3-5 parts of metal passivator, 3-5 parts of chelating agent, 3-5 parts of long-chain functionalized ionic liquid, 1-3 parts of organic nanomaterial, and 38-42 parts of solvent.

[0008] Preferably, the main dispersant is a mixture of T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A in a mass ratio of (2-4):1.

[0009] Preferably, the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155.

[0010] Preferably, the antioxidant is antioxidant T5570.

[0011] Preferably, the detergent is calcium dodecylbenzenesulfonate.

[0012] Preferably, the metal passivating agent is a multidentate phosphonic acid passivating agent.

[0013] Preferably, the multidentate phosphonic acid passivating agent is at least one of ethylenediaminetetramethylenephosphonic acid and aminotrimethylenephosphonic acid.

[0014] Preferably, the chelating agent is tetrasodium hydroxyethylidene diphosphonate.

[0015] Preferably, the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

[0016] Preferably, the organic nanomaterial is ionized polyimide nanospheres.

[0017] Preferably, there are no special requirements regarding the source of the ionized polyimide nanospheres. In one embodiment of the present invention, the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B.

[0018] Preferably, the solvent is a mixture of No. 200 solvent oil and S150 aromatic oil in a mass ratio of 1:(2-3).

[0019] Another objective of this invention is to provide a method for preparing the aforementioned catalytic cracking slurry scale inhibitor, comprising the following steps: first, heating the solvent to 50-65°C, then adding the remaining components in sequence according to the proportion, and stirring at 50-65°C for 30-40 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0020] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The catalytic cracking slurry scale inhibitor disclosed in this invention comprises the following components by weight: 20-22 parts of main dispersant, 10-12 parts of auxiliary dispersant, 2-3 parts of antioxidant, 1-2 parts of tetrahydronaphthalene, 12-15 parts of detergent, 3-5 parts of metal passivating agent, 3-5 parts of chelating agent, 3-5 parts of long-chain functionalized ionic liquid, 1-3 parts of organic nanomaterial, and 38-42 parts of solvent. Through the synergistic effect of the components, the prepared catalytic cracking slurry scale inhibitor exhibits significant scale inhibition effect, high-temperature stability, strong synergistic effect, low dosage, and excellent compatibility with slurry.

[0021] (2) The catalytic cracking slurry scale inhibitor disclosed in this invention uses T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A in a ratio of (2-4):1 to form a composite dispersion system with complementary functions. After the two are compounded, the "strong adsorption" of T2007A and the "strong steric hindrance" of T-161 work together to significantly improve the adsorption efficiency at high temperature and the dispersion stability time is long. At the same time, the optimized design of the compounding ratio (2-4):1 can be flexibly adjusted according to the concentration of scale precursor in the slurry: under low concentration conditions, the ratio of 4:1 is used to strengthen the steric hindrance, and under high concentration conditions, the ratio of 2:1 is used to increase the adsorption sites, which solves the problem of "narrow compatibility" of existing single dispersants. Polyisobutylene succinimide AT-155 is selected as a dedicated auxiliary dispersant. When used in conjunction with the main dispersant, it can form a multi-layered interlaced spatial steric network on the surface of scale particles, avoiding the "protective loopholes" caused by single chain length. This significantly improves the ability to control the particle size of asphaltene aggregates and reduces the formation of large-sized scale from the source.

[0022] (3) The scale inhibitor for catalytic cracking slurry disclosed in this invention introduces 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt (long-chain functionalized ionic liquid), which precisely matches the lipophilic requirements of FCC slurry with its long-chain C16 alkyl group, and has the triple core functions of "dispersion-passivation-interface regulation"—the imidazole cation can react with Ni 2 ⁺、V 5The ⁺ catalyst forms stable complexes with metal ions, and the auxiliary metal passivator reduces the catalytic activity of metal ions. The bis(trifluoromethanesulfonyl)imide anion can adsorb onto the surface of scale particles to reduce surface energy and inhibit aggregation. Moreover, the ionic bond structure gives it excellent high-temperature resistance. It effectively solves the pain points of poor oleophilicity, single function, and easy failure at high temperatures of short-chain ionic liquids in the existing technology. It works synergistically with the main and auxiliary dispersants, metal passivators and other components to significantly improve the adaptability of the scale inhibition system to inferior oil slurries with high metal impurity content and its long-term scale inhibition ability. The introduced ionized polyimide nanospheres, with the superior high-temperature resistance of the polyimide framework, combined with the ultra-large specific surface area brought by the nanoscale and the targeted adsorption capacity of the ionized groups, can form a "nano-isolation layer" on the surface of the scale precursor. This physically blocks the contact between particles and between particles and the equipment wall. In synergy with the chemical dispersion effect of the main and auxiliary dispersants, the amount of scale on the equipment wall is reduced. This effectively overcomes the shortcomings of existing inorganic nanomaterials, such as easy sintering at high temperatures, poor compatibility with oil slurry, and limited anti-adhesion effect. It significantly improves the long-term protection capability of the scale inhibition system and its adaptability to harsh working conditions.

[0023] (4) The scale inhibitor for catalytic cracking slurry disclosed in this invention constructs a triple synergistic system of "multidentate phosphonic acid passivator + tetrasodium hydroxyethylidene diphosphonate + calcium dodecylbenzenesulfonate", which targets and passivates Ni through multidentate phosphonic acid. 2 ⁺、V 5 To inhibit its dehydrogenation catalytic activity, tetrasodium hydroxyethylidene diphosphonate (THD) effectively chelates Fe by stabilizing the CP bond. 3 ⁺ To avoid dispersant failure, calcium dodecylbenzenesulfonate cleans the wall surface and forms a protective film to reduce adhesion sites. The three work together to reduce the scaling rate caused by metal ions, creatively achieving a full-chain protection of "catalysis inhibition - complexation stabilization - wall cleaning", which solves the pain point that the single functional component of the existing technology cannot fully inhibit the harm of metal ions.

[0024] (5) The scale inhibitor for catalytic cracking slurry disclosed in this invention uses antioxidant T5570. Its hindered phenolic structure and amine synergistic antioxidant groups can effectively inhibit the oxidative deterioration of the slurry, significantly reduce the viscosity growth rate of the slurry, and prolong the slurry stability period. It uses No. 200 solvent oil and S150 aromatic oil mixed at a ratio of 1:(2-3). S150 aromatic oil has excellent compatibility with FCC slurry and can fully dissolve each component (especially long-chain dispersants and ionic liquids). No. 200 solvent oil adjusts the viscosity of the system. Tetrahydronaphthalene, as a high aromatic solvent, can significantly improve the solubility of long-chain ionic liquids and polyimide nanospheres in the medium and low temperature range, and avoid the local precipitation of components to form new scale centers. The aromatic ring structure of tetrahydronaphthalene can compete with unsaturated hydrocarbons in the slurry for adsorption on the metal surface, inhibit the polymerization and coking of unsaturated hydrocarbons, and synergistically with antioxidant T5570 to further reduce the coking tendency of the slurry and reduce the amount of coking in the equipment. Detailed Implementation

[0025] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0026] Example 1 A scale inhibitor for catalytic cracking slurry comprises the following components in parts by weight: 20 parts of main dispersant, 10 parts of auxiliary dispersant, 2 parts of antioxidant, 1 part of tetrahydronaphthalene, 12 parts of detergent, 3 parts of metal passivator, 3 parts of chelating agent, 3 parts of long-chain functionalized ionic liquid, 1 part of organic nanomaterial, and 38 parts of solvent.

[0027] The main dispersant is a mixture of T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A in a mass ratio of 2:1; the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155; the antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate; the metal passivator is a multidentate phosphonic acid passivator; the multidentate phosphonic acid passivator is ethylenediaminetetramethylenephosphonic acid; the chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; the organic nanomaterial is ionized polyimide nanospheres; the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B; the solvent is a mixture of No. 200 solvent oil and S150 aromatic oil in a mass ratio of 1:2.

[0028] A method for preparing the aforementioned catalytic cracking slurry scale inhibitor includes the following steps: first, heating the solvent to 50°C, then adding the remaining components in sequence according to the proportion, and stirring at 50°C for 30 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0029] Example 2 A scale inhibitor for catalytic cracking slurry comprises the following components in parts by weight: 20.5 parts of main dispersant, 10.5 parts of auxiliary dispersant, 2.3 parts of antioxidant, 1.2 parts of tetrahydronaphthalene, 13 parts of detergent, 3.5 parts of metal passivator, 3.5 parts of chelating agent, 3.5 parts of long-chain functionalized ionic liquid, 1.5 parts of organic nanomaterial, and 39 parts of solvent.

[0030] The main dispersant is T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A mixed at a mass ratio of 2.5:1; the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155; the antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate; the metal passivator is a multidentate phosphonic acid passivator; the multidentate phosphonic acid passivator is aminotrimethylene phosphonic acid; the chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; the organic nanomaterial is ionized polyimide nanospheres; the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B; the solvent is No. 200 solvent oil and S150 aromatic oil mixed at a mass ratio of 1:2.2.

[0031] A method for preparing the aforementioned catalytic cracking slurry scale inhibitor includes the following steps: first, heating the solvent to 55°C, then adding the remaining components in sequence according to the proportion, and stirring at 55°C for 33 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0032] Example 3 A scale inhibitor for catalytic cracking slurry comprises the following components in parts by weight: 21 parts of main dispersant, 11 parts of auxiliary dispersant, 2.5 parts of antioxidant, 1.5 parts of tetrahydronaphthalene, 13.5 parts of detergent, 4 parts of metal passivator, 4 parts of chelating agent, 4 parts of long-chain functionalized ionic liquid, 2 parts of organic nanomaterial, and 40 parts of solvent.

[0033] The main dispersant is T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A mixed in a mass ratio of 3:1; the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155; the antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate; the metal passivator is a multidentate phosphonic acid passivator; the multidentate phosphonic acid passivator is ethylenediaminetetramethylenephosphonic acid; the chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; the organic nanomaterial is ionized polyimide nanospheres; the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B; the solvent is No. 200 solvent oil and S150 aromatic oil mixed in a mass ratio of 1:2.5.

[0034] A method for preparing the aforementioned catalytic cracking slurry scale inhibitor includes the following steps: first, heating the solvent to 58°C, then adding the remaining components in sequence according to the proportion, and stirring at 58°C for 35 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0035] Example 4 A scale inhibitor for catalytic cracking slurry comprises the following components in parts by weight: 21.5 parts of main dispersant, 11.5 parts of auxiliary dispersant, 2.8 parts of antioxidant, 1.8 parts of tetrahydronaphthalene, 14.5 parts of detergent, 4.5 parts of metal passivator, 4.5 parts of chelating agent, 4.5 parts of long-chain functionalized ionic liquid, 2.5 parts of organic nanomaterial, and 41 parts of solvent.

[0036] The primary dispersant is a mixture of T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A in a mass ratio of 3.5:1; the secondary dispersant is polyisobutylene succinimide dispersant AT-155; the antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate; the metal passivating agent is a multidentate phosphonic acid passivating agent; the multidentate phosphonic acid passivating agent is a mixture of ethylenediaminetetramethylenephosphonic acid and aminotrimethylenephosphonic acid in a mass ratio of 1:2. The chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; the organic nanomaterial is ionized polyimide nanospheres; the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B; the solvent is a mixture of No. 200 solvent oil and S150 aromatic oil in a mass ratio of 1:2.8.

[0037] A method for preparing the aforementioned catalytic cracking slurry scale inhibitor includes the following steps: first, heating the solvent to 63°C, then adding the remaining components in sequence according to the proportion, and stirring at 63°C for 38 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0038] Example 5 A scale inhibitor for catalytic cracking slurry comprises the following components in parts by weight: 22 parts of main dispersant, 12 parts of auxiliary dispersant, 3 parts of antioxidant, 2 parts of tetrahydronaphthalene, 15 parts of detergent, 5 parts of metal passivator, 5 parts of chelating agent, 5 parts of long-chain functionalized ionic liquid, 3 parts of organic nanomaterial, and 42 parts of solvent.

[0039] The main dispersant is a mixture of T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A in a mass ratio of 4:1; the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155; the antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate; the metal passivator is a multidentate phosphonic acid passivator; the multidentate phosphonic acid passivator is ethylenediaminetetramethylenephosphonic acid; the chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; the organic nanomaterial is ionized polyimide nanospheres; the ionized polyimide nanospheres are prepared according to the method of Example 1 of Chinese Invention Patent No. CN111875796B; the solvent is a mixture of No. 200 solvent oil and S150 aromatic oil in a mass ratio of 1:3.

[0040] A method for preparing the aforementioned catalytic cracking slurry scale inhibitor includes the following steps: first, heating the solvent to 65°C, then adding the remaining components in sequence according to the proportion, and stirring at 65°C for 40 minutes to obtain the catalytic cracking slurry scale inhibitor.

[0041] Comparative Example 1 This example provides a catalytic cracking slurry scale inhibitor and its preparation method, which is basically the same as in Example 1, except that no long-chain functionalized ionic liquid is added.

[0042] Comparative Example 2 This example provides a catalytic cracking slurry scale inhibitor and its preparation method, which is basically the same as in Example 1, except that no organic nanomaterials are added.

[0043] To further illustrate the beneficial technical effects of the catalytic cracking slurry scale inhibitors involved in the various embodiments of the present invention, relevant performance tests were conducted on the products of Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test methods are as follows: a stainless steel pipe was used as the slurry flow pipe, and an electric heating furnace was used for heating. The experimental temperature was 400℃. The experimental slurry was taken from the catalytic cracking workshop of a petrochemical company. The experimental time was 24 hours, and the amount of scale inhibitor added was 20 ppm. The scale inhibition rate was calculated by measuring the amount of scale buildup. At the same time, the asphaltene content in the slurry and the hydrogen content in the gas were measured: the lower the asphaltene content and the lower the hydrogen content, the better the scale inhibition effect of the scale inhibitor.

[0044] Table 1 Performance test results of scale inhibitors for catalytic cracking slurry oil As shown in Table 1, under the experimental conditions of 400℃, 24h, and an addition amount of 20ppm, the scale inhibitors of catalytic cracking slurry in Examples 1-5 of this technical solution showed a significant synergistic effect: with the optimization of the main dispersant compound ratio and the gradual increase in the dosage of components such as metal passivator / long-chain functionalized ionic liquid / ionized polyimide nanospheres, the scale inhibition rate steadily increased from 97.0% to 99.3%, the asphaltene content decreased from 2.2% to 1.0%, and the hydrogen content decreased from 0.25% to 0.10%. However, the lack of long-chain functionalized components resulted in a significant increase in scale inhibition rate from 97.0% to 99.3%, while the asphaltene content decreased from 2.2% to 1.0%, and the hydrogen content decreased from 0.25% to 0.10%. Comparative Example 1, with functionalized ionic liquid, and Comparative Example 2, with ionized polyimide nanospheres lacking ionization, showed scale inhibition rates of only 92.3% and 93.1%, respectively. The asphaltenes content (3.5% and 3.2%) and hydrogen content (0.45% and 0.40%) were significantly higher than those of the examples, fully verifying the key role of these two core components in the "dispersion-passivation-anti-adhesion" synergistic system. This highlights the significant advantages of this technical solution compared to the system lacking key components in terms of scale inhibition efficiency, inhibition of asphaltenes formation, and metal-catalyzed dehydrogenation reaction.

[0045] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A catalytic cracking slurry oil scale inhibitor characterized by, The product comprises the following components by weight: 20-22 parts of main dispersant, 10-12 parts of auxiliary dispersant, 2-3 parts of antioxidant, 1-2 parts of tetrahydronaphthalene, 12-15 parts of detergent, 3-5 parts of metal passivator, 3-5 parts of chelating agent, 3-5 parts of long-chain functionalized ionic liquid, 1-3 parts of organic nanomaterials, and 38-42 parts of solvent; the main dispersant is T-161 ashless dispersant and polyisobutylene maleic anhydride T2007A mixed in a mass ratio of (2-4):1; the auxiliary dispersant is polyisobutylene succinimide dispersant AT-155; the metal passivator is a multidentate phosphonic acid passivator; the chelating agent is tetrasodium hydroxyethylidene diphosphonate; the long-chain functionalized ionic liquid is 1-hexadecyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt; and the organic nanomaterials are ionized polyimide nanospheres.

2. The catalytic cracking slurry oil scale inhibitor of claim 1, wherein, The antioxidant is antioxidant T5570; the detergent is calcium dodecylbenzenesulfonate.

3. The catalytic cracking slurry oil scale inhibitor of claim 1, wherein, The multidentate phosphonic acid passivating agent is at least one of ethylenediaminetetramethylenephosphonic acid and aminotrimethylenephosphonic acid.

4. The scale inhibitor for catalytic cracking slurry oil according to claim 1, characterized in that, The solvent is a mixture of No. 200 solvent oil and S150 aromatic oil in a mass ratio of 1:(2-3).

5. A method for preparing a scale inhibitor for catalytic cracking slurry oil according to any one of claims 1-4, characterized in that, The process includes the following steps: First, heat the solvent to 50-65°C, then add the remaining components in proportion, and stir at 50-65°C for 30-40 minutes to obtain the catalytic cracking slurry scale inhibitor.

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