A scale inhibiting composition and its use

Abstract

The present disclosure relates to a scale inhibiting composition and application thereof, the scale inhibiting composition comprising a diluent and a detergent dispersant, the diluent comprising a hydrocarbon substance with a boiling point of 180-410 DEG C, and the detergent dispersant having a structure shown in formula (1). The scale inhibiting composition of the present disclosure has high descaling efficiency and good high temperature resistance, and is suitable for processing of high-acid, high-sulfur and poor-quality crude oil.

Description

Technical Field

[0001] This disclosure relates to the field of petroleum processing, and more specifically, to a scale inhibitor composition and its application. Background Technology

[0002] As crude oil quality continues to deteriorate, hydrocracking units that primarily use vacuum gas oil as feedstock also gradually deteriorate, leading to new problems for their normal operation. One such problem is scaling in the high-pressure heat exchanger, causing a decrease in heat exchange efficiency. This results in the feedstock temperature failing to meet design requirements, necessitating increased furnace load, which increases energy consumption and, in severe cases, causes significant deviations in reactor bed temperature distribution, impacting the unit's long-term safe operation. There are two main approaches to address this issue: one is a process-based approach, which can be achieved by adding auxiliary equipment (such as backup heat exchangers or filters), improving process flow and operation (such as altering feedstock flow rates), and controlling feedstock properties; the other is to add a certain amount of high-efficiency scale inhibitor to the feedstock oil to inhibit and delay the formation of coke scale in the feedstock heat exchanger. Adding scale inhibitors does not alter the process flow, does not affect normal operation, is convenient and flexible, requires minimal investment, and has a short payback period.

[0003] Analysis of published patents reveals that research on low-molecular-weight surfactant-type scale inhibitors is relatively abundant, primarily focusing on ammonium salts of phosphoric acid or thiophosphate esters. High-molecular-weight dispersants, represented by polyisobutylene maleic acid derivatives, have emerged later and are less studied. With the depletion of global oil resources, the availability of high-quality crude oil for extraction is decreasing, while the processing volume of low-quality crude oil with high asphaltene and gum content is gradually increasing. Therefore, high-molecular-weight scale inhibitors that can stably disperse gums and prevent their deposition on equipment surfaces will find increasingly widespread application in petroleum processing.

[0004] There are no reports on scale inhibitor compositions suitable for processing high-acid, high-sulfur, and heavy crude oil. When the sulfur content in crude oil is high, sulfur compounds and acidic components exacerbate equipment corrosion, leading to the formation of large amounts of inorganic coke. Metal ions in inorganic coke can further promote the oxidation of oil at high temperatures, forming organic coke, while the adhesion of organic coke, in turn, intensifies the formation of inorganic coke. In addition, sulfur- and nitrogen-containing compounds in oil are prone to free radical oxidation under the action of oxygen, generating gum and carbon deposits. This makes the coke formation mechanism in petroleum processing equipment complex, with poor high-temperature resistance, and the decomposition products have a negative impact on the processing process and catalysts. Summary of the Invention

[0005] The purpose of this disclosure is to provide a scale inhibitor composition and its application, which has high descaling efficiency, good high temperature resistance, and is suitable for processing high-acid, high-sulfur, and low-quality crude oil.

[0006] To achieve the above objectives, a first aspect of this disclosure provides a scale inhibitor composition comprising a diluent and a detergent-dispersant, wherein the diluent comprises a hydrocarbon having a boiling point of 180-410°C, and the detergent-dispersant has the structure shown in formula (1):

[0007]

[0008] Among them, R1, R2, R3 and R4 may be the same as or different from each other, and are independently selected from H, halogen groups, cyano groups and alkyl groups having 1-10 carbon atoms;

[0009] n1 represents the number of R1s, n2 represents the number of R2s, n3 represents the number of R3s, and n4 represents the number of R4s; n1, n2, n3, and n4 may be the same as or different from each other, and are independently selected from 1, 2, 3, or 4 respectively;

[0010] L is selected from a single bond or an alkylene group having 1-5 carbon atoms; PIB represents polyisobutylene.

[0011] Optionally, R1, R2, R3 and R4 are the same and selected from H, halogen groups, cyano groups and alkyl groups having 1-10 carbon atoms; n1, n2 and n3 are the same and selected from 1, 2, 3 or 4.

[0012] Optionally, R1, R2, R3, and R4 are each H, and L is a single bond.

[0013] Optionally, the detergent dispersant has the structure shown in formula (1-1):

[0014]

[0015] Optionally, the diluent includes one or more of diesel oil, aviation kerosene, and heavy aromatics.

[0016] Optionally, the content of the detergent-dispersant is 1-30% by weight, preferably 5-25% by weight, relative to the total weight of the scale inhibitory composition.

[0017] Optionally, the scale inhibitor composition further comprises an antioxidant, which includes one or more of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants and thiophenolic antioxidants;

[0018] The antioxidant content is 0.05-2% by weight relative to the total weight of the scale inhibitor composition.

[0019] Optionally, the scale inhibitor composition further comprises a rust inhibitor, which includes one or more of petroleum sulfonates, imidazole compounds, imidazole-alkenyl succinate, alkenyl succinic acid, thiadiazole compounds, and alkenyl succinates.

[0020] The content of the rust inhibitor is 0.1-5% by weight relative to the total weight of the scale inhibitor composition.

[0021] A second aspect of this disclosure provides a method for preparing the scale inhibitor composition described in the first aspect of this disclosure, the method comprising the following steps:

[0022] S1 brings the first reactant and the second reactant into contact and react in the first solvent to obtain an intermediate product;

[0023] S2 reacts the intermediate product and polyisobutylene maleic anhydride in a second solvent to obtain the detergent-dispersant.

[0024] S3 mixes the cleaning dispersant, the diluent, and optional additives;

[0025] The first reactant has the structure shown in formula (2), and the second reactant has the structure shown in formula (3) or formula (4):

[0026]

[0027] R5 is selected from alkyl groups having 1-10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 carbon atoms, and substituted or unsubstituted aryl groups having 6-15 carbon atoms.

[0028] The substituents in the substituted aryl and substituted cycloalkyl groups are each independently selected from one or more of deuterium, halogen groups, and alkyl groups having 1-5 carbon atoms.

[0029] Optionally, the second reactant is selected from one of indomethacin anhydride, 6-methylindomethacin, and 6,8-dibromoindomethacin anhydride; or,

[0030] The second reactant is selected from one of pentane p-aminobenzoate, ethyl 2-aminobenzoate, menthol an-aminobenzoate, and benzyl p-aminobenzoate;

[0031] Preferably, the second reactant is indomethacin anhydride.

[0032] Optionally, in step S1, the molar ratio of the first reactant to the second reactant is 1:(3-3.5), preferably 1:(3-3.2);

[0033] The reaction conditions include: a reaction temperature of 80-100℃, preferably 85-95℃; a reaction time of 8-12h, preferably 9-10h; and the first solvent including one or more of toluene, benzene, and xylene, preferably toluene.

[0034] Optionally, in step S2, the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.5), preferably 1:(3-3.2);

[0035] The reaction conditions include: a reaction temperature of 140-160℃, preferably 145-155℃; and a reaction time of 4-8h, preferably 5-7h.

[0036] The polyisobutylene maleic anhydride has a number average molecular weight of 800-2500, preferably 1000-2300; the second solvent is a base oil, preferably 150SN or white oil, more preferably 150SN.

[0037] Optionally, in step S3, the mixing conditions include: a temperature of 20-60°C and a time of 0.5-4 hours;

[0038] Optionally, the additive includes the antioxidant and / or the rust inhibitor.

[0039] This disclosure provides a third aspect regarding the use of the scale inhibitor composition described in the first aspect of this disclosure in scale inhibition in crude oil processing equipment.

[0040] Optionally, the method for scale inhibition in the crude oil processing unit includes: mixing the scale inhibition composition with crude oil and then introducing it into the crude oil processing unit; the amount of the scale inhibition composition used is 100-1000 mg relative to 1 kg of crude oil;

[0041] The crude oil has a sulfur content of 1.5-2.5% by weight and an acid value of 0.15-0.25 mg KOH / g;

[0042] The crude oil processing unit includes pipelines and / or heat exchangers.

[0043] Through the above technical solution, the detergent-dispersant disclosed herein comprises a polyamide compound with a centrosymmetric structure. Its structure is centered on an N atom and contains multiple symmetrically positioned amide functional groups and multiple benzene rings. This compound exhibits high overall structural symmetry. Scale inhibitor compositions comprising this detergent-dispersant demonstrate high scale inhibition efficiency and good high-temperature resistance, making them suitable for processing high-acid, high-sulfur, and low-quality crude oils. The preparation method of this disclosure is simple and has high synthesis efficiency.

[0044] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 This is the infrared spectrum of the cleaning and dispersing agent F1 prepared in Example 1 of this disclosure;

[0047] Figure 2 This is the infrared spectrum of intermediate product A1 prepared in Example 1 of this disclosure. Detailed Implementation

[0048] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0049] The first aspect of this disclosure provides a scale inhibitor composition comprising a diluent and a detergent-dispersant, the diluent comprising a hydrocarbon having a boiling point of 180-410°C, and the detergent-dispersant having the structure shown in formula (1):

[0050]

[0051] Among them, R1, R2, R3 and R4 may be the same as or different from each other, and are independently selected from H, halogen groups, cyano groups and alkyl groups having 1-10 carbon atoms;

[0052] n1 represents the number of R1s, n2 represents the number of R2s, n3 represents the number of R3s, and n4 represents the number of R4s; n1, n2, n3, and n4 may be the same as or different from each other, and are independently selected from 1, 2, 3, or 4 respectively;

[0053] L is selected from a single bond or an alkylene group having 1-5 carbon atoms; PIB represents polyisobutylene.

[0054] The cleaning and dispersing agent disclosed herein is a compound with a polyamide structure as shown in formula (1). This polyamide compound has multiple electron-donating amide groups and contains numerous large conjugated systems, exhibiting good structural symmetry. Scale inhibitor compositions containing this compound exhibit high descaling efficiency and good high-temperature resistance, making them suitable for processing high-acid, high-sulfur, and low-quality crude oils.

[0055] In this disclosure, when n1 is greater than 1, R1 is the same or different; when n2 is greater than 1, R2 is the same or different; when n3 is greater than 1, R3 is the same or different; when n4 is greater than 1, R4 is the same or different.

[0056] In this disclosure, a single bond refers to a portion represented by L where no other atoms exist. For example, when L in equation (1) is a single bond, N can be directly attached to the benzene ring.

[0057] In one embodiment of this disclosure, R1, R2, R3, and R4 are identical and selected from H, halogens, cyano groups, and alkyl groups having 1-10 carbon atoms; n1, n2, and n3 are identical and selected from 1, 2, 3, or 4. Specifically, R1, R2, R3, and R4 can simultaneously be H, halogens, cyano groups, methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, tert-butyl groups, n-pentyl groups, isopentyl groups, neopentyl groups, hexyl groups, heptyl groups, octyl groups, 2-ethylhexyl groups, nonyl groups, decyl groups, etc., but are not limited thereto. More preferably, the substitution positions of R1, R2, R3 and R4 on their respective benzene rings can be the same, that is, the connection positions of R1, R2, R3 and R4 on their respective benzene rings have the same relative positional relationship with the amide group. For example, R1, R2, R3 and R4 are respectively ortho to the amide group on their respective benzene rings, or R1, R2, R3 and R4 are respectively meta to the amide group on their respective benzene rings.

[0058] In one embodiment of this disclosure, R1, R2, R3 and R4 are each H, and L is a single bond.

[0059] In one embodiment of this disclosure, the polyamide compound has the structure shown in formula (1-1):

[0060]

[0061] In one embodiment of this disclosure, the diluent comprises one or more of diesel oil, aviation kerosene, and heavy aromatics, preferably including one or more of No. 5 diesel oil, No. 0 diesel oil, No. -10 diesel oil, No. -20 diesel oil, No. -35 diesel oil, No. 1 aviation kerosene, No. 2 aviation kerosene, No. 3 aviation kerosene, No. 4 aviation kerosene, C9 aromatics, DAH-type heavy aromatics, DAM-type heavy aromatics, and DAL-type heavy aromatics, and more preferably includes No. 0 diesel oil and / or C9 aromatics.

[0062] In one embodiment of this disclosure, the content of the detergent-dispersant is 1-30% by weight, preferably 5-25% by weight, and more preferably 13-20% by weight, relative to the total weight of the scale inhibitory composition.

[0063] In one embodiment of this disclosure, the scale inhibitor composition further comprises an antioxidant, said antioxidant including one or more of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants, and thiophenolic antioxidants, such as 2,6-di-tert-butyl-p-cresol, 4,4-methylenebis(2,6-di-tert-butylphenol), 2,6-di-tert-butyl-4-alkoxyphenol, 2,6-di-tert-butyl-α-dimethylamino-p-cresol, N-phenyl-α-naphthylamine, etc. Octyl diphenylamine, dinonyl diphenylamine, p,p'-diisooctyl diphenylamine, tert-butyl / isooctyl diphenylamine, 4,4'-thiobis(3-methyl-6-tert-butylphenol) and 2,2'-thiobis(4,6-di-tert-butyl-resorcinol); the antioxidant preferably includes one or more alkylated diphenylamine antioxidants, and further includes one or more diphenylamine antioxidants having alkyl substituents having 4-8 carbon atoms.

[0064] According to one embodiment of this disclosure, the antioxidant content is 0.05-2% by weight, preferably 0.05-1.2% by weight, and more preferably 0.08-1.2% by weight, relative to the total weight of the scale inhibitor composition.

[0065] In one embodiment of this disclosure, the scale inhibitor composition further comprises a rust inhibitor, which includes one or more of petroleum sulfonates, imidazole compounds, imidazole-linyl succinate, alkenyl succinic acid, thiadiazole compounds, and alkenyl succinates. For example, it may include one or more of barium petroleum sulfonate, sodium petroleum sulfonate, 4,5-dihydroimidazole, heptadecyl imidazole-linyl succinate, dodecyl succinic acid, 2,5-dimercapto-1,3,4-thiadiazole, and dodecyl succinate. The rust inhibitor preferably includes imidazole-linyl succinate, alkenyl succinate, and 2,5-dimercapto-1,3,4-thiadiazole, and more preferably imidazole-linyl succinate and / or 2,5-dimercapto-1,3,4-thiadiazole.

[0066] In one embodiment of this disclosure, the content of the rust inhibitor is 0.1-5% by weight, preferably 1-3% by weight, and more preferably 1-2% by weight, relative to the total weight of the scale inhibitor composition.

[0067] In this disclosure, "comprising one or more of..." and "selected from one or more of..." have the same meaning, referring to any one, any two, any three, etc., within the scope. For example, "the diluent comprises one or more of diesel, aviation kerosene, and heavy aromatics" means that the diluent comprises any one, any two, or any three of diesel, aviation kerosene, and heavy aromatics; as another example, "the antioxidant comprises one or more of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants, and thiophenolic antioxidants" means that the antioxidant comprises any one, any two, any three, or any four of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants, and thiophenolic antioxidants.

[0068] A second aspect of this disclosure provides a method for preparing the scale inhibitor composition described in the first aspect of this disclosure, the method comprising the following steps:

[0069] S1 brings the first reactant and the second reactant into contact and react in the first solvent to obtain an intermediate product;

[0070] S2 reacts the intermediate product and polyisobutylene maleic anhydride in a second solvent to obtain the detergent-dispersant.

[0071] S3 mixes the cleaning dispersant, the diluent, and optional additives;

[0072] The first reactant has the structure shown in formula (2), and the second reactant has the structure shown in formula (3) or formula (4):

[0073]

[0074] R5 is selected from alkyl groups having 1-10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 carbon atoms, and substituted or unsubstituted aryl groups having 6-15 carbon atoms.

[0075] The substituents in the substituted aryl and substituted cycloalkyl groups are each independently selected from one or more of deuterium, halogen groups, and alkyl groups having 1-5 carbon atoms.

[0076] In one embodiment of this disclosure, R5 is selected from alkyl groups having 1-5 carbon atoms, substituted or unsubstituted cycloalkyl groups having 6-10 carbon atoms, and substituted or unsubstituted aryl groups having 6-10 carbon atoms.

[0077] In one embodiment of this disclosure, the second reactant is selected from one of indocyanine anhydride, 6-methylindocyanine, and 6,8-dibromoindocyanine anhydride; or, the second reactant is selected from one of pentane p-aminobenzoate, ethyl 2-aminobenzoate, menthol o-aminobenzoate, and benzyl p-aminobenzoate; in a preferred embodiment, the second reactant is indocyanine anhydride.

[0078] In one embodiment of this disclosure, in step S1, the molar ratio of the first reactant to the second reactant is 1:(3-3.5), preferably 1:(3-3.2); the reaction conditions include: a reaction temperature of 80-100℃, preferably 85-95℃; and a reaction time of 8-12h, preferably 9-10h.

[0079] In one embodiment of this disclosure, in step S2, the molar ratio of the intermediate product to polyisobutylene maleic anhydride is 1:(3-3.5); preferably 1:(3-3.2); the reaction conditions include: a reaction temperature of 140-160℃, preferably 145-155℃; and a reaction time of 4-8h, preferably 5-7h.

[0080] In one embodiment of this disclosure, the number average molecular weight of polyisobutylene maleic anhydride is 800-2500, preferably 1000-2300.

[0081] In one embodiment of this disclosure, in step S1, the first solvent includes one or more of toluene, benzene, and xylene, preferably toluene.

[0082] In one embodiment of this disclosure, in step S2, the second solvent is a base oil, preferably 150SN or white oil, more preferably 150SN.

[0083] In a preferred embodiment, the reactions in steps S1 and S2 are carried out under the protection of an inert gas, which is nitrogen, helium or argon, preferably nitrogen.

[0084] In one embodiment of this disclosure, in step S1, the amount of the first solvent used is 100-200 mL relative to 0.01 mol of the first reactant; in step S2, the amount of the second solvent used is 0.5-1 mL relative to 1 mL of the first solvent.

[0085] In one embodiment of this disclosure, in step S3, the mixing conditions include: a temperature of 20-60°C and a time of 0.5-4 hours; optionally, the additives include antioxidants and / or rust inhibitors, and the amount of antioxidants and rust inhibitors used is sufficient to meet the content range of antioxidants and rust inhibitors in the scale inhibitor composition.

[0086] In one embodiment of this disclosure, the method further includes: after steps S1 and S2 are completed, removing the first solvent and the second solvent respectively; the method for removing the solvent is conventional in the art, such as rotary evaporation.

[0087] This disclosure provides a third aspect regarding the use of the scale inhibitor composition described in the first aspect of this disclosure in scale inhibition in crude oil processing equipment.

[0088] In one embodiment of this disclosure, the method for scale inhibition in a crude oil processing unit includes: mixing a scale inhibition composition with crude oil and then introducing it into the crude oil processing unit; the amount of the scale inhibition composition used relative to 1 kg of crude oil is 100-1000 mg, preferably 150-1000 mg, and more preferably 200-1000 mg.

[0089] In this disclosure, the scale inhibitor composition is used at a temperature of 100-300°C, that is, within the above temperature range, the scale inhibitor composition of this disclosure has high scale inhibition efficiency.

[0090] In one embodiment of this disclosure, the crude oil has a sulfur content of 1.5-2.5% by weight and an acid value of 0.15-0.25 mg KOH / g.

[0091] In one embodiment of this disclosure, the crude oil processing apparatus includes a delivery pipeline and / or a heat exchanger; specifically, the scale inhibitor composition and crude oil can be directly fed into the heat exchanger in a specific ratio.

[0092] Other features and advantages of this disclosure will be described in detail in the following detailed description section.

[0093] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0094] The intermediate products and the prepared detergent-dispersant disclosed herein were tested using an infrared spectrometer. The testing method was as follows: Fourier transform infrared spectrometer (FTIR) was an AVATAR 360 model from NICOLET, USA. Solid samples were prepared by mixing and grinding with dry KBr, then pressing into tablets for testing. Transmission mode was selected, and the scanning range was 4000-4000 cm⁻¹. -1 .

[0095] The parameters and sources of some of the reagents used in the examples and comparative examples are as follows:

[0096] Polyisobutylene maleic anhydride: Mw (number average molecular weight) = 1000, purchased from Xinxiang Ruifeng New Materials Co., Ltd.

[0097] Indocyanine anhydride: purchased from Ark Pharm;

[0098] Tris(4-aminophenyl)amine: purchased from Ark Pharm;

[0099] Dioctyldiphenylamine: Purchased from Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.;

[0100] 2,5-Dimercapto-1,3,4-Thiadiazole: purchased from Jinzhou Kangtai Lubricating Oil Additives Co., Ltd.;

[0101] 3,5-Di-tert-butyl-4-hydroxyphenyl methyl acrylate: purchased from Hubei Chushengwei Chemical Co., Ltd.;

[0102] Dodecenyl succinic acid: Hubei Chushengwei Chemical Co., Ltd.;

[0103] Toluene: purchased from Xilong Scientific;

[0104] 150SN: Shanghai Gaoqiao Petrochemical;

[0105] No. 0 diesel: purchased from Yanshan Petrochemical.

[0106] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available products.

[0107] Example 1

[0108] Detergent dispersant F1 was prepared using the following steps:

[0109] (1) Add 4.89 g (0.03 mol) indomethacin anhydride and 2.9 g (0.01 mol) tris(4-aminophenyl)amine to a 500 mL reactor, add 160 mL of toluene, purge with nitrogen, turn on the cooling water for reflux, and react at 90 °C for 10 hours. After the reaction is completed, rotary evaporate to remove toluene and obtain intermediate product A1.

[0110] (2) Add 33g of polyisobutylene maleic anhydride dissolved in 100mL of 150SN to intermediate product A1, purge with nitrogen, turn on the cooling water, and react at 150℃ for 6h. After the reaction is complete, remove the solvent by rotary evaporation to obtain a cleaning dispersant F1. The reaction formula is as follows:

[0111]

[0112] Infrared spectroscopy was performed on the obtained detergent dispersant F1 and intermediate product A1, respectively. Figure 1 This is the infrared spectrum of detergent dispersant F1. Figure 2 This is the infrared spectrum of intermediate product A1.

[0113] Depend on Figure 1 and Figure 2 It can be seen that the absorption peak of the primary amine attached to the benzene ring in the intermediate product is at 3349 cm⁻¹. -1Near the same location, the absorption peak disappears after reacting with polyisobutylene maleimide; the absorption peak of the amide in the intermediate product is at 1600 cm⁻¹. -1 Near the same point, the absorption peak weakens after reacting with polyisobutylene maleimide; the absorption peak of the newly formed imide in the product is at 1700 cm⁻¹. -1 nearby. Figure 1 and Figure 2 This demonstrates that the target product was successfully produced.

[0114] The molar ratio of tris(4-aminophenyl)amine to indomethacin anhydride is 1:3, and the amount of toluene used is 160 mL relative to 0.01 mol of tris(4-aminophenyl)amine.

[0115] The molar ratio of intermediate product A1 to polyisobutylene maleic anhydride is 1:3, and the amount of 150SN used is 0.625 mL relative to 1 mL of toluene.

[0116] Example 2

[0117] The cleaning and dispersing agent F2 was prepared using the following steps:

[0118] (1) Add 4.89 g (0.03 mol) indomethacin anhydride and 2.9 g (0.01 mol) tris(4-aminophenyl)amine to a 500 mL reactor, add 160 mL of toluene, purge with nitrogen, turn on the cooling water for reflux, and react at 80 °C for 12 hours. After the reaction is complete, rotary evaporate to remove toluene and obtain intermediate product A2.

[0119] (2) Add 33g of polyisobutylene maleic anhydride dissolved in 100mL of 150SN to intermediate product A2, purge with nitrogen, turn on the cooling water, and react at 160℃ for 5h. After the reaction is complete, evaporate by rotary evaporation to remove the solvent and obtain cleaning dispersant F2.

[0120] The molar ratio of tris(4-aminophenyl)amine to indomethacin anhydride is 1:3, and the amount of toluene used is 160 mL relative to 0.01 mol of tris(4-aminophenyl)amine.

[0121] The molar ratio of intermediate product A1 to polyisobutylene maleic anhydride is 1:3, and the amount of 150SN used is 0.625 mL relative to 1 mL of toluene.

[0122] Example 3

[0123] The cleaning and dispersing agent F3 was prepared using the following steps:

[0124] (1) Add 4.89 g (0.03 mol) indomethacin anhydride and 2.9 g (0.01 mol) tris(4-aminophenyl)amine to a 500 mL reactor, add 160 mL of toluene, purge with nitrogen, turn on the cooling water for reflux, and react at 100 °C for 8 hours. After the reaction is complete, remove the toluene by rotary evaporation to obtain intermediate product A3.

[0125] (2) Add 33g of polyisobutylene maleic anhydride dissolved in 100mL of 150SN to intermediate product A3, purge with nitrogen, turn on the cooling water, and react at 140℃ for 8h. After the reaction is completed, rotary evaporate to remove the solvent and obtain cleaning dispersant F3.

[0126] The molar ratio of tris(4-aminophenyl)amine to indomethacin anhydride is 1:3, and the amount of toluene used is 160 mL relative to 0.01 mol of tris(4-aminophenyl)amine.

[0127] The molar ratio of intermediate product A1 to polyisobutylene maleic anhydride is 1:3, and the amount of 150SN used is 0.625 mL relative to 1 mL of toluene.

[0128] Comparative Example 1

[0129] The method of Example 1 was used, except that only polyisobutylene maleimide was used to synthesize the polyisobutylene maleimide-type detergent dispersant, wherein the number average molecular weight of the polyisobutylene maleimide was 1000. The detergent dispersant DF1 of this comparative example was obtained.

[0130] Comparative Example 2

[0131] The method of Example 1 was used, except that indomethacin anhydride was not added. Tris(4-aminophenyl)amine and polyisobutylene maleic anhydride were reacted at a molar ratio of 1:3. The reaction conditions were as follows: 33g of polyisobutylene maleic anhydride (number average molecular weight of 1000) was dissolved in 100mL of 150SN and added to the reaction vessel. Then, 2.9g of tris(4-aminophenyl)amine was added, nitrogen gas was introduced, cooling water was turned on, the temperature was raised to 150°C, and the heating time was 6h. The reaction was then stopped. The detergent dispersant DF2 of this comparative example was obtained.

[0132] Comparative Example 3

[0133] The method of Example 1 was used, except that tris(4-aminophenyl)amine was replaced with an equimolar amount of diaminodiphenylmethane. The detergent-dispersant DF3 of this comparative example was obtained.

[0134] Examples 5-9

[0135] The cleaning and dispersing agents F1-F4 prepared in Examples 1-4 were added to a container according to the composition and proportion shown in Table 1, and stirred at 60°C for 2 hours to obtain scale inhibitor compositions A1-A5.

[0136] In Example 9, the antioxidant used was methyl 3,5-di-tert-butyl-4-hydroxyphenyl acrylate; the rust inhibitor was dodecenyl succinic acid.

[0137] Comparative Examples 4-6

[0138] The cleaning and dispersing agents DF1-DF3 prepared in Comparative Examples 1-3 were added to a container according to the composition and proportion shown in Table 1, and stirred at 60°C for 2 hours to obtain scale inhibitor compositions D1-D3.

[0139] Comparative Example 7

[0140] Without adding detergent and dispersant, the other components are added to the container according to the composition and proportion shown in Table 1, and stirred at 60°C for 2 hours to obtain scale inhibitor composition D4.

[0141] Test Examples 1-9

[0142] Simulated coking tests were conducted using L-1 type plate coking units with scale inhibitor compositions A1-A5 and D1-D4. The coking test conditions were: continuous operation, oil temperature 150℃, plate temperature 310℃, for 2 hours. After the test, the aluminum plates were placed at room temperature, immersed in gasoline and petroleum ether, dried, and weighed. The mass of the coked plate was obtained by subtracting its mass before the test from its mass after the test, and the scale inhibition efficiency was calculated. The results are listed in Table 1.

[0143] The dosage of the scale inhibitor composition is 1000 mg relative to 1 kg of crude oil. The parameters of the crude oil are listed in Table 2.

[0144] Wherein, scale inhibition efficiency = (m0-m1) / m0×100%;

[0145] m0 represents the mass of coke deposited on the aluminum plate without the scale inhibitor composition, in mg; m1 represents the mass of coke deposited on the aluminum plate with the scale inhibitor composition, in mg. A higher scale inhibition efficiency value indicates higher scale inhibition efficiency, meaning a better effect of the scale inhibitor composition.

[0146] Table 1

[0147]

[0148]

[0149] Table 2

[0150]

[0151] As shown in Table 1, the scale inhibitor composition of this disclosure has high descaling efficiency and good high-temperature resistance, making it suitable for processing high-acid, high-sulfur, and low-quality crude oil. Furthermore, a comparison between Examples 1-3 and Example 4 shows that when the content of the detergent-dispersant is within the optimal range, i.e., 13-20% by weight, the scale inhibitor composition prepared exhibits even higher scale inhibition efficiency.

[0152] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0153] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0154] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A scale inhibitor composition, characterized in that, The scale inhibitor composition comprises a diluent and a detergent-dispersant, the diluent containing a hydrocarbon substance with a boiling point of 180-410°C, and the detergent-dispersant having the structure shown in formula (1): Among them, R1, R2, R3 and R4 may be the same as or different from each other, and are independently selected from H, halogen groups, cyano groups and alkyl groups having 1-10 carbon atoms; n1 represents the number of R1s, n2 represents the number of R2s, n3 represents the number of R3s, and n4 represents the number of R4s; n1, n2, n3, and n4 may be the same as or different from each other, and are independently selected from 1, 2, 3, or 4 respectively; L is selected from a single bond or an alkylene group having 1-5 carbon atoms; PIB represents polyisobutylene.

2. The scale inhibitor composition according to claim 1, wherein, R1, R2, R3 and R4 are the same and are selected from H, halogen groups, cyano groups and alkyl groups having 1-10 carbon atoms; n1, n2 and n3 are the same and are selected from 1, 2, 3 or 4.

3. The scale inhibitor composition according to claim 1, wherein, R1, R2, R3, and R4 are each H, and L is a single bond.

4. The scale inhibitor composition according to claim 1, wherein, The cleaning and dispersing agent has the structure shown in formula (1-1):

5. The scale inhibitor composition according to claim 1, wherein, The diluent includes one or more of diesel oil, aviation kerosene, and heavy aromatics.

6. The scale inhibitor composition according to claim 1, wherein, The content of the detergent-dispersant is 1-30% by weight relative to the total weight of the scale inhibitor composition.

7. The scale inhibitor composition according to claim 1, wherein, The content of the detergent-dispersant is 5-25% by weight relative to the total weight of the scale inhibitor composition.

8. The scale inhibitor composition according to claim 1, wherein, The scale inhibitor composition further comprises an antioxidant, which includes one or more of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants and thiophenolic antioxidants; The antioxidant content is 0.05-2% by weight relative to the total weight of the scale inhibitor composition.

9. The scale inhibitor composition according to claim 1, wherein, The scale inhibitor composition further comprises a rust inhibitor, which includes one or more of petroleum sulfonates, imidazole compounds, imidazole-alkenyl succinate, alkenyl succinic acid, thiadiazole compounds, and alkenyl succinates. The content of the rust inhibitor is 0.1-5% by weight relative to the total weight of the scale inhibitor composition.

10. A method for preparing the scale inhibitor composition according to any one of claims 1-9, characterized in that, The method includes the following steps: S1 brings the first reactant and the second reactant into contact and react in the first solvent to obtain an intermediate product; S2 reacts the intermediate product and polyisobutylene maleic anhydride in a second solvent to obtain the detergent-dispersant. S3. Mix the cleaning and dispersing agent with the diluent; The first reactant has the structure shown in formula (2), and the second reactant has the structure shown in formula (3) or formula (4): R5 is selected from alkyl groups having 1-10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-10 carbon atoms, and substituted or unsubstituted aryl groups having 6-15 carbon atoms. The substituents in the substituted aryl and substituted cycloalkyl groups are each independently selected from one or more of deuterium, halogen groups, and alkyl groups having 1-5 carbon atoms.

11. The method according to claim 10, wherein, Additives are added in step S3.

12. The method according to claim 10, wherein, The second reactant is selected from one of indomethacin anhydride, 6-methylindomethacin, and 6,8-dibromoindomethacin anhydride; or, The second reactant is selected from one of pentane p-aminobenzoate, ethyl 2-aminobenzoate, menthol an-aminobenzoate, and benzyl p-aminobenzoate.

13. The method according to claim 10, wherein, The second reactant is indomethacin anhydride.

14. The method of claim 10, wherein, In step S1, the molar ratio of the first reactant to the second reactant is 1:(3-3.5); The reaction conditions include: a reaction temperature of 80-100℃, a reaction time of 8-12h, and the first solvent including one or more of toluene, benzene, and xylene.

15. The method according to claim 10, wherein, In step S1, the molar ratio of the first reactant to the second reactant is 1:(3-3.2).

16. The method of claim 10, wherein, In step S1, the reaction temperature is 85-95℃.

17. The method according to claim 10, wherein, In step S1, the reaction time is 9-10 hours.

18. The method according to claim 10, wherein, In step S1, the first solvent is toluene.

19. The method according to claim 10, wherein, In step S2, the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.5); The reaction conditions include: a reaction temperature of 140-160℃ and a reaction time of 4-8 hours; The polyisobutylene maleic anhydride has a number-average molecular weight of 800-2500, and the second solvent is a base oil.

20. The method of claim 10, wherein, In step S2, the molar ratio of the intermediate product to the polyisobutylene maleic anhydride is 1:(3-3.2).

21. The method according to claim 10, wherein, In step S2, the reaction temperature is 145-155℃.

22. The method according to claim 10, wherein, In step S2, the reaction time is 5-7 hours.

23. The method according to claim 10, wherein, The number-average molecular weight of the polyisobutylene maleic anhydride is 1000-2300.

24. The method according to claim 10, wherein, The second solvent is 150SN or white oil.

25. The method according to claim 10, wherein, In step S3, the mixing conditions include: a temperature of 20-60℃ and a time of 0.5-4h.

26. The method according to claim 11, wherein, The additives include antioxidants and / or rust inhibitors; The antioxidants include one or more of hindered phenolic antioxidants, amine antioxidants, phenolic ester antioxidants, and thiophenolic antioxidants; The rust inhibitor includes one or more of petroleum sulfonates, imidazole compounds, imidazole-linen-succinate, alkenyl succinic acid, thiadiazole compounds, and alkenyl succinates.

27. The use of the scale inhibitor composition according to any one of claims 1-9 in scale inhibition in crude oil processing equipment.

28. The application according to claim 27, wherein, The method for scale inhibition in the crude oil processing unit includes: mixing the scale inhibition composition with crude oil and then introducing it into the crude oil processing unit; the amount of the scale inhibition composition used is 100-1000 mg relative to 1 kg of crude oil; The crude oil has a sulfur content of 1.5-2.5% by weight and an acid value of 0.15-0.25 mg KOH / g; The crude oil processing unit includes pipelines and / or heat exchangers.

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