WO2021026921A1 - Corrosion inhibitor and preparation method therefor, and method for inhibiting naphthenic acid corrosion in oil - Google Patents

Abstract

A corrosion inhibitor. In percentage by mass, raw materials for preparing the corrosion inhibitor comprise: an aromatic polyester: 25%-65%; a corrosion inhibition aid: 1%-40%; and an organic solvent: 20%-60%, wherein the aromatic polyester is selected from at least one of an aromatic polybasic acid ester and an aromatic polyphenol ester, the corrosion inhibition aid is selected from at least one of an olefin-maleic anhydride copolymer and an oil-soluble magnesium compound, and the oil-soluble magnesium compound is selected from at least one of oil-soluble nano-magnesium hydroxide and oil-soluble nano-magnesium oxide.

Description

Corrosion inhibitor, preparation method thereof and method for inhibiting naphthenic acid corrosion in oil Technical field

The invention relates to the field of crude oil refining, in particular to a corrosion inhibitor, a preparation method thereof, and a method for inhibiting naphthenic acid corrosion in oil products.

Background technique

With the continuous consumption of crude oil resources, crude oil prices continue to rise. In order to reduce the cost of raw materials, the research and development of processing technology that uses low-quality and cheap crude oil as raw materials to produce high value-added products has become the focus of attention of major international oil companies. The refining technology of low-priced high-acid crude oil has good application prospects and benefit expectations. However, the corrosion problem of naphthenic acid must be solved first when processing high-acid crude oil. At present, the methods for solving naphthenic acid corrosion can be divided into the following three types: First, use corrosion-resistant materials in oil refining equipment and equipment, and upgrade anti-corrosion materials; second, control the flow rate and flow state of crude oil processing, and improve oil refining The equipment structure is optimized and designed; third, process measures are adopted for anti-corrosion, such as crude oil mixing, crude oil deacidification, and adding corrosion inhibitors to easily corrosive parts. At present, adding corrosion inhibitors is the simplest and most effective solution to high-temperature naphthenic acid corrosion during the processing of high-acid crude oil.

Foreign research on the application of corrosion inhibitors to inhibit naphthenic acid corrosion has a history of nearly 50 years. Early amine corrosion inhibitors are easy to decompose at high temperatures, so they are gradually replaced by other agents. In recent years, with the deterioration of crude oil, The research of high-temperature naphthenic acid corrosion inhibitors has attracted more and more attention. At present, high-temperature corrosion inhibitors can be divided into phosphorus-containing corrosion inhibitors and non-phosphorus corrosion inhibitors. Phosphorus-containing high-temperature corrosion inhibitors are mainly composed of phosphate compounds. Although this type of corrosion inhibitor has excellent corrosion inhibition effects, it will cause high harm to hydrogenation catalysts, so its application is greatly restricted; phosphorus-free high-temperature corrosion inhibitors Mainly sulfur-containing and nitrogen-containing compounds, such as sulfonated nonylphenol, polysulfide, aminoamide, dihydroxyethylpiperazine, etc., these corrosion inhibitors have poor corrosion inhibition effects, which are difficult to meet the requirements of today's oil refining industry. demand.

Summary of the invention

Based on this, it is necessary to provide a corrosion inhibitor with good corrosion inhibition effect and low toxicity.

In addition, a method for preparing a corrosion inhibitor and a method for inhibiting naphthenic acid corrosion in oil products are also provided.

A corrosion inhibitor, in terms of mass percentage, the raw materials for preparing the corrosion inhibitor include:

Aromatic polyesters 25%-65%;

Corrosion-inhibiting additives 1%-40%; and

Organic solvents 20% to 60%;

Wherein, the aromatic polyester is selected from at least one of aromatic polybasic acid esters and aromatic polyphenol esters, and the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds. One type, the oil-soluble magnesium compound is selected from at least one of oil-soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide.

A preparation method of a corrosion inhibitor includes the following steps:

In terms of mass percentage, weigh the following raw materials: aromatic polyester 25%-65%, corrosion inhibitor 1%-40%, and organic solvent 20%-60%, wherein the aromatic polyester is selected from aromatics At least one of polybasic acid esters and aromatic polyphenol esters, the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds, and the oil-soluble magnesium compounds are selected from oils At least one of soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide; and

The aromatic polyester, the corrosion inhibitor and the organic solvent are mixed to obtain a corrosion inhibitor.

A method for inhibiting the corrosion of naphthenic acid in an oil product, comprising: adding a corrosion inhibitor to the oil product, and the raw materials for preparing the corrosion inhibitor include: 25%-65% of aromatic polyesters, by mass percentage, Corrosion inhibitor 1%-40%; and organic solvent 20%-60%; wherein, the aromatic polyester is selected from at least one of aromatic polybasic acid esters and aromatic polyphenol esters, and the corrosion inhibitor The auxiliary agent is selected from at least one of olefin-maleic anhydride copolymer and oil-soluble magnesium compound, and the oil-soluble magnesium compound is selected from at least one of oil-soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide.

The details of one or more embodiments of the present invention are set forth in the following description. Other features, objects, and advantages of the present invention will become apparent from the description and claims.

detailed description

In order to facilitate the understanding of the present invention, the following will describe the present invention more comprehensively in conjunction with specific embodiments. The preferred embodiments of the present invention are given in the detailed description. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention.

According to an embodiment of the corrosion inhibitor, in terms of mass percentage, the raw materials for preparing the corrosion inhibitor include: aromatic polyester 25%-65%, corrosion inhibitor 1%-40% and organic solvent 20%-60%. , The aromatic polyester is selected from at least one of aromatic polybasic acid esters and aromatic polyphenol esters, and the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds, oil-soluble The magnesium compound is selected from at least one of oil-soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide.

Among them, the aromatic polyester is an aromatic compound substituted by a monoester group, and there is at least one carboxyl group or hydroxyl group at other substitution positions of the aromatic polyether;

Alternatively, the aromatic polyester is an aromatic compound substituted with at least two ester groups. In some embodiments, when the aromatic polybasic ester is an aromatic compound substituted with at least two ester groups, there are no carboxyl groups or hydroxyl groups at other substitution positions of the aromatic polybasic ester. In other embodiments, when the aromatic polyester is an aromatic compound substituted with at least two ester groups, at least one carboxyl group or hydroxyl group exists at other substitution positions of the aromatic polyester.

The above-mentioned aromatic polyester contains at least two polar groups. In this embodiment, the polar group is an ester group, a hydroxyl group, or a carboxyl group. In some embodiments, the above-mentioned aromatic polyester contains at least two ester groups. In other embodiments, the above-mentioned aromatic polyester contains at least one ester group and at least one carboxyl group. In other embodiments, the aromatic polybasic acid ester contains at least one ester group and at least one hydroxyl group.

Wherein, the parent of the aromatic polyester is selected from at least one of benzene, naphthalene, biphenyl, pyrene, anthracene, phenanthrene, and perylene.

Aromatic polyesters are aromatic polybasic acid esters. The raw materials for preparing aromatic polybasic acid esters include aromatic polybasic acids and aliphatic compounds. Aromatic polybasic acids are selected from phthalic acid, trimellitic acid, pyromellitic acid and mellitic acid. , Naphthalene dicarboxylic acid, naphthalene tetracarboxylic acid, biphenyl tetracarboxylic acid, perylene tetracarboxylic acid, phthalic anhydride, pyromellitic dianhydride, trimellitic anhydride, naphthalic anhydride, naphthalene tetracarboxylic anhydride, biphenyl tetracarboxylic dianhydride, double At least one of phenol A dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride and perylene tetracarboxylic dianhydride, and the aliphatic compound is a fatty alcohol with a carbon chain length of 4-12, or , Aliphatic compounds are unsaturated olefins with a carbon chain length of 4-12.

Aromatic polyesters are aromatic polyphenol esters. The raw materials for preparing aromatic polyphenol esters include aromatic compounds containing multiple hydroxyl groups and fatty acids, or the raw materials for preparing aromatic polyphenol esters include aromatic compounds containing multiple hydroxyl groups And fatty acid anhydrides, the aromatic compound containing multiple hydroxyl groups is selected from at least one of benzenediol, benzenetriol, benzenehexaol, naphthalenediol, naphthalenetriol, bibenzenediol, and bibenzenetriol, fatty acid The carbon chain length is 4-12. Fatty acid anhydrides are derived from fatty acids with a carbon chain length of 4-12.

The function of the above-mentioned hydrocarbon groups with a carbon chain length of 4-12 is to provide non-polar groups to improve the solubility of aromatic polybasic esters in oils.

The above-mentioned aromatic polyesters contain multiple polar ester groups (or unreacted carboxyl groups or hydroxyl groups) and planar non-polar aromatic ring structures. These polar groups can interact with the atoms on the metal surface at high temperatures. Chelation forms a stable chelate, which is firmly adsorbed on the metal surface. The planar non-polar aromatic ring structure can evenly cover the metal surface, which can effectively isolate the corrosive substance naphthenic acid from contacting the metal surface. Aromatic rings have better thermal stability than other heterocyclic compounds (such as imidazolines), and are not easily decomposed at high temperatures to cause failure. Therefore, the aromatic polyester has excellent high temperature corrosion inhibition performance.

The organic solvent is selected from at least one of aromatic hydrocarbon solvents and aliphatic hydrocarbon solvents. Specifically, the organic solvent is selected from at least one of heavy aromatic hydrocarbons, mixed trimethylbenzene, liquid paraffin, mixed tetramethylbenzene, and coker wax oil.

In some embodiments, the corrosion inhibitor is an olefin-maleic anhydride copolymer, and among the raw materials for preparing the corrosion inhibitor, the mass percentage of the olefin-maleic anhydride copolymer is 1%-20%.

In other embodiments, the corrosion inhibitor is an oil-soluble magnesium compound, and the mass percentage of the oil-soluble magnesium compound in the raw materials for preparing the corrosion inhibitor does not exceed 20%.

Further, the corrosion inhibitor is a mixture of an olefin-maleic anhydride copolymer and an oil-soluble magnesium compound. In the raw materials for preparing the corrosion inhibitor, the mass percentage of the olefin-maleic anhydride copolymer is 1%-20%, which is oil-soluble The mass percentage of magnesium compounds does not exceed 20%. When the corrosion inhibitor is a mixture of olefin-maleic anhydride copolymer and oil-soluble magnesium compound, the obtained corrosion inhibitor has better corrosion inhibition effect.

The oil-soluble magnesium compound is obtained by modifying the nanometer magnesium compound so that the nanometer magnesium compound can be dissolved in an organic solvent. Specifically, the oil-soluble magnesium compound is selected from at least one of fatty acid modified nano magnesium oxide, fatty acid modified nano magnesium hydroxide, sulfonic acid modified nano magnesium oxide, and sulfonic acid modified nano magnesium hydroxide, Sulfonic acid is alkyl sulfonic acid or alkyl benzene sulfonic acid. Specifically, the fatty acid-modified nano-magnesium oxide and the fatty acid-modified nano-magnesium hydroxide are both Supermega E series products produced by Cestoil. Both the sulfonic acid-modified nano-magnesium oxide and sulfonic acid-modified nano-magnesium hydroxide are the Supermega S series products produced by Cestoil.

The above-mentioned oil-soluble magnesium compounds have ultra-high alkali values, which can effectively neutralize naphthenic acid in corrosive media, reduce the acid value of oil products, and inhibit the corrosion of equipment from high acid value oil products from the source. In addition, The oil-soluble nano-magnesium compound clusters can be adsorbed on the defects on the metal surface to strengthen the integrity of the protective film and prevent pitting corrosion of the metal.

The raw materials for preparing the olefin-maleic anhydride copolymer include maleic anhydride and olefin, and the olefin is selected from at least one of α-olefins, styrene and styrene derivatives having a carbon chain length of 8 to 32. Specifically, the olefin-maleic anhydride copolymer is selected from the group consisting of octene-1 olefins, olefin-maleic anhydride copolymers obtained by the reaction of styrene and maleic anhydride, α-olefins with a carbon chain length of 14-18, and methylbenzene The olefin-maleic anhydride copolymer obtained by the reaction of ethylene and maleic anhydride, the olefin-maleic anhydride copolymer obtained by the reaction of α-olefins with a carbon chain length of 18-22 and maleic anhydride, and those with a carbon chain length of 24-32 One of olefin-maleic anhydride copolymers obtained by reacting α-olefin with maleic anhydride.

The olefin-maleic anhydride copolymer skeleton has alternating non-polar aliphatic carbon chain segments and polar anhydride groups, which can also form a stable chelate with metal atoms. Compared with aromatic polyesters, olefin-maleic acid The acid anhydride skeleton has more polar groups, has a stronger chelating effect, and can withstand higher temperatures, which expands the temperature range of the corrosion inhibitor of this embodiment, especially when extremely high temperature corrosion inhibition is required. Furthermore, compared with aromatic polyesters, the aliphatic skeleton of olefin-maleic anhydride copolymers is softer, and can be deformed to fill the irregular voids left by the aromatic polyester film on the metal surface to minimize metal exposure Area, forming a denser protective film, further improving the corrosion inhibition effect.

The above corrosion inhibitor has at least the following advantages:

(1) Among the raw materials of the above corrosion inhibitor, the aromatic polybasic acid ester contains a plurality of polar ester groups (or unreacted carboxyl groups or hydroxyl groups) and a planar non-polar aromatic ring structure, which can pass through these polar The group chelate with the metal surface atoms at high temperature to form a stable chelate, which is firmly adsorbed on the metal surface. The planar non-polar aromatic ring structure can evenly cover the metal surface, which can effectively isolate the corrosive substance ring. The contact between alkanoic acid and the metal surface, and the aromatic ring has better thermal stability than other heterocyclic compounds (such as imidazoline), and it is not easy to decompose at high temperature to cause failure. Therefore, the aromatic polyester has excellent high temperature corrosion inhibition performance .

(2) Among the raw materials of the above corrosion inhibitor, the olefin-maleic anhydride copolymer skeleton has alternating non-polar aliphatic carbon chain segments and polar anhydride groups, which can also form stable chelate with metal atoms. Compared with aromatic polyesters, the olefin-maleic anhydride skeleton has more polar groups, has stronger chelating effect, and can withstand higher temperatures, which expands the temperature range of the corrosion inhibitor of this embodiment. Especially for occasions that require extremely high temperature corrosion inhibition. Furthermore, compared with aromatic polyesters, the aliphatic skeleton of olefin-maleic anhydride is softer, and can be deformed to fill the irregular gaps left by the aromatic polyester film on the metal surface to minimize the exposed area of the metal. A denser protective film is formed to further improve the corrosion inhibition effect.

(3) Among the raw materials of the above corrosion inhibitors, the oil-soluble magnesium compound has an ultra-high alkali value, which can effectively neutralize the naphthenic acid in the corrosive medium, reduce the acid value in the oil, and inhibit the high acid from the source Corrosion of oil products to equipment, on the other hand, the oil-soluble magnesium compound clusters can be adsorbed on the defects of the metal surface, strengthen the integrity of the protective film, and prevent pitting corrosion of the metal.

(4) The raw materials in the above corrosion inhibitors cooperate with each other and have a synergistic effect, so that the resulting corrosion inhibitor has good thermal stability and corrosion inhibition effect. It can not only form a stable and dense protective film on the metal surface, but also neutralize the oil. Therefore, it has excellent high temperature corrosion inhibition performance, and the corrosion inhibition effect is better than that when any one of the components is used alone in many cases.

(5) The raw materials of the above corrosion inhibitors are easily available and low in cost. There are no harmful elements such as P and Cl in the corrosion inhibitor, or S element. On the one hand, it is environmentally friendly and on the other hand, it avoids the subsequent processing process. It is a kind of high temperature corrosion inhibitor with a wide range of applications.

The preparation method of the corrosion inhibitor in one embodiment is a preparation method of the above-mentioned corrosion inhibitor, and includes the following steps:

Step S110: In terms of mass percentage, weigh the following raw materials: aromatic polyester 25%-65%, corrosion inhibitor 1%-40% and organic solvent 20%-60%, wherein the aromatic polyester is selected from aromatic At least one of polybasic acid esters and aromatic polyphenol esters, the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds, and the oil-soluble magnesium compounds are selected from oil-soluble nano-oxidizers At least one of magnesium and oil-soluble nano-magnesium hydroxide.

When the aromatic polybasic ester is an aromatic polybasic acid ester, the raw materials for preparing the aromatic polybasic acid ester include aromatic polybasic acids and aliphatic compounds. The aromatic polybasic acid is selected from phthalic acid, trimellitic acid, pyromellitic acid, and benzene. Hexacarboxylic acid, naphthalenedicarboxylic acid, naphthalenetetracarboxylic acid, biphenyltetracarboxylic acid, perylenetetracarboxylic acid, phthalic anhydride, pyromellitic dianhydride, trimellitic anhydride, naphthalic anhydride, naphthalenetetracarboxylic anhydride, biphenyltetracarboxylic dianhydride , At least one of bisphenol A dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride and perylene tetracarboxylic dianhydride, the aliphatic compound is a fatty alcohol with a carbon chain length of 4-12 Or, the aliphatic compound is an unsaturated olefin with a carbon chain length of 4-12.

Fatty alcohols are monohydric alcohols. Specifically, the fatty alcohol is at least one selected from monohydric fatty alcohols having a carbon chain length of 4-12.

The unsaturated olefin is at least one selected from alpha olefins having a carbon chain length of 4-12.

Specifically, in one of the embodiments, the preparation process of the aromatic polybasic acid ester includes: under the protection of nitrogen, the molar ratio of the aromatic polybasic acid and the fatty alcohol is at 80°C to 220°C. The next reaction is 3h-12h to obtain aromatic polybasic acid ester.

During the above reaction, at least one of a heteropoly acid catalyst and a water-carrying agent can also be added to increase the reaction rate. The ratio of the total mass of aromatic polybasic acid and fatty alcohol to the mass of heteropolyacid catalyst and water-carrying agent is 1:(0～0.1):(0～5).

The heteropolyacid catalyst is selected from at least one of a supported phosphotungstic acid catalyst and a supported phosphomolybdic acid catalyst. Specifically, the supported phosphotungstic acid catalyst is a mesoporous silica supported phosphotungstic acid catalyst, and the supported phosphomolybdic acid catalyst is a mesoporous silica supported phosphomolybdic acid catalyst. Further, the supported phosphotungstic acid catalyst is prepared according to patent CN103586076A. The preparation process of the supported phosphomolybdic acid catalyst is similar to the preparation process of the supported phosphotungstic acid catalyst, except that the phosphotungstic acid solution is replaced with a phosphomolybdic acid solution.

The heteropolyacid catalyst can catalyze the esterification reaction between aromatic polybasic acid and fatty alcohol, and increase the reaction rate.

The water-carrying agent is selected from at least one of benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, hexane, heptane, octane and decane. The above-mentioned water-carrying agent can discharge the water generated during the esterification reaction in time, thereby improving the conversion rate of the esterification reaction.

In another embodiment, the preparation process of the aromatic polybasic acid ester includes: taking aromatic polybasic acids and unsaturated olefins in a molar ratio of 1:1 to 1:6 as raw materials, and sulfonic acid type mesoporous molecular sieves as catalysts. Under the protection of nitrogen, the addition reaction is carried out for 6 hours to 24 hours at 80°C to 160°C and the reaction pressure of 0.1MPa to 2MPa to obtain the aromatic polybasic acid ester.

Specifically, the sulfonic acid type porous molecular sieve is prepared according to patent CN102924272A.

The organic solvent is selected from at least one of aromatic hydrocarbon solvents and aliphatic hydrocarbon solvents. Specifically, the organic solvent is selected from at least one of heavy aromatic hydrocarbons, mixed trimethylbenzene, liquid paraffin, mixed tetramethylbenzene, and coker wax oil.

When the aromatic polybasic ester is an aromatic polyphenol ester, the raw materials for preparing the aromatic polyphenol ester include aromatic compounds containing multiple hydroxyl groups and fatty acids, or the raw materials for preparing the aromatic polyphenol ester include aromatic compounds containing multiple hydroxyl groups. Group compounds and fatty acid anhydrides. The aromatic compound containing multiple hydroxyl groups is at least one selected from aromatic polyphenols. Specifically, the aromatic compound containing multiple hydroxyl groups is at least one selected from the group consisting of benzenediol, benzenetriol, benzenehexaol, naphthalenediol, naphthalenetriol, biphenyldiol, and biphenyltriol.

Fatty acids are monobasic acids. Specifically, the carbon chain length of fatty acids is 4-12.

Fatty acid anhydrides are derived from fatty acids with a carbon chain length of 4-12. Further, fatty acid anhydrides are acid anhydrides formed from fatty acids with the same or different carbon chain lengths of 4-12.

In one of the embodiments, the preparation process of the aromatic polyphenol ester includes: under the protection of nitrogen, the molar ratio of the aromatic compound containing polyhydroxyl group and the fatty acid is at 80°C to 220°C. React for 3h-12h to obtain aromatic polyphenol ester. Alternatively, the preparation process of the aromatic polyphenol ester includes: under the protection of nitrogen, the molar ratio of the aromatic compound containing the polyhydroxyl group and the fatty acid anhydride is reacted at 80℃～220℃ for 3h～12h. , To obtain aromatic polyphenol esters.

During the above reaction, at least one of a heteropoly acid catalyst and a water-carrying agent can also be added to increase the reaction rate. The ratio of the total mass of the polyhydroxy-containing aromatic compound and fatty acid to the mass of the heteropolyacid catalyst and the water-carrying agent is 1:(0～0.1):(0～5). Alternatively, the ratio of the total mass of the polyhydroxy-containing aromatic compound and fatty acid anhydride to the mass of the heteropolyacid catalyst and the water-carrying agent is 1:(0˜0.1):(0˜5).

The heteropolyacid catalyst is the same as the heteropolyacid catalyst used in the preparation process of the above-mentioned aromatic polybasic acid ester. The above heteropolyacid catalyst can catalyze the esterification reaction of aromatic compounds containing multiple hydroxyl groups with fatty acids or fatty acid anhydrides, thereby increasing the reaction rate.

The water-carrying agent is the same as the water-carrying agent used in the preparation process of the above-mentioned aromatic polybasic acid ester. The above-mentioned water-carrying agent can discharge the water generated during the esterification reaction in time, thereby improving the conversion rate of the esterification reaction.

Specifically, the oil-soluble magnesium compound is selected from at least one of fatty acid modified nano magnesium oxide, fatty acid modified nano magnesium hydroxide, sulfonic acid modified nano magnesium hydroxide and sulfonic acid modified nano magnesium oxide, Among them, sulfonic acid is alkyl sulfonic acid or alkyl benzene sulfonic acid.

The raw materials for preparing the olefin-maleic anhydride copolymer include maleic anhydride and olefin, and the olefin is selected from at least one of α-olefins, styrene and styrene derivatives having a carbon chain length of 8 to 32. Specifically, the olefin-maleic anhydride copolymer is selected from the group consisting of octene-1 olefins, olefin-maleic anhydride copolymers obtained by the reaction of styrene and maleic anhydride, α-olefins with a carbon chain length of 14-18, and methylbenzene The olefin-maleic anhydride copolymer obtained by the reaction of ethylene and maleic anhydride, the olefin-maleic anhydride copolymer obtained by the reaction of α-olefins with a carbon chain length of 18-22 and maleic anhydride, and those with a carbon chain length of 24-32 One of olefin-maleic anhydride copolymers obtained by reacting α-olefin with maleic anhydride.

Step S120: mixing the aromatic polyester, the corrosion inhibitor and the organic solvent to obtain the corrosion inhibitor.

Specifically, in the above step of mixing the aromatic polyester, the corrosion inhibitor and the organic solvent, the temperature is 20° C. to 80° C., and the time is 0.5 h to 5 h. After the step of mixing the aromatic polyester, the corrosion inhibitor and the organic solvent, the step of cooling and filtering is further included.

The production process of the above corrosion inhibitor is simple, the raw materials are cheap and easy to obtain, and it is easy for industrial production.

The method for inhibiting the corrosion of naphthenic acid in an oil product according to an embodiment includes: adding a corrosion inhibitor to the oil product. The corrosion inhibitor is the above-mentioned corrosion inhibitor or the corrosion inhibitor obtained by the above-mentioned preparation method of the corrosion inhibitor.

Specifically, in the step of adding the corrosion inhibitor to the oil product, the addition amount of the corrosion inhibitor is 5 ppm to 1000 ppm of the oil quality. Further, the added amount of the corrosion inhibitor is 7 ppm-30 ppm of the oil quality.

Specifically, in the step of adding the corrosion inhibitor to the oil product, the processing temperature of the oil product is 240°C to 480°C.

The above-mentioned corrosion inhibitor has high temperature corrosion inhibition effect and low toxicity, and can be used to inhibit the corrosion of naphthenic acid in oil.

The following is the specific embodiment part:

Example 1-1

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add phthalic acid (0.1mol), phthalic anhydride (0.1mol), n-butanol (0.2mol), supported phosphotungstic acid catalyst (4.62g) and water-carrying agent toluene (231g) into the reactor. Under the protection of nitrogen, the temperature was gradually raised to 120°C under stirring, and the temperature was kept for 6 hours. The water produced by the reaction was carried by toluene, and the product was filtered to remove the catalyst to obtain the aromatic polybasic acid ester A.

Example 1-2

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add pyromellitic dianhydride (0.1mol) and decanol (0.25mol) into the reactor, under nitrogen protection, gradually increase the temperature to 160℃ with stirring, keep it for 12h, and discharge the water produced by the reaction at the same time to obtain the aromatic polybasic acid ester B.

Example 1-3

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add mellitic acid (0.1mol), hexanol (0.6mol), supported phosphomolybdic acid catalyst (4.77g) and water-carrying agent xylene (238.5g) into the reactor, under nitrogen protection, and gradually increase the temperature to 140 under stirring ℃, heat preservation for 3h, the water produced by the reaction is carried by xylene, the product is filtered to remove the catalyst, and the aromatic polybasic acid ester C is obtained.

Example 1-4

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add naphthalenedicarboxylic acid anhydride (0.05mol), naphthalenedicarboxylic acid (0.1mol), decanol (0.3mol) and water-carrying agent tetramethylbenzene (78.9g) into the reactor, under nitrogen protection, and gradually increase the temperature to 220°C while stirring. After holding for 8 hours, the water produced by the reaction is carried out by tetramethylbenzene to obtain aromatic polybasic acid ester D.

Example 1-5

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add biphenyltetracarboxylic acid (0.05mol), biphenyltetracarboxylic dianhydride (0.05mol), perylenetetracarboxylic acid (0.05mol), perylenetetracarboxylic dianhydride (0.05mol), dodecanol (0.4mol) in the reactor With a supported phosphotungstic acid catalyst (4.38g), under nitrogen protection, the temperature is gradually increased to 180°C under stirring, and the temperature is kept for 7 hours. At the same time, the water produced by the reaction is discharged. The product is filtered to remove the catalyst to obtain the aromatic polybasic acid ester E.

Example 1-6

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add benzophenone tetraacid dianhydride (0.05mol), diphenyl ether tetraacid dianhydride (0.05mol), bisphenol A dianhydride (0.1mol), butanol (0.6mol), supported type in the reactor Phosphomolybdic acid catalyst (1.28g) and cyclohexane (256g), protected by nitrogen, gradually increase the temperature to 80°C under stirring, keep for 5h, and drain the water produced by the reaction. The product is filtered to remove the catalyst to obtain the aromatic polybasic acid ester F .

Example 1-7

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add naphthalenetetracarboxylic acid anhydride (0.1mol), hexanol (0.2mol) and octanol (0.1mol) into the reactor, under nitrogen protection, gradually increase the temperature to 105°C under stirring, keep it for 12h, and discharge the water produced by the reaction at the same time. Aromatic polybasic acid ester G.

Let M1 represent the molar ratio of aromatic polybasic acid to fatty alcohol, m1 represents the total mass ratio of aromatic polybasic acid and fatty alcohol to the mass ratio of the catalyst and water-carrying agent, T1 represents the reaction temperature, and t1 represents the reaction time. Example 1 The parameters in the preparation process of the aromatic polybasic acid esters in -1 to Examples 1-7 are listed in Table 1.

Table 1 Parameters in the preparation process of aromatic polybasic acid esters in Examples 1-1 to 1-7

Example 1-8

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add pyromellitic acid (0.1mol), butene (0.3mol) and sulfonic acid type mesoporous molecular sieve catalyst (0.84g) into the reaction vessel. The reaction pressure is 1MPa. The temperature is gradually raised to 80°C under stirring and kept for 24h. The product is separated After removing the catalyst, an aromatic polybasic acid ester H is obtained.

Example 1-9

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add mellitic acid (0.1mol), octene (0.4mol), decene (0.2mol) and sulfonic acid type mesoporous molecular sieve catalyst (5.35g) into the reaction vessel, the reaction pressure is 1.5MPa, and the temperature is gradually increased to 160 under stirring After keeping the temperature at ℃ for 6h, the product is separated and the catalyst is removed to obtain the aromatic polybasic acid ester I.

Example 1-10

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add trimellitic acid (0.05mol), trimellitic anhydride (0.05mol), pentene (0.05mol), hexene (0.1mol) and sulfonic acid type mesoporous molecular sieve catalyst (4.80g) into the reaction vessel, the reaction pressure is 0.1 MPa, the temperature is gradually raised to 120°C with stirring, and the temperature is kept for 15 hours. After the product is separated, the catalyst is removed to obtain the aromatic polybasic acid ester J.

Example 1-11

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add naphthalenetetracarboxylic acid (0.1mol), dodecene (0.4mol) and sulfonic acid type mesoporous molecular sieve catalyst (9.80g) into the reaction vessel, the reaction pressure is 0.5MPa, and the temperature is gradually increased to 140℃ with stirring, and the product is kept for 12h. After separation, the catalyst is removed to obtain the aromatic polybasic acid ester K.

Example 1-12

The preparation process of the aromatic polybasic acid ester of this embodiment is as follows:

Add biphenyl tetracarboxylic acid (0.1 mol), butene (0.25 mol) and sulfonic acid type mesoporous molecular sieve catalyst (2.35 g) into the reaction vessel. The reaction pressure is 0.8 MPa. Under stirring, the temperature is gradually raised to 130° C., and the product is kept for 18 hours. After separation, the catalyst is removed to obtain the aromatic polybasic acid ester L.

M2 is the molar ratio of aromatic polybasic acid to unsaturated olefin, m2 is the ratio of the total mass of aromatic polybasic acid and unsaturated olefin to the amount of catalyst, T2 is the reaction temperature, t2 is the reaction time, and P1 is the reaction pressure. The parameters in the preparation process of the aromatic polybasic acid esters in Examples 1-8 to 1-12 are listed in Table 2.

Table 2 Parameters in the preparation process of aromatic polybasic acid esters in Examples 1-8 to 1-12

Example 1-13

The preparation process of the aromatic polyphenol ester of this embodiment is as follows:

Add benzenediol (0.2mol), dodecanoic acid (0.3mol), supported phosphomolybdic acid catalyst (8.2g) and water-carrying agent mixed with trimethylbenzene (410g) into the reactor, and under nitrogen protection, the temperature is gradually raised to After heating at 220°C for 3 hours, the water produced by the reaction was carried by the mixed trimethylbenzene, the product was filtered to remove the catalyst, and the aromatic polyphenol ester M was obtained.

Example 1-14

The preparation process of the aromatic polyphenol ester of this embodiment is as follows:

Add pyrogallol (0.05mol), benzenehexaol (0.15mol), butyric anhydride (0.4mol) and water-carrying agent xylene (287g) into the reactor, under nitrogen protection, gradually increase the temperature to 160℃ with stirring, and keep it for 8h , The water produced by the reaction is carried by xylene to obtain aromatic polyphenol ester N.

Example 1-15

The preparation process of the aromatic polyphenol ester of this embodiment is as follows:

Add naphthalenediol (0.1mol), naphthalenetriol (0.1mol), capric anhydride (0.2mol) and water-carrying agent cyclohexane (395g) into the reactor. Under nitrogen protection, gradually increase the temperature to 80°C under stirring, and keep warm. 12h, the water produced by the reaction is carried by cyclohexane to obtain aromatic polyphenol ester O.

Example 1-16

The preparation process of the aromatic polyphenol ester of this embodiment is as follows:

Add biphenyldiol (0.05mol), biphenyltriol (0.05mol), n-butyric acid (0.1mol), n-hexanoic acid (0.1mol), supported phosphotungstic acid catalyst (2g), nitrogen protection in the reactor , Gradually increase the temperature to 140°C under stirring, keep the temperature for 10 hours, and discharge the water produced by the reaction. The product is filtered to remove the catalyst, and the aromatic polyphenol ester P is obtained.

Example 1-17

The preparation process of the aromatic polyphenol ester of this embodiment is as follows:

Add benzenehexaol (0.05mol), capric acid (0.3mol) and water-carrying agent toluene (301g) into the reactor, under nitrogen protection, gradually increase the temperature to 160℃ with stirring, keep for 9h, the water produced by the reaction is carried by toluene , The aromatic polyphenol ester Q is obtained.

M3 represents the molar ratio of the aromatic compound containing multiple hydroxyl groups to the fatty acid (or fatty acid anhydride), and m3 represents the total mass of the aromatic compound containing multiple hydroxyl groups and the fatty acid (or fatty acid anhydride) and the mass of the catalyst and water-carrying agent. Ratio, T3 represents the reaction temperature, t3 represents the reaction time, the various parameters in the preparation process of the aromatic polyphenol esters in Examples 1-13 to 1-17 are listed in Table 3.

Table 3 Parameters in the preparation process of aromatic polyphenol esters in Examples 1-13 to 1-17

Comparative example 1-1

Add benzoic acid (0.1mol), benzoic anhydride (0.05mol), n-butanol (0.2mol), supported phosphotungstic acid catalyst (3.83g) and water-carrying agent toluene (191.5g) into the reactor, protected by nitrogen Under stirring, the temperature was gradually raised to 120°C and kept for 6 hours. The water produced by the reaction was carried by toluene. The product was filtered to remove the catalyst to obtain the aromatic monobasic acid ester R.

Comparative example 2

Add benzenediacetic acid (0.05mol), trimellitic acid (0.05mol), heptene (0.15mol), nonene (0.05mol) and sulfonic acid type mesoporous molecular sieve catalyst (0.21g) into the reaction vessel, and the reaction pressure is 2MPa , Gradually raise the temperature to 100°C under stirring and keep it for 8 hours. After the product is separated, the catalyst is removed to obtain the aromatic polybasic acid ester S.

The aromatic polybasic acid esters (A to L) prepared in Examples 1-1 to 1-12 or the aromatic polyphenol esters (M to 1) prepared in Examples 1-13 to 1-17 Q) After mixing with oil-soluble magnesium compounds (Ⅰ, Ⅱ, Ⅲ, Ⅳ), olefin-maleic anhydride copolymers (a, b, c, d) and organic solvents, stir them at 50℃ for 2h and then cool Filter to obtain corrosion inhibitor. The components and their mass percentages of the corrosion inhibitors prepared in Examples 2-1 to 2-18 are shown in Table 4.

Among them, oil-soluble magnesium compound I is fatty acid-modified nano-magnesium oxide, oil-soluble magnesium compound II is sulfonic acid-modified nano-magnesium oxide, and oil-soluble magnesium compound III is fatty acid-modified nano-magnesium hydroxide, an oil-soluble magnesium compound Ⅳ is sulfonic acid modified nanometer magnesium hydroxide.

Olefin-maleic anhydride copolymer a is an olefin-maleic anhydride copolymer obtained by the reaction of octene-1 olefin, styrene and maleic anhydride; olefin-maleic anhydride copolymer b is an α with a carbon chain length of 14-18 -Olefin-maleic anhydride copolymer obtained by reacting olefin, methyl styrene and maleic anhydride; olefin-maleic anhydride copolymer c is an olefin obtained by reacting an α-olefin with a carbon chain length of 18-22 and maleic anhydride -Maleic anhydride copolymer; the olefin-maleic anhydride copolymer d is an olefin-maleic anhydride copolymer obtained by reacting an α-olefin with a carbon chain length of 24-32 and maleic anhydride.

Table 4 Each component and content of corrosion inhibitor in each embodiment and comparative example

The corrosion inhibitors prepared in Example 2-1 to Example 2-18, Comparative Example 2-1 to Comparative Example 2-6 and the commercial corrosion inhibitors were tested for their corrosion inhibition performance. The results are shown in Table 5, respectively. Table 6 shows.

Among them, the decompression simulated static metal test piece weight loss method is used to test the corrosion inhibition performance. In a 500mL three-necked flask, add 250g of refined naphthenic acid to reduce the line oil corrosive medium (acid value 11.3mg KOH/g). Add the corrosion inhibitor of the test concentration and shake evenly. Install the vacuum distillation device, and keep the relative vacuum pressure of -0.08MPa and the temperature of 125±5℃ constant for 30 minutes to remove the moisture and volatile components in the corrosive medium.

The vertical condenser tube of the aforementioned vacuum distillation device was changed to a vacuum simulation test device. Soak the 20# carbon steel test piece that has been cleaned and accurately weighed in the corrosive medium. Adjust the relative vacuum pressure to -0.08MPa, keep it at different temperatures (240°C, 360°C, 480°C) for 6 hours and then cool it down to below 100°C, stop the test. Take out the test piece to observe the surface condition, and calculate the corrosion rate V and the corrosion inhibition rate I according to the weight loss of the test piece. Calculated as follows:

I=(V ₀ -V)/V ₀ *100%

Where: V ₀ is the corrosion rate of metal without corrosion inhibitor, mm/a;

V is the corrosion rate of metal when corrosion inhibitor is added, mm/a.

Among them, the calculation formula of the corrosion rate V is as follows:

V=(87600*△W)/(S*t*ρ)

In the formula: △W is the poor quality of the test piece before and after the test, g;

S is the effective surface area of the test piece, cm ² ;

t is the corrosion test time, h;

ρ is the density of the corrosion test piece, and carbon steel is calculated at 7.86g/cm ³ .

Table 5 Corrosion inhibition rate of corrosion inhibitor at different dosages at a corrosion temperature of 360℃

To	Corrosion inhibition rate (%)

Plus dose	5ppm	15ppm	30ppm	100ppm
Example 2-1	55.2	70.5	93.0	93.3
Example 2-2	61.8	81.0	95.8	97.2
Example 2-3	82.8	95.7	99.5	99.5
Example 2-4	72.6	87.4	91.5	92.4
Example 2-5	83.2	96.6	99.8	99.9
Example 2-6	64.5	77.0	80.5	81.4
Example 2-7	81.4	93.3	97.2	98.1
Example 2-8	70.0	81.6	90.5	90.6
Example 2-9	76.9	89.3	93.8	94.2
Example 2-10	79.7	91.4	95.0	95.3
Example 2-11	83.5	94.7	99.8	99.8
Example 2-12	83.6	94.5	98.5	98.5
Example 2-13	77.4	88.2	93.1	93.8
Example 2-14	78.8	87.0	93.6	93.9
Example 2-15	72.5	85.7	90.7	91.5
Example 2-16	76.3	86.8	92.6	93.3
Example 2-17	77.2	87.1	91.6	92.7
Example 2-18	78.2	89.1	94.7	95.0
Comparative example 2-1	20.8	35.9	59.7	67.8
Comparative example 2-2	60.8	71.3	82.9	83.1
Comparative example 2-3	24.2	45.1	47.6	48.1

Comparative example 2-4	25.6	48.3	49.2	49.1
Comparative example 2-5	34.2	56.8	57.7	58.3
Comparative example 2-6	19.4	31.8	54.3	66.2
Commercially available phosphorus-containing corrosion inhibitor	60.5	74.6	85.4	85.6
Commercially available non-phosphorus corrosion inhibitor	34.3	50.2	53.8	55.7

Table 6 The dosage of corrosion inhibitor is 15ppm, and the corrosion inhibition rate at different corrosion temperatures

Among them, the commercially available phosphorus-containing corrosion inhibitor is MN-HSⅢ type high temperature corrosion inhibitor produced by Weifang Mien Chemical Co., Ltd., and the commercially available non-phosphorus corrosion inhibitor is BXH-103 type phosphorus-free high temperature corrosion inhibitor produced by Hubei Benxin Technology Agent.

It can be seen from Table 5 that under the condition of a corrosion temperature of 360°C, the corrosion inhibition effect of the commercially available phosphorus-containing high-temperature corrosion inhibitor is significantly better than that of the non-phosphorus high-temperature corrosion inhibitor. Examples 2-2 to 2-3 , The high-temperature corrosion inhibitors prepared in Examples 2-5 to 2-18 are better than commercially available phosphorus-containing high-temperature corrosion inhibitors at the same dosage, especially in Examples 2-3 and 2 -5. The corrosion inhibition rate of the corrosion inhibitor of embodiment 2-11 can reach more than 99% when the dosage is 30ppm. Even when the dosage is 5ppm, the corrosion inhibition rate can reach more than 82%. The high temperature corrosion inhibitor has excellent corrosion inhibition performance at a lower dosage.

The corrosion inhibition performance of the high temperature corrosion inhibitor prepared in Example 2-1 is slightly lower than that of commercially available phosphorus-containing corrosion inhibitors at low dosages, because the high temperature corrosion inhibitor prepared in Example 2-1 is effective The component content is relatively low, and its corrosion inhibition performance is also better than that of commercially available phosphorus-containing corrosion inhibitors at a relatively high dosage.

The effect of the high temperature corrosion inhibitor prepared in Comparative Example 2-3 is worse than that of commercially available phosphorus-containing and non-phosphorus corrosion inhibitors, because the aromatic polyester is not added in Comparative Example 2-3, and the aromatic polyester is a corrosion inhibitor It is the most critical component in the high temperature corrosion inhibitor, which directly determines the performance of high temperature corrosion inhibitor.

The effects of the high-temperature corrosion inhibitors prepared in Comparative Example 2-1 and Comparative Example 2-2 are far lower than those of the high-temperature corrosion inhibitors prepared in Examples 2-6 and 2-9, respectively, and compared with those in Examples 2-6 and 2-6. The difference between Examples 2-9 is that Comparative Example 2-1 and Comparative Example 2-2 do not contain olefin-maleic anhydride copolymer, which shows that olefin-maleic anhydride copolymer also plays a key role in high temperature corrosion inhibitors. Function, even if a small amount of olefin-maleic anhydride copolymer (1wt%) is added to the high temperature corrosion inhibitor, the effect of the high temperature corrosion inhibitor will be qualitatively improved. In addition, the corrosion inhibition rate of Comparative Example 2-1 was lower when the dosage was 30ppm, and did not reach saturation, while the corrosion inhibition rate of Example 2-6 was higher when the dosage was 30ppm. It is close to saturation, indicating that the addition of olefin-maleic anhydride copolymer can greatly reduce the use of high temperature corrosion inhibitors.

The high temperature corrosion inhibitor prepared in Comparative Example 2-4 is not as effective as the high temperature corrosion inhibitor prepared in Examples 2-1 to 2-18, because the main corrosion inhibitor used in Comparative Example 2-4 has no carboxyl group or Hydroxyl-substituted aromatic monobasic esters cannot form complexes with metal ions, and are difficult to adsorb on the metal surface to form a stable protective film.

The effect of the high-temperature corrosion inhibitor prepared in Comparative Example 2-5 is not as good as the high-temperature corrosion inhibitor prepared in Examples 2-1 to 2-18, because the main corrosion inhibitor used in Comparative Example 2-5 is the aromatic polyester The ester group in the aromatic compound does not directly replace the hydrogen atoms on the aromatic compound. There will be a certain gap during film formation, which reduces the coverage of the metal surface.

Comparative example 2-6 uses trioctyl trimellitate as high temperature corrosion inhibitor. Under the condition of this dosage, its corrosion inhibition effect is not much different from that of comparative example 2-1, which is not as good as that of Examples 2-1 to Examples. 2-18 prepared high temperature corrosion inhibitor.

The effect of the high temperature corrosion inhibitor prepared in Example 2-8 is obviously inferior to that of the high temperature corrosion inhibitor prepared in Example 2-7, because the high temperature corrosion inhibitor prepared in Example 2-8 does not contain oil-soluble nano-magnesium In this system, the oil-soluble nano-magnesium compound, aromatic polyester and olefin-maleic anhydride copolymer have a certain complementary effect in the high-temperature corrosion inhibitor of the system. The use of the three together can achieve the best corrosion inhibition effect.

It can be seen from Table 6 that with the increase of the corrosion temperature, the corrosion inhibition rate of various corrosion inhibitors has decreased, especially the commercially available non-phosphorus high temperature corrosion inhibitor is the most obvious, because of its effective components Prone to decomposition at high temperatures. However, the corrosion inhibition rate of the high temperature corrosion inhibitors prepared in Examples 2-1 to 2-18 decreases slightly with the increase of temperature, and the degree of reduction in the corrosion inhibition rate is lower than that of the commercially available phosphorus-containing high temperature corrosion inhibitors This indicates that the corrosion inhibitor prepared in the examples has excellent high temperature resistance.

In summary, the corrosion inhibitor prepared in the above-mentioned embodiments has the advantages of low dosage and good effect. In addition, the raw materials used in the corrosion inhibitor prepared in the above-mentioned embodiments are simple and easy to obtain, the process is simple, and the cost is low. The corrosion inhibitor does not contain harmful elements such as phosphorus, sulfur, chlorine, and has good chemical stability at high temperatures, and will not adversely affect catalyst poisoning caused by subsequent processing. Therefore, the corrosion inhibitor prepared in the above embodiment has Broad application prospects.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several embodiments of the present invention, and the descriptions are more specific and detailed, but they should not be understood as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (20)

1. A corrosion inhibitor, in terms of mass percentage, the raw materials for preparing the corrosion inhibitor include:

   Aromatic multi-esters 25%-65%;

   Corrosion inhibitors 1%-40%; and

   Organic solvents 20%-60%;

   Wherein, the aromatic polyester is selected from at least one of aromatic polybasic acid esters and aromatic polyphenol esters, and the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds. One type, the oil-soluble magnesium compound is selected from at least one of oil-soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide.
2. The corrosion inhibitor of claim 1, wherein the aromatic polyester is an aromatic compound substituted by a monoester group, and one of a carboxyl group and a hydroxyl group is present at other substitution positions of the aromatic polyester Kind.
3. The corrosion inhibitor of claim 1, wherein the aromatic polyester is an aromatic compound substituted with at least two ester groups.
4. The corrosion inhibitor according to claim 2 or 3, wherein the parent of the aromatic polyester is selected from at least one of benzene, naphthalene, biphenyl, pyrene, anthracene, phenanthrene and perylene.
5. The corrosion inhibitor according to any one of claims 1 to 3, wherein the aromatic polybasic ester is an aromatic polybasic acid ester, and the raw materials for preparing the aromatic polybasic acid ester include aromatic polybasic acids and fatty acids. Family compound, the aromatic polybasic acid is selected from the group consisting of phthalic acid, trimellitic acid, pyromellitic acid, mellitic acid, naphthalene dicarboxylic acid, naphthalene tetracarboxylic acid, biphenyl tetracarboxylic acid, perylene tetracarboxylic acid, phthalic anhydride, Pyromellitic dianhydride, trimellitic anhydride, naphthalene dicarboxylic anhydride, naphthalene tetracarboxylic anhydride, biphenyl tetracarboxylic dianhydride, bisphenol A dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride and At least one of perylene tetracarboxylic dianhydride, and the aliphatic compound is a fatty alcohol with a carbon chain length of 4-12.
6. The corrosion inhibitor according to any one of claims 1 to 3, wherein the aromatic polybasic ester is an aromatic polybasic acid ester, and the raw materials for preparing the aromatic polybasic acid ester include aromatic polybasic acids and fatty acids. Family compound, the aromatic polybasic acid is selected from the group consisting of phthalic acid, trimellitic acid, pyromellitic acid, mellitic acid, naphthalene dicarboxylic acid, naphthalene tetracarboxylic acid, biphenyl tetracarboxylic acid, perylene tetracarboxylic acid, phthalic anhydride, Pyromellitic dianhydride, trimellitic anhydride, naphthalene dicarboxylic anhydride, naphthalene tetracarboxylic anhydride, biphenyl tetracarboxylic dianhydride, bisphenol A dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride and At least one of perylene tetracarboxylic dianhydride, and the aliphatic compound is an unsaturated olefin with a carbon chain length of 4-12.
7. The corrosion inhibitor according to any one of claims 1 to 3, wherein the aromatic compound is an aromatic polyphenol ester, and the raw material for preparing the aromatic polyphenol ester includes an aromatic compound containing multiple hydroxyl groups. Substances and fatty acids, the aromatic substance containing multiple hydroxyl groups is selected from at least one of benzenediol, benzenetriol, benzenehexaol, naphthalenediol, naphthalenetriol, biphenyldiol and biphenyltriol , The carbon chain length of the fatty acid is 4-12.
8. The corrosion inhibitor according to any one of claims 1 to 3, wherein the aromatic compound is an aromatic polyphenol ester, and the raw material for preparing the aromatic polyphenol ester includes an aromatic compound containing multiple hydroxyl groups. Substances and fatty acid anhydrides, the aromatic substances containing multiple hydroxyl groups are selected from at least one of benzenediol, benzenetriol, benzenehexaol, naphthalenediol, naphthalenetriol, biphenyldiol, and biphenyltriol Kind.
9. The corrosion inhibitor of claim 1, wherein the corrosion inhibitor is the olefin-maleic anhydride copolymer, and in the raw material for preparing the corrosion inhibitor, the olefin-maleic anhydride copolymer is The mass percentage of the substance is 1%-20%.
10. The corrosion inhibitor according to claim 1, wherein the corrosion inhibitor is a mixture of the olefin-maleic anhydride copolymer and the oil-soluble magnesium compound, and is used in the raw material for preparing the corrosion inhibitor. The mass percentage of the olefin-maleic anhydride copolymer is 1%-20%, and the mass percentage of the oil-soluble magnesium compound does not exceed 20%.
11. The corrosion inhibitor according to claim 1 or 10, wherein the oil-soluble magnesium compound is selected from the group consisting of fatty acid-modified nano-magnesium oxide, fatty acid-modified nano-magnesium hydroxide, and sulfonic acid-modified nano-hydroxide At least one of magnesium and sulfonic acid-modified nano-magnesium oxide, and the sulfonic acid is selected from one of alkyl sulfonic acid and alkyl benzene sulfonic acid.
12. The corrosion inhibitor according to claim 1, 9, or 10, wherein the raw materials for preparing the olefin-maleic anhydride copolymer include olefins and maleic anhydride, and the olefins are selected from carbon chain lengths of 8 to 32 At least one of α-olefins, styrene and styrene derivatives.
13. The corrosion inhibitor according to claim 12, wherein the olefin-maleic anhydride copolymer is selected from the group consisting of octene-1 olefin, olefin-maleic anhydride copolymer obtained by the reaction of styrene and maleic anhydride, carbon Alpha-olefins with a chain length of 14-18, olefin-maleic anhydride copolymers obtained by the reaction of methyl styrene and maleic anhydride, olefins obtained by the reaction of α-olefins with a carbon chain length of 18-22 and maleic anhydride- One of maleic anhydride copolymers and olefin-maleic anhydride copolymers obtained by reacting an α-olefin with a carbon chain length of 24-32 and maleic anhydride.
14. A preparation method of a corrosion inhibitor includes the following steps:

    In terms of mass percentage, weigh the following raw materials: aromatic polyester 25%-65%, corrosion inhibitor 1%-40%, and organic solvent 20%-60%, wherein the aromatic polyester is selected from aromatics At least one of polybasic acid esters and aromatic polyphenol esters, the corrosion inhibitor is selected from at least one of olefin-maleic anhydride copolymers and oil-soluble magnesium compounds, and the oil-soluble magnesium compounds are selected from oils At least one of soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide; and

    The aromatic polyester, the corrosion inhibitor and the organic solvent are mixed to obtain a corrosion inhibitor.
15. The method for preparing a corrosion inhibitor according to claim 14, wherein the preparation process of the aromatic polybasic acid ester comprises: under the protection of nitrogen, the molar ratio of the aromatic polybasic acid is 1:1 to 1:6. Acid and fatty alcohol react at 80℃～220℃ for 3h～12h to obtain aromatic polybasic acid ester.
16. The preparation method of the corrosion inhibitor according to claim 14, wherein the preparation process of the aromatic polybasic acid ester comprises: the aromatic polybasic acid and the unsaturated olefin in a molar ratio of 1:1 to 1:6 As the raw material, the sulfonic acid type mesoporous molecular sieve is used as the catalyst. Under the protection of nitrogen, the addition reaction is carried out at 80℃～160℃ and the reaction pressure of 0.1MPa～2MPa for 6h-24h to obtain the aromatic polybasic acid ester.
17. A method for inhibiting the corrosion of naphthenic acid in an oil product, comprising: adding a corrosion inhibitor to the oil product, and the raw materials for preparing the corrosion inhibitor include: 25%-65% of aromatic polyesters, by mass percentage, Corrosion inhibitor 1%-40%; and organic solvent 20%-60%; wherein, the aromatic polyester is selected from at least one of aromatic polybasic acid esters and aromatic polyphenol esters, and the corrosion inhibitor The auxiliary agent is selected from at least one of olefin-maleic anhydride copolymer and oil-soluble magnesium compound, and the oil-soluble magnesium compound is selected from at least one of oil-soluble nano-magnesium oxide and oil-soluble nano-magnesium hydroxide.
18. The method for inhibiting naphthenic acid corrosion in oil products according to claim 17, wherein in the step of adding a corrosion inhibitor to the oil product, the amount of the corrosion inhibitor added is the oil product 5ppm～1000ppm of mass.
19. The method for inhibiting naphthenic acid corrosion in oil products according to claim 18, characterized in that, in the step of adding a corrosion inhibitor to the oil product, the amount of the corrosion inhibitor added is the oil product 7ppm～30ppm of mass.
20. The method for inhibiting naphthenic acid corrosion in oil products according to claim 17, characterized in that in the step of adding corrosion inhibitors to the oil products, the processing temperature of the oil products is 240°C to 480°C.