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CN-121976194-A - Schiff base type high-temperature high-pressure oxygen-containing CO2Corrosion inhibitor and preparation method thereof

CN121976194ACN 121976194 ACN121976194 ACN 121976194ACN-121976194-A

Abstract

The invention belongs to the technical field of corrosion inhibitors, and provides a Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor and a preparation method thereof. The corrosion inhibitor comprises a main agent, an auxiliary agent and a surfactant, wherein the main agent is naphthalene ring fluorine-containing Schiff base. The preparation method comprises mixing main agent, adjuvant and surfactant, and cleaning. The naphthalene nucleus fluorine-containing Schiff base is used as a main corrosion inhibition component, so that corrosion of carbon dioxide to metal can be effectively prevented under high-temperature and high-pressure environments, and the corrosion inhibition effect is further enhanced and the stability and corrosion inhibition performance of the corrosion inhibitor are improved by adding components such as a surfactant, an auxiliary agent and the like.

Inventors

  • JIANG SHUANG
  • WANG HUAIYUAN
  • WANG RUITAO
  • ZHANG XIAOOU
  • YUAN WENYING
  • HE XINLEI
  • MAO YUCHAO

Assignees

  • 天津大学浙江研究院
  • 天津大学

Dates

Publication Date
20260505
Application Date
20251219

Claims (10)

  1. 1. The Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor is characterized by comprising, by mass, 5-10% of a main agent, 2-6% of an auxiliary agent and 5-10% of a surfactant, wherein the main agent is naphthalene ring fluorine-containing Schiff base.
  2. 2. The schiff base type high-temperature and high-pressure oxygen-containing CO 2 corrosion inhibitor according to claim 1, wherein the main agent is at least one selected from the group consisting of N- (4-fluorophenyl) -1, 5-naphthalene diimine, N- (2-fluorophenyl) -1, 5-naphthalene diimine, N- (3-fluorophenyl) -1, 5-naphthalene diimine, N- (2, 4-difluorophenyl) -1, 5-naphthalene diimine, N- (4-fluorophenyl) -1, 8-naphthalene diimine, N- (2-fluorophenyl) -1, 8-naphthalene diimine and N- (4-fluoropyridin-2-yl) -1, 5-naphthalene diimine.
  3. 3. The Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor according to claim 2, wherein the main agent is selected from N- (4-fluorophenyl) -1, 5-naphthalene diimine, and the synthetic raw materials of the main agent comprise 3.5-4.0% of 1, 4-naphthalene diamine and 5-6% of 4-fluorobenzaldehyde by mass percent.
  4. 4. The schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor according to claim 1, wherein the auxiliary agent is at least one selected from sodium molybdate, sodium sulfite and thiourea.
  5. 5. The schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor according to claim 1, wherein the surfactant is at least one selected from sodium dodecyl sulfate, cetyltrimethylammonium bromide and sodium dodecyl benzene sulfonate.
  6. 6. The schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor according to claim 1, wherein the schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor further comprises 74-88% of an organic solvent, wherein the organic solvent is at least one of ethanol and N, N-dimethylformamide.
  7. 7. The method for preparing the Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor according to any one of claims 1 to 6, which is characterized by comprising the following steps: And mixing and cleaning the main agent, the auxiliary agent and the surfactant according to the corresponding mass percentages to obtain the Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor.
  8. 8. The method according to claim 7, further comprising the step of preparing the main agent before the mixing, wherein the main agent is obtained by adding a synthetic raw material of the main agent to an organic solvent and adding a catalyst.
  9. 9. The method according to claim 8, wherein the reaction temperature is 50 to 100 ℃; and/or the catalyst is at least one of glacial acetic acid, propionic acid, benzoic acid, formic acid, dilute hydrochloric acid, dilute sulfuric acid and phosphoric acid with the concentration of 5-8%.
  10. 10. The method according to claim 7, wherein the main agent, the auxiliary agent and the surfactant are mixed in an organic solvent.

Description

Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor and preparation method thereof Technical Field The disclosure relates to the technical field of corrosion inhibitors, in particular to a Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor and a preparation method thereof. Background In the industrial fields of oil gas exploitation, geothermal power generation and the like, the problem of corrosion of metal pipelines caused by the high-temperature high-pressure CO 2 environment is increasingly outstanding. Although the normal temperature CO 2 corrosion inhibitor (such as imidazolines, amines and quaternary ammonium salts) is widely used, the corrosion inhibitor is greatly failed due to the aggravation of molecular thermal motion and the rupture of chemical bonds at the temperature of more than 120 ℃. For example, the corrosion rate of the quaternary ammonium salt corrosion inhibitor disclosed in the prior art is as high as 0.45 mm/a under the condition of CO 2 of 150 ℃ per 2 MPa, and the requirements of deep well operation cannot be met. The development of high-temperature corrosion inhibitors faces two major bottlenecks, namely, firstly, the thermal stability is insufficient, the short-term temperature resistance of organic phosphonate is good, but the organic phosphonate is easy to decompose to produce calcium phosphate scale after long-term use, so that local corrosion is aggravated, secondly, the environmental compatibility is poor, the chromate corrosion inhibitor has the temperature resistance of more than 180 ℃, and the heavy metal toxicity violates environmental regulations. Therefore, it is necessary to provide a corrosion inhibitor which is highly stable in high temperature and high pressure environments. Disclosure of Invention The disclosure provides a Schiff base type high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor and a preparation method thereof, which at least solve the technical problems existing in the prior art. According to the first aspect of the disclosure, the high-temperature high-pressure oxygen-containing CO 2 corrosion inhibitor comprises, by mass, 5-10% of a main agent, 2-6% of an auxiliary agent and 5-10% of a surfactant, wherein the main agent is naphthalene ring fluorine-containing Schiff base. Specifically, the main agent is naphthalene ring fluorine-containing Schiff base, wherein the main agent comprises a naphthalene ring skeleton, fluorine-containing groups and a Schiff base (Schiff base) structure, the naphthalene ring skeleton can provide high thermal stability (the decomposition temperature is generally higher than 250 ℃) and large adsorption area, the adhesion capability of molecules on the metal surface is enhanced, the fluorine-containing groups utilize electronegativity and hydrophobicity of fluorine atoms to reduce the hydrophilicity of the metal surface, the erosion resistance is improved, meanwhile, the chemical stability of the molecules is enhanced, C=N double bonds in the Schiff base structure have strong coordination capability, and can form a chelating adsorption layer with Fe 2+ on the metal surface (experiments prove that the adsorption capability is higher than 180 kJ/mol), so that contact of corrosive media such as carbon dioxide and oxygen is blocked. According to the method, the Schiff base main agent is designed, and a compact erosion-resistant film layer is constructed on a metal interface by combining directional arrangement of the surfactant and auxiliary action of the auxiliary agent, so that the corrosion inhibition effect is greatly improved. In a preferred embodiment, the schiff base type high temperature and high pressure oxygen-containing CO 2 corrosion inhibitor comprises 8% of a main agent, 4% of an auxiliary agent and 8% of a surfactant in percentage by mass. In one embodiment, the main agent is selected from at least one of N- (4-fluorophenyl) -1, 5-naphthalene diimine, N- (2-fluorophenyl) -1, 5-naphthalene diimine, N- (3-fluorophenyl) -1, 5-naphthalene diimine, N- (2, 4-difluorophenyl) -1, 5-naphthalene diimine, N- (3, 5-difluorophenyl) -1, 5-naphthalene diimine, N- (4-fluorophenyl) -1, 8-naphthalene diimine, N- (2-fluorophenyl) -1, 8-naphthalene diimine, N- (4-fluoropyridin-2-yl) -1, 5-naphthalene diimine. In a preferred embodiment, the main agent is selected from N- (4-fluorophenyl) -1, 5-naphthalimide. Specifically, when the main agent is N- (4-fluorophenyl) -1, 5-naphthalimide, the synthetic raw materials of the main agent comprise 3.5-4.0% of 1, 4-naphthalene diamine and 5-6% of 4-fluorobenzaldehyde by mass percent. In one embodiment, the auxiliary agent is at least one selected from sodium molybdate, sodium sulfite and thiourea. Specifically, the core function of the main agent is to chelate the c=n double bond with the Fe 2+ on the metal surface, and the naphthalene ring and the fluorine group form a physical adsorption layer