阅读说明：本技术 一种抗稀盐酸和硫化氢腐蚀的炼油蒸馏塔顶缓蚀剂 (Oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide ) 是由 范磊 尹成先 杜笑怡 张娟涛 王峰 王延海 赵儒盼 袁军涛 于 2020-05-06 设计创作，主要内容包括：本发明公开了一种抗稀盐酸和硫化氢腐蚀的炼油蒸馏塔顶缓蚀剂,按照质量百分比,包括：大于等于98％的吡啶基离子液体,剩余为NaBr,吡啶基离子液体为N-烷基吡啶四氟硼酸盐或N-烷基吡啶六氟磷酸盐。本发明缓蚀剂在工业化生产和应用过程中,具有抗腐蚀效果好、用量少、成本低、水溶性好、环境友好的特点。(The invention discloses an oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide, which comprises the following components in percentage by mass: greater than or equal to 98 percent of pyridyl ionic liquid, the balance of NaBr, and the pyridyl ionic liquid is N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate. The corrosion inhibitor has the characteristics of good corrosion resistance effect, small using amount, low cost, good water solubility and environmental friendliness in the industrial production and application processes.)

1. The corrosion inhibitor for the top of the distillation tower of oil refining, which resists the corrosion of dilute hydrochloric acid and hydrogen sulfide, is characterized by comprising the following components in percentage by mass: greater than or equal to 98 percent of pyridyl ionic liquid, the balance of NaBr, and the pyridyl ionic liquid is N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate.

2. An oil refining distillation tower top corrosion inhibitor resisting corrosion of dilute hydrochloric acid and hydrogen sulfide as claimed in claim 1, wherein the pyridyl ionic liquid is prepared by the following steps:

s1, adding bromoalkane into a three-neck round-bottom flask, and fixing a constant-pressure dropping funnel containing pyridine and a condensation reflux device with a drying tube at the upper end of a transducer of an ultrasonic cleaner;

s2, carrying out ultrasonic treatment on bromoalkane, adding pyridine dropwise into the bromoalkane, carrying out ultrasonic intermittent reaction to enable clear liquid to become turbid, continuing ultrasonic treatment to generate white floccule, and filtering after continuing reaction to obtain light yellow solid;

s3, mixing the light yellow solid obtained in the step S2 with acetone and sodium tetrafluoroborate or sodium hexafluorophosphate, stirring for reaction at room temperature, and filtering to remove white precipitate NaBr in the filtrate;

s4, adding dichloromethane into the filtrate filtered in the step S3 to generate white precipitate, removing acetone and dichloromethane through filtration and rotary evaporation, and obtaining N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate through vacuum drying treatment.

3. An oil refining distillation tower top corrosion inhibitor for resisting corrosion of dilute hydrochloric acid and hydrogen sulfide as claimed in claim 2, wherein in step S1, the alkyl bromide is methyl bromide, butyl bromide or dodecyl bromide, and the molar ratio of pyridine to alkyl bromide is 1 (1.1-1.3).

4. An oil refining distillation tower top corrosion inhibitor for resisting dilute hydrochloric acid and hydrogen sulfide corrosion according to claim 2, wherein in step S2, ultrasonic treatment is performed under the protection of Ar, the speed of dripping pyridine is less than or equal to 10mL/min, the intermittent operation time of ultrasonic wave is 5-10 min, and the reaction is continued for 1.8-2.2 h after white floccule is generated and then is stopped.

5. A refinery distillation overhead corrosion inhibitor against corrosion by dilute hydrochloric acid and hydrogen sulfide as claimed in claim 2, wherein in step S3, the ratio of light yellow solid: acetone: the molar ratio of (sodium tetrafluoroborate or sodium hexafluorophosphate) is 1: (1.8-2.0): (1.05-1.15).

6. An oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide as claimed in claim 5, wherein the corrosion inhibitor is filtered after being reacted for 12-13 h under magnetic stirring at room temperature.

7. An oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide as claimed in claim 2, wherein in step S4, the addition amount of dichloromethane is 20-30 mL, the treatment time of rotary evaporation is 3-4 h, the vacuum drying temperature is 40-45 ℃, and the time is 20-25 h.

8. An oil refining distillation tower top corrosion inhibitor for resisting dilute hydrochloric acid and hydrogen sulfide corrosion according to claim 2, wherein the corrosion rate of the corrosion inhibitor in the environment of the top of a petroleum refining distillation tower containing dilute hydrochloric acid and hydrogen sulfide is 2.107-2.869 mm/a.

Technical Field

The invention belongs to the technical field of chemical industry, and particularly relates to an oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide.

Background

Atmospheric and vacuum distillation is the first work in the petroleum refining process of crude oil and is the basis of the whole petroleum refining process. According to API 571 & 2011 refinery equipment damage mechanism, the number of damage types related to the atmospheric and vacuum distillation device is more than 20, and the number of atmospheric distillation tower top systems is 8. HCl corrosion and H of the overhead system of an atmospheric and vacuum distillation unit₂S corrosion always troubles important problems of refineries at home and abroad and restricts the bottleneck of long-term operation of refining enterprises. According to physical property analysis of the top of the distillation tower, the water in the oil-water mixture at the top of the distillation tower is low in acidity, even the pH value reaches 1-1.3, and serious liquid acidic water corrosion may exist. Particularly, the content of HCl is higher at a dew point position, even the content of HCl in liquid water at the dew point position is reported to reach 1-3 wt.%, and carbon steel can be subjected to rapid dew point corrosion in the acid environment.

At present, for corrosion of a distillation tower top system, refinery process corrosion prevention is mainly adopted, and material corrosion prevention is auxiliary. The most common corrosion prevention method is 'one-removing three-injecting', namely electric desalting, water injection, corrosion inhibitor injection and neutralizer injection. The corrosion inhibitor is mainly composed of quinoline quaternary ammonium salt or pyridine quaternary ammonium salt, thiourea and derivatives thereof are compounded to improve the corrosion inhibition performance of the quinoline quaternary ammonium salt or the pyridine quaternary ammonium salt, and meanwhile, an organic solvent, a surfactant, an organic base and the like are added to meet the requirements of physicochemical performance. With the promulgation of novel environmental protection laws, organic solvents have obvious pollution to the environment. The surfactant is organic chlorine generally, belongs to toxic and harmful substances, and is not friendly to the environment. Therefore, the compound corrosion inhibitor added with the solvent, the synergist and the surfactant belongs to chemical products which are not friendly to the environment, and the future development and application of the compound corrosion inhibitor are greatly influenced.

Disclosure of Invention

The technical problem to be solved by the invention is to provide an oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide, which is suitable for overcoming the defects in the prior artAt higher temperatures and HCl with H₂The corrosion inhibition effect is good, no solvent is used, the environment is friendly, the water solubility is good, and the dosage is small.

The invention adopts the following technical scheme:

an oil refining distillation tower top corrosion inhibitor resisting corrosion of dilute hydrochloric acid and hydrogen sulfide comprises the following components in percentage by mass: greater than or equal to 98 percent of pyridyl ionic liquid, the balance of NaBr, and the pyridyl ionic liquid is N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate.

Specifically, the preparation process of the pyridyl ionic liquid is as follows:

s1, adding bromoalkane into a three-neck round-bottom flask, and fixing a constant-pressure dropping funnel containing pyridine and a condensation reflux device with a drying tube at the upper end of a transducer of an ultrasonic cleaner;

s2, carrying out ultrasonic treatment on bromoalkane, adding pyridine dropwise into the bromoalkane, carrying out ultrasonic intermittent reaction to enable clear liquid to become turbid, continuing ultrasonic treatment to generate white floccule, and filtering after continuing reaction to obtain light yellow solid;

s3, mixing the light yellow solid obtained in the step S2 with acetone and sodium tetrafluoroborate or sodium hexafluorophosphate, stirring for reaction at room temperature, and filtering to remove white precipitate NaBr in the filtrate;

s4, adding dichloromethane into the filtrate filtered in the step S3 to generate white precipitate, removing acetone and dichloromethane through filtration and rotary evaporation, and obtaining N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate through vacuum drying treatment.

Further, in step S1, the alkyl bromide is methyl bromide, butyl bromide or dodecyl bromide, and the molar ratio of pyridine to alkyl bromide is 1 (1.1-1.3).

Further, in step S2, performing ultrasonic treatment under the protection of Ar, dropping pyridine at a speed less than or equal to 10mL/min, performing ultrasonic intermittent operation for 5-10 min, and continuing to react for 1.8-2.2 h after generating white floccules.

Further, in step S3, a light yellow solid: acetone: the molar ratio of (sodium tetrafluoroborate or sodium hexafluorophosphate) is 1: (1.8-2.0): (1.05-1.15).

Further, the mixture is magnetically stirred at room temperature for reaction for 12-13 h and then filtered.

Further, in the step S4, the adding amount of the dichloromethane is 20-30 mL, the processing time of the rotary evaporation is 3-4 h, the vacuum drying temperature is 40-45 ℃, and the time is 20-25 h.

Furthermore, the corrosion rate of the corrosion inhibitor in the environment of the top of the petroleum refining distillation tower containing dilute hydrochloric acid and hydrogen sulfide is 2.107-2.869 mm/a.

Compared with the prior art, the invention has at least the following beneficial effects:

the corrosion inhibitor for the distillation tower top of oil refining, which is resistant to corrosion of dilute hydrochloric acid and hydrogen sulfide, does not contain solvents, synergists and other chemical agents, contains pyridine rings in molecules, and has strong binding force with the metal surface, so that the corrosion inhibitor can realize high-efficiency corrosion inhibition performance without adding the synergists, and has the characteristics of low corrosion rate, good corrosion inhibition effect, no solvent, environmental friendliness and small using amount.

Furthermore, the corrosion inhibitor only contains a corrosion inhibition effective component N-alkylpyridine tetrafluoroborate or N-alkylpyridine hexafluorophosphate, and is environment-friendly.

Furthermore, the preparation of the pyridyl ionic liquid corrosion inhibitor is simple and convenient, and no toxic and harmful by-products are generated.

Furthermore, the bromoalkane and the pyridine are mixed according to the mass ratio of (1.1-1.3) to 1, so that the pyridine can be fully reacted.

Furthermore, Ar is used as a protective gas, pyridine is added at a speed of less than or equal to 15mL/min, and the pyridine and the bromoalkane are ensured to uniformly react under the condition of air isolation.

Furthermore, acetone is used as a solvent, and the amount ratio of substances of the light yellow solid, (sodium tetrafluoroborate or sodium hexafluorophosphate) to acetone is 1 (1.05-1.15) to (1.8-2.2), so that the obtained ionic liquid in the light yellow solid can be fully reacted.

Further, magnetically stirring the obtained ionic liquid for 12-13 h, removing NaBr generated in the reaction, and obtaining the imidazoline-based ionic liquid with high purity.

In conclusion, the corrosion inhibitor has the characteristics of good corrosion resistance effect, small using amount, low cost, good water solubility and environmental friendliness in the industrial production and application processes.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic diagram of the reaction scheme of the present invention.

Detailed Description

The invention provides an oil refining distillation tower top corrosion inhibitor capable of resisting corrosion of dilute hydrochloric acid and hydrogen sulfide, which contains more than 98% of pyridyl ionic liquid by mass percent, no synergist or solvent is added, the content reaches more than 98%, the balance is NaBr, the pyridyl ionic liquid is N-alkylpyridines tetrafluoroborate or N-alkylpyridines hexafluorophosphate, and the corrosion rate is 2.107-2.869 mm/a. The corrosion inhibitor can be used at higher temperature and high HCl + H₂And in the environment of the top of the petroleum refining distillation tower, metal pipelines and equipment are effectively protected. The corrosion inhibitor has the characteristics of good corrosion resistance effect, small using amount, low cost, good water solubility and environmental friendliness in the industrial production and application processes.

Referring to FIG. 1, N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate is prepared by the following process:

s1, adding a certain amount of brominated alkane (R-Br, the amount of the substance is 33-39 mmol) into a three-neck round-bottom flask, placing 30mmol of pyridine in a constant-pressure dropping funnel and a condensation reflux device with a drying tube, and carrying out ultrasonic treatment for 5-10 min after the pyridine is fixed at the upper end of a transducer of an ultrasonic cleaner; the brominated alkane is methyl bromide, butyl bromide or brominated dodecyl alkane;

the brominated alkane is methyl bromide, butyl bromide or dodecyl bromide.

S2, under the condition of ultrasonic treatment under Ar protection, pyridine is dripped at a speed of less than or equal to 10mL/min, the clear liquid turns turbid after the reaction is carried out for 5-10 min under the Ar protection ultrasonic intermittent operation mode, white floccule is generated by continuing ultrasonic treatment, the reaction is stopped after 1.8-2.2 h of reaction, and light yellow solid is obtained by filtration;

s3, adding the light yellow solid, sodium tetrafluoroborate (NaBF4) or sodium hexafluorophosphate (NaPF6) and acetone into a single-neck round-bottom flask with a condensation reflux device according to the mass ratio of 1 (1.05-1.15) to (1.8-2.0), magnetically stirring at room temperature for reaction for 12-13 h, and filtering to remove white precipitate NaBr;

s4, adding 20-30 mL of dichloromethane into the filtrate, performing rotary evaporation for 3-4 h to remove acetone and dichloromethane in the filtrate, and performing vacuum drying at 40-45 ℃ for 20-25 h to obtain N-alkylpyridinium tetrafluoroborate or N-alkylpyridinium hexafluorophosphate.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The method for measuring the corrosion rate of the corrosion inhibitor in each embodiment of the invention comprises the following steps:

medium composition: HCl: 1g/L, H₂S：1g/L；

Test temperature: 85 ℃;

test time: 6 hours;

test materials: 20# steel.

Polishing 20# steel, cleaning the polished 20# steel by petroleum ether, acetone and ethanol, drying, weighing, putting the prepared solution into a reaction container with a reflux device, adding 100ppm of the prepared corrosion inhibitor, uniformly stirring, hanging the weighed 20# steel into the reaction container, heating to 85 ℃, stabilizing for 6 hours under the condition, taking out a sample, removing a corrosion product film on the surface of the sample, drying, weighing and calculating the corrosion rate.