CN113584490A

CN113584490A - Hydrogenation corrosion inhibitor

Info

Publication number: CN113584490A
Application number: CN202110883080.XA
Authority: CN
Inventors: 徐文忠
Original assignee: Shanghai Guitong New Material Science And Technology Co ltd
Current assignee: Shanghai Guitong New Material Science And Technology Co ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2021-11-02
Anticipated expiration: 2041-08-02
Also published as: CN113584490B

Abstract

The invention discloses a hydrogenation corrosion inhibitor, which comprises a corrosion inhibitor I and is prepared by the following method: mixing triethylene tetramine and caprylic acid according to a molar ratio of 1:1, adding a solvent, heating to 140 ℃, performing amidation dehydration reaction, and keeping for 4 hours; step two, keeping the temperature at 140 ℃, adding excessive glacial acetic acid, performing acetamization dehydration reaction, and keeping for 2 hours; thirdly, heating to 240 ℃ again, blowing inert gas, performing cyclodehydration reaction, and keeping for 4 hours; and step four, exhausting inert gas, and evaporating the solvent under reduced pressure to obtain the catalyst. The invention also discloses an application method of the hydrogenation corrosion inhibitor. The invention can rapidly disperse and neutralize the pH value of condensed water at the tower top, and a compact protective film is formed on the surface of equipment to block corrosive media, thereby achieving the purpose of comprehensive corrosion prevention.

Description

Hydrogenation corrosion inhibitor

Technical Field

The invention relates to corrosion inhibitors. More particularly, the present invention relates to a power management method for low frequency RFID.

Background

The hydrogenation device is usually carried out in a high-temperature, high-pressure and hydrogen environment, and generates a large amount of H after the desulfurization of hydrogenation reaction₂And S. Under the condition of lower temperature and water existence, a large amount of H₂S causes severe corrosion to equipment. H₂The corrosion of S to generate FeS is mainly concentrated on a fractionating tower, a stripping tower, an air cooler, a heat exchanger, a dehydration tank, corresponding pipelines, an interface control measuring point and an adjusting valve of the following process flow. Compared with other anticorrosion means, the corrosion inhibitor has the advantages of convenience in use, high effect, low equipment investment and the like, is widely applied to oil refining production enterprises for a long time, and has the defects of large difference of anticorrosion effects of different brands and poor universality.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.

The invention also aims to provide a hydrogenation corrosion inhibitor which can be rapidly dispersed, neutralize the pH of condensed water at the top of a tower, form a compact protective film on the surface of equipment, block corrosive media and achieve the aim of overall corrosion prevention.

To achieve these objects and other advantages in accordance with the present invention, there is provided a hydrogenation corrosion inhibitor, comprising a first corrosion inhibitor, prepared by the following method:

mixing triethylene tetramine and caprylic acid according to a molar ratio of 1:1, adding a solvent, heating to 140 ℃, performing amidation dehydration reaction, and keeping for 4 hours;

step two, keeping the temperature at 140 ℃, adding excessive glacial acetic acid, performing acetamization dehydration reaction, and keeping for 2 hours;

thirdly, heating to 240 ℃ again, blowing inert gas, performing cyclodehydration reaction, and keeping for 4 hours;

and step four, exhausting inert gas, and evaporating the solvent under reduced pressure to obtain the catalyst.

Preferably, the solvent is xylene.

Preferably, the corrosion inhibitor II is also included, and is prepared by the following method:

mixing ethanolamine and linoleic acid at a molar ratio of 1:1, adding a solvent, heating to 80 ℃, keeping for 4 hours, and distilling off the solvent under reduced pressure to obtain the composition.

Preferably, the solvent is xylene.

Preferably, the corrosion inhibitor II is also added with ionic liquid, the ionic liquid is 1-ethyl-3-methylimidazole ethyl sulfate, and the adding weight of the ionic liquid is 1%.

The application method of the hydrogenation corrosion inhibitor is characterized by comprising the following steps:

step 1, mixing the raw materials of the corrosion inhibitor I and the corrosion inhibitor II, and adding water to prepare a diluent;

and 2, pressurizing the diluent by a pump, injecting the diluent into a top volatilization line, adding the diluent in one day, and dehydrating the diluent in a reflux tank after passing through an air cooler and a water cooler.

The invention at least comprises the following beneficial effects:

firstly, the hydrogenation corrosion inhibitor prepared by the method has dual functions of neutralizing and forming films, has good film forming property and can be injected into a moldCan be rapidly dispersed in water phase to form firm and compact adsorption film on metal surface for effectively neutralizing H₂S, raising the pH value of the condensed water, reducing the deposition amount and avoiding corrosion, wherein the melting point of the generated ammonium salt is low;

secondly, the hydrogenation corrosion inhibitor prepared by compounding is injected into a top volatilization line, and workshop application shows that the corrosion rate of pipeline equipment is effectively slowed down, and no adverse effect is caused on system operation and product quality.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Detailed Description

The present invention is further described in detail below with reference to examples to enable those skilled in the art to practice the invention with reference to the description.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.

< example 1>

The first hydrogenation corrosion inhibitor is prepared by the following method:

step one, mixing triethylene tetramine and caprylic acid according to a molar ratio of 1:1, adding xylene, heating to 140 ℃, performing amidation dehydration reaction, and keeping for 4 hours;

and step four, exhausting inert gas, and evaporating xylene under reduced pressure to obtain the catalyst.

< example 2>

The second hydrogenation corrosion inhibitor is prepared by the following method:

mixing ethanolamine and linoleic acid at a molar ratio of 1:1, adding xylene, heating to 80 ℃, keeping for 4 hours, and distilling off xylene under reduced pressure to obtain the product.

< example 3>

mixing ethanolamine and linoleic acid at a molar ratio of 1:1, adding xylene, heating to 80 ℃, keeping for 4h, distilling off xylene under reduced pressure, adding ionic liquid, wherein the ionic liquid is 1-ethyl-3-methylimidazol ethyl sulfate, and the ionic liquid is added by 1% by weight.

< example 4>

The hydrogenation corrosion inhibitor comprises a first corrosion inhibitor and a second corrosion inhibitor which are equal in weight:

hydrogenation corrosion inhibitor one was prepared from example 1;

a second hydrogenation corrosion inhibitor was prepared from example 3;

the first corrosion inhibitor and the second corrosion inhibitor are mixed and added with water to prepare the diluent.

< comparative example 1>

hydrogenation corrosion inhibitor one was prepared from example 1;

a second hydrogenation corrosion inhibitor was prepared from example 2;

< test of Corrosion inhibition Effect >

SY/T5273-2014 is taken as a test standard, a test material is a Q235 steel sheet with the specification of 50mm multiplied by 13mm multiplied by 1.5mm, petroleum ether at the temperature of 60-90 ℃ is used for degreasing, degreased cotton is used for wiping off surface grease, then the degreased cotton is immersed in absolute ethyl alcohol for soaking for 5-10min for further degreasing and dehydration, the degreased cotton is taken out and wiped by filter paper, the degreased cotton is wrapped by the filter paper after being air-dried, the wrapped cotton is placed in a dryer for 1h, examples 1-4 are added into an etching medium, a test piece is hung in the etching medium by a nylon rope, and the corrosion degree of the test piece and the corrosion inhibition degree of a corrosion inhibitor are measured by a method for measuring the quality change of the test piece after a set time. Variables examined were corrosion time and system temperature. The corrosive medium simulates the corrosive medium of oilfield produced water, as shown in table 1.

TABLE 1

CaCl₂	MgCl₂·6H₂O	KCl	NaCl	NaHCO₃	Na₂SO₄
						3g/L	2g/L	1g/L	23g/L	0.4g/L	0.2g/L

Corrosion inhibition rate calculation formula eta ═ Δ m₀-△m₁)/△m₀X 100%, wherein eta is corrosion inhibition rate,%; delta m₀The mass loss of a blank test piece is given as g; delta m₁The mass loss in g is measured for the added corrosion inhibitor.

As shown in Table 2, 20 mg. L was added to the etching medium at 20 ℃^-1The products of examples 1 to 4, examples 1 to 4 showed a rapid increase in corrosion inhibition rate in a period of 0 to 12 hours,the corrosion inhibitor basically tends to be gentle in 20h, can be adsorbed by molecules and can be converted and polymerized on the surface of the steel sheet to form a film, so that dynamic balance is achieved, and corrosion is inhibited.

TABLE 2

As shown in Table 3, 20 mg. L was added to the etching medium^-1After the corrosion inhibitors of examples 1-4, commercially available naphthenic imidazoline corrosion inhibitors and commercially available pyridine quaternary ammonium salt corrosion inhibitors are soaked for 24 hours, the corrosion inhibition rate of examples 1-24 changes more smoothly along with the rise of temperature, the molecular motion rate is accelerated along with the rise of temperature, and the products prepared in examples 1-4 are adsorbed on the surface of a steel sheet to be converted and polymerized to form a film.

TABLE 3

< mutual solubility Effect test >

The hydrogenation corrosion inhibitor compounded in the example 4 and the comparative example 1 is placed in a 250mL beaker, stirred uniformly, stored in a sealed wide-mouth bottle, and placed at room temperature for 3 months, and the stability of the solution is observed, as shown in Table 4, the hydrogenation corrosion inhibitor compounded in the example 4 has good intersolubility, is uniform and transparent, and the hydrogenation corrosion inhibitor compounded in the comparative example 1 has longer stability and certain layering, and the reason may be that the water-soluble ionic liquid 1-ethyl-3-methylimidazol ethyl sulfate salt is introduced to increase the dispersibility in the water phase.

TABLE 4

	1d	15d	30d
				Example 4	The solution is homogeneous and transparent	The solution is homogeneous and transparent	The solution is homogeneous and transparent
Comparative example 1	The solution is homogeneous and transparent	The solution is homogeneous and opaque	The solution was stratified with a small amount of precipitate

< Corrosion inhibition test in hydrogenation shop >

The hydrogenation corrosion inhibitor (diluted into 2.5% by mass of diluent) prepared in example 4 or the existing commercially available corrosion inhibitor is respectively adopted for different reflux tanks from No. 3/1 of 2021, the addition is completed within 1 day, and the wastewater in the reflux tanks is sampled and analyzed for Fe²⁺1 week 1 time, as shown in Table 5, Fe was detected by applying the reflux drum of example 4²⁺The concentration of the corrosion inhibitor is controlled below 3mg/L, the corrosion prevention effect is good, and the process index requirements are met.

TABLE 5

	Commercially available D-508	Example 4
			3 month and 15 days	4.22	3.6
3 month and 22 days	4.78	3.1
			3 month and 29 days	4.95	2.0
4 month and 5 days	5.08	1.5
			4 month and 12 days	4.97	2.1

The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the examples shown and described without departing from the generic concept as defined by the claims and their equivalents.

Claims

1. The hydrogenation corrosion inhibitor is characterized by comprising a first corrosion inhibitor, and is prepared by the following method:

2. The hydrogenation corrosion inhibitor of claim 1 wherein the solvent is xylene.

3. The hydrogenation corrosion inhibitor of claim 1, further comprising a second corrosion inhibitor prepared by the following method:

4. The hydrogenation corrosion inhibitor of claim 3 wherein the solvent is xylene.

5. The hydrogenation corrosion inhibitor of claim 3, wherein an ionic liquid is added into the second corrosion inhibitor, the ionic liquid is 1-ethyl-3-methylimidazole ethyl sulfate, and the added weight of the ionic liquid is 1%.

6. The method of using a hydrogenation corrosion inhibitor according to claim 5, comprising: