CN108315062B - Gasoline copper sheet corrosion inhibitor and preparation method thereof - Google Patents

Abstract

The invention discloses a gasoline copper sheet corrosion inhibitor, which belongs to the technical field of gasoline corrosion inhibition and is prepared by compounding the following raw materials in parts by weight: 3-6 parts of potassium hydroxide; 10-20 parts of sulfonated cobalt phthalocyanine; 2-3 parts of cobalt acetylacetonate; 5-7 parts of sodium benzoate; 2-6 parts of sodium acetate. The inhibitor has good sensitivity, has wide application range to the product gasoline of the device, and can not be unqualified due to the change of the property of the raw oil; the reaction is sufficient, the dispersion effect is good, no sediment is generated, and no adverse effect is caused on the detection and use of the product; the sodium benzoate is an excellent preservative, and can play a very good role in preventing corrosion in a harsher environment; in the product storage process, the product can play a role in dispersion, so that the phenomenon that a large amount of precipitates appear in a storage tank due to standing, settling and precipitation of a complex reactant in the product is avoided, and the product can be stored for a long time.

Description

Gasoline copper sheet corrosion inhibitor and preparation method thereof

Technical Field

The invention relates to a gasoline additive, in particular to a gasoline copper sheet corrosion inhibitor and a preparation method thereof. Belongs to the technical field of gasoline corrosion inhibition.

Background

The qualification of the copper sheet corrosion test is one of the important standards for testing the quality of gasoline. At present, the problem that the copper sheet is not qualified in corrosion generally exists in gasoline produced by heavy oil catalytic cracking, so that oil refiners are often forced to remix or remix the gasoline to be sold as qualified finished oil, and the economic benefit of the refiners is greatly influenced. Therefore, the problem of corrosion of the gasoline copper sheet is solved, and the problem is an imminent technical problem for gasoline manufacturers. Gasoline copper sheet corrosion inhibitors are various in variety, and are mainly classified into amines and phenols at present.

The causes of corrosion of copper sheets mainly come from the following three aspects: 1. analyzing whether the operation is normal: the test tube, the measuring tool and the container used in the analysis operation process are not clean, the oil product is not discharged completely during sampling, the oil product is not kept still for a long time, the filtering is not good, the copper sheet manufacturing process is not standard, and the like, so that the copper sheet is not qualified in corrosion. The solution is to standardize the operation of the analysis process. 2. Whether corrosive impurities are contained: corrosive impurities generally refer to water, alkali, or other polar solvents entrained with the sample during refining. Such corrosion is typically caused by emulsification in the finishing section or by insufficient settling time in the settling tank. The general expression is as follows: the corrosion of the distillation outlet is unqualified, and the corrosion is reduced or improved when the finished product tank is used for sampling. The solution is to improve the reaction conditions to reduce the emulsification or to increase the settling time. 3. Whether oil refining is thorough or not: the removal of acidic compounds is an important purpose of oil product refining, and the corrosion of copper sheets is a control index of the removal degree of the acidic compounds. The acidic compounds in gasoline or liquefied gas are basically two types of acidic oxides and active sulfides. The active sulfur compounds include elemental sulfur, hydrogen sulfide, and mercaptans, thiophenols (collectively referred to as thiolated sulfur). The acidic oxides and hydrogen sulfide are highly acidic and are easily removed from the oil by alkaline washing. In contrast, mercaptan sulfur is less acidic, and the removal of mercaptans by caustic scrubbing alone consumes a large amount of caustic, generates a large amount of malodorous caustic sludge, and generally converts mercaptans to disulfides by a catalytic oxidation process. At normal temperature, the element sulfur does not react with alkali or acid and is difficult to remove from the oil product, so most of the causes of copper sheet corrosion of the oil product are caused by the element sulfur. Elemental sulfur alone, only 0.34ppm can cause significant gray-black corrosion.

The source of elemental sulfur has two aspects, namely, the elemental sulfur is carried by crude oil per se, and the situation is generally rare; secondly, hydrogen sulfide is generated in the weak oxidation environment of the mercaptan removal process, which is the main cause of elemental sulfur corrosion. The reaction equation for elemental sulfur formation is as follows:

H₂S+OH^－→HS^－+H₂O；HS^－+H₂O+O₂→S+OH^－

elemental sulfur and its sulfides cause corrosion of copper sheets: 1. corrosion by hydrogen sulfide: hydrogen sulfide is a colorless, odorous, acidic gas that has little solubility in water but greater solubility in gasoline. And when the content of hydrogen sulfide in the gasoline is larger, the corrosion characteristics of the copper sheet caused by the gasoline are as follows: the corrosion copper sheet is mainly red, and the color of the corrosion copper sheet is changed from mauve to magenta along with the increase of the concentration of the hydrogen sulfide. 2. Mercaptan corrosion: under the general experimental conditions (when the oil product contains trace mercaptan at low temperature), the mercaptan does not generate copper sheet corrosion; when the temperature is higher than 100 ℃, the corrosivity of mercaptan on the copper sheet is obviously enhanced, and the property of active sulfide can be shown. 3. Elemental sulfur corrosion: the trace element sulfur has good solubility in hydrocarbon oil and strong reactivity to nonferrous metals. The elemental sulfur has strong copper sheet corrosivity, and when the elemental sulfur content in the oil product is 0.34ppm, the copper sheet corrosion level can reach level 1 b. Meanwhile, elemental sulfur is easy to be adducted with alkyl disulfide to form polysulfide, and copper sheet corrosion is caused.

And when the finished gasoline copper sheet is unqualified in corrosion, the most effective and economic scheme for solving the problem of gasoline copper sheet corrosion is realized by adding the gasoline copper sheet corrosion inhibitor.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a gasoline copper sheet corrosion inhibitor and a preparation method thereof, wherein the gasoline copper sheet corrosion inhibitor has good complexing and dispersing effects, no precipitate, no rebound and short action time.

In order to achieve the purpose, the invention adopts the following technical scheme:

the gasoline copper sheet corrosion inhibitor is mainly prepared by compounding the following raw materials in parts by weight:

a preparation method of a gasoline copper sheet corrosion inhibitor comprises the following steps:

1) dissolving the potassium hydroxide with the process quantity in ethanol with the mass of 3 times of that of the potassium hydroxide, and uniformly stirring;

2) adding the sulfonated cobalt phthalocyanine, the cobalt acetylacetonate, the sodium benzoate and the sodium acetate in sequence according to the process quantity, and uniformly mixing to obtain the composite material.

The principle of the invention is as follows: 1. the potassium hydroxide can react with active sulfide of non-corrosive metal and element sulfur in gasoline to generate potassium sulfite, 3S +6KOH is 2K₂S+K₂SO₃+3H₂O; 2. the sulfonated cobalt phthalocyanine exists in the form of a catalyst, so that the reaction process is greatly accelerated, and an obvious catalytic effect is achieved. 3. Cobalt acetylacetonate is an organic reaction catalyst, and can remove organic sulfur which can not participate in the reaction and transfer the organic sulfur to alkali liquor; 4. sodium benzoate is an excellent preservative; 5. the sodium acetate fine complexing agent can complex metal ions generated by reaction, stabilize new ions and avoid corrosion.

The invention is suitable for inhibiting the factors that the copper sheet is not qualified in corrosion in gasoline detection, and compared with the prior art, the invention has the advantages that:

1) the sensitivity is good, the application range of the device product gasoline is wide, and the unqualified phenomenon caused by the change of the properties of the raw oil can be avoided;

2) the reaction is sufficient, the dispersion effect is good, no sediment is generated, and no adverse effect is caused on product detection and use.

3) Is suitable for industrial production, and the product meets the industrial use requirement;

4) the added sodium benzoate is an excellent preservative, and can play a very good role in preventing corrosion in a harsher environment; in the product storage process, the product can play a role in dispersion, so that the phenomenon that a large amount of precipitates appear in a storage tank due to standing, settling and precipitation of a complex reactant in the product is avoided, and the product can be stored for a long time.

Detailed Description

The present invention will be further illustrated by the following examples, which are intended to be merely illustrative and not limitative.

Example 1

Preparation of a gasoline copper sheet corrosion inhibitor:

1) dissolving 5kg of potassium hydroxide in 15kg of ethanol, and uniformly stirring;

2) adding 15kg of sulfonated cobalt phthalocyanine, 2kg of cobalt acetylacetonate, 6kg of sodium benzoate and 3kg of sodium acetate in sequence, and uniformly mixing.

Example 2

Preparation of a gasoline copper sheet corrosion inhibitor:

1) dissolving 5kg of potassium hydroxide in 15kg of ethanol, and uniformly stirring;

2) adding 12kg of sulfonated cobalt phthalocyanine, 3kg of cobalt acetylacetonate, 7kg of sodium benzoate and 2kg of sodium acetate in sequence, and uniformly mixing.

Example 3

Preparation of a gasoline copper sheet corrosion inhibitor:

1) 6kg of potassium hydroxide is dissolved in 18kg of ethanol and is stirred uniformly;

2) adding 20kg of sulfonated cobalt phthalocyanine, 2kg of cobalt acetylacetonate, 5kg of sodium benzoate and 2kg of sodium acetate in sequence, and uniformly mixing.

TABLE 1 raw material formulation (unit: kg) of gasoline copper sheet corrosion inhibitor

Composition (I)	Example 1	Example 2	Example 3
				Potassium hydroxide	5	5	6
Sulfonated cobalt phthalocyanine	15	12	20
				Cobalt acetylacetonate	2	3	2
Sodium benzoate	6	7	5
				Sodium acetate	3	2	2

The corrosion inhibition performance of the gasoline with the corrosion inhibitor and the gasoline without the corrosion inhibitor is compared, and the test results are shown as follows:

TABLE 2 copper sheet Corrosion inhibitor COMPARATIVE TABLE

It can be confirmed from table 2 that the corrosion inhibitor obtained by adding the preparation method of the invention can change the light hydrocarbon which does not reach the corrosion standard of the copper sheet into qualified light hydrocarbon, i.e. the copper sheet corrosion grade of the light hydrocarbon reaches the standard, and the addition amount of the corrosion inhibitor is smaller than that of the corrosion inhibitor in the published patent, so that the inhibition effect is better.

Although the present invention has been described with reference to the specific embodiments, it is not intended to limit the scope of the present invention, and various modifications and variations can be made by those skilled in the art without inventive changes based on the technical solution of the present invention.

Claims (2)

1. The gasoline copper sheet corrosion inhibitor is characterized by being mainly prepared by compounding the following raw materials in parts by weight:

the preparation method of the gasoline copper sheet corrosion inhibitor comprises the following steps:

1) dissolving the potassium hydroxide with the process quantity in ethanol with the mass of three times that of the potassium hydroxide, and uniformly stirring;

2) adding the sulfonated cobalt phthalocyanine, the cobalt acetylacetonate, the sodium benzoate and the sodium acetate in sequence according to the process quantity, and uniformly mixing to obtain the composite material.

2. The gasoline copper sheet corrosion inhibitor according to claim 1, which is mainly prepared by compounding the following raw materials in parts by weight: