Preparation process of neutral amino acid-based scale and corrosion inhibitor

Abstract

The invention relates to the technical field of scale and corrosion inhibitors, and discloses a preparation process of a neutral amino acid scale and corrosion inhibitor, 3, 5-dihydroxy benzaldehyde, taurine, epichlorohydrin and N, N, N ', N'-tetramethylethylenediamine are subjected to a reaction to obtain the scale and corrosion inhibitor, sulfonate and hydroxyl contained in the scale and corrosion inhibitor, barium ions and strontium ions form a stable chelate, and the scale and corrosion inhibitor can be used for preparing the neutral amino acid scale and corrosion inhibitor. Barium ions and strontium ions can be prevented from being combined with anions such as sulfate radicals to form insoluble precipitates such as barium sulfate and strontium sulfate, and the scale inhibitor has good scale inhibition performance. The scale and corrosion inhibitor contains a plurality of active coordination centers such as quaternary ammonium salt cations, sulfonate and hydroxyl, and is coordinated and interacted with the surface of a steel sheet, so that a layer of tight and firm protective film is formed on the surface, corrosive media such as hydrochloric acid are prevented from being in contact with the steel sheet, and the scale and corrosion inhibitor has good corrosion prevention and inhibition performance at high temperature; good practical application is realized in the aspect of oilfield water injection oil extraction.

Description

Technical Field

[0001] The invention relates to the technical field of scale inhibitors and corrosion inhibitors, and in particular to a preparation process of a neutral amino acid-based scale inhibitor and corrosion inhibitor. Background Art

[0002] In some areas of the oil field, due to the high mineralization of produced water, when the produced fluid is incompatible with the injected water, it will cause serious scaling in the oil and water well pipe pump, near-well reservoir, etc., forming a large amount of inorganic scale such as barium sulfate, strontium sulfate, and calcium carbonate, which seriously affects the normal production of oil and water wells. In addition, there are more corrosive gases such as carbon dioxide and hydrogen chloride dissolved in the produced water, which leads to the continuous deterioration of the injection water quality, causing serious corrosion to the pipeline equipment in the injection system, and posing a major safety hazard. The development of new scale and corrosion inhibitors is of great significance. Chinese patent CN111704250B discloses a neutral corrosion and scale inhibitor for oil fields and a preparation method thereof. Chloroacetic acid, sodium hydroxide solution, ethylenediamine, phosphorous acid, aminotriyl phosphoric acid, dipolycarboxyethyl hypophosphorous acid, etc. are compounded to obtain a neutral corrosion and scale inhibitor having both good corrosion and scale inhibition properties. However, the corrosion and scale inhibitor does not show a good scale inhibition effect on strontium and barium scale, and the corrosion and scale inhibitor contains a large amount of phosphorus-containing substances, which enter into the natural water environment and are likely to cause environmental problems such as eutrophication of water bodies and red tides. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a preparation process of a neutral amino acid-based scale inhibitor and corrosion inhibitor, which solves the problem that the existing scale inhibitor and corrosion inhibitor has poor scale inhibition performance on barium and strontium, and at the same time has good high temperature resistance and corrosion resistance.

[0004] Technical solution: Preparation process of a neutral amino acid-based scale and corrosion inhibitor: (1) Methanol, 3,5-dihydroxybenzaldehyde and taurine are added to a reaction vessel, and a methanol solution containing potassium hydroxide is added dropwise. After the reaction, rotary evaporation is performed, and the product is recrystallized in an ethanol aqueous solution to obtain a 3,5-dihydroxybenzaldehyde potassium taurine Schiff base.

[0005] (2) Toluene, epichlorohydrin, 3,5-dihydroxybenzaldehyde potassium taurate Schiff base, and benzyltriethylammonium chloride (TEBAC) are added to a reaction vessel. After the reaction, rotary evaporation is performed, and the product is washed with petroleum ether. The product is recrystallized in an ethanol aqueous solution to obtain 3,5-di(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base. The preparation reaction formula is: .

[0006] (3) Add solvent, 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurine Schiff base and N,N,N',N'-tetramethylethylenediamine in a molar ratio of 1:(0.9-1.1) to the reaction container, cool the solution after the reaction, pour it into ethanol, filter it, wash it with ethanol, and dry it to obtain a neutral amino acid-based scale inhibitor. The preparation reaction formula is: .

[0007] Preferably, the reaction in (1) is stirred at 30-50° C. for 1-2 h.

[0008] Preferably, the molar ratio of 3,5-dihydroxybenzaldehyde, taurine and potassium hydroxide in (1) is 1:(1-1.2):(1-1.2).

[0009] Preferably, the reaction temperature in (2) is 90-100°C and the reaction time is 8-12h.

[0010] Preferably, the molar ratio of epichlorohydrin, 3,5-dihydroxybenzaldehyde potassium taurate Schiff base, and benzyltriethylammonium chloride in (2) is (10-14):1:(0.11-0.15).

[0011] Preferably, the solvent in (3) is N,N-dimethylformamide or N,N-dimethylacetamide.

[0012] Preferably, the reaction in (3) is stirred at 90-120° C. for 24-48 h.

[0013] The invention has the beneficial technical effects as follows: the scale inhibitor and corrosion inhibitor prepared by the invention contains sulfonate and quaternary ammonium salt zwitterionic structures, presents electrical neutrality, has little corrosion and damage to the steel pipeline substrate in the oil field water injection system, contains a large number of hydroxyl, sulfonate, and quaternary ammonium salt hydrophilic groups, has good solubility in water, and the sulfonate and hydroxyl contained in the invention have strong chelating properties, and form stable chelates with barium ions and strontium ions, which can prevent barium ions and strontium ions from combining with anions such as sulfate to form insoluble precipitates such as barium sulfate and strontium sulfate, thereby achieving good scale inhibition and anti-scaling performance.

[0014] The scale inhibitor of the present invention is a polymer containing a benzene ring, has good heat resistance, and contains multiple active coordination centers of quaternary ammonium salt cations, sulfonates and hydroxyls, which have strong coordination interactions with the surface of the steel sheet, forming a tight and firm protective film on the surface of the steel sheet, which can effectively block the contact of corrosive media such as hydrochloric acid with the steel sheet, and has good anti-corrosion and corrosion inhibition performance at high temperatures. The scale inhibitor of the present invention does not contain phosphorus, is green, environmentally friendly and pollution-free, and has good practical applications in water injection and oil production in oil fields. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0016] Example 1 (1) Add 60 mL of methanol, 20 mmol of 3,5-dihydroxybenzaldehyde, and 20 mmol of taurine to a reaction vessel equipped with a condenser reflux tube, add 60 mL of a methanol solution containing 20 mmol of potassium hydroxide dropwise, stir and react at 50°C for 1 h, remove the methanol by rotary evaporation, and recrystallize the product in a 50% by volume ethanol aqueous solution to obtain 3,5-dihydroxybenzaldehyde potassium taurine Schiff base.

[0017] (2) Add 30 mL of toluene, 140 mmol of epichlorohydrin, 10 mmol of 3,5-dihydroxybenzaldehyde potassium taurate Schiff base, and 0.1 mmol of benzyltriethylammonium chloride to a reaction vessel equipped with a condenser reflux tube, and stir at 90°C for 12 h. Remove toluene and epichlorohydrin by rotary evaporation, wash with petroleum ether, and recrystallize the product in 70% by volume ethanol aqueous solution to obtain 3,5-di(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base.

[0018] (3) Add 200 mL of N,N-dimethylformamide, 20 mmol of 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base, and 20 mmol of N,N,N',N'-tetramethylethylenediamine into a reaction container, stir and react at 110°C for 30 h, and after cooling, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain a neutral amino acid-based scale inhibitor.

[0019] Example 2 (1) Add 80 mL of methanol, 20 mmol of 3,5-dihydroxybenzaldehyde, and 24 mmol of taurine into a reaction vessel, add dropwise 70 mL of a methanol solution containing 24 mmol of potassium hydroxide, stir at 30°C for 2 h, remove the methanol by rotary evaporation, and recrystallize the product in a 50% by volume ethanol aqueous solution to obtain 3,5-dihydroxybenzaldehyde potassium taurine Schiff base.

[0020] (2) Add 20 mL of toluene, 100 mmol of epichlorohydrin, 10 mmol of 3,5-dihydroxybenzaldehyde potassium taurate Schiff base, and 0.15 mmol of benzyltriethylammonium chloride to a reaction vessel equipped with a condenser reflux tube, stir at 100° C. for 8 h, remove toluene and epichlorohydrin by rotary evaporation, wash with petroleum ether, and recrystallize the product in 70% by volume ethanol aqueous solution to obtain 3,5-di(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base.

[0021] (3) Add 200 mL of N,N-dimethylacetamide, 20 mmol of 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base, and 22 mmol of N,N,N',N'-tetramethylethylenediamine into a reaction container, stir and react at 90°C for 48 h, and after cooling, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain a neutral amino acid-based scale inhibitor.

[0022] Example 3 (1) Add 200 mL of N,N-dimethylformamide, 20 mmol of 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base (prepared in Example 1), and 18 mmol of N,N,N',N'-tetramethylethylenediamine into a reaction container, stir and react at 120° C. for 24 h, and after cooling, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain a neutral amino acid-based scale inhibitor.

[0023] Comparative Example 1: 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base is used as a scale inhibitor (prepared in Example 1).

[0024] Comparative Example 2 (1) Add 200 mL of N,N-dimethylformamide and 20 mmol of p-dibenzyl chloride (structural formula: ), 20mmol N,N,N',N'-tetramethylethylenediamine, stir and react at 110°C for 30h, pour the solution into ethanol after cooling, filter, wash with ethanol, and dry to obtain a scale inhibitor and corrosion inhibitor.

[0025] Comparative Example 3 (1) Add 30 mL of toluene, 140 mmol of epichlorohydrin, 10 mmol of hydroquinone, and 0.1 mmol of benzyltriethylammonium chloride to a reaction vessel equipped with a condenser reflux tube, stir at 90°C for 12 h, remove toluene and epichlorohydrin by rotary evaporation, and recrystallize the product in ethanol to obtain 1,4-bis(3-chloro-2-hydroxypropoxy)benzene, with the structural formula: .

[0026] (2) Add 200 mL of N,N-dimethylformamide, 20 mmol of 1,4-bis(3-chloro-2-hydroxypropoxy)benzene, and 20 mmol of N,N,N',N'-tetramethylethylenediamine into a reaction container, stir and react at 110°C for 30 h, and after cooling, pour the solution into ethanol. After filtering, wash with ethanol, and dry to obtain a scale inhibitor and corrosion inhibitor.

[0027] According to the method specified in SY / T 5673-2020 standard, the scale inhibition rate of scale inhibitors on barium sulfate and strontium sulfate was tested. The addition amount of scale inhibitors was 10-25 mg / L. The test results are shown in Table 1-2.

[0028] Table 1 Anti-scaling rate test of barium sulfate

[0029] Table 2 Strontium sulfate anti-scaling rate test

[0030] After testing, the scale inhibition and corrosion inhibitors of Examples 1-3 have the highest scale inhibition rates for barium sulfate and strontium sulfate of 98.5% and 96.0%, respectively. This is mainly because the scale inhibition and corrosion inhibitors contain sulfonate, hydroxyl and quaternary ammonium salt hydrophilic groups, and have good solubility in water. At the same time, the sulfonate and hydroxyl contained in them have strong chelating properties, forming stable chelates with barium ions and strontium ions, which can prevent barium ions and strontium ions from combining with anions such as sulfate to form insoluble precipitates such as barium sulfate and strontium sulfate, thereby achieving good scale inhibition and corrosion prevention performance.

[0031] Comparative Example 1 uses 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde taurine potassium Schiff base as a scale inhibitor and corrosion inhibitor. It also contains sulfonates and hydroxyls, which have strong chelating properties and form stable chelates with barium ions and strontium ions, playing a good scale inhibition and anti-scaling performance. However, its barium sulfate and strontium sulfate scale inhibition rates are lower than those of each Example 1, mainly because 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde taurine potassium does not contain quaternary ammonium salt cationic hydrophilic groups and has poor water solubility, which affects its scale inhibition performance. Comparative Example 2 uses p-dibenzyl chloride and N,N,N',N'-tetramethylethylenediamine as raw materials. The prepared scale inhibitor does not contain sulfonates and hydroxyls, cannot play a chelating role, and is difficult to form stable chelates with barium ions and strontium ions. The scale inhibition rate is very low and the scale inhibition and anti-scaling performance is very poor. In Comparative Example 3, 1,4-bis(3-chloro-2-hydroxypropoxy)benzene and N,N,N',N'-tetramethylethylenediamine are used as reactants. The obtained scale inhibitor does not contain sulfonate groups, has poor chelating properties, low scale prevention rate, and poor scale inhibition performance.

[0032] According to the method specified in SYT / 5273-2014 standard, the corrosion inhibition performance of the scale and corrosion inhibitor was tested. The test sample was A3 steel sheet (specification 50mm×13mm×1.5mm), the corrosion solution was a hydrochloric acid solution with a mass fraction of 20%, the amount of scale and corrosion inhibitor in the corrosion solution was 5-20mg / L, and the corrosion solution was heated to 90℃, condensed and refluxed during the test, and the test time was 24h. The corrosion inhibition performance test results are shown in Table 3.

[0033] Table 3: Corrosion inhibition performance test

[0034] After testing, compared with comparative examples 1-3, the high-temperature corrosion inhibition rate of the scale inhibitor and corrosion inhibitor of Examples 1-3 for A3 steel sheets reached as high as 93.7%. This is mainly because the scale inhibitor and corrosion inhibitor is a polymer containing benzene rings, which has good heat resistance. It also contains multiple active coordinated neutrals such as quaternary ammonium salt cations, sulfonates and hydroxyls, which have strong coordination interactions with the surface of the steel sheet, forming a tight and firm protective film on the surface of the steel sheet, which can effectively block corrosive media such as hydrochloric acid from contacting the steel sheet, and has good anti-corrosion and corrosion inhibition properties at high temperatures.

[0035] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A preparation process of a neutral amino acid-based scale and corrosion inhibitor, characterized in that: The preparation process is as follows: a solvent, a Schiff base of 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde taurine potassium and N,N,N',N'-tetramethylethylenediamine in a molar ratio of 1:(0.9-1.1) are added into a reaction container, the solution is cooled after the reaction and poured into ethanol, filtered, washed with ethanol, and dried to obtain a neutral amino acid-based scale inhibitor; The structural formula of the 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurine Schiff base is as follows: 。 2. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 1, characterized in that: The solvent is N,N-dimethylformamide or N,N-dimethylacetamide.

3. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 1, characterized in that: The reaction was stirred at 90-120 °C for 24-48 h.

4. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 1, characterized in that: The preparation process of the 3,5-bis(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurine Schiff base is as follows: (1) adding methanol, 3,5-dihydroxybenzaldehyde and taurine into a reaction container, and dropping a methanol solution containing potassium hydroxide, performing rotary evaporation after the reaction, and recrystallizing the product to obtain a Schiff base of 3,5-dihydroxybenzaldehyde potassium taurine; (2) Toluene, epichlorohydrin, 3,5-dihydroxybenzaldehyde potassium taurate Schiff base, and benzyltriethylammonium chloride are added to a reaction container. After the reaction, the product is rotary evaporated, washed, and recrystallized to obtain 3,5-di(3-chloro-2-hydroxypropoxy)benzaldehyde potassium taurate Schiff base.

5. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 4, characterized in that: The reaction in (1) is stirred at 30-50°C for 1-2h.

6. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 4, characterized in that: The molar ratio of 3,5-dihydroxybenzaldehyde, taurine and potassium hydroxide in (1) is 1:(1-1.2):(1-1.2).

7. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 4, characterized in that: The reaction temperature in (2) is 90-100°C and the reaction time is 8-12h.

8. The preparation process of the neutral amino acid-based scale and corrosion inhibitor according to claim 4, characterized in that: The molar ratio of epichlorohydrin, 3,5-dihydroxybenzaldehyde potassium taurate Schiff base and benzyltriethylammonium chloride in (2) is (10-14):1:(0.11-0.15).

Images