Application of rosemary extract in corrosion inhibition of steel in hydrochloric acid

Abstract

The invention provides application of a rosemary extract in corrosion inhibition of steel in hydrochloric acid, and belongs to the technical field of corrosion inhibitors. The preparation method of the rosemary extract comprises the following steps: crushing rosemary, soaking the crushed rosemary in an ethanol solution, and then carrying out ultrasonic oscillation; performing microwave extraction on the mixture subjected to ultrasonic oscillation to obtain a rosemary extracting solution; the parameters of the microwave extraction are set as follows: the microwave power is 300-500W, the microwave extraction temperature is 30-60 DEG C, and the microwave extraction time is 4-8 minutes. The prepared rosemary extracting solution has a good corrosion inhibition effect on steel in hydrochloric acid, every 40 mL of the rosemary extracting solution has the best corrosion inhibition effect on steel in 100 mL of 1 mol / L hydrochloric acid, and the corrosion inhibition rate can reach 90% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion inhibitors, and particularly relates to the application of rosemary extract in the corrosion inhibition of steel in hydrochloric acid. Background Art

[0002] Steel is a metallic material widely used in fields such as construction, manufacturing, and transportation. During production and use, steel will react with oxygen, water molecules, etc. in the environment, resulting in corrosion, which not only causes huge economic losses but also pollutes the environment. Pickling is considered an efficient method for removing rust and scale layers. HCl is widely used in pickling operations. At the same time, hydrochloric acid is also an industrial acid widely used in the chemical practice of oil well acidification. In actual operations, corrosion inhibitors are usually added to slow down or prevent the corrosion of the steel material substrate by the HCl solution. Organic corrosion inhibitors effectively adsorb on the steel surface through polar atomic functional groups such as oxygen, nitrogen, phosphorus, and sulfur in the molecular structure to form a corrosion inhibition film layer, thereby showing excellent corrosion inhibition effects. As corrosion inhibitors, plant extracts have significant advantages such as wide sources, simple preparation methods, high yields, low costs, environmental friendliness, and non-toxicity, and have good prospects in industrial applications, and have become a hot topic in the current research field of corrosion inhibitors. As a green and environmentally friendly metal anti-corrosion method, plant corrosion inhibitors have broad application prospects. Summary of the Invention

[0003] Based on the above content, the purpose of the present invention is to provide the application of rosemary extract in the corrosion inhibition of steel in hydrochloric acid.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] An application of rosemary extract in the corrosion inhibition of steel in hydrochloric acid, wherein 10 - 50 mL of rosemary extract is added to every 100 mL of hydrochloric acid solution; the concentration of the hydrochloric acid solution is 1 - 5 mol / L;

[0006] The preparation method of the rosemary extract includes the following steps:

[0007] Step 1. After crushing rosemary, soak it in an ethanol solution, and then perform ultrasonic oscillation;

[0008] Step 2. Perform microwave extraction on the mixture after ultrasonic oscillation to obtain rosemary extract;

[0009] The parameter settings for the microwave extraction are: microwave power 300 - 500 W, microwave extraction temperature 30 - 60 °C, and microwave extraction time 4 - 8 min.

[0010] In some embodiments of the present invention, the concentration of hydrochloric acid is 1 mol / L, and 40 mL of rosemary extract is added to every 100 mL of 1 mol / L hydrochloric acid solution.

[0011] In some embodiments of the present invention, the pulverization is to pulverize to 200 - 300 mesh.

[0012] In some embodiments of the present invention, the concentration of the ethanol solution is 40% - 60% v / v; after pulverizing rosemary, it is soaked in the ethanol solution, and the solid - liquid ratio is 1 g: 20 - 40 mL.

[0013] In the present invention, the concentration of the ethanol solution directly affects the extraction rate of rosemary extract. When the concentration of the ethanol solution is too high or too low, the extraction rate will decrease. Therefore, the concentration of the ethanol solution in the present invention is preferably within the above - mentioned parameter range.

[0014] In some embodiments of the present invention, the soaking time is 120 - 240 min.

[0015] In some embodiments of the present invention, the ultrasonic oscillation time is 20 - 40 min.

[0016] The present invention discloses the following technical effects:

[0017] The rosemary extract prepared by the present invention has good corrosion inhibition effect on steel in hydrochloric acid. Among them, every 40 mL of rosemary extract has the best corrosion inhibition effect on steel in 100 mL of 1 mol / L hydrochloric acid, and the corrosion inhibition rate can reach more than 90%.

[0018] The preparation method of the rosemary extract provided by the present invention is simple and has a high extraction rate. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is the surface morphology diagram of the steel with 80 mL of rosemary extract added to 200 mL of 1 mol / L hydrochloric acid solution in Example 1;

[0021] Figure 2 It is the surface morphology diagram of the steel without rosemary extract added to 1 mol / L hydrochloric acid solution in Example 1;

[0022] Figure 3AC impedance diagrams of adding different volumes of rosemary extract into 1 mol / L hydrochloric acid solution in Example 1;

[0023] Figure 4 Bode magnitude diagrams of adding different volumes of rosemary extract into 1 mol / L hydrochloric acid solution in Example 1. Detailed implementation manners

[0024] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be regarded as a limitation to the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0025] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0027] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the specification of the present invention, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are only exemplary.

[0028] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0029] The technical solutions described in the present invention are all conventional solutions in the art unless otherwise specified. The reagents or raw materials used are all purchased from commercial channels or have been publicly available unless otherwise specified.

[0030] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with examples, but the content of the present invention is not limited to the following examples only.

[0031] Example 1

[0032] After comminuting rosemary to 200 mesh, 2 g was weighed and placed in a 500 mL beaker, and 50 mL of 50% v / v ethanol solution was added for soaking for 200 min, and then ultrasonic oscillation was carried out for 30 min with an oscillation frequency of 300 Hz. Then, the BILON-ZCW-1000W microwave oven was turned on, and the microwave extraction time was set to 4 min, the microwave extraction temperature was 40 °C, and the microwave power was 300 w. Under these conditions, the active ingredients in rosemary were extracted to obtain a rosemary extract. After the extraction was completed, the rosemary extract was collected by centrifugation.

[0033] The extraction rate was calculated by the standard curve method, and the regression equation was y = 10 -6 X - 0.005, and the extraction rate reached 51.2% after calculation.

[0034] The corrosion inhibition effect of the rosemary extract on steel in hydrochloric acid was detected by electrochemical analysis and surface analysis methods.

[0035] (1) Electrochemical analysis method

[0036] The corrosion inhibition effect of the rosemary extract on steel was investigated at a certain hydrochloric acid concentration. A standard three-electrode system was used, with the reference electrode being a saturated calomel electrode, the working electrode being a steel electrode, and the auxiliary electrode being a platinum electrode. Before the experiment, the calomel electrode was soaked in saturated KCl solution, the electrolytic solution was 1 mol / L HCl, and then 10 mL, 20 mL, 30 mL, 40 mL, and 50 mL of the rosemary extract were added to each 100 mL of the solution respectively. The parameters set for the electrochemical related corrosion potential were as follows: the starting voltage was -1 v, the ending voltage was 0 v, the static time was 2 s, and the scanning rate was 0.01 v / s. The electrochemical data was retained to make an impedance diagram ( Figure 3 ), and a Bode diagram ( Figure 4 ). Among them, the electrochemical polarization curve method mainly studies the changes of relevant electrochemical parameters on the polarization curve before and after adding the corrosion inhibitor. The results showed that when 40 mL of the rosemary extract was added, the corrosion inhibition rate was the highest, and the corrosion inhibition rate was 93.1%.

[0037] (2) The surface morphology analysis of steel was carried out by SEM analysis method

[0038] The size of the steel sheet for SEM test is 0.5×0.5×0.5 cm. Before measurement, the surface of the steel sheet is polished to be smooth on a grinder, cleaned with absolute ethanol, wiped with filter paper, and then dried in an oven. After that, the dried steel sheets are respectively placed into 1 mol / L HCl solution and 80 mL rosemary extract + 200 mL 1 mol / L HCl solution, and soaked at room temperature for 6 h. After taking out the steel sheets, they are ultrasonically cleaned with ultrapure water and absolute ethanol and dried under cold air. Through a scanning electron microscope, the morphology before and after corrosion is observed under vacuum conditions( Figure 1 , Figure 2 ). The results show that the steel surface with rosemary extract added has less corrosion and higher smoothness.

[0039] Example 2

[0040] After crushing rosemary to 300 meshes, 5 g is weighed and placed into a 500 mL beaker, 120 mL of 50% v / v ethanol solution is added for soaking for 200 min, and then ultrasonic oscillation is carried out for 33 min with an ultrasonic frequency of 300 Hz. Then, the BILON-ZCW-1000W microwave oven is turned on, and the microwave extraction time is set to 5 min, the microwave extraction temperature is 45 °C, and the microwave power is 400 w to extract the active ingredients in rosemary to obtain rosemary extract. After the extraction is completed, the rosemary extract is collected by centrifugation.

[0041] The extraction rate is calculated by the standard curve method (the calculation method is the same as that in Example 1), and the extraction rate can reach 51.9%.

[0042] The corrosion inhibition effect of rosemary extract on steel in hydrochloric acid is detected by electrochemical analysis and surface analysis methods.

[0043] (1) Electrochemical analysis method

[0044] The same electrochemical analysis method as in Example 1 is used to detect the corrosion inhibition effect of rosemary extract on steel in hydrochloric acid. The results show that when 40 mL of rosemary extract is added to every 100 mL of 1 mol / L HCl, the corrosion inhibition rate of steel is 93.7%.

[0045] (2) The morphology analysis of the steel surface adopts the SEM analysis method

[0046] The same SEM analysis method as in Example 1 is used to detect the corrosion inhibition effect of rosemary extract on steel in hydrochloric acid. The results show that the steel surface with rosemary extract added has less corrosion and higher smoothness.

[0047] Example 3

[0048] After crushing rosemary to 300 mesh, weigh 6 g and put it into a 500 mL beaker, add 180 mL of 60% ethanol solution and soak for 200 min, then carry out ultrasonic oscillation for 35 min with an ultrasonic frequency of 300 Hz. Then turn on the BILON-ZCW-1000W microwave oven, set the microwave extraction time to 6 min, the microwave extraction temperature to 50 °C, and the microwave power to 400 w, and extract the active ingredients in rosemary to obtain rosemary extract. After the extraction is completed, use the centrifugation method to collect the rosemary extract.

[0049] The extraction rate was calculated by the standard curve method (the calculation method is the same as that in Example 1), and the extraction rate can reach 52.1%.

[0050] The corrosion inhibition effect of rosemary extract on steel in hydrochloric acid was detected by electrochemical analysis and surface analysis methods.

[0051] (1) Electrochemical analysis method

[0052] The corrosion inhibition effect of rosemary extract on steel in hydrochloric acid was detected by the same electrochemical analysis method as in Example 1. The results showed that when 40 mL of rosemary extract was added to every 100 mL of 1 mol / L HCl, the corrosion inhibition rate of steel was 94.1%.

[0053] (2) The surface morphology of steel was analyzed by SEM analysis method

[0054] The corrosion inhibition effect of rosemary extract on steel in hydrochloric acid was detected by the same SEM analysis method as in Example 1. The results showed that the surface of the steel with rosemary extract added had less corrosion and higher smoothness.

[0055] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An application of rosemary extract in corrosion inhibition of steel in hydrochloric acid, characterized in that: Add 10-50 mL of rosemary extract to every 100 mL of hydrochloric acid solution; the concentration of the hydrochloric acid solution is 1-5 mol / L; The preparation method of the rosemary extract comprises the following steps: Step 1. Crush the rosemary, soak it in an ethanol solution, and then perform ultrasonic oscillation; Step 2. subjecting the mixture after ultrasonic oscillation to microwave extraction to obtain rosemary extract; The parameters of the microwave extraction are set as follows: microwave power 300-500W, microwave extraction temperature 30-60°C, and microwave extraction time 4-8min.

2. The use of the rosemary extract according to claim 1 in the corrosion inhibition of steel in hydrochloric acid, characterized in that: The pulverizing step is pulverizing to 200-300 meshes.

3. The use of the rosemary extract according to claim 1 in the corrosion inhibition of steel in hydrochloric acid, characterized in that: The concentration of the ethanol solution is 40% to 60% v / v; the rosemary is crushed and then soaked in the ethanol solution, and the solid-liquid ratio is 1g:20 to 40mL.

4. The use of the rosemary extract according to claim 1 in the corrosion inhibition of steel in hydrochloric acid, characterized in that: The soaking time is 120 to 240 minutes.

5. The use of the rosemary extract according to claim 1 in inhibiting corrosion of steel in hydrochloric acid, characterized in that: The ultrasonic oscillation time is 20 to 40 minutes, and the ultrasonic oscillation frequency is 300 Hz.

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