Environment-friendly corrosion inhibitor based on water-soluble cardanol, preparation method and application

Abstract

The invention relates to an environment-friendly corrosion inhibitor based on water-soluble cardanol, and relates to the field of oil field corrosion inhibitor preparation. The problems that an existing corrosion inhibitor is poor in environmental protection property and inconvenient to operate are mainly solved. The anacardol composition comprises the following raw material components in percentage by mass: 5-20% of anacardol extract; 1%-10% of glycidyl aldehyde; 2%-15% of acetic acid; 0.05%-0.5% of a catalyst; 2%-10% of a water-soluble auxiliary agent; the preparation method comprises the following steps: (1) preparing the cardanol extract; and (2) carrying out condensation polymerization on the cardanol extract, glycidyl aldehyde, acetic acid and a catalyst in proportion under reaction conditions to obtain the cardanol-based corrosion inhibitor, (3) adding a water-soluble additive in the polycondensation reaction process; and (4) separating, washing, drying and grinding the obtained corrosion inhibitor to obtain purified corrosion inhibitor powder based on water-soluble cardanol. The environment-friendly corrosion inhibitor meets the dual requirements of oil field application on environmental protection and corrosion inhibition performance.

Description

Technical Field

[0001] This invention relates to the field of oilfield corrosion inhibitor preparation technology, and in particular to an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, its preparation method and application. Background Technology

[0002] Currently, in the field of oil production engineering, well acidizing technology is widely used to increase oil well production. By injecting acid into the well, the permeability of the oil reservoir can be effectively improved, thereby increasing production. However, the injection of acid also brings a significant problem—corrosion of oil and gas well tubing and downhole metal facilities. If this corrosion problem is not effectively controlled, it can lead to damage to downhole tools, causing construction accidents and resulting in huge economic losses. To solve this problem, adding acidizing corrosion inhibitors during the acidizing process is considered an effective method to prevent corrosion of downhole equipment. Currently, most common corrosion inhibitors on the market are organic compounds, such as benzotriazoles, phosphate esters, and imidazoline compounds. Although these corrosion inhibitors have good corrosion inhibition effects in oilfield applications, most are difficult to biodegrade and have a certain degree of environmental pollution. Patent CN117865897A discloses a method for preparing an N,N-hexane bis(2-benzimidazolyl)-octadecyl quaternary ammonium salt corrosion inhibitor. This inhibitor exhibits good corrosion inhibition performance in oil and gas wells with complex corrosive environments. However, the synthetic raw material, polyphosphoric acid, is a toxic reagent that can cause water pollution and other problems. Patent CN117512600A discloses a high-temperature acidification corrosion inhibitor with excellent high-temperature corrosion resistance. However, its synthetic raw material, propynyl alcohol, is highly toxic and can also pollute the environment. Therefore, there is an urgent need to develop an environmentally friendly corrosion inhibitor that can effectively inhibit metal corrosion while minimizing environmental impact.

[0003] Cashew shells, a byproduct of cashew processing, are rich in phenolic compounds and possess excellent antioxidant and anti-corrosion properties. Utilizing cashew shells to prepare corrosion inhibitors not only enables the high-value utilization of resources but also reduces production costs. However, most reported cashew phenol corrosion inhibitors are oil-soluble, making them inconvenient to handle. Therefore, developing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol and its preparation method is of significant practical importance for meeting the dual requirements of environmental protection and corrosion inhibition performance in oilfield applications. Summary of the Invention

[0004] This invention provides an environmentally friendly corrosion inhibitor based on water-soluble cashew nut shell phenols (DPF), overcoming the problems of poor environmental performance and inconvenient operation of existing corrosion inhibitors in the prior art. The purpose of this invention is to propose an environmentally friendly corrosion inhibitor based on water-soluble cashew nut shell phenols (DPF) that meets the dual requirements of environmental protection and corrosion inhibition performance in oilfield applications, and is easy to operate. This invention also provides a method for preparing and applying this environmentally friendly corrosion inhibitor based on water-soluble cashew nut shell phenols (DPF).

[0005] To achieve the above objectives, the first aspect of the present invention provides an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the raw material components and the mass percentage of each component of which are as follows:

[0006] Cashew nut extract: 5%–20%; glycidaldehyde: 1%–10%; acetic acid: 2%–15%; catalyst: 0.05%–0.5%; water-soluble adjuvants: 2%–10%.

[0007] Preferably, the raw materials for preparing the cashew phenol extract are cashew shells and organic solvents.

[0008] Preferably, the mass ratio of cashew nut shells to organic solvent is 1:2 to 1:20.

[0009] Preferably, the organic solvent is at least one of ethanol, methanol, or acetone.

[0010] Preferably, the catalyst is at least one of sulfuric acid, zinc chloride, or sodium nitrate.

[0011] Preferably, the water-soluble additive is at least one of polyethylene glycol, polyvinylpyrrolidone, and hydroxyethyl cellulose.

[0012] A second aspect of this invention provides a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, comprising the following steps:

[0013] (1) Preparation of cashew nut extract: Cashew shells are mixed with organic solvents in proportion, and cashew nut extract is obtained through crushing, extraction, pressing, filtration, concentration and refining.

[0014] (2) The cashew extract, glycidaldehyde, acetic acid and catalyst obtained in step (1) are subjected to polycondensation reaction under reaction conditions in proportion to obtain a corrosion inhibitor based on cashew phenol.

[0015] (3) During the polycondensation reaction in step (2), a water-soluble additive is added to improve the water solubility of the resulting corrosion inhibitor;

[0016] (4) The corrosion inhibitor obtained in step (3) is separated, washed, dried and ground to obtain purified corrosion inhibitor powder based on water-soluble cashew phenol.

[0017] Preferably, the cashew nut shell particle size in step (1) is 1-10 mm.

[0018] Preferably, the reaction conditions for the polycondensation reaction in step (2) are: temperature: 60-120℃; reaction time: 1-10 hours.

[0019] Preferably, the detergent in step (4) is water or an organic solvent.

[0020] Preferably, the organic solvent is at least one of ethanol, methanol, or acetone.

[0021] Preferably, the drying process in step (4) adopts a vacuum drying method, and the grinding process adopts an ultrafine grinder.

[0022] The third aspect of this invention provides an application of an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol in the corrosion protection of metallic materials in the field of oilfield engineering technology.

[0023] The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol provided by this invention mainly includes two aspects in its corrosion inhibition mechanism: adsorption and passivation.

[0024] Adsorption: Cashew phenol molecules contain active functional groups such as hydroxyl (~OH) and methoxy (~OCH3), which can be adsorbed onto metal surfaces through hydrogen bonding or coordination to form a dense protective film. This protective film effectively blocks direct contact between the metal and the corrosive medium, thereby slowing down the corrosion process.

[0025] Passivation effect: Cashew nutshellol molecules adsorbed on the metal surface can alter the surface chemical and electrochemical properties of the metal, making it more stable against corrosive media. Furthermore, cashew nutshellol molecules may form stable complexes with oxides or hydroxides on the metal surface, further enhancing the metal's passivation capability.

[0026] Based on the above mechanism, the water-soluble cashew phenol corrosion inhibitor prepared in this invention can significantly reduce the corrosion rate of metals and extend their service life. Simultaneously, this corrosion inhibitor has good water solubility and biodegradability, which can reduce environmental pollution and is suitable for acidizing and enhanced oil production measures in oilfield engineering.

[0027] The present invention has at least the following beneficial effects:

[0028] This article presents a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, which has the following advantages:

[0029] (1) Using cashew shells as raw materials to prepare corrosion inhibitors not only realizes the high-value utilization of waste biological resources, but also reduces production costs. The prepared cashew phenol corrosion inhibitor has good water solubility and biodegradability, reducing environmental pollution and conforming to the concept of green environmental protection.

[0030] (2) The corrosion inhibitor based on cashew phenol of the present invention has been experimentally proven to have excellent corrosion inhibition and protection effect on metal materials, and can significantly extend the service life of metal equipment.

[0031] (3) The preparation process provided by the present invention is simple and controllable, and the raw materials are widely available, making it suitable for industrial production.

[0032] Laboratory experiments showed that corrosion tests on N80 steel sheets were conducted at 90℃ in an acidic medium containing HCl and HF. The results showed that adding 0.5% of the water-soluble cashew phenol corrosion inhibitor of this invention significantly reduced the corrosion rate of the steel sheets to only 1.72 g / (m2·h). The performance indicators met the requirements of industry standards, indicating that it has excellent anti-corrosion protection for steel materials in a high-temperature acidic environment.

[0033] The prepared water-soluble cashew phenol corrosion inhibitor can be widely used in the corrosion protection of metallic materials in the field of oilfield engineering technology, and has good application prospects and economic benefits. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used in the following examples are commercially available unless otherwise specified.

[0036] This invention is not limited to the specific embodiments listed below. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any modifications or alterations made to the design structure and concept of this invention fall within the protection scope of this invention. It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0037] An environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the raw material components and the mass percentage of each component are as follows:

[0038] Cashew nut extract: 5%–20%; glycidaldehyde: 1%–10%; acetic acid: 2%–15%; catalyst: 0.05%–0.5%; water-soluble adjuvants: 2%–10%.

[0039] The cashew nut extract is prepared by mixing cashew shells with an organic solvent in a certain proportion, and then proceeding through crushing, extraction, pressing, filtration, concentration, and purification to obtain the cashew nut extract; the mass ratio of cashew shells to organic solvent is 1:2 to 1:20; the organic solvent is at least one of ethanol, methanol, or acetone; and the cashew shell particle size is 1 to 10 mm.

[0040] The catalyst is at least one of sulfuric acid, zinc chloride, and sodium nitrate.

[0041] The water-soluble additive is at least one of polyethylene glycol, polyvinylpyrrolidone, and hydroxyethyl cellulose.

[0042] This invention also provides a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, comprising the following steps:

[0043] (1) Preparation of cashew phenol extract:

[0044] Cashew shells are mixed with an organic solvent in a certain proportion, and then subjected to steps such as crushing, extraction, pressing, filtration, concentration and refining to obtain cashew phenol extract; the mass ratio of cashew shells to organic solvent is 1:2 to 1:20; the organic solvent is at least one of ethanol, methanol or acetone; the cashew shell particle size is 1 to 10 mm.

[0045] (2) The cashew extract, glycidaldehyde, acetic acid and catalyst obtained in step (1) are subjected to polycondensation reaction under the reaction conditions in proportion to obtain a corrosion inhibitor based on cashew phenol; Polycondensation reaction conditions: temperature: 60~120℃; reaction time: 1~10 hours;

[0046] (3) During the polycondensation reaction in step (2), a water-soluble additive is added to improve the water solubility of the resulting corrosion inhibitor;

[0047] (4) The corrosion inhibitor obtained in step (3) is separated, washed, dried, and ground to obtain purified corrosion inhibitor powder based on water-soluble cashew phenol. The washing agent is water or an organic solvent; the organic solvent is at least one of ethanol, methanol, or acetone; the drying process is carried out by vacuum drying, and the grinding process is carried out by an ultrafine grinder.

[0048] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be noted that these embodiments are for illustrative purposes only and do not limit the scope of protection of this invention. The equipment and raw materials used in the embodiments are all commercially available products.

[0049] Example 1

[0050] This embodiment describes a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the specific steps of which are as follows:

[0051] (1) The cashew shells are crushed to a particle size of 1-5 mm, mixed with ethanol at a mass ratio of 1:10, and extracted for 12 hours; then the extract is extracted; the extract is filtered, concentrated, and then refined to obtain cashew phenol extract.

[0052] (2) Take 10g of cashew phenol extract, 3g of glycidaldehyde, 5g of acetic acid and 0.2g of sulfuric acid, and perform polycondensation reaction at 80℃ for 4 hours;

[0053] During the reaction, 4g of polyethylene glycol was added as a water-soluble additive to improve the water solubility of the corrosion inhibitor.

[0054] (3) The polycondensation product was subjected to centrifugation, water washing, vacuum drying and ultrafine grinding in sequence to obtain purified water-soluble cashew phenol corrosion inhibitor powder.

[0055] Example 2

[0056] This embodiment describes a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the specific steps of which are as follows:

[0057] (1) The cashew shells are crushed to a particle size of 1-5 mm, mixed with methanol at a mass ratio of 1:8, and extracted for 10 hours; then the extract is extracted; the extract is filtered, concentrated, and then refined to obtain cashew phenol extract.

[0058] (2) Take 15g of cashew phenol extract, 4g of glycidaldehyde, 6g of acetic acid and 0.3g of zinc chloride, and perform polycondensation reaction at 90℃ for 5 hours;

[0059] During the reaction, 5g of hydroxyethyl cellulose was added as a water-soluble additive to improve the water solubility of the corrosion inhibitor.

[0060] (3) The polycondensation product was subjected to centrifugation, water washing, vacuum drying and ultrafine grinding in sequence to obtain purified water-soluble cashew phenol corrosion inhibitor powder.

[0061] Example 3

[0062] This embodiment describes a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the specific steps of which are as follows:

[0063] (1) The cashew shells are crushed to a particle size of 2-4 mm, mixed with methanol at a mass ratio of 1:8, and extracted for 10 hours; then the extract is extracted; the extract is filtered, concentrated, and then refined to obtain cashew phenol extract.

[0064] (2) Take 8g of cashew phenol extract, 5g of glycidaldehyde, 10g of acetic acid and 0.1g of zinc chloride, and perform polycondensation reaction at 85℃ for 3.5 hours;

[0065] During the reaction, 3g of polyvinylpyrrolidone was added as a water-soluble additive to improve the water solubility of the corrosion inhibitor.

[0066] (3) The polycondensation product was subjected to centrifugation, water washing, vacuum drying and ultrafine grinding in sequence to obtain purified water-soluble cashew phenol corrosion inhibitor powder.

[0067] Example 4

[0068] This embodiment describes a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the specific steps of which are as follows:

[0069] (1) The cashew shells are crushed to a particle size of 3-5 mm, mixed with ethanol at a mass ratio of 1:12, and extracted for 14 hours; then the extract is extracted; the extract is filtered, concentrated, and then refined to obtain cashew phenol extract.

[0070] (2) Take 15g of cashew phenol extract, 2g of glycidaldehyde, 4g of acetic acid and 0.3g of sodium nitrate, and perform polycondensation reaction at 90℃ for 5 hours;

[0071] During the reaction, 6g of hydroxyethyl cellulose was added as a water-soluble additive to improve the water solubility of the corrosion inhibitor.

[0072] (3) The polycondensation product was subjected to centrifugation, water washing, vacuum drying and ultrafine grinding in sequence to obtain purified water-soluble cashew phenol corrosion inhibitor powder.

[0073] Example 5

[0074] This embodiment describes a method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, the specific steps of which are as follows:

[0075] (1) Crush cashew shells to a particle size of 4-6 mm, mix them with acetone at a mass ratio of 1:15, and extract for 8 hours; then press to obtain an extract; filter, concentrate, and then refine the extract to obtain cashew phenol extract.

[0076] (2) Take 12g of cashew phenol extract, 8g of glycidaldehyde, 6g of acetic acid and 0.05g of sulfuric acid, and perform polycondensation reaction at 75℃ for 6 hours;

[0077] During the reaction, 5g of polyethylene glycol-400 was added as a water-soluble additive to improve the water solubility of the corrosion inhibitor.

[0078] (3) The polycondensation product was subjected to centrifugation, water washing, vacuum drying and ultrafine grinding in sequence to obtain purified water-soluble cashew phenol corrosion inhibitor powder.

[0079] The above embodiments successfully prepared an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol. This corrosion inhibitor exhibits excellent anti-corrosion protection for metallic materials, significantly reducing the corrosion rate and extending the service life of metal equipment. Simultaneously, it possesses good water solubility and biodegradability, which helps reduce environmental pollution. The preparation process provided by this invention is simple and controllable, suitable for industrial production.

[0080] This invention is not limited to the embodiments described above. Any improvements, equivalent substitutions, and modifications made to the embodiments within the spirit and principles of this invention should be included within the scope of protection of this invention. For example, the ratio of cashew nut shells to solvent, extraction time, polycondensation reaction conditions, etc., can be adjusted to optimize the performance of the corrosion inhibitor.

[0081] Test Example 1

[0082] This invention evaluates the corrosion inhibition performance of an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol.

[0083] To evaluate the corrosion inhibition performance of the water-soluble cashew phenol corrosion inhibitor of the present invention, the following experiments were conducted:

[0084] Evaluation of corrosion inhibition effect:

[0085] Experimental conditions: This experiment was conducted at a high temperature of 90℃ using a coagulant solution containing 12% HCl and 3% HF as the corrosion medium to investigate the corrosion inhibition performance of different formulations of water-soluble cashew nut shell corrosion inhibitors on N80 steel sheets. In the experiment, the N80 steel sheets were immersed in the acid solution for 4 hours. The mass loss before and after corrosion was calculated by weighing, and the corrosion rate of each embodiment was obtained. The results were compared with the blank group to evaluate the corrosion inhibition effect of the inhibitors. The experimental data are shown in Table 1.

[0086] Experimental results show that corrosion tests on N80 steel sheets conducted at 90℃ in a sub-acidic medium containing HCl and HF significantly reduced the corrosion rate of the steel sheets by adding 0.5% water-soluble cashew nut shell corrosion inhibitor. Among the five tested examples, Example 4 exhibited the best corrosion inhibition performance, with a corrosion rate of only 1.72 g / (m²). 2 The concentration of ·h) was significantly lower than the 18.62 g / (m) in the control group. 2 The performance indicators meet the requirements of industry standards, indicating that it has excellent anti-corrosion protection for steel materials in high-temperature acidic environments, and is expected to be widely used in oil and gas field acidification operations.

[0087] Table 1 Corrosion test data of corrosion inhibitors

[0088]

[0089] This invention relates to an environmentally friendly corrosion inhibitor based on water-soluble cashew nut shells. Utilizing cashew shells as a raw material, the corrosion inhibitor not only achieves high-value utilization of waste biological resources but also reduces production costs. The prepared cashew nut shell corrosion inhibitor exhibits good water solubility and biodegradability, reducing environmental pollution and aligning with the concept of green environmental protection.

[0090] The corrosion inhibitor based on cashew phenol of this invention has been experimentally proven to have excellent corrosion inhibition and protection effects on metal materials, and can significantly extend the service life of metal equipment.

[0091] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An environmentally friendly corrosion inhibitor based on water-soluble cashew phenol, characterized in that: The raw material composition and the mass percentage of each component are as follows: Cashew nut extract: 5%–20%; glycidaldehyde: 1%–10%; acetic acid: 2%–15%; catalyst: 0.05%–0.5%; water-soluble adjuvants: 2%–10%.

2. The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 1, characterized in that: The raw materials for preparing the cashew phenol extract are cashew shells and organic solvents.

3. The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 2, characterized in that: The mass ratio of cashew shells to organic solvent is 1:2 to 1:

20.

4. The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 2, characterized in that: The organic solvent is at least one of ethanol, methanol, or acetone.

5. The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 1, characterized in that: The catalyst is at least one of sulfuric acid, zinc chloride, and sodium nitrate.

6. The environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 1, characterized in that: The water-soluble additive is at least one of polyethylene glycol, polyvinylpyrrolidone, and hydroxyethyl cellulose.

7. A method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to any one of claims 1 to 6, characterized in that: Includes the following steps: (1) Preparation of cashew nut extract: Cashew shells are mixed with organic solvent in proportion, and cashew nut extract is obtained by crushing, soaking, pressing, filtering, concentrating and refining. (2) The cashew extract obtained in step (1), glycidaldehyde, acetic acid and catalyst are subjected to polycondensation reaction under reaction conditions in proportion to obtain a corrosion inhibitor based on cashew phenol. (3) During the polycondensation reaction in step (2), a water-soluble additive is added to improve the water solubility of the resulting corrosion inhibitor; (4) The corrosion inhibitor obtained in step (3) is separated, washed, dried and ground to obtain purified corrosion inhibitor powder based on water-soluble cashew phenol.

8. The method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 7, characterized in that: In step (1), the cashew shell particle size is 1-10 mm.

9. The method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 7, characterized in that: The reaction conditions for the polycondensation reaction in step (2) are: temperature: 60-120℃; reaction time: 1-10 hours.

10. The method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 7, characterized in that: The detergent in step (4) is water or an organic solvent.

11. The method for preparing the environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 10, characterized in that: The organic solvent is at least one of ethanol, methanol, or acetone.

12. The method for preparing an environmentally friendly corrosion inhibitor based on water-soluble cashew phenol according to claim 7, characterized in that: The drying process in step (4) adopts vacuum drying method; The grinding process uses an ultrafine grinder.

13. The application of the water-soluble cashew phenol-based environmentally friendly corrosion inhibitor according to any one of claims 1-6 in the field of corrosion protection of metallic materials in oilfield engineering technology.

Images