HYDROCARBON MIXTURES THAT INCLUDE CORROSION INHIBITOR ADDITIVES AND METHODS FOR INHIBITING CORROSION BY USE THEREOF

Info

Publication number: 20250146138
Type: Application
Filed: Nov 6, 2023
Publication Date: May 8, 2025
Applicant: Saudi Arabian Oil Company (Dhahran)
Inventors: Muthukumar Nagu (Dhahran), Muhammad Imran Ul-haq (Dhahran), Nayef M. Alanazi (Dhahran), Rashed Mohammad Aleisa (Dhahran), Qasim Saleem (Khobar)
Application Number: 18/502,701

Abstract

A hydrocarbon-containing mixture includes a hydrocarbon material including one or more hydrocarbon species, and further includes a corrosion inhibitor additive. Additionally, a method for inhibiting corrosion on a metal surface is disclosed herein.

Description

Description

TECHNICAL FIELD

The present disclosure generally relates to handling and/or processing of hydrocarbons and, more specifically, to corrosion inhibitors utilized in such handling and/or processing of hydrocarbons.

BACKGROUND

Each year, corrosion costs the oil and gas industry trillions of dollars globally. These costs include maintenance, repair, and replacement of corroded equipment, as well as costs associated with environmental damage and cleanup. Corrosion inside refineries can be especially problematic. Inorganic chlorides in crude oil may undergo hydrolysis and form hydrochloric acid (HCl). The HCl may condense and cause corrosion, especially in the overhead area of refinery crude distillation units. Additionally, corrosion in on the internal section of metallic parts used in petroleum product transporting pipelines and storage tanks can be an issue due to water contamination, chlorides, sulfates, bacteria, and dissolved gases present in finished petroleum products such as gasoline, diesel, jet fuel, and kerosene.

SUMMARY

To minimize the corrosion in refinery crude distillation units, pipelines, and storage tanks, corrosion inhibitors may be used. The corrosion inhibitors typically include nitrogen-based compounds, such as imidazolines, dimer trimer acids, and substituted succinic acids. However, despite the use of these corrosion inhibitors, corrosion continues to plagues the oil and gas industry. Therefore, a need exists for alternative types of corrosion inhibitors. As described herein, it has been presently discovered that a particular copolymer, depicted as Chemical Structure #1, may be utilized to achieve enhanced corrosion resistance as compared to other, similar chemical species. Such a corrosion inhibitor additive may be combined with one or more hydrocarbon species (such as crude oil, naphtha, gasoline, etc.) to form a hydrocarbon-containing mixture that may function to reduce corrosion on metal surfaces.

Chemical Structure #1

According to one or more embodiments, a hydrocarbon-containing mixture comprising a hydrocarbon material and a corrosion inhibitor additive. The hydrocarbon material may comprise one or more hydrocarbon species. The corrosion inhibitor additive may have the structure:

wherein x may be a molar fraction chosen from 0.1 to 0.9, and y may be a molar fraction chosen from 0.1 to 0.9.

According to one or more additional embodiments, a method for inhibiting corrosion on a metal surface may comprise contacting a hydrocarbon-containing mixture with a metal substrate. The hydrocarbon-containing mixture may comprise a hydrocarbon material comprising one or more hydrocarbon species, and may further comprise a corrosion inhibitor additive. The corrosion inhibitor additive may have the structure:

wherein x may be a molar fraction chosen from 0.1 to 0.9, and y may be a molar fraction chosen from 0.1 to 0.9.

These and other embodiments are described in more detail in the Detailed Description. It is to be understood that both the foregoing general description and the following detailed description present embodiments of the subject technology, and are intended to provide an overview or framework for understanding the nature and character of the described technology as it is claimed. The accompanying drawings are included to provide a further understanding of the presently disclosed technology and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operations of the presently described technology. Additionally, the drawings and descriptions are meant to be merely illustrative, and are not intended to limit the scope of the claims in any manner.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

FIG. 1 show an NMR analysis of copolymers according to embodiments disclosed and described herein;

FIG. 2 shows an NMR analysis of a comparative example as disclosed and described herein;

FIG. 3 shows an NMR analysis of a comparative example as disclosed and described herein; and

FIG. 4 shows an NMR analysis of a comparative example as disclosed and described herein.

Reference will now be made in greater detail to various embodiments, some embodiments of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of hydrocarbon-containing mixtures that include a hydrocarbon material and a corrosion inhibitor additive. Also disclosed herein are methods which utilize such corrosion inhibitor additives.

According to one or more embodiments, the hydrocarbon material may be any single species or mixture of hydrocarbons, generally in a liquid phase. Such hydrocarbon materials include on or more hydrocarbon species, and are known by those skilled in the art, and particularly those skilled in the art of oil transport and/or processing. Without limitation, the hydrocarbon material by a non-processed crude oil, or be a processed material such as present in refineries and/or other chemical conversion facilities as intermediaries or end products. For example, and without limitation, the hydrocarbon may be chosen from naphtha, gasoline, kerosene, diesel, liquefied petroleum gas (LPG), gas oil, residual fuel oil, lubricating oil base stock, petrochemical feedstocks, aromatics, olefins, light ends, reformates, gas oils, or mixtures thereof.

Generally, the hydrocarbon material is the bulk material in the hydrocarbon-containing mixtures described herein. According to one or more embodiments, the hydrocarbon-containing mixtures may comprise at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.5 wt. %, or even at least 99.9 wt. % of the hydrocarbon materials described herein. Further, as described herein, while the corrosion inhibitor additive may be technically considered a “hydrocarbon,” it is not included as a part of the hydrocarbon material as described herein.

The corrosion inhibitor additives may include copolymers of N-vinylcaprolactam and N-vinylpyrrolidinone. Copolymers of N-vinylcaprolactam and N-vinylpyrrolidinone include copolymers having the structure of Chemical Structure #1, again shown below:

Chemical Structure #1

wherein x is a molar fraction chosen from 0.1 to 0.9, and y is a molar fraction chosen from 0.1 to 0.9. In various embodiments, copolymers of N-vinylcaprolactam and N-vinylpyrrolidinone include copolymers having the structure of Chemical Structure #1, wherein x may be a molar fraction chosen from 0.10 to 0.90, from 0.20 to 0.85, from 0.30 to 0.80, from 0.40 to 0.80, from 0.50 to 0.80, from 0.60 to 0.80, or from 0.70 to 0.80, and y may be a molar fraction chosen from 0.10 to 0.90, from 0.15 to 0.80, from 0.20 to 0.70, from 0.20 to 0.60, from 0.20 to 0.50, from 0.20 to 0.40, or from 0.20 to 0.30. In additional embodiments, x may be a molar fraction of from 0.1 to 0.2, from 0.2 to 0.3, from 0.3 to 0.4, from 0.4 to 0.5, from 0.5 to 0.6, from 0.6 to 0.7, from 0.7 to 0.8, from 0.8 to 0.9, or any combination of two or more of these ranges. In additional embodiments, y may be a molar fraction of from 0.1 to 0.2, from 0.2 to 0.3, from 0.3 to 0.4, from 0.4 to 0.5, from 0.5 to 0.6, from 0.6 to 0.7, from 0.7 to 0.8, from 0.8 to 0.9, or any combination of two or more of these ranges.

Without being bound by theory, it is believed that the corrosion inhibitor additives described and disclosed herein act with corrosion inhibitor properties because of the position of the oxygen atom relative to the hydrocarbon backbone of the copolymer.

In one or more embodiments, the number average molecular weight (Mn) of the copolymers N-vinylcaprolactam and N-vinylpyrrolidinone may be from 500 g/mol to 2000 g/mol. In some embodiments, the number average molecular weight (Mn) of the copolymers N-vinylcaprolactam and N-vinylpyrrolidinone is from 500 g/mol to 2000 g/mol, from 750 g/mol to 2000 g/mol, from 1000 g/mol to 2000 g/mol, from 1250 g/mol to 2000 g/mol, from 1500 g/mol to 2000 g/mol, from 1750 g/mol to 2000 g/mol, from 500 g/mol to 1750 g/mol, from 750 g/mol to 1750 g/mol, from 1000 g/mol to 1750 g/mol, from 1250 g/mol to 1750 g/mol, from 1500 g/mol to 1750 g/mol, 500 g/mol to 1500 g/mol, from 750 g/mol to 1500 g/mol, from 1000 g/mol to 1500 g/mol, from 1250 g/mol to 1500 g/mol, 500 g/mol to 1250 g/mol, from 750 g/mol to 1250 g/mol, from 1000 g/mol to 1250 g/mol, 500 g/mol to 1000 g/mol, from 750 g/mol to 1000 g/mol, or from 500 g/mol to 750 g/mol.

Without being bound by any particular theory, it is believed that the copolymer species of Chemical Structure #1 provides enhanced corrosion resistance to metals as compared with similar chemical species. This is demonstrated in greater detail in the examples that follow. In particular, the copolymer species of Chemical Structure #1 may reduce corrosion in acidic environments, such as those that may be present in the hydrocarbon materials. In some embodiments, the hydrocarbon-containing mixture may have a pH of 7 or less, 6.5 or less, 6 or less, 5.5 or less, or even 5 or less. In various embodiments, the hydrocarbon-containing mixture may have a pH of from 7 to 0, from 6.5 to 0, from 6 to 0, or from 5 to 0.

In one or more embodiments, the hydrocarbon-containing mixture may include from 1 part per million (ppm) to 100 ppm corrosion inhibitor additive. In some embodiments, the hydrocarbon-containing mixture includes from 1 ppm to 100 ppm, from 2 ppm to 100 ppm, from 3 ppm to 100 ppm, from 5 ppm to 100 ppm, from 10 ppm to 100 ppm, from 25 ppm to 100 ppm, from 50 ppm to 100 ppm, from 75 ppm to 100 ppm, 1 ppm to 75 ppm, from 2 ppm to 75 ppm, from 3 ppm to 75 ppm, from 5 ppm to 75 ppm, from 10 ppm to 75 ppm, from 25 ppm to 75 ppm, from 50 ppm to 75 ppm, 1 ppm to 50 ppm, from 2 ppm to 50 ppm, from 3 ppm to 50 ppm, from 5 ppm to 50 ppm, from 10 ppm to 50 ppm, from 25 ppm to 50 ppm, 1 ppm to 25 ppm, from 2 ppm to 25 ppm, from 3 ppm to 25 ppm, from 5 ppm to 25 ppm, from 10 ppm to 25 ppm, 1 ppm to 10 ppm, from 2 ppm to 10 ppm, from 3 ppm to 10 ppm, from 5 ppm to 10 ppm, 1 ppm to 5 ppm, from 2 ppm to 5 ppm, from 3 ppm to 5 ppm, 1 ppm to 5 ppm, from 2 ppm to 5 ppm, from 3 ppm to 5 ppm, 1 ppm to 3 ppm, from 2 ppm to 3 ppm, or from 1 ppm to 2 ppm corrosion inhibitor additive. Without being bound by theory, it is believe that if less than 1 ppm corrosion inhibitor additive is used, there may not be enough corrosion inhibitor to effectively prevent corrosion. However, if more than 100 ppm of corrosion inhibitor is used, it is believed that the corrosion inhibitor additive may create compatibility issues with other additives.

Methods of making the copolymer may include combining N-vinylcaprolactam and N-vinylpyrrolidinone with a free radical initiator and a chain transfer agent to form a reaction mixture under an inert atmosphere. In embodiments, the N-vinylcaprolactam, N-vinylpyrrolidinone, free radical initiator, and chain transfer agent may be in solution. The free radical initiator may be 4,4′-Azobis (4-cyanovaleric acid). Without being bound by theory, the chain transfer agent is believed to reduce the number average molecular weight of the resulting copolymer. The chain transfer agent may be thioglycolic acid. The inert atmosphere may include nitrogen gas.

The reaction mixture may be heated to a temperature of from 30° C. to 100° C. for a time of from 1 hour to 60 hours. In embodiments, the reaction mixture may be heated to a temperature of from 30° C. to 100° C., from 40° C. to 90° C., from 50° C. to 80° C., or from 60° C. to 70° C. for a time of from 1 hour to 60 hours, from 6 hours to 48 hours, from 12 hours to 36 hours, or from 18 hours to 30 hours. The reaction mixture may then be cooled to a temperature of from 1° C. to 30° C. The reaction mixture may be cooled to a temperature of from 1° C. to 30° C., from 2° C. to 20° C., from 3° C. to 15° C., of from 4° C. to 10° C. The cooled reaction mixture may then be washed and dried to obtain the copolymer. The reaction mixture may be washed with diethyl ether. The reaction mixture may be dried using freeze drying.

In embodiments, the synthesis scheme of the copolymer may be that as shown in Chemical Structure #2:

Chemical Structure #2

According to one or more embodiments, methods for inhibiting corrosion on a metal surface may include contacting a hydrocarbon-containing mixture with a metal substrate. The one or more hydrocarbon material and the corrosion inhibitor additive of the hydrocarbon may those discussed hereinabove.

The metal substrate may be, without limitation, refinery crude distillation units, fin-fan coolers, pumps, metal pipes, or metal storage vessels. The metal pipes may include metal pipelines that transport hydrocarbons, pipes present in refineries, or pipes present in other chemical manufacturing facilities. The metal storage vessels may include hydrocarbon storage tanks, reactors, etc.

The metal substrate may be a metal substrate in a refinery. In embodiments, the metal substrate may be a refinery crude distillation unit. As noted hereinabove, inorganic chlorides in crude oil may undergo hydrolysis and form hydrochloric acid (HCl). The HCl may condense and cause corrosion. Thus, refineries, and especially the overhead area of refinery crude distillation units, often undergo corrosion. Therefore, corrosion inhibitor additives may be especially useful in refineries, and more specifically in refinery crude distillation units.

In some embodiments, the metal substrate may include steel, such as carbon steel, stainless steel, alloy steel, or may include other materials such as ductile iron, cast iron, or copper. However, other pure metal and metal alloy materials are contemplated herein.

The hydrocarbon-containing mixture may be at a temperature of from 25° C. to 200° C. In various embodiments, the hydrocarbon-containing mixture may be at a temperature of from 50° C. to 200° C., from 75° C. to 200° C., from 100° C. to 200° C., from 150° C. to 200° C., from 175° C. to 200° C., from 25° C. to 175° C., from 25° C. to 150° C., from 25° C. to 125° C., from 25° C. to 100° C., from 25° C. to 75° C., from 25° C. to 50° C., from 50° C. to 150° C., from 75° C. to 125° C. High temperatures may further contribute to metal corrosion.

In some embodiments, the corrosion inhibitor additive has a corrosion inhibition percent (%) of greater than or equal to 80%, greater than or equal to 82%, or greater than or equal to 85%, as determined by a rotating cage autoclave corrosion test performed in accordance with ASTM G170, the entirety of which is hereby incorporated by reference.

In some embodiments, the corrosion inhibitor additive may have a rating of B+ or above based on spindle test results conducted according to National Association of Corrosion Engineers (NACE) TM 0172, the entirety of which is hereby incorporated by reference.

The present disclosure includes numerous aspects, referred to as Aspects 1-20, as described hereinbelow.

Aspect 1. A hydrocarbon-containing mixture comprising: a hydrocarbon material comprising one or more hydrocarbon species; and a corrosion inhibitor additive, wherein the corrosion inhibitor additive has the structure:

wherein: x is a molar fraction chosen from 0.1 to 0.9; and y is a molar fraction chosen from 0.1 to 0.9.

Aspect 2. The hydrocarbon-containing mixture of aspect 1, wherein hydrocarbon-containing mixture has a pH of 7 or less.

Aspect 3. The hydrocarbon-containing mixture of aspect 1 or aspect 2, wherein the hydrocarbon material is chosen from naphtha, gasoline, kerosene, diesel, liquefied petroleum gas (LPG), gas oil, residual fuel oil, lubricating oil base stock, petrochemical feedstocks, aromatics, olefins, light ends, reformates, gas oils, or mixtures thereof.

Aspect 4. The hydrocarbon-containing mixture of any of aspects 1-3, wherein the hydrocarbon-containing mixture comprises at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.5 wt. %, or even at least 99.9 wt. % of the hydrocarbon materials

Aspect 5. The hydrocarbon-containing mixture of any one of aspects 1-4, wherein the hydrocarbon-containing mixture comprises from 5 ppm to 100 ppm corrosion inhibitor additive.

Aspect 6. The hydrocarbon-containing mixture of any of aspects 1-5, wherein the copolymer is a random copolymer.

Aspect 7. The hydrocarbon-containing mixture of any of aspects 1-6, wherein a number average molecular weight of the copolymer is from 500 g/mol to 2000 g/mol.

Aspect 8. A method for inhibiting corrosion on a metal surface, the method comprising: contacting a hydrocarbon-containing mixture with a metal substrate, wherein the hydrocarbon-containing mixture comprises: a hydrocarbon material comprising one or more hydrocarbon species; and a corrosion inhibitor additive, wherein the corrosion inhibitor additive has the structure:

wherein: x is a molar fraction chosen from 0.1 to 0.9; and y is a molar fraction chosen from 0.1 to 0.9.

Aspect 9. The method of aspect 8, wherein the metal substrate is a metal pipe.

Aspect 10. The method of aspect 8 or aspect 9, wherein the metal substrate is a metal storage vessel.

Aspect 11. The method of any one of aspects 8-10, wherein the metal substrate is in a refinery.

Aspect 12. The method of any one of claims 8-11, wherein the metal substrate is a refinery crude distillation unit.

Aspect 13. The method of any one of claims 8-12, wherein the metal substrate comprises carbon steel, stainless steel, ductile iron, alloy steel, cast iron, copper.

Aspect 14. The method of any of aspects 8-13, wherein the hydrocarbon-containing mixture is at a temperature of from 25° C. to 200° C.

Aspect 15. The method of any of aspects 8-14, wherein hydrocarbon-containing mixture has a pH of 7 or less.

Aspect 16. The method of any of aspects 8-15, wherein the hydrocarbon material is chosen from naphtha, gasoline, kerosene, diesel, liquefied petroleum gas (LPG), gas oil, residual fuel oil, lubricating oil base stock, petrochemical feedstocks, aromatics, olefins, light ends, reformates, gas oils, or mixtures thereof.

Aspect 17. The method of any of aspects 8-16, wherein the hydrocarbon-containing mixture comprises at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.5 wt. %, or even at least 99.9 wt. % of the hydrocarbon materials.

Aspect 18. The method of any one of aspects 8-17, wherein the hydrocarbon-containing mixture comprises from 5 ppm to 100 ppm corrosion inhibitor additive.

Aspect 19. The method of any one of aspects 8-18, wherein the copolymer is a random copolymer.

Aspect 20. The method of any one of aspects 8-19, wherein a number average molecular weight of the copolymer is from 500 g/mol to 2000 g/mol.

EXAMPLES

The following Examples are offered by way of illustration and are presented in a manner such that one skilled in the art should recognize are not meant to be limiting to the present disclosure as a whole or to the appended claims.

Example 1: Synthesis of N-vinylcaprolactam and N-vinylpyrrolidinone Copolymer

4,4′-Azobis (4-cyanovaleric acid) (350 mg, 1.25 mmol) was added to a solution of N-vinylcaprolactam (7.57g, 54.45 mmol), N-vinylpyrrolidinone (2.0 g, 18.15 mmol) and thioglycolic acid (995 mg, 10.8 mmol) in water (42 mL) under N₂. Then the reaction mixture was heated at 63° C. under N₂for 24 h. After the elapsed time, the copolymer mixture was cooled to 5° C. The aqueous phase was washed with diethyl ether (3×20 mL) and freeze-dried to obtain N-vinylcaprolactam and N-vinylpyrrolidinone as a white copolymer (Yield: 91%). The synthesis scheme of this copolymer may be that as shown in Chemical Structure #2:

Chemical Structure #2

The resulting copolymer was as depicted in Chemical Structure #1:

Chemical Structure #1

The incorporation of both monomers into the resulting copolymers was confirmed using NMR analysis, as shown in FIG. 1.

Comparative Example A: Synthesis of N-vinylcaprolactam and N-acryloylpiperidine Copolymer

4,4′-Azobis (4-cyanovaleric acid) (350 mg, 1.25 mmol) was added to a solution of N-vinylcaprolactam (7.57g, 54.45 mmol), N-acryloylpiperidine (2.50 g, 18.15 mmol) and thioglycolic acid (995 mg, 10.8 mmol) in water (42 mL) under N₂. Then the reaction mixture was heated at 63° C. under N₂for 24 h. After the elapsed time, the copolymer mixture was cooled to 5° C. The aqueous phase was washed with diethyl ether (3×20 mL) and freeze-dried to obtain N-vinylcaprolactam and N-acryloylpiperidine as a white copolymer (Yield: 91%).

The resulting copolymer was as depicted in Chemical Structure #3:

Chemical Structure #3

The incorporation of both monomers into the resulting copolymers was confirmed using NMR analysis, as shown in FIG. 2.

Comparative Example B: Synthesis of Comparative Example B: N-vinylcaprolactam and N-acryloylpyrrolidine Copolymer

4,4′-Azobis (4-cyanovaleric acid) (350 mg, 1.25 mmol) was added to a solution of N-vinylcaprolactam (7.57g, 54.45 mmol), N-acryloylpyrrolidine (2.27 g, 18.15 mmol) and thioglycolic acid (995 mg, 10.8 mmol) in water (42 mL) under N₂. Then the reaction mixture was heated at 63° C. under N₂for 24 h. After the elapsed time, the copolymer mixture was cooled to 5° C. The aqueous phase was washed with diethyl ether (3×20 mL) and freeze-dried to obtain N-vinylcaprolactam and N-acryloylpyrrolidine as a white copolymer (Yield: 91%).

The resulting copolymer was as depicted in Chemical Structure #4:

Chemical Structure #4

The incorporation of both monomers into the resulting copolymers was confirmed using NMR analysis, as shown in FIG. 3.

Comparative Example C: Synthesis of N-vinylcaprolactam and N-acryloylmorpholine Copolymer

4,4′-Azobis (4-cyanovaleric acid) (350 mg, 1.25 mmol) was added to a solution of N-vinylcaprolactam (7.57g, 54.45 mmol), N-acryloylmorpholine (2.56 g, 18.15 mmol) and thioglycolic acid (995 mg, 10.8 mmol) in water (42 mL) under N₂. Then the reaction mixture was heated at 63° C. under N₂for 24 h. After the elapsed time, the copolymer mixture was cooled to 5° C. The aqueous phase was washed with diethyl ether (3×20 mL) and freeze-dried to obtain N-vinylcaprolactam and N-acryloylmorpholine as a white copolymer (Yield: 87%).

The resulting copolymer was as depicted in Chemical Structure #5:

Chemical Structure #5

The incorporation of both monomers into the resulting copolymers was confirmed using NMR analysis, as shown in FIG. 4.

As shown hereinabove, it is noted that the chemical structures of Comparative Examples A-C all include carbon atom double bonded to an oxygen atom, as depicted in Chemical Structure #6:

Chemical Structure #6

Without intending to be bound by theory, it is believed that the absence of the carbon atom double bonded to an oxygen atom improves the corrosion inhibition properties of the resulting copolymers.

Example 2: Performance Evaluation with Rotating Cage Autoclave Corrosion Test Method

A rotating cage autoclave corrosion test was performed to measure the corrosion inhibition efficiency of developed formulations. The test was performed in accordance with ASTM G170, the entirety of which is hereby incorporated by reference. 315 mL of synthetic naphtha (10% cyclohexane, 10% toluene, 20% kerosene, 20% octane, 20% iso-octane and 20% heptane) and 35 mL of acid brine, having a composition as shown in Table 1, were prepare to make a 90:10 ratio of hydrocarbon:acid brine ratio test hydrocarbon-containing mixture. Ethanolamine was added in the acid brine solution to attain a pH of 5.2 at 110° C. In the samples including the copolymers of the examples, were added to the test hydrocarbon-containing mixture at a concentration of 100 ppm, except for Sample 1, which was used as a blank without corrosion inhibitor. The test hydrocarbon-containing mixture was then placed into an autoclave cell where a carbon steel C1018 (UNS G10180) metal coupon that had been weighted was been mounted. The composition of the carbon steel metal coupon included 0.60 to 0.90 weight percent (wt. %) manganese, 0.15-0.20 wt. % carbon, from 0.00-0.05 wt. % sulfur, and 0.00-0.04. The test hydrocarbon-containing mixture was then stirred at 500 revolutions per minute (rpm) with continuous nitrogen gas purging for about 30-45 minutes to remove the oxygen in the system and after that increase the rpm of cage speed to 1000 rpm. The autoclave was then closed and the temperature of the test hydrocarbon-containing mixture was increased to 110° C., and the test hydrocarbon-containing mixture was mixed at 1000 rpm for 3 hours. The autoclave was then allowed to cool to 25° C. The metal coupon was then removed. The metal coupon was first washed with a 1:1 mixture of acetone and toluene to remove the corrosion product. The metal coupon was then washed with Clarke's solution, prepared according to the ASTM G1 protocol, the entirety of which is hereby incorporated by reference. The weight of the washed metal coupon was then determined.

TABLE 1 Acid Brine Composition Concentration (in Chemical name ppm) Hydrochloric acid (HCl) 1500 Sulfuric acid (H₂SO₄) 730 Acetic acid (CH₃COOH) 120 Propionic Acid (C₂H₅COOH) 150 Butyric acid (C₃H₇COOH) 125 Valeric acid (C₄H₉COOH) 200 Ammonia (NH₃) 135

The results of the testing were as shown in Table 2.

TABLE 2 Rotating Cage Autoclave Corrosion Rate of Various Samples Concen- Corrosion Corrosion Sample Corrosion inhibitor tration Rate Inhibition Number formulation (ppm) (mpy) (%) 1 None - No Corrosion 0 135 NA Inhibitor Additive Utilized 2 Example 1 100 20.40 85 3 Comparative Example A 100 35.88 73 4 Comparative Example B 100 77.80 42 5 Comparative Example C 100 29.46 78

The corrosion inhibition efficiency percentage was calculated using Equation (I), wherein C represents the corrosion inhibition efficiency percent, W_{Sample 1}represents the weight loss, in milligrams (mg), for Sample 1 (the sample without corrosion inhibitor) and W_Examplerepresents the weight loss, in mg, for a sample using with an example corrosion inhibitors:

$\begin{matrix} C = \frac{(W_{Sample 1}) - (W_{Example})}{(W_{Sample 1})} \times 1 0 0 & Equation (I) \end{matrix}$

The corrosion rate in mils per year (MPY) was calculated using Equation (II), wherein W_Examplerepresents the weight loss for a sample in milligrams, D represents the density of the metal coupon in grams per cubic centimeter, A represents the area of the metal coupon in square inches, and T represents the test duration in hours:

$\begin{matrix} MPY = \frac{5 3 4}{W} \times D \times A \times T & Equation (II) \end{matrix}$

As is shown in Table 2, Sample 2, which utilized the Chemical Structure #1 corrosion inhibitor additive had substantially more corrosion inhibition under the testing procure that the other example compounds.

Example 3: Performance Evaluation with NACE Spindle Test

A National Association of Corrosion Engineers (NACE) spindle test, conducted according to NACE standard TM 0172 and ASTM D665, the entireties of which are hereby incorporated by reference, was also used to evaluate the performance of corrosion inhibitor efficiency for petroleum product pipelines. This test involved adding 300 mL of gasoline to a test beaker and adding a the Example 1 corrosion inhibitor. The beaker was then heated to a temperature of 38±1° C. and a steel test specimen was inserted into the gasoline. The steel test specimen was a threaded steel rod that was 81.0 millimeters (mm) by 12.7 mm (3.19 inches (in) by 0.500 in). Each sample was stirred at 1,000±50 rpm for 30 minutes to ensure complete wetting of the steel test specimen. While being stirred, the temperature-measuring device was temporarily removed, and 30 mL of distilled water was added and discharged onto the bottom of the beaker using a syringe and needle. The measuring device was then replaced. Stirring at a speed of 1,000±50 rpm was continued for 3.5 hours after the water was added, and the temperature was maintained at 38±1° C. Then, the stirring was stopped, and the steel test specimen was allowed to drain. The steel test specimen was then washed with toluene or xylene, and next washed with acetone. Finally, the steel test specimen was examined for corrosion, and rated based on the ratings provided, as described in the NACE test method, as shown in Table 3. A NACE rating of B⁺ or better is sometimes needed for the transportation of hydrocarbons via pipeline.

TABLE 3 Rating of test specimen according to NACE TM 0172 Rating % of test surface corroded A 0 B⁺⁺ Less than 0.1 (2 or 3 spots of no more than 1 mm diameter) B⁺ Less than 5 B 5 to 25 C 25 to 50 D 50 to 75 E 75 to 100

Based on NACE TM 0172 spindle test results (Table 4), the corrosion inhibitor of Example 1 provided excellent corrosion inhibition efficiency. The formulation of Example 1 earned a B⁺ rating, indicating that it is suitable for the transportation of hydrocarbons via pipeline.

TABLE 5 NACE Spindle Test Data Corrosion Rating % Sample inhibitor Concentration (A, B++, B+, B, Corroded Number formulation (PPM) C, D, and E) area 1 None — E 86 2 Example 1 100 B⁺ Less than 5

It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. The term “substantially” is used herein also to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. Thus, it is used to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation, referring to an arrangement of elements or features that, while in theory would be expected to exhibit exact correspondence or behavior, may in practice embody something less than exact.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

It should be understood that where a first component is described as “comprising” or “including” a second component, it is contemplated that, in some embodiments, the first component “consists” or “consists essentially of” the second component. Additionally, the term “consisting essentially of” is used in this disclosure to refer to quantitative values that do not materially affect the basic and novel characteristic(s) of the disclosure.

It should be understood that any two quantitative values assigned to a property or measurement may constitute a range of that property or measurement, and all combinations of ranges formed from all stated quantitative values of a given property or measurement are contemplated in this disclosure.

While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

Claims

1. A hydrocarbon-containing mixture comprising:

a hydrocarbon material comprising one or more hydrocarbon species; and

a corrosion inhibitor additive, wherein the corrosion inhibitor additive has the structure:

wherein: x is a molar fraction chosen from 0.1 to 0.9; and y is a molar fraction chosen from 0.1 to 0.9.

2. The hydrocarbon-containing mixture of claim 1, wherein hydrocarbon-containing mixture has a pH of 7 or less.

3. The hydrocarbon-containing mixture of claim 1, wherein the hydrocarbon material is chosen from naphtha, gasoline, kerosene, diesel, liquefied petroleum gas (LPG), gas oil, residual fuel oil, lubricating oil base stock, petrochemical feedstocks, aromatics, olefins, light ends, reformates, gas oils, or mixtures thereof.

4. The hydrocarbon-containing mixture of claim 1, wherein the hydrocarbon-containing mixture comprises at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.5 wt. %, or even at least 99.9 wt. % of the hydrocarbon materials.

5. The hydrocarbon-containing mixture of claim 1, wherein the hydrocarbon-containing mixture comprises from 5 ppm to 100 ppm corrosion inhibitor additive.

6. The hydrocarbon-containing mixture of claim 1, wherein the copolymer is a random copolymer.

7. The hydrocarbon-containing mixture of claim 1, wherein a number average molecular weight of the copolymer is from 500 g/mol to 2000 g/mol.

8. A method for inhibiting corrosion on a metal surface, the method comprising:

contacting a hydrocarbon-containing mixture with a metal substrate, wherein the hydrocarbon-containing mixture comprises: a hydrocarbon material comprising one or more hydrocarbon species; and a corrosion inhibitor additive, wherein the corrosion inhibitor additive has the structure:

wherein: x is a molar fraction chosen from 0.1 to 0.9; and y is a molar fraction chosen from 0.1 to 0.9.

9. The method of claim 8, wherein the metal substrate is a metal pipe.

10. The method of claim 8, wherein the metal substrate is a metal storage vessel.

11. The method of claim 8, wherein the metal substrate is in a refinery.

12. The method of claim 8, wherein the metal substrate is a refinery crude distillation unit.

13. The method of claim 8, wherein the metal substrate comprises carbon steel, stainless steel, ductile iron, alloy steel, cast iron, copper.

14. The method of claim 8, wherein the hydrocarbon-containing mixture is at a temperature of from 25° C. to 200° C.

15. The method of claim 8, wherein hydrocarbon-containing mixture has a pH of 7 or less.

16. The method of claim 8, wherein the hydrocarbon material is chosen from naphtha, gasoline, kerosene, diesel, liquefied petroleum gas (LPG), gas oil, residual fuel oil, lubricating oil base stock, petrochemical feedstocks, aromatics, olefins, light ends, reformates, gas oils, or mixtures thereof.

17. The method of claim 8, wherein the hydrocarbon-containing mixture comprises at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.5 wt. %, or even at least 99.9 wt. % of the hydrocarbon materials.

18. The method of claim 8, wherein the hydrocarbon-containing mixture comprises from 5 ppm to 100 ppm corrosion inhibitor additive.

19. The method of claim 8, wherein the copolymer is a random copolymer.

20. The method of claim 8, wherein a number average molecular weight of the copolymer is from 500 g/mol to 2000 g/mol.