Lubricant compositions comprising diethylenetriaminepentaacetic acid as corrosion inhibitors

Abstract

Embodiments of a lubricant composition may include an oil lubricant and a corrosion inhibitor, wherein the corrosion inhibitor may be diethylene triamine pentaacetic acid (DTPA).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 359,591, filed on July 8, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0003] Embodiments described herein relate generally to corrosion inhibition, and more particularly to lubricant compositions having corrosion inhibitors. Background Art

[0004] Acid copolymer resins (ACRs) can be used to produce packaging materials, building panels, and water pipes, among other things. As a result of this utility, there is a demand for ACRs throughout the world. ACR production typically involves the use of corrosive materials. Over time, these corrosive materials can corrode components of the ACR production unit, requiring replacement of these components. Replacement of these components can increase the cost of ACR production. Therefore, there is a need to improve the production of ACRs, and more specifically, to improve the protection of ACR production units from the effects of corrosion. Summary of the invention

[0005] Embodiments of the present disclosure meet this need by including diethylenetriaminepentaacetic acid (DTPA) in lubricant compositions to inhibit corrosion.

[0006] According to one or more embodiments of the present disclosure, a lubricant composition is provided, which comprises: an oil lubricant and a corrosion inhibitor, wherein the corrosion inhibitor is DTPA.

[0007] Additional features and advantages will be set forth in the following detailed description, and in part will become apparent to those skilled in the art from that description or may be learned by practicing the embodiments described herein, including the drawings, the following detailed description, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A reactor system according to one or more embodiments of the present disclosure is schematically depicted.

[0009] When describing Figure 1 While the simplified schematic illustration of FIG. 1 does not include many valves, temperature sensors, electronic controllers, etc. that may be used and are well known to those of ordinary skill in the art, it should be understood that these components are within the scope of the present disclosure.

[0010] Reference will now be made in greater detail to various embodiments, some of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION

[0011] The specific embodiments of the application will now be described. However, the present disclosure can be implemented in different forms and should not be construed as being limited to the embodiments set forth in the present disclosure. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0012] The present disclosure relates to lubricant compositions. For example and as described herein, the lubricant composition may include a lubricating oil and a corrosion inhibitor. The corrosion inhibitor may be DTPA. Such lubricant compositions including DTPA may be particularly suitable for free radical polymerization processes where bronze packing rings are used in compressors.

[0013] In one or more embodiments, the lubricant composition may include an oil lubricant. The oil lubricant may include at least one oil, and may contain one or more additives, for example, one or more lubricants. Additives may be added to improve lubricity, fluidity, thermal stability and / or other characteristics. In one or more embodiments, at least one oil may be a viscous liquid having a viscosity that is improved compared to water at the same temperature and pressure, and it is derived from petroleum. At least one oil may provide lubrication and reduce friction between the moving surfaces of a rotating mechanism and / or a reciprocating mechanism. In one or more embodiments, the oil may be one or more mineral oils and polyalkylene glycol base oils.

[0014] In some embodiments, the oil may have a 50 mm 2 / s to 200mm 2 / s kinematic viscosity. For example, oil may have a kinematic viscosity of 50 mm 2 / s to 100mm 2 / s、100mm 2 / s to 150mm 2 / s、150m 2 / s to 200mm 2 / s or any combination of these ranges.

[0015] As described herein, in one or more embodiments, the lubricant composition may include a corrosion inhibitor. In some embodiments, the lubricant composition may include a corrosion inhibitor in an amount of 0.5 wt % to about 20 wt %. For example, the lubricant composition may include a corrosion inhibitor in an amount of 0.5 wt % to 1 wt %, 1 wt % to 5 wt %, 5 wt % to 10 wt %, 10 wt % to 15 wt %, 15 wt % to 20 wt %, or any combination of these ranges. In some embodiments, the lubricant composition may include a corrosion inhibitor in an amount of 1 wt % to 17.5 wt %, 1.5 wt % to 15 wt %, 2 wt % to 12.5 wt %, or 2.5 wt % to 10 wt %. In some embodiments, the lubricant composition may include a DTPA in an amount of 2.5 wt % to 10 wt %.

[0016] In one or more embodiments, the lubricant composition can be used in a method for reducing corrosion, the method comprising exposing a metal component to a solution containing the lubricant composition and (meth)acrylic acid, wherein the lubricant composition reduces metal corrosion. As used in this disclosure, the term "(meth)acrylic acid" may be used to refer to methacrylic acid or acrylic acid or both.

[0017] In one or more embodiments, the solution containing the lubricant composition may include a co-solvent. The co-solvent may include a carboxylic acid, an alcohol, or a combination thereof. In some embodiments, the co-solvent may include methanol.

[0018] In one or more embodiments, the metal component may include bronze packing rings. In one or more embodiments, the bronze packing rings may be part of a compressor. In some embodiments, the bronze packing rings may be used in a high pressure polyethylene reactor such as Figure 1 Part of a compressor unit used in a high pressure polyethylene reactor (schematically depicted in FIG. ).

[0019] In one or more embodiments, the lubricant composition can be used in a free radical polymerization process comprising polymerizing ethylene monomer and optionally (meth)acrylic acid via free radical polymerization in a high pressure polyethylene reactor having a compressor with bronze packing rings in the presence of the lubricant composition. Free radical polymerization processes for producing ethylene-based polymers are typically conducted at elevated pressures (typically at least 100 MPa). For example, the free radical polymerization process can be conducted at least 200 MPa, at least 300 MPa, at least 400 MPa, or at least 500 MPa.

[0020] The following definitions may aid in understanding the operation of example reactor systems that may be suitable for use with the lubricant compositions described herein.

[0021] As used herein, the term "feed" or "feed stream" refers to fresh and / or recycled reactants added to a reaction zone at the inlet of the reaction zone.

[0022] As used herein, the term "reaction zone" refers to the zone of the reactor where polymerization is initiated or reinitiated by adding free radicals and / or decomposing components into free radicals and / or components that generate free radicals.

[0023] As used herein, the term "reactor system" refers to a component (device) for polymerizing and separating polymers. Such components / devices include, but are not limited to, one or more reactors, ultra-high pressure compressors, main compressors, and booster compressors. The reactor system typically includes at least one reactor, such as a tubular reactor, an autoclave reactor, or any combination thereof.

[0024] As used herein, the term "injection point" refers to the entry location of a device (used in a polymerization process) where a feed stream is added to the device.

[0025] As used herein, the term "pressurizing" refers to increasing the pressure of a liquid or feed to a higher pressure level.

[0026] As used herein, the term "compression system" refers to a compression device that increases the pressure of a vapor (e.g., ethylene vapor below or above its critical point) to a higher pressure level. Feeding comonomers may include pressurizing the reactive comonomers using an ultra-high pressure reciprocating piston pump and feeding the reactive comonomers directly into the feed stream of the reactor zone and / or the reaction zone, and / or feeding the comonomers by a combination of pressurizing with a high pressure pump and further compressing with a reciprocating piston compressor (e.g., an ultra-high pressure compressor, a main compressor, and / or a booster compressor).

[0027] As used herein, the term "compression" refers to increasing the pressure of a vapor (eg, ethylene vapor below or above its critical point) to a higher pressure level.

[0028] A booster compressor is a device that compresses the low pressure recycle, e.g. from a low pressure separator, to the required pressure level at the inlet side of the main compressor. This compression can be performed in one or more compression stages and can be combined with intercooling. A booster compressor can consist of a single or multiple compressor frames and can potentially be combined with a main compressor frame.

[0029] The main compressor is a device that compresses, for example: a) fresh incoming ethylene, and / or b) low pressure recycle from a booster compressor; each to the required pressure level on the inlet side of the hypercompressor. This compression can be performed in one or more compression stages and can be combined with intercooling. The main compressor can consist of a single or multiple compressor frames and can potentially be combined with a booster compressor frame.

[0030] A super high pressure compressor or secondary compressor is a device that compresses, for example, monomers from a primary compressor to the pressure level required for feeding to a reactor at its inlet pressure set point. This compression can be performed in one or more compression stages and can be combined with intermediate cooling. A super high pressure compressor typically comprises a plunger reciprocating compressor and can consist of a single or multiple compressor frames.

[0031] Reference now Figure 1 , schematically depicts an example reactor system that may be suitable for use with the lubricant compositions described herein. It should be understood that not Figure 1 All parts of the appended claims should be interpreted as being essential to the claimed subject matter. In addition, although the lubricant composition in the appended claims is Figure 1 Although described in the context of the present invention, such listed compositions should be understood to be applicable to other systems, as understood by those skilled in the art.

[0032] Figure 1 A general flow diagram of a high pressure polymerization process is shown, wherein the reactor system contains a reactor 26, which can be a tubular reactor, an autoclave reactor, or a combination of a tubular reactor and an autoclave reactor. Stream (1) represents fresh monomer supplement, which is compressed into stream (2) by a main compressor (22) together with the outlet of a booster compressor (20). The fresh monomer supplement may contain ethylene. Stream (2) is combined with a high pressure recycle stream (7) from a high pressure separator (28) in an ultra-high pressure compressor inlet stream (3) and fed to the suction port of an ultra-high pressure compressor (24). The ultra-high pressure compressor compresses the monomer feed stream to a level sufficient to feed to a reactor (26). Stream 4 represents a compressed monomer feed stream fed to a reactor (26). The high pressure separator (28) separates the product vapor (5) into a polymer-rich stream (6) and a stream (7) rich in unreacted monomers. Stream (7) is recycled for reuse in the process and stream (6) is sent to a low pressure separator (30). The low pressure separator (30) separates the vapor (6) into a monomer stream (8) which flows to a booster compressor (20) and a polymer stream (9) for further processing.

[0033] In one or more embodiments, a lubricant composition as described herein can be used in an ultra-high pressure compressor (24). For example, a lubricant composition comprising an oil lubricant and a corrosion inhibitor comprising DTPA can be exposed to a metal component of the ultra-high pressure compressor (24). In some embodiments, the metal component of the ultra-high pressure compressor (24) can include a bronze packing ring.

[0034] Test Method

[0035] Corrosion testing

[0036] The use density is 8.8g / cm 3 The 936 bronze sample was subjected to corrosion testing at 20°C. The bronze sample was cut into a diameter of 1.27 cm and a thickness of 0.32 cm. The test was carried out in a glove box, and the reagents were degassed and dried if necessary and then placed in the glove box. All experiments were repeated 5 times and the average value was recorded. The pre-measured sample was added to a 40ml vial with a decompression cap. The reagent was then added to the vial and the decompression cap was fixed. The vial was then taken out of the glove box and a photo of the vial was taken. The vial was then placed in a heating block and heated at 100°C for 2 weeks. After 2 weeks, the vial was removed from the heating block and allowed to cool. When the vial had cooled to room temperature, tweezers were used to remove the sample from the vial and place it on a chemical wipe. The sample was rinsed on a metal pan with tetradecane and completely wiped off with a metal scraper. The flat end of the scraper was used at an angle of about 30° to scrape off any corrosion or accumulation on the surface of the sample. Be careful not to apply maximum pressure to the sample during scraping to avoid scratching the surface of the sample. Rinse the sample with clean tetradecane and wipe the sample with a chemical wipe. Place each of the cleaned samples in a separate 20 ml vial. Place the vials containing the cleaned samples in a vacuum oven at 160°C overnight to dry. Then weigh the dried sample. Measure and record the difference between the dried sample weight and the starting sample weight.

[0037] Corrosion rate

[0038] The corrosion rate was measured using the following formula: where weight loss is the difference between the dry sample weight and the starting sample weight, and the alloy density is 8.8 g / cm 3 , the exposed area of ​​the specimen is measured by treating the specimen as a cylinder and the exposed area is calculated as the exposed area of ​​the cylinder. 2 The exposure area is 1.27 cm, the specimen has a diameter of 0.32 cm and a thickness of 336 hours, the exposure time is 336 hours, and K is the K factor. The alloy density and K factor values ​​were collected from the literature.

[0039]

[0040] Corrosion Inhibition

[0041] Corrosion inhibition was measured to calculate the percent corrosion inhibition using the following formula: Uninhibited corrosion rate was calculated from the corrosion rate of the sample without the inhibitor present. Inhibited corrosion rate was calculated from the corrosion rate of the sample with the inhibitor added.

[0042]

[0043] Example

[0044] The embodiments will be further illustrated by the following examples.

[0045] Table 1 - Materials added for corrosion inhibition testing

[0046] Experiment number experiment Hydrobrite 380, g Methanol, g Methacrylic acid, g Inhibitor, g A No inhibitors 7.2 0.8 4.8 0 2 Inhibitor: 2.5% DTPA 7.02 0.8 4.8 0.18 3 Inhibitor: 5% DTPA 6.84 0.8 4.8 0.36 4 Inhibitor: 10% DTPA 6.48 0.8 4.8 0.72 B Inhibitor: 5% EDTA 6.84 0.8 4.8 0.36

[0047] Table 1 shows the composition of the lubricant composition tested for its corrosion inhibition performance. Corrosion inhibitor testing was performed using a formulation with lubricating oil, methanol, methacrylic acid and an optional corrosion inhibitor. The lubricating oil used was Hydrobrite 380, a common white mineral oil produced by Sonneborn. The inhibitors used were diethylenetriaminepentaacetic acid (DTPA) and ethylenediaminetetraacetic acid (EDTA). The amount of inhibitor added in each experiment was calculated as the weight percent of the Hydrobrite 380 lubricating oil.

[0048] Table 2 - Corrosion test results

[0049]

[0050] Table 3 - Corrosion Inhibition Percent Results

[0051] Experiment number experiment Corrosion rate mil / year (mpy) Corrosion inhibition % A No inhibitors 12.25 0 2 Inhibitor: 2.5% DTPA 1.97 83.9 3 Inhibitor: 5% DTPA 1.32 89.2 4 Inhibitor: 10% DTPA 1.42 88.4 B Inhibitor: 5% EDTA 12.2 0.5

[0052] Referring to the corrosion inhibition test results in Tables 2 and 3, the experiments utilizing DTPA (i.e., Experiments 2 to 4) have significantly greater corrosion inhibition and significantly less weight loss due to corrosion than the comparative examples (such as Comparative Examples A and B) that do not utilize DTPA. In short, Tables 2 and 3 show that DTPA exhibits excellent corrosion inhibition against methanol and methacrylic acid when combined with lubricating oil. Without being limited by theory, the DTPA structure imparts improved hydrophobicity compared to EDTA, which is believed to be partially related to the improved corrosion resistance.

[0053] In a first aspect of the present disclosure, a lubricant composition may include an oil lubricant and a corrosion inhibitor, wherein the corrosion inhibitor is diethylenetriaminepentaacetic acid.

[0054] A second aspect of the present disclosure may include the first aspect, wherein the oil lubricant comprises mineral oil.

[0055] A third aspect of the disclosure may include any of the preceding aspects, wherein the lubricant composition comprises 0.5 wt % to 20 wt % of the corrosion inhibitor or 2.5 wt % to 10 wt % of the corrosion inhibitor.

[0056] A fourth aspect of the present disclosure may include a method for reducing corrosion, the method comprising exposing a metal component to a solution comprising the lubricant composition according to any of the previous aspects and (meth)acrylic acid, wherein the lubricant composition reduces metal corrosion.

[0057] A fifth aspect of the present disclosure may include the fourth aspect, wherein the solution can include a co-solvent.

[0058] A sixth aspect of the present disclosure may include the fifth aspect, wherein the co-solvent comprises a carboxylic acid, an alcohol, or a combination thereof.

[0059] A seventh aspect of the present disclosure may include the sixth aspect, wherein the alcohol comprises methanol.

[0060] An eighth aspect of the present disclosure may include the fourth to seventh aspects, wherein the metal component includes a bronze packing ring.

[0061] A ninth aspect of the present disclosure may include the eighth aspect, wherein the bronze packing ring is part of a compressor.

[0062] A tenth aspect of the present disclosure may include the eighth aspect, wherein the bronze packing ring is part of a compressor unit used in a high pressure polyethylene reactor.

[0063] An eleventh aspect of the present disclosure may include a free radicalization method comprising polymerizing ethylene monomer and optional (meth)acrylic acid comonomer via free radical polymerization in a high pressure polyethylene reactor having a compressor with bronze packing rings in the presence of the lubricant composition according to any one of the first to third aspects.

[0064] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to cover modifications and variations of the various embodiments described herein, provided that these modifications and variations fall within the scope of the appended claims and their equivalents.

[0065] For the purpose of defining the present invention, the transition phrase "consisting of" may be introduced in the claims as a closed preamble term that limits the scope of the claim to the listed components or steps and any naturally occurring impurities. For the purpose of defining the present invention, the transition phrase "consisting essentially of" may be introduced in the claims to limit the scope of one or more claim items to the stated elements, components, materials or method steps and any non-stated elements, components, materials or method steps that do not substantially affect the novel characteristics of the claimed subject matter. The transition phrases "consisting of" and "consisting essentially of" may be interpreted as open transition phrases, such as a subset of "comprising" and "including", so that any use of open phrases used to introduce a statement of a series of elements, components, materials or steps should be interpreted as also disclosing the statement of the series of elements, components, materials or steps using the closed terms "consisting of" and "consisting essentially of". For example, a statement of a composition "comprising" components A, B and C should be interpreted as also disclosing a composition "consisting of" components A, B and C and a composition "consisting essentially of" components A, B and C. Any quantitative values ​​expressed in this application may be deemed to include open embodiments conforming to the transitional phrases "comprising" or "including" as well as closed or partially closed embodiments conforming to the transitional phrases "consisting of" and "consisting essentially of.

[0066] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless the context clearly indicates otherwise. The verb "comprise" and its cognate forms should be interpreted as referring to elements, components, or steps in a non-exclusive manner. The referenced elements, components, or steps may exist, be utilized, or be combined with other elements, components, or steps that are not explicitly referenced.

[0067] It should be understood that any two quantitative values ​​assigned to a characteristic may constitute a range for that characteristic, and all combinations of ranges formed by all said quantitative values ​​of a given characteristic are considered in the present disclosure. The subject matter described herein has been described in detail and by reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily imply that the component or feature is necessary for a specific embodiment or any other embodiment. Further, it will be apparent to those skilled in the art that various modifications and changes may be made to the described embodiments without departing from the essence and scope of the claimed subject matter.

Claims

1. A lubricant composition, comprising: Oil lubricants and The corrosion inhibitor is diethylenetriaminepentaacetic acid (DTPA).

2. The lubricant composition of claim 1, wherein the oil lubricant comprises mineral oil.

3. A lubricant composition according to any preceding claim, wherein the lubricant composition comprises 0.5 wt% to 20 wt% corrosion inhibitor or 2.5 wt% to 10 wt% corrosion inhibitor.

4. A method for reducing corrosion, the method comprising: Exposing a metal component to a solution comprising a lubricant composition according to any preceding claim and (meth)acrylic acid, wherein the lubricant composition reduces metal corrosion.

5. The method of claim 4, wherein the solution may contain a co-solvent. The method of claim 5 , wherein the co-solvent comprises a carboxylic acid, an alcohol, or a combination thereof.

7. The method of claim 6, wherein the alcohol comprises methanol.

8. A method according to any one of claims 4 to 7, wherein the metal component comprises a bronze packing ring.

9. The method of claim 8, wherein the bronze packing rings are part of a compressor.

10. The method of claim 8, wherein the bronze packing rings are part of a compressor unit used in a high pressure polyethylene reactor.

11. A free radical polymerization method, comprising: Ethylene monomer and optional (meth)acrylic acid comonomer are polymerized via free radical polymerization in a high pressure polyethylene reactor having a compressor with bronze packing rings in the presence of a lubricant composition according to any one of claims 1 to 3.

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