A multi-functional biobased and biodegradable Anti-corrosion composition
Patent Information
- Application Number
- PCT/IN2026/050684
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-04-15
- Filing Date
- 2026-04-15
- Publication Date
- 2026-10-22
Smart Images
Figure IN2026050684_22102026_PF_FP_ABST
Abstract
Description
[0001] Title: A MULTI-FUNCTIONAL BIOBASED AND BIODEGRADABLE ANTICORROSION COMPOSITION FIELD OF INVENTION
[0002] The present disclosure relates to corrosion control technology for industrial water-based systems, and more particularly to a biobased, biodegradable, multi-functional anti-corrosion composition that integrates anodic and cathodic inhibition, surface passivation, and pH regulation into a single formulation.
[0003] BACKGROUND OF THE INVENTION
[0004] Corrosion in water-based systems represents a persistent challenge across numerous industrial sectors, including power generation, oil and gas, manufacturing, and water treatment. When corrosion occurs in such systems, it leads to material degradation, shortened equipment lifespan, increased maintenance and replacement costs, extended downtime, and reduced operational efficiency. In some instances, corrosion can also lead to safety hazards, leaks, and system failures.
[0005] Conventionally, corrosion control in industrial water-based systems relies on phosphate-based and polyacrylate-based inhibitors. However, phosphate-based inhibitors can contribute to environmental pollution, particularly through the promotion of eutrophication, where excess nutrients in water lead to harmful algal blooms that disrupt ecosystems and harm aquatic life. Polyacrylate-based inhibitors similarly raise environmental concerns due to their synthetic, non-biodegradable nature, which can result in long-term environmental accumulation. There exists a need for corrosion control compositions that address environmental sustainability while maintaining effective corrosion inhibition.
[0006] Conventionally, many corrosion control products are designed to work through a single mechanism of action, such as either anodic or cathodic inhibition. However, this singlemechanism focus often necessitates the use of multiple products in combination, which increases operational complexity and treatment costs. There exists a need for corrosion control compositions capable of providing multi-mode protective action within a single formulation. Conventionally, corrosion control treatments may contribute to secondary issues such as biofouling and scaling, which further complicate the treatment process and may require additional chemical interventions. However, these secondary issues add to the overall chemical load in the system and increase operational burden. There exists a need for corrosion control compositions that minimize or eliminate such secondary complications.
[0007] Conventionally, pH levels in water systems play a role in corrosion and scaling processes, and improper pH control can accelerate corrosion or promote scale formation. However,maintaining proper pH often requires the use of external pH adjustment agents, which adds to the chemical complexity of the treatment regimen. There exists a need for corrosion control compositions that incorporate pH stabilization functionality.
[0008] OBJECTS OF THE INVENTION
[0009] It is an object of the present invention to provide a biobased, biodegradable anti -corrosion composition for water-based industrial systems that eliminates the environmental concerns associated with phosphate-based and polyacrylate-based inhibitors.
[0010] It is another object of the present invention to provide an anti-corrosion composition that integrates multiple corrosion control mechanisms, including anodic inhibition, cathodic inhibition, surface passivation, and pH regulation, into a single formulation.
[0011] It is another object of the present invention to provide an anti-corrosion composition that reduces the need for multiple chemical additives, thereby decreasing chemical footprint and overall treatment costs.
[0012] It is another object of the present invention to provide a method of preparation of a biobased, biodegradable anti-corrosion composition that achieves ingredient compatibility and stability at optimum concentrations.
[0013] It is another object of the present invention to provide an anti-corrosion composition with inherent pH buffering capacity that maintains pH homeostasis within water systems without requiring external pH adjustment agents.
[0014] It is another object of the present invention to provide an anti -corrosion composition exhibiting synergistic iron-binding capacity exceeding the additive contribution of individual components.
[0015] It is another object of the present invention to provide an anti-corrosion composition that prevents scale formation by chelating scale-forming ions including calcium and magnesium. It is another object of the present invention to provide an anti -corrosion composition effective at low concentrations between 0.05% and 0.5% for corrosion suppression in water-based coating systems.
[0016] SUMMARY OF THE INVENTION
[0017] In accordance with the present invention, there is provided a biobased, biodegradable, multifunctional anti-corrosion composition for water-based industrial systems comprising a synergistic blend of non-ionic surfactants, a phosphonate chelating agent, organic acids, and an organic ester in an aqueous medium. The invention achieves comprehensive corrosion protection by integrating multiple corrosion control mechanisms including anodic passivation, cathodic inhibition, surface passivation, and pH buffering into a single formulation, therebyeliminating the need for multiple chemical additives while providing an environmentally sustainable alternative to conventional phosphate-based and polyacrylate-based inhibitors. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 illustrates a schematic representation of a multi-functional anti-corrosion composition, according to aspects of the present disclosure.
[0019] Figure 2 illustrates a process flow diagram for preparation of an anti-corrosion composition, according to an embodiment.
[0020] Figure 3 illustrates corrosion inhibition performance data of an anti-corrosion composition, according to aspects of the present disclosure.
[0021] Figure 4 illustrates pH buffering capacity of an anti-corrosion composition over time, according to an embodiment.
[0022] Figure 5 illustrates a graph % Biodegradability profile of antiscalant formulation as per OECD 301D
[0023] DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring to FIG. 1, a biobased, biodegradable, multi-functional anti-corrosion composition for water-based industrial systems may comprise a synergistic blend of components in an aqueous medium. The anti -corrosion composition may comprise polysorbate 20 as a first nonionic surfactant, polysorbate 80 as a second non-ionic surfactant, etidronic acid as a phosphonate chelating agent, lactic acid as a first organic acid, acetic acid as a second organic acid, ethyl lactate as an organic ester, and deionized water as an aqueous medium. In some cases, the anti-corrosion composition is free of phosphates and polyacrylates.
[0025] With continued reference to FIG. 1, the anti-corrosion composition may integrate multiple corrosion control mechanisms within a single formulation. The corrosion control mechanisms may include anodic passivation, cathodic inhibition, surface passivation, and pH buffering. In some cases, the integration of multiple corrosion control mechanisms within a single formulation eliminates the need for multiple chemical additives in water-based industrial systems.
[0026] The anti-corrosion composition may provide anodic passivation through formation of protective films on metal surfaces. In some cases, the protective films formed by the anticorrosion composition prevent oxidation at anodic sites on the metal surface. The anodic passivation mechanism may involve adsorption of components from the anti-corrosion composition onto the metal surface, creating a barrier that reduces the availability of anodic sites for oxidation reactions.The anti-corrosion composition may provide cathodic inhibition through reduction of oxygen diffusion at metal surfaces. In some cases, the reduction of oxygen diffusion by the anticorrosion composition minimizes localized corrosion sites on metal surfaces exposed to waterbased systems. The anti-corrosion composition may reduce the diffusion of oxygen to cathodic sites by forming a protective barrier that limits oxygen transport from the bulk aqueous environment to the metal surface.
[0027] As further shown in FIG. 1, the anti-corrosion composition may provide surface passivation through adsorption of components onto metal surfaces. In some cases, the adsorption of components onto metal surfaces forms a protective barrier that reduces interaction between the metal and corrosion-inducing agents. The corrosion-inducing agents from which the anticorrosion composition may protect metal surfaces include oxygen, chloride ions, and moisture. The anti-corrosion composition may provide pH buffering within a functional pH range of 3.0 to 4.0. In some cases, the pH buffering capacity of the anti-corrosion composition maintains pH homeostasis within water systems without requiring external pH adjustment agents. The pH buffering function may counteract pH fluctuations caused by external factors or electrochemical reactions occurring in water-based systems. In some cases, the anti-corrosion composition neutralizes excess alkalinity in water-based systems that would otherwise lead to deposition of scale on metal surfaces.
[0028] The anti-corrosion composition may comprise polysorbate 20 as a first non-ionic surfactant component. Polysorbate 20, also known as Tween 20, may act as a cathodic-type inhibitor within the anti-corrosion composition. In some cases, polysorbate 20 forms protective films on metal surfaces exposed to water-based industrial systems. Protective films formed by polysorbate 20 may reduce corrosion rates by limiting cathodic reactions that occur during corrosion processes. Polysorbate 20 may form self-assembling monolayers on carbon steel surfaces. The self-assembling monolayers formed by polysorbate 20 on carbon steel surfaces may reduce corrosion rates by creating a barrier between the metal surface and corrosive agents present in the aqueous environment. In some cases, the self-assembling monolayers promote uniform adsorption of inhibitor molecules across the metal surface, thereby enhancing the protective effect of the anti -corrosion composition.
[0029] With continued reference to FIG. 1, the anti -corrosion composition may comprise polysorbate 80 as a second non-ionic surfactant component. Polysorbate 80, also known as Tween 80, may exhibit mixed-type inhibition behavior within the anti -corrosion composition. The mixed-type inhibition behavior of polysorbate 80 indicates that polysorbate 80 may affect both anodic and cathodic corrosion reactions. In some cases, polysorbate 80 improves dispersion of activecomponents on metal surfaces through adsorption mechanisms. Polysorbate 80 may also improve adherence of active components on metal surfaces. The adsorption of polysorbate 80 onto metal surfaces may facilitate uniform distribution of other active components in the anticorrosion composition, thereby enhancing the overall protective effect of the formulation on metal substrates in water-based systems.
[0030] The polysorbate surfactants may improve dispersion properties of iron particles in water-based systems. In some cases, polysorbate 20 and polysorbate 80 enhance acid-metal interaction within the anti-corrosion composition. The polysorbate surfactants may increase dispersion ability of colloidal particles present in the system. The increased dispersion ability of colloidal particles may result in reduced particle size of iron-containing species. In some cases, the reduced particle size results in increased surface area available for interaction with chelating components of the anti-corrosion composition. The increased surface area may enhance the rate of chelation by improving contact between chelator functionality and iron particles. The improved dispersion properties provided by the polysorbate surfactants may contribute to the synergistic performance of the anti-corrosion composition by facilitating more effective interaction between the various active components and metal surfaces or metal ions present in water-based industrial systems.
[0031] The anti-corrosion composition may comprise etidronic acid as a phosphonate chelating agent. Etidronic acid may form stable chelate complexes with free metal ions present in water-based systems. In some cases, the stable chelate complexes formed by etidronic acid sequester metal ions that would otherwise catalyze corrosion processes. The chelating properties of etidronic acid may reduce the availability of metal ions for participation in oxidation reactions at metal surfaces.
[0032] With continued reference to FIG. 1, etidronic acid may prevent scale formation in water-based industrial systems. In some cases, etidronic acid binds with scale-forming ions including calcium ions and magnesium ions before the scale-forming ions precipitate onto metal surfaces. The prevention of scale formation by etidronic acid may reduce the accumulation of deposits that can create localized corrosion sites beneath scale layers. Scale deposits may form when alkaline conditions promote precipitation of calcium carbonate, magnesium hydroxide, or other mineral compounds onto metal surfaces. The scale deposits may create localized environments beneath the scale layer where corrosion can proceed at accelerated rates due to differential aeration or concentration cells.
[0033] The scale inhibition function of etidronic acid may complement the corrosion inhibition function of etidronic acid within the anti-corrosion composition. In some cases, etidronic acidcontributes to anodic passivation by forming stable chelates with metal ions, thereby reducing the availability of metal ions for oxidation at anodic areas on the metal surface. The dual functionality of etidronic acid as both a chelating agent and a scale-inhibiting agent may provide coordinated protection against both corrosion initiation and scale-related corrosion acceleration in water-based industrial systems.
[0034] The anti-corrosion composition may comprise lactic acid as a first organic acid component. Lactic acid may function as a pH buffering agent within the anti -corrosion composition. In some cases, lactic acid maintains system acidity within ranges that prevent corrosion acceleration. The pH buffering capacity of lactic acid may counteract pH fluctuations caused by external factors or electrochemical reactions occurring in water-based systems. Lactic acid may also act as an electron scavenger within the anti-corrosion composition. In some cases, lactic acid inhibits the active electron cycle responsible for metal surface oxidation. The electron scavenging function of lactic acid may interrupt electrochemical reactions that drive corrosion at metal surfaces.
[0035] With continued reference to FIG. 1, lactic acid may form soluble complexes with metal ions present in water-based systems. In some cases, the formation of soluble complexes by lactic acid reduces the availability of free metal ions that participate in corrosion processes. The complexation of metal ions by lactic acid may sequester metal ions that would otherwise catalyze further corrosion reactions or re-deposit onto metal surfaces. The reduction in free metal ion availability through complexation by lactic acid may extend the time before corrosion formation occurs in water-based industrial systems.
[0036] The anti-corrosion composition may comprise acetic acid as a second organic acid component. Acetic acid may function as a pH buffer within the anti -corrosion composition. In some cases, acetic acid aids in stabilization of system pH levels in water-based systems. The pH buffering function of acetic acid may complement the pH buffering function of lactic acid within the anti-corrosion composition. Acetic acid may maintain a slightly acidic environment in the water-based system. In some cases, the slightly acidic environment maintained by acetic acid helps minimize the corrosion potential for certain metal surfaces exposed to the aqueous environment.
[0037] As further shown in FIG. 1, the anti-corrosion composition may neutralize excess alkalinity in water-based systems. In some cases, excess alkalinity in water-based systems leads to deposition of scale on metal surfaces. Scale deposits may form when alkaline conditions promote precipitation of calcium carbonate, magnesium hydroxide, or other mineral compounds onto metal surfaces. The scale deposits may create localized environments beneaththe scale layer where corrosion can proceed at accelerated rates due to differential aeration or concentration cells. The anti-corrosion composition may neutralize excess alkalinity through the acidic components of the formulation, including lactic acid and acetic acid, which react with hydroxide ions to reduce the alkalinity of the water-based system.
[0038] The anti-corrosion composition may comprise ethyl lactate as an organic ester component. Ethyl lactate may adsorb onto metal surfaces through interactions between the ester functional group (-COOR) and metal ions present at the metal surface. In some cases, the adsorption of ethyl lactate onto metal surfaces forms a protective barrier that reduces interaction between the metal and corrosion-inducing agents. The corrosion-inducing agents from which ethyl lactate may protect metal surfaces include oxygen, chloride ions, and moisture. The protective barrier formed by ethyl lactate may slow down oxidation reactions at the metal surface by limiting access of corrosive species to the underlying metal substrate.
[0039] With continued reference to FIG. 1, ethyl lactate may promote formation of an oxide layer on metal surfaces. In some cases, the oxide layer formed through the action of ethyl lactate enhances passivation of the metal surface. The passivation of the metal surface by the oxide layer may prevent metal dissolution by creating a stable barrier between the underlying metal substrate and the aqueous environment. The oxide layer promoted by ethyl lactate may protect against further electrochemical reactions that would otherwise lead to corrosion of the metal surface. In some cases, the passivation enhancement provided by ethyl lactate contributes to the overall corrosion inhibition mechanism of the anti-corrosion composition in water-based industrial systems.
[0040] Ethyl lactate may undergo controlled hydrolysis within the anti -corrosion composition. In some cases, the controlled hydrolysis of ethyl lactate releases lactate ions into the aqueous environment. The lactate ions released through hydrolysis of ethyl lactate may complex with free metal ions present in the water-based system. The complexation of free metal ions by lactate ions may reduce the concentration of free metal ions available to participate in corrosion reactions or to catalyze further corrosion processes. In some cases, the complexation of free metal ions by lactate ions stabilizes the electrochemical environment by reducing variability in metal ion concentration across the metal surface. The stabilization of the electrochemical environment through complexation of free metal ions by lactate ions may contribute to the prevention of differential corrosion effects in water-based industrial systems.
[0041] The anti-corrosion composition may comprise components present within specified concentration ranges. In some cases, polysorbate 20 is present in an amount of 1 wt% to 15 wt% of the total composition. In some cases, polysorbate 80 is present in an amount of 1 wt%to 20 wt% of the total composition. The concentration ranges of polysorbate 20 and polysorbate 80 may provide sufficient surfactant content to form protective films on metal surfaces and to improve dispersion properties of iron particles in water-based systems.
[0042] With continued reference to FIG. 1, etidronic acid may be present in an amount of 0.5 wt% to 10 wt% of the total composition. The concentration range of etidronic acid may provide sufficient chelating capacity to sequester free metal ions and to prevent scale formation by binding with scale-forming ions including calcium ions and magnesium ions.
[0043] The anti-corrosion composition may comprise lactic acid present in an amount of 5 wt% to 30 wt% of the total composition. In some cases, acetic acid is present in an amount of 2 wt% to 15 wt% of the total composition. The concentration ranges of lactic acid and acetic acid may provide pH buffering capacity within the functional pH range of 3.0 to 4.0. The organic acid components at the specified concentration ranges may also contribute to electron scavenging and metal ion complexation functions within the anti-corrosion composition.
[0044] As further shown in FIG. 1, ethyl lactate may be present in an amount of 1 wt% to 15 wt% of the total composition. The concentration range of ethyl lactate may provide sufficient organic ester content to form protective barriers on metal surfaces through adsorption mechanisms and to promote formation of oxide layers that enhance passivation of metal surfaces.
[0045] The anti-corrosion composition may comprise deionized water as an aqueous medium constituting the balance to 100 wt% of the total composition. In some cases, the deionized water serves as a carrier medium for the active components of the anti -corrosion composition. The aqueous medium may facilitate uniform distribution of the active components throughout the anti-corrosion composition and may enable application of the anti-corrosion composition to water-based industrial systems.
[0046] Referring to FIG. 2, the anti-corrosion composition may be prepared according to a method comprising a series of mixing and addition steps. In some cases, the preparation method begins by mixing polysorbate 20 and polysorbate 80 in a suitable vessel. The mixing of polysorbate 20 and polysorbate 80 may be performed under continuous stirring. In some cases, the continuous stirring is performed at ambient temperature within a temperature range of 20°C to 35°C. The mixing of polysorbate 20 and polysorbate 80 under continuous stirring at a stirring speed of 100 rpm to 500 rpm may form a homogeneous surfactant blend. In some cases, polysorbate 20 is present in an amount of 1 wt% to 15 wt% and polysorbate 80 is present in an amount of 1 wt% to 20 wt% of the total composition. The homogeneous surfactant blend may serve as a base for the subsequent addition of other components of the anti-corrosion composition.With continued reference to FIG. 2, the continuous stirring during the mixing of polysorbate 20 and polysorbate 80 may ensure uniform distribution of the non-ionic surfactant components throughout the surfactant blend. In some cases, the stirring speed within the range of 100 rpm to 500 rpm provides sufficient agitation to achieve homogeneity without introducing excessive shear forces that could affect the surfactant properties. The ambient temperature range of 20°C to 35°C may maintain the polysorbate surfactants in a liquid state suitable for mixing while avoiding thermal degradation of the surfactant components.
[0047] With continued reference to FIG. 2, following formation of the homogeneous surfactant blend, etidronic acid may be added to the surfactant blend. In some cases, etidronic acid is gradually added to the surfactant blend. The gradual addition of etidronic acid may be performed with continued agitation at a stirring speed of 150 rpm to 600 rpm to ensure complete dissolution of etidronic acid within the surfactant blend. In some cases, etidronic acid is present in an amount of 0.5 wt% to 10 wt% of the total composition.
[0048] The complete dissolution of etidronic acid may facilitate uniform distribution of etidronic acid throughout the mixture. In some cases, the uniform distribution of etidronic acid allows etidronic acid to contribute to the chelating and corrosion inhibition functions of the anticorrosion composition. The continued agitation during the addition of etidronic acid may prevent localized concentration gradients that could affect the homogeneity of the mixture. In some cases, the stirring speed within the range of 150 rpm to 600 rpm provides sufficient agitation to achieve dissolution of etidronic acid while maintaining the integrity of the surfactant blend formed in the preceding step.
[0049] With continued reference to FIG. 2, ethyl lactate may be incorporated into the mixture following the addition of etidronic acid. In some cases, ethyl lactate is incorporated under controlled stirring conditions at a stirring speed of 100 rpm to 400 rpm. The controlled stirring conditions may be maintained for a duration of 10 minutes to 30 minutes to form a consistent mixture. In some cases, ethyl lactate is present in an amount of 1 wt% to 15 wt% of the total composition.
[0050] The incorporation of ethyl lactate under controlled stirring conditions may ensure that ethyl lactate is uniformly distributed throughout the mixture containing the surfactant blend and etidronic acid. In some cases, the stirring speed within the range of 100 rpm to 400 rpm provides sufficient agitation to achieve uniform distribution of ethyl lactate without introducing excessive shear forces that could affect the properties of the mixture components. The duration of 10 minutes to 30 minutes may allow sufficient time for ethyl lactate to disperse throughout the mixture and to interact with the surfactant blend and etidronic acid present in the mixture.As further shown in FIG. 2, the uniform distribution of ethyl lactate throughout the mixture may facilitate the contribution of ethyl lactate to the corrosion inhibition functions of the anticorrosion composition. In some cases, the consistent mixture formed through the controlled incorporation of ethyl lactate provides a stable base for the subsequent introduction of organic acid components. The controlled stirring conditions during ethyl lactate incorporation may prevent localized concentration gradients that could affect the homogeneity of the anticorrosion composition.
[0051] With continued reference to FIG. 2, lactic acid and acetic acid may be introduced into the mixture following the incorporation of ethyl lactate. In some cases, lactic acid and acetic acid are sequentially introduced into the mixture. The sequential introduction may involve first adding lactic acid to the mixture, followed by the addition of acetic acid. In some cases, lactic acid is present in an amount of 5 wt% to 30 wt% of the total composition. In some cases, acetic acid is present in an amount of 2 wt% to 15 wt% of the total composition.
[0052] The sequential introduction of lactic acid and acetic acid may be performed while maintaining uniform mixing at a stirring speed of 150 rpm to 500 rpm. The uniform mixing during the introduction of lactic acid and acetic acid may achieve a homogeneous mixture in which lactic acid and acetic acid are evenly distributed throughout the composition. In some cases, the stirring speed within the range of 150 rpm to 500 rpm provides sufficient agitation to achieve uniform distribution of the organic acid components without introducing excessive shear forces that could affect the properties of the mixture components.
[0053] As further shown in FIG. 2, the homogeneous distribution of lactic acid and acetic acid may allow the organic acid components to provide pH buffering and corrosion inhibition functions throughout the anti-corrosion composition. In some cases, the uniform distribution of lactic acid enables lactic acid to contribute to pH buffering, electron scavenging, and metal ion complexation functions throughout the anti -corrosion composition. The uniform distribution of acetic acid may enable acetic acid to complement the pH buffering function of lactic acid and to aid in stabilization of system pH levels in water-based systems.
[0054] The mixture may be diluted with deionized water following the introduction of lactic acid and acetic acid. In some cases, the mixture is diluted with deionized water to a desired volume. The deionized water may constitute the balance to 100 wt% of the total composition. The dilution with deionized water to the desired volume may yield the final composition of the anticorrosion composition.
[0055] With continued reference to FIG. 2, the dilution may be carried out under stirring conditions of 50 rpm to 300 rpm for a duration of 10 minutes to 20 minutes to ensure uniformity. In somecases, the stirring speed within the range of 50 rpm to 300 rpm provides gentle agitation sufficient to achieve uniform distribution of the deionized water throughout the mixture without disrupting the homogeneity of the previously combined components. The duration of 10 minutes to 20 minutes may allow sufficient time for the deionized water to disperse throughout the mixture and to achieve a uniform final composition.
[0056] The use of deionized water for dilution may reduce the introduction of mineral ions or other contaminants that could interfere with the corrosion inhibition functions of the anti-corrosion composition. In some cases, the use of deionized water prevents the introduction of calcium ions, magnesium ions, or other scale-forming ions that could reduce the effectiveness of the chelating components of the anti-corrosion composition. The final composition obtained through dilution with deionized water may integrate anodic passivation, cathodic inhibition, surface passivation, and pH buffering functions within a single formulation.
[0057] Referring to FIG. 3, the anti -corrosion composition may provide corrosion protection through multiple mechanisms operating in coordination. The corrosion protection mechanisms may include anodic passivation, cathodic inhibition, and electrochemical stabilization. In some cases, the coordination of multiple corrosion protection mechanisms within a single formulation provides comprehensive protection against corrosion at metal surfaces exposed to water-based industrial systems.
[0058] The anti-corrosion composition may provide anodic passivation through formation of protective films on metal surfaces. In some cases, the protective films formed by the anticorrosion composition prevent oxidation at anodic sites on the metal surface. The anodic passivation mechanism may involve adsorption of components from the anti-corrosion composition onto the metal surface, creating a barrier that reduces the availability of anodic sites for oxidation reactions. The protective films may inhibit metal dissolution by blocking the transfer of metal ions from the metal substrate into the aqueous environment. In some cases, the anodic passivation provided by the anti -corrosion composition reduces the rate of corrosion initiation at metal surfaces exposed to water-based industrial systems.
[0059] With continued reference to FIG. 3, etidronic acid within the anti -corrosion composition may contribute to anodic passivation by forming stable chelates with metal ions. In some cases, the formation of stable chelates by etidronic acid reduces the availability of metal ions for oxidation at anodic areas on the metal surface. The chelation of metal ions by etidronic acid may sequester metal ions that would otherwise participate in oxidation reactions, thereby reducing the driving force for anodic dissolution of the metal substrate.The anti-corrosion composition may provide cathodic inhibition through reduction of oxygen diffusion at metal surfaces. In some cases, the reduction of oxygen diffusion by the anticorrosion composition minimizes localized corrosion sites on metal surfaces exposed to waterbased systems. Cathodic corrosion reactions involve the reduction of oxygen at cathodic sites on the metal surface, and the rate of cathodic reactions may be limited by the availability of oxygen at cathodic sites. The anti-corrosion composition may reduce the diffusion of oxygen to cathodic sites by forming a protective barrier that limits oxygen transport from the bulk aqueous environment to the metal surface. In some cases, the reduction of oxygen diffusion by the anti-corrosion composition decreases the rate of cathodic oxygen reduction reactions, thereby reducing the overall corrosion rate at metal surfaces.
[0060] As further shown in FIG. 3, the minimization of localized corrosion sites through cathodic inhibition may prevent the development of pitting corrosion and other forms of localized attack. In some cases, localized corrosion occurs when cathodic reactions are concentrated at specific sites on the metal surface where oxygen availability is higher than at surrounding areas. The anti-corrosion composition may reduce the concentration of cathodic reactions at specific sites by limiting oxygen diffusion uniformly across the metal surface. The uniform limitation of oxygen diffusion may distribute cathodic activity more evenly across the metal surface, reducing the formation of localized corrosion sites that would otherwise lead to accelerated material degradation.
[0061] Polysorbate 20 within the anti -corrosion composition may act as a cathodic-type inhibitor. In some cases, polysorbate 20 forms protective films on metal surfaces exposed to water-based industrial systems. Protective films formed by polysorbate 20 may reduce corrosion rates by limiting cathodic reactions that occur during corrosion processes. Polysorbate 20 may form self-assembling monolayers on carbon steel surfaces. The self-assembling monolayers formed by polysorbate 20 on carbon steel surfaces may reduce corrosion rates by creating a barrier between the metal surface and corrosive agents present in the aqueous environment. In some cases, the self-assembling monolayers promote uniform adsorption of inhibitor molecules across the metal surface, thereby enhancing the protective effect of the anti-corrosion composition.
[0062] With continued reference to FIG. 3, polysorbate 80 within the anti-corrosion composition may exhibit mixed-type inhibition behavior. The mixed-type inhibition behavior of polysorbate 80 indicates that polysorbate 80 may affect both anodic and cathodic corrosion reactions. In some cases, polysorbate 80 improves dispersion of active components on metal surfaces through adsorption mechanisms. The adsorption of polysorbate 80 onto metal surfaces may facilitateuniform distribution of other active components in the anti-corrosion composition, thereby enhancing the overall protective effect of the formulation on metal substrates in water -based systems.
[0063] The anti-corrosion composition may provide electrochemical stabilization in water-based industrial systems. In some cases, the electrochemical stabilization provided by the anticorrosion composition maintains stable electrochemical conditions at metal surfaces. The maintenance of stable electrochemical conditions may prevent differential corrosion that occurs when different areas of a metal surface experience different electrochemical potential. Differential corrosion may result from variations in oxygen concentration, pH, or ionic composition across the metal surface, leading to the formation of galvanic cells that accelerate corrosion at anodic areas. The anti-corrosion composition may stabilize the electrochemical environment by reducing variations in oxygen concentration, pH, and ionic composition across the metal surface.
[0064] As further shown in FIG. 3, the prevention of differential corrosion by the anti -corrosion composition may extend the service life of metal components in water-based industrial systems. In some cases, differential corrosion leads to preferential attack at specific locations on the metal surface, resulting in localized thinning or perforation of metal components. The electrochemical stabilization provided by the anti-corrosion composition may reduce the driving force for galvanic corrosion by maintaining more uniform electrochemical conditions across the metal surface. The maintenance of uniform electrochemical conditions may reduce the potential difference between anodic and cathodic areas, thereby decreasing the rate of electron transfer and metal dissolution associated with differential corrosion.
[0065] The lactate ions released through hydrolysis of ethyl lactate may contribute to electrochemical stabilization by complexing with free metal ions and reducing variability in metal ion concentration across the metal surface. In some cases, the complexation of free metal ions by lactate ions stabilizes the electrochemical environment by reducing concentration gradients that would otherwise promote differential corrosion. The reduction in variability of metal ion concentration across the metal surface may contribute to the prevention of differential corrosion effects in water-based industrial systems.
[0066] The anti-corrosion composition may exhibit biobased properties derived from the renewable origin of the composition components. In some cases, the biobased carbon content of the anticorrosion composition is determined through a carbon mass balance approach in accordance with ISO 16620 methodology. The carbon mass balance approach may involve quantifying the total carbon content of the formulation derived from all constituent components anddetermining the fraction of carbon originating from renewable biobased sources. In some cases, each component of the anti-corrosion composition is evaluated based on weight fraction, total carbon content, and origin as either biobased or fossil-based.
[0067] The biobased carbon content of the anti -corrosion composition may be expressed as a percentage of total carbon. Table 1 presents biobased carbon analysis data for the anti-corrosion composition.
[0068] Table 1: Biobased carbon analysis of anti -corrosion composition components Component Concentration Biobased Petroleum Based Net Range Carbon Carbon Carbon Polysorbate 80 1-20% 7.7-153.6 0 7.7-153.6 Polysorbate 20 1-20% 7-139.2 0 7-139.2 Acetic acid 2-15% 1.2-9 0 1.2-9 Etidronic acid 0.5-10% 0 0.12-2.4 0.12-2.4 Ethyl lactate 1-15% 0.6-9 0 0.6-9 Lactic acid 5-30% 1.8-10.8 0 1.8-10.8
[0069]
[0070] In some cases, the anti-corrosion composition exhibits a biobased carbon content of 99% within the specified concentration ranges of the constituent components. The biobased carbon content of 99% indicates that substantially all of the carbon present in the anti-corrosion composition originates from renewable sources rather than petroleum-based sources.
[0071] The anti-corrosion composition may exhibit biodegradable properties as measured according to OECD 301 D closed bottle test methodology. The OECD 301 D test method assesses the extent of microbial degradation by measuring the consumption of dissolved oxygen in a closed system. In some cases, the anti-corrosion composition is introduced into a mineral medium inoculated with a low concentration of microorganisms, and the system is incubated under controlled conditions. As biodegradation progresses, microorganisms may utilize the anticorrosion composition as a carbon source, resulting in oxygen depletion. The degree of biodegradation may be determined by comparing the measured Biochemical Oxygen Demand (BOD) with the Theoretical Oxygen Demand (ThOD) of the anti-corrosion composition. In some cases, the anti-corrosion composition demonstrates a biodegradability of 96.70% as measured according to OECD 301 D. The biodegradation profile of the anti -corrosion composition may indicate rapid onset of biodegradation. In some cases, the anti-corrosion composition achieves 70.45% biodegradation within 1 day and 96.72% biodegradation within2 days. The rapid biodegradation profile indicates that the anti-corrosion composition is susceptible to microbial breakdown under aerobic environmental conditions.
[0072] According to OECD criteria, a substance is classified as readily biodegradable if the substance achieves at least 60% biodegradation within a specified time window during the test period. In some cases, the anti-corrosion composition is classified as readily biodegradable according to OECD criteria based on the biodegradation performance exceeding the 60% threshold. The readily biodegradable classification indicates that the anti-corrosion composition is not expected to persist in natural ecosystems following discharge or disposal.
[0073] The biobased and biodegradable properties of the anti-corrosion composition may provide an environmentally sustainable alternative to conventional phosphate-based and polyacrylate-based corrosion inhibitors. In some cases, the biobased origin of the anti -corrosion composition reduces reliance on petroleum-derived feedstocks. The biodegradable nature of the anticorrosion composition may reduce environmental accumulation concerns associated with synthetic, non-biodegradable corrosion inhibitors.
[0074] With reference to FIG. 3, electrochemical impedance spectroscopy testing was conducted in accordance with ISO 16773 guidelines on water-based anticorrosive direct-to-metal coatings containing varying concentrations of the anti-corrosion composition. The coatings comprised 54% binder and 6.5% pigment and extenders. The coatings exhibited a dry film thickness of 22-25 pm as measured according to ASTM D6132. The coatings exhibited a gloss of 85-90 units at 60° as measured according to ASTM D523. The coatings exhibited 100% adhesion as measured according to ASTM D3359. The coatings exhibited 2H pencil hardness as measured according to ASTM D3363.
[0075] With continued reference to FIG. 3, the corrosion rate on the exposed panels was measured in mils per year (MPY). Table 2 presents the corrosion rate data obtained for the 6.5% pigment system at varying concentrations of the anti-corrosion composition.
[0076] Table 2
[0077] Sample Product Concentration (%) Corrosion Rate (MPY) Blank 0 0.565
[0078] Product Concentration 1 0.05 0.067
[0079] Product Concentration 2 0.10 0.038
[0080] Product Concentration 3 0.25 0.038
[0081] Product Concentration 4 0.50 0.037
[0082]
[0083] As shown in FIG. 3, the blank coating without the anti-corrosion composition exhibited a corrosion rate of 0.565 MPY. The anti-corrosion composition at 0.05% concentration achieved a corrosion rate of 0.067 MPY in the 6.5% pigment system. The anti-corrosion composition at 0.10% concentration achieved a corrosion rate of 0.038 MPY in the 6.5% pigment system. The anti-corrosion composition at 0.25% concentration achieved a corrosion rate of 0.038 MPY in the 6.5% pigment system. The anti-corrosion composition at 0.50% concentration achieved a corrosion rate of 0.037 MPY in the 6.5% pigment system. The anti-corrosion composition reduced the corrosion rate from 0.565 MPY to 0.037 MPY at 0.50% concentration. The electrochemical impedance spectroscopy data demonstrates corrosion suppression across the concentration range of 0.05% to 0.50% of the anti -corrosion composition in the 6.5% pigment coating system.
[0084] Electrochemical impedance spectroscopy testing was also conducted on water-based anticorrosive direct-to-metal coatings containing the anti-corrosion composition at varying concentrations in a 20% pigment system. The coatings in the 20% pigment system comprised 54% binder and 20% pigment and extenders. The coatings exhibited a dry film thickness of 30-36 pm as measured according to ASTM D6132. The coatings exhibited a gloss of 60-65 units at 60° as measured according to ASTM D523. The coatings exhibited 100% adhesion as measured according to ASTM D3359. The coatings exhibited HB-F pencil hardness as measured according to ASTM D3363.
[0085] With continued reference to FIG. 3, the corrosion rate on the exposed panels in the 20% pigment system was measured in mils per year (MPY). Table 3 presents the corrosion rate data obtained for the 20% pigment system at varying concentrations of the anti-corrosion composition.
[0086] Table 3
[0087] Sample Product Concentration (%) Corrosion Rate (MPY) Blank 0 0.0327
[0088] Product Concentration 1 0.05 0.0117
[0089] Product Concentration 2 0.10 0.018
[0090] Product Concentration 3 0.25 0.015
[0091] Product Concentration 4 0.50 0.0061
[0092]
[0093] As further shown in FIG. 3, the blank coating without the anti-corrosion composition exhibited a corrosion rate of 0.0327 MPY in the 20% pigment system. The anti-corrosion composition at 0.05% concentration achieved a corrosion rate of 0.0117 MPY in the 20% pigment system.The anti-corrosion composition at 0.10% concentration achieved a corrosion rate of 0.018 MPY in the 20% pigment system. The anti-corrosion composition at 0.25% concentration achieved a corrosion rate of 0.015 MPY in the 20% pigment system. The anti -corrosion composition at 0.50% concentration achieved a corrosion rate of 0.0061 MPY in the 20% pigment system. The anti-corrosion composition reduced the corrosion rate from 0.0327 MPY to 0.0061 MPY at 0.50% concentration in the 20% pigment system.
[0094] The electrochemical impedance spectroscopy data demonstrates corrosion suppression across the concentration range of 0.05% to 0.50% of the anti-corrosion composition in the 20% pigment coating system. In some cases, the anti-corrosion composition is effective at low concentrations between 0.05% and 0.5% for corrosion suppression in water-based coating systems.
[0095] Referring to FIG. 4, the anti-corrosion composition may exhibit pH buffering capacity within a functional pH range of 3.0 to 4.0. Buffer capacity (P) may be determined by incremental titration with standardized NaOH under controlled experimental conditions. The buffer capacity may be calculated using the formula:
[0096] where An represents moles of NaOH consumed and ApH represents change in pH within the functional pH range of 3.0 to 4.0.
[0097] With continued reference to FIG. 4, buffer capacity measurements were obtained for individual raw materials and the product formulation under identical experimental conditions. Table 4 presents the measured buffer capacities for the individual components and the product formulation.
[0098] Table 4
[0099] Sample Buffer Capacity (P)
[0100] Etidronic acid (1%) 0.005
[0101] Lactic acid (1%) 0.014
[0102] Ethyl lactate (1%) 0.002
[0103] Polysorbate 20 (1%) 8.63E-05
[0104] Polysorbate 80 (1%) 0.0001
[0105] Acetic acid (1%) 0.0001
[0106] Product formulation (1%) 0.002
[0107] Theoretical additive (scaled) 0.0004
[0108]
[0109] As shown in FIG. 4, the theoretical additive buffer capacity was calculated by adjusting individual raw material buffering values according to the actual concentration of eachcomponent in the diluted product formulation. The experimentally measured buffering capacity of the product formulation at 1% concentration is 0.002. The theoretical additive buffer capacity based on proportional raw material buffering values at equivalent effective concentrations is 0.0004. The measured buffering capacity of the product formulation is approximately five-fold higher than the theoretically predicted value based on individual additive contribution calculated from proportional raw material buffering values.
[0110] The buffering behavior of the product formulation confirms synergistic performance of the ingredients used for preparing the formulation. In some cases, the enhanced buffering capacity is not inherent to any individual component, as none of the raw materials independently reproduce the observed buffering magnitude at corresponding effective concentrations. The product formulation may maintain pH buffering within the functional pH range of 3.0 to 4.0, thereby contributing to the pH homeostasis function of the anti-corrosion composition in waterbased industrial systems.
[0111] The anti-corrosion composition may exhibit synergistic iron-binding capacity when the components are combined in the product formulation. Iron (III) coordination behavior testing was conducted with all ingredients tested at the concentration used in the actual formulation. Table 5 presents the binding iron results obtained for individual ingredients and the product formulation.
[0112] Table 5
[0113] Ingredient Iron Binding (mg of Fe3+)
[0114] Lactic acid 17
[0115] Acetic acid 10
[0116] Etidronic acid 28
[0117] Polysorbate 20 10
[0118] Polysorbate 80 9
[0119] Ethyl lactate 14
[0120] Product formulation 54
[0121]
[0122] As shown in Table 4, the product formulation exhibits an iron-binding capacity of 54 mg of Fe3+under the test conditions. The iron-binding capacity of the product formulation exceeds the iron-binding capacity of any individual ingredient tested under identical conditions. Etidronic acid exhibits an iron-binding capacity of 28 mg of Fe3+. Lactic acid exhibits an iron-binding capacity of 17 mg of Fe3+. Ethyl lactate exhibits an iron-binding capacity of 14 mg of Fe3+. Acetic acid exhibits an iron-binding capacity of 10 mg of Fe3+. Polysorbate 20 exhibitsan iron-binding capacity of 10 mg of Fe3+. Polysorbate 80 exhibits an iron-binding capacity of 9 mg of Fe3+.
[0123] The enhanced iron-binding capacity of the product formulation may be attributed to synergistic effects among the components. In some cases, no individual ingredient reproduces or approaches the 54 mg of Fe3+binding capacity exhibited by the product formulation. The polysorbate surfactants may improve solubility and dispersion within the formulation. In some cases, polysorbate 20 and polysorbate 80 enhance the acid-metal interaction by improving dispersion properties of iron particles in the system. The improved dispersion may increase contact between the chelator functionality of the organic acids and iron particles, thereby enhancing the overall iron-binding capacity of the product formulation.
[0124] Neutral salt spray testing was conducted in accordance with ASTM Bl 17 standard using coated panels prepared with and without the anti-corrosion composition. A cross-cut method was followed with the test specimens for evaluating corrosion performance at 164 hours, 364 hours, and 552 hours of exposure. The neutral salt spray test was aimed at evaluating surface adsorption mediated passivation and chelation driven cathodic inhibition provided by the anticorrosion composition.
[0125] Figure 5 illustrates the biodegradability profile of the disclosed formulation, showing that the formulation undergoes rapid and substantial biodegradation under OECD 301D closed bottle test conditions, thereby evidencing its environmentally compatible character; in particular, the graph demonstrates a progressive increase in percentage biodegradability with time, reaching about 70.45% within 1 day and about 96.72% within 2 days, which is significantly above the OECD threshold for ready biodegradability, thereby indicating that the formulation is readily biodegradable and is not expected to persist in the environment after use or disposal.
[0126] Table 6 presents the corrosion characteristics observed after salt spray exposure for blank coatings and coatings containing the anti-corrosion composition at concentrations of 0.1%, 0.25%, and 0.5%.
[0127] Table 6
[0128] Assessment Blank Product Product Product Parameter Concentration 1 Concentration 2 Concentration 3
[0129] (0.1%) (0.25%) (0.5%) Corrosion 1 mm thick 1 mm thick spots 1 mm thick spots 1 mm thick spots spots in open spots approx. 30-40 in approx. 15-20 in approx. 60-80 in area approx. 50- number; fine number; fine number; fine
[0130]
[0131] 60 in pinpoint spots pinpoint spots pinpoint spots number; approx. 150-180 approx. 100-150 in approx. 150-200 in fine in number number; rust line number; rust line pinpoint present on left side on left side spots
[0132] approx.
[0133] 100-150 in
[0134] number;
[0135] rust line on
[0136] left side
[0137] Corrosion 1 mm thick 1 mm thick spots 1 mm thick spots 1 mm thick spots spots on and spots approx. 80-100 in approx. 60-80 in approx. 100-120 in near crosscut approx. number; fine number; fine number; fine 100-150 in pinpoint spots pinpoint spots pinpoint spots number; approx. 30-50 in approx. 10-20 in approx. 50-60 in fine number number number pinpoint
[0138] spots
[0139] approx. 10- 20 in
[0140] number
[0141] Spread of 5-6 mm 2-3 mm 2-3 mm 4-6 mm corrosion
[0142] alongside
[0143] crosscut
[0144]
[0145] The coating containing 0.1% of the anti-corrosion composition exhibited passing salt-spray performance up to 364 hours of exposure. Panels containing 0.1% and 0.25% of the anticorrosion composition continued to 552 hours of exposure and exhibited lower corrosion relative to the blank coating.
[0146] Table 7 presents the relative corrosion reduction observed for coatings containing the anticorrosion composition compared with the blank coating after salt spray exposure according to ASTMB117.Table 7
[0147] Assessment Parameter Observed Reduction Relative to Blank Corrosion spots in open area (~1 mm thick) Approximately 50-60% reduction Corrosion spots on and near crosscut (~1 mm Approximately 40-50% reduction
[0148] thick)
[0149] Spread of corrosion alongside crosscut Approximately 50% reduction
[0150]
[0151] The coating containing 0.25% of the anti-corrosion composition exhibited approximately 50-60% reduction in corrosion spots in open area for spots of approximately 1 mm thickness relative to the blank coating. The coating containing 0.25% of the anti -corrosion composition exhibited approximately 40-50% reduction in corrosion spots on and near the crosscut for spots of approximately 1 mm thickness relative to the blank coating. The coating containing 0.25% of the anti-corrosion composition exhibited approximately 50% reduction in spread of corrosion alongside the crosscut relative to the blank coating.
[0152] The anti-corrosion composition may provide salt spray resistance sustained to 552 hours with reduced corrosion spots and spread when tested according to ASTM Bl 17. In some cases, the salt spray resistance data supports the surface passivation, barrier formation, and cathodic inhibition mechanisms provided by the anti-corrosion composition. The reduced corrosion propagation under accelerated salt spray exposure and sustained protective film integrity relative to blank coatings may demonstrate the multi-modal corrosion inhibition mechanism of the anti-corrosion composition.
[0153] The experimental data obtained from electrochemical impedance spectroscopy testing and neutral salt spray testing may be correlated with technical effects and features of the anticorrosion composition. Table 8 presents the correlation of experimental evidence with technical effects demonstrated and supported features of the anti-corrosion composition. Table 8
[0154] Experimental Evidence Technical Effect Supported Feature Demonstrated
[0155] EIS corrosion-rate reduction Electrochemical stabilization Multi-functional at 0.05-0.5% in 6.5% and and concentration-dependent corrosion inhibition 20% pigment coatings corrosion inhibition behavior of a single formulation
[0156]
[0157] Corrosion suppression Formulation-independent Applicability across observed across different corrosion protection coating compositions pigment loading regimes
[0158] Salt spray resistance sustained Surface passivation, durable Synergistic protective to 552 hours with reduced corrosion resistance, and performance of the corrosion spots and spread reduced corrosion propagation composition Effective inhibition at low High corrosion-inhibition Multimodal nature additive concentration efficiency providing combined effects at low concentration
[0159] W
[0160]
[0161] ith continued reference to HG. 3, the electrochemical impedance spectroscopy data demonstrates corrosion-rate reduction at concentrations between 0.05% and 0.5% in both the 6.5% pigment system and the 20% pigment system. In some cases, the corrosion-rate reduction observed in the electrochemical impedance spectroscopy data supports the electrochemical stabilization mechanism of the anti-corrosion composition. The concentration-dependent corrosion inhibition observed in the electrochemical impedance spectroscopy data may support the multi-functional corrosion inhibition behavior provided by the single formulation of the anti-corrosion composition.
[0162] The corrosion suppression observed across different pigment loading regimes, including the 6.5% pigment system and the 20% pigment system, may demonstrate formulation-independent corrosion protection. In some cases, the applicability of the anti -corrosion composition across different coating compositions supports the versatility of the formulation for use in various water-based industrial systems. The formulation-independent corrosion protection may indicate that the corrosion inhibition mechanisms of the anti-corrosion composition operate independently of the specific coating matrix in which the anti -corrosion composition is incorporated.
[0163] As further shown in FIG. 3, the salt spray resistance sustained to 552 hours of exposure with reduced corrosion spots and reduced spread of corrosion may demonstrate surface passivation, durable corrosion resistance, and reduced corrosion propagation provided by the anti-corrosion composition. In some cases, the sustained protective film integrity relative to blank coatings supports the synergistic protective performance of the components within the anti -corrosion composition. The reduced corrosion propagation under accelerated salt spray exposure mayindicate that the protective films formed by the anti-corrosion composition maintain barrier function under prolonged exposure to corrosive conditions.
[0164] The effective corrosion inhibition achieved at low additive concentrations between 0.05% and 0.5% may demonstrate high corrosion-inhibition efficiency of the anti -corrosion composition. In some cases, the ability to achieve corrosion suppression at low concentrations supports the multimodal nature of the anti-corrosion composition, wherein the combined effects of anodic passivation, cathodic inhibition, surface passivation, and pH buffering are provided within a single formulation at low additive concentrations. The high corrosion-inhibition efficiency at low concentrations may reduce the overall chemical load required for corrosion protection in water-based industrial systems.
[0165] The anti-corrosion composition may be applied in water-based industrial systems across various sectors. In some cases, the anti -corrosion composition provides corrosion protection in power generation facilities, oil and gas operations, manufacturing facilities, and water treatment applications.
[0166] The anti-corrosion composition may be applied in power generation facilities where cooling water systems are subject to corrosion. Cooling water systems in power generation facilities may circulate water through heat exchangers, condensers, and cooling towers where metal surfaces are exposed to aqueous environments. The anti-corrosion composition may protect metal components within cooling water systems by providing anodic passivation, cathodic inhibition, surface passivation, and pH buffering. In some cases, the anti-corrosion composition is applied in power generation facilities where boiler systems are subject to corrosion. Boiler systems in power generation facilities may operate under elevated temperature and pressure conditions where corrosion can lead to material degradation and equipment failure. The anticorrosion composition may protect metal surfaces within boiler systems by forming protective films and maintaining electrochemical stability within the water-based environment.
[0167] The anti-corrosion composition may be applied in oil and gas operations. In some cases, the anti-corrosion composition is applied in pipelines that contact water-based fluids. Pipelines in oil and gas operations may transport fluids containing water or may be exposed to water ingress, creating conditions where corrosion can occur at internal metal surfaces. The anticorrosion composition may protect pipeline surfaces by chelating metal ions and forming protective barriers that reduce interaction between the metal and corrosion-inducing agents. In some cases, the anti-corrosion composition is applied in storage tanks that contact water-based fluids. Storage tanks in oil and gas operations may contain water bottoms or water-oil emulsions where corrosion can occur at the tank floor and lower sidewalls. The anti -corrosioncomposition may protect storage tank surfaces by providing surface passivation and pH buffering within the aqueous phase. In some cases, the anti-corrosion composition is applied in processing equipment that contacts water-based fluids. Processing equipment in oil and gas operations may include separators, treaters, and other vessels where metal surfaces are exposed to water-containing process streams. The anti-corrosion composition may protect processing equipment surfaces by providing multi-mode corrosion control within the water-based fluid environment. The anti-corrosion composition may be applied in manufacturing facilities. In some cases, the anti-corrosion composition is applied in process water systems within manufacturing facilities. Process water systems in manufacturing facilities may supply water for various industrial processes where metal piping, valves, and equipment are exposed to aqueous environments. The anti-corrosion composition may protect metal surfaces within process water systems by providing electrochemical stabilization and preventing differential corrosion. In some cases, the anti -corrosion composition is applied in heat exchangers within manufacturing facilities. Heat exchangers in manufacturing facilities may transfer heat between process streams and cooling water, creating conditions where metal surfaces are exposed to aqueous environments on one or both sides of the heat transfer surface. The anticorrosion composition may protect heat exchanger surfaces by forming protective films and preventing scale formation that could create localized corrosion sites. In some cases, the anticorrosion composition is applied in other equipment within manufacturing facilities where metal surfaces are exposed to aqueous environments. The anti-corrosion composition may protect metal surfaces in pumps, tanks, and other equipment by providing the combined effects of anodic passivation, cathodic inhibition, surface passivation, and pH buffering.
[0168] The anti-corrosion composition may be applied in water treatment applications. In some cases, the anti-corrosion composition is applied in municipal water systems. Municipal water systems may include water distribution networks, storage reservoirs, and treatment facilities where metal pipes and equipment are exposed to treated water. The anti -corrosion composition may protect metal surfaces within municipal water systems by maintaining pH homeostasis and providing surface passivation. In some cases, the anti-corrosion composition is applied in industrial wastewater treatment facilities. Industrial wastewater treatment facilities may process water containing various contaminants and may include metal tanks, piping, and equipment that are exposed to corrosive wastewater streams. The anti-corrosion composition may protect metal surfaces within industrial wastewater treatment facilities by chelating metal ions, providing pH buffering, and forming protective barriers on metal surfaces exposed to the wastewater environment.
Claims
CLAIMS1. A biobased, biodegradable, multi-functional anti-corrosion composition for waterbased industrial systems, comprising:a first non-ionic surfactant comprising polysorbate 20;a second non-ionic surfactant comprising polysorbate 80;a phosphonate chelating agent comprising etidronic acid;a first organic acid comprising lactic acid;a second organic acid comprising acetic acid;an organic ester comprising ethyl lactate; andan aqueous medium comprising deionized water,wherein the composition integrates means for anodic passivation, means for cathodic inhibition, means for surface passivation, and means for pH buffering for providing multi-mode corrosion control within a single formulation, and wherein the composition is free of phosphates and polyacrylates.
2. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in claim 1, wherein:Polysorbate 20 is present in an amount of 1 wt% to 15 wt% of the total composition;the polysorbate 80 is present in an amount of 1 wt% to 20 wt% of the total composition; the etidronic acid is present in an amount of 0.5 wt% to 10 wt% of the total composition; the lactic acid is present in an amount of 5 wt% to 30 wt% of the total composition;the acetic acid is present in an amount of 2 wt% to 15 wt% of the total composition;the ethyl lactate is present in an amount of 1 wt% to 15 wt% of the total composition; and the deionized water constitutes the balance to 100 wt% of the total composition.
3. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in claim 1 or 2, wherein the polysorbate 20 acts as a cathodic-type inhibitor by forming selfassembling monolayers on carbon steel surfaces, thereby creating a barrier between the metal surface and corrosive agents present in the aqueous environment.
4. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in any one of claims 1 to 3, wherein the polysorbate 80 acts as a mixed-type corrosion inhibitor affecting both anodic and cathodic corrosion reactions through adsorption on metal surfaces, thereby facilitating uniform distribution of active components on the metal surface.
5. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in any one of claims 1 to 4, wherein the etidronic acid acts as a chelating and scale-inhibiting agent by forming stable chelate complexes that sequester free metal ions that would otherwisecatalyze corrosion processes and by preventing scale formation through binding with scaleforming ions including calcium ions and magnesium ions.
6. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in any one of claims 1 to 5, wherein the lactic acid and the acetic acid provide pH buffering for maintaining system acidity within a functional pH range of 3.0 to 4.0, and wherein the lactic acid acts as an electron scavenger to inhibit the active electron cycle responsible for metal surface oxidation.
7. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in any one of claims 1 to 6, wherein the ethyl lactate adsorbs onto metal surfaces through interactions between an ester functional group and metal ions to form a protective barrier against corrosion-inducing agents including oxygen, chloride ions, and moisture, and wherein the ethyl lactate undergoes controlled hydrolysis to release lactate ions that complex with free metal ions to stabilize the electrochemical environment.
8. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in any one of claims 1 to 7, wherein the composition exhibits synergistic iron-binding capacity of 54 mg of Fe3+that exceeds the iron-binding capacity of any individual ingredient, and wherein the composition exhibits buffering capacity approximately five-fold higher than a theoretical additive buffer capacity calculated from proportional raw material buffering values at equivalent effective concentrations.
9. A biobased, biodegradable, multi-functional anti-corrosion composition for waterbased industrial systems, comprising:at least two non-ionic surfactants selected from polysorbate 20 and polysorbate 80;a phosphonate chelating agent comprising etidronic acid;at least two organic acids selected from lactic acid and acetic acid;an organic ester comprising ethyl lactate; andan aqueous medium comprising deionized water,wherein the composition integrates means for anodic passivation, means for cathodic inhibition, means for surface passivation, and means for pH buffering for providing multi-mode corrosion control within a single formulation, wherein the composition is free of phosphates and polyacrylates, and wherein the composition is effective at concentrations between 0.05% and 0.5% for corrosion suppression in water-based coating systems.
10. The biobased, biodegradable, multi-functional anti-corrosion composition as claimed in claim 9, wherein the composition exhibits a biobased carbon content of 99% within specified concentration ranges of the constituent components, and wherein the composition demonstrates a biodegradability of at least 96% as measured according to OECD 301 D closed bottle test methodology.