Volatile Corrosion Inhibitors Research Articles

Study on the Performance and Mechanism of Morpholine Salt Volatile Corrosion Inhibitors on Carbon Steel

A series of morpholine salt volatile corrosion inhibitors (VCIs) were synthesized via solid-phase chemical reactions. The corrosion inhibition performance was assessed using evaporation weight loss, VCI capability, and corrosion weight loss tests. The corrosion inhibition mechanisms of the morpholine salt VCIs for carbon steel in atmospheric conditions were explored through electrochemical testing under thin film electrolytes, X-ray photoelectron spectroscopy (XPS), and computational simulations. Morpholine carbonate exhibited higher volatility. Corrosion weight loss tests showed an >85% reduction for steel treated with morpholine benzoate or morpholine carbonate. The inhibitors’ inhibition mechanism, elucidated through X-ray photoelectron spectroscopy (XPS) and computational simulations, revealed that morpholine carbonate and benzoate form protective layers via physical and chemical adsorption on the steel surface, coordinating with iron atoms through nitrogen and oxygen atoms. Quantum chemical calculations demonstrated that morpholine carbonate had stronger adsorption energy and electron transfer capabilities, indicating superior corrosion inhibition performance over morpholine benzoate.

Eco-friendly grinding: exploring the potential of volatile corrosion inhibitors

Eco-friendly grinding: exploring the potential of volatile corrosion inhibitors

Unlocking the Potential of VCI Films: A Comprehensive Study on Protective Efficiency

ABSTRACT Volatile Corrosion Inhibitor films have become an essential tool in safeguarding metal surfaces from corrosion. To maximize the effectiveness of VCI films, it is crucial to understand the relationship between their thermal properties and vapor phase inhibition ability. In this study, the optimal and modified standard test was performed for evaluation of VCI films ability and also investigate how their thermal characteristics influence their protective efficiency via the weight-loss method, and differential scanning calorimetry (DSC) analysis. The results showed that under the simulated and standard test conditions, the steel surface exposed to VCI films shows a model of a “preservative memory for VCI material”, at higher temperature/humidity. This memory is affected by different adsorption power due to the roughness of the surface, humidity and temperature as well as the rate of release of inhibitors. The results of the computational method confirmed that the orientation of the inhibitor molecule when interact with the polymer chain is the determining factor in the inhibition efficiency, consistent with the FTIR results. This behavior caused by chemical or electrochemical reaction with the temperature-dependent release rate of inhibitors has a greater effect on inhibition.

Imidazoline As a Volatile Corrosion Inhibitor for Mitigation of Top- and Bottom-of-the-Line CO2 Corrosion in Carbon Steel Pipelines.

A fatty acid imidazoline-based inhibitor was synthesized via a facile solvent-free synthesis method between tall oil fatty acid (TOFA) and diethylenetriamine (DETA) under atmospheric conditions with a short reaction time. The as-synthesized imidazoline (S-Imd) acted as an effective inhibitor for reducing or preventing corrosion of carbon steel pipelines at both bottom of the line (BOL) and top of the line (TOL) positions under simulated conditions of a gas pipeline in a CO2-saturated environment. The inhibition efficacy was examined by both weight loss and electrochemical measurements, such as the electrochemical impedance spectrum (EIS), potentiodynamic polarization (PDP), and linear polarization resistance (LPR). The results revealed that the S-Imd, 2-(8-heptadecenyl)-2-imidazoline-1-ethanamin, at 300 ppm exhibited a superior inhibition efficiency of up to 91.6 and 89.9% for BOL and TOL corrosion tests, respectively. The surface morphology of the carbon steel test specimens was also examined using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), and contact angle analysis. It was found that the as-synthesized S-Imd acted as a mixed-type inhibitor that exhibited a decreased surface roughness and oxide layer on carbon steel surfaces. However, the water contact angle was found to increase, implying enhanced hydrophobicity of the surface. Adsorption of the imidazoline molecules on carbon steel surfaces followed the Langmuir adsorption isotherm. The present work provides very promising results in the synthesis and utilization of the studied imidazoline as a volatile corrosion inhibitor (VCI), especially for carbon steel pipelines in petroleum industries.

NON-CARCINOGENIC VCI SOLUTION FOR LONG TERM METAL PROTECTION

Corrosion is a dangerous and extremely costly problem. Because of it, buildings and bridges can collapse, oil pipelines break, chemical plants leak, and bathrooms flood. Corroded electrical contacts can cause fires and other problems, corroded medical implants may lead to blood poisoning, and air pollution has caused corrosion damage to work around the world. Corrosion threatens the safe disposal of radioactive waste that must be stored in containers for tens of thousands of years. When reduction and oxidation take place on different kinds of metal in contact with one another, the process is called galvanic corrosion. In electrolytic corrosion, which occurs most commonly in electronic equipment, water or other moisture becomes trapped between two electrical contacts that have an electrical voltage applied between them. The result is an unintended electrolytic cell. VCI is the generic term for “volatile corrosion inhibitor” a revolutionary technology that simplifies corrosion protection and is ideal for keeping enclosed void spaces (e.g., packages, equipment internals, or structural metal cavities) rust-free. Keywords: Corrosion; VCI; Rust.

Efficiency of Volatile Corrosion Inhibitors in the Presence of n-Heptane: An Experimental and Molecular Simulation Study

Volatile corrosion inhibitors (VCIs), specifically formulations based on thiols and amines, can be used to mitigate top-of-the-line corrosion (TLC) that arises during the transportation of wet gas through transmission pipelines. Nevertheless, the VCI inhibition efficiency (IE) can be compromised by the presence of condensable hydrocarbon phases. In this research, the IE of two thiol compounds (decanethiol and hexanethiol) and three combinations of VCIs for TLC scenarios, both in the presence and absence of n-heptane, representing a condensing hydrocarbon phase were studied. The results proved the IE of thiols in a water-only condensing environment, with effectiveness increasing with the alkyl tail length. Conversely, in a water/n-heptane co-condensing environment, a reversed trend was observed, where hexanethiol exhibited higher corrosion IE compared to decanethiol. Molecular simulation results indicated a synergistic adsorption behavior when the alkane was of a similar length as the alkyl tails of the inhibitors, leading to the incorporation of alkane molecules with the inhibitor molecules. A mixture of thiols (decanethiol and hexanethiol) and two mixtures of thiol and amines (decanethiol and diethylamine/t-butylamine) were also considered in both water-only and water/n-heptane co-condensing environments. In the presence of n-heptane, only the thiol mixture, featuring molecules with different tail lengths, demonstrated high IE. This behavior was attributed to the superior IE provided by thiol-based molecules with a shorter alkyl tail (hexanethiol) in the presence of n-heptane. Additionally, the results revealed that the mixtures of decanethiol and amines did not enhance corrosion inhibition in the presence of n-heptane within the system.

An improved protection of alanine for atmospheric corrosion of mild steel using carbon dots-montmorillonite hybrid materials

PurposeThe aim of this paper is to solve the toxic and harmful problems caused by traditional volatile corrosion inhibitor (VCI) and to analyze the effect of the layered structure on the enhancement of the volatile corrosion inhibition prevention performance of amino acids.Design/methodology/approachThe carbon dots-montmorillonite (DMT) hybrid material is prepared via hydrothermal process. The effect of the DMT-modified alanine as VCI for mild steel is investigated by volatile inhibition sieve test, volatile corrosion inhibition ability test, electrochemical measurement and surface analysis technology. It demonstrates that the DMT hybrid materials can improve the ability of alanine to protect mild steel against atmospheric corrosion effectively. The presence of carbon dots enlarges the interlamellar spacing of montmorillonite and allows better dispersion of alanine. The DMT-modified alanine has higher volatilization ability and an excellent corrosion inhibition of 85.3% for mild steel.FindingsThe DMT hybrid material provides a good template for the distribution of VCI, which can effectively improve the vapor-phase antirust property of VCI.Research limitations/implicationsThe increased volatilization rate also means increased VCI consumption and higher costs.Practical implicationsProvides a new way of thinking to replace the traditional toxic and harmful VCI.Originality/valueFor the first time, amino acids are combined with nano laminar structures, which are used to solve the problem of difficult volatilization of amino acids.

Inhibition for atmospheric corrosion of mild steel by lysine salts with graphene oxide interlayer in situ modulation

In this paper, an environmentally friendly volatile corrosion inhibitor, lysine salts (LA), was prepared between graphene oxide (GO) layers by in situ intercalation technique and its corrosion inhibition effect was evaluated. The results indicated that the pore structure of GO facilitated the dispersion of LA molecules and improved the volatility. LA-GO2 achieved a 99.3% corrosion inhibition efficiency after composition optimization, mainly due to its significant inhibition of the electrochemical anodic process on the surface of mild steel. Moreover, the properties of the surface film on the corroded steel were also characterized in detail to reveal the corrosion inhibition mechanism of LA-GO2.

The effectiveness of some volatile corrosion inhibitors in conditions of intense condensation of moisture

The effectiveness of some volatile corrosion inhibitors in conditions of intense condensation of moisture

Protection of metals from corrosion in the vapor phase. Overview. Part 1. Volatile corrosion inhibitors

Protection of metals from corrosion in the vapor phase. Overview. Part 1. Volatile corrosion inhibitors

Insights into the Molecular Motion of Benzotriazole in the Volatile Corrosion Inhibitor Packaging: A Detection and Mass Transfer Study

A new methodology using microwave extraction, gas-diffusion microextraction (GDME) and high-performance liquid chromatography-mass spectrometer (HPLC-MS) was developed for the analysis of the quantitative detection of gaseous and solid benzotriazole (BTA) and the mass transfer behavior of BTA in volatile corrosion inhibitor (VCI) packaging. The best extraction conditions of BTA in the VCI films were obtained, and the vapor pressure of BTA in the VCI packaging was detected and characterized by a mathematical model using the new methodology. The migration content of BTA in the VCI films and the BTA content on the surface of the films were detected, and the diffusion coefficients at three temperatures were calculated. The vapor pressure and diffusion coefficients of BTA increased with increasing temperature, and the volatilization of BTA promoted the migration of BTA from the VCI films. Moreover, a molecular dynamics (MD) simulation was performed to determine the migration of the BTA molecules within the VCI films at three temperatures; the overall trend of the experimental values was the same and the simulated values were generally within two orders of magnitude of the corresponding experimental values, with the difference likely due to the ignoring of the crystallinity of LDPE.

Performance of a Volatile Corrosion Inhibitor for Mitigating Corrosion Under Insulation

This study evaluated the efficacy of a commercial volatile corrosion inhibitor (VCI) in mitigating the corrosion of carbon steel insulated with mineral wool insulation, especially as a retrofitted solution to corrosion under insulation (CUI) management. When VCI was added in dry insulation before the test solution was introduced, the severity of CUI was reduced after 14 d of exposure. However, when the exposure time was extended to 90 d, no significant mitigation effect was observed. Furthermore, VCI was ineffective when added to precorroded insulated systems, indicating that it could not be used as a retrofitted solution to alleviate CUI problems. A separate set of tests with bare steel samples exposed to 10 mL VCI in closed jars showed that VCI was adsorbed on the corrosion products but could not effectively impede the propagation of localized corrosion. The possible influences of insulation jacketing, insulation properties, VCI dosages, and dosing methods were also discussed, suggesting the need for further investigations.

Study of volatile corrosion inhibitors by infrared spectroscopy

In practice, it often becomes necessary in practice to identify a particular substance or chemical product as a whole, and also to quantify their content in the developed material. Corrosion inhibitors are special chemicals that retard the process of chemical and physical reactions. Determination of the minimum permissible concentration of the inhibitor in anticorrosive papers has an important practical significance because it specifies the duration of their protective effect. The possibility of practical application of infrared (IR) spectroscopy is considered in the study of structural features of volatile corrosion inhibitors and packaging materials with these inhibitors. Koring 501, Koring 505 inhibitors of Cortec Corporation (USA) and UNI inhibitor (a mixture of sodium nitrite and urotropine in a ratio of 1:1, Russia) were used as volatile corrosion inhibitors for anticorrosive packaging materials preparation. Aqueous solutions of inhibitors containing 5 % (wt.) of the active substance were applied on the surface of creped paper with thermoplastic polymer lamination on one side by roller method. IR spectra of pure inhibitors and inhibited samples of packaging material were plotted on an IR Fourier spectrometer FT 801. The IR spectra of each inhibitor exhibit peaks that are unique to it. This will allow the inhibitors to be distinguished from each other. It was found by means of IR analysis that the composition of foreign inhibitors includes compounds containing nitrite ions (NO2‒). It is shown that the IR spectroscopy can be used to control the quality of the anticorrosive packaging materials. This is particularly topical in the conditions of import substitution.

APPLICATION OF METHODS FOR DETERMINATION OF THE VOLATILE CORROSION INHIBITORS CONTENT IN COMBINED PACKAGING MATERIALS

One of the modern means of corrosion protection of metal products during transportation and storage is packaging materials containing volatile corrosion inhibitors. The efficiency of the metal protection is highly dependent on their content in the packaging materials. Present study considers the peculiarities of practical application of Synchronous Thermal Analysis method and Walki Wisa (Finland) method for determination of the corrosion inhibitor content in packaging combinations. The packaging materials used in the study were the crepe paper laminated with thermoplastic polymer on one side, onto which the water solutions of inhibitors Koring 501, 505 (Cortec, USA) and UNI (a mixture of sodium nitrite and urotropine in relation 1:1, Russia) containing 5 % (mas.) of active substance were applied with a roller. After application of the solution the paper was subjected to drying at 80 °C for 35 min. The residual content of inhibitors was determined by two methods: thermogravimetric analysis using STA 449 F3 Jupiter and the method of washout according to the Walki Wisa method. It was shown that washout method requires preliminary isolation of inhibitor from packing material in the form of its aqueous extract. It was found that the inhibitor content indices obtained by the washout method have higher values compared to the initial samples which is probably caused by the water extraction of other components from combined material together with the inhibitor. The content of the inhibitor in the materials under study and the temperature of the maximum rate of inhibitor volatilization were determined by the thermogravimetric analysis. The sample with UNI inhibitor had the highest inhibitor content (13 %) and a higher maximum volatilization temperature compared to the other samples. This may be due to the overlapping processes of urotropin removal and cellulose fibers decomposition. The method of thermogravimetric analysis can be applied for determination of the inhibitors removing up to 200 °C. It is noted that both considered methods have certain limitations and can be used for approximate determination of the inhibitor content in paper-based composite packaging materials.

Development of a novel setup for in-situ electrochemical assessment of top of the line corrosion (TLC) and its smart inhibition under simulated conditions

Top of the line corrosion (TLC) is one of the main root causes for many multiphase pipeline failures in the upstream oil and gas industry. The most challenging issue for assessment of TLC in multiphase pipelines is simulating the operational conditions to find out the governing mechanisms of corrosion and its inhibition. The current work aimed to develop a novel setup for evaluating the TLC and its inhibition using the in-situ electrochemical techniques under simulated conditions. Moreover, since one of the major influencing factors in TLC is the pressure of acid gases (CO2 and H2S), an autoclave was designed to provide the feasibility of in-situ electrochemical experiments under pressurized conditions. Specialized probes were developed and placed at both the top and bottom of the autoclave to study and compare the corrosion behavior and inhibition performance at both locations. To check the function of the setup, different experiments, including electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization scanning (PDS), and linear polarization resistance (LPR) were conducted in different conditions. The performance of the system was validated by comparing the electrochemical results with weight loss coupons in autoclave and a field study in actual conditions The capability of the setup for evaluating the smart inhibition of TLC was checked with an amine-based volatile corrosion inhibitor and confirmed by EIS.

Some Results of Tensimetric Studies of Volatile Corrosion Inhibitors

Some Results of Tensimetric Studies of Volatile Corrosion Inhibitors

Surface modification for Al alloy by volatile corrosion inhibitors from cyclohexylamine, octanoic acid, and their reaction product

AbstractThe protection for Al alloy is investigated through vapor phase assembly technology. The corrosion resistance performance of the assembled Al alloys is compared by the electrochemical measurements as well as hydrogen evolution test. The assembly sequence affects the protection of the complex films formed on Al alloy surface. It indicates that the complex films of base and acid assembly components have better protection effects. The reactivity between the assembly components and the formation mechanism of the complex films is analyzed. The alternative assembly of acid and base components enhances the anticorrosion ability of Al alloys and becomes the promising method for the use of the salt‐type volatile corrosion inhibitor.

New generation of mixed volatile corrosion inhibitors IFKHAN and materials based on them

New generation of mixed volatile corrosion inhibitors IFKHAN and materials based on them

Volatile mix corrosion inhibitors of ferrous metals and universal preparations

Volatile mix corrosion inhibitors of ferrous metals and universal preparations

Controlled Release of Novel Volatile Corrosion Inhibitor (VCI) Nanoparticles Incorporated in Low Density Polyethylene (LDPE) Films for Steel Coverings: Correlation of Experimental Results with Molecular Dynamics Simulation

The compositions of 10 different VCI compounds were optimized. Low density polyethylene (LDPE), ECA-5 copolymer (poly(ethylene-co-methyl acrylate) as an ethylene based coupling agent) and the prepared VCI compound, so called BFA-200, were processed in a twin screw extruder followed by a film casting method to make films. The 80/20 LDPE/ECA-5 composition was determined as the optimized VCI unfilled blend having the maximum mechanical properties for the film processing; the BFA-200 VCI nanoparticles (5, 10 and 15%) were added to this composition. Measurement of the controlled release of the VCI within the LDPE/ECA-5/BFA-200 80/20/15 sample was carried out using thermo-gravimetric analysis (TGA). The TGA method was also used for determination of the VCI content after periods of 3, 6 and 12 months in polyethylene bags stored at ambient conditions. There was a significant difference in the release of VCI agent for the blends as compared to that of VCI incorporated in only LDPE. The preservative quality of the blend films was tested on steel plates using the TL8135-002 standard. There were acceptable degrees of corrosion with all of the virgin blends containing BFA-200, especially 10% upward. However, there was a different behavior after each time period, in good accordance with the release tests. Moreover, a molecular dynamics (MD) simulation was performed to determine the diffusion of the VCI molecules within pure LDPE and the LDPE/ECA-5 blends. There was a decrease in the simulated diffusion of the VCI material through the blends with addition of the ECA-5 content which fitted well to the experimental data.