CO2 Corrosion Inhibitors Performance at Deposit-Covered Carbon Steel and Their Adsorption on Different Deposits (original) (raw)
Related papers
Applied Surface Science, 2004
Morphological and compositional studies were conducted on the corrosion layers formed on carbon steel with two different heat treatments in chloride media containing CO 2 by means of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The performance of three imidazoline-like compounds as corrosion inhibitors was analyzed. Aminopropylimidazol (API) and two commercial imidazoline-based products (PC and QB) were used with this purpose. The corrosive media was a deoxygenated 5% NaCl solution, CO 2 saturated at pH 6 at 40 8C. XPS results indicated that, independently of the steel microstructure, FeCO 3 was present among the corrosion products when API and PC were used, while an inhibitor protective film formed with the addition of QB. However, the ratio of the various compounds present was influenced by the microstructure of the base material. On the other hand, it is concluded that the molecular structure of the compounds employed as inhibitors seems to have a main role on their performance in the studied experimental conditions.
Inhibitors performance in CO2 corrosion
Corrosion Science, 2005
The performance of three imidazoline-like inhibitors in CO 2 corrosion was studied by means of electrochemical measurements employing a.c. and d.c. techniques. Carbon steel with two different microstructures (annealed, and quenched and tempered (Q&T)) was used in a deoxygenated 5% wt. NaCl solution, saturated with CO 2 at 40°C and pH 6. Aminopropylimidazol (API) and two commercial imidazoline-based products (PC and QB) were used as inhibitors. Electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LRP) studies showed that the annealed samples have a better corrosion resistance than the Q&T samples when API and PC were added. On the other hand, the presence of QB yielded the opposite results. From the Bode phase angle plots it can be concluded that in the first case and for both microstructural conditions, there is no indication of formation of an inhibitor film, whereas in the presence of QB its formation is clearly evident. Based on these experimental findings, a mechanism of action for each inhibitor is proposed.
Carbon Dioxide Corrosion Inhibitors - A review
This article intends to summarize the corrosion inhibition of pipeline steels in aqueous carbon dioxide (CO2) environments. The emphasis is on various inhibitors, especially imidazolines used to mitigate mild steel corrosion under various conditions. The most predominant and feared type of corrosion attack in oil and gas industries is caused by CO2.The application of corrosion inhibitors is considered the most suitable method of combating CO2 corrosion of steel pipelines. The prime objective of this work is to summarize carbon dioxide corrosion inhibitors so far tested and reported against this type of attack. The information presented in this article is of significance for oil and gas industries that use steel pipeline for the transportation of oil and gas products. Furthermore, this review would be helpful in designing better inhibitors for the mitigation of CO2 corrosion in oil and gas industries.
Inhibition of CO2 corrosion of carbon steel with 1% Cr
Materials Chemistry and Physics, 2012
h i g h l i g h t s < The imidazoline-based inhibitor used has a lower performance on carbon steel with 1% Cr. < Inhibitor adsorption kinetics were enhanced with the increase of rotation rate. < Fluid flow velocity may be an important parameter for the inhibition of carbon steel with 1% Cr. < Effective inhibition of carbon steel with 1% Cr was achieved only at higher rotation rates. < Localized corrosion was found for carbon steel with 1% Cr inhibited at the lower rotation rate.
Scientific Reports, 2018
The efciency of generic and proprietary corrosion inhibitors (based on nitrite, amine carboxylate or amino alcohol) in corrosion mitigation of carbon steel, which is exposed to concrete solutions with diferent amounts of chloride as well as sulfate, was studied. The corrosion protection provided by the selected corrosion inhibitors was investigated by performing a potentiodynamic polarization study. In addition, the surface morphological properties of carbon steel samples exposed to the electrolyte mixed with or without inhibitors was also evaluated by scanning electron microscopy. The potentiodynamic polarization measurements showed that the evaluated inhibitors decreased the corrosion current density by 1.6 to 6.7 times depending on the type of inhibitor and the level of sulfate concentration in the electrolyte. The performance of inhibitors based on nitrite was better than that of inhibitors based on amine carboxylate or amino alcohol. The possible mechanisms of the inhibition in the chloride plus sulfate environments are also elucidated.
Sweet Corrosion Inhibition by CO2 Capture
Molecules
The most practical and economical way to combat the problems derived from CO2 corrosion (sweet corrosion) is the use of corrosion inhibitors of organic origin. Its main protection mechanism is based on its ability to adsorb on the metal surface, forming a barrier between the metal surface and the aggressive medium. However, despite its excellent performance, its inhibition efficiency can be compromised with the increase in temperature as well as the shear stresses. In this study, the use of an inorganic inhibitor is proposed that has not been considered as an inhibitor of sweet corrosion. The reported studies are based on using LaCl3 as a corrosion inhibitor. Its behavior was evaluated on 1018 carbon steel using electrochemical measurements, such as potentiodynamic polarization curves, open-circuit potential measurements, linear polarization resistance measurements, and electrochemical impedance. The results showed an inhibition efficiency of the sweet corrosion process greater than...
Cement and Concrete Research, 2014
In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH) 2 solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH) 2 solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface.
The effect of pre-corrosion and steel microstructure on inhibitor performance in CO2 corrosion
Corrosion Science, 2008
The importance of chemical composition and microstructure on CO 2 corrosion of carbon and low alloy steels has been widely recognized, still contradictory results can be found in the literature. The aim of this work is to assess the relationship between microstructure, surface condition and inhibitor efficiency in CO 2 corrosion. A C-Mn steel with two different microstructures was tested in a deoxygenated 5% wt. NaCl solution saturated with CO 2 at 40°C, pH 6. A commercial imidazoline-based inhibitor was added after different pre-corrosion periods. The results obtained showed that pre-corrosion decreases the inhibitor efficiency, but that its impact is microstructure dependent.
Journal of Chemistry, 2014
In order to determine the diesel contribution in the coadsorption process of the oil-soluble inhibitors, electrochemical impedance spectroscopy measurements have been carried out to study the performance of oil-soluble inhibitors in both presence and absence of diesel and CO 2 . The results showed that the presence of the oil phase provides some protection to the steel because the watersoluble fractions are capable of being adsorbed on the steel surface thereby reducing the corrosion rate. The oily phase does not contribute to the adsorption process of the inhibitor because the inhibitor is absorbed into the water-soluble fractions. The oilsoluble inhibitors are effective only when the solution is saturated with CO 2 . CO 2 saturation causes a decrease in the pH of the solution causing both an increase of the inhibitor solubility and a better dispersion of the inhibitor into the electrolyte.
Metals
In the present work, we represent two thiazolidinediones, namely (Z)-5-(4-methoxybenzylidene) thiazolidine-2,4-dione (MeOTZD) and (Z)-5-(4-methylbenzylidene) thiazolidine-2,4-dione (MeTZD), as corrosion inhibitors for carbon steel (CS) in 1.0 M HCl solution. Techniques for gravimetric methods, electrochemical measurements, and morphological characterization were used to conduct experimental evaluations. Additionally, calculations based on the fundamental principles of Density Functional Theory (DFT) were employed to simulate inhibitor–iron interactions. Experimental results indicated that investigated inhibitors can significantly enhance the corrosion resistance of CS, reaching a performance of 95% and 87% at 5 × 10−3 mol/L of MeOTZ and MeTZD, respectively. According to gravimetric and electrochemical experiments, inhibitor molecules obstruct corrosion reactions by adhering to the CS surface, which follows the Langmuir isotherm model. On the other hand, the morphological analysis sh...