Carbon Steel In CO2 Research Articles

Synergism of alkylbenzene sulfonate and cetyltrimethylammonium bromide on corrosion inhibition of carbon steel in CO2 -saturated solutions

The synergistic effect of mixed surfactants, linear alkylbenzene sulfonate (LAS) and cetyltrimethylammonium bromide (CTAB), in inhibiting corrosion of CO2 on carbon steel was studied by weight loss and electrochemical measurement. The surface properties of LAS, CTAB, and their mixture in solution were also studied by surface tension and phase behavior. The surface of corrosion specimens was characterized by infrared spectroscopy, scanning electron microscopy, contact angle, and atomic force microscopy. The results show that LAS, CTAB, and their mixture are inhibitors mainly inhibiting anode reactions. The adsorption of LAS and CTAB molecules on the surface of steel belongs to chemical adsorption and follows Temkin adsorption. LAS or CTAB alone aggregated form spherical micelles or rod-like micelles, which results in the defective film layer and localized corrosion on surface of the steel. Mixed surfactants form closely packed lamellar microstructure in the solution which is correlated to compact adsorption film on the metal surface and better corrosion inhibition. The inhibition efficiency is the highest when the mixed ratio of LAS and CTAB is 2:1.

Synergism of 2-mercaptobenzimidazole and oleic imidazoline on corrosion inhibition of carbon steel in CO2 -saturated brine solutions

The inhibition properties of 2-mercaptobenzimidazole (MBI) and its synergism with oleic imidazoline (OIM) for carbon steel in CO2-saturated brine solution were investigated by electrochemical, weight loss measurements, surface analysis and quantum chemical calculations. The effectiveness of MBI for OIM was also compared to the other sulfur-containing corrosion inhibitors such as 2-mercaptothanol (ME), mercaptoacetic acid (TGA), and thiourea (TU). The results show that a mixture of MBI and OIM gave a better synergistic corrosion inhibition than that of ME, TGA, and TU. OIM is protonated and coupled with MBI by hydrogen bonding to co-adsorb on the carbon steel surface. MBI adsorbs on Fe by a bidentate bindingNSbridge connection, which effectively prevents the carbon steel from CO2 corrosion.

Adsorption and corrosion inhibition characteristics of 2–(chloromethyl)benzimidazole for C1018 carbon steel in a typical sweet corrosion environment: Effect of chloride ion concentration and temperature

Benzimidazole derivatives are emerging as promising corrosion inhibitors for oil and gas application because they exhibit high efficiency and very good environmental profile. Although long alkyl and phenyl chains enhance their efficiency, they also increase their toxicity. Finding benzimidazole derivatives devoid of long hydrocarbon chains and with lower toxicity has become a priority. 2–(chloromethyl)benzimidazole (CMB), with log Po/w = 2.2, has been investigated as a promising low-toxic sweet corrosion inhibitor for C1018 carbon steel in CO2–saturated NaCl solution under static condition using experimental and theoretical approaches. At 25 °C, Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques confirm that CMB is an anodic-type sweet corrosion inhibitor which is able to form a protective layer on the steel surface and provide inhibition efficiency of 97.54% at 10 ppm. The efficiency increased to 98.40% and 98.58% upon increasing the temperature to 40 °C and 60 °C, respectively but decreased to 96.32% and 94.76% as the salt concentration was raised to 5.0% and 7.0% NaCl, respectively. The latter was attributed to the antagonistic competition between Cl– ions and CMB for anodic adsorption. The CMB–steel interaction is facilitated by the free electrons around N heteroatoms and C = C bonds, based on FTIR analysis and computational calculations. This eventually ameliorates the surface degradation of the steel during the sweet corrosion at 25 and 60 °C. CMB performance is highly comparable with reported sweet corrosion inhibitors with higher toxicity values.

Investigation of the corrosion inhibition performances of various inhibitors for carbon steel in CO2 and CO2/H2S environments

ABSTRACT The corrosion inhibition performances of thiourea (TU), l-cysteine (CYS), sodium dodecyl sulfonate (SDS), tetradecyl trimethyl ammonium bromide (TTAB), N-benzyl pyridinium chloride (BPC) and imidazoline quaternary ammonium salt (IAS) in CO2-saturated and CO2/H2S coexistent brine solutions were investigated by electrochemical measurement, weight-loss test, molecular dynamics simulation and SEM observation. The results show that H2S can remarkably affect the adsorption of some inhibitors on the steel surface and the inhibition performance. In detail, the inhibition performances of TU, CYS and SDS, which are effective in the CO2 environment, deteriorate in the CO2/H2S environment. However, the cationic inhibitors (TTAB, BPC and IAS) exhibit good inhibition performance in the CO2/H2S environment possibly because of a relatively strong interaction between inhibitor cations and HS− ions. The finding of this study delivers a provable method to predict the performance of inhibitors in the aggressive solution containing H2S.

An electrochemical study on the effect of bicarbonate ion on the corrosion behaviour of carbon steel in CO2 saturated NaCl solutions

The electrochemical study on the effect of HCO3− on the corrosion behaviour of carbon steel in CO2 saturated NaCl solutions was investigated through mathematical calculation of impedance plots and potentiodynamic polarization. Results reveal that a competitive adsorption between HCO3−/Cl− exists, and HCO3− is able to reduce and/or replace the adsorption of Cl− on carbon steel surfaces with the elevation of HCO3− concentration. In addition, at the certain condition (CO2-saturated solution containing 0.1 M Cl−), carbon steel tends to passivate when HCO3− concentration reaches 0.5 M. However, pitting can be triggered in 0.2 M HCO3− concentration. The findings of this work spot light on the understanding of many parameters related to this process, which is of great significance to prevent the underlying corrosion failure and prolong the lifespan of carbon steel pipelines in the service environment.

Corrosion study of carbon steel in CO2 loaded solution of N-methyldiethanolamine and l-arginine mixtures

This study presents an electrochemical corrosion investigation of carbon steel in blends of methyldiethanolamine (MDEA) and arginine (ARG) at different molar concentrations and solvent proportions. The effects of three main parameters which are CO2 partial pressure, solution temperature and MDEA/ARG proportions ratio were studied. The selected temperatures range varied from 293 to 323K and the CO2 partial pressure was in the range of 49–98kPa. The results showed that the corrosion rate increased with increased CO2 partial pressure and solution temperature. However, when ARG was added to MDEA, it was found that ARG acts as an inhibitor, the higher ARG fraction in the mixture, the more inhibition effect was observed. SEM, XRD, and XPS techniques were used to characterize the corroded surfaces; analysis of the corrosion products of the specimen surface confirmed the formation of FeCO3 protective layer.

3-Mercaptopropionic Acid as Corrosion Inhibitor for Carbon Steel in CO2 Aerated 1% NaCl Solution with Buffer Control-pH

In this research, 3-Mercaptopropionic acid (MPA) as corrosion inhibitor of carbon steel in CO2 aerated 1% NaCl solution with buffer pH adjustment has been studied by means of electrochemical impedance (EIS) and polarization (Tafel plot). MPA was found to be an effective carbon steel inhibitor. Percentage inhibition efficiency (IE %) calculated by both Tafel plot and EIS, ranged from 85% to 90%. MPA was found to affect the cathodic processes and act as cathodic-type inhibitors. Mechanism of inhibit corrosion by adsorption mechanism leads to the formation of a protective chemisorbed film on the metal surface film which suppresses the dissolution reaction and the hydrogen evolution reaction is activation controlled.

Corrosion Study of Carbon Steel in CO2 Loaded Amine-Amino Acid Solutions-Case of Mixtures of NMethyldiethanolamine and L-Arginine

This research presents an electrochemical corrosion investigation to quantify the corrosiveness of carbon steel in blends of methyldiethanolamine (MDEA) and arginine (Arg) at two molar concentration and different solvent proportions. The selected temperatures range varied from 20 °C to 50 °C and the CO2 partial pressure was in the range of 49-100 kPa. The obtained data showed increased corrosion rate with increased CO2 partial pressure and increased the temperature of the solution. However, when added to MDEA, arginine was found to act as an inhibitor, the higher Arginine proportion in the mixture, the more inhibition effect was observed.

Application of Anise Extract for Corrosion Inhibition of Carbon Steel in CO2 Saturated 3.0% NaCl Solution

The corrosion inhibition of carbon steel in CO2-saturated 3% NaCl solution by anise extract (AE) dissolved in ethylene glycol (EG) was studied using weight loss, electrochemical and surface analysis (AFM) techniques. Inhibition efficiency increased with increase in AE concentration and temperature, reaching maximum value of 93% at 400 ppm AE concentration. Polarization results show that AE functions as a mixed-type inhibitor. Corrosion inhibition is assumed to occur by physicochemical adsorption following Langmuir adsorption isotherm model. Morphological studies of the carbon steel electrode surface undertaken by AFM confirm the adsorption of the extract on the metal surface.

Corrosion of Carbon Steel in Dense Phase CO2 with Water above and Below the Solubility Limit

Few experimental studies have addressed corrosion under dense phase CO2 transport conditions and very different corrosion rates (CR) are reported for apparently the same concentration of impurities (i.e. water) in the CO2 stream. The differences reflect short-comings in the experimental methodology and demonstration the need for a commonly agreed test approach.An experimental set up allowing accurate control of the water concentration was developed and used in the present work, which provides a more realistic condition mimicking the situation in the operating pipelines. Five corrosion experiments were conducted at 95bar to determine the corrosion rate of carbon steel in CO2 with various concentration of dissolved water. The water concentration was increased stepwise from 100 ppmv to the solubility limit and the limit was also exceeded in one of the experiment. The temperature was varied between 8°C and 35°C.The general corrosion rates determined by weight loss were around 1.0μm/y and no localised attacks were observed as long as the water content was below the solubility limit or exceeding the solubility limit with 10 percent for 400hours. The results indicate that the corrosion rate of carbon steel will be negligible in the CO2-water system as long as the water is kept below the solubility limit. The presence of other impurities than water will change the condition for precipitation of corrosive aqueous phases.

Formation of Nano-Scale FeCO<sub>3</sub> Protective Corrosion Product in Carbon Dioxide-Saturated 3% Sodium Chloride Solution

Corrosion of carbon steel in CO2 saturated NaCl solution contains the formation of FeCO3, as a corrosion product. The protective property of the formed FeCO3 scale layer to corrosion in brine solutions containing CO2 was established as the possible cause of the corrosion rate decrease above 60 °C. In this study, formation of nanoscale FeCO3 film as a corrosion product of X52 carbon steel in CO2-Saturated 3% NaCl solution was investigated. Result showed that corrosion rate decreased after precipitation and formation of protective FeCO3 film in high temperature and high bulk solution pH.

Understanding Pitting Corrosion Behaviour of X-65 Carbon Steel in CO2 Saturated Environments: The Temperature Effect

A systematic study examining the pitting corrosion behavior of X65 carbon steel (UNS K03014) in CO2-saturated 10 wt% NaCl brine is presented. This paper examines the impact of changes in a key environmental parameter (temperature) on the pitting corrosion processes of carbon steel. Pit propagation studies were conducted in static conditions at different operational temperatures. The evolution of corrosion products on carbon steel was followed over 168 h of immersion and their characteristics were related to initiation and growth of pits on the steel surface. The developed corrosion products were studied through the use of x-ray diffraction and scanning electron microscopy. The extent of pitting was evaluated through the implementation of surface interferometry to study discrete pit geometry, namely, the size and depth, while the general corrosion rate was evaluated using linear polarization resistance measurements. The results indicate that pitting corrosion dominates the general thickness loss of the mat...

Modeling Analysis of Corrosion Behavior of Carbon Steel in CO2 Loaded Amine Solutions

Modeling Analysis of Corrosion Behavior of Carbon Steel in CO2 Loaded Amine Solutions

Corrosion Inhibition by Synthesized Oleic Chains Imidazoline of Coconut in 3% NaCl Solution and CO2(g) Saturated 3% NaCl Solution

The damage caused by corrosion on the pipelines used in transport of oil brings deterioration and important economics losses, besides the irreversible social loss that comes as a consequence. The aqueous solution that flows with the oil in the pipelines as like as the 3% NaCl solution, are which give the aggressiveness to it. The presence of gases, such as CO2, increases the aggressively of the environment. The use of inhibitors of corrosion is one of the most practical methods against corrosion phenomena. This work reports the results of some traditional electrochemical techniques on the corrosion inhibition of 1018 carbon steel in CO2(g) saturated 3% NaCl solution using an inhibitor composed of oleic coconut base. The electrochemical measures shown that the corrosion rate increases during the presence of gas prevailing in the microscopic studies the suddenly surge of pitting and the typical layers of inhibitor on the surface of the material.

Corrosion of Carbon Steel in CO2 Saturated with Water and in Water Saturated with CO2

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