The Experts below are selected from a list of 4104 Experts worldwide ranked by ideXlab platform
Srdjan Nesic - One of the best experts on this subject based on the ideXlab platform.
-
34 mathematical modeling of uniform co2 Corrosion
Trends in Oil and Gas Corrosion Research and Technologies#R##N#Production and Transmission, 2017Co-Authors: Aria Kahyarian, Mohsen Achour, Srdjan NesicAbstract:The uniform Carbon Dioxide Corrosion is one of the most widely studied subjects in Corrosion science and engineering. Numerous Corrosion rate–predictive models have been developed and reported in the literature over the past few decades. In this chapter, these models are grouped in four categories of empirical, semiempirical, elementary mechanistic, and comprehensive mechanistic, based on the mathematical methods and the calculation approach used to quantify the underlying physiochemical processes. With the focus on the mechanistic models, some key publications are reviewed, and the advantages and limits for each type of the models are discussed. Furthermore, a collection of the relevant mathematical expressions as well as solution methods required to construct the mechanistic models is provided.
-
electrochemistry of Carbon Dioxide Corrosion mitigation using tall oil diethylenetriamine imidazoline as Corrosion inhibitor for mild steel
Materials and Corrosion-werkstoffe Und Korrosion, 2016Co-Authors: Ivana Jevremovic, Marc Singer, Srdjan Nesic, V B MiskovicstankovicAbstract:The inhibition effect of tall oil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on Corrosion of mild steel in CO2-saturated 3 wt% NaCl solution was investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic sweep (PDS), cyclic voltammetry (CV), quartz crystal microbalance measurements (QCM), and scanning electron microscopy (SEM). TOFA/DETA imidazoline is a mixed-type Corrosion inhibitor with the predominant anodic effect. The results of CV measurements indicate inhibited electrode processes in the presence of TOFA/DETA imidazoline and the absence of the rapid degradation of TOFA/DETA imidazoline in the range of mild steel Corrosion potential. The Corrosion rate of mild steel significantly decreased in the presence of TOFA/DETA imidazoline, while the inhibition efficiency increased up to 92%. It was found that the adsorption of studied imidazoline compound on steel surface followed both Langmuir and Temkin adsorption isotherms. The value of molecular interaction constant calculated from Temkin adsorption isotherm implied the existence of lateral repulsion between adsorbed inhibitor molecules.
-
modeling of uniform co2 Corrosion of mild steel in gas transportation systems a review
Journal of Natural Gas Science and Engineering, 2016Co-Authors: Aria Kahyarian, Marc Singer, Srdjan NesicAbstract:Abstract The state of the art with regards the mechanistic understanding of uniform Carbon Dioxide Corrosion of mild steel is reviewed and the corresponding mathematical models are presented. The existing predictive models are categorized into three groups, termed: empirical/semi-empirical, elementary mechanistic, and comprehensive mechanistic. With emphasis on mechanistic models, selected key publications are reviewed and the limits and advantages of each group of models are discussed. Furthermore, the ability of the existing models to be extended and account for more complex Corrosion scenarios is discussed.
-
investigation of the galvanic mechanism for localized Carbon Dioxide Corrosion propagation using the artificial pit technique
Corrosion, 2010Co-Authors: Jiabin Han, Bruce Brown, Srdjan NesicAbstract:Abstract Localized Carbon Dioxide (CO2) Corrosion is the most dangerous type of internal Corrosion to mild steel pipelines in the oil and gas industry since the penetration rate of localized Corrosion can be one or more magnitudes higher than that of uniform Corrosion. In this study, the focus is on propagation of localized CO2 Corrosion on mild steel that occurs by a galvanic mechanism. A galvanic cell is established by the coupling of two distinct areas in a conductive CO2 solution: a bare steel surface and an iron Carbonate (FeCO3) layer-covered steel surface. It was found that localized CO2 Corrosion propagates when a stable difference in Corrosion potential is established between the anode (bare steel surface) and the cathode (FeCO3-covered surface). Stable propagation will occur only when the conditions are in the “gray zone,” i.e., close to saturation with respect to FeCO3, when no significant FeCO3 dissolution nor precipitation is expected. Practically, this corresponds to when FeCO3 supersaturati...
-
a mechanistic model of uniform hydrogen sulfide Carbon Dioxide Corrosion of mild steel
Corrosion, 2009Co-Authors: Srdjan NesicAbstract:Abstract A mechanistic model of uniform hydrogen sulfide (H2S) and hydrogen sulfide/Carbon Dioxide (H2S/CO2) Corrosion of mild steel is presented that is able to predict the rate of Corrosion with ...
Roland De Marco - One of the best experts on this subject based on the ideXlab platform.
-
electrochemical and surface analysis studies on the Carbon Dioxide Corrosion of x 65 Carbon steel
Electroanalysis, 2016Co-Authors: Muhammad Tanzirul Alam, Roland De Marco, Emilyn Wai Lyn Chan, Yanliang Huang, Stuart BaileyAbstract:A comprehensive study of the CO2 Corrosion of Carbon steel (X-65) at low partial pressures of CO2 is reported in this paper. Field emission scanning electron microscopy (FESEM), Raman spectroscopy (RS), synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD), and electrode kinetic studies have confirmed that chukanovite, magnetite and siderite are the main Corrosion products at low partial pressures of CO2. Chukanovite forms predominantly in the presence of CO2, while magnetite was found to be the major Corrosion product in the absence of CO2, although the majority of previous work based on conventional ex-situ materials characterization techniques has implied that siderite is the main Corrosion product. Here, it is shown that the nature of Corrosion products is strongly dependent on the experimental conditions at low pressures of CO2, which has not been elucidated in previous studies. Accordingly, this study has made a significant contribution to identifying the true nature of Corrosion scales formed at low partial pressures of CO2 allowing the development of effective anti-corrosive agents for the control and prevention of Carbon steel Corrosion at low CO2 partial pressures.
-
an in situ electrochemical impedance spectroscopy synchrotron radiation grazing incidence x ray diffraction study of the influence of acetate on the Carbon Dioxide Corrosion of mild steel
Electrochimica Acta, 2007Co-Authors: Roland De Marco, Zhongtao Jiang, Doug John, Matthew Sercombe, Brian KinsellaAbstract:A combination of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has been used to study the influence of acetate on the Carbon Dioxide Corrosion of mild steel. The SR-GIXRD data demonstrated that normal Corrosion – in a Carbon Dioxide saturated brine – induced the formation of a thick Corrosion scale of Fe2(OH)2CO3 and Fe2O2CO3, and this totally obscured the α-Fe diffraction peaks of the underlying steel substrate after 24 h. On the other hand, the Carbon Dioxide Corrosion of mild steel in the presence of acetate also detected the Bragg diffraction peaks for Fe2(OH)2CO3 and Fe2O2CO3; however, the α-Fe diffraction peaks of the underlying steel substrate were not extinguished with time, and there was a reversal in the pattern of evolution of the intensities of the Fe2(OH)2CO3 and Fe2O2CO3 phases in acetate. Accordingly, the EIS data showed a poorly defined medium frequency time constant for the corroded steel specimen in brine spiked with acetate, and this medium frequency time constant was extinguished as a function of time. Alternatively, EIS of the corroded specimen also revealed a medium frequency time constant after 24 h. In addition, EIS complex–plane impedance plots showed that the corroded electrode had become passivated in an acetate-spiked brine, as evidenced by a three-fold enhancement in the charge transfer resistance at low frequency. These EIS/SR-GIXRD outcomes suggest that acetate affects the crystallization chemistry of the Fe2(OH)2CO3/Fe2O2CO3 Corrosion scale, and this causes a mild passivation of the corroded steel surface.
-
an in situ synchrotron radiation grazing incidence x ray diffraction study of Carbon Dioxide Corrosion
Journal of The Electrochemical Society, 2005Co-Authors: Roland De Marco, Zhongtao Jiang, Bobby Pejcic, Eddy PoinenAbstract:An in situ surface study of the Carbon Dioxide Corrosion of mild steel has been undertaken using the tandem technique of mixed potential/synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD). Long-term monitoring of the mixed potential showed there was an initial shift toward cathodic potentials attributable to preferential suppression of the cathodic half-reaction (viz., the reduction of Carbonic acid), probably due to the formation of an adlayer of Corrosion product physically blocking the cathodic reaction sites during the uniform Corrosion of mild steel. Subsequently, the mixed potential displayed a gradual shift to anodic potentials, symbolizing the preferential suppression of the anodic half-reaction as the primary Corrosion products [viz., Fe2(OH)2CO3, Fe2O2(CO3), Fe6(OH)12(CO3), and Fe6(OH)12(CO3)·2H2O] acquired a sufficient thickness to physically block the interface against further Corrosion. Nevertheless, the Corrosion product continues to grow over time, indicating that the Corrosion product is discontinuous and porous, allowing the ingression of electrolyte to enable the further Corrosion of the mild steel. This research has important ramifications for the field of Corrosion research; it should enable researchers to develop improved methods of chemical inhibition by using compounds that can actually bind to the newly postulated Corrosion products on mild steel.
Brian Kinsella - One of the best experts on this subject based on the ideXlab platform.
-
an in situ electrochemical impedance spectroscopy synchrotron radiation grazing incidence x ray diffraction study of the influence of acetate on the Carbon Dioxide Corrosion of mild steel
Electrochimica Acta, 2007Co-Authors: Roland De Marco, Zhongtao Jiang, Doug John, Matthew Sercombe, Brian KinsellaAbstract:A combination of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has been used to study the influence of acetate on the Carbon Dioxide Corrosion of mild steel. The SR-GIXRD data demonstrated that normal Corrosion – in a Carbon Dioxide saturated brine – induced the formation of a thick Corrosion scale of Fe2(OH)2CO3 and Fe2O2CO3, and this totally obscured the α-Fe diffraction peaks of the underlying steel substrate after 24 h. On the other hand, the Carbon Dioxide Corrosion of mild steel in the presence of acetate also detected the Bragg diffraction peaks for Fe2(OH)2CO3 and Fe2O2CO3; however, the α-Fe diffraction peaks of the underlying steel substrate were not extinguished with time, and there was a reversal in the pattern of evolution of the intensities of the Fe2(OH)2CO3 and Fe2O2CO3 phases in acetate. Accordingly, the EIS data showed a poorly defined medium frequency time constant for the corroded steel specimen in brine spiked with acetate, and this medium frequency time constant was extinguished as a function of time. Alternatively, EIS of the corroded specimen also revealed a medium frequency time constant after 24 h. In addition, EIS complex–plane impedance plots showed that the corroded electrode had become passivated in an acetate-spiked brine, as evidenced by a three-fold enhancement in the charge transfer resistance at low frequency. These EIS/SR-GIXRD outcomes suggest that acetate affects the crystallization chemistry of the Fe2(OH)2CO3/Fe2O2CO3 Corrosion scale, and this causes a mild passivation of the corroded steel surface.
-
a study of the adsorption properties of commercial Carbon Dioxide Corrosion inhibitor formulations
Journal of Applied Electrochemistry, 2001Co-Authors: W Durnie, Brian Kinsella, R De Marco, Alan JeffersonAbstract:Corrosion rate data for several commercial Carbon Dioxide Corrosion inhibitors have been fitted to the Temkin adsorption isotherm and van't Hoff equation, enabling a determination of the enthalpy of adsorption (ΔHad∘). It has been found that experimentally determined ΔHad∘ values for commercial inhibitor formulations can provide valuable insights into the behaviour of the inherent active components. The temperature sensitivities along with the mechanism of adsorption (physi- or chemisorption) and the minimum concentration required for activity of inhibitors is determinable by this approach. Additionally, FTIR has been used to identify those inhibitors that are tenaciously adsorbed to steel, and suitable for use in batch treatment applications.
-
mapping non uniform Corrosion using the wire beam electrode method i multi phase Carbon Dioxide Corrosion
Corrosion Science, 2001Co-Authors: Stuart Bailey, Brian KinsellaAbstract:Abstract A wire beam electrode (WBE) was used in conjunction with electrochemical noise resistance (Rn) measurements to map Carbon Dioxide Corrosion of steel (UNS no. G10350) under simulated multi-phase oil flowline conditions. Local electrochemical parameters including Corrosion potential, galvanic current and electrochemical noise resistance were successfully measured from corroding WBE surfaces exposed to highly resistive hydroCarbon/produced water mixtures. These electrochemical parameters were used to calculate the rates of localised Corrosion and their distribution over a WBE surface. Electrochemically ‘calculated’ Corrosion maps correlated clearly with microscopically ‘observed’ Corrosion depth maps although this correlation was not perfect and requires further improvement. This work suggests that the combined WBE–Rn technique is capable of measuring Carbon Dioxide Corrosion under multi-phase conditions and that it has certain advantages over conventional electrochemical measurements for measuring Corrosion in highly resistive media.
-
electrochemical impedance spectroscopy and surface characterization techniques to study Carbon Dioxide Corrosion product scales
Corrosion, 1998Co-Authors: Brian Kinsella, Stuart BaileyAbstract:Abstract Electrochemical impedance spectroscopy (EIS) was used to study Carbon Dioxide (CO2) Corrosion product scales and their effects on further CO2 Corrosion. Objectives were to determine the suitability of EIS for studying Corrosion scales and to investigate the influence of environmental factors on scale formation. EIS provided useful information about protective abilities and electrochemical properties of Corrosion scales. CO2 Corrosion scales formed at high-temperature and pressure provided better protection than those formed at low-temperature and pressure. The level of protection of the scale formed at higher temperature and pressure increased with exposure time. EIS results were compared with coupon weight-loss measurements. Scales were analyzed using a combination of Fourier transform infrared (FTIR) analysis, x-ray diffraction (XRD), and electron microscopy.
Xudong Yang - One of the best experts on this subject based on the ideXlab platform.
-
eis study of the surface film on the surface of Carbon steel from supercritical Carbon Dioxide Corrosion
Applied Surface Science, 2004Co-Authors: Zhenduo Cui, Shengli Zhu, G X Zhao, M L Yan, Xudong YangAbstract:The electrochemical impedance spectroscopy (EIS) technique was used to investigate the characteristics of the surface film on the surface of Carbon steel formed in static simulated produced water saturated with supercritical Carbon Dioxide (SC-CO2). Electrical equivalent circuits were proposed to describe the electrochemical behavior. The results showed that a protective surface film was observed on the surface of the pre-filmed samples. In general, the protective performance of the surface film was enhanced with the increase of the exposure time within the time period of 0‐6 h. The surface film formed at a high temperature was more protective than that formed at a low temperature because the fast formation of the film at elevated temperatures and the surface film became more compact and continuous with the increase of the temperature. Results of EIS were in good agreement with the weight-loss measurements. # 2004 Elsevier B.V. All rights reserved. PACS: 82.45
-
characterization of the surface film formed from Carbon Dioxide Corrosion on n80 steel
Materials Letters, 2004Co-Authors: Zhenduo Cui, Z Q Bai, Shengli Zhu, Xudong YangAbstract:Abstract X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to systematically characterize the chemical composition and the microstructure of the surface film on N80 oil tube steel exposed to Carbon Dioxide (CO2) Corrosion. A crack-free laminar surface film was observed on the N80 oil tube steel under turbulent flow condition for 72 h at 80 °C with a Carbon Dioxide partial pressure of 0.5 MPa. The surface film was composed mainly of a complex Carbonate (Fe, Ca)CO3 and of a limited amount of α-FeOOH. The complex Carbonate produced under the condition of this study was unstable and partially decomposed into α-FeOOH in desiccated air. The extending of the Corrosion testing time and the formation of complex Carbonate both contributed to the enhanced stability of the surface film.
O G Sinyashin - One of the best experts on this subject based on the ideXlab platform.
-
New, effective Carbon Dioxide and hydrogen sulfide Corrosion inhibitors based on white phosphorus, sulfur, alcohols, and amines
Petroleum Chemistry, 2013Co-Authors: Elvira S. Batyeva, Elena V. Platova, Yu. P. Khodyrev, E K Badeeva, O. V. Ugryumov, O. A. Varnavskaya, S. I. Vasyukov, O G SinyashinAbstract:New ammonium salts of dithiophosphoric O , O ′-diesters have been obtained by simple and convenient (one pot) methods of synthesis from white phosphorus (P4), elemental sulfur, alcohols, phenols (including hydroxyethylated nonylphenols), and amines. It has been revealed that the ammonium salts of O , O -dialkyl dithiophosphoric acids obtained are effective inhibitors of Carbon Dioxide Corrosion (protective effect Z = 90–99%) and hydrogen sulfide Corrosion ( Z = 88–89%) of a mild steel. It has been shown that the inhibitory activity against Carbon Dioxide Corrosion depends on neither theamine nature nor the chain length of the alkyl substituent in the ester group and the protective effect in the case of hydrogen sulfide Corrosion depends on the nature of the reactant alcohol or amine and may slightly decrease (by 10–15%). An advantage of these inhibitors is that their protective effect in Carbon Dioxide Corrosion is enhanced with temperature (30–80°C), rather than decreases.
-
new method for the synthesis of ammonium salts of o o dialkyldithiophosphoric acids on the basis of elemental phosphorus and sulfur a method for the preparation of effective inhibitors for Carbon Dioxide Corrosion of mild steel
Phosphorus Sulfur and Silicon and The Related Elements, 2011Co-Authors: O G Sinyashin, Elena V. Platova, Elvira S. Batyeva, Yury P Khodyrev, еlena K Badeeva, Lidiya I. KurshevaAbstract:Abstract New ammonium salts of O,O′-dialkyldithiophosphoric acids have been obtained based by the reaction of white phosphorus (P4)–alcohol–amine–elemental sulfur. The reaction is characterized by full conversion of white phosphorus and is not accompanied by the release of hydrogen sulfide. It has been established that all studied compounds are highly efficient inhibitors of CO2-mediated Corrosion of mild steel active at concentrations of 0.25–5 mg·L−1.
-
the inhibition action of ammonium salts of o o dialkyldithiophosphoric acid on Carbon Dioxide Corrosion of mild steel
Corrosion Science, 2011Co-Authors: Yu. P. Khodyrev, Elena V. Platova, Elvira S. Batyeva, L. Tiwari, E K Badeeva, O G SinyashinAbstract:Abstract Ammonium salts of O,O′-dialkyldithiophosphoric acids (RО)2 Р(S) S− HN+ R ′ R 2 ″ , were synthesized and tested as inhibitors for Carbon Dioxide Corrosion of mild steel using weight loss, polarization curves, electrochemical impedance spectroscopy and scanning electron microscopy methods. High inhibition efficiency has been found for all compounds (η = 70–99%) at very low concentrations (0.25–5) mg l−1. Polarization curves show that the title compounds can be considered as inhibitors of the mixed type. The absorption of inhibitor molecules on the mild steel surface obeys the Langmuir isotherm. Inhibition efficiency for some ammonium salts increases with temperature. The activation energy and some thermodynamic parameters were computed.