{"title":"Investigation of supercritical CO2 corrosion behavior of X80 carbon steel in pipelines: An in situ experimental and DFT study","authors":"","doi":"10.1016/j.supflu.2024.106371","DOIUrl":null,"url":null,"abstract":"<div><p>The electrochemical corrosion behavior of X80 carbon steel was investigated in a supercritical CO<sub>2</sub> (sCO<sub>2</sub>) environment at 60 ℃ and 9 MPa, by in-situ experiments and density functional theory (DFT) calculations, revealing the corrosion mechanism. For in situ electrochemical measurements, two novel CO<sub>2</sub>-rich and H<sub>2</sub>O-rich cells were developed to replace the traditional three-electrode cell. Electrochemical impedance spectroscopy revealed distinct differences in the corrosion behavior between CO<sub>2</sub>-rich and H<sub>2</sub>O-rich environments during the later stages of testing. In H<sub>2</sub>O-rich environments, as corrosion time increased, the corrosion product layer gradually changed from porous to dense, eventually forming a protective layer. In CO<sub>2</sub>-rich environments, corrosion occurs mainly in areas where water condenses to form FeCO<sub>3</sub>. Simultaneously, microscopic calculations provided evidence for the three-step sCO<sub>2</sub> hydrolysis mechanism and the formation of FeCO<sub>3</sub> products.</p></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":null,"pages":null},"PeriodicalIF":3.4000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Supercritical Fluids","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0896844624002067","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The electrochemical corrosion behavior of X80 carbon steel was investigated in a supercritical CO2 (sCO2) environment at 60 ℃ and 9 MPa, by in-situ experiments and density functional theory (DFT) calculations, revealing the corrosion mechanism. For in situ electrochemical measurements, two novel CO2-rich and H2O-rich cells were developed to replace the traditional three-electrode cell. Electrochemical impedance spectroscopy revealed distinct differences in the corrosion behavior between CO2-rich and H2O-rich environments during the later stages of testing. In H2O-rich environments, as corrosion time increased, the corrosion product layer gradually changed from porous to dense, eventually forming a protective layer. In CO2-rich environments, corrosion occurs mainly in areas where water condenses to form FeCO3. Simultaneously, microscopic calculations provided evidence for the three-step sCO2 hydrolysis mechanism and the formation of FeCO3 products.
通过原位实验和密度泛函理论(DFT)计算,研究了 X80 碳钢在 60 ℃ 和 9 MPa 的超临界 CO(sCO)环境中的电化学腐蚀行为,揭示了腐蚀机理。为进行原位电化学测量,开发了两种新型富含 CO 和 HO 的电池,以取代传统的三电极电池。电化学阻抗光谱显示,在测试的后期阶段,富含 CO 和富含 HO 环境中的腐蚀行为存在明显差异。在富含 HO 的环境中,随着腐蚀时间的延长,腐蚀产物层逐渐从多孔变为致密,最终形成保护层。在富含 CO 的环境中,腐蚀主要发生在水冷凝形成 FeCO 的区域。同时,微观计算为三步 sCO 水解机制和 FeCO 产物的形成提供了证据。
期刊介绍:
The Journal of Supercritical Fluids is an international journal devoted to the fundamental and applied aspects of supercritical fluids and processes. Its aim is to provide a focused platform for academic and industrial researchers to report their findings and to have ready access to the advances in this rapidly growing field. Its coverage is multidisciplinary and includes both basic and applied topics.
Thermodynamics and phase equilibria, reaction kinetics and rate processes, thermal and transport properties, and all topics related to processing such as separations (extraction, fractionation, purification, chromatography) nucleation and impregnation are within the scope. Accounts of specific engineering applications such as those encountered in food, fuel, natural products, minerals, pharmaceuticals and polymer industries are included. Topics related to high pressure equipment design, analytical techniques, sensors, and process control methodologies are also within the scope of the journal.