Research progress on internal corrosion of supercritical/dense-phase CO2 pipelines for CCUS
LIU Guangyu1,ZHI Shujie2,LIU Xin3,CHAI Chong2,WANG Cailin1,YU Xinran1,HU Qihui1,RAO Shiduo1

1.College of Pipeline and Civil Engineering, China University of Petroleum (East China)//Shandong Key Laboratory of Oil & Gas Storage and Transportation Safety; 2.PipeChina Institute of Science and Technology; 3.CNOOC Research Institute Co. Ltd.

CCUS, supercritical CO2, dense-phase CO2, corrosion, CPF

DOI: 10.6047/j.issn.1000-8241.2024.05.004


【目的】碳捕集、利用与封存(Carbon Capture, Utilization and Storage, CCUS)技术是实现双碳战略的有效途径,具有广阔的应用前景。长距离CO2管道输送是CCUS技术的重要一环,对于管道安全生产运行而言,管道内腐蚀是威胁CO2管道安全的关键问题。【方法】围绕超临界CO2为主相的腐蚀展开调研,综述了超临界/密相CO2管道内腐蚀的研究成果,分析了相关研究成果之间存在的问题,并展望了其未来发展方向。【结果】重点介绍了超临界态和密相态下CO2管道腐蚀的影响因素,阐述了温度、压力等工作参数对水与CO2互溶程度的影响,解释了目前现有研究成果存在相互矛盾结果的原因,归纳了主要杂质气体对CO2管道内腐蚀的影响机制,分析了在不同的CO2相态下,腐蚀产物膜的结构、密度及完整性对腐蚀动力学的影响,整理了适用于超临界CO2环境下的腐蚀特性表征技术,总结了适用于薄液膜超临界CO2环境的腐蚀速率预测模型。【结论】要实现CO2输送管道的安全平稳运行,目前超临界-密相CO2输送管道腐蚀研究有待解决的问题包括:标准实验流程的建立;杂质耦合作用对腐蚀机理和腐蚀产物膜结构的影响;定量描述腐蚀产物膜的特性对基体的保护作用;水饱和CO2相中薄液膜环境下的腐蚀电化学参数测量与分析;耦合多杂质相互作用下的超临界/密相CO2腐蚀预测模型建立。(图2表2,参[108]
[Objective] Carbon Capture, Utilization and Storage (CCUS) is an effective approach for achieving “carbon peaking and carbon neutrality”, with promising application prospects. Long-distance CO2 pipeline transportation is a critical component of CCUS. Addressing internal corrosion in pipelines is a key safety concern that must be handled effectively to ensure the safe production and operation of these pipelines. [Methods] The study examined pipeline corrosion in supercritical CO2 environments, reviewed research outcomes on internal corrosion of supercritical/dense-phase CO2 pipelines, analyzed problems existing in the research outcomes, and outlined future development directions. [Results] The factors influencing CO2 pipeline corrosion in supercritical and dense-phase states were discussed, highlighting the impact of key parameters like temperature and pressure on water-CO2 solubility. Reasons for conflicting research outcomes were addressed, along with the influence mechanism of main impurity gases in the pipelines on CO2 corrosion. Additionally, an analysis was conducted on the effects of the structure, density and integrity of the corrosion product films (CPFs) on corrosion dynamics under varying CO2 phase states. Finally, the study identified suitable corrosion characterization techniques for supercritical CO2 environments and collated corrosion rate prediction models for thin liquid films in these environments. [Conclusion] To ensure the safe and stable operation of CO2 transportation pipelines, current corrosion research challenges for supercritical/dense-phase CO2 pipelines include: standardizing experimental procedures;studying the impact of impurity coupling on corrosion mechanisms and CPF structures; quantifying the protective effects of CPF characteristics on the substrate; measuring and analyzing electrochemical corrosion parameters in thin liquid film environments within water-saturated CO2 phase; and developing a prediction model for supercritical/dense-phase CO2 corrosion considering coupled multi-impurity interactions. (2 Figures, 2 Tables, 108 References)