CCUS超临界/密相CO_(2)管道内腐蚀研究进展

Research progress on internal corrosion of supercritical/dense-phase CO_(2) pipelines for CCUS

[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CO_(2)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CO_(2)管道安全的关键问题。[方法]围绕超临界CO_(2)为主相的腐蚀展开调研,综述了超临界/密相CO_(2)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CO_(2)管道腐蚀的影响因素,阐述了温度、压力等工作参数对水与CO_(2)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CO_(2)管道内腐蚀的影响机制,分析了在不同的CO_(2)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CO_(2)环境下的腐蚀特性表征技术,总结了适用于薄液膜超临界CO_(2)环境的腐蚀速率预测模型。[结论]要实现CO_(2)输送管道的安全平稳运行,目前超临界-密相CO_(2)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CO_(2)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CO_(2)腐蚀预测模型建立。

[Objective]Carbon Capture,Utilization and Storage(CCUS)is an effective approach for achieving“carbon peaking and carbon neutrality”,with promising application prospects.Long-distance CO_(2) 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 CO_(2) environments,reviewed research outcomes on internal corrosion of supercritical/dense-phase CO_(2) pipelines,analyzed problems existing in the research outcomes,and outlined future development directions.[Results]The factors influencing CO_(2) pipeline corrosion in supercritical and dense-phase states were discussed,highlighting the impact of key parameters like temperature and pressure on water-CO_(2) solubility.Reasons for conflicting research outcomes were addressed,along with the influence mechanism of main impurity gases in the pipelines on CO_(2) 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 CO_(2) phase states.Finally,the study identified suitable corrosion characterization techniques for supercritical CO_(2) environments and collated corrosion rate prediction models for thin liquid films in these environments.[Conclusion]To ensure the safe and stable operation of CO_(2) transportation pipelines,current corrosion research challenges for supercritical/dense-phase CO_(2) 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 watersaturated CO_(2) phase;and developing a prediction model for supercritical/dense-phase CO_(2) corrosion considering coupled multi-impurity interactions.