碳钢和不锈钢在二氧化碳捕集封存与利用装置中现场挂片腐蚀性能研究

Study on Corrosion Property of On-Site Hanging Coupon of Carbon Steel and Stainless Steel in Carbon Dioxide Capture,Utilization and Storage Devices

为了研究二氧化碳捕集封存与利用(CCUS)中碳捕集单元用材料的耐腐蚀性,选用Q355、304L和316L 3种金属材料,在火电厂胺法碳捕集单元和烟囱中的8个典型位置进行现场腐蚀挂片试验,采用失重法计算3种材料在8个测试点的腐蚀速率,观察腐蚀后的宏观和微观形貌,用X射线衍射(XRD)分析Q355表面腐蚀产物。结果表明:304L在烟囱内会发生露点腐蚀和点蚀;304L和316L在胺法碳捕集单元中腐蚀速率很低,无点蚀发生,可作为胺法碳捕集装置的选材;Q355胺法碳捕集单元中,液相的腐蚀性整体高于气相的腐蚀性,低温富胺液的腐蚀性强于低温和高温贫胺液的腐蚀性,在富胺液中的腐蚀产物以FeO(OH)为主,在贫胺液中生成的腐蚀产物以Fe_(3)O_(4)为主。

In order to investigate the corrosion resistance of the materials used in the carbon capture unit of carbon dioxide capture,utilization and storage(CCUS)application,three kinds of metal materials,Q355,304L and 316L,were selected to carry out on-site corrosion hanging coupon test in eight typical locations of amine carbon capture unit and chimney in thermal power plant.The corrosion rates of the three materials at eight test points were calculated by weight loss method.The macroscopic and microscopic morphology after corrosion was observed,and the surface corrosion products of Q355 were analyzed by X-ray diffraction(XRD).Results showed that dew point corrosion and pitting corrosion of 304L could occur in chimney.The corrosion rates of 304L and 316L in the amine carbon capture unit were very low and no pitting corrosion oc-curred,which could be used as the material of the amine carbon capture device.In the process of amine carbon capture unit of Q355,the cor-rosiveness of liquid phase was higher than that of gas phase,and the corrosiveness of low temperature amine-rich solution was stronger than that of low temperature and high temperature amine-poor solution.The corrosion products in amine-rich solution were mainly FeO(OH),and the corrosion products generated in amine-poor solution were mainly Fe_(3)O_(4).