Abstract:

For CCR unit that employ dry cooling cycles for catalyst regeneration, regenerative recycle gas drying is an indispensable system in continuous catalytic reformers. In recent years, corrosion and leakage problems have occurred many times, which seriously affects the long-term operation of the unit. An analysis was conducted on the corrosion causes of the internal coolers, separators and connecting pipelines in the regeneration cycle gas drying system of four continuous reforming units. It was found that the main causes of corrosion were acidic gas dew point corrosion and circulating water corrosion. In response to the current corrosion situation, a series of control measures to extend the operating cycle are proposed in the following text. Increasing the inclination angle for the installation of the inlet and outlet of the heat exchanger shell in the process design, and adding filters. Add fiberglass or PTFE lining to the separator and connecting pipes in the material selection, and add coating anti-corrosion to the carbon steel pipe bundle of the water cooler; Control the quality of circulating water in operation, strengthen monitoring of process parameters and corrosion conditions.

Key words: CCR unit, regeneration recycle, gas dryer, corrosion, cooler, separator, gas inlet pipeline

摘要：

对于催化剂再生采用干冷循环的连续重整技术，再生循环气干燥是连续重整装置中不可或缺的系统，近年来多次发生腐蚀泄漏问题，严重影响装置的长周期运行。针对4个连续重整装置再生循环气干燥系统发生的腐蚀案例，分析了系统内冷却器、分离器以及相连管道的腐蚀原因。结果发现腐蚀原因主要是酸性气露点腐蚀和循环水腐蚀。针对腐蚀现状，提出了一系列延长操作周期的控制措施：工艺设计上增加换热器壳程进出口安装倾斜角度，增加过滤器；选材上分离器及相连管道增加玻璃钢或PTFE(聚四氟乙烯)衬里，水冷器碳钢管束增加涂层防腐；操作上控制循环水水质，加强工艺参数和腐蚀情况监测。

关键词: 连续重整装置, 再生循环气, 干燥系统, 腐蚀, 冷却器, 分离器, 气体入口管线