安全、健康和环境

随着原油劣质化加剧及装置长周期运行要求提高，炼油装置腐蚀问题日益突出。某炼化公司1.8×10⁶ t/a连续重整装置运行中，在线腐蚀监测发现脱异戊烷塔顶及回流系统存在壁厚异常现象。为评估腐蚀失效风险并防范潜在事故，2024年装置停工检修期间开展了腐蚀调查与风险分析，发现预分馏系统多处设备及管线存在严重腐蚀。采用宏观腐蚀形貌检验、腐蚀产物能谱分析及装置第一个运行周期工艺运行环境分析等方法进行系统分析。结果表明，腐蚀主要由原料中轻质硫化物含量高、未设缓冲罐导致原料含水较多，以及先分馏后加氢的工艺共同作用形成的严重湿硫化氢环境所致。针对分析评估结果，提出增设原料缓冲罐、材质升级和工艺控制等对策。措施实施一年内，脱异戊烷塔顶回流罐及其出口管线最大减薄部位的腐蚀速率由0.92 mm/a显著降低至0.09 mm/a(降幅约90%)。本研究通过系统风险识别与评估，提出了针对性的防控措施，为类似装置的事故预防与安全运行提供了参考。

With the deterioration of crude oil quality and increasing demands for long-term operational reliability of refinery facilities, corrosion issues of oil refining units have become increasingly prominent. During the operation of the 1.8×10⁶ t/a continuous reforming unit at a certain refining and chemical company, online corrosion monitoring detected abnormal wall thickness at the top of the isopentane tower and in the reflux system. To assess the risk of corrosion failure and prevent potential accidents, a corrosion investigation and risk analysis were carried out during the shutdown and maintenance in 2024. The inspection revealed severe corrosion in multiple pieces of equipment and pipelines within the pre-fractionation system. The system was analyzed by means of macroscopic corrosion morphology inspection, energy spectrum analysis of corrosion products, and analysis of the process operating conditions in the first operation cycle of the equipment. The corrosion was mainly caused by a severe wet hydrogen sulfide environment, which resulted from the combined effect of high levels of light sulfides in the feedstock, elevated water content due to the absence of a buffer tank, and the process configuration of fractionation followed by hydrotreating. Targeted countermeasures were proposed including the installation of raw material buffer tanks, material upgrading and enhanced process control. Within one year of implementation these measures, the corrosion rate at the maximum thinning part of the reflux tank at the top of the isopentane tower and its outlet pipeline was significantly reduced from 0.92 mm/a to 0.09 mm/a(a reduction of approximately 90%). Through systematic risk identification and assessment, this study proposes targeted prevention and control measures, providing an important reference for the accident prevention and safe operation of similar devices.