渣油加氢装置原料系统腐蚀分析及对策

Corrosion of Feed System of VRDS Unit and Prevention

介绍了某公司炼油厂渣油加氢装置原料系统存在的环烷酸腐蚀问题,腐蚀主要发生在进料泵入口段及泵壳体内。该装置混合原料的硫质量分数平均为2.86%,最高3.7%,最低1.72%。混合原料的酸值为0.78 mg KOH/g。分析表明,来自第四常减压(加工胜利高硫高酸原油)的减三线和减四线的油品是造成原料酸值高的主要原因,经核算碳钢和Cr5Mo钢在苛刻环境下的腐蚀速度均超过0.2 mm/a。如果渣油加氢装置原料中的酸值超过0.5 mg KOH/g,则232℃以上的碳钢设备管道都会发生较严重的环烷酸腐蚀。通过原料调配控制酸值不超过0.5 mg KOH/g、工艺改动降低操作温度、材质升级、腐蚀监控等方法,缓解了原料系统的腐蚀问题。

As the fittings in the special railway for petrochemical facilities are in the high - temperature and water - containing environment for a long time, the fittings are subject to serious corrosion, which affects the operation of railway trains. Therefore, the corrosion protection of railway fittings has become the focus of attention of railway operation management departments of petrochemical companies. Based upon the testing comparison and analysis of service environment, corrosion mechanisms and protection measures, the protective grease with good water resistance, oxidation resistance, corrosion resistance, cohesion and easy application is selected, which has extended the service life of railway fittings, saved the costs of maintenance and improved the safe operation of trains.