环烷酸对减压塔顶空冷器腐蚀的影响及对策  

Naphthenic Acid's Corrosion on Vacuum Tower Overhead Air Cooler and Countermeasures

作　　者：张崇林[1] 丁明生[1] 

机构地区：[1]中国石化扬子石油化工股份有限公司,江苏南京210048

出　　处：《石油化工腐蚀与防护》2012年第2期34-37,共4页Corrosion & Protection In Petrochemical Industry

摘　　要：通过分析减压塔塔顶空冷器腐蚀特点,发现减压塔顶空冷器腐蚀非常快,减顶切水铁离子质量分数随时间大幅上升。确定了减压塔顶空冷器腐蚀加剧的主要原因是加工原油的劣质化,特别是高酸原油。环烷酸是造成常减压高温部位腐蚀的主要原因。结果表明,当减压塔塔顶温度超过120℃时,部分小分子环烷酸以及由环烷酸分解产生的小分子羧酸进入塔顶冷凝冷却系统,加剧了空冷器的腐蚀。通过降低减压塔塔顶温度,调整工艺防腐蚀措施,减压塔塔顶切水铁离子质量分数降至3 mg/L以下,塔顶空冷器的腐蚀得到有效的控制,换热器、管线等腐蚀明显降低。The analysis of corrosion in vacuum tower overhead air coolers has concluded that the main causes of accelerated corrosion in air coolers is the processing of low-quality crude oil,especially the high-TAN crude oil.Whereas the naphthenic acid is the culprit of corrosion in the high-temperature section of atmospheric-vacuum distillation unit.When the vacuum tower overhead temperature exceeds 120 ℃,part of naphthenic acid of small molecules and carboxylic acid of small molecules from decomposition of naphthenic acid entered the overhead condensing cooling system and the corrosion of air cooler is accelerated.The corrosion in overhead air cooler has been brought under control and the corrosions of heat exchangers and pipelines have been obviously reduced by lowering the vacuum tower overhead temperature,application of effective process corrosion prevention methods and reduction of Fe ions in overhead water to lower than 3 mg/L.

关 键 词：常减压 减顶 环烷酸 腐蚀 缓蚀剂 

分 类 号：TE965[石油与天然气工程—石油机械设备]