NH_(3)-HCl-H_(2)S环境下酸性水汽提装置流动腐蚀特性评估  

Evaluation of Flow Corrosion Characteristics of Acid Water Stripping Device in NH_(3)-HCl-H_(2)S Environment

作　　者：偶国富 陈冠宇 Ou Guofu;Chen Guanyu(School of Environment Science and Engineering,Changzhou University,Changzhou,Jiangsu 213000,China)

机构地区：[1]常州大学环境科学与工程学院,江苏常州213000

出　　处：《化工设备与管道》2023年第2期39-47,共9页Process Equipment & Piping

基　　金：国家自然科学基金-重点项目(U19092016);国家自然科学基金-面上项目(51876194、U1261124、50976106、20576125)。

摘　　要：酸性水汽提装置的塔盘和塔壁是易发生氯化铵结晶腐蚀和垢下腐蚀的高风险区域,严重影响装置安全可靠长期的稳定运行。针对某石化企业酸性水汽提塔中的塔盘及塔壁腐蚀减薄穿孔问题,基于PR(Peng-Robinson)状态方程和电离方程,采用Aspen Plus工艺模拟软件对酸性水汽提装置内多组分流体的流动腐蚀机理进行研究,分析汽提塔内部腐蚀性介质在各塔板数中的分布变化,并构建了铵盐结晶沉积腐蚀、垢下腐蚀相适应的预测评估模型,同时采用NRTL电解质模型分析液相中各离子浓度分布规律。研究结果表明:在第7、8、9层塔盘存在铵盐结晶,NH_(4)Cl初始结晶温度为42.73℃,铵盐结晶量约为7.10×10^(-49) kmol/h,在进料段以上塔段的NH_(4)HS浓度约为6%左右,具有一定流动腐蚀性,且NH3富集位置在第25层塔盘,汽提装置顶部存在一定的减薄和穿孔泄漏风险,计算结果与实际检修结果有较好的吻合性。The tray and wall of sour water stripping unit are high-risk areas prone to ammonium chloride crystallization corrosion and corrosion under scale,which seriously affect the safe,reliable and long-term stable operation of the unit.Aiming at the problem of corrosion,thinning and perforation of tray and tower wall in the sour water stripper of a petrochemical enterprise,Based on the PR(Peng-Robinson)equation of state and ionization equation,Aspen Plus process simulation software was used to study the flow and corrosion mechanism of multi-component fluids in the acidic water stripping tower of a petrochemical enterprise.The distribution changes of corrosive media inside the stripping tower in each plate number were analyzed,and the ammonium salt crystallization deposition corrosion model was constructed.At the same time,the NRTL electrolyte model was used to analyze the concentration distribution of ions in the liquid phase.The results show that ammonium salt crystals exist in the 7th,8th and 9th trays.The initial crystallization temperature of NH_(4)Cl is 42.73℃,and the amount of ammonium salt crystallization is about 7.10×10^(-49) kmol/h,the NH_(4)HS concentration in the tower section above the feed section is about 6%,which has a certain flow corrosivity,and the NH3 enrichment location is in the 25th tower tray,and there is a certain risk of thinning and perforation leakage at the top of the stripping device.The calculated results are in good agreement with the actual maintenance results.

关 键 词：汽提装置 流动腐蚀 Aspen Plus建模 预测评估 

分 类 号：TE986[石油与天然气工程—石油机械设备]