基于Aspen Plus工艺仿真的分馏塔顶腐蚀预测  

Predicting the Corrosion of the Fractionation Column Overhead System Based on Aspen Plus Process Simulation

作　　者：韩磊 HAN Lei(SINOPEC Research Institute of Safety Engineering Co.,Ltd.,Qingdao 266100,China)

机构地区：[1]中石化安全工程研究院有限公司,山东青岛266100

出　　处：《石油学报（石油加工）》2024年第6期1614-1623,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：中国石油化工股份有限公司项目(CLY21026)基金资助。

摘　　要：针对分馏塔顶含电解质多相体系腐蚀问题,利用Aspen Plus建立工艺仿真模型,研究了不同物性方法以及亨利组分选择对计算结果的影响,将工艺仿真结果作为铵盐结晶和酸性水腐蚀模型输入,获得塔顶水露点、pH值、NH_(4)Cl结晶温度、NH_(4)HS含量、平均流速等关键参数,构建了预测评估塔顶腐蚀的方法并开发了应用程序。利用该程序对某催化裂化装置分馏塔顶系统进行建模计算,得到塔顶水露点温度105.5℃,离子露点温度137.8℃,氯化铵结晶温度156.2℃,初凝区pH值4.77~5.60,NH_(4)HS质量分数0.72%,平均气速11.6 m/s;计算结果表明,该分馏塔顶系统存在较高的铵盐沉积腐蚀风险,而含硫污水冲蚀风险较低,为掌握塔顶腐蚀风险及调整工艺防腐操作提供了科学指导。To evaluate the multi-phase corrosion of the fractionation column overhead system,the influence of different property methods and Henry components on the gas-hydrocarbon-water phase equilibrium(VLLE)calculation results was studied using a process simulation model established by Aspen Plus.The simulation results were inputted into the ammonium salt deposition model and sour water corrosion model,so as to obtain the key parameters such as water dew point,pH value,NH_(4)Cl formation temperature,NH_(4)HS content,and average flow velocity.In such way,a method framework for comprehensively evaluating the overhead corrosion was constructed,and an application was developed based on the method framework.The modelling calculation for a fractionation column overhead system of the fluid catalytic cracking unit was carried out using the application above.Some key parameters were obtained as follows:water dew point 105.5℃,ionic dew point 137.8℃,NH_(4)Cl salt point 156.2℃,pH at first condensation 4.77—5.60,NH_(4)HS mass fraction 0.72%,and average vapor flow velocity 11.6 m/s.The results indicate that there are high risk of ammonium chloride deposition and dew point corrosion in the fractionation column overhead system but low risk of sour water erosion corrosion,which provides a guidance for understanding the corrosion risks and adjusting the anti-corrosion process operation.

关 键 词：分馏塔顶 电解质 相平衡 工艺仿真 水露点 腐蚀预测 

分 类 号：TQ050.9[化学工程] TQ013.1