Corrosion Mechanism and Protective Measures of Overhead System of Atmospheric and Vacuum Distillation Unit

The corrosion cases of overhead system of atmospheric and vacuum distillation unit were sorted out, and the main types of corrosion of the overhead system:dew point corrosion and ammonium salt corrosion, were introduced. Multiphase equilibrium system calculation method was used to obtain the dew point temperature at the overhead. The regular characteristics of dew point corrosion were deeply understood, and effective anti-corrosion measures such as ammonia injection (amine) and water injection were proposed. According to the specific process parameters in the case, the equilibrium curves and calculation formula of ammonium salt were obtained by solving the thermodynamic equation. The crystallization tendency and temperature range of ammonium salt were determined, and the regularity of ammonium salt corrosion was discussed in depth.