Analysis on the corrosion characteristic and risk in atmospheric tower using Aspen plus software

Abstract

The corrosion problem of atmospheric tower, as the main distillation unit in refineries, has attracted much researchers’ attention. Based on the Braun K-10 thermodynamic model and Peng-Robinson equation, the process simulation was performed to predict the corrosion risk in the atmospheric tower. The distributions of the temperature, phase state and corrosive components in the multi-component stream were analyzed. The results have shown that the temperature distribution in the atmospheric tower is linearly correlated with the processing capacity and the properties of raw materials. The feed with corrosive medium can reduce the tower temperature by 15 °C on average. In addition, it has been found that both of the ammonium salt under-deposited corrosion and dew point corrosion exist in the atmospheric tower. The initial crystallization temperature of ammonium salt is located at the 15th stage of tray, and the dew point corrosion region is among the 1st and 15th stage of tray. The prediction results of the high-risk corrosion areas are coincided to the actual corrosion regions.