关键词: 高酸原油, 常压塔, 挥发线, 腐蚀速率, 含硫污水, 有机酸, 气相流速, 中和剂

Abstract:

This study focuses on the serious corrosion problem faced by the overhead line of a certain atmospheric distillation tower top (overhead) for processing high acid crude oil. The online corrosion monitoring data of the overhead line has exceeded the control indicators for a long time, and many corrosion pits and thinning areas were found during the inspection, posing a risk of corrosion leakage. By analyzing the fixed-point thickness measurement, probe corrosion rate, probe corrosion scale, and corrosive medium of overhead sulfur-containing wastewater, combined with the calculation of the medium flow rate in the overhead line, two main factors that exacerbate the corrosion process are identified: the presence of a high concentration (390-600mg/L) of various small molecular organic acids in the overhead line medium, and the high flow rate of the medium at the top of the tower. Two targeted measures have been taken to address the corrosion issue of the overhead line: controlling the flow rate of naphtha at the top of the tower to not exceed 150t/h to reduce the accumulation of corrosive media in the system; optimizing the selection of neutralizing agents to ensure that they can effectively neutralize acidic substances in the system, thereby significantly reducing the corrosion rate. The implementation of these measures has improved the corrosion condition of the overhead line, extended the service life of the equipment, and ensured the long-term, stable, and safe operation of the unit.

Key words: high acid crude oil, atmospheric distillation tower, vapor line, corrosion rate, sulfur-containing wastewater, organic acid, gas phase flow rate, neutralizing agent