The Discussion on Corrosion and Prevention in the Overhead System of the Vacuum Tower

Abstract In the petrochemical industry, corrosion of the top head of the atmospheric /vacuum tower is always a big issue that greatly sparked safe and economic events. Even though much research has been undertaken, the corrosion problem has never been addressed. Moreover, less attention has been paid to the vacuum tower overhead systems. The oil and gas components and process conditions of the top head of atmospheric/vacuum towers determine that ammonium chloride, amine hydrochloride corrosion, and hydrochloric acid corrosion is generally the dominant corrosion mechanisms. The challenges of controlling corrosion of the atmospheric and vacuum tower overhead systems are vast and different in some aspects. While the corrosion control measures for the atmospheric tower overheads can also be used for the vacuum tower, the effectiveness and efficiency must be justified. This paper analyses the main corrosion factors in the overheads of the atmospheric tower and vacuum tower. A typical corrosion case on the top head of a vacuum tower is discussed and explored, after which the optimisation of the corrosion control measures is proposed.