Corrosion Causes and Countermeasures for Solvent Drying Department in Solvent De-waxing

In order to solve the problem of severe corrosion existing in the solvent drying department in the solvent de-waxing unit of Taizhou Petrochemical Corporation, the corrosion reasons were analyzed. It is considered that the corrosion was caused by two problems: one was the special chemical structure and strong corrosiveness of naphthenic acid in the feedstock; another was the high water content in solvent. It was also found that certain special naphthenic acids in the feedstock caused significant corrosion for carbon steel in the presence of water at around 100 ℃. Recycled solvent water content was reduced by a series of optimization operations, and thus alleviating the corrosion of solvent recovery system and good results had been achieved.