Naphthenic Acid Corrosion

Naphthenic acid corrosion is not a new problem for refiners. Over 45 years ago, it was identified as potentially troublesome in U.S. refineries that processed unusually acidic crudes (1). By 1956, Derungs had outlined the crude characteristics and processing conditions that favor naphthenic acid corrosion and had suggested ways to minimize such damage in distillation towers, which he identified as the most susceptible units (2). But even as late at 1963, a nationwide survey by the National Association of Corrosion Engineers indicated that such corrosion was not a major concern in the U.S. petroleum industry, except for a few refineries on the West Coast (3). Nonetheless, the survey concluded that further research was warranted to determine how to predict potential naphthenic acid corrosion from a particular crude and to determine cause and effect relationships with respect to corrosion rates.