UNUSUAL ASPECTS OF CORROSION FAILURES IN REFINERY HYDROTREATER UNITS

摘要

During the past several years Whiting Refinery has experienced three unusual corrosion failures in hydrotreaterrnunits. The first failure occurred in a furnace-to-reactor line in an old distillate desulfurization unit. This failure wasrncaused by localized high temperature sulfidic corrosion in an unexpected location. Another failure occurred in anrnair cooler outlet nozzle in a unit which desulfurizes feed to catalytic cracking units. This failure was an example ofrnammonium bisulfide corrosion that was enhanced by unusual operating conditions. The third failure occurred in arnproduct stripper vessel on a unit that desulfurizes diesel. This failure was by deposit formation beneath the toprntray of a tower. This paper reviews the circumstances which led to these failures and highlights the lessonsrnlearned from each failure.