PREDICTION AND ASSESSMENT OF AMMONIUM BISULFIDE CORROSION UNDER REFINERY SOUR WATER SERVICE CONDITIONS --- PART 2

This paper summarizes results of Phase II of a joint industry program (JIP) to address ammonium bisulfide corrosion.  This phase of the program was focused on NH₃-dominated sour waters typically found in refinery services such as the overhead systems of some sour water stripper (SWS) units.  The Sour Water Phase II JIP extended the initial research work of the Sour Water Phase I JIP, reported in Corrosion 2006 Papers 06576 and 06577, that addressed ammonium bisulfide corrosion in H₂S-dominated sour waters.  This Phase II work in NH₃-dominated sour waters studied the impact of several process variables including NH₄HS concentration, NH₃ and H₂S partial pressure, temperature, cyanide concentration, and wall shear stress.  Data collected from laboratory tests designed to characterize these process variables were used to develop an updated software model to predict the corrosion rate of six materials evaluated in the program.  Key aspects of the data, parametric behavior, and corrosion response of different materials will be highlighted.