Role of heat stable amine salts on corrosion and corrosion inhibition in amine treating units

Recently, there has been a growing concern over the adverse impacts of heat stable amine salts (non-regenerable degradation products of amines) on the corrosion of process equipment in amine treating units, which remove acid gases (CO2 and H2S).;This study investigated the effect of 14 heat stable amine salt compounds on the corrosion on both CS-1018 and SS-304. Based on the results, heat stable amine salts did not alter the active state of the test metals, but it did have an apparent impact on corrosion in two ways. First, the heat stable salts, including oxalate, formate, malonate, glycolate, succinate, acetate, sulphate and chloride (as HCl) induced an increased uniform corrosion. Oxalate was the most corrosive, followed by formate and malonate. Higher salt concentration generally increased the corrosion rate. Second, the heat stable salts, including sulfite, chloride (as NaCl), two thiosulfate compounds and two thiocyanate compounds, retarded the rate of uniform corrosion.;This study also investigated the effect of heat stable amine salt on the performance of sodium metavanadate (NaVO3) and copper carbonate (CUCO3). Both NaVO3 and CUCO3 suppressed corrosion by forming stable passive films. The NaVO3, with above 96% inhibition efficiency and no pitting tendency, yielded superior performance over the CuCO3 that achieved between 81--93% and had some pitting tendency. (Abstract shortened by UMI.)...