Study of corrosion of AISI 420 in the CO 2 absorption process using 2-amino-2-methyl-1-propanol aqueous solutions

Abstract

In this work, the corrosion behaviour of the stainless steel AISI 420 in the CO₂ absorption systems using aqueous 2-amino-2-methyl-1-propanol (AMP) solutions is studied. Three process parameters were considered: temperature (293-323 K), amine concentration (0·1-2·0 kmol m⁻³) and CO₂ flow (0·0-0·5 L min⁻¹). Electrochemical techniques were used to determine the corrosion rate by means of a potentiostat. For each experiment, the electrochemical parameters (corrosion potential and current, anodic and cathodic slopes) were calculated, as well as the corrosion rate, using the Tafel method. At the same time, the pitting susceptibility was evaluated by potentiodynamic tests. According to the results, the influence of the studied variables and the steel characteristics on the polarisation curves and corrosion rate was analysed. Experimental results show that an increase in solution temperature and AMP concentration causes higher corrosion rate. The obtained results indicate that it is not likely to have pitting corrosion in these systems.