Understanding the corrosion of CO2-loaded 2-amino-2-methyl-1-propanol solutions assisted by thermodynamic modeling. (November 2016)

• Record Type: Journal Article
• Authors: Zheng, Liangfu; Matin, Naser S.; Thompson, Jesse; Landon, James; Holubowitch, Nicolas E.; Liu, Kunlei
• Is Part Of: International journal of greenhouse gas control. Volume 54:Part 1(2016:Nov.)
• Page Start: 211
• Page End: 218
• Publication Date: 2016-11
• Subjects: Sterically hindered amine -- AMP -- Corrosion -- Steel -- Thermodynamic modeling -- Passivity; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2016.09.005
• Languages: English
• ISSNs: 1750-5836

Abstract

Highlights: Corrosivity of AMP is investigated with SEM, XRD, FIB and thermodynamic modeling. Liquid phase speciation was determined by employing an electrolyte-NRTL model. HCO3 − concentration plays an important role in the formation of protective FeCO3 . FeCO3 is metastable in amine solution with dissolved O2 and passivation occurs. Lower corrosion occurs in AMP than in MEA due to faster FeCO3 & Fe3 O4 formation. Abstract: Corrosion of A106 carbon steel in a naturally aerated 30 wt.% 2-amino-2-methyl-1-propanol-based solution (AMP, a sterically hindered primary amine) with 0.43 molCO2 /molAMP was evaluated at 80 °C. Substantial decrease in corrosion rate, i.e., over two orders of magnitude, was observed over the initial 70 h, which is the result of formation of a protective FeCO3 layer followed by passivation of the A106 surface. Mechanisms for formation of these protective layers are discussed with comparison to corrosion in a 30 wt.% monoethanolamine solution as well as with the help of thermodynamic modeling of the AMP-H2 O-CO2 system. Experimental solubility data from literature were employed to extract a thermodynamic model for aqueous solutions of AMP with concentrations ranging from 17.8 to 36.6 wt.% at various CO2 loadings. Liquid phase speciation was determined by employing an electrolyte-NRTL model. The AMP carbamate stability constant, molecule-ion pair, and molecule–molecule interaction parameters in the studied concentrations were obtained. The determined CO2 equilibrium properties are in agreement with previously reported experimental data.