NOMATEN HYBRID-SEMINAR May 20: Investigating the protective characteristics of FeCO3 corrosion product layers that form at different CO2 partial pressures.

NOMATEN HYBRID-SEMINAR

online: https://meet.goto.com/NCBJmeetings/nomaten-seminar
In-person: NOMATEN seminar room (102)

Tuesday, MAY 20^th  2025 1 PM (CET)

Investigating the protective characteristics of FeCO₃ corrosion product layers that form at different CO₂ partial pressures.

Amber Sykes
University of Leeds

Abstract:

The presence of dissolved carbon dioxide (CO₂) in geothermal process fluids acidifies the environment and accelerates the corrosion of the carbon steel pipes. Under certain conditions, the precipitation of iron carbonate (FeCO₃) corrosion products onto pipeline walls can form a protective layer that significantly reduces further corrosion rates. To accurately predict corrosion rates in these environments, an improved understanding of the protective properties of FeCO₃ layers is required.

In this study, autoclave corrosion testing is performed using CO₂-saturated, 3 wt.% sodium chloride brine at an operating temperature of 80 °C and CO₂ partial pressures ranging from 5.5 to 15.5 bar. In-situ linear polarisation resistance analysis demonstrates how operating pressure influences the rate of formation of FeCO₃. The evolution of the FeCO₃ layer is also investigated using Electrochemical Impedance Spectroscopy. This technique demonstrates how the mechanism for protection offered by the FeCO₃ layer transitions from initially blocking active sites, to providing additional corrosion suppression by restricting the diffusion of ions to the underlying metal surface.

Bio:

Amber Sykes is a PhD student at the University of Leeds, within the Institute of Functional Surfaces, where she is researching iron carbonate corrosion product formation in geothermal environments. Her supervisors are Professor Richard Barker and Dr Joshua Owen, and her industrial sponsors are LBBC Baskerville.