Title : Study on the effect of temperature on the evolution of corrosion product film and corrosion mechanism of carbon steel in alkanolamine solution
Abstract:
With the intensification of global warming, controlling CO2 emissions has become a consensus of the international community. CCUS (Carbon Capture, Utilization and Storage) is one of the key pathways for CO2 emission control. Post-combustion capture is widely adopted for large-scale CO2 capture in coal-fired power plants owing to its flexibility and ease of integration with existing power generation and industrial installations. Alkanolamine solutions represent the most effective and extensively used approach for post-combustion CO2 absorption; however, severe corrosion issues are associated with their application. There exists a significant temperature gradient between absorption towers and regeneration towers due to their distinct operating temperatures. To elucidate the effect of temperature on carbon capture systems, this study investigates the influence of temperature on the formation of corrosion product films and the corrosion behavior of carbon steel in alkanolamine solutions via weight loss measurements, electrochemical tests, SEM characterization, and other analytical methods. The study reveals that the corrosion rate increases gradually with the rise of temperature. The grain size of ferrous carbonate and the compactness of the corrosion product film are significantly affected by temperature. Specifically, the formed grain size is inversely proportional to the compactness of the film: the higher the ambient temperature, the larger the formed grain size and the greater the porosity of the film. A corrosion prediction model based on the corrosion product film has been established by incorporating the porosity of the corrosion product film, and this conclusion can provide a basis for the safe operation of CO2 capture systems.
