CCS and Power Systems
Crosscutting Research - Plant Optimization Technologies
Understanding Corrosion in Oxy-Fired Systems
Performer: Oak Ridge National Laboratory
Project No: FWP-FEAA106
Program Background and Project Benefits
In Oxy-fired Systems, oxygen is used for combustion of coal rather than air. It produces flue (exhaust) gas with concentrated carbon dioxide (CO2), thus facilitating its capture and sequestration. An added benefit of oxy-firing is that it reduces or eliminates nitrogen oxide (NOX) emissions.
Additional energy is required with oxy-firing and subsequent carbon sequestration in order to produce the oxygen, to capture the CO2 from the flue gas, and to process the CO2 for transport and storage. The reduced plant electrical output could be offset by an increase in plant efficiency with the use of an advanced steam cycle usually involving higher steam temperatures. Alloys that can perform under these more extreme conditions are available, but their performance in an oxy-firing fireside environment is not well understood, specifically regarding the role played by water (H2O) and CO2 during the oxy-firing process. Understanding how state-of-the-art alloys perform in an oxy-fired environment would provide a basis for their selection and use in advanced steam cycles, be useful for maintenance planning, and support the development of improved oxidation-resistant alloys and coatings.
The Department of Energy (DOE) National Energy Technology Laboratory (NETL) supports research and development of technologies that will increase efficiency and reduce emissions from power production plants, especially those fueled by coal. To further advance oxy-fired systems, NETL is partnering with Oak Ridge National Laboratory (ORNL) to address such key issues as (1) understanding temperature relevant corrosion mechanisms; (2) determining the role of the combustion environment on the mechanical response of the alloy; (3) evaluating upper temperature limits for new materials; and (4) characterizing corrosion reaction products and alloy degradation.
The primary benefit of this project is the creation of a knowledge base with the potential to support material selection and development for the demanding requirements of advanced, higher-efficiency steam cycles in order to reduce coal consumption and CO2 emissions while reducing the power requirements for CO2 capture, transport, and storage systems.