| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advances in High-Temperature Oxidation and Degradation of Materials for Harsh Environments: A SMD and FMD Symposium Honoring Brian Gleeson
|
| Presentation Title |
Environmental Compatibility Issues for Ni-Based Alloys in Direct-Fired Supercritical CO2 Power Cycles |
| Author(s) |
Richard P. Oleksak, Casey S. Carney, Joseph H. Tylczak, Xueyan Song, Nicholas Lamprinakos, Anthony D. Rollett, Ömer N. Doğan |
| On-Site Speaker (Planned) |
Richard P. Oleksak |
| Abstract Scope |
Direct-fired supercritical CO2 (sCO2) power cycles offer potential for high-efficiency power generation from fossil fuels with built-in carbon capture. Ni-based superalloys are the leading candidates for the hottest portions of these systems, where they must endure long-term exposure to high-temperature, high-pressure, high-velocity, impure CO2-rich environments. Herein we describe results of various experimental testing campaigns showing that under such conditions, several simultaneously occurring degradation modes may be active including surface oxidation, alloy carburization, and oxide volatilization. It will be shown that the rates of degradation can be strongly affected by the alloy composition, impurities in the CO2, manufacturing method (wrought vs additive), and other factors. The influence of these factors in controlling alloy degradation are discussed in the context of potential compatibility issues for components in real sCO2 systems, such as compact heat exchangers. Finally, as a potential remedial measure, ongoing work involving protective coatings suitable for complex geometries is presented. |