A recently improved NETL oxygen carrier based on low-cost minerals demonstrated a ten-fold increase in durability compared to previous iterations. This record-breaking accomplishment represents a significant step toward the commercialization of chemical looping combustion (CLC), an advanced fossil energy technology capable of delivering affordable and dependable power to the nation while reducing environmental impacts due to CLC’s more streamlined carbon dioxide (CO2) capture capability.
“Oxygen carriers are critical components of CLC, creating oxygen in-situ, which eliminates the need to separate oxygen from the air,” said Ranjani Siriwardane, Ph.D., who codeveloped the oxygen carriers. “The combustion of fossil fuels in nearly pure oxygen, rather than air, presents an opportunity to simplify CO2 capture in power plant applications.”
Because oxygen carrier durability is a major technology barrier for the success of chemical looping combustion, this demonstration of improved durability will help push the technology closer to commercialization, enabling higher power plant efficiencies while simultaneously mitigating CO2 emissions — all at a cost roughly 25% lower than conventional technologies.
Siriwardane developed the improved oxygen carriers with NETL researcher Jarrett Riley, Ph.D., as well as a former research intern William Benincosa, Ph.D., to overcome previous issues of durability by increasing resistance to particle loss, which is referred to as attrition. While other materials tested at the Lab have resulted in attrition equivalent to $30–1700 per megawatt hour (MWh), the new NETL oxygen carriers demonstrated minimal losses equivalent to only $1 per MWh.
“In addition to being more durable, these oxygen carriers were prepared primarily using less-expensive natural mineral grade raw materials, which will make the CLC process more economical,” said Riley.
The ground-breaking testing took place at the Lab’s 50kW chemical looping reactor test facility in Morgantown, West Virginia. The 54 hours of testing, led by NETL researcher Douglass Straub and assisted by NETL researchers Justin Weber and Samuel Bayham, Ph.D., was the longest such test at NETL and a major accomplishment in chemical looping technology research worldwide.