(391a) Copper as An Oxygen Carrier in a Chemical Looping Combustion System: Reaction Kinetics and Fluidized Bed Performance

In order to better classify potential oxygen carriers for a Chemical-Looping Combustion system, a lab-scale bubbling fluidized bed reactor has been designed and built at the University of Utah. In order to simulate a dual-fluidized bed system, the reacting gas is cycled between the oxidizing gas (Air) and the fuel gas (CH4 or H2/CO mixture). Volume percentages of CH4, CO, CO2 and O2 are analyzed in real time by a CAI NDIR/O2 gas analyzer. Copper has been identified as a potential CLOU (chemical looping with oxygen uncoupling) material. A CLOU material has the ability to both bind and release oxygen under different atmospheres without the aid of a reducing agent. This is particularly useful for combustion of solid fuels. In order to overcome the low melting point and associated sintering propensity of pure copper, a titanium oxide support was used. Tests to characterize performance of the supported copper as an oxygen carrier have been conducted at temperatures ranging from 750°C to 950°C. One test was conducted for 24 hours in order to determine the long term performance of copper. Development of internal surface area and particle morphology as a function of the number of looping cycles is presented. Such data is important when considering applicability in industrial systems where attrition resistance and long-term reactivity are important. This paper describes the experimental approach, data analysis and assessment of the potential for copper as a carrier in full-scale systems.