Effect of steam reforming on methane-fueled chemical looping combustion with Cu-based oxygen carrier

The reduction characteristics of Cu-based oxygen carrier with H2, CO and CH4 were investigated using a fixed bed reactor, TPR and TGA. Results showed that temperatures for the complete reduction of Cu-based oxygen carrier with H2 and CO are 300 °C and 225 °C, respectively, while the corresponding temperature with CH4 is 650 °C. The carbon deposition from CH4 occurred at over 550 °C. CO-chemisorption experiments were also conducted on the oxygen carrier, and it was indicated that Cu-based oxygen carrier sinter seriously at 700 °C. In order to lower the required reduction temperature of oxygen carriers, a new chemical looping combustion (CLC) process with CH4 steam reforming has been presented in this paper. The basic feasibility of the process was illustrated using CuO–SiO2. The new CLC process has the potential to replace the conventional gas-fired middle- and low-pressure steam and hot water boilers.