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.