Enhancing performance of low-temperature chemical looping steam methane reforming through transition metal doping in $LaCoO_3$ oxygen carrier

Abstract

Chemical looping steam methane reforming (CL-SMR) is a valuable technology in the aspect of producing pure hydrogen and optimized ratio of syngas simultaneously. Since the efficiency of CL-SMR is highly influenced by the type of oxygen carrier, finding suitable oxygen carrier is a challenging work. Present study is about effects of doping transition metal on the B-site of $LaCoO_3$ for the low-temperature CL-SMR. To achieve this work, three different oxygen carrier were synthesized, which were $LaCoO_3$, La$Co_{0.6}$$Fe_{0.4}$$O_3$, and La$Co_{0.6}$$Mn_{0.4}$$O_3$. And the performance and stability of each oxygen carrier was tested by cyclic redox experiment. As a result, it was found that La$Co_{0.6}$$Fe_{0.4}$$O_3$ showed the best performance in both of the steam regeneration and the hydrogen purity. Through the experiment, this study can propose that La$Co_{0.6}$$Fe_{0.4}$$O_3$ is the most promising oxygen carrier for the low-temperature CL-SMR. The most encouraging result is that chemical looping steam methane reforming has been successfully performed at relatively low temperature of 700˚C without the use of special and expensive materials such as noble metals.