Factors affecting conversion of methane-hydrogen mixtures into nanostructured carbon and hydrogen

Abstract

At the catalytic decomposition of methane, along with hydrogen, it is possible to obtain carbon nanofibers. The addition of hydrogen to the initial reaction mixture makes it possible to increase significantly the efficiency of the overall process by minimizing the contribution of the catalyst deactivation process caused by coking. As found, the maximum yields of hydrogen and nanostructured carbon over the NiO–CuO/Al2O3 catalyst is achieved at an inlet hydrogen concentration of 13 vol%. The accumulated carbon is represented by well-structured carbon nanofibers, which are resistant to the gasification reaction. The original stacked structure is preserved after the treatment of these fibers in a hydrogen medium. Using numerical methods, the hydrogen productivity at 610 °C was found to be 49.3 mL/(mgcat·h) at an optimal value of the residence time of 5 × 10−3 s.