Parametric study of the decomposition of methane using a NiCu/Al2O3 catalyst in a fluidized bed reactor

CO2-free production of hydrogen via catalytic decomposition of methane (CDM) was studied in a fluidized bed reactor (FBR) using a NiCu/Al2O3 catalyst. A parametric study of the effects of some process variables, including catalyst particle size, reaction temperature, space velocity and the ratio of gas flow velocity to the minimum fluidization velocity (u(o)/u(mf)), was undertaken. A mean particle size of 150 mu m allows optimization of results in terms of hydrogen production without agglomeration problems. The operating conditions strongly affect the catalyst performance: hydrogen production was enhanced by increasing operating temperature and lowering space velocity. However, increases in operating temperature, space velocity and the ratio u(o)/u(mf) provoked increases in the catalyst deactivation rate. At 700 degrees C, carbon was deposited as carbon nanofibers, while higher temperatures promoted the formation of encapsulating carbon, which led to rapid catalyst deactivation. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.