Catalytic combustion of methane over red mud-based catalysts

Three iron-based catalysts were prepared from waste materials from the aluminium industry (red mud (RM)) by dissolution-precipitation methods, followed by calcination in air at 500degreesC for 2 h. The activity and stability of those materials for the catalytic combustion of methane was studied at atmospheric pressure, temperatures between 300 and 626 degreesC and space time between 106 and 526 g h/mol of methane (WHSV = 48 h(-1)), and compared to that of hematite and a Cu-Cr-Ti commercial catalyst. The kinetics of the reaction was successfully modelled considering pseudo-first order dependence on methane partial pressure. Superficial characterisation of fresh and used catalysts were carried out by BET, X-ray diffraction (XRD) and temperature programmed techniques. Results obtained indicate that red mud activated by the method of Pratt and Christoverson exhibits higher catalytic activity and good thermal stability. (C) 2003 Elsevier B.V. All rights reserved.