Catalytic clean-up of emissions from small-scale combustion of biofuels

A knitted silica-fibre was prepared and used as support for combustion catalysts. Different Pd-MeO and Pt-MeO (Me = Ni, Co, Cu and Mn) catalysts were prepared, and their catalytic activities were investigated in the conversion of gas mixtures consisting of methane, ethene, naphthalene (model PAH), carbon monoxide, carbon dioxide, nitrogen and water vapour in the temperature range 150-800 degrees C. Combinations of Pd-Ni and Pt-Ni were found to result in decreased light-off temperatures in methane combustion. The Pd-Ni/silica-fibre catalyst exhibited a light-off temperature in methane combustion of cn 220 degrees C lower than that obtained over the Pd/silica-fibre catalyst. Deactivation of the catalysts was observed by subjecting the catalysts to reaction mixture flow at 800 degrees C for 6 h. For the Pd-containing catalysts, the deactivation was considered to be due to both support and metal sintering as well as changes in the nature of the Pd-O species. The catalysts were characterised by Na-adsorption, H-2-adsorption, O-2-TPD and H-2-TPR. (C) 1998 Elsevier Science Ltd. All lights reserved.