The tar reforming catalytic activity of iron and nickel based catalysts supported on alkaline-earth oxides CaO, MgO and calcined dolomite [a (CaMg)O solid solution] has been investigated in a fixed bed reactor operating at temperatures ranging from 650 to 850 degrees C; toluene and 1-methyl naphthalene were used as model compounds for tar generated during biomass gasification. The CO2 absorption capacities of Fe/(CaMg)O and Ni/(CaMg)O were also investigated at the lower temperature condition (650 degrees C) at which the sorption process is thermodynamically favoured. It was found that iron and nickel may be optimised in the substrate particles to enhance both the catalytic activity and the carbon deposition resistance during catalytic tests, at the same time reducing critical limitations on CO2 capture capacity. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.