Catalytic combustion of low heating value fuels is a promising method for electricity production combining the use of a renewable fuel with ultra-low emissions. In the present work, catalytic combustion of a low heating value gas has been studied over monolithic catalysts in an atmospheric 30 kW pilot catalytic combustor connected to a wood pellet gasifier. The results have been compared to similar tests with a model gas mixture and a series of test in a laboratory scale reactor for monolithic samples. Various catalyst configurations have been tested, such as precious metal-based catalyst impregnated on modified alumina washcoats and hexaaluminate washcoats. Cordierite monoliths with various cells per square inch were used as supports, but hexaaluminate extruded monoliths were also used. The catalysts were combined in different segment series. The results show that it is possible to ignite the low heating value gas at compressor outlet temperatures without the use of pre-burners over precious metal catalysts. Generally, trends and phenomena obtained in laboratory reactor operating close to isothermal could be confirmed in the pilot operating at close to adiabatic conditions. Further results, such as deactivation by sulphur compounds, fuel-NOx conversion and emissions of carbon monoxide and total hydrocarbons, are addressed in the paper. (C) 2000 Elsevier Science B.V. All rights reserved.