A study has been conducted on co-gasification of blended lignite and wood on the performance of a 100 kW dual fluidised bed (DFB) steam gasifier. In the experiments, inert silica sand was used as the bed material and the operating temperature in the bubbling fluidised bed gasification reactor (BFB) was controlled at 800 degrees C while that in the fast fluidised bed combustion reactor (FFB) was maintained at 850 degrees C. Lignite was blended with radiata pine sawdust at mass ratios of lignite in the blend being 0% (or 100% wood), 40%, 70% and 80%, respectively. The blends were then pelletised for the tests. For the 100% lignite run, lignite particles supplied (without pelletising) were used. From the experimental results, it was found that the producer gas yield and producer gas compositions were non-linearly correlated to the lignite to wood ratio, which shows a synergy with the pelletising blending. The experimental results also show that with the lignite to wood ratio increasing from 0% to 100%, the H-2/CO ratio increased asymptotically from 1.0 to 2.4 while the tar concentration and tar yield decreased from 9.0 to 2.7 g/N m(3) and from 6.6 to 2.3 g/kg(dry fuel), respectively. The optimum H-2/CO ratio of 2 for Fischer-Tropsch synthesis can be achieved by blending 40% lignite and 60% wood as feedstock, therefore, use of expensive catalytic bed material or increase of gasification temperature over 800 degrees C to achieve this target H-2/CO ratio may not be necessary. (C) 2013 Elsevier Ltd. All rights reserved.