A fluidized-bed gasifier is under construction to produce a synthesis gas from biomass. The plant will include a complete system for wood residues handling, shredding, drying, and storing. The reactor is designed to gasify 10 tons of wood residues/h, using O as fluidizing agent. The optimization of process will provide optimal parameters of moisture content in the biomass, operating pressures, amount of O/ton biomass, C conversion, heating value of gas, tar formation, and all other data which might influence the economic performance of the gasification system. The demonstration includes a research and development program and a math. model to better define the interfaces and the best configuration of gasifier-reformer-shift-reactor for later synthesis operations.