Abstract: Biomass is a widely available renewable energy source, which could be an alternative fuel source to fossil fuels to alleviate environmental problems. Biomass Pyrolysis and gasification is a promising approach for combined heat and power generation and for the production of various products such as fuels and chemicals. Gas-solid fluidized-bed offers excellent mixing, heat and mass transfer between solid particles and fluidizing gas, thus is one of the most interesting technologies.