Keynote Talk: Assessment of Combustion and Gasification Behaviour in Pilot Scale for Additivated Biomass

During the storage of biogenic materials for energy utilization, destruction and conversion processes by bacteria and fungi take place inevitably. Besides the wood degradation, self-ignition of wood chip piles occurs consistently. Additivation of eg. Dolomite to the feedstock can inhibit microbial desctruction processes. Wood chips mixed with 3wt% calcium hydroxide was prepared and used as feed stock for a 20kW (fuel input) bubbling fluidized bed pilot plant. The reactor consists of a 100mm (innder diameter) bubbling bed reactor with 2m height and both gasification as well as combustion mode can be applied. The fluidization behaviour at different reaction temperatures (750-900°C) for combustion as well as for gasification with air was analysed. As feedstock the original biomass as well as the wood chips with additive was used. The producer gas was measured and compared for each feedstock and process parameter. The measurements are set into reference to calculation of mass and energy balances of the conversion of feedstock to syngas respectively thermal energy. Summarizing, the combustion as well as the gasification behaviour was hardly influenced by the additive.