Biomass Gasification Modeling: From Reactions to Processes
Résumé
The thermochemical conversion of lignocellulosic biomass is still difficult to understand and model, whereas there is an
industrial need for process simulation in order to conceive new plants. Accurate models are needed to predict product
composition, that are often complex. In this communication, biomass gasification modeling in bubbling fluidized bed is presented. This model has been developed on the basis of literature data, but also through the studies of bed segregation and tar gas-phase conversion, two phenomena that are not yet well understood. Bed segregation has been characterized in a cold fluidized bed with olivine sand and different wood particles (Ref 1). Tar gas-phase conversion has been modeled with detailed radical kinetic model under Chemkin Pro® and the results have been treated to get a lumped kinetic model. Finally, the whole gasifier model has been solved numerically through the combination of two softwares: Matlab® and Aspen Plus®. The simulated gas composition profiles are compared with experimental data obtained thanks to a new fluidized bed pilot. It will be also shown how this type of reactor model can be used under Aspen Plus® to simulate a whole gasification process. This type of process simulation allows to build accurate mass & energy balances (Ref 2), that could be used in technicoeconomic and/or LCA studies (Ref 3).