Biomass pyrolysis kinetics in a fluidized bed reactor: Measurements and plausibility verification for reaction conditions

A small-scale fluidized bed reactor is used to study pyrolysis kinetics of pulverized beech wood particles. The fluidized bed reactor realizes high particle heating rates (104 K/s) and high temperatures (up to 1473 K) to approximate flame-equivalent conditions of pulverized fuel boilers. Mass release rate is calculated based on time-dependent concentration profiles of 22 gas species measured with ex-situ FTIR gas analysis for batch-wise injected fuel samples. To verify if the determination of kinetic data from experiments is taking place in the reaction kinetic controlled regime, the Global Reaction Model (GRM) combined with an Arrhenius approach is used. A comparison with literature data shows that kinetic data can be measured reliable in the temperature range from 523 to 973 K. The obtained data sets are unique regarding their time resolution and number of investigated gas species, which promotes them to be used as validation data for network models in the given temperature range. For higher temperatures, the pyrolysis reaction is distorted by the insufficient gas transport to the ex-situ measurement device.