Experimental study on the axial mass transport of minced biomass (rape straw) into a pyrolysis rotating reactor working in the slipping regime

The paper presents an experimental study of the behavior of a minced biomass bed advancing into an inclined rotating drum to be used for biomass pyrolysis in the slipping regime. Minced rape straw was fed into the reactor with different feed rates, and its axial motion was examined at different slopes and cylinder rotating rates. By collecting and analysing images of the bed during the experimental runs, axial flow rates were determined; a mathematical model derived from mass and momentum balances was then applied, and the main parameter, the bed-wall friction factor, was obtained by regression of experimental data. Finally, in order to generalize bed dynamics, residence times and flow rates (mean values) were related to the experimental conditions by parametric semi-empirical and dimensionless correlations. Apart from its essential role in the future development of a whole chemical process model (including heat exchange, gas fluid dynamics, pyrolysis and gas phase reaction kinetics) to determine optimal working conditions, the dynamic model proposed here could also be of more general interest and be applied with other kinds of material and conditions on both an experimental and industrial scale.