Heat transfer controlled pyrolysis kinetics of a biomass slab, rod or sphere

A theory for deriving the pyrolysis rate of a single infinite slab, infinite cylinder or sphere in a constant temperature furnace is suggested. In analogy with the shrinking-core model a pyrolysis propagation front velocity is defined. The velocity is thereafter used in a compartment-model approach for deriving a set of ordinary differential equations for solving the burn-off over time. A comparison with experimental and published data is also made.