Transient temperature and char conversion profiles in wood during devolatilization in a fluidized bed combustor

Transient temperature history, char conversion profiles, and the temperature window for devolatilisation are presented for a wood particle in a Fluidised Bed Combustor (FBC) using a three dimensional transient model. Cube shaped wood particles of size 10 mm and 25 mm, with initial moisture content (6%, 12%, and 50%) were studied. Experiments were conducted in a fluidized bed combustor of 130 mm diameter with a bed height of 130 mm, to validate the model for total devolatilisation time. The temperature gradient within the wood particle was found to be steeper across the grain (transverse direction) than along the grain (longitudinal direction). The temperaturewindow of devolatilization was found to be about 550-850 K under the conditions of the study.