Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
Considerable research has been devoted towards
determining the kinetics of the pyrolysis of lignocellulosic
biomass such as wood residues and agricultural waste. In this
study, we have developed a finite element model (FEM) in
order to simulate the coupled heat and mass transfer
phenomena during pyrolysis. The resulting sets of partial
differential equations were then solved simultaneously using
the COMSOL Multiphisics software package. This numerical
modelling and simulation approach helped the visualization of
the process. In this work, cylindrical sections of birch wood
biomass were pyrolysed in a laboratory-scale thermal
desorption unit. The influences of final pyrolysis temperature,
and pyrolysis holding time on the biochar yields were
investigated. Results showed that with increase in time and
temperature, the yield of total pyrolysis products decreased. On
the other hand, higher pyrolysis temperatures and holding times
resulted in the increase of char content in the wood for fast
pyrolysis. A technique to maximize the amount of char in the
product was also identified through by optimizing the
parameters within the temperature range of this study