Oxidative self heating of stored bagasse (sugar cane residue), which is largely composed of cellulosic compounds gives rise to many expensive problems for the sugar industry, not the least being spontaneous ignition of storage piles, and consequent pollution and loss of value. The self-heating reaction is known experimentally to be water dependent at temperatures below 100 degrees C, and the realistic mathematical formulation of the problem has to include both evaporation of water and condensation of water vapour and also their heating and cooling effects. Removal of water from the bagasse is important, as dry bagasse is both a more efficient and less environmentally destructive fuel.
In this project we are using numerical computation and approximate analytical models to explore the bifurcation behaviour of bagasse piles using one and two-dimensional models. The mathematical structure of the solutions can assist in determining optimal storage modes and bagasse pile configurations to allow the drying out of bagasse piles, without allowing spontaneous combustion. These ideas will be tested by detailed comparisons with measurements taken from full-scale piles in Queensland. This project was supported by the ARC under the SPIRT scheme from mid 1998-mid 2000.
See also the School mathematical combustion page.