Bed shrinkage in packed bed biomass combustion

Abstract

This paper focuses on evaluating shrinkage of a biomass packed bed. A laboratory scale packed bed is designed to conduct experiments in batch mode. Different types of biomass i.e. Ginisiriya, coconut shells and rubber are used for the packed bed to study the behavior of bed shrinkage. The model uses inlet air stream at room temperature as the gasifying medium and a fixed batch of biomass. Ignition of the biomass batch is initiated by an external heat source. Further operation is maintained by the own heat emitted by combustion reactions, until the whole batch is finished. As the time goes height of the packed bed is decreasing due the shrinkage of the bed. Empirical data obtained from this model can be used to evaluate the bed shrinkage and temperature variations in solid phase and gas phase with time.