Validation of a multiparameter model to investigate torrefied biomass pelletization behavior

The present study aims to apply and validate a simple model describing the forces that are built up along the dies of a pellet press matrix to the pelletization of torrefied biomass. The model combines a theoretical background with the use of a single pellet press to describe the pelletizing behavior of torrefied material in an industrial scale pellet mill. Wet torrefaction and dry torrefaction pretreatments are considered in the study. Both torrefaction concepts produce a fuel with enhanced properties including a lower moisture content, higher calorific value, and better friability. The fuel shows closer properties to coal and it is more economical to transport and better to store due to its hydrophobic characteristics. The goal of the present study is to allow for a fast estimation of important pelletization process parameters, to get a better understanding of the pelletization process and to avoid time consuming as well as expensive trial and error experiments.