Physical Transformation Processes Of Forest Biomass: Chipping, Bundling, Drying And Control Of Particle Size Distribution

Abstract

Forest biomass is characterized by physical properties such as high moisture content, low density and heterogeneous particle size, which condition its direct use for combustion. Hence, processes of physical transformation are previously required to obtain products of higher energetic value, reducing transport costs and allowing for homogeneous boiler feeding. The biomass harvesting processes, as well as the logistic options for chipping and bundling, are described in this chapter, which offers a summary of the costs of such operations measured in forest biomass logistic studies in Spain. Studies on natural versus controlled drying of chips and bundles are also discussed, and general recommendations for the management of moisture content and the prevention of self-ignition risk during storage are given. Finally, experiments to date involving the screening and size reduction of forest biomass are summarized.