| Abstract |
The report examines the technologies used for drying of biomass and the energy requirements of biomass dryers. Biomass drying processes, drying methods, and the conventional types of dryers are surveyed generally. Drying methods and dryer studies using superheated steam as the drying medium are discussed more closely, with comparison to the methods of drying using air or flue gas as the drying medium. Available types of steam dryers are described with reference to operating conditions, energy requirements, and types of biomass dried. Energy aspects are considered, as well as possibilities of steam utilization to recover the latent heat of vaporization. Thermal energy required for drying of biomass is calculated using tabulated values of steam properties. The amount of steam to provide the thermal energy needed for biomass drying, at different pressures and temperatures applicable in steam dryers, is calculated for both indirectly and directly heated steam dryers. The calculated heat requirement values of steam dryers have been compared with those reported in the literature. Further, anticipated emissions from fluegas and steam drying processes have been summarized. |
