Development of an Efficient Method to Blend Forest Biomass with Agricultural Residue to Produce Fuel Pellets with Improved Mechanical Properties

The use of agricultural residues to produce pellets for energy use is a possible option for the recycling and upgrading of waste materials. Unfortunately, agricultural residue pellets suffer from poor mechanical and physical-thermal properties. In this paper, we address the blending of such residues with forest biomass in different proportions in view of the production of pellets featuring improved properties, which could then be used in practical applications. Namely, eucalyptus sawdust was added to pearl millet cob and corncob. Such a combination of feedstock, never addressed in the literature before, allowed for: an increase in burning time (from 482 to 562 and from 375 to 660 s for pearl millet cob and corncob, respectively) due to an increase in bulk density, a substantial increase in ultimate and compressive strength, impact, abrasive, and water resistance, which all improve the storage and handling properties of the produced pellets. Such improvements in properties can substantially increase the management and appeal for the commercialization of agricultural residues as feedstock for pellet production.