TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The biomass residue comprise at least one residue selected from sawdust; bagasses; wastes from agricultural activities, from food industries and from reforestation processes; natural or cultivated residues from land or sea; vegetable organisms; and organic products derived from the biological activity of animals and humans.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The larger non-usable contaminating residues are separated from usable residues (R2) by means of a separator (S2) prior to step (b). The conveying and feeding conduit works by a screw-conveyor or Redler system and provides continuous feeding to the drying system. The method involves separating coarser residues in a separator (S4) and grinding them in a grinder (G1) prior to step (c). The residues ground in (G1) follow to step (c). During step (b), separating the heavier residues from less heavy residues is carried out in a separator (S3). The fine residues separated in step (d) comprise silica or other inorganic impurities. The fine residues separated in step (d) are used as fuel in the hot-air generator.Preferred Components: The separator (S2) comprises a disc system with speed variations. The residues (R2) comprise plastics, paper and fabrics. The drying system is fed by means of a conveying and feeding conduit. The drying system and the hot-air generator are controlled by pressure and temperature measuring devices and have emergency deviation devices. The drying system is a rotary-drum drying system or a conduit drying system. The drying system uses either hot air with a temperature gradient between its the inlet and the outlet; or hot air at a constant temperature throughout the system. The hot air in the drying system is at a temperature up to 4500degreesC. The separator (S3) comprises a system working like a siphon and a lower reservoir for holding the heavier residues such as small solid grains, such as sand, glass and metal. The coarser residues are greater than or equal to 2 cm. The separator (S1) is a vibratory separator. The pelletizer comprises a roller system against a wall that has small orifices 6 - 25 mm. The external part of the wall has rotary blades that cut the residues to give rise to the pellets. EXAMPLE - 3000 Kg of biomass residues from sugar-cane bagasse was charged into a deposit. The charge was divided into 2 parts of 1500 kg each to follow by different drying systems. 1500 Kg of biomass residues was dried in a rotary-drum drying system through hot air from a hot-air generator. In this drying system, the hot air had an inlet temperature of 450 degreesC and an outlet temperature of 60 degreesC. 1    500 Kg of biomass residues was dried in a conduit drying system (pipeline-type) through hot air from a hot-air generator. In this system, the hot air had a constant temperature of about 250 degreesC.    After the biomass residues from both drying systems had been dried, they were subjected to a refining step, using a 5 mm-mesh refiner.    The refined biomass residues followed to a pneumatic vibratory separator to remove fine contaminants, such as silica and other inorganic impurities. A 1 mm-mesh separator was used, thus separating 2 fractions: fine residues of a size equal or smaller than 1 mm and residues suitable for the production with a size ranging from 1 to 5 mm. The percentage of fine residues was of 13-15%, a sufficient amount to feed the hot-air generator. The residues suitable for the production having size between 1 and 5 mm followed then to a pelletizer, without the use of agglutinant or vapor. The compaction thus formed pellet exhibited 10% moisture, ash contents lower than 1 % and temperature of 60 degreesC, a cooling step being unnecessary, and it could follow directly to a storage silo. An embodiment of the invention having been described, one should understand that the present invention embraces other embodiments, being limited only by the scope of the accompanying claims.