NOVELTY - Thermal biological breakdown and dewatering of biomass involves leading biological residue material (8) from digesting tank (6) to dewatering device (9) and dewatering the material to 15-25% dry matter; leading dewatered material (10) to device and carrying out thermal hydrolysis at 145-170 degrees C for 10-40 minutes; subjecting the hydrolyzed biomass (14) to quick pressure reduction; dewatering the thermally hydrolyzed and steam exploded hot biomass at 85-105 degrees C in closed dewatering unit (16); cooling dewatered biomass (18) in cooler (19); and leading liquid phase (17) from dewatering unit.    USE - For thermal biological breakdown and dewatering of biomass; and as device for thermal biological breakdown and dewatering of biomass (claimed).    ADVANTAGE - The method optimizes dewatering of the biological residue from the digesting tank to minimize transport of the dewatered biological residue, and also to increase the energy yield from the biomass that is led to the digesting tank.    DETAILED DESCRIPTION - Thermal biological breakdown and dewatering of biomass involves leading the biological residue material (8) from a digesting tank (6) to a dewatering device (9) and dewatering the material to 15-25% dry matter; leading the dewatered material (10) to a device and carrying out a thermal hydrolysis at 145-170 degrees C for 10-40 minutes; subjecting the hydrolyzed biomass (14) to a quick pressure reduction that results in a steam explosion in the biomass; dewatering the thermally hydrolyzed and steam exploded hot biomass, at 85-105 degrees C in a closed dewatering unit (16), a centrifuge, to 35-60% dry matter; cooling the dewatered biomass (18) in a cooler (19), preferably an air-cooler and dewatering the biomass further by evaporation to 40-75% dry matter; and leading the liquid phase (17) from the dewatering unit, which contains considerable amounts of hydrolyzed organic matter upstream of the digesting tank for increased production of biogas. An INDEPENDENT CLAIM is included for device for thermal biological breakdown and dewatering of biomass comprising a digesting tank for degradation of the biomass; a first dewatering device; a device for thermal hydrolysis and pressure reduction/steam explosion; a second dewatering device; and a cooler.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the method of thermal biological breakdown and dewatering of biomass.    Digesting tank (6)    Biological residue material (8)    Dewatering device (9)    Dewatered material (10)    Hydrolyzed biomass (14)    Closed dewatering unit (16)    Liquid phase (17)    Dewatered biomass (18)    Cooler (19)