NOVELTY - The method comprises feeding biomass in a fuel dryer (2), drying the biomass by circulating process air, supplying the process air damped in the fuel dryer to an air dryer (4), cooling the process air in the air dryer by heat exchange using a coolant (5) and then removing the process air by condensation, feeding the process air into a first heat exchanger (6) for heating, and guiding the process air between the fuel dryer and the air dryer by a blower (7). The biomass is comminuted during or after drying process, and is pelletized into shaped pieces after drying process.    USE - The method is useful for processing biomass, which is useful: in a heating plant; as a fertilizer; and for producing fuel (claimed).    ADVANTAGE - The method is capable of simply processing the biomass with less energy consumption.    DETAILED DESCRIPTION - The method comprises feeding biomass in a fuel dryer (2), drying the biomass by circulating process air, supplying the process air damped in the fuel dryer to an air dryer (4), cooling the process air in the air dryer by heat exchange using a coolant (5) and then removing the process air by condensation, feeding the process air into a first heat exchanger (6) for heating, and guiding the process air between the fuel dryer and the air dryer by a blower (7). The biomass is comminuted during or after drying process, and is pelletized into shaped pieces after drying process. The heat exchange is carried using a coolant by an evaporator, which is operated with a cooling machine that supplies the coolant to the evaporator. The process air is supplied to downstream of the first heat exchanger to increase the process temperature of a second heat exchanger. The second heat exchanger is supplied over a water circuit comprising an exhaust heat exchanger of a heating system. The biomass contains litter and manure, and is separated into its components such as litter and dung before feeding the biomass into the fuel dryer. INDEPENDENT CLAIMS are included for:    (1) a device for processing biomass;    (2) a method for operating a heating system; and    (3) a method for producing fuel from shaped bodies of biomass.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a device for processing biomass.    Fuel dryer (2)    Air dryer (4)    Coolant (5)    First heat exchanger (6)    Blower. (7)