NOVELTY - The method for treating and/or processing a liquid fermentation residue from a fermenter (2) and/or a post-fermenter (3) of a biogas plant (1), comprises supplying a predetermined quantity of liquid fermentation residue from the fermenter and/or post-fermenter to a drying device, which is arranged downstream to the fermenter and/or post-fermenter of the biogas plant, and supplying a thermal energy to the drying device, where the thermal energy is area-wisely coupled from an internal heat source formed by a biogas-thermal power station of the biogas plant and is fed to the drying device.    USE - The method is useful for treating and/or processing a liquid fermentation residue from a fermenter and/or a post-fermenter of a biogas plant for large agricultural operations.    ADVANTAGE - The method is capable of efficiently, rapidly and safely treating and/or processing the liquid fermentation residue with less effort.    DETAILED DESCRIPTION - The method for treating and/or processing a liquid fermentation residue from a fermenter (2) and/or a post-fermenter (3) of a biogas plant (1), comprises supplying a predetermined quantity of liquid fermentation residue from the fermenter and/or post-fermenter to a drying device, which is arranged downstream to the fermenter and/or post-fermenter of the biogas plant, and supplying a thermal energy to the drying device, where the thermal energy is area-wisely coupled from an internal heat source formed by a biogas-thermal power station of the biogas plant and is fed to the drying device, so that a dry matter content of the dried fermentation residue is increased to a predetermined value of 80-85% of dry matter content. The biogas-thermal power station of the biogas plant comprises an internal combustion engine, an exhaust air device, an exhaust gas device and/or a cooling circuit. The thermal energy is provided from the hot exhaust air of the internal combustion engine surroundings, from the hot combustion gases of the internal combustion engine and/or from the cooling circuit of the biogas-thermal power station of the biogas plant and is coupled into a drying chamber of the drying device directly or indirectly over a heat exchanger. The predetermined quantity of the dried fermentation residue is introduced into the drying chamber of the drying device using a feeding device. A part of the liquid fermentation residue to be dried is mixed with a predetermined quantity of an already dried fermentation residue before it is supplied to the drying chamber for the adjustment of the predetermined dry matter content of the mixed fermentation residue of 50% TS to be dried. The mixed fermentation residue to be dried introduced into the drying chamber is brought to a conveying device using the feeding device. The predetermined quantity of the continuously or batch-wisely delivered mixed fermentation residue is continuously or clock-wisely transported through the drying chamber using the conveying device for a predetermined retention time and is subjected with the thermal energy. The feeding quantity, the feed time and/or the feed rate of the conveying device, the timing of the conveying device and/or the retention time in the drying chamber are given, so that the fermentation residue to be dried is dried at the end of a drying section at the predetermined dry matter content. The ammonium-containing exhaust air from the drying chamber is led out from the drying chamber of the drying device over a chamber-side arranged one- or multi-stage exhaust air scrubber. The exhaust air is washed with sulfuric acid, so that the ammonia is washed out from the exhaust air and ammonium sulfate is formed, which is removed from the exhaust air scrubber and is supplied to a storage container. A control device and/or a regulating device is provided, by which the feeding of the drying device with the fermentation residue to be dried, the admixture of the fermentation residue to be dried from liquid fermentation residue and dried fermentation residue, the supply of the sulfuric acid to the exhaust air scrubber for the ammonium-containing exhaust air of the drying device, the supply of thermal energy to the drying device in dependent of the predetermined drying parameter such as temperature in the drying chamber, the quantity of the fermentation residue load to be dried, the temperature and/or the quantity of the thermal energy provided for drying and/or the dry matter content of the fermentation residue to be dried is controlled and/or regulated. The fermenter of the biogas plant is arranged upstream to a fermenter-feeding system, which has a cell disruption extruder, by which a part of the biomass (9) to be fermented, which is supplied to the fermenter, is thermo-mechanically decomposed. An INDEPENDENT CLAIM is included for a device for treating and/or processing a liquid fermentation residue from a fermenter and/or a post-fermenter of a biogas plant.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a biogas plant with a cell disruption device upstream to a fermenter.    Biogas plant (1)    Fermenter (2)    Post-fermenter (3)    Outlet nozzle (8)    Biomass. (9)