A method for the physical and thermochemical treatment of biomass, in particular of organic waste products, such as sludge from sewage treatment plants, slaughterhouses, agricultural operations, animal husbandry, the food industry, the paper industry, in which the following steps are performed in a treatment facility: - providing the biomass to be treated, - providing a drying device, - providing at least one pyrolysis reactor, - providing at least one combustion device, - providing at least one mixing device, - feeding the provided biomass to be treated into the drying device, wherein the moisture contained in the biomass is reduced and ammonia (NH 3) is released from the biomass during the drying process, - discharging the biomass to be treated from the drying device, - feeding the biomass to be treated into the pyrolysis reactor, - pyrolyzing the biomass in the pyrolysis reactor and, in the course of this, thermally decomposing the biomass into pyrolysis coke and pyrolysis gas, - discharging the pyrolysis coke and discharging the pyrolysis gas from the pyrolysis reactor, - feeding the pyrolysis gas discharged from the pyrolysis reactor into the combustion device and combusting the pyrolysis gas thus forming a flue gas, - discharging the flue gas from the combustion device and feeding the flue gas into the mixing device, - adding oxygen (O 2) and or at least an oxygen (O 2)-containing gas to the flue gas in the mixing device and forming a drying gas, said drying gas containing, inter alia, sulfur dioxide (SO 2) and/or sulfur trioxide (SO 3), each in a gaseous aggregate state, - discharging the drying gas from the mixing device and feeding the drying gas into the drying device, - guiding the drying gas through the drying device, wherein the sulfur dioxide (SO 2) and/or the sulfur trioxide (SO 3), which is inter alia contained in the drying gas, chemically reacts with the ammonia (NH 3) to ammonium sulfite ((NH 4) 2 SO 3) and/or ammonium sulfate ((NH 4) 2 SO 4). - providing the biomass to be treated, - providing a drying device, - providing at least one pyrolysis reactor, - providing at least one combustion device, - providing at least one mixing device, - feeding the provided biomass to be treated into the drying device, wherein the moisture contained in the biomass is reduced and ammonia (NH 3) is released from the biomass during the drying process, - discharging the biomass to be treated from the drying device, - feeding the biomass to be treated into the pyrolysis reactor, - pyrolyzing the biomass in the pyrolysis reactor and, in the course of this, thermally decomposing the biomass into pyrolysis coke and pyrolysis gas, - discharging the pyrolysis coke and discharging the pyrolysis gas from the pyrolysis reactor, - feeding the pyrolysis gas discharged from the pyrolysis reactor into the combustion device and combusting the pyrolysis gas thus forming a flue gas, - discharging the flue gas from the combustion device and feeding the flue gas into the mixing device, - adding oxygen (O 2) and or at least an oxygen (O 2)-containing gas to the flue gas in the mixing device and forming a drying gas, said drying gas containing, inter alia, sulfur dioxide (SO 2) and/or sulfur trioxide (SO 3), each in a gaseous aggregate state, - discharging the drying gas from the mixing device and feeding the drying gas into the drying device, - guiding the drying gas through the drying device, wherein the sulfur dioxide (SO 2) and/or the sulfur trioxide (SO 3), which is inter alia contained in the drying gas, chemically reacts with the ammonia (NH 3) to ammonium sulfite ((NH 4) 2 SO 3) and/or ammonium sulfate ((NH 4) 2 SO 4).