Derived from current developments, thermal sewage sludge mono-utilization will play an increasingly important role in the future. In the context of this master thesis, essential basics on the subject of sewage sludge and sewage sludge utilization are provided. Based on this, a description of the functionality and the state of the art of plants for thermal sewage sludge mono-utilization is given. Mono-incineration enables the recovery of phosphorus from the incineration ash. For this purpose, selected processes are presented. The practical part of the work comprises the process simulation of thermal sewage sludge mono-utilization. For this, the process simulation software IPSEpro from SimTech Simulation Technology is used. The main objective is the extension of a model library existing internally at EVN Wärmekraftwerke GmbH by mathematical unit models for the field of flue gas cleaning. In particular, a mathematical modelling of dry sorption and wet scrubbing is performed, each for two operating media. On the basis of an overall model of a plant for thermal sewage sludge mono-utilization by EVN, the thermal self-sufficiency limit is determined. Furthermore, it is investigated how the calorific value of the sewage sludge entering the fluidized bed incinerator affects the generation of electricity and district heating.