This work includes the development of the biomass conversion technologies designed to provide the required heat demand to the district heating network. Biomass is considered here as the only fuel utilized in the proposed conversion systems as the competitive feedstock to the coal, which is mainly used in Polish heat and power plants. The first part of the work consists of the simulation of the proposed technologies. Separate utilities of the conversion systems are modeled in the proper software. Constant and variable parameters of the models are characterized as well as the investment and operation costs estimation for the each utility. A heat demand of the case study of CHP plant in Poznan is considered as the basis for estimating the energy consumption profile, which is then used in the present thesis during the integration process. Two main scenarios of the heat requirements are proposed in this work. The simulated models are next integrated and optimized in order to satisfy the demand profile. The optimization is done under the defined objective function. Finally, the optimum plant configuration is determined based on the exergy efficiency and cost objective function.