This work deals with the creation of a mathematical model for calculating mass and energy balances of the energy units for utilizing the biomass combustion by computational software W2E and it is engaged in necking the validity of the balance model for the real technology unit for combustion different types of biomass. There are presented basic informations of balances and described the procedure how to solve balance calculations of energy units. Introductory part deals with biomass as a renewable energy source, which has a large potential in energy system. There are presented all its important parameters, its types, methods of treatment and utilization power production. Next chapters focus on biomass combustion devices, theirs classification and theirs technological principles. For the specific type of biomass boiler (of capacity 1 MW with movable, inclined grid) - here was created balance model. The choice of this equipment is preferred primarily by the fact that the middle capacity power boilers can be considered as the most suitable heat sources in terms of efficient combustion of biomass. Another motivation is a key objective of this work, which is creation of balance model of the unit which energy utilizes of biomass, which belong into this category of heat sources and is available for real measurements. There are presented the available computing systems for balance modeling with the preference of the analysis program W2E and MS Excel. They are verified as the best instruments for creation balance model at the practical chapter of this work. The main output of presented thesis is thus balance model developed in W2E program which has been compared and modified to the real characteristics of biomass boiler. For this purpose were used the archived data from previous measurements and new actual measurements, which focused on the acquisition of the missing operational data and verifying the reasons of variance of the model and real status. In the conclusion, there are evaluated the basic operating parameters of the technology in various operating states by W2E analysis model.

As the need for both sustainable energy production and waste minimization increases, the gasification of biomass becomes an increasingly important process. What would otherwise be considered waste can now be used as fuel, and the benefits of volume reduction through gasification are seen in the increased lifespan of landfills. Fluidized-bed gasification is a particularly robust technology, and allows for the conversion of most types of waste biomass. Within a fluidized-bed gasifier, thermal medium (sand) is heated to operating temperature (around 1350°F) and begins to fluidize due to the rapid expansion of air entering the bottom of the reactor. This fluidization allows for excellent heat transfer and contact between gases and solids, and prevents localized "hot spots" within the gasifier, thereby reducing the occurrence of ash agglomeration within the gasifier. Solids enter the middle of the gasifier and are rapidly dried and devolatilized, and the products of this step are subsequently oxidized and then reduced in the remainder of the gasifier. A syngas composed mainly of N2, H2O, CO2, CO, CH4, and H2 exits the top of the gasifier. A computer model was developed to predict the syngas composition and flow rate, as well as ash composition and mass flow rate from a fluidized-bed gasifier. A review of the literature was performed to determine the most appropriate modeling approach. A chemical kinetic model was chosen, and developed in MATLAB using the Newton-Raphson method to solve sets of 18 simultaneous equations. These equations account for mass and energy balances throughout the gasifier. The chemical kinetic rate expressions for these reactions were sourced from the literature, and some values modified to better fit the predicted gas composition to literature data.