| Abstract [eng] |
The growing demand for clean and sustainable energy, as well as national and European aspirations for energy independence, are encouraging the search for new and superior methods of energy generation. Among the promising ways of energy production can be found – biomass gasification technology. Biomass gasification is the thermochemical conversion of a carbon-based fuel at high temperature, involving the partial oxidation of fuel elements. The result of this process is synthetic (synthesis) gas (CO2, CO, H2, CH4), which can be widely used in heat production, cogeneration or modern energy generation systems. In order to get acquainted with biomass gasification technology, biomass and its potential use development, main reactions (Boudouard, coal gasification, water vapor conversion and methane formation), processes (drying, pyrolysis, oxidation and carbon gasification) and equipment with characteristics are defined. When designing gasification equipment or analyzing the possibilities of fuel utilization in energy production, there is a need to determine the structure of synthesis gas. For this purpose, based on literature sources, a mathematical model of thermodynamic equilibrium is defined, which, using the elemental fuel composition of biomass, helps to determine the concentrations of components forming synthetic gases. Using the synthesis gas calculation code, the composition of mixed wood chips is investigated: C – 48,77 %, H – 5,85 %, N – 0,05 %, S – 0,01 %, O – 44,52 %, A – 0,8 %. The curves of CO2, CO, H2, N2, CH4 concentrations showed that with increasing moisture content of wood chips (from 0% to 25%) or gasification temperature (from 700 oC to 1100 oC) – concentrations of flammable components (CO, H2, CH4) in most cases it decreases, which also reduces the calorific value of the synthesis gas (in case of moisture change: from 4,22 MJ/Nm3 to 3,24 MJ/Nm3; in case of temperature change: from 4,67 MJ/Nm3 to 3,38 MJ/Nm3). In the third part of the work, the economic possibilities of the biomass gasification micro–cogeneration power plant project are analyzed. The calculated parameters: internal rate of return – 21% (discount rate – 6%), net present value – 172,210 Eur, actual payback period – 5,72 years, show that the examined investment is efective. Sensitivity analysis, during which the support intensity (from 0% to 50%), discount rate (from 3 % to 9 %), electricity (from 70 Eur/MWh to 140 Eur/MWh) and biofuel (from 7 Eur/MWh to 17 Eur/MWh)) prices were changed, revealed that when one of the factors deteriorating the project's economic efficiency, in many cases it remains acceptable to implement. . |
