Ověření suchých metod odsiřování

Abstract

Dissertation thesis is aimed to verify dry desulphurization methods with regards to meet the emission limit of sulfur dioxide 200 mg/mN3. The main attention is paid particularly on utilization of sodium bicarbonate and sorbent on basis of calcium hydroxide. The introduction is focused on situation of power industry in Czech Republic. Because there are deposits of coal in Czech Republic, coal fired power plants are the dominant source of energy, which participate on total power generation by 60%. However, this brings a problem in the form of SO2 emissions in which sources from category REZZO1 essentially participate. Although SO2 emissions were significantly reduced since 1990, over 200 thousand tons of SO2 is still emitted to atmosphere each year. In theoretical part are given the most frequently used methods of sulfur dioxide elimination, both the removal of sulfur from fuel and methods for SO2 reduction from flue gas. There are described the most commonly used methods. Much attention is paid to the wet desulphurization method as the most commonly used method in the Czech Republic and dry methods of desulphurization. The experimental section is devoted to tests, which took place in Power plant Třebovice and Power plant Kolín. Tests were performed on three units. It was boiler with wet bottom furnace, boiler with dry bottom furnace and boiler with stoker fired furnace. Tests only with sodium bicarbonate were performed on one unit. Tests both with sodium bicarbonate and with sorbent on the basis of calcium hydroxide were performed on the remaining units. Sorbent was fed to the flue gas tract downstream the last heat exchanging surface. Preformed tests are evaluated in conclusion, not only with regard to reduction of sulfur dioxide, but attention is also paid to analysis of ash from each test and their evaluation. This is important for further treatment of solid refuses from combustion. Also tests on different devices are compared.