| 摘要 |
Sulfur dioxide (SO2) can be oxidized to rapidly sulfur trioxide (SO3) in a high temperature environment. It has been found that the SO2 oxidation rate can be impeded by a high rate of temperature reduction in a dynamic condition such as in a boiler and the ductwork of a power plant and an industrial plant. The mechanism of the reaction kinetics has been developed. With the understanding of the mechanism, the methods for oxidation of SO2 to form SO3 have been developed. The SO3 rich flue gas is treated with lime (CaO) in a fluidized lime reactor wherein SO3 reacts with CaO to form CaSO4 coating on the surface of CaO. The high heat generated from the SO3/CaO reaction causes the remaining SO2 to convert in the reactor to SO3 which in turn reacts with CaO to form more CaSO4. Nitrogen oxides can also be removed from flue gas by converting nitric oxide (NO) to nitrogen dioxide (NO2) via a high time rate of temperature reduction within ductwork and by sudden cooling with a spray of fine water mist or water vapor. NO2 reacts with water vapor to form nitric acid which in turn reacts with lime to form calcium nitrate Ca(NO3)2. The plant gas effluent, after treatment with the improved Lin flue gas SOx/NOx removal process, is essentially free from SOx, NOx, and particulate materials.
|
