Mathematical Modeling And Simulation Analysis Of Scrubber For Wet Flue Gas Desulfurization

Limestone-gypsum wet flue gas desulfurization (WFGD) technology with mature technology, steady and credible operation and high desulfurization efficiency is being applied widely for coal-fired plant all over the world. But the capital cost and operation cost are too expensive to be accepted by our consumer. In the thesis detailed researches on WFGD are carried out in order to decrease its capital cost and operation cost.SO₂ absorption properties in limestone slurry are studied based on gas-liquid-solid equilibrium theory. The effects of SO₂ and CO₂ in the flue gas and ion SO₄^2- in the slurry on SO₂ absorption capacity are analyzed based on the theory. And the minimum L/G ratio is obtained, which provides the analysis of desulfurization system with theoretical reference.A universal model of wet flue gas desulfurization has been developed using the idea of module and the method of piecewise processing. The model includes mainly two parts: the module of chemical process and the module of reactor. All important rate-determining steps are considered, such as absorption of SO₂ and CO₂, dissolution of limestone, hydrolysis of CO₂, oxidation of sulfite, and crystallization of gypsum. The model can be used for predicting the SO₂ removal efficiency for process parameters, e.g., height of the absorption section, flux of gas and liquid, initial concentration of SO₂, solid content of the slurry, liquid concentration, and liquid pH profiles.The simulation experiments based on the grid packed tower have been done, and the simulation results are in agreement with data from the power plant. The effects of gas flux,velocity of gas flow, initial concentration of SO₂, L/G ratio and liquid pH profiles are analyzed.Performance analysis and system improving can be done by use of the model and results in the thesis.