A Nonequilibrium Stage Model To Simulate the Chemical Absorption of SO2

A nonequilibrium stage model was developed to simulate chemical absorption of SO2 in flue gas by sodium phosphate solution and ethylenediamine/phosphoric acid solution. The predicted values fit well with the experimental results. Using this model and the doublefilm theory, the accurate phase equilibrium constant in the nonequilibrium stage model was obtained. The absorption process of SO2 in the simulating of flue gas was predicted for different ratios of liquid flux to vapor flux (L/V) and absorber concentrations in a laboratory packed tower (0.03 m in diameter, and 0.6 m in packed section height,) using sodium phosphate buffer solution and ethylenediamine/phosphoric buffer solution. The relative error of SO2 concentration in exhaust gas between predicted and experimental results is <30%. When the SO2 concentration axial profile in liquid phase was predicted using the above nonequilibrium model, the relative error was <15%. The model can be used for the process design, optimization, and popularization.