Influence of Gas-Gas Heater on Wet Flue Gas Desulfuration

Material balance calculation was adopted to a wet flue gas desulfurization (WFGD) system for exploring impacts of gas-gas heater (GGH). Effects of GGH on flue and water consumption were analyzed. Results showed that inlet flue temperature of desulfurization tower reduced by 3.4 °C at 100% load after installation of GGH. Exhausted gas temperature of system increased by 34.9°C. The heat release of original flue in desulfurization tower reduced by 43.72%. Plume rise height was significantly improved. Water evaporation in desulfurization tower declined by 42.07%.Amount of addendum water reduced by 39.06%, and water vapor carried by flue decreased by 19.78% at the outlet of WFGD. Therefore, operation condition of flue emission is improved and water consumption decreases with GGH.

Study on Mechanism of Flue Gas Desulfuration by Using Liquid-Phase Biochemical Method

Wet Biochemical Flue Gas Desulphurization technique (WB-FGD) is combined both catalyst of transition metal with microbial metabolize to achieve flue gas desulphurization. In the self-designed device of power plant flue gas desulphurization, study the desulphurization kinetics according to the absorption solution pH, Fe3+concentration, inlet concentration of SO2, temperature and other factors. The results show that: Concentration of Fe3+is the most critical factors in the desulphurization process, the desulphurization efficiency is decreased with the increasing of Fe3+concentration, which in the range of 0~0.01mol·L-1, and the desulphurization efficiency do not change significantly with the further increasing of the concentration of Fe3+.the desulphurization efficiency is decreased with the increasing concentration of H+when pH of the solution in the range of 1.5~3.5. The efficiency of desulphurization decrease with the increasing concentration of SO2, which in the range of 1145-3432mg·L-1. The oxidation rate increase with the increasing temperature at 20~40°C.The kinetic equation and controllable parameters of changes of Fe3+concentration are obtained according to the experimental data in WB-FGD.

Calculation of the Multiphase Equilibrium of the Reaction in Wet Flue Gas Desulfuration

A computational code, which can be used to calculate gas-liquid-solid 3-phase equilibrium line, has been developed based on the principle of free energy minimum. Then the equilibrium lines of dissolution of SO2 and CaCO3 in water are obtained using the code. The results satisfy the mass and charge conservation and match well with the data in the references. Finally, multiphase equilibrium lines of the reaction in WFGD are calculated in different conditions. The results show that temperature, concentration of SO2, CO2, have different effects on the solubility of SO2 under initial conditions given in the paper. Temperature and concentration of SO2 have great effects, and the concentration of CO2 has a small effect. The solubility of SO2 increases as the partial pressure of SO2 increases, temperature decreases or the concentration of CO2 decreases. These conclusions have a great guidance on designing the tower of wet flue gas desulphurization.