Calcium-calcium double alkali desulfurization


2022-04-21 10:50

Process principle:

Using alkaline calcium-based compounds as desulfurizers, mainly including quicklime, slaked lime, limestone, white mud (the main component of calcium carbonate), and the waste residue in the production process of Glauber's salt (the main component of calcium carbonate), etc. SO2 in the reaction occurs to achieve the purpose of desulfurization.

Main reaction:

The reaction in the desulfurization tower, SO2 reacts with calcium sulfite: CaSO3 1/2H2O+SO2+1/2H2O→Ca(HSO3)2 In this study, the saturated concentration of Ca(HSO3)2 at 30°C was determined to be 12.4g /100gH2O, no crystallization. Therefore, scaling of CaSO3·2H2O in the tower can be avoided. 

The reaction in the circulation tank, Ca(OH)2 reacts with Ca(HSO3)2 in the desulfurization solution, and regenerates CaSO3 1/2H2O, reaction: Ca(OH)2+Ca(HSO3)2→2CaSO3 1/2H2O+ H2O influence Factors: Liquid-gas ratio L/G Initial pH value Solid content Initial SO2 concentration Air tower gas velocity V System features: Lime or limestone is used as desulfurizer, no sodium-alkali consumption, low operating cost. Ensure that the system does not scale, and can continuously and stably desulfurize and remove dust. The desulfurization effect is good, and the desulfurization efficiency can reach more than 98%. The liquid gas is relatively low, and the power consumption of the circulating pump is low. The removed SO2 is separated from the water as an insoluble solid, which will not cause secondary pollution to the water body. Scope of application: Coal-fired boilers, sintering flue gas, non-ferrous metal smelting flue gas in various industries. Typical project: Shaanxi Yulin Group Sunshine Thermal Power Co., Ltd. 2×75+130t/h coal-fired boiler flue gas desulfurization project