Experimental Study On Dual-pH Value Wet Flue Gas Desulfurization

Currently, the sulfur content of the coal fired in the power plant fluctuates greatly and often exceeds the design requirements of the desulfurization units; meanwhile, the national SO2emissions standards for coal-fired power plants meet a further improvement, so the existing desulfurization units need efficiency modification while the new ones need choosing the right desulfurization technology with higher SO2removal efficiency and higher purification degree. Therefore, a dual-pH value wet flue gas desulfurization experiment system was designed and established in order to study the resistance characteristics and the desulfurization performance of the dual-pH value desulfurization absorber and a model of the desulfurization efficiency of the dual-pH value wet flue gas desulfurization was built with the experimental data, which provides a technical guidance to the engineering applications and the optimization of the technology.Firstly, the dual-pH value wet flue gas desulfurization experiment system was designed and established in order to study the resistance characteristics and the desulfurization performance of the dual-pH value desulfurization absorber. The results show that the collecting bowl of the dual-pH value desulfurization tower, causing little pressure drops has a good flow character. The pressure drop of the desulfurization tower mainly results from the local resistance causing by the elbow and diameter changes of the inlet and outlet of the tower and the pressure drop causing by the grout spraying. The best pH value and solid content of the dual-pH value wet flue gas desulfurization is:the pH value of quench loop is4.8-5.0and the solid content is13%while the absorber loop is5.8-6.2and17%. Under those operating parameters, over98%SO2removal efficiency was achieved at SO2inlet concentrations of1750-3600ppm. The SO2removal efficiency of dual-pH value wet flue gas desulfurization technology is2%-3%higher than that of the traditional single pH value technology if other parameters are fixed at SO2inlet concentration of2300 ppm. The desulfurization efficiency of dual-pH value technology increases as the L/G increases and decreases as the gas velocity and the SO2inlet concentration decreases if other parameters fixed. A model of the desulfurization efficiency of the dual-pH value wet flue gas desulfurization was built by EViews with the experimental data.This study has shown that dual-pH value wet flue gas desulfurization technology has high desulfurization efficiency and high purification degree and can be applied to the renovation of existing desulfurization units and the designation and construction of the new ones.