Flue gas desulfurization by citrate process and optimization of working parameters

In this study, model flue gas was bubbled into 0.25 L tribasic sodium citrate (TSC) solution being in 0.5 L glass absorber to remove its SO2 content. Size of gas bubbles, absorption temperature, gas flow rate, solution concentration and stirring rate were taken as working parameters to investigate their effect on SO2 removal from flue gas. The Taguchi's experimental design method was used to obtain optimum values of working parameters for SO2 saturation time of the TSC solution selected as a quality characteristic. The optimum levels of parameters to maximize the SO2 saturation time of TSC solution were coarse bubbles for gas delivery, 35 °C for absorption temperature, 1.5 slm for gas flow rate, 0.5 M for TSC solution concentration and 500 rpm for stirring rate. Under these conditions, the SO2 saturation time of the TSC solution was achieved as 511 min in average. The most effective parameters on the absorption of SO2 in TSC solutions were ranked to the least as solution concentration, gas flow rate, size of gas bubbles, absorption temperature and stirring rate.