Study On Flue Gas Desulfurization Performance Of A Rotating Packed Bed

Rotating packed bed (RPB) is one of typical process intensification equipment, in which liquid is dispersed into a great deal of small elements by rotating packing. They can contact with gas more sufficiently, thereby accelerating the mixing and mass transfer processes. RPB are used in a large scale in reaction and separation process.In this study, facing the demand of flue gas desulfurization process to reach the emission concentration standards in "Boiler Air Pollutants Emission Standards" (GB13271-2014) promulgated by our country, two routes i.e. RPB connecting inseries with original desulfurization equipment and single RPB desulfurization were proposed..The slurry of CaSO3/Ca(HSO3)2 and the solution ofNa2SO3/NaHSO3were used as absorbent, respectively. The desulfurization performance and gas phase mass transfer coefficient of the RPB for the two systems were investigated. Furthermore, the sideline test of desulfurization performance was conducted in a factory.1. The study on desulfurization performance of rotating packed bed with calcium methodUsing CaSO3 and Ca(HSO3)2 mixed solution system, the absorption effect and the gas phase mass transfer coefficient of desulfurization process were studied, and the system was connected in series with original desulfurization equipment. The factors of rotational speed, gas flow rate, inletSO2 concentration and other factors on the SO2 removal efficiency and gas phase mass transfer coefficient were investigated. The results show that with the increase of rotational speed, the SO2 removal efficiency and the gas phase mass transfer coefficient increase; with the increase of gas flow, the SO2 removal efficiency decreases and gas phase mass transfer coefficient increases; with the increase of inlet SO2 concentration, the SO2 removal efficiency and gas phase mass transfer coefficient decreases. For different fillers, the SO2 removal efficiency and gas phase mass transfer coefficient results of metal wire mesh packing are better than the plastic filler, however, the metal wire mesh packing has a blockage phenomenon in the high pH. For the actual operation of industrial simulation, continuous replenishment lye is used to maintain the pH and material balance. The rotating packed bed operation is stable and it is correspond with the expected results.2. The study on desulfurization performance of rotating packed bed with sodium sulfite methodThe absorption effect and gas mass transfer coefficient were studied by using Na2SO3 and NaHSO3 mixed solution system, and the system was used for single stage rotary packed bed desulfurization. The factors of rotational speed, gas flow rate, inlet SO2 concentration and others on the SO2 removal efficiency and gas phase mass transfer coefficient were investigated. The results show that with the increase of rotational speed, the SO2 removal efficiency and the gas phase mass transfer coefficient increases; with the increase of gas flow, the SO2 removal efficiency decreases and gas phase mass transfer coefficient increases; with the increase of inlet SO2 concentration, the SO2 removal efficiency and gas phase mass transfer coefficient decreases. The absorption result of different concentrations shows that with the increase of concentration, the removal efficiency of SO2 and gas phase mass transfer coefficient increase, but when the concentration is too high the gap is not obvious. As for the actual operation of industrial simulation, continuous replenishment lye is used for maintaining the pH and material balance, the rotating packed bed operation is stable and can meet the desired effect.3. The study on industrial side of rotating packed bed desulfurizationThe SO2 absorption industrial sideline was studied by using NaSO3 and NaHSO3 mixed solution system. The handling capacity was enlarged from 200 m3/h to 500 m3/h and then investigated the actual effect of SO2 removal process through rotating packed bed under the condition of industrial siding. The effects of solution pH, rotating speed and gas liquid ratio on the removal efficiency of SO2 were investigated. With the increase of solution pH and rotational speed, the removal efficiency of SO2 improves; With the increase of gas/liquid ratio, the removal efficiency of SO2 decreases. Under the condition of industrial siding, rotating packed bed operation situation is well, the influence law of various parameters on SO2 absorption is the same as laboratory research.