Experimental Study On Absorption And Desorption Of Sulfur Dioxide In Flue Gas By Alkali Aluminum Sulfate

This issue sums up various kinds of flue gas desulfurization (FGD) technologies. Thealkali aluminum sulfate is a good absorbent with prominent desorption effect. It can be usedto remove sulfur for many times. This article has comprehensively researched FGDtechnology by using alkali aluminum sulfate. We are looking forward to get usefultechnological parameters to meet companies’ FGD needs.Research have been conducted on the synthetic method of alkali aluminum sulfate, thestability of solutions, the variation of pH with time, absorption effect in differentconcentration and comparison with ethylenediamine/phosphoric acid’s absorption effect.Results show that the best recipe is32g/L aluminum quantity and35%alkalinity. The alkalialuminum sulfate has a good desorption effect, the raw material are cheap and easy to get,and the products have business value, all of these lead it to be a good absorption.Intermittent and continuous experimental facility processes have been designed andconstructed. First of all, we used alkali aluminum sulfate to conduct FGD intervalexperiments and analyzed many factors’ effect on absorption and desorption. The optimalprocess show that aluminum quantity is32g/L, alkalinity is35%, absorbing liquid flow is150L/h, desorption flow rate is150L/h, desorption temperature is between90℃and99℃.What’s more, we used this absorbent to absorb and desorb repeatedly. Results show that thesecond absorption rate is still very high. Then we changed packed tower into super gravityrotating bed. Results show that the amount of SO2desorbed by super gravity rotating bed is1.7times of packed towers in the same conditions, which indicate that super gravity rotatingbed has a better desorption effect than packed tower.Based on interval experiments, continuous FGD experimental facility processes havebeen designed. We researched the influence of SO2initial concentration, the different carriergas in desorber, the temperature in bottom of desorber on absorptivity and desorption rate.Results show the variation of absorptivity and desorption rate in different SO2initialconcentration. There are some disadvantages whether use water vapors or heat liquid indesorber. So the better way is to use air for gas stripping directly.At last, experiments have been performed to research the demist performance of super gravity rotating bed which have a relationship with screen mesh texture and number. Resultsshow that nylon screen mesh has a better effect than stainess. The more number of plies, thebetter fog removal effects. In addition, liquid flow and rotate speed of revolving bed canaffect demist performance. The larger of liquid flow, the worse of demist performance. Thelarger of rotate speed, the better of demist performance.