Study On Adsorption Behavior Of Sulfur Nitride On Activated Alumina

In order to protect the atmospheric environment. It is important to control the emission of gaseous pollutants (SO2and NOx) and greenhouse gases (CO2) in coal-fired flue gas. Based on the development trend of integration treatment of flue gas, the research on the simultaneous removal of the three harmful gases is of great significance. This issue proposes system research on the interaction mechanism of SO2, NOx and CO2on the surface of activated alumina. Further studying on the influence of adsorbent characteristics, the oxygen and water vapor on the interaction of the three gases, which can provide theoretical basis for adsorbent design and selection. The main results are as follows:(1) A series of inorganic salt modified activated alumina adsorbents for simultaneous adsorption of SO2、NO and CO2were prepared by ultrasound-assisted equivalent-volume impregnation process. Potash is the best modifiers among the various inorganic active components. The effects of potash impregnation liquid concentration, roasting temperature, adsorption temperature, oxygen content and water vapor content on the co-adsorption of SO2、NO and CO2were studied. Experimental results show that when the potassium carbonate impregnation liquid concentration is2mol/L, the potash loading amount is35%, the co-absorption effect is the best. Alkaline alumina shows good ability to trap SO2and NO under wide operation conditions while the adsorption ability of CO2remains to be improved.(2) A series of organic amine modified activated alumina adsorbents for SO2、NO and CO2co-adsorption were prepared by mixing reflux method. Tetraethylenepentamine (TEPA) is the best organic amine modifier among the chosen amines. The effects of TEPA loading amount, adsorption temperature, oxygen content and water vapor content on the co-adsorption of SO2、NO and CO2were investigated. The experimental results show that when the TEPA loading amount is40%, the co-absorption effect is the best. Compared with alkaline alumina, amine functioned active alumina show better ability to adsorb SO2and CO2, especially for SO2, while the adsorption capacity of NO is decreased. But as the concentration of CO2is too high, the CO2adsorption ability is still needs to be improved in the adsorption system. (3) The mesoporous alumina carrier was prepared by EISA process. Mesoporous alumina shows better ability to adsorb SO2、NO and CO2than that of common activated alumina. When the potash loading amount is5%, the alkaline mesoporous alumina shows best adsorption efficiency for SO2and NO. The adsorption of CO2relied more on the potassium carbonate loading amount, when loading amount is40%, the decarburization effect is best.(4) SO2and NO shows coordination adsorption effects on the surface of alkaline mesoporous alumina. When SO2and NO are exist, both the adsorption capacities increase significantly. While CO2shows competing adsorption mechanism with SO2and NO, when CO2is added, the adsorption capacity of the three gas has a different reduce degree.(5) Mesoporous alumina grafted with TEPA has good adsorption capacity of CO2and can be applied in simultaneous adsorption of SO2、NO and CO2in coal combustion flue gas. The adsorption efficiency of amine functionalized alumina is crucial in the number of hydroxyl groups on the surface of the mesoporous alumina carrier. The more hydroxyl groups retain, the more amine grafted and stabile. Which leads to the higher co-adsorption efficiency.