Effect Of Basic Groups On CO₂ Adsorption Performance In Solid Adsorbents

Global warming is a serious environmental problem nowadays. CO2 capture is one of the most effective methods to reduce the greenhouse effect, which mainly includes Liquid phase absorption, solid phase adsorption, membrane separation and chemical looping combustion at current stage. Among them, the solid phase adsorption is a promising method depending upon its unique advantages of good regeneracy and less corrosion to equipment.In this thesis, siliceous MCM-41 is synthesized as the materials carriers. The ordered structure of MCM-41 is proved by X ray diffraction. TEPA and PEI are used as the amine source to prepare amino-functionalized materials by impregnation. The thermal stability of materials with different amine loadings are evaluated on a thermogravimetric analyzer and the results show that the materials are stable below 200℃.MCM-41 fist modified with KOH, CsOH and Ca(OH)2 before impregnated by TPEA and PEI. Chemical titration method, infrared spectroscopy and elemental analysis are used to characterize the materials. The CO2 adsorption and desorption performance of the materials are examined. The results indicate that MCM-41 modified by inorganic alkali and organic amine, show a improved CO2 adsorption capacity. The adsorption capacity of materials modified by Ca(OH)2 are higher than the materials modified by KOH and CsOH. The results show that CO2 adsorption capacity is correlative with the alkali quantity. The infrared spectroscopy analysis result indicates that the organic amine have been loaded onto materials and play a main role in the CO2 adsorption properties. Furthermore, the elemental analysis results show that the inorganic metallic elements are really loaded onto the materials which play a key role in strengthening the alkalinity of the materials.The adsorption properties of materials using MCM-41 and activated carbon as carriers are compared. The adsorption capacities of materials prepared with MCM-41 are obviously better than activated carbon. During five times cycling test, it is confirmed that the renewable performance of the materials is excellent because that the quality increment percentage variance calculated is less than 1%.